Tris(1,3-dichloro-2-propyl)phosphate Induces Mass Mortality of Crucian Carp (Carassius carassius) Embryos in Taihu Lake.

Global fishery resources have been declining for decades, leading some fisheries to collapse. Although the decline is partly due to man-made chemical contamination, causal chemicals have been identified in only a few cases. We conducted consecutive 3-year investigations of embryonic mortality in Taihu Lake, China, including heavily contaminated northern areas, including Zhushan (ZS), Meiliang (ML), and Gonghu (GH), and the less polluted southeastern Suzhou (SZ). In 2016, 65.8% of crucian carp (Carassius carassius) embryos collected from ZS died before hatching, a substantially higher mortality rate than those observed in ML (21.7%), GH (15.2%), and SZ (2.2%). In 2017, the embryonic mortality rates were 38.8% in ZS, 1.3% in ML, 6.9% in GH, and 3.5% in SZ, and these rates strongly correlated with the concentrations of tris(1,3-dichloro-2-propyl)phosphate (TDCIPP): 104.2, 1.8, 4.6, and 4.1 ng/g lipid weight (lw) in embryos from ZS, ML, GH, and SZ, respectively. In 2018, embryonic mortality decreased to 4.0% in ZS and 1.2% in GH, consistent with decreases in embryonic TDCIPP concentrations to 17.1 and 1.5 ng/g lw, respectively. Moreover, the TDCIPP concentrations in dead embryos (70.5-216.8 ng/g lw) were much higher than those in live embryos (1.2-10.5 ng/g lw). Embryonic mortality was also observed in well-controlled laboratory experiments in which wild crucian carp were exposed to TDCIPP at concentrations similar to those measured in embryos collected from Taihu Lake, thus confirming TDCIPP as a causal factor in mass crucian carp embryo mortality in Taihu Lake. TDCIPP thus poses a threat to the sustainability of fisheries worldwide, given the high worldwide production volume of this chemical and its embryonic lethal toxicity.

Cyanobacteria blooms produce teratogenic retinoic acids.

Deformed amphibians have been observed in eutrophic habitats, and some clues point to the retinoic acids (RAs) or RA mimics. However, RAs are generally thought of as vertebrate-specific hormones, and there was no evidence that RAs exist in cyanobacteria or algae blooms. By analyzing RAs and their analogs 4-oxo-RAs in natural cyanobacteria blooms and cultures of cyanobacteria and algae, we showed that cyanobacteria blooms could produce RAs, which were powerful animal teratogens. Intracellular RAs and 4-oxo-RAs with concentrations between 0.4 and 4.2 × 10(2) ng/L were detected in all bloom materials, and extracellular concentrations measured in water from Taihu Lake, China, were as great as 2.0 × 10 ng/L, which might pose a risk to wildlife through chronic exposure. Further examination of 39 cyanobacteria and algae species revealed that 32 species could produce RAs and 4-oxo-RAs (1.6-1.4 × 10(3) ng/g dry weight), and the dominant cyanobacteria species in Taihu Lake, Microcystis flos-aquae and Microcystis aeruginosa, produced high amounts of RAs and 4-oxo-RAs with concentrations of 1.4 × 10(3) and 3.7 × 10(2) ng/g dry weight, respectively. Most genera of cyanobacteria that could produce RAs and 4-oxo-RAs, such as Microcystis, Anabaena, and Aphanizomenon, often occur dominantly in blooms. Production of RAs and 4-oxo-RAs by cyanobacteria was associated with species, origin location, and growth stage. These results represent a conclusive demonstration of endogenous production of RAs in freshwater cyanobacteria blooms. The observation of teratogenic RAs in cyanobacteria is evolutionarily and ecologically significant because RAs are vertebrate-specific hormones, and cyanobacteria form extensive and highly visible blooms in many aquatic ecosystems.

Biosensor medaka for monitoring intersex caused by estrogenic chemicals.

