Deciphering the photolysis products and biological concerns of triclosan under UVC and UVA.

Triclosan (TCS) is omnipresent in the environment and has drawn increasing attention due to its potential adverse effects on human health. Direct photolysis of TCS readily occurs, especially in the surface layers of waters that receive abundant ultraviolet radiation during the daytime. However, biological concerns and the identification of toxic products during TCS photolysis have been explored limitedly. Therefore, in the present work, the structural characterization of the photolysis products by UVC and UVA were performed based on the mass spectra and fragmental ions. The results displayed that TCS was more readily eliminated by UVC than UVA, and the product species were completely different when TCS was degraded by UVC and UVA, respectively. Two products, m/z 235 and m/z 252, were produced via reductive dechlorination and nucleophilic substitution with UVC, while three dioxin-like isomer products were generated by dechlorination, cyclization and hydroxylation. Furthermore, the results of biological concerns suggested that the elimination of TCS did not represent the disappearance of biological risks. Specifically, more hazardous and photolysis products were formed during TCS photolysis with ultraviolets. For instance, the dioxin-like isomer products were highly microtoxic and genotoxic, and mildly antiestrogenic. The positive findings highlighted the biological concerns of TCS photolysis by ultraviolet radiation in the aquatic environment.

[Effect of Sarcopenia on the Efficacy of Percutaneous Kyphoplasty in the Treatment of Osteoporotic Spinal Compression Fractures in Elderly Patients].

Objective To investigate the effect of sarcopenia on the efficacy of percutaneous kyphoplasty(PKP)in the treatment of osteoporotic spinal compression fracture(OSCF)in elderly patients. Methods From February 2017 to June 2018,a total of 77 elderly patients who met the inclusion and exclusion criteria were included in this study.Grip strength of dominant hand was measured by an electronic grip dynamometer with cut-off values of 27 kg for males and 16 kg for females.The cross-sectional area of the pedicle level muscle of the 12th thoracic vertebra(T12)was measured by chest CT.The skeletal muscle index(SMI)was calculated by dividing the T12 pedicle level muscle cross-sectional area by the square of body height.The SMI cut-off value used to diagnose sarcopenia was 42.6 cm2/m2for males and 30.6 cm2/m2 for females.Sarcopenia is confirmed when both grip strength and SMI are below the cut-off values.The patients with OSCF all received PKP.The patients in the sarcopenia and non-sarcopenia groups were compared in terms of age,gender,body weight,operation duration,the amount of bleeding,time to ambulation,hospital stay,visual analogue scale(VAS)before and 1 month after operation,Oswestry disability index(ODI)1 month after operation as well as the incidence of refracture within 1 year after operation. Results Gender,body weight,operation duration,the amount of bleeding and the preoperative VAS score showed no significant difference between the two groups(χ2=3.563,P=0.059;t=0.406,P=0.686;t=1.119,P=0.267;t=-0.166,P=0.868;z=-1.076,P=0.282).The patients in the sarcopenia group showed longer time to ambulation,longer hospital stay,higher VAS score and ODI 1 month after operation than those in the non-sarcopenia group(t=3.938,P<0.001;t=5.655,P<0.001;z=-4.562,P<0.001;z=-5.222,P<0.001).There was no significant difference in the incidence of refracture within 1 year after operation between the two groups(χ2=0.596,P=0.440).Linear regression results showed that age did not affect the hospital stay,rehabilitation duration,VAS score or ODI(P=0.519,P=0.870,P=0.332,P=0.126),whereas sarcopenia had significant effects(P<0.001,P=0.001,P<0.001,P<0.001). Conclusions Sarcopenia with OSCF has poorer limb function recovery.Reasonable rehabilitation exercise and dietary therapy are necessary for patients with sarcopenia.

[Aristolochic acid nephropathy: an issue worth more attention].

