SQSTM1-mediated clearance of cytoplasmic mutant TARDBP/TDP-43 in the monkey brain

The cytoplasmic accumulation and aggregates of TARDBP/TDP-43 (TAR DNA binding protein) are a pathological hallmark in amyotrophic lateral sclerosis and frontotemporal lobar degeneration. We previously reported that the primate specific cleavage of TARDBP accounts for its cytoplasmic mislocalization in the primate brains, prompting us to further investigate how the cytoplasmic TARDBP mediates neuropathology. Here we reported that cytoplasmic mutant TARDBP reduced SQSTM1 expression selectively in the monkey brain, when compared with the mouse brain, by inducing SQSTM1 mRNA instability via its binding to the unique 3'UTR sequence (GU/UG)n of the primate SQSTM1 transcript. Overexpression of SQSTM1 could diminish the cytoplasmic C-terminal TARDBP accumulation in the monkey brain by augmenting macroautophagy/autophagy activity. Our findings provide additional clues for the pathogenesis of cytoplasmic TARDBP and a potential therapy for mutant TARDBP-mediated neuropathology.

In Situ Synthesis of Organopolysulfides Enabling Spatial and Kinetic Co-Mediation of Sulfur Chemistry

Li-S batteries have been regarded as one of the most promising alternatives of the next-generation Li batteries. However, the dissolution and shuttling of lithium polysulfides lead to low cycle stability and low Coulombic efficiency, which intensively hinder the practical application of Li-S batteries. Herein, we propose a strategy to simultaneously promote the redox kinetics and inhibit the shuttle of lithium polysulfides, through in situ synthesis of insoluble organopolysulfides by adding a special additive. Attractively, the thus-formed insoluble organopolysulfides in the form of nanoparticle aggregates are also capable of adsorbing unconverted lithium polysulfides and hence effectively spatially suppress the shuttle effect. Furthermore, the organopolysulfides served as active redox mediators, showing faster redox kinetics of S chemistry than that of lithium polysulfides. As a result, the Li-S batteries showed impressive capacity, improved rate performance, and long cycling stability even under lean-electrolyte and high sulfur loading conditions.

[Interventional effect of asiaticosdide on rats exposed to silica dust]

Objective: To investigate the effect of asiaticoside for fibrosis in lung tissues of rats exposed to silica and to explore its possible mechanism. Methods: 144 SD male rats were randomly divided into control group, model group, positive drug control group, asiaticoside high-dose group, medium-dose group and low-dose group, each group included 24 rats. Rats in the control group were perfused with 1.0 ml of normal saline, and the other groups were given 1.0 ml 50 mg/ml SiO(2) suspension. Gavage of herbal was given from the next day after model establishment, once a day. Rats in the positive drug control group were administration with 30 mg/kg tetrandrine and rats in the low-dose group, medium-dose group and high-dose group were given 20 mg/kg, 40 mg/kg and 60 mg/kg asiaticoside for fibrosis respectively. Rats in the control group and the model group were given 0.9% normal saline. The rats were sacrificed in on the 14th, 28th and 56th day after intragastric administration and collect the lung tissues to detect the content of hydroxyproline, TGF-β(1) and IL-18, observe the pathological changes of the lung tissues by HE and Masson staining and determine the expressions of Col-I, a-SMA, TGF-β in lung tissues by Western Blot. Results: On the 14th day, 28th day and 56th day after model establishment, the lung tissues of rats in the model group showed obvious inflammatory response and accumulation of collagen fibers, and the degree of inflammation and fibrosis increased with time. The intervention of asiaticoside could effectively inhibit the pathological changes of lung tissues. The contents of hydroxyproline, IL-18 and TGF-β1 in lung tissues of model group were higher than those in the control group (P<0.05) , while the level of hydroxyproline, IL-18 and TGF-β1 in asiaticoside groups were significantly decreased, and the difference was statistically signicant (P<0.05) . Compared with the control group, the expression levels of Col-I, TGF-β1and α-SMA in lung tissue of model group were increased (P<0.05) , while the expression level of Col-I, TGF-β1 and α-SMA were decreased after the intervention of asiaticoside, and the difference was statistically signicant (P<0.05) . Conclusion: Asiaticoside can inhibit the increase of Col-I, TGF-β1 and α-SMA content in the SiO(2)-induced lung tissues of rats, reduce the release of TGF-β1 and IL-18 inflammatory factors in lung tissue, and then inhibit the synthesis and deposition of extracellular matrix in rat lung tissue, and improve silicosis fibrosis.

