Porcine IKKε is involved in the STING-induced type I IFN antiviral response of the cytosolic DNA signaling pathway.

The cyclic GMP-AMP synthase and stimulator of interferon (IFN) genes (cGAS-STING) pathway serves as a crucial component of innate immune defense and exerts immense antiviral activity by inducing the expression of type I IFNs. Currently, STING-activated production of type I IFNs has been thought to be mediated only by TANK-binding kinase 1 (TBK1). Here, we identified that porcine IKKε (pIKKε) is also directly involved in STING-induced type I IFN expression and antiviral response by using IKKε-/- porcine macrophages. Similar to pTBK1, pIKKε interacts directly with pSTING on the C-terminal tail. Furthermore, the TBK1-binding motif of pSTING C-terminal tail is essential for its interaction with pIKKε, and within the TBK1-binding motif, the leucine (L) 373 is also critical for the interaction. On the other hand, both kinase domain and scaffold dimerization domain of pIKKε participate in the interactions with pSTING. Consistently, the reconstitution of pIKKε and its mutants in IKKε-/- porcine macrophages corroborated that IKKε and its kinase domain and scaffold dimerization domain are all involved in the STING signaling and antiviral function. Thus, our findings deepen the understanding of porcine cGAS-STING pathway, which lays a foundation for effective antiviral therapeutics against porcine viral diseases.

Specific Monoclonal Antibodies against African Swine Fever Virus Protease pS273R Revealed a Novel and Conserved Antigenic Epitope.

The African swine fever virus (ASFV) is a large enveloped DNA virus that causes a highly pathogenic hemorrhagic disease in both domestic pigs and wild boars. The ASFV genome contains a double-stranded DNA encoding more than 150 proteins. The ASFV possesses only one protease, pS273R, which is important for virion assembly and host immune evasion. Therefore, the specific monoclonal antibody (mAb) against pS273R is useful for ASFV research. Here, we generated two specific anti-pS273R mAbs named 2F3 and 3C2, both of which were successfully applied for ELISA, Western blotting, and immunofluorescence assays. Further, we showed that both 2F3 and 3C2 mAbs recognize a new epitope of N terminal 1-25 amino acids of pS273R protein, which is highly conserved across different ASFV strains including all genotype I and II strains. Based on the recognized epitope, an indirect ELISA was established and was effective in detecting antibodies during ASFV infection. To conclude, the specific pS273R mAbs and corresponding epitope identified will strongly promote ASFV serological diagnosis and vaccine research.

Task-Similarity-Based VNF Aggregation for Air-Ground Integrated Networks.

In a harsh environment, function aggregation of air-ground integrated network service function chaining (SFC) deployment can easily cause network load imbalance, which affects the network security and reliability. In this study, a task-similarity-based virtual network function (VNF) aggregation scheme was proposed. It considered air-ground network resource consumption and load balance before SFC mapping. A model for selecting VNFs to be aggregated based on task similarity was built. The tasks were classified based on their similarity. Furthermore, the VNFs to be aggregated were selected within the class under the constraints of the underlying physical resources. Load balancing was achieved by adjusting the similarity threshold. Moreover, an SFC mapping selection scheme based on network resource awareness was used to obtain the most suitable physical nodes for single-chain and multi-chain mapping according to various attributes of physical network nodes. The simulation results indicated that the proposed scheme with a better load balance design outperformed existing works on VNF aggregation. We also demonstrated that the task-similarity-based scheme was resource-consumption efficient and effective.

Comparison of UV-based advanced oxidation processes for the removal of different fractions of NOM from drinking water.