Estrogenic chemicals can induce intersex in fish species leading to disturbance of spermatogenesis and impairment of reproductive success. To overcome the shortcomings of conventional histopathological observation on intersex (low sensitivity, relatively poor accuracy, long experimental periods, as well as laborious and time-consuming), we generated a pMOSP1-EGFP transgenic medaka fish model. In this transgenic fish, the green fluorescence protein (GFP) reporter gene was derived by the regulatory elements of the OSP1 gene, which is a specific and sensitive molecular biomarker for indicating intersex occurrence in male medaka fish exposed to estrogenic chemicals. The transgenic GFP was faithfully expressed in ovaries and in testes with intersex, perfectly mimicking the expression pattern of endogenous OSP1. In intersex testis, the diameters of primary oocytes which could be distinguished by GFP fluorescence observation were as small as 10 µm, lower than that (more than 20 µm) which is observable by histopathology. Using the novel transgenic medaka fish, intersex was observed after 90-day exposure to 0.75 ng/L 17α-ethinyloestradiol (EE2) (0-90 dph), but only at concentrations of at least 1.38 ng/L EE2 by histopathology. An effectiveness of a short-term in vivo assay for screening estrogenic chemicals that can monitor intersex appearance at early sex developmental stage (about 30 dph) in male medaka fish was also demonstrated by assessing the intersex induction of EE2, 17ß-estradiol and 4-nonylphenol. This newly developed assay provides an enhanced ability for screening and testing estrogenic chemicals with the potential to induce intersex and studying their biological impacts.

An adaptive integral sliding mode control strategy for medical linear accelerator vacuum system.

Medical linear accelerators (MLAs) are critical components for radiation therapy, providing a state-of-the-art treatment platform for cancer therapy. The vacuum system is one of the most important MLA subsystems and its stable operation is necessary to generate high-quality beams. For vacuum system pressure control, traditional proportional-integral-derivative (PID) strategies have disadvantages such as inaccurate and imprecise control response due to its simple calculation. This paper presents an innovative adaptive integral sliding mode control (AISMC) strategy aimed at enhancing the response time, precision of control, and capability to reduce disturbances within the MLA vacuum system. In addition, a nonlinear MLA vacuum system mathematical model is established based on mechanism method. Stability of the developed vacuum control system is validated using Lyapunov stability theory. Simulation results illustrate that the proposed AISMC strategy has better response speed and accuracy than traditional PID-based systems, achieving better pressure tracking performance than traditional sliding mode control strategy with PID control. Most important for the proposed controller, system chattering is effectively mitigated.

Determination and occurrence of retinoids in a eutrophic lake (Taihu Lake, China): cyanobacteria blooms produce teratogenic retinal.

Besides retinoic acids (RAs), some retinoids such as retinal (RAL) and retinol (ROH), which are considered as RA precursors in vertebrates, are also reported to be teratogenic agents. In this study we investigated four RA precursors including RAL, ROH, retinyl palmitate, and ß-carotene in the eutrophic Taihu Lake, China, by developing a sensitive analytical method. RAL and ß-carotene were widely detected in natural cyanobacteria blooms and lake water. Intracellular concentrations of RAL and ß-carotene in blooms were 9.4 to 6.9 × 10(3) and 3.4 to 1.8 × 10(5) ng L(-1), respectively, and their concentrations in lake water were up to 1.4 × 10 ng L(-1) (RAL) and 9.8 × 10(2) ng L(-1) (ß-carotene). The good correlation between intracellular concentrations of RAL and RAs implied that RAL was involved in the production of RAs by cyanobacteria blooms. Further examination of 39 cyanobacteria and algae species revealed that most species could produce RAL and ß-carotene. The greatest amount of RAL was found in Chlamydomonas sp. (FACHB-715; 1.9 × 10(3) ng g(-1) dry weight). As the main cyanobacteria in Taihu Lake, many Microcystis species could produce high amounts of RAL and were thought to greatly contribute to the production of RAL measured in the blooms. Productions of RAL and ß-carotene by cyanobacteria were associated with species, origin location, and growth stage. The results in this study present the existence of a potential risk to aquatic animals living in a eutrophic environment from a high concentration of RAL in cyanobacteria blooms and also provide a clue for further investigating the mechanism underlying the biosynthetic pathway of RAs in cyanobacteria and algae.

