The targeting of DAPK1 with miR-190a-3p promotes autophagy in trophoblast cells.

Pre-eclampsia (PE) is a dangerous pathological status that occurs during pregnancy and is a leading reason for both maternal and fetal death. Autophagy is necessary for cellular survival in the face of environmental stress as well as cellular homeostasis and energy management. Aberrant microRNA (miRNA) expression is crucial in the pathophysiology of PE. Although studies have shown that miRNA (miR)-190a-3p function is tissue-specific, the precise involvement of miR-190a-3p in PE has yet to be determined. We discovered that miR-190a-3p was significantly lower and death-associated protein kinase 1 (DAPK1) was significantly higher in PE placental tissues compared to normal tissues, which is consistent with the results in cells. The luciferase analyses demonstrated the target-regulatory relationship between miR-190a-3p and DAPK1. The inhibitory effect of miR-190a-3p on autophagy was reversed by co-transfection of si-DAPK1 and miR-190a-3p inhibitors. Thus, our data indicate that the hypoxia-dependent miR-190a-3p/DAPK1 regulatory pathway is implicated in the development and progression of PE by promoting autophagy in trophoblast cells.

Effects of prehospital management in out-of-hospital cardiac arrest: advanced airway and adrenaline administration.

BACKGROUND: There is uncertainty about the best approaches for advanced airway management (AAM) and the effectiveness of adrenaline treatments in Out-of-hospital cardiac arrest (OHCA). This study aimed to evaluate whether AAM and adrenaline administration provided by Emergency Medical Service (EMS) can improve the outcomes of OHCA. METHODS: This study was a prospective analysis of collected data based on OHCA adult patients treated by the EMS in China from January 2019 to December 2020.The patients were divided into AAM group and no AAM group, and into subgroups according to whether adrenaline was used. The outcome was rate of return of spontaneous circulation (ROSC), survival to admission and hospital discharge. RESULTS: 1533 OHCA patients were reported. The probability of ROSC outcome and survival admission in the AAM group was significantly higher, compared with no AAM group. The probability of ROSC outcome in the AAM group increased by 66% (adjusted OR: 1.66, 95%CI, 1.02-2.71). There were no significant differences in outcomes between the adrenaline and no adrenaline groups. The combined treatment of AAM and adrenaline increased the probability of ROSC outcome by 114% (adjusted OR, 2.14, 95%CI, 1.20-3.81) and the probability of survival to admission increased by 115% (adjusted OR, 2.15, 95%CI, 1.16-3.97). CONCLUSIONS: The prehospital AAM and the combined treatment of AAM and adrenaline in OHCA patients are both associated with an increased rate of ROSC. The combined treatment of AAM and adrenaline can improve rate of survival to admission in OHCA patients.

[Simultaneous determination of four anthraquinones in Polygonum multiflorum by QAMS].

A simple, specific and selective quantitative analysis of multi-components by single marker(QAMS) method for simultaneous determination of anthraquinones and anthraquinone glycosides in Polygonum multiflorum was developed. Four main anthraquinones and its glycosides, emodin, emodin-8-O-ß-D-glucoside, physcion and physcion-8-O-ß-D-glucoside were selected as analytes to evaluate the quality of P. multiflorum. Emodin was used as the internal standard, and the relative correction factors(RCFs) between emodin and the other three anthraquinones were calculated. Comparison of the contents of the four components in 30 batches of P. multiflorum from different regions and 12 batches decoction pieces from different manufacturers by QAMS and external standard method(ESM) showed that there was no significant difference between QAMS and ESM for quantification of the four main components by using relative error results, and the QAMS method was accurate and reliable, and had a good repeatability. In addition, compared with the results calculated by the difference method between total anthraquinone and free anthraquinone in the content determination of P. multiflorum in Chinese Pharmacopoeia, the results of direct determination combined anthraquinone by QAMS were very close to that by measured the external standard method. Therefore, simultaneous quantification of four main anthraquinones by using QAMS is suitable to evaluate the quality of P. multiflorum. Then the optimized assay method of the combined anthraquinone contents showed simple and feasible, which could be replaced and improved the quantification method of the combined anthraquinone in the current Chinese Pharmacopeia.