Low-Glycemic Index Diets as an Intervention in Metabolic Diseases: A Systematic Review and Meta-Analysis

We aimed to investigate the effects of a low-glycemic index (GI) diet on the body mass and blood glucose of patients with four common metabolic diseases by conducting a systematic review and meta-analysis of studies comparing a low-GI diet (LGID) and other types of diet. Search terms relating to population, intervention, comparator, outcomes, and study design were used to search three databases: PubMed, Embase, and the Cochrane Library. We identified 24 studies involving 2002 participants. Random-effects models were used for 16 studies in the meta-analysis and stratified analyses were performed according to the duration of the intervention. The systematic review showed that LGIDs slightly reduced body mass and body mass index (BMI) (p < 0.05). BMI improved more substantially after interventions of >24 weeks and there was no inter-study heterogeneity (I² = 0%, p = 0.48; mean difference (MD) = -2.02, 95% confidence interval (CI): -3.05, -0.98). Overall, an LGID had superior effects to a control diet on fasting blood glucose (FBG) and glycosylated hemoglobin. When the intervention exceeded 30 days, an LGID reduced FBG more substantially (MD = -0.34, 95% CI: -0.55, -0.12). Thus, for patients with metabolic diseases, an LGID is more effective at controlling body mass and blood glucose than a high-GI or other diet.

[Evaluation of papilledema and visual improvement in patients with idiopathic intracranial hypertension after venous sinus stenting]

Objective: To evaluate the improvement of papilledema and visual acuities in patients with idiopathic intracranial hypertension (IIH) after venous sinus stenting. Methods: The clinical data of 8 IIH patients who met the inclusion criteria underwent venous sinus stenting between January 2013 and December 2016 at Department of Neurosurgery, Tianjin Huanhu Hospital were analyzed retrospectively. There were 6 females and 3 males,aged (32.9±14.4)years (range:19 to 57 years).The thickness of the retinal nerve fiber layer (RNFL) was measured by optical coherence tomography. Fundus,visual acuity and visual field examination were performed before and after operation. If pressure gradient ≥10 mmHg(1 mmHg=0.133 kPa) across the venous stenosis was indicated by intraoperative pressure measurement,the patient would be treated with venous sinus stenting. Intracranial pressure was measured by lumbar puncture 3 to 7 days after operation. RNFL thickness and eye examination were detected 6 months after surgery. CT venogram was used to observe the sinus venous conditions. Paired t test was used to compare the data before and after surgery. Results: All the 8 patients underwent venous sinus stenting successfully. The mean pressure gradient across the venous stenosis was reduced from (24±9.2) mmHg to (2.6±2.0) mmHg (t=8.02,P<0.01). Intracranial pressure decreased from preoperative (41.4±12.7) cmH₂O(1 cmH₂O=0.098 kPa) to postoperative (12.9±3.3) cmH₂O (t=7.08, P<0.01). The RNFL thickness decreased from (275.3±68.3)μm to (131.4±31.8)μm(t=5.80,P<0.05) 6 months after surgery and the baseline visual acuity was improved from(M(Q_R))0.24 (0.25) to 0.65 (0.23)(Z=-2.52,P<0.05).Papilledema was significantly improved in 6 patients,and no significant change in 2 patients. CT venogram indicated adjacent stent restenosis in 1 patient. Conclusion: Venous sinus stenting can effectively improve papilledema and visual acuity caused by IIH.

