Distribution, seasonal variation and influencing factors of total dissolved inorganic arsenic in the middle and lower reaches of the Yellow River.

The concentrations of dissolved arsenate in natural water has an important impact on human health. The distributions, seasonal variation and major influencing factors of total dissolved inorganic arsenic (TDIAs) were studied in the Yellow River. The concentrations of TDIAs in the middle and lower reaches of the Yellow River ranged from 4.3 to 42.4 nmol/L, which met the standards for drinking water of WHO. The seasonal variation of TDIAs concentration in the middle and lower reaches of the Yellow River was highest in summer, followed by autumn and winter, and lowest in spring. The influencing factors of TDIAs concentration in the middle and lower reaches of the Yellow River mainly include the hydrological conditions, topographical variation, the adsorption and desorption of suspended particulate matter (SPM) and the intervention of human activities. The absorption of TDIAs by phytoplankton in the Xiaolangdi Reservoir (XLD) is an important factor affecting its distributions and seasonal variation. The annual flux of TDIAs transported from the Yellow River into the Bohai Sea ranged from 1.1 × 105 to 4.5 × 105 mol from 2016 to 2018, which is lower than the flux in 1985 and 2009. The carcinogenic risks (CR) of TDIAs for children and adults were all within acceptable levels (<10-6).

[Retracted] Clinical significance of miR­1298 in cervical cancer and its biological function in vitro.

[This retracts the article DOI: 10.3892/ol.2021.12662.].

Transport Property of Wrinkled Graphene Nanoribbon Tuned by Spin-Polarized Gate Made of Vanadium-Benzene Nanowire.

A series of four-terminal V7(Bz)8-WGNR devices were established with wrinkled graphene nanoribbon (WGNR) and vanadium-benzene nanowire (V7(Bz)8). The spin-polarized V7(Bz)8 as the gate channel was placed crossing the plane, the concave (endo-positioned) and the convex (endo-positioned) surface of WGNR with different curvatures via Van der Waals interaction. The density functional theory (DFT) and nonequilibrium Green's function (NEGF) methods were adopted to calculate the transport properties of these devices at various bias voltages (VS) and gate voltages (VG), such as the conductance, spin-polarized currents, transmission spectra (TS), local density of states (LDOS), and scattering states. The results indicate that the position of V7(Bz)8 and the bending curvature of WGNR play important roles in tuning the transport properties of these four-terminal devices. A spin-polarized transport property is induced for these four-terminal devices by the spin-polarized nature of V7(Bz)8. Particularly, the down-spin channel disturbs strongly on the source-to-drain conductance of WGNR when V7(Bz)8 is endo-positioned crossing the WGNR. Our findings on the novel property of four-terminal V7(Bz)8-WGNR devices provide useful guidelines for achieving flexible graphene-based electronic nanodevices by attaching other similar multidecker metal-arene nanowires.

Proton exchange rate of chemical exchange saturation transfer MRI constructed from direct saturation-removed omega plots to improve the assessment of patients with ischemic stroke.