This study examined the effectiveness for degradation of hydrophobic (HPO), transphilic (TPI) and hydrophilic (HPI) fractions of natural organic matter (NOM) during UV/H2O2, UV/TiO2 and UV/K2S2O8 (UV/PS) advanced oxidation processes (AOPs). The changing characteristics of NOM were evaluated by dissolved organic carbon (DOC), the specific UV absorbance (SUVA), trihalomethanes formation potential (THMFP), organic halogen adsorbable on activated carbon formation potential (AOXFP) and parallel factor analysis of excitation-emission matrices (PARAFAC-EEMs). In the three UV-based AOPs, HPI fraction with low molecular weight and aromaticity was more likely to degradate than HPO and TPI, and the removal efficiency of SUVA for HPO was much higher than TPI and HPI fraction. In terms of the specific THMFP of HPO, TPI and HPI, a reduction was achieved in the UV/H2O2 process, and the higest removal rate even reached to 83%. UV/TiO2 and UV/PS processes can only decrease the specific THMFP of HPI. The specific AOXFP of HPO, TPI and HPI fractions were all able to be degraded by the three UV-based AOPs, and HPO content is more susceptible to decompose than TPI and HPI content. UV/H2O2 was found to be the most effective treatment for the removal of THMFP and AOXFP under given conditions. C1 (microbial or marine derived humic-like substances), C2 (terrestrially derived humic-like substances) and C3 (tryptophan-like proteins) fluorescent components of HPO fraction were fairly labile across the UV-based AOPs treatment. C3 of each fraction of NOM was the most resistant to degrade upon the UV-based AOPs. Results from this study may provide the prediction about the consequence of UV-based AOPs for the degradation of different fractions of NOM with varied characteristics.

Experimental and theoretical investigation on degradation of dimethyl trisulfide by ultraviolet/peroxymonosulfate: Reaction mechanism and influencing factors.

With a large amount of domestic sewage and industrial wastewater discharged into the water bodies, sulfur-containing organic matter in wastewater produced volatile organic sulfide, such as dimethyl trisulfide (DMTS) through microorganisms, caused the potential danger of drinking water safety and human health. At present, there is still a lack of technology on the removal of DMTS. In this study, the ultraviolet/peroxymonosulfate (UV/PMS) advanced oxidation processes was used to explore the degradation of DMTS. More than 90% of DMTS (30 µg/L) was removed under the conditions of the concentration ratio of DMTS to PMS was 3:40, the temperature (T) was 25 ± 2℃, and 10 min of irradiation by a 200 W mercury lamp (365 nm). The kinetics rate constant k of DMTS reacting with hydroxyl radical (HO·) was determined to be 0.2477 min-1. Mn2+, Cu2+ and NO3- promoted the degradation of DMTS, whereas humic acid and Cl- in high concentrations inhibited the degradation process. Gas chromatography-mass spectrometry was used to analyze the degradation products and the degradation intermediates were dimethyl disulfide and methanethiol. Density functional theory was used to predict the possible degradation mechanism according to the frontier orbital theory and the bond breaking mechanism of organic compounds. The results showed that the SS, CS and CH bonds in DMTS molecular structure were prone to fracture in the presence of free radicals, resulting in the formation of alkyl radicals and sulfur-containing radicals, which randomly combined to generate a variety of degradation products.

Characterization of femtosecond laser-induced grating scattering of a continuous-wave laser light in air.

Nanosecond laser-induced grating scattering/spectroscopy (LIGS) technique has been widely applied for measuring thermodynamic parameters such as temperature and pressure in gaseous and liquid media. Recently, femtosecond (fs) laser was demonstrated to induce the grating and develop the fs-LIGS technique for gas thermometry. In this work, we systematically investigated the fs-LIGS signal generation using 35 fs, 800 nm laser pulses at 1 kHz repetition rate in ambient air by varying the pump laser energies, the probe laser powers and the temporal delays between two pump laser pulses. The stability of single-shot fs-LIGS signal was studied, from which we observed that the signal intensity exhibits a significant fluctuation while the oscillation frequency shows a much better stability. A 4.5% precision of the oscillation frequency was achieved over 100 single-shot signals. By using a previously-developed empirical model, the fs-LIGS signals were fitted using nonlinear least-squares fitting method, by which crucial time constants characterizing the signal decay process were extracted and their dependences on the pump laser energy were studied. From the measured results and theoretical analysis, we found that the appropriate range of the overall pump laser energy for reliable fs-LIGS measurements is approximately located within 80 ∼ 300 µJ. The limitations on the accuracy and precision of the fs-LIGS measurements, the origin of destructive influence of plasma generation on the signal generation as well as the electrostriction contribution were also discussed. Our investigations could contribute to a better understanding of the fs-LIGS process and further applications of the technique in single-shot gas thermometry and pressure measurements in various harsh conditions.