Aristolochic acid nephropathy (AAN), a progressive renal interstitial fibrosis frequently resulting in end stage renal disease, still remains a common chronic interstitial nephropathy in China. Therefore, great attention should be paid to AAN. This review summarized recent research progress of AAN in terms of in vivo aristolochic acid metabolism, epithelial mesenchymal transition, proteomics, immunity-inflammation, and autophagy, which will help to further understand the pathogenesis of AAN, and to search effective intervention targets.

Simultaneous alleviation of Cd availability in contaminated soil and accumulation in rice (Oryza sativa L.) by Fe-Mn oxide-modified biochar.

Fe-Mn oxide-modified biochar (BC-FM) was used to remediate Cd-contaminated soil and mitigate Cd accumulation in rice. The roles of Fe and Mn in soil Cd immobilization and in controlling Cd uptake by rice were investigated via X-ray photoelectron spectroscopy (XPS) characterization and chemical analysis. Fe and Mn loaded on BC-FM increased the removal efficiencies of CaCl2 extractable Cd in soil and Cd in pore water compared to those in only biochar (BC)-treated soil, with maximum removal rates at 67.9 % and 77.8 %, respectively. The XPS results indicated that the redox reactions of the Fe-Mn oxides on BC-FM surface affected Cd immobilization in the soil. The Fe (II/III) components on BC-FM were primarily converted to Fe3O4 in the soil system, which may form stable complexes with Cd2+ (Fe-O-Cd) during the entire rice growth period, and Cd may be bound to MnO or Mn2O3 in the form of CdMn2O4. The excellent adsorption performance of BC-FM enhanced by Fe-Mn oxides reduced the available Cd in the soil and stimulated Fe and Mn transport in rice, thereby inhibiting Cd accumulation in the aerial parts of rice. Cd concentrations in brown rice under BC-FM treatments reached the national safety standard (0.2 mg/kg, GB2762-2017). And BC-FM significantly increased the biomass of brown rice with a maximum rate of 26.8 %. These findings suggest that BC-FM could be used as an efficient material for Cd-contaminated soil remediation, and Fe-Mn plays important role in immobilizing Cd in soil and reducing Cd transport in rice.

[Characteristics and Source Apportionment of Vehicular VOCs Emissions in a Tunnel Study].

To explore the emission characteristics of volatile organic compounds (VOCs) from vehicular exhaust sources and evaporative sources with ethanol gasoline (E10) as the main fuel, VOCs sampling campaigns were carried out in the north third ring tunnel of Zhengzhou city for two consecutive weeks in December 2019. In addition, the characteristics of traffic flow and environmental information were also monitored in the tunnel. Firstly, 106 VOCs were quantified using gas chromatography/mass spectrometry (GC/MS), and then source apportionment of VOCs in the tunnel was carried out using a positive matrix factorization (PMF5.0)-chemical mass balance (CMB8.2) composite model. Finally, the ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAFP) of vehicle exhaust sources and evaporative sources were analyzed using the maximum incremental reactivity (MIR) and fractional aerosol coefficient (FAC). The results showed that ρ(VOCs) in the tunnel was (2794.5±147.4) µg·m-3 during the experiment, among which halogenated hydrocarbons[(32.4±2.0)%] accounted for the highest proportion, followed by aromatic hydrocarbons[(27.5±0.6)%] and alkanes[(23.3±0.8)%]. Source apportionment of vehicular VOCs showed that exhaust emissions (62.5%)>evaporative emissions (37.5%), whereas the contribution of OFP was that exhaust emissions (71.9%)>evaporative emissions (28.1%), and the contribution of SOAFP was that exhaust emissions (75.8%)>evaporative emissions (24.2%). The dominant components of OFP in evaporative sources were m,p-diethylbenzene, isoprene, and trans-2-pentene, whereas m,p-diethylbenzene, m,p-xylene, and 1,2,3-trimethylbenzene were the dominant components of SOAFP. The major components of OFP in exhaust sources were m,p-xylene, 1,2,4-trimethylbenzene, and 1,3,5-trimethylbenzene, whereas m,p-xylene, m,p-diethylbenzene, and 1,3,5-trimethylbenzene were the dominant components of SOAFP. In regions where ethanol gasoline is used, special attention should be paid not only to the exhaust emissions control but also to strengthening the emissions reduction of VOCs from vehicle evaporative sources, especially the high active components such as aromatic hydrocarbons and alkenes.