Background: Proton exchange rate (k ex) magnetic resonance imaging (MRI) has recently been developed, with preliminary results demonstrating its potential for evaluating reactive oxygen species. This prospective cohort study investigated the k ex in different stroke stages and its correlation with stroke severity and prognosis. Methods: In all, 96 ischemic stroke patients were included in the study. Patients were divided into 3 groups based on stroke phase (acute, subacute, and chronic). A spin echo-echo planar imaging sequence with presaturation powers of 1.5, 2.5, and 3.5 µT was implemented to obtain Z-spectra, and k ex maps were constructed from direct saturation-removed omega plots. Relative k ex (rk ex) and the relative apparent diffusion coefficient (rADC) were calculated as the ratio of k ex or ADC in the infarcts to values in contralateral tissue, respectively. Correlations between both k ex and rk ex and National Institute of Health Stroke Scale (NIHSS) scores were evaluated. Receiver operating characteristic (ROC) analysis was used to evaluate the performance of k ex, rk ex, rADC, and lesion volume for predicting acute stroke outcome. Results: The k ex was significantly higher in ischemic lesions than in contralateral tissue at all stages. In addition, the k ex of acute lesions was higher than that of subacute and chronic lesions [mean (± SD) 935.1±81.5 vs. 881.4±55.7 and 866.9±76.7 s-1, respectively; P<0.05 and P<0.01, respectively]. The difference in k ex between subacute and chronic lesions was not significant. In acute stroke, there was a limited correlation between a lesion's k ex and NIHSS score (R2=0.16; P=0.01) and between rk ex and NIHSS score (R2=0.28; P=0.001). Acute stroke patients with poor prognosis had significantly higher lesion k ex and rk ex than did those with good prognosis (k ex: 991.1±78.2 vs. 893.1±55.1 s-1, P<0.001; rk ex: 1.28±0.09 vs. 1.15±0.06, P<0.001). In ROC analyses, k ex and rk ex showed favorable predictive performance for acute stroke outcome, with areas under the curve (AUC) of 0.837 and 0.880, respectively, which were slightly but not significantly higher than the AUCs for lesion volume (0.730) and rADC (0.673). Conclusions: This study indicates that k ex MRI is promising for the diagnosis and management of ischemic stroke because it can reflect the oxidative stress of lesions and predict prognosis.

Integrating ferromagnetism and ferroelectricity in an iron chalcogenide monolayer: a first-principles study.

Two-dimensional (2D) ferro-type materials have received great attention owing to the remarkable polarization effect in optoelectronics and spintronics. Using the first-principles method, the coupling between ferromagnetism and ferroelectricity is investigated in a multiferroic Janus 1T-FeSSe monolayer, which has a strong Stoner ferromagnetic ground state. The magnetic anisotropy energy (MAE) is apparently impacted by the out-of-plane asymmetry donated ferroelectricity, which is reflected by the asymmetry of the Z-MAE image. The easy magnetization axis of Janus FeSSe is the +y axis with a large MAE of 0.59 meV, rooting in unpaired d electrons of Fe atoms. The transformation of band splitting and Fermi surface can be effectively engineered by different magnetic polarization directions. The ferromagnetic (FM) coupling of the FeSSe monolayer is very robust under external strain within the range of -6% to 6%, while the strength of magnetic moment of Fe atoms and polarization are easily strain-engineered, the intrinsic mechanism of which can be elaborated by the GKA rules that depend on angles and distances. This multiferroic FeSSe monolayer provides a new platform for exploring the coupling of 2D ferromagnetism and ferroelectricity and designing low-dimensional multiferroic electronics.

G-CSF promotes the viability and angiogenesis of injured liver via direct effects on the liver cells.

BACKGROUND: Presently, liver transplantation is the only treatment strategy for liver failure (LF). Although granulocyte-colony stimulating factor (G-CSF) exhibits protective functions in LF, it is not clear whether it directly affects the liver cells. METHODS AND RESULTS: We established an injured liver cell model and observed that G-CSF treatment promoted cell viability and enhanced Ki67 and VEGF-A expression. Thereafter, human umbilical vein endothelial cells (HUVECs) were cultured in a conditioned medium collected from the G-CSF-treated injured liver cells. HUVECs' proliferation and tubule formation were promoted. Furthermore, in an injured liver mouse model, confirmed via haematoxylin-eosin staining, we evaluated serum alanine aminotransferase activity, Ki67 expression, and microvessel density (MVD). G-CSF treatment significantly relieved liver injury, upregulated Ki67 expression, and enhanced MVD in the injured mouse liver tissue. Additionally, AKT and ERK signal targets were explored, and it was demonstrated that the effects of G-CSF on injured liver cells were mediated through the AKT and ERK signalling pathways. CONCLUSIONS: G-CSF promotes injured liver viability and angiogenesis by directly affecting injured liver cells via the AKT and ERK signalling pathways. These findings improve our understanding of the role of G-CSF in recovery from LF.