Gas-phase pressure measurement using femtosecond laser-induced grating scattering technique.

Gas-phase pressure measurements remain challenging in situations where local pressure rapidly changes or in hostile environments such as turbulent combustion. In this work, we demonstrate the implementation of the recently developed femtosecond laser-induced grating scattering (fs-LIGS) technique for pressure measurement in ambient air. With an overall femtosecond laser pulse energy of 185 µJ, fs-LIGS signals were generated for various gas pressure ranging from 0.2 to 3.0 bar. By theoretically fitting the signal and extracting the time constant of the stationary density modulation damping, the pressure is successfully derived. The derived values were compared to the gauge pressure, which shows a quasi-linear dependence with a slope of 0.96, suggesting the feasibility of the fs-LIGS technique for gas-phase pressure measurements.

Resonant Perfect Absorption Yielded by Zero-Area Pulses.

We propose and study the manipulation of the macroscopic transient absorption of an ensemble of open two-level systems via temporal engineering. The key idea is to impose an ultrashort temporal gate on the polarization decay of the system by transient absorption spectroscopy, thus confining its free evolution and the natural reshaping of the excitation pulse. The numerical and analytical results demonstrate that even at moderate optical depths, the resonant absorption of light can be reduced or significantly enhanced by more than 5 orders of magnitude relative to that without laser manipulation. The achievement of the quasicomplete extinction of light at the resonant frequency, here referred to as resonant perfect absorption, arises from the full destructive interference between the excitation pulse and its subpulses developed and tailored during propagation, and is revealed to be connected with the formation of zero-area pulses in the time domain.

Effect of Mobile Phone App-Based Interventions on Quality of Life and Psychological Symptoms Among Adult Cancer Survivors: Systematic Review and Meta-analysis of Randomized Controlled Trials.

BACKGROUND: Most patients with cancer experience psychological or physical distress, which can adversely affect their quality of life (QOL). Smartphone app interventions are increasingly being used to improve QOL and psychological outcomes in patients with cancer. However, there is insufficient evidence regarding the effect of this type of intervention, with conflicting results in the literature. OBJECTIVE: In this systematic review and meta-analysis, we investigated the effectiveness of mobile phone app interventions on QOL and psychological outcomes in adult patients with cancer, with a special focus on intervention duration, type of cancer, intervention theory, treatment strategy, and intervention delivery format. METHODS: We conducted a literature search of PubMed, Web of Science, the Cochrane Library, Embase, Scopus, China National Knowledge Infrastructure, and WanFang to identify studies involving apps that focused on cancer survivors and QOL or psychological symptoms published from inception to October 30, 2022. We selected only randomized controlled trials that met the inclusion criteria and performed systematic review and meta-analysis. The standardized mean difference (SMD) with a 95% CI was pooled when needed. Sensitivity and subgroup analyses were also conducted. RESULTS: In total, 30 randomized controlled trials with a total of 5353 participants were included in this meta-analysis. Compared with routine care, app interventions might improve QOL (SMD=0.39, 95% CI 0.27-0.51; P<.001); enhance self-efficacy (SMD=0.15, 95% CI 0.02-0.29; P=.03); and alleviate anxiety (SMD=-0.64, 95% CI -0.73 to -0.56; P<.001), depression (SMD=-0.33, 95% CI -0.58 to -0.08; P=.009), and distress (SMD=-0.34, 95% CI -0.61 to -0.08; P=.01). Short-term (duration of ≤3 months), physician-patient interaction (2-way communication using a smartphone app), and cognitive behavioral therapy interventions might be the most effective for improving QOL and alleviating adverse psychological effects. CONCLUSIONS: Our study showed that interventions using mobile health apps might improve QOL and self-efficacy as well as alleviate anxiety, depression, and distress in adult cancer survivors. However, these results should be interpreted with caution because of the heterogeneity of the interventions and the study design. More rigorous trials are warranted to confirm the suitable duration and validate the different intervention theories as well as address methodological flaws in previous studies. TRIAL REGISTRATION: PROSPERO CRD42022370599; https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=370599.