A comparison of three different surgery approaches and methods for neurologically intact thoracolumbar fractures: a retrospective study.

OBJECTIVES: The purpose of this study was to evaluate and compare the feasibility, safety, and efficacy of conventional open pedicle screw fixation (COPSF), percutaneous pedicle screw fixation (PPSF), and paraspinal posterior open approach pedicle screw fixation (POPSF) for treating neurologically intact thoracolumbar fractures. METHODS: We retrospectively reviewed 108 patients who were posteriorly stabilized without graft fusion. Among them, 36 patients underwent COPSF, 38 patients underwent PPSF, and 34 patients underwent POPSF. The clinical outcomes, relative operation indexes, and radiological findings were assessed and compared among the 3 groups. RESULTS: All of the patients were followed up for a mean time of 20 months. The PPSF group and POPSF group had shorter operation times, lower amounts of intraoperative blood loss, and shorter postoperative hospital stays than the COPSF group (P < 0.05). The radiation times and hospitalization costs were highest in the PPSF group (P < 0.05). Every group exhibited significant improvements in the Cobb angle (CA) and the vertebral body angle (VBA) correction (all P < 0.05). The COPSF group and the POPSF group had better improvements than the PPSF group at 3 days postoperation and the POPSF group had the best improvements in the last follow-up (P < 0.05). CONCLUSION: Both PPSF and POPSF achieved similar effects as COPSF while also resulting in lower incidences of injury. PPSF is more advantageous in the early rehabilitation time period, compared with COPSF, but POPSF is a better option when considering the long-term effects, the costs of treatment, and the radiation times.

[Study on the spectrum response of Brassica Campestris L leaf to the zinc pollution].

In the present paper, the spectrum response of Brassica Campestris L leaf to the stress of heavy metal zinc pollution was studied in three spectral rangess of the red edge position (680-740 nm), the visible spectrum (460-680 nm) and the near infrared spectrum (750-1000 nm). The results indicate that the Zn content in cabbage leaves increases and the chlorophyll level reduces with the increase in Zn concentration in soil. With the Zn content of Brassica Campestris L leaves increasing, the leaf spectral reflectivity in visible light (A1) and the range of red edge shift (S) ascends, the the leaf spectral reflectivity in the near infrared light (A2) decreases. The three indices of A1, A2 and S are fitted much linearly with the logarithm of zinc content in Brassica Campestris L leaves with the high squared regression coefficients of 0.942, 0.981 and 0.969 respectively. The regression models are reliable to estimate the zinc content in Brassica Campestris L leaves.

[Studies of relationships between Cu pollution and spectral characteristics of TritiZnm aestivum L].

The effect of Cu pollution on the Cu uptake by wheat, the characteristics of chlorophyll concentration, and the visible-near infrared spectra were studied under the condition of solution culture, and the relationships among the three indices were discussed. The results indicate that the content of Cu in TritiZnm aestivum L. increases and the concentration of chlorophyll reduces with the increase of Cu in solution. The spectral characteristics also take on the disciplinary diversification (the spectral reflectivity ascended in the visible light band and decreased in the near infrared band; the range of red edge shift decreased) with the increase of Cu in solution.

Morphological and transcriptional responses of Lycopersicon esculentum to hexavalent chromium in agricultural soil.