Experience-dependent associations between distinct subtypes of childhood trauma and brain function and architecture.

BACKGROUND: Childhood trauma can alter brain-development trajectories and lead to a greater risk of psychopathology developing in adulthood. For this reason, understanding experience-dependent brain abnormalities associated with different trauma subtypes is crucial for identifying developmental processes disrupted by unfavorable early environments and for proposing early intervention measures to reduce trauma's negative effects. METHODS: This study used multimodal magnetic resonance imaging (MRI) to explore the neural correlates of distinct subtypes of childhood trauma. We recruited a large community sample of young adults (mean age, 24.1, SD 1.9 years) who completed a Childhood Trauma Questionnaire, were given behavioral scores, and underwent multimodal MRI. To quantify brain changes, we used functional connectivity density (FCD) mapping based on whole brain analysis, regions of interest (ROI) analysis, and morphological measurements. Experience-dependent brain abnormalities were identified by multivariable linear regression. RESULTS: We found that diverse brain regions in the FCD mapping were significantly related to 4 trauma subtypes and belonged to different cognitive components used for various behaviors. Experience-related influences on functional circuits and brain morphology were observed in extensive regions, including the sensorimotor, cingulum, accumbens, insula, and frontal-parietal areas, as well as in regions within the default mode network. CONCLUSIONS: Identifying specific regions or systems may be a valid strategy for understanding the pathogenesis and development process of psychiatric disorders in people with different traumatic experiences and may facilitate better-targeted intervention strategies for maltreated children.

Monoexponential, biexponential and stretched exponential models of diffusion weighted magnetic resonance imaging in glioma in relation to histopathologic grade and Ki-67 labeling index using high B values.

PURPOSE: To explore the performance of various parameters obtained from monoexponential (Gaussian), biexponential and stretched exponential (non-Gaussian) models of Diffusion Weighted Magnetic Resonance Imaging in differentiating gliomas with correlation to histopathology and Ki-67 labeling index (LI). MATERIALS AND METHODS: This Institute Review Board approved retrospective study included 51 pathologically proven glioma patients (WHO Grade I, n = 1; Grade II, n = 19, Grade III, n = 12; Grade IV, n = 19), and immunohistochemistry for Ki-67 LI was obtained. The conventional Magnetic Resonance (MR) images and Diffusion Weighted (DW) images with 19 non-zero b values (0-4500 s/mm2) followed by contrast-enhanced MR images were obtained at 3T preoperatively. All images were processed with Advantage Workstation 4.5 (GE Medical Systems). Region of interest (ROI) in the solid part of the tumor was manually drawn along the border meticulously excluding areas of edema, cyst, hemorrhage, necrosis, and/or calcification, and the parameters: Apparent Diffusion Coefficient (ADC) of monoexponential; pure molecular diffusion coefficient (Dslow), pseudo-diffusion coefficient (Dfast), and perfusion fraction (f) of biexponential; Distributed Diffusion Coefficient (DDC), and heterogeneity index (α) of stretched exponential models were obtained. ROI of 50 mm2 in the contralateral normal appearing white matter (NAWM) was drawn for the internal control either on centrum semiovale or white matter of the frontal lobe. Analysis of reliability by Intra-class Correlation Coefficient (ICC); correlation with Ki-67 LI by Spearman's rank correlation; comparison between high grade glioma (HGG) and low grade glioma (LGG) by either Mann Whitney U test or Independent t-Test; comparison among Grade II, III and IV gliomas by one-way ANOVA with Bonferroni; and diagnostic performance by analysis of Area Under Receiver Operating Characteristic (ROC) Curve (AUC) were conducted. RESULTS: Highly significant differences were found between HGG and LGG for all the parameters (P < 0.001 for all). In differentiating HGG from LGG, AUC values were 0.955 for Ki-67 LI; 0.926 for α; 0.903 for Dslow; 0.897 for f; 0.863 for DDC; 0.852 for ADC; 0.820 for Dfast (P < 0.001 for all). The parameters ADC, Dslow, Dfast, f, DDC, and α showed moderate to good negative correlation with Ki-67 LI (P < 0.001 for all). The ICCs of all the parameters were found greater than 0.75 (P < 0.05 for all) suggesting good reliability of measurements. CONCLUSION: In comparison to ADC derived from monoexponential model, the parameters α and Dslow derived from stretched exponential, and biexponential models respectively can efficiently differentiate HGG from LGG with high diagnostic accuracy. Additionally, f and DDC derived from biexponential, and stretched exponential models respectively are also more useful in differentiating HGG from LGG in comparison to ADC.