Effective removal of Cu(II), Pb(II) and Cd(II) by sodium alginate intercalated MgAl-layered double hydroxide: adsorption properties and mechanistic studies.

To improve the adsorption efficiency of layered double hydroxides (LDHs) for heavy metals, a novel sodium alginate (SA) intercalated MgAl-LDH (SA-LDH) was synthesized in this work. SA-LDH was characterized by XRD, FTIR, XPS and employed as adsorbent for Cd(II), Pb(II), Cu(II) elimination. Adsorbent dosage, initial pH and contact time, which are regarded as several key parameters, were optimized. The results showed that SA-LDH exhibited better adsorption performance compared with the pristine MgAl-LDH. The maximum adsorption capacities of SA-LDH for Cu(II), Pb(II) and Cd(II) reached 0.945, 1.176 and 0.850 mmol/g, respectively. The possible mechanisms were analyzed by XPS, XRD and FTIR. The results showed that Cd(II), Pb(II) and Cu(II) may be removed by SA-LDH via (i) bonding or complexation with Sur-OH or Sur-O- of SA-LDH, (ii) precipitation of metal hydroxides or carbonates, (iii) isomorphic substitution, and (iv) chelation with -COO- in the interlayers. This work provides an effective method for the development of LDH-based adsorbent and the treatment of wastewater containing heavy metals.

The roles of FgPEX2 and FgPEX12 in virulence and lipid metabolism in Fusarium graminearum.

Fusarium head blight (FHB) is a wheat disease with a worldwide prevalence, caused by Fusarium graminearum. Peroxisomes are ubiquitous in eukaryotic cells and are involved in various biochemical phenomena. FgPEX2 and FgPEX12 encode RING-finger peroxins PEX2 and PEX12 in F. graminearum. This study aimed to functionally characterize FgPEX2 and FgPEX12 in F. graminearum. We constructed deletion mutants of FgPEX2 and FgPEX12 via homologous recombination. The ΔPEX2 and ΔPEX12 mutants displayed defects in sexual and asexual development, virulence, cell wall integrity (CWI), and lipid metabolism. Deletion of FgPEX2 and FgPEX12 significantly decreased deoxynivalenol production. Furthermore, fluorescence microscopic analysis of the subcellular localization of GFP-PMP70 and GFP-HEX1 revealed that FgPEX2 and FgPEX12 maintain Woronin bodies. These results show that FgPEX2 and FgPEX12 are required for growth, conidiation, virulence, cell wall integrity, and lipid metabolism in F. graminearum and do not influence their peroxisomes.

Disinfection characteristics of Pseudomonas peli, a chlorine-resistant bacterium isolated from a water supply network.

Lack of microbial contamination is crucial for drinking water quality and safety. Chlorine-resistant bacteria in drinking water distribution systems pose a threat to drinking water quality. A bacterium was isolated from an urban water supply network in northern China and identified as Pseudomonas peli by 16S rDNA gene analysis. This P. peli strain had high chlorine tolerance. The CT value (the product of disinfectant concentration and contact time) to achieve 3 lg unit (i.e. 99.9%)-inactivation of this P. peli isolate was 51.26-90.36 mg min/L, inversely proportional to the free chlorine concentration. Chlorine dioxide could inactivate the bacterium faster and more efficiently than free chlorine, as shown by flow cytometry. Thiazole orange plus propidium iodide staining indicated that free chlorine and chlorine dioxide inactivated P. peli primarily by disrupting the integrity and permeability of the cell membrane. The P. peli was also sensitive to ultraviolet (UV) radiation; a UV dose of 40 mJ/cm2 achieved 4 lg unit (99.99%)-inactivation. The Hom model was more suitable for analyzing the disinfection kinetics of P. peli than the Chick and Chick-Watson models.

