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1.
J Mol Neurosci ; 2020 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-32036579

RESUMO

Focal cortical dysplasia (FCD) is the main cause of medically intractable pediatric epilepsy. Previous studies have suggested that alteration of cortical interneurons and abnormal cytoarchitecture have been linked to initiation and development for seizure. However, whether each individual subpopulation of cortical interneurons is linked to distinct FCD subtypes remains largely unknown. Here, we retrospectively analyzed both control samples and epileptic specimens pathologically diagnosed with FCD types Ia, IIa, or IIb. We quantified three major interneuron (IN) subpopulations, including parvalbumin (PV)-, somatostatin (Sst)-, and vasoactive intestinal peptide (Vip)-positive INs across all the subgroups. Additionally, we calculated the ratio of the subpopulations of INs to the major INs (mINs) by defining the total number of the PV-, Sst-, and Vip-INs as mINs. Compared with the control, the density of the PV-INs in FCD type IIb was significantly lower, and the ratio of PV/mINs was lower in the superficial part of the cortex of the FCD type Ia and IIb groups. Interestingly, we found a significant increase in the ratio of Vip/mINs only in FCD type IIb. Overall, these results suggest that in addition to a reduction in PV-INs, the increase in Vip/mINs may be related to the initiation of epilepsy in FCD type IIb. Furthermore, the increase in Vip/mINs in FCD type IIb may, from the IN development perspective, indicate that FCD type IIb forms during earlier stages of pregnancy than FCD type Ia.

2.
Leuk Lymphoma ; : 1-7, 2020 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-32036728

RESUMO

LILRB4 is expressed in AML M4/M5 cells and negatively regulates immune cell activation via T-cell suppression. Its expression and role in chronic myelomonocytic leukemia (CMML) and myelodysplastic syndrome (MDS) are unknown. We investigated LILRB4 expression in 19 CMML and 27 MDS patients and correlated it with response to subsequent hypomethylating agent (HMA) therapy. LILRB4 RNA expression was increased in CMML patients when compared to MDS patients and healthy controls (q < 0.1) and slightly increased in patients who responded to HMAs (q > 0.1). Pathway analysis revealed upregulation of PD-1 signaling, CTLA-4 signaling, and inflammatory response, and gene correlates were positively associated with CTLA-4 expression. Given current modest results with immunotherapy in myeloid malignancies, further investigation of LILRB4 as an immune checkpoint inhibitor target is needed. With the positive correlation between LILRB4 and CTLA-4 expression, combining anti-LILRB4 and anti-CTLA-4 agents may be a novel therapeutic approach in myeloid malignancies that warrants larger studies.

3.
Cancer Med ; 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32017467

RESUMO

BACKGROUND: Brain metastases are one of the most common intracranial neoplasms. Increasing evidence have indicated that systemic immunotherapy may provide long-term benefits for brain metastases. Herein, we presented the results of an immune oncology panel RNA sequencing platform for patients with brain metastases from different primary sites. METHODS: We investigated 25 samples of human brain metastases from lung cancer (n = 12), breast cancer (n = 6), and colorectal cancer (n = 7). Besides, 13 paired samples of adjacent noncancerous brain tissue (10 from patients with lung cancer and 3 from patients with breast cancer) were collected as controls. By comparing the brain metastases and paired samples of adjacent noncancerous brain tissue from 13 patients, we detected three upregulated and six downregulated genes, representing the malignant properties of cancer cells and increased immune infiltration in the microenvironment. Next, we profiled the immune-related genes in brain metastases from three primary cancer types. RESULTS: A group of genes were significantly overexpressed in the microenvironment of brain metastases from lung cancer, covering the checkpoint pathways, lymphocyte infiltration, and TCR-coexpression. Especially, immune checkpoint molecules, PD-L1, PD-L2, and IDO1 were expressed at higher levels in brain metastases from lung cancer than those from the other two cancer types. CONCLUSIONS: This study presents an immune landscape of brain metastases from different cancer types. With high RNA expression levels of PD-1/PD-L1 axis and immune infiltration in brain metastases, it would be worthwhile to explore the efficacy of immune checkpoint blockade for lung cancer patients with intracranial metastases.