Clinical significance of miR-1298 in cervical cancer and its biological function in vitro.

Cervical cancer is one of the most malignant tumors in women. miR-1298 was reported to be abnormally expressed and serve crucial role in tumorigenesis of several types of cancer; however, the role of miR-1298 in cervical cancer remains unknown. The present study aimed to evaluate the clinical and biological significance of miR-1298 in cervical cancer. To do so, the expression level of miR-1298 in cervical cancer tissues and cells was evaluated by reverse transcription quantitative PCR. Kaplan-Meier survival analysis and Cox regression analysis were used to explore the prognostic significance of miR-1298 in patients with cervical cancer. Cell Counting Kit-8 and Transwell migration and invasion assays were used to evaluate the effect of miR-1298 on the proliferative, migratory and invasive abilities of cervical cancer cells, respectively. The expression of miR-1298 was lower in cancer tissues and cells compared with normal tissues and cells. Furthermore, miR-1298 expression was associated with lymph node metastasis, tumor diameter and staging from the International Federation of Gynecology and Obstetrics. In addition, patients with low miR-1298 expression had poorer overall survival. These findings suggested that miR-1298 may be considered as an independent prognostic factor for patients with cervical cancer. Furthermore, the results demonstrated that miR-1298 knockdown could promote tumor cell proliferation and migratory and invasive abilities. In addition, nucleus accumbens-associated 1 (NACC1) was demonstrated to be a direct target of miR-1298. Taken together, these findings indicated that miR-1298 overexpression may be considered as a prognostic biomarker for cervical cancer and that miR-1298 may play an inhibitor role in cervical cancer by targeting NACC1.

Long-term microstructure and cerebral blood flow changes in patients recovered from COVID-19 without neurological manifestations.

BACKGROUNDThe coronavirus disease 2019 (COVID-19) rapidly progressed to a global pandemic. Although some patients totally recover from COVID-19 pneumonia, the disease's long-term effects on the brain still need to be explored.METHODSWe recruited 51 patients with 2 subtypes of COVID-19 (19 mild and 32 severe) with no specific neurological manifestations at the acute stage and no obvious lesions on the conventional MRI 3 months after discharge. Changes in gray matter morphometry, cerebral blood flow (CBF), and white matter (WM) microstructure were investigated using MRI. The relationship between brain imaging measurements and inflammation markers was further analyzed.RESULTSCompared with healthy controls, the decrease in cortical thickness/CBF and the changes in WM microstructure were more severe in patients with severe disease than in those with mild disease, especially in the frontal and limbic systems. Furthermore, changes in brain microstructure, CBF, and tract parameters were significantly correlated (P < 0.05) with the inflammatory markers C-reactive protein, procalcitonin, and interleukin 6.CONCLUSIONIndirect injury related to inflammatory storm may damage the brain, altering cerebral volume, CBF, and WM tracts. COVID-19-related hypoxemia and dysfunction of vascular endothelium may also contribute to neurological changes. The abnormalities in these brain areas need to be monitored during recovery, which could help clinicians understand the potential neurological sequelae of COVID-19.FUNDINGNatural Science Foundation of China.

Cryptosporidium parvum upregulates miR-942-5p expression in HCT-8 cells via TLR2/TLR4-NF-κB signaling.