[Interventional effect of metformin on pulmonary inflammation and pulmonary fibrosis in silicotic rats]

Objective: To investigate the interventional effect of metformin on pulmonary inflammation and pulmonary fibrosis in silicotic rats. Methods: In April 2019, 48 Wistar male rats of SPF grade were randomly divided into negative control group, metformin control group, silicon dioxide (SiO₂) model group, low, medium and high dose metformin intervention group according to the random number table method, 8 rats in each group. The SiO₂ model group and the low, medium and high dose metformin intervention groups were given 1 ml 50 mg/ml of SiO₂ by intratracheal instillation, the negative control group and the metformin control group were given 1 ml normal saline by intratracheal instillation. 24 hours later, the low, medium and high dose metformin intervention groups and the metformin control group were treated with 100, 200, 400 and 400 mg/kg metformin daily, the control and SiO₂ model groups received normal saline daily. Then the rats were sacrificed at the 28th day after SiO₂ exposure. The changes of rat body weight and pathological examination of rat lung tissue were observed, and the lung organ coefficient, the content of hydroxyproline (HYP) , the expression levels of inflammatory factors transforming growth factor beta1 (TGF-β1) , tumor necrosis factor-alpha (TNF-α) , interleukin-1beta (IL-1β) and the protein expression of E-cadherin (E-Cad) , Vimentin, α-SMA were detected. Results: Compared with the negative control group, SiO₂ model group had a significant decrease in the body weight of rats (P<0.05) , lung organ coefficient, alveolitis and fibrosis scores, HYP content and the levels of TGF-β1, TNF-α, IL-1β were all significantly increased (P<0.05) . Compared with the SiO₂ model group, the weights of the rats in the medium and high dose intervention group of metformin increased significantly (P<0.05) . And after intervention with different doses of metformin, the lung organ coefficient, alveolitis and fibrosis scores, HYP content and the levels of TGF-β1, TNF-α and IL-1β were significantly decreased (P<0.05) . Immunohistochemistry and Western blotting results showed that compared with the negative control group, the expression of E-Cad of the SiO₂ model group was decreased, and the expression levels of Vimentin and α-SMA were significantly increased (P<0.05) . After metformin intervention, the expression of E-Cad was significantly increased, the expression levels of Vimentin and α-SMA were significantly decreased (P<0.05) . Conclusion: Metformin can reduce lung tissue inflammation and fibrosis in rats exposed to SiO₂ dust, which may be related to reducing the expression of inflammatory factors in lung tissue and inhibiting the EMT process.

Retrospective Analysis on Traumatic Rupture of Intracranial Internal Carotid Artery in 11 Cases

Abstract

Objective To retrospectively analyze the characteristics of the traumatic rupture of intracranial internal carotid artery in order to provide reference for forensic expertise examination and identification. Methods A total of 11 autopsy cases of traumatic rupture of intracranial internal carotid artery were collected. The gender, age, cause of injury, blood loss on the scene, location of internal carotid artery rupture, hardening degree of the rupture of the wall, brain injury, blood ethanol content and cause of death were also recorded. Results All 11 cases died on the scene, of which 7 died from traffic accidents, 2 falls from height and 2 from bare handed injuries. None of the 11 victims suffered serious head and body surface injury. The internal carotid artery rupture in the 9 cases of traffic injury and fall from height injury occurred in the cavernous segment. In all these cases, there were transverse fractures of the middle cranial fossa with the carotid sulcus involved, and minor intracranial hemorrhage and brain contusion. In 2 cases of bare handed injuries, internal carotid artery rupture occurred in the ophthalmic artery segment, accompanied by fatal intracranial hemorrhage and diffuse axonal injury, but no skull fracture. All 11 cases showed full-thickness rupture of the vessel wall, and the long axis of the wounds was perpendicular to those of the artery. Conclusion The incidence of intracranial internal carotid artery rupture in high-energy trauma events such as traffic accidents and high falls deserves attention. Injuries of the cavernous segment or ophthalmic segment might be more common. The main injury mechanism of intracranial internal carotid artery rupture might be that the blood vessels were pulled and the bone fragments caused damage.