Systematic review and meta-analysis found higher levels of behavioural problems in male left-behind children aged 6-11 years.

AIM: Left-behind children (LBC) now account for more than 1 in 5 Chinese children, and they often suffer from behavioural problems when their parents leave their rural homes to seek work in urban areas. The primary aim of this meta-analysis was to compare the incidence rates and factor scores of behavioural problems in LBC, who now account for more than one-fifth of Chinese children, and non-LBC. METHODS: This systematic review and meta-analysis explored the children's characteristic behavioural problems using the Achenbach Child Behaviour Check List. A subgroup analysis was conducted to compare the different behavioural problems of LBC with different characteristics. The meta-analysis assessed 1405 papers and analysed 13 papers from 2007 to 2015, covering 10 264 LBC and 8909 non-LBC from 2 to 19 years of age. RESULTS: The incidence rates of behavioural problems were higher in LBC than non-LBC. The highest risks were noted in boys aged between 6 and 11 years of age, who were more likely to be withdrawn and be affected by somatic complaints, schizophreniform disorder, compulsive behaviour and depression. CONCLUSION: Interventions and policies are urgently needed to tackle behavioural issues among LBC, especially high-risk males aged 6-11 years.

Serosurvey of Avian metapneumovirus, Orithobacterium rhinotracheale, and Chlamydia psittaci and Their Potential Association with Avian Airsacculitis.

Seasonal outbreaks of airsacculitis in China's poultry cause great economic losses annually. This study tried to unveil the potential role of Avian metapneumovirus (AMPV), Ornithobacterium rhinotracheale (ORT) and Chlamydia psittaci (CPS) in avian airsacculitis. A serological investigation of 673 breeder chickens and a case-controlled study of 430 birds were undertaken. Results showed that infection with AMPV, ORT, and CPS was highly associated with the disease. The correlation between AMPV and CPS were positively robust in both layers and broilers. Finally, we determined the co-infection with AMPV, ORT, and CPS was prevalent in the sampled poultry farms suffering from respiratory diseases and the outbreak of airsacculitis was closely related to simultaneous exposure to all three agents.

Mutual detoxification of mercury and selenium in unicellular Tetrahymena.

Selenium (Se) is commonly recognized as a protective element with an antagonistic effect against mercury (Hg) toxicity. However, the mechanisms of this Hg-Se antagonism are complex and remain controversial. To gain insight into the Hg-Se antagonism, a type of unicellular eukaryotic protozoa (Tetrahymena malaccensis, T. malaccensis) was selected and individually or jointly exposed to two Hg and three Se species. We found that Se species showed different toxic effects on the proliferation of T. malaccensis with the toxicity following the order: selenite (Se(IV))>selenomethionine (SeMeth)>selenate (Se(VI)). The Hg-Se antagonism in Tetrahymena was observed because the joint toxicity significantly decreased under co-exposure to highly toxic dosages of Hg and Se versus individual toxicity. Unlike Se(IV) and Se(VI), non-toxic dosage of SeMeth significantly decreased the Hg toxicity, revealing the influence of the Se species and dosages on the Hg-Se antagonism. Unexpectedly, inorganic divalent Hg (Hg2+) and monomethylmercury (MeHg) also displayed detoxification towards extremely highly toxic dosages of Se, although their detoxifying efficiency was discrepant. These results suggested mutual Hg-Se detoxification in T. malaccensis, which was highly dependent on the dosages and species of both elements. As compared to other species, SeMeth and MeHg promoted the Hg-Se joint effects to a higher degree. Additionally, the Hg contents decreased for all the Hg-Se co-exposed groups, revealing a sequestering effect of Se towards Hg in T. malaccensis.