4.
Chaos ; 30(1): 013119, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32013465

RESUMO

Nonlinear dynamical systems often generate significant amounts of observational data such as time series, as well as high-dimensional spatial data. To delineate recurrence dynamics in the spatial data, prior efforts either extended the recurrence plot, which is a widely used tool for time series, to a four-dimensional hyperspace or utilized the network approach for recurrence analysis. However, very little has been done to differentiate heterogeneous types of recurrences in the spatial data (e.g., recurrence variations of state transitions in the spatial domain). Therefore, we propose a novel heterogeneous recurrence approach for spatial data analysis. First, spatial data are traversed with the Hilbert Space-Filling Curve to transform the variations of recurrence patterns from the spatial domain to the state-space domain. Second, we design an Iterated Function System to derive the fractal representation for the state-space trajectory of spatial data. Such a fractal representation effectively captures self-similar behaviors of recurrence variations and multi-state transitions in the spatial data. Third, we develop the Heterogeneous Recurrence Quantification Analysis of spatial data. Experimental results in both simulation and real-world case studies show that the proposed approach yields superior performance in the extraction of salient features to characterize and quantify heterogeneous recurrence dynamics in spatial data.

5.
Reprod Sci ; 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32046389

RESUMO

Anti-Müllerian hormone (AMH) downregulates the level of stem cell factor (SCF) via the cAMP/PKA signaling pathway in human granulosa cells (GCs). Little information is available on the molecular mechanism underlying the interaction. This study is aimed at determining whether AMH regulates expression of SCF via the cAMP-PKA-CREB signaling pathway in human GCs. In the present study, we verified the binding of cAMP-response element-binding protein (CREB) to promoter of SCF in human GCs. Furthermore, the effect of CREB was tested on the SCF promoter, and the site of CREB binding to SCF promoter was identified using truncations as well as assays of SCF-promoted mutation and CREB mutation. To investigate the correlation among AMH, SCF promoter, and CREB, pGL-Basic-SCF+CREB was transfected into overexpressed AMH GCs (AMH-high GCs), low expressed AMH GCs (AMH-low GCs), and normal GCs (GCs), respectively. Finally, immunofluorescence, double immunostaining, and Western blot were carried out in AMH-high and AMH-low GCs to confirm the AMH-mediated regulation of SCF expression by inhibiting the phosphorylation of CREB (pCREB) in GCs. Results indicated CREB interacted with SCF promoter and significantly enhanced the transcription level of SCF. The CREB binding site was localized at 318-321 bp of SCF gene promote. AMH inhibits the expression of SCF by phosphorylation of CREB via the PKA signaling pathway in GCs. These findings provide an in-depth understanding of the molecular mechanism underlying AMH suppressing the follicle growth, which would aid in the development of a novel therapy.

6.
Small ; : e1905223, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32049431

RESUMO

Designing elaborate nanostructures and engineering defects have been promising approaches to fabricate cost-efficient electrocatalysts toward overall water splitting. In this work, a controllable Prussian-blue-analogue-sacrificed strategy followed by an annealing process to harvest defect-rich Ni-Fe-doped K0.23 MnO2 cubic nanoflowers (Ni-Fe-K0.23 MnO2 CNFs-300) as highly active bifunctional catalysts for oxygen and hydrogen evolution reactions (OER and HER) is reported. Benefiting from many merits, including unique morphology, abundant defects, and doping effect, Ni-Fe-K0.23 MnO2 CNFs-300 shows the best electrocatalytic performances among currently reported Mn oxide-based electrocatalysts. This catalyst affords low overpotentials of 270 (320) mV at 10 (100) mA cm-2 for OER with a small Tafel slope of 42.3 mV dec-1 , while requiring overpotentials of 116 and 243 mV to attain 10 and 100 mA cm-2 for HER respectively. Moreover, Ni-Fe-K0.23 MnO2 CNFs-300 applied to overall water splitting exhibits a low cell voltage of 1.62 V at 10 mA cm-2 and excellent durability, even superior to the Pt/C||IrO2 cell at large current density. Density functional theory calculations further confirm that doping Ni and Fe into the crystal lattice of δ-MnO2 can not only reinforce the conductivity but also reduces the adsorption free-energy barriers on the active sites during OER and HER.