Forensic Analysis of 105 Autopsy Cases of Psychiatric Patients

Abstract

Objective To provide reference for medical and health services and forensic expertise, the causes and manners of death of psychiatric patients were analyzed retrospectively. Methods A total of 105 autopsy cases of psychiatric patients accepted and settled by Institute of Forensic Science of Criminal Investigation Police University of China from 2004 to 2019 were collected. The cases were divided into four groups： disease death, suicidal death, accidental death and homicidal death. The common causes of death of each group were statistically analyzed and the differences in age, disease duration, body mass index （BMI） and gender among the groups were assessed. Results Of the 105 cases, 60 were male and 45 were female, the course of psychosis was （12.9±10.4） years, the age of the deceased was （51.3±11.4） years, and 61.0% was schizophrenic. There were 50 cases （47.6%） in the disease death group, in which the psychiatric patients were the oldest and had the longest course of psychosis and lowest BMI. Pulmonary thromboembolism, respiratory infections, and cardiogenic disease were the most common causes of death in the group. There were 26 accidental deaths （24.8%）, among which traffic accidents were the most common cause of death. There were 15 homicidal deaths （14.3%）, all of which were male, with craniocerebral injury being the most common cause of death. There were 14 suicidal deaths （13.3%）. In suicidal death group, the age of the deceased was the youngest, the course of psychosis was the shortest and falling from the height was the most common way to commit suicide. Conclusion Understanding the common causes of death of psychiatric patients may contribute to developing measures to reduce the mortality rate of the population. It is necessary to investigate the age, course of psychosis and gender of the deceased when assessing the manner of death.

Transferable Multilevel Attention Neural Network for Accurate Prediction of Quantum Chemistry Properties via Multitask Learning

The development of efficient models for predicting specific properties through machine learning is of great importance for the innovation of chemistry and material science. However, predicting global electronic structure properties like Frontier molecular orbital highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels and their HOMO-LUMO gaps from the small-sized molecule data to larger molecules remains a challenge. Here, we develop a multilevel attention neural network, named DeepMoleNet, to enable chemical interpretable insights being fused into multitask learning through (1) weighting contributions from various atoms and (2) taking the atom-centered symmetry functions (ACSFs) as the teacher descriptor. The efficient prediction of 12 properties including dipole moment, HOMO, and Gibbs free energy within chemical accuracy is achieved by using multiple benchmarks, both at the equilibrium and nonequilibrium geometries, including up to 110,000 records of data in QM9, 400,000 records in MD17, and 280,000 records in ANI-1ccx for random split evaluation. The good transferability for predicting larger molecules outside the training set is demonstrated in both equilibrium QM9 and Alchemy data sets at the density functional theory (DFT) level. Additional tests on nonequilibrium molecular conformations from DFT-based MD17 data set and ANI-1ccx data set with coupled cluster accuracy as well as the public test sets of singlet fission molecules, biomolecules, long oligomers, and protein with up to 140 atoms show reasonable predictions for thermodynamics and electronic structure properties. The proposed multilevel attention neural network is applicable to high-throughput screening of numerous chemical species in both equilibrium and nonequilibrium molecular spaces to accelerate rational designs of drug-like molecules, material candidates, and chemical reactions.