Tetrabromobisphenol-A/S and Nine Novel Analogs in Biological Samples from the Chinese Bohai Sea: Implications for Trophic Transfer.

Tetrabromobisphenol-A/S (TBBPA/S) analogs have raised substantial concern because of their adverse effects and potential bioaccumulative properties, such as TBBPA bis(allyl ether) (TBBPA-BAE) and TBBPA bis(2,3-dibromopropyl ether) (TBBPA-BDBPE). In this study, a comprehensive method for simultaneous determination of TBBPA/S and nine novel analogs, including TBBPA-BAE, TBBPA-BDBPE, TBBPS-BDBPE, TBBPA mono(allyl ether) (TBBPA-MAE), TBBPA mono(2-bromoallyl ether) (TBBPA-MBAE), TBBPA mono(2,3-dibromopropyl ether) (TBBPA-MDBPE), TBBPS-MAE, TBBPS-MBAE, and TBBPS-MDBPE in biological samples was developed. The distribution patterns and trophic transfer properties of TBBPA/S and analogs in various biological samples collected from the Chinese Bohai Sea were then studied in detail. For the first time, TBBPA-MBAE and TBBPS-BDBPE were detected in biological samples and TBBPA-MBAE was identified as a byproduct. The concentrations of TBBPA and analogs ranged from ND (not detected or below the method detection limit) to 2782.8 ng/g lipid weight (lw), and for TBBPS and analogs ranged from ND to 927.8 ng/g lw. High detection frequencies (>86%) for TBBPA, TBBPS and TBBPA-MAE, TBBPA-MDBPE, TBBPS-MAE, TBBPS-MBAE, and TBBPS-MDBPE were obtained. Meanwhile, TBBPA, TBBPS, and these five analogs displayed trophic dilution tendencies due to significantly negative correlations between trophic levels and lipid-corrected concentrations together with the trophic magnification factors (from 0.31 to 0.55). The results also indicated the novel TBBPA-MAE, TBBPA-MBAE, TBBPA-MDBPE, TBBPS-MAE, TBBPS-MBAE, and TBBPS-MDBPE could be generated not only as byproducts, but also as the probable transformation products of commercial TBBPA/S derivatives.

Small object intelligent detection method based on adaptive recursive feature pyramid.

As we all know, YOLOv4 can achieve excellent detection performance in object detection and has been effectively applied in many fields. However, the inconsistency of scale features affects the prediction accuracy of the path aggregation network (PANet) in YOLOv4 for small objects, resulting in low detection accuracy. This paper presents YOLOv4, which uses an adaptive recursive path aggregation network (AR-PANet) to improve the detection accuracy of small objects. First, the output characteristics of the PANet are fed back into the backbone network by using a recursive structure to enrich the characteristic information of the object. Second, an adaptive approach is developed to eliminate conflicting information in multi-scale feature space, thereby enhancing scale invariance and promoting feature extraction accuracy for small objects. Finally, the CBAM is used to map the multi-scale features obtained from the AR-PANet to independent channels and spatial dimensions to achieve feature refinement, thus improving the detection accuracy of small objects. Experimental results show that our proposed method can effectively improve the accuracy of small object detection in multiple datasets, addressing this challenging problem with impressive results. Thus, our proposed approach has great potential and valuable applications in the fields of remote sensing and intelligent transportation.

[Expression profiles of IL-10, TNF-a, and SOCS3 in placenta of pregnant women with intrahepatic cholestasis].