BACKGROUND: Micro (mi)RNAs are small noncoding RNA molecules that function in RNA silencing and post-transcriptional regulation of gene expression. This study investigated host miRNA activity in the innate immune response to Cryptosporidium parvum infection. METHODS: In vitro infection model adopts HCT-8 human ileocecal adenocarcinoma cells infected with C. parvum. The expression of miR-942-5p was estimated using quantitative real-time polymerase chain reaction (qPCR). The TLRs-NF-κB signaling was confirmed by qPCR, western blotting, TLR4- and TLR2-specific short-interfering (si)RNA, and NF-κB inhibition. RESULTS: HCT-8 cells express all known toll-like receptors (TLRs). Cryptosporidium parvum infection of cultured HCT-8 cells upregulated TLR2 and TLR4, and downstream TLR effectors, including NF-κB and suppressed IκBα (nuclear factor of kappa light polypeptide gene enhancer in B cells inhibitor, alpha). The expression of miR-942-5p was significantly upregulated at 4, 8, 12 and 24 h post-infection, and especially at 8 hpi. The results of TLR4- and TLR2-specific siRNA and NF-κB inhibition showed that upregulation of miR-942-5p was promoted by p65 subunit-dependent TLR2/TLR4-NF-κB pathway signaling. CONCLUSIONS: miR-942-5p of HCT-8 cells was significantly upregulated after C. parvum infection, especially at 8 hpi, in response to a p65-dependent TLR2/TLR4-NF-κB signaling. TLR4 appeared to play a dominant role.

[Detection of a BRCA1 c.2013_2014ins GT variant an ethnic Han Chinese pedigree affected with breast cancer].

OBJECTIVE: To detect potential variant in an ethical Han Chinese pedigree affected with breast cancer. METHODS: The proband and her relatives were subjected to next-generation sequencing using a target capture sequencing kit containing 121 cancer-related genes. Candidate variants were selected by analysis of their type, frequency in population, and segregation with the phenotype. Candidate variant was verified by Sanger sequencing and TA cloning. RESULTS: A c.2013_2014ins GT variant was detected in the BRCA1 gene among all breast cancer patients from this pedigree but not among healthy females. The variant was not recorded in the 1000 Genome Project database or the Exome Aggregation Consortium (ExAC) database. The frameshifting insertion was predicted to form an premature stop codon in gene transcript and can give rise to a truncated protein. CONCLUSION: The BRCA1 c.2013_2014ins GT variant probably underlies the pathogenesis of breast cancer in this Chinese pedigree.

Amid proton transfer (APT) and magnetization transfer (MT) MRI contrasts provide complimentary assessment of brain tumors similarly to proton magnetic resonance spectroscopy imaging (MRSI).

OBJECTIVES: Using MRSI as comparison, we aimed to explore the difference between amide proton transfer (APT) MRI and conventional semi-solid magnetization transfer ratio (MTR) MRI, and to investigate if molecular APT and structural MTR can provide complimentary information in assessing brain tumors. METHODS: Seventeen brain tumor patients and 17 age- and gender-matched volunteers were included and scanned with anatomical MRI, APT and MT-weighted MRI, and MRSI. Multi-voxel choline (Cho) and N-acetylaspartic acid (NAA) signals were quantified from MRSI and compared with MTR and MTRasym(3.5ppm) contrasts averaged from corresponding voxels. Correlations between contrasts were explored voxel-by-voxel by pooling values from all voxels into Pearson's correlation analysis. Differences in correlation coefficients were tested with the Z-test (set at p<0.05). RESULTS: APT and MT provide good contrast and quantitative parameters in tumor imaging, as do the metabolite (Cho and NAA) maps. MTRasym(3.5ppm) significantly correlated with MTR (R=-0.61, p<0.0001), Cho (R=0.568, p<0.0001) and NAA (R=-0.619, p<0.0001) in tumors, and MTR also significantly correlated with Cho (R=-0.346, p<0.0001) and NAA (R=0.624, p<0.0001). In healthy volunteers, MTRasym(3.5ppm) was non-significantly correlated with MTR (R=-0.049, p=0.239), Cho (R=0.030, p=0.478) and NAA (R=-0.083, p=0.046). Significant correlations were found among MTR with Cho (R=0.199, p<0.0001) and NAA (R=0.263, p<0.0001) in the group of healthy volunteers with lower correlation R values than those in tumor patients. CONCLUSIONS: APT and MT could provide independent and supplementary information for the comprehensive assessment of molecular and structural changes due to brain tumor cancerogenesis. KEY POINTS: • MTR asym(3.5ppm) positively correlated with Cho while negatively with NAA in tumors. • MTR positively correlated with NAA while negatively with Cho in tumors. • Combining APT/MT provides molecular and structural information similarly to MRSI.