7.
J Neuroinflammation ; 17(1): 43, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32005256

RESUMO

BACKGROUND: A hallmark of temporal lobe epilepsy (TLE) is brain inflammation accompanied by neuronal demise. Accumulating evidence demonstrates that Rev-Erbα is involved in regulating neuroinflammation and determining the fate of neurons. Therefore, we studied the expression and cellular distribution of Rev-Erbα in the epileptogenic zone of TLE and the effect of treatment with the Rev-Erbα specific agonist SR9009 in the pilocarpine model. METHODS: The expression pattern of Rev-Erbα was investigated by western blotting, immunohistochemistry, and immunofluorescence labeling in patients with TLE. Next, the effects of SR9009 on neuroinflammation, neuronal apoptosis, and neuronal loss in the mouse hippocampus 7 days after status epilepticus (SE) were assessed by western blotting, immunofluorescence labeling staining, and TUNEL staining. RESULTS: The western blotting, immunohistochemistry, and immunofluorescence labeling results revealed that Rev-Erbα was downregulated in the epileptogenic zone of TLE patients and mainly localized in neurons, astrocytes, and presumably microglia. Meanwhile, the expression of Rev-Erbα was decreased in the hippocampus and temporal neocortex of mice treated with pilocarpine in the early post-SE and chronic phases. Interestingly, the expression of Rev-Erbα in the normal hippocampus showed a 24-h rhythm; however, the rhythmicity was disturbed in the early phase after SE, and this disturbance was still present in epileptic animals. Our further findings revealed that treatment with SR9009 inhibited NLRP3 inflammasome activation, inflammatory cytokine (IL-1ß, IL-18, IL-6, and TNF-α) production, astrocytosis, microgliosis, and neuronal damage in the hippocampus after SE. CONCLUSIONS: Taken together, these results suggested that a decrease in Rev-Erbα in the epileptogenic zone may contribute to the process of TLE and that the activation of Rev-Erbα may have anti-inflammatory and neuroprotective effects.

8.
J Cell Physiol ; 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-32020590

RESUMO

Atherosclerosis is one of the leading causes of morbidity and mortality, mainly due to the immune response triggered by the recruitment of monocytes/macrophages in the artery wall. Accumulating evidence have shown that matrix stiffness and oxidized low-density lipoproteins (ox-LDL) play important roles in atherosclerosis through modulating cellular behaviors. However, whether there is a synergistic effect for ox-LDL and matrix stiffness on macrophages behavior has not been explored yet. In this study, we developed a model system to investigate the synergistic role of ox-LDL and matrix stiffness on macrophage behaviors, such as migration, inflammatory and apoptosis. We found that there was a matrix stiffness-dependent behavior of monocyte-derived macrophages stimulated with ox-LDL. What's more, macrophages were more sensitive to ox-LDL on the stiff matrices compared to cells cultured on the soft matrices. Through next-generation sequencing, we identified miRNAs in response to matrix stiffness and ox-LDL and predicted pathways that showed the capability of miRNAs in directing macrophages fates. Our study provides a novel understanding of the important synergistic role of ox-LDL and matrix stiffness in modulating macrophages behaviors, especially through miRNAs signaling pathways, which could be potential key regulators in atherosclerosis and immune-targeted therapies.