OBJECTIVE: To detect the expression profiles of suppressor of cytokine signaling 3 (SOCS3), interleukin (IL)-10, and tumor necrosis factor-alpha (TNF-a) in the placenta of women with intrahepatic cholestasis of pregnancy (ICP) and determine the clinical significance of the differential expressions. METHODS: Placentas were collected from 37 ICP gravidas who delivered through cesarean section at the First Teaching Hospital of Xingjiang Medical University from October 2010 to May 2011 and from 35 healthy pregnant women (controls). SOCS3, TNF-a, and IL-10 protein levels were detected by immunoblotting and the Envision immunohistochemical method. RESULTS: TNF-a and IL-10 expression was detected in placentas of both groups, and was present mainly in the cytoplasm of trophoeytes. IL-10 expression was obviously lower in the ICP placentas than in the control placentas; meanwhile, TNF-a expression was obviously higher than in the control placentas (Z=-2.63, P less than 0.01). SOCS3 protein was significantly more abundant in the control placentas than in the ICP placentas. Furthermore, SOCS3 and IL-10 placental expressions were positively correlated (r=0.494, P less than 0.01), but there was a negative correlation between SOCS3 and TNF-a placental expressions (r=-0.472, P less than 0.01). CONCLUSION: In ICP, an increase of the type 1 cytokine, TNF-a, is associated with decreases of the type 2 cytokine, IL-10, and of SOCS3, which may reduce the secretion of IL-10. Furthermore, SOCS3 may contribute to ICP pathogenesis by modulating the Th1/Th2 cytokine balance.

Functional mechanism and clinical implications of miR-141 in human cancers.

Cancer is caused by the abnormal proliferation of local tissue cells under the control of many oncogenic factors. MicroRNAs (miRNAs) are a class of evolutionarily conserved, approximately 22-nucleotide noncoding small RNAs that influence transcriptional regulationby binding to the 3'-untranslated region of target messenger RNA. As a member of the miRNA family, miR-141 acts as a suppressor or an oncomiR in various cancers and regulates cancer cell proliferation, apoptosis, invasion, and metastasis through a variety of signaling pathways, such as phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) and constitutive activation of nuclear factor-κB (NF-κB). Target gene validation and pathway analysis have provided mechanistic insight into the role of this miRNA in different tissues. This review also outlines novel findings that suggest miR-141 may be useful as a noninvasive biomarker and as a therapeutic target in several cancers.

[Pollution Characterization, Source Identification, and Health Risks of Atmospheric Particle-Bound Heavy Metals in PM2.5 in Zhengzhou City: Based on High-resolution Data].

In order to study the pollution characteristics and sources of heavy metals in urban atmospheric PM2.5, 21 elements in atmospheric PM2.5 in Zhengzhou City were detected using an online metal analyzer during July and October 2017 and January and April 2018, and the changes in heavy metal concentrations were analyzed. Heavy metals were traced by enrichment factors, principal component analysis, and potential source function. The US EPA risk assessment model was used to assess their health risks. The results showed that:the concentrations of K, Zn, Mn, Pb, Cu, As, Cr, and Se increased with the increase in pollution level. The results of enrichment factors and principal component analysis showed that the main sources of heavy metals were crust, mixed combustion, industry, and motor vehicles. The characteristic radar charts showed that the pollution dominated by crustal sources mainly occurred in spring and winter, whereas the pollution dominated by mixed combustion sources mainly occurred in winter. Pb, As, and Ni were greatly affected by the transport of a fen nutrient-laden plain, Beijing-Tianjin-Hebei, and southern Henan, whereas Cd was greatly affected by the northwest region of the sampling site. As presented a significant carcinogenic risk in both adults and children, whereas Pb and Sb presented a significant non-carcinogenic risk in children.

Undetectable transcription of cap in a clinical AAV vector: implications for preformed capsid in immune responses.