miR-149 reverses cisplatin resistance of gastric cancer SGC7901/DDP cells by targeting FoxM1.

Drug resistance remains a major unresolved obstacle for gastric cancer (GC) treatment. Recently, increasing studies have showen that microRNAs (miRNAs) are involved in cancer chemotherapeutic resistance and can potentially be applied to reverse drug resistance in cancers. The relationship between miRNA-149 expression and cisplatin (DDP) resistance in GC cells is still unknown. Here, we detected miR-149 expression by using RT-PCR and found that expression of miR-149 was downregulated in SGC7901/DDP cells compared with SGC7901cells, indicating a role of miR-149 in determining cisplatin-resistance of GC cells. Then, SGC7901/DDP cells were tansfected with miR-149 mimics, MTT assay was performed to determine SGC7901/DDP cell viability, and showed that overexpression of miR-149 inhibited the cell viability after cisplatin treatment, suggesting that up-regulation of miR-149 enhanced SGC7901/DDP cell sensitivity to cisplatin. Furthermore, we confirmed that Forkhead box M1 (FoxM1) is a direct target of miR-149 in SGC7901/DDP cells by using luciferase reporter assay. Besides, we also demonstrated that miR-149 enhances SGC7901/DDP cell sensitivity to cisplatin by downregulating FoxM1 expression. In summary, our data provide new insights that miR-149 plays an important role in determining sensitivity of cisplatin-resistant GC cells by targeting FoxM1 and suggest that miR-149 could be a potential target for reversing drug resistance in GC.

Interchain impacts on electronic structures of heterocyclic oligomers and polymers containing group 14, 15, and 16 heteroatoms: quantum chemical calculations in combination with molecular dynamics simulations.

The packing structures and packing effects on excitation energies of oligomers of polyfuran (PFu), polypyrrole (PPy), polycyclopentidene (PCp), polythiophene (PTh), polyphosphole (PPh), and polysilole (PSi) are comparatively studied by employing molecular dynamics (MD) simulations and time-dependent density functional theory (TDDFT) calculations. The dependence of packing structures on the main group of heteroatoms in the five-membered heterocyclic oligomers is exhibited from MD simulations. The planarity of backbones and the population of pi-stacked structures increase with the heteroatoms going from group 14 to group 16; i.e., PCp < PPy < PFu; PSi < PPh < PTh. The polymers with the third row elements, PSi and PPh, tend to have larger chain flexibilities in the packing systems than those with the second row elements, PCp and PPy, respectively. On the basis of the second-order Møller-Plesset perturbation (MP2) and natural bond orbital (NBO) calculations of the pi-stacked pairs, the difference in pi-stack orientations, head-to-tail vs head-to-head, between various packing systems is rationalized by individual interchain bond orbital interactions involved with heteroatoms. The packing systems with higher row elements tend to have narrower band gaps. The band gaps are closely related to the chain torsions driven by interchain interactions. The noticeable chain distortions in the packing systems of PCp, PSi, and PPh lead to the significant increase of band gaps in comparison with those appraised from periodic boundary conditions (PBC) calculations on their planar isolated chains.