Long noncoding RNA SNHG14 regulates ox-LDL-induced atherosclerosis cell proliferation and apoptosis by targeting miR-186-5p/WIPF2 axis

To investigate the role of small nucleolus RNA host gene 14 (SNHG14) in the progression of atherosclerosis (AS), bioinformatics analysis, and other relevant experiments (cell counting kit-8, flow cytometry, quantitative real-time polymerase chain reaction, luciferase reporter, RNA immunoprecipitation, RNA pull-down, and western blot assays) were done. The current study revealed that SNHG14 level was high in the serum of AS patients and oxidized low-density lipoprotein (ox-LDL)-induced AS cell lines. Besides, we found that SNHG14 accelerated cell proliferation while inhibited cell apoptosis in ox-LDL-induced AS cell lines. Next, SNHG14 was confirmed to be a sponge for miR-186-5p in AS cells, and it was validated that SNHG14 regulated AS cell proliferation and apoptosis by sponging miR-186-5p. Moreover, we uncovered that WAS-interacting protein family member 2 (WIPF2) was a downstream target of miR-186-5p in AS cells. Finally, it was demonstrated that miR-186-5p modulated AS cell proliferation and apoptosis via targeting WIPF2. To conclude, our research disclosed that SNHG14 affected ox-LDL-induced AS cell proliferation and apoptosis through miR-186-5p/WIPF2 axis, which may provide a theoretical basis for the treatment and diagnosis of AS.

Noncovalently Fused-Ring Electron Acceptors with C2v Symmetry for Regulating the Morphology of Organic Solar Cells

Four noncovalently fused-ring electron acceptors p-DOC6-2F, o-DOC6-2F, o-DOC8-2F, and o-DOC2C6-2F have been designed and synthesized. p-DOC6-2F and o-DOC6-2F have the same molecular backbone but different molecular shapes and symmetries. p-DOC6-2F has an S-shaped molecular backbone and C_2h symmetry, whereas o-DOC6-2F possesses a U-shaped molecular backbone and C_2v symmetry. The molecular shape and symmetry can influence the dipole moment, solubility, optical absorption, energy level, molecular packing, and film morphology. Compared with the corresponding p-DOC6-2F, o-DOC6-2F exhibits better solubility, a wider band gap, and a larger dipole moment. When blended with the donor polymer PBDB-T, the C_2v symmetric o-DOC6-2F can form an appropriate active layer morphology, whereas the C_2h symmetric p-DOC6-2F forms oversized domains. Organic solar cells (OSCs) based on p-DOC6-2F, o-DOC6-2F, o-DOC8-2F, and o-DOC2C6-2F obtained power conversion efficiencies of 9.23, 11.87, 11.23, and 10.80%, respectively. The result reveals that the molecular symmetry can facilely regulate the performance of OSCs.

MicroRNA‑195 suppresses cell proliferation, migration and invasion in epithelial ovarian carcinoma via inhibition of the CDC42/CCND1 pathway

Epithelial ovarian carcinoma (EOC) is the most common cause of gynecological cancer mortality, and poses a threat to women. MicroRNA-195 (miR-195) has been reported to induce apoptosis of human OVCAR-3 cells by inhibiting the VEGFR2/AKT pathway. However, the role of miR-195 in EOC remains unknown. A previous study reported that cell division cycle 42 (CDC42) can serve as a target gene of miR-195 and mediate malignant progression of esophageal squamous cell carcinoma (ESCC). The aim of the present study was to investigate the role of miR-195 in EOC and the regulation in CDC42/CCND1 pathway. Tissues samples and clinical materials were collected from 78 enrolled patients with EOC to analyze the expression and clinical significance of miR-195, CDC42 and cyclin D1 (CCND1). Human EOC cell lines OVCA420, OVCAR-3, A2780 and SKOV3 cell lines were used to assess the expression and function of miR-195, CDC42 and CCND1 in vitro. Cell proliferation, the cell cycle and apoptosis, as well as the cell migratory and invasive abilities were detected in vitro using BrdU incorporation, colony formation, wound healing and Transwell invasion assays, along with flow cytometry. miR-195 was downregulated, while CDC42 and CCND1 were upregulated in human EOC tissues and cells, and the aberrant expression of both was associated with increased EOC malignancy. Moreover, miR-195 expression was negatively correlated with CDC42 and CCND1 expression levels, and negatively regulated these expression levels. Thus, it was suggested that miR-195 functions as a tumor suppressor, but CDC42 and CCND1 act as tumor promoters based their abilities to enhance cell proliferation, cell cycle entry, migration and invasion, as well as decrease apoptosis in OVCAR-3 cells. the present results demonstrated that miR-195 inhibited human EOC progression by downregulating CDC42 and CCND1 expression. Furthermore, it was identified that miR-195, CDC42 and CCND1 may be effective biomarkers for EOC diagnosis and treatment.