Identification and inactivation of Gordonia, a new chlorine-resistant bacterium isolated from a drinking water distribution system.

Chlorine-resistant bacteria threaten drinking water safety in water distribution systems. In this study, a novel chlorine-resistant bacterium identified as Gordonia was isolated from the drinking water supply system of Jinan City for the first time. We examined the resistance and inactivation of the isolate by investigating cell survival, changes in cell morphology, and the permeability of cell membranes exposed to chlorine. After 240 min chlorine exposure, the chlorine residual was greater than 0.5 mg L-1 and the final inactivation was about 3 log reduction, which showed that the Gordonia strain had high chlorine tolerance. Flow-cytometric analysis indicated that, following sodium hypochlorite treatments with increasing membrane permeability, culturable cells enter a viable but nonculturable state and then die. We also investigated the inactivation kinetics of Gordonia following chlorine dioxide and ultraviolet radiation treatment. We found that these treatments can effectively inactivate Gordonia, which suggests that they may be used for the regulation of chlorine-resistant microorganisms.

Ultraviolet-mediated peroxymonosulfate diminution of earthy and musty compound trichloroanisole in water.

Taste and odor (T&O) problem in water is one of the main obstacles to improve the quality of drinking water, and efficient water treatment processes are urgently needed to control T&O compounds. Ultraviolet-mediated peroxymonosulfate (UV/PMS) diminution of trichloroanisole (TCA) in water was investigated in this paper. The treatment of 2,3,6-trichloroanisole (2,3,6-TCA) by three advanced oxidation processes (UV, UV/H2O2 and UV/PMS) was compared, and UV/PMS stood out. SO4•- and HO• were produced in the UV/PMS, and their specific contributions to 2,3,6-TCA oxidation were investigated. The competitive kinetic model was applied to determine the second-order reaction rate between 2,3,6-TCA and SO4•- or HO•. The products of 2,3,6-TCA generated in UV/PMS were analyzed with gas chromatography/high resolution-mass spectrometry (GC/HR-MS), and the degradation mechanism was proposed. The effects of water matrices (chloride, bicarbonate and humic acid) on UV/PMS performance were studied, and the decontamination of 2,3,6-TCA in real water was carried out. The disinfection byproducts (DBPs) alteration from 2,3,6-TCA by UV/PMS - chlorination treatment was explored. Overall, UV/PMS can effectively deal with the T&O pollution of TCA in water.

Effects of Sulfamethoxazole Exposure on the Growth, Antioxidant System of Chlorella vulgaris and Microcystis aeruginosa.

Sulfamethoxazole (SMZ) is a kind of sulfonamides antibiotic, which is widely used in human life. This study investigated the effects of SMZ on physiological and biochemical indexes of Chlorella vulgaris (C. vulgaris) and Microcystis aeruginosa (M. aeruginosa) for 35-day. The results showed that SMZ inhibited the growth and Chl-a content of C. vulgaris and M. aeruginosa, and growth inhibition rate was 8.06%-95.86%, Chl-a content decreased 2.44%-98.04%. SMZ resulting in increased SOD and CAT activity and destroyed the dynamic balance of antioxidant system. In addition, SMZ increased the content of malondialdehyde (MDA) in algae, destroyed the cell membrane to a certain extent, which was 1.8-7.3 folds higher than the control group. High concentration of SMZ can make algae cells exceed the limit of cell antioxidant capacity. Coupled with the serious damage of cell membrane, algae cells begin to appear a large number of death phenomenon.