CT-CBCT deformable registration using weakly-supervised artifact-suppression transfer learning network.

Objective.Computed tomography-cone-beam computed tomography (CT-CBCT) deformable registration has great potential in adaptive radiotherapy. It plays an important role in tumor tracking, secondary planning, accurate irradiation, and the protection of at-risk organs. Neural networks have been improving CT-CBCT deformable registration, and almost all registration algorithms based on neural networks rely on the gray values of both CT and CBCT. The gray value is a key factor in the loss function, parameter training, and final efficacy of the registration. Unfortunately, the scattering artifacts in CBCT affect the gray values of different pixels inconsistently. Therefore, the direct registration of the original CT-CBCT introduces artifact superposition loss.Approach. In this study, a histogram analysis method for the gray values was used. Based on an analysis of the gray value distribution characteristics of different regions in CT and CBCT, the degree of superposition of the artifact in the region of disinterest was found to be much higher than that in the region of interest. Moreover, the former was the main reason for artifact superposition loss. Consequently, a new weakly supervised two-stage transfer-learning network based on artifact suppression was proposed. The first stage was a pre-training network designed to suppress artifacts contained in the region of disinterest. The second stage was a convolutional neural network that registered the suppressed CBCT and CT.Main Results. Through a comparative test of the thoracic CT-CBCT deformable registration, whose data were collected from the Elekta XVI system, the rationality and accuracy after artifact suppression were confirmed to be significantly improved compared with the other algorithms without artifact suppression.Significance. This study proposed and verified a new deformable registration method with multi-stage neural networks, which can effectively suppress artifacts and further improve registration by incorporating a pre-training technique and an attention mechanism.

Systematic review and meta-analysis of effects of acupuncture on pain and function in non-specific low back pain.

OBJECTIVE: To assess the effectiveness of acupuncture for non-specific low back pain (NSLBP) through systematic review of published randomised controlled trials (RCTs). METHODS: Studies were identified in electronic databases from their inception to February 2018, and were grouped according to the control interventions. The outcomes of interest were pain intensity and disability. Methodological quality was evaluated using the Cochrane risk-of-bias criteria and the Standards for Reporting Interventions in Controlled Trials of Acupuncture (STRICTA) checklist. The review was reported according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. RESULTS: 25 trials (n=7587 participants) were identified and included in a meta-analysis. The results showed that acupuncture was more effective at inducing pain relief than: no treatment (standardised mean difference (SMD) -0.69, 95% CI -0.99 to -0.38); sham acupuncture in the immediate term (SMD -0.33, 95% CI -0.49 to -0.18), short term (SMD -0.47, 95% CI -0.77 to -0.17), and intermediate term (SMD -0.17, 95% CI -0.28 to -0.05); and usual care in the short term (SMD -1.07, 95% CI -1.81 to -0.33) and intermediate term (SMD -0.43, 95% CI -0.77 to -0.10). Also, adjunctive acupuncture with usual care was more effective than usual care alone at all time points studied. With regard to functional improvement, the analysis showed a significant difference between acupuncture and no treatment (SMD -0.94, 95% CI -1.57 to -0.30), whereas the other control therapies could not be assessed. CONCLUSION: We draw a cautious conclusion that acupuncture appears to be effective for NSLBP and that acupuncture may be an important supplement to usual care in the management of NSLBP.

Effects of yoga on patients with chronic nonspecific neck pain: A PRISMA systematic review and meta-analysis.