[Analysis of the relationship between the changes of lung function and serum proinflammatory cytokines in workers occupationally exposed to toluene diisocyanate]

Objective: To analyze the correlation between the changes of lung function and serum proinflammatory cytokines in workers occupationally exposed to toluene diisocyanate (TDI), and to explore the evaluation index of respiratory toxicity of TDI. Methods: In October 2014, 61 male workers engaged in TDI synthesis process, purification process, packaging process and the above production process in a TDI factory in western China were selected as TDI exposure group; 62 male enterprise managers who were not exposed to TDI and other known allergenic chemicals were selected as control group, which were matched at the age of workers in exposure group. The questionnaire survey obtained information such as gender, length of service, age, occupational history, exposed length of service and so on. The lung function indexes [forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), FEV1/FVC] and serum levels of interleukin (IL)-1 β, IL-6, IL-8, tumor necrosis factor (TNF)-α, macrophage inflammatory factor-1 β, monocyte chemoattractant factor-1 and vascular endothelial growth factor were measured. The urine was collected after the weekend shift, and the concentration of (TDA), the metabolite of TDI, was determined as the index of internal exposure. Spearman rank correlation was used to analyze the correlation between cytokines and lung function indexes, and multivariate linear regression was used to analyze the changes of lung function indexes and cytokines with TDI exposure concentration and time. Results: The median age (P₅-P₉₅) of the exposed group and the control group was 36.5 (24.0-51.0) and 38.0 (24.0-50.0) years, respectively. In the exposed group, the median length of service (P₅-P₉₅) was 6.94 (0.97-26.33) years, and the median concentration of TDA in urine was 15.56 (2.28-112.16) ng/ml. The three indexes of lung function, FVC, FEV1, FEV1/FVC and the levels of serum IL-8 and TNF-α were significantly lower than those in the control group (P<0.01). With the increase of exposure concentration and exposure time, the level of serum TNF-α, FVC and FEV1 decreased, and showed a good dose-effect and time-effect relationship (all P_trend values< 0.05). Serum IL-8 and TNF-α were positively correlated with FVC, FEV1 and FEV1/FVC (all P values<0.01). Conclusion: The levels of serum inflammatory factors IL-8 and TNF-α in worker exposed to TDI are related to lung function indexes, which can be used as early evaluation indexes of respiratory toxicity induced by TDI.

Excessive daytime sleepiness with snoring or witnessed apnea is associated with handgrip strength: a population-based study

BACKGROUND

Sarcopenia is emerging as an important public health problem, and evidences have determined that poor sleep is associated with muscle strength, but the potential effects of excessive daytime sleepiness (EDS), snoring and witnessed apnea on handgrip strength have not been evaluated.

AIM

We aimed to examine the association between EDS, snoring, witnessed apnea and muscle strength in an adult population.

DESIGN

Cross-sectional study.

METHODS

This cross-sectional study comprised 19 434 adults. Handgrip strength was measured using a handheld digital dynamometer. EDS was assessed by Epworth Sleepiness Scale, snoring and witnessed apnea during sleep were reported through simple yes/no questions. Analysis of covariance was carried out to determine the association between EDS with snoring or witnessed apnea and muscle strength.

RESULTS

The means (95% confidence interval) for average handgrip strength/body weight (kg/kg) across symptoms categories were 0.396 (0.333-0.472), 0.393 (0.330-0.467), 0.396 (0.333-0.471) and 0.386 (0.325-0.460) (P < 0.0001), respectively. Similar results were observed with maximal handgrip strength/body weight (kg/kg).