FgPEX1 and FgPEX10 are required for the maintenance of Woronin bodies and full virulence of Fusarium graminearum.

Peroxisomes are ubiquitous single-membrane-bound organelles that perform a variety of biochemical functions in eukaryotic cells. Proteins involved in peroxisomal biogenesis are collectively called peroxins. Currently, functions of most peroxins in phytopathogenic fungi are poorly understood. Here, we report identification of PEX1 and PEX10 in the phytopathogenic fungus, Fusarium graminearum, namely FgPEX1 and FgPEX10, the orthologs of yeast ScPEX1 and ScPEX10. To functionally characterize FgPEX1 and FgPEX10, we constructed deletion mutants of FgPEX1 and FgPEX10 (ΔPEX1 and ΔPEX10) by targeting gene-replacement strategies. Our data demonstrate that both mutants displayed reduced mycelial growth, conidiation, and production of perithecia. Deletion of FgPEX1 and FgPEX10 resulted in a shortage of acetyl-CoA, which is an important reason for the reduced deoxynivalenol production and inhibited virulence of F. graminearum. Moreover, ΔPEX1 and ΔPEX10 showed an increased accumulation of lipid droplets and endogenous reactive oxygen species. In addition, FgPEX1 and FgPEX10 were found to be involved in the maintenance of cell wall integrity and Woronin bodies.

Comparative transcriptome profiling and characterization of gene expression for ovarian differentiation under RU486 treatment.

17α, 20ß-dihydroxypregn-4-en-3-one (17α, 20ß-DP, DHP), a teleost specific biologically active progestin, has been proved to play a critical role in oocytes maturation, ovulation and spermiation. RU486 (Mifepristone, an antagonist of progestin receptor) has been applied in contraceptives, abortion and hormone therapy in clinical medicine. To get further insights into the molecular mechanisms of nuclear progestin receptor (Pgr) activated ovarian differentiation and maintenance, we conducted comparative gonadal transcriptome analysis, and investigated histological and transcriptional differences using 4 months after hatching (mah) RU486-treated XX and control XX/XY Nile tilapia (Oreochromis niloticus). DESeq analysis identified 7148 DEGs (differentially expressed genes) between RU486-treated and control XX gonads, while merely 442 DEGs were screened between the gonads of RU486-treated XX and control XY fish highlighting that RU486 treatment set forwards masculinity in XX fish. Comprehensive analysis of gene hierarchical clustering revealed that RU486 treatment in XX fish resulted in robust changes of gene expression profiles. In comparison with XX group, female-dominant genes were significantly repressed in RU486 treated XX fish gonads. Moreover, most parts of down-regulated genes in wild type female were evidently up-regulated genes in RU486-treated XX fish gonads. Comparing with control XY group, the majority of male-dominant genes represent a high level of expression. However, RU486-treatment led to an up-regulation of a cluster genes specifically which showed relative lower expression in both control XX and XY group. RU486-treatment mediated global changes of gene expression profiles in steroidogenesis, germ cell differentiation and follicular cell trans-differentiation were verified by quantitative PCR. Both morphological and immunohistochemistry results further proved that RU486 treatment initiates testicular-like gonads development in XX fish via simultaneously enhancing the male responsive genes and suppressing the female-dominant genes. Moreover, RU486 treatment caused significant decline of fshr, lhr and increase of ars. Taken together, our data confirms blocking of DHP physiology by RU486 treatment induces masculinization in XX gonad preferably via repressing of gonadotropin physiology, germ cell differentiation and promoting follicular trans-differentiation in teleosts.

[Phenotypic and genetic analysis of a boy with 3p26.3-pter deletion and 7q31.33-qter duplication].