BACKGROUND: Chronic nonspecific neck pain (CNNP) has a high prevalence and is more common among younger people. Clinical practice suggests that yoga is effective in relieving chronic pain. OBJECTIVES: This meta-analysis aimed to quantitatively summarize the efficacy of yoga for treating CNNP. DATA SOURCES: We searched for trials in the electronic databases from their inception to January 2019. English databases including PubMed, MEDLINE, Cochrane Library, Embase, Scopus, the Cochrane Central Register of Controlled Trials, and Ind Med; Chinese databases including China National Knowledge Infrastructure (CNKI), WanFang Database, and VIP Information. We also conducted a manual search of key journals and the reference lists of eligible papers to identify any potentially relevant studies we may have missed. We placed no limitations on language or date of publication. STUDY ELIGIBILITY CRITERIA: We included only randomized controlled trials (RCTs) and q-RCTs evaluating the effects of yoga on patients with CNNP. The primary outcomes for this review were pain and disability, and the secondary outcomes were cervical range of motion (CROM), quality of life (QoL), and mood. PARTICIPANTS AND INTERVENTIONS: Trails that examined the clinical outcomes of yoga intervention in adults with CNNP compared with those of other therapies except yoga (e.g., exercise, pilates, usual care, et al) were included. STUDY APPRAISAL AND SYNTHESIS METHODS: Cochrane risk-of-bias criteria were used to assess the methodological quality, and RevMan 5.3 software was used to conduct the meta-analysis. RESULTS: A total of 10 trials (n = 686) comparing yoga and interventions other than yoga were included in the meta-analysis. The results show that yoga had a positive effects on neck pain intensity (total effect: SMD = -1.13, 95% CI [-1.60, -0.66], Z = 4.75, P < .00001), neck pain-related functional disability (total effect: SMD = -0.92, 95% CI [-1.38, -0.47], Z = 3.95, P < .0001), CROM (total effect: SMD = 1.22, 95% CI [0.87, 1.57], Z = 6.83, P < .00001), QoL (total effect: MD = 3.46, 95% CI [0.75, 6.16], Z = 2.51, P = .01), and mood (total effect: SMD = -0.61, 95% CI [-0.95, -0.27], Z = 3.53, P = .0004). CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS: It was difficult to make a comprehensive summary of all the evidence due to the different session and duration of the yoga interventions, and the different outcome measurement tools in the study, we draw a very cautious conclusion that yoga can relieve neck pain intensity, improve pain-related function disability, increase CROM, improve QoL, and boost mood. This suggests that yoga might be an important alternative in the treatment of CNNP. SYSTEMATIC REVIEW REGISTRATION NUMBER: Details of the protocol for this systematic review and meta-analysis were registered on PROSPERO and can be accessed at www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42018108992.

Simultaneous determination of primary and secondary phthalate monoesters in the Taihu Lake: Exploration of sources.

While phthalates monoesters have been recognized as the bioactive metabolites of phthalates, the knowledge on their environmental occurrence and sources is limited. In this study, monomethyl phthalate (MMP), monoethyl phthalate (MEP), mono-iso-butyl phthalate (MiBP), mono-n-butyl phthalate (MnBP), and mono-2-ethylhexyl phthalate (MEHP) were frequently detected in water samples from the Taihu Lake in China using an improved SPE-LC-MS-MS method. The mean concentrations for MMP, MEP, MiBP, MnBP, and MEHP were 51.7 ±â€¯25.2, 6.0 ±â€¯4.8, 19.6 ±â€¯14.6, 42.2 ±â€¯64.7, and 33.0 ±â€¯37.4 ng/L, respectively, while those of their corresponding parent chemicals, DMP, DEP, DiBP, and DnBP and DEHP, were 36.54 ±â€¯43.22, 42.64 ±â€¯66.66, 246.8 ±â€¯311.1, 524.7 ±â€¯586.9, and 208.1 ±â€¯223.5 ng/L, respectively. Three secondary monoesters of DEHP, mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono (2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono (2-ethyl-5-carboxypentyl) phthalate (MECPP) were for the first time detected with mean concentration of 1.27 ±â€¯1.33, 1.33 ±â€¯1.54, and 0.73 ±â€¯0.79 ng/L, respectively. The percentage of the sum concentration of MEOHP, MEHHP, and MECPP relative to total concentration of DEHP metabolites was 5.3-12.4%. DEHP was identified to be biodegraded into secondary phthalate monoesters in water from the Taihu Lake, but their contribution to the total concentration of DEHP metabolites was 1.2-3.6%, lower than those in the Taihu Lake. Primary and secondary DEHP monoesters were also detected in influents and effluents of two sewage treatment plants adjacent to the Taihu Lake, the percentages of secondary DEHP monoesters in influents were 5.8% and 11.3%, similar with those in the Taihu Lake. Taken together with their relatively high concentrations in influents, the discharging of domestic wastewater may be an important contributor to the occurrence of phthalate monoesters in the Taihu Lake.