CONCLUSIONS

Self-reported EDS accompanied with snoring or apnea is associated with lowest handgrip strength, independently of confounding factors. Whether improvement of EDS, snoring and apnea, can ameliorate age-associated decline in muscle strength warrants further studies.

[Expression changes of miRNA-29b-3p and miRNA-34c-3p in lung tissue of rats exposed to silica and A549 cells]

Objective: To investigate the role of microRNA-29b-3p (miRNA-29b-3p) and miRNA-34c-3p in the process of pulmonary fibrosis, we detected the expression levels of miRNA-29b-3p and miRNA-34c-3p in the lung tissue of rats exposed to silica and A549 cells. Methods: SPF male Wistar rats were randomly divided into 1, 7, 14, 21, 28 d control group and silica (SiO(2)) dusting group, with 6 rats in each group. One-time non-exposure method was used to infuse 1ml SiO(2) suspension. The rat SiO(2) dusting group was established in the liquid, and the control rats were intratracheally injected with 1 ml of sterile physiological saline in the same manner. The lung tissues of each group were collected at the corresponding time points after dusting. Three of the rats were taken out for pathological observation, and the other three were used to screen differentially expressed miRNAs in lung tissue by miRNA microarray technology. A549 cells were cultured at the in vitro cell level and divided into control group, SiO(2) stimulation group and TGF-β(1) stimulation group, and cells were collected at 12, 24 and 48 h after treatment. The expression levels of miRNA-29b-3p and miRNA-34c-3p in rat lung tissue and A549 cells were verified by real-time PCR (qRT-PCR), target gene prediction of miRNA-29b-3p and miRNA-34c-3p and perform GO enrichment analysis and KEGG pathway analysis. Results: The weight growth rate of the control group was significantly higher than that of the SiO(2) dusting group. Compared with the control group, the lung mass and lung coefficient of the SiO(2) dusting group were significantly increased (P<0.05). The inflammatory response of the lungs in the control group was significantly reduced at 21 and 28 days, and the inflammatory cells infiltrated in the lung tissue of the SiO2 group. The rats in the control group had a small amount of collagen at 21 and 28 days. A large amount of collagen fiber deposition began to appear in the lung tissue of rats exposed to SiO(2) for 21 days. Compared with the control group, the expression levels of miRNA-29b-3p and miRNA-34c-3p in the SiO(2) dusting group were significantly down-regulated, and there was significant difference compared with the control group (P<0.05). The expression levels of miRNA-29b-3p and miRNA-34c-3p in A549 cells treated with SiO(2) and human recombinant TGF-β1 were significantly lower than those in the control group at 24 h and 48 h, and the difference was statistically significant (P<0.05). Conclusion: Down-regulation of miRNA-29b-3p and miR-34c-3p in rat lung tissue A549 cells may be associated with the development of early silicosis and is expected to be an indicator of early silicosis diagnosis and prognosis.

Magnetic domains characterization of crystalline Fe3O4 under DC and AC magnetic field

Fe3O4 nanoparticles with crystallite sizes around 10 nm were synthesized by an emulsion method. X-ray diffractometer (XRD) shows that nanocrystalline Fe3O4 possesses face center cubic structure. The magnetic characteristics are investigated by magnetic force microscopy (MFM). Magnetic field directions were applied parallel and perpendicular to the Fe3O4 sample surface for magnetic measurements. Under the perpendicular magnetic field, the phase images of most magnetic nanoparticles exhibit bright or dark MFM contrast. In comparison, the parallel field phase images display a bright-dark dipole MFM contrast, with in-plane magnetic domain configurations. Furthermore, the investigation of strip domains inside Fe3O4 particles under altering magnetic fields indicates the existence of magnetic anisotropy energies, dipole energies as well as inter-grain coupling energies inside the clusters. This approach for probing magnetic responses on nanoscale magnetic domains can be further extended to the analysis of local physical features.