In a gene therapy clinical trial for hemophilia B, adeno-associated virus 2 (AAV2) capsid-specific CD8(+) T cells were previously implicated in the elimination of vector-transduced hepatocytes, resulting in loss of human factor IX (hFIX) transgene expression. To test the hypothesis that expression of AAV2 cap DNA impurities in the AAV2-hFIX vector was the source of epitopes presented on transduced cells, transcription of cap was assessed by quantitative reverse transcription-PCR (Q-RT-PCR) following transduction of target cells with the vector used in the clinical trial. Transcriptional profiling was also performed for residual Amp(R), and adenovirus E2A and E4. Although trace amounts of DNA impurities were present in the clinical vector, transcription of these sequences was not detected after transduction of human hepatocytes, nor in mice administered a dose 26-fold above the highest dose administered in the clinical study. Two methods used to minimize encapsidated DNA impurities in the clinical vector were: (i) a vector (cis) production plasmid with a backbone exceeding the packaging limit of AAV; and (ii) a vector purification step that achieved separation of the vector from vector-related impurities (e.g., empty capsids). In conclusion, residual cap expression was undetectable following transduction with AAV2-hFIX clinical vectors. Preformed capsid protein is implicated as the source of epitopes recognized by CD8(+) T cells that eliminated vector-transduced cells in the clinical study.

Reversal of blindness in animal models of leber congenital amaurosis using optimized AAV2-mediated gene transfer.

We evaluated the safety and efficacy of an optimized adeno-associated virus (AAV; AAV2.RPE65) in animal models of the RPE65 form of Leber congenital amaurosis (LCA). Protein expression was optimized by addition of a modified Kozak sequence at the translational start site of hRPE65. Modifications in AAV production and delivery included use of a long stuffer sequence to prevent reverse packaging from the AAV inverted-terminal repeats, and co-injection with a surfactant. The latter allows consistent and predictable delivery of a given dose of vector. We observed improved electroretinograms (ERGs) and visual acuity in Rpe65 mutant mice. This has not been reported previously using AAV2 vectors. Subretinal delivery of 8.25 x 10(10) vector genomes in affected dogs was well tolerated both locally and systemically, and treated animals showed improved visual behavior and pupillary responses, and reduced nystagmus within 2 weeks of injection. ERG responses confirmed the reversal of visual deficit. Immunohistochemistry confirmed transduction of retinal pigment epithelium cells and there was minimal toxicity to the retina as judged by histopathologic analysis. The data demonstrate that AAV2.RPE65 delivers the RPE65 transgene efficiently and quickly to the appropriate target cells in vivo in animal models. This vector holds great promise for treatment of LCA due to RPE65 mutations.

Reduced expression of the lncRNA NRON is a potential hallmark of the CMV-amplified CD8+ T cell accumulations commonly seen in older humans.

The characteristic accumulation of late-stage differentiated CD8+ T cells is enhanced by lifelong latent cytomegalovirus (CMV) persistence, which makes it challenging to screen for subclinical biomarkers of immune aging in the elderly. We systematically identified predominantly preformed, long, noncoding RNAs (lncRNAs) as integrative biomarkers of CD8+ T cell aging in 14 elderly CMV carriers over 80 years of age. After sorting the CD28nullCD8+ T cell subset and its CD28bearingCD8+ counterpart in five nonagenarians, we profiled the differential expression of lncRNAs and genes in CD28nullCD8+ T cells via array detection. We focused on 11 differentially expressed antisense lncRNAs and cross-referenced them with previously identified age-accumulated lncRNAs to create a set of candidates in CD28nullCD8+T cells. We performed intracellular validation on the age-accumulated candidate lncRNAs paired with their antisense target genes using quantitative polymerase chain reaction (qPCR). Simultaneously, we sorted the CMVpp65-specific CD8+ T cell subset and its counterpart from participant cells with the HLA-A-*0201 genotype. The validated age-accumulated lncRNAs in CD28nullCD8+ T cells were intracellularly cross-validated in CMVpp65CD8+ T cells. Finally, we identified the immunity-related gene(s) that acted as potential target(s) to the cross-validated age-accumulated lncRNA(s), using bioinformatics techniques. The potential regulation of the final identified lncRNA-gene pair(s) was simultaneously predicted in two pathway-integrated networks. We concluded that expression of an age-accumulated lncRNA (NRON) was decreased, whereas that of its immunity-related target gene (NFAT) was increased, in both CD28nullCD8+ T cells and CMVpp65CD8+ T cells of elderly individuals with persistent CMV infection. The identification of NRON as a potential biomarker suggests that NRON contributes to CMV-enhanced CD28nullCD8+ T cell aging by modulating phosphorylation and/or IL-4-dependent NFAT signaling.