OBJECTIVE: To delineate the nature and origin of chromosomal copy number variants (CNVs) in a boy with mental retardation and multiple congenital malformation. METHODS: The karyotypes of the patient and his parents were analyzed with routine G-banded chromosomal analysis. Genome DNA was analyzed by next generation sequencing (NGS). RESULTS: The patient was found to harbor a structural aberration involving chromosome 3p. The karyotype of his father was 46,XY,t(3;7)(p26;q31), while his mother was found to be normal. NGS analysis of the patient revealed a 2.16 Mb microdeletion at 3p26.3-pter and a duplication at 7q31.33-qter. CONCLUSION: The structural aberration of 3p carried by the patient has derived from his father whom carried a balanced translocation of t(3;7), and his karyotype was finally determined as 46,XY,der(3) t(3;7)(p26.3;q31.33)pat. The abnormal phenotype of the patient can probably be attributed to the presence of 3p26.3-pter microdeletion and 7q31.33-qter duplication.

Radiological studies on the best entry point and trajectory of anterior cervical pedicle screw in the lower cervical spine.

OBJECTIVE: To explore the best entry point and trajectory of anterior cervical transpedicular screws in the lower cervical spine by radiological studies, and provide reference for clinical application. METHODS: Fifty patients were scanned by computed tomography and confirmed no obvious defect of the cervical spine. On horizontal axis, camber angle (α) and axial length (AL) were measured from C3 to C7. On sagittal view, the cranial or caudal angle (ß) and sagittal length (SL) were also measured from C3 to C7. On the sagittal and horizontal planes vertebrae were respectively divided into four areas, ordered 1-4, on the anterior side of the pedicle. The areas and angles of pedicle intersect into the vertebral body were recorded. We inserted six anterior pedicle screws into the lower cervical spine of three patients by this technique. RESULTS: On transverse plane, camber angle (α) of C3-C5 increased gradually, while it decreased from C5 to C7. On sagittal view, C3 and C4 pedicles showed cranial tilting, while C5 to C7 were caudally tilted. AL and SL values increased gradually from C3 to C7. The number of the intersections of C3-C7 in each area was also different. Six pedicle screws of three cases were inserted into the lower cervical spine with proper placement and no complications. CONCLUSION: Anterior transpedicular screw (ATPS) is a theoretically feasible option for internal fixation. The technique described in this paper was subsequently used in three patients without complication. Future improvement of ATPS insertion remains necessary for this technically demanding procedure.

Degradation of different fractions of natural organic matter in drinking water by the UV/persulfate process.

The existence of natural organic matter (NOM) causes many problems in drinking water treatment processes. The degradation of different fractions of NOM in drinking water was studied using the ultraviolet/persulfate (UV/PS) process. The NOM was separated into hydrophobic (HPO), transition hydrophilic (TPI) and hydrophilic (HPI) fractions by reverse osmosis and XAD series resins. The effects of degradation were evaluated by dissolved organic carbon (DOC), UV254, three-dimensional fluorescence-parallel factor analysis (EEM-PARAFAC), and trihalomethane formation potential (THMFP). The results showed that UV/PS process could remove the three fractions of DOC, UV254, as well as the fluorescent components humic acid-like (C1 and C2) and protein-like (C3). The maximum removal rates of DOC of HPO, TPI, and HPI fractions were 34.6%, 38.4%, and 73.9%, respectively, and the maximum removal rates of UV254 were 72.1%, 86.3%, and 86.8%, respectively. The removal rate of the three fluorescent components can reach 100%, and C3 is easier to remove than C1 and C2 under the low PS dosage conditions. The order of kinetic degradation rate constant of UV254 first-order reaction is HPI > TPI > HPO. The optimum pH conditions for the degradation of HPO, TPI, and HPI fractions were acidic, basic, and neutral, respectively. The specific THMFP of HPO was higher than that of TPI and HPI. The specific THMFP of HPO and TPI fractions increased with the increase of radiation time, while the HPI fraction showed the opposite trend. THMFP has different degrees of correlation with DOC, UV254, C1, and C2. This study can provide a theoretical basis for the selection of the UV/PS process for drinking water sources containing NOM with different characteristics.