The carcinogenic, teratogenic, and mutagenic effects of hexavalent chromium (Cr[VI]) on living organisms through the food chain raise the immediate need to assess the potential toxicological impacts of Cr(VI) on human health. Therefore, the concentration-dependent responses of 12 Cr(VI)-responsive genes selected from a high-throughput Lycopersicon esculentum complementary DNA microarray were examined at different Cr concentrations. The results indicated that most of the genes were differentially expressed from 0.1 mg Cr/kg soil, whereas the lowest-observable-adverse-effect concentrations of Cr(VI) were 1.6 mg Cr/kg soil, 6.4 mg Cr/kg soil, 3.2 mg Cr/kg soil, and 0.4 mg Cr/kg soil for seed germination, root elongation, root biomass, and root morphology, respectively, implying that the transcriptional method was more sensitive than the traditional method in detecting Cr(VI) toxicity. Dose-dependent responses were observed for the relative expression of expansin (p = 0.778), probable chalcone-flavonone isomerase 3 (p = -0.496), and 12S seed storage protein CRD (p = -0.614); therefore, the authors propose the 3 genes as putative biomarkers in Cr(VI)-contaminated soil. Environ Toxicol Chem 2016;35:1751-1758. © 2015 SETAC.

Predicting cancerlectins by the optimal g-gap dipeptides.

The cancerlectin plays a key role in the process of tumor cell differentiation. Thus, to fully understand the function of cancerlectin is significant because it sheds light on the future direction for the cancer therapy. However, the traditional wet-experimental methods were money- and time-consuming. It is highly desirable to develop an effective and efficient computational tool to identify cancerlectins. In this study, we developed a sequence-based method to discriminate between cancerlectins and non-cancerlectins. The analysis of variance (ANOVA) was used to choose the optimal feature set derived from the g-gap dipeptide composition. The jackknife cross-validated results showed that the proposed method achieved the accuracy of 75.19%, which is superior to other published methods. For the convenience of other researchers, an online web-server CaLecPred was established and can be freely accessed from the website http://lin.uestc.edu.cn/server/CalecPred. We believe that the CaLecPred is a powerful tool to study cancerlectins and to guide the related experimental validations.

Quantitative structure-property relationship of aromatic sulfur-containing carboxylates.

Based on quantum chemical calculations, TLSER model (theoretical linear solvation energy relationships) and atomic charge approach were applied to model the partition properties(water solubility and octanol/water partition coefficient) of 96 aromatic sulfur-containing carboxylates, including phenylthio, phenylsulfinyl and phenylsulfonyl carboxylates. In comparison with TLSER models, the atomic charge models are more accurate and reliable to predict the partition properties of the kind of compounds. For the atomic charge models, the molecular descriptors are molecular surface area (S), molecular shape (O), weight( MW), net charges on carboxyl group (QOC), net charges of nitrogen atoms (QN), and the most negative atomic charge (q-) of the solute molecule. For water solubility (log SW) and octanol/water partition coefficient (log KOW), the correction coefficients r2adj (adjusted for degrees of freedom) are 0.936 and 0.938, and the standard deviations are 0.364 and 0.223, respectively.

Prediction of liquid chromatography retention factors for alpha-branched phenylsulfonyl acetates using quantum chemical descriptors.

The logarithms of retention factors normalized to a hypothetical pure water eluent (log kw) were determined on a reversed-phase high-performance liquid chromatography(RP-HPLC) column (Li Chrosorb RP-18 column) for 20 new alpha-branched phenylsulfonyl acetates. The atomic charge method was applied to develop quantitative structure-retention relationships (QSRRs). Among the available geometric and electronic descriptors, surface area (S), ovality (O), and the charge of carboxyl group (Qoc) are significant. In the model, the contribution of surface area (S) is the greatest. The molecular mechanism of retention was demonstrated through the model. With the correlation coefficient (r2adj, adjusted for degrees of freedom) of 0.964, the standard error of 0.164 and the F-value of 170.39, the model has good predictive capacity.

Evaluating the exchange of DDTs between sediment and water in a major lake in North China.