Use of a Modified DANP-mV Model to Improve Quality of Life in Rural Residents: The Empirical Case of Xingshisi Village, China.

Climate change-related anomalies have increased public concern regarding environmental protection. This has opened newer rural development avenues. In this regard, livability of villages is crucial; it can be evaluated based on the villagers' quality of life (QoL). The WHOQOL-BREF, a comprehensive cross-cultural and cross-disciplinary scale proposed by the World Health Organization to assess QoL, has aided in assessing and improving QoL in different regions. However, the factors of this instrument are mutually influential, necessitating an improvement strategy considering the entire system. This problem may be resolved using the DANP-mV model. However, the traditional DANP-mV model includes many items and responding to all of them is difficult for experts. Therefore, by using the case of Xingshisi Village in China, this study proposed a modified DANP-mV model to provide additional suggestions for systematic improvement of the QoL and livability in the village. Xingshisi is a model village built according to an aspirational benchmark; however, different from the traditional definition of a benchmark, this village exhibits room for improvement. Although the modified model reduces the number of questions from 650 to 168, its effect remains similar to that of the traditional model. Moreover, in the modified model, physical capacity (D1) presented the largest dimensional gap. The interaction among the factors indicated that considering the effect of the environment (D4) and developing a systematic improvement strategy are necessary to improve the livability of villages facing limited resources.

Chemical profiles and metabolite study of raw and processed Polygoni Multiflori Radix in rats by UPLC-LTQ-Orbitrap MSn spectrometry.

The raw and processed roots of Plygonum multiflorum Thunb (PM) are used to treat different diseases in clinical practice. In order to clarify the influence of processing, a comparative study of chemical substance analysis was carried out. As the xenobiotics with a high enough exposure in target organs being considered as the potential effective or toxicity components, an in vivo study was also implemented to characterize the constitutes and metabolites, and meanwhile, the factor of compatibility with black bean were also considered. As a result, a total of 148 compounds were detected in PM extracts and more than 40 compounds were only detected in the processed products, which were probably new components produced during the steaming process. In in vivo study, 7 prototype components and 66 metabolites were detected or tentatively identified, 24 of which were reported for the first time. Our results indicated that processing greatly changed the chemical composition of PM and influenced the disposition of the compounds in vivo. To the best of our knowledge, this was the first global comparative study of raw and processed PM. These results expanded our knowledge about the influence of processing of PM and provided the essential data for further efficacy or toxicity studies.

Separation of adeno-associated virus type 2 empty particles from genome containing vectors by anion-exchange column chromatography.

Adeno-associated virus (AAV) empty capsids typically co-purify with genome containing AAV2 vectors purified by column chromatography. This study describes a method to remove empty capsids from genome containing vector particles by anion exchange chromatography. The separation is based on the slightly less anionic character of empty particles compared to vectors. Detailed methods to achieve AAV2 vector purification and particle separation using cation exchange resin POROS 50HS followed by anion exchange resin Q-Sepharose(xl) are described. Chromatographic separation of AAV2 particles was achieved using gradients based on sodium acetate and ammonium acetate, and was optimal at pH 8.5. Efficient removal of particle surface nucleic acid impurities was found to be important to achieve good particle separation. In a large scale experiment performed using partially purified vector containing a mixture of 1.56 x 10(14)vg and 2.52 x 10(15) empty capsids as a starting material, the optimized anion exchange chromatography method resulted in a vector peak of 1.15 x 10(14)vg containing 0.25 x 10(14) empty capsids, corresponding to 74% vector yield and 86-fold reduction in empty capsids in the vector product.

The association between vitamin D level and diabetic peripheral neuropathy in patients with type 2 diabetes mellitus: An update systematic review and meta-analysis.