Toxicity of triphenyltin on the development of retinal axons in zebrafish at low dose.

The impacts of triphenyltin (TPT) on ecological health are of particular concern due to the unexpectedly high levels found in wild fish around the world. Here, zebrafish embryos were exposed to TPT via in ovo nano-injection to study its toxicity on the development of retinal axons in fish. Lipophilic dye labeling revealed obvious defects in retinal axon development in larvae with normally shaped eyes, with incidences of 0, 1.08%, 2.66%, 4.26%, and 6.85% observed in the control, 0.8, 4.0, 20.0, and 100ng TPT-Cl/g wet weight (ww) exposure groups, respectively, showing a dose-dependent increase. Since the lowest observable effective concentration of TPT to induce retinal axon development defects was 0.8ng TPT-Cl/g ww, which is lower than the concentrations in wild fish eggs, this defect would occur in wild fish larvae. Alterations in the expressions of pax6 and ephrinBs, which regulate the establishment of retinal polarity, were correlated with defect incidence. Expression levels of the CYP26A1 gene and protein were significantly up-regulated in all exposure groups compared with the control, which may lead to significant decreases in concentrations of all-trans retinoic acid (atRA). Such a disruption of RA metabolism would, at least partly, contribute to the incidence of developmental defects in retinal axons. This study is the first to report that TPT can interfere with development of retinal axons in fish at low dose.

Chromium (VI) potentiates the DNA adducts (O(6)-methylguanine) formation of N-nitrosodimethylamine in rat: implication on carcinogenic risk.

Chromium (VI) [Cr(VI)] and nitrosamines such as N-nitrosodimethylamine (NDMA) exist commonly in the environment. To evaluate the potential influence of Cr(VI) co-exposure on the carcinogenic risk of NDMA, Female Wistar rats were treated with various concentrations of Cr(VI) and/or NDMA via drinking water for 15days and the DNA adducts (O(6)-methylguanine, O(6)-MeG) of NDMA in liver tissue was used as a bioindicator. The results showed that Cr(VI) synergistically enhanced the O(6)-MeG formation, which could lead to an increase in DNA damage and carcinogenic potential. Although Cr(VI) did not alter the CYP 2E1 enzyme activity, it decreased GSH content, which would be an potential mechanism for the potentiated O(6)-MeG formation by Cr(VI) co-exposure. These results would contribute to the development of quantitative risk assessment of NDMA or even for a group of nitrosamines under environmental mixture exposure.

Dynamic evaluation of environmental impact due to tritium accidental release from the fusion reactor.

As one of the key safety issues of fusion reactors, tritium environmental impact of fusion accidents has attracted great attention. In this work, the dynamic tritium concentrations in the air and human body were evaluated on the time scale based on accidental release scenarios under the extreme environmental conditions. The radiation dose through various exposure pathways was assessed to find out the potential relationships among them. Based on this work, the limits of HT and HTO release amount for arbitrary accidents were proposed for the fusion reactor according to dose limit of ITER. The dynamic results aim to give practical guidance for establishment of fusion emergency standard and design of fusion tritium system.