A large-scale sampling program was conducted to simultaneously collect surface water, overlying water, pore water, and sediment samples at monthly intervals between March and December 2010 from Baiyangdian Lake, North China to assess the distribution of DDTs and determine the net direction of sediment-water exchange. Total DDT concentrations ranged 2.36-22.4 ng/L, 0.72-21.9 ng/L, 2.25-33.7 ng/L, and 4.42-7.29 ng/g in surface water, overlying water, pore water, and sediments, respectively, which were at the intermediate levels compared to those of other area around the world. Seasonal variations of DDTs were featured by higher concentration in summer. This was likely associated with (a) the increase of land runoff in the summer and (b) application of dicofol and DDT-containing antifouling paints for ships in summer. Sediment-water fugacity ratios of the DDT isomers were used to predict the direction of the sediment-water exchange of these isomers. The sediment-surface water, sediment-overlying water, and sediment-pore water fugacity ratios of DDT isomers averaged 0.34, 0.44, and 0.1, which are significantly lower than the equilibrium status (1.0), suggesting that the net flux direction were from the water to sediment and the sediment acted as a sink for the DDTs. The difference of DDT concentrations between sediment and water samples was found to be an important factor affecting the diffusion of DDT from the water to sediment.

Seed germination, root elongation, root-tip mitosis, and micronucleus induction of five crop plants exposed to chromium in fluvo-aquic soil.

The present study aimed to determine the toxic effects of chromium (Cr) on cabbage (Brassica oleracea), cucumber (Cucumis sativus), lettuce (Lactuca sativa), wheat (Triticum aestivum), and corn (Zea mays), and identify the sensitive plant species and appropriate bioassays for potential use in phytotoxicity assessment of Cr in soil. Results showed that seed germination might not be a sensitive assay for assessing Cr toxicity because at most of the Cr levels there were no toxic effects. Root elongation was more sensitive to Cr than seed germination. The lowest concentration of adverse effect (LOAEC) of lettuce was 20 mg Cr/kg(-1) soil, and that of the other 4 species was 50 mg Cr/kg(-1) soil. The mitotic index fluctuated with increasing Cr concentration, thus it was insufficient to assess toxicity of Cr in soil. However, micronucleus assay showed that 5 mg Cr/kg(-1) soil caused a significant increase in micronucleus frequency in cabbage, cucumber, and lettuce. For wheat and corn, however, the LOAEC was 20 and 50 mg/Cr/kg(-1) soil, respectively. Furthermore, the analysis of Cr accumulation showed that lettuce significantly accumulated Cr for all the tested concentrations. However, corn and wheat significantly accumulated Cr only with the highest tested dose. This may explain the higher inhibitory effects of Cr on root growth. It can be concluded that root elongation and micronucleus assay are good indicators to assess the phytotoxicity of Cr in soil. Lettuce is the most sensitive species for indicating the toxicity of Cr in soil.

[Levels of polychlorinated biphenyls in adolescents' hair from Gongzhuling, Jilin].

Adolescents' (12-18) hair samples (n = 23) collected from Gongzhuling Jilin were analyzed for 30 polychlorinated biphenyl (PCB) congeners by gas chromatograph-mass spectrometer (GC-MS). The distribution characteristics, sources and relationship with genders of PCBs in adolescents' hair were addressed as well. The results indicated that the detection frequency of PCBs were 100% with average concentration of (68.85 +/- 36.72) ng x g(-1) and detection range from 11.66 ng x g(-1) to 127.86 ng x g(-1), respectively. This region was contaminated to some extent. CB-28, CB-52, CB-87 and CB-82 were the major congeners which occupied 62%. Penta-CBs were the dominant contributors (39%), followed by tetra-CBs (29%) and tri-CBs (18%). The different distributions of PCBs congeners in hair from other human tissues and the air are believed to be the fact that PCBs in human hair not only came from endogenous dietary uptake of the contaminants, but also from exogenous atmospheric deposition. The results clearly indicated that these pollutants mainly came from industrial pollution. When gender was considered, significantly higher concentrations for most of the investigated contaminants were found in female compared with male.