AIM: Recently, increasing studies have been carried out to explore the association between vitamin D level and the development of diabetic peripheral neuropathy (DPN) in patients with diabetes mellitus (DM). However, because of the shortcoming in study design and sample size, there is still no clear conclusion. We performed this meta-analysis to examine the exact impact of vitamin D deficiency on DPN in type 2 diabetic patients. METHODS: Various databases were searched to identify the potential articles which explored the association between vitamin D level and diabetic peripheral neuropathy in type 2 diabetes. We pooled OR to assess the correlation between vitamin D deficiency and DPN using the random-effects model. The standardized mean difference (SMD) with 95% CI of vitamin D was also calculated to evaluate the vitamin D level between DPN and non DPN in T2DM. RESULTS: There was obvious heterogeneity in those included ten studies (I2 = 94.1%, Cochran Q test P < 0.001) using mean and standard deviation (SD) of vitamin D level. In Caucasian, vitamin D level was significantly lower in DPN patients compared with diabetic patients without DPN (SMD = -0.56, I2 = 16.9%). In Asian, the pooled OR value of vitamin D deficiency was 1.22 (95%CI: 1.17-1.27). Sensitivity analysis showed one study had great influence on this meta-analysis and it still existed after excluded that one. There was no evidence of public bias in meta analysis as showed in Begg test and Egger test. CONCLUSION: This meta-analysis indicates that vitamin D deficiency is associated with the generation and development of DPN in Caucasian with T2DM, and in Asian, diabetic patients with vitamin D deficiency are 1.22 times to suffer from DPN compared with normal vitamin D level. Vitamin D supplementation is urgently needed to prevent the development of DPN in T2DM.

Distinct toxicological characteristics and mechanisms of Hg2+ and MeHg in Tetrahymena under low concentration exposure.

Inorganic divalent mercury complexes (Hg2+) and monomethylmercury complexes (MeHg) are the main mercury species in aquatic systems and their toxicity to aquatic organisms is of great concern. Tetrahymena is a type of unicellular eukaryotic protozoa located at the bottom of food chain that plays a fundamental role in the biomagnification of mercury. In this work, the dynamic accumulation properties, toxicological characteristics and mechanisms of Hg2+ and MeHg in five Tetrahymena species were evaluated in detail. The results showed that both Hg2+ and MeHg were ingested and exhibited inhibitory effects on the proliferation or survival of Tetrahymena species. However, the ingestion rate of MeHg was significantly higher than that of Hg2+. The mechanisms responsible for the toxicity of MeHg and Hg2+ were different, although both chemicals altered mitochondrial membrane potential (MMP). MeHg disrupted the integrity of membranes while Hg2+ had detrimental effects on Tetrahymena as a result of the increased generation of reactive oxygen species (ROS). In addition, the five Tetrahymena species showed different capacities in accumulating Hg2+ and MeHg, with T. corlissi exhibiting the highest accumulations. The study also found significant growth-promoting effect on T. corlissi under low concentration exposure (0.003 and 0.01µg Hg/mL (15 and 50nM)), suggesting different effect and mechanism that should be more closely examined when assessing the bioaccumulation and toxicity of mercury in aquatic ecosystems.

Synthesis of single-crystal low-loss LiB3O5 nanowire and its optical properties.

Optical-quality single-crystal LiB3O5 (LBO) nanowires are synthesized for the first time using a sol-gel method. The LBO nanowires possess diameters ranging from 200 to 800 nm and lengths of up to 200 µm, and exhibit excellent uniformity, smooth surfaces, and good mechanical properties. A typical propagating loss of 0.038 dB/µm at 532 nm is obtained for a 620 nm-diameter nanowire. This is a decrease of one order of magnitude compared with that of a ß-BaB2O4 (BBO) nanowire with similar diameter, which makes the LBO nanowire a promising candidate to construct miniaturized nonlinear photonic devices.