9.
Int J Pharm ; : 119133, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32057887

RESUMO

Polyvinylpyrrolidone (PVP) is capable of forming complexes in aqueous solutions with poorly soluble drugs, dramatically increasing their aqueous solubility and formulating stable aqueous solutions. These self-assembled complexes could potentially be explored as an ocular drug delivery system. This study assumes that these PVP medicine complexes can improve ocular permeation and strengthen the drugs' therapeutic effects. PVP K-17PF (17PF) and naringenin (NAR) could formulate into self-assembly nanocomplexes (17PF-NAR). The optimal formulation featured a 17PF/NAR weight ratio 20:1 with a complexation efficiency of 98.51 ± 0.86 percent, a mean diameter 6.73 ± 0.42 nm, and a polydispersity index 0.254 ± 0.019. This 17PF-NAR nanocomplex ophthalmic solution was stable in well storage at both 4° and 25°C for 12 weeks. The 17PF-NAR nanocomplexes were observed to significantly improve in vitro antioxidant activity and membrane permeation of NAR. The 17PF-NAR nanocomplex ophthalmic solution had good in vitro cellular tolerance and well in vivo tolerated in rabbits. The 17PF-NAR nanocomplexes also demonstrated significant improvement in in vivo intraocular permeation of NAR and in vivo anti-inflammatory efficacy. These results indicated that nanocomplexes based on 17PF have great potential as novel nanoformulations to improve the ocular bioavailability and therapeutic efficacy of poorly water-soluble agents such as NAR.

10.
Medicine (Baltimore) ; 99(5): e19072, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32000457

RESUMO

RATIONALE: Epithelial-myoepithelial carcinoma is an extremely rare, malignant neoplasm that occurs most frequently in the major salivary glands and accounts for approximately 1% of all salivary gland neoplasms. Few reports have described the presence of epithelial-myoepithelial carcinoma in the sinonasal region; hence, the treatment guideline and prognosis remain unclear. PATIENT CONCERNS: We reported a case of a 75-year-old woman with complaint of nasal obstruction and frequent epistaxis for 3 years. During the nasal endoscopic examination, a mass in the left nasal cavity originating from the left nasal septum that caused bleeding on touch was observed. DIAGNOSES: A diagnosis of epithelial-myoepithelial carcinoma was made based on the features of histopathology and immunohistochemistry of the surgical specimens. The patient was treated by surgical removal of the septal mass using the endonasal endoscopic approach. OUTCOMES: In the serial follow-up paranasal sinus imaging and endoscopic inspection, evidence of recurrence was absent for 18 months after surgery. LESSONS: This report highlights a case of epithelial-myoepithelial carcinoma originating from a minor salivary gland in the nasal septum, one of the most unusual locations. Diagnosis of epithelial-myoepithelial carcinoma should be made based on the findings of immunohistochemistry of the operative specimen. Clinicians should consider complete surgical resection as the effective treatment of choice.


Assuntos
Carcinoma/patologia , Mioepitelioma/patologia , Septo Nasal/patologia , Neoplasias das Glândulas Salivares/patologia , Glândulas Salivares Menores/patologia , Idoso , Carcinoma/cirurgia , Diagnóstico Diferencial , Feminino , Humanos , Mioepitelioma/cirurgia , Septo Nasal/cirurgia , Neoplasias das Glândulas Salivares/cirurgia , Glândulas Salivares Menores/cirurgia
11.
J Nurs Manag ; 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32052511

RESUMO

AIM: We employed the job demands-resources model to examine the impacts of job demands and resources on Chinese nurses' mental health and patient safety. BACKGROUND: Employee mental health and patient safety represent important organizational goals in most hospitals. However, their relationships to insomnia, professional resources, and job crafting, as related to the job demands-resources model among nurses, remains unclear. METHODS: A convenience sample of 2095 registered hospital nurses were recruited from 25 provinces of mainland China from June 2019 to July 2019. Data were collected using self-reported questionnaires that included the following instruments: the Chinese version of the Athens Insomnia Scale, the Practice Environment Scale of the Nursing Work Index, and the Job Crafting scale, the Emotional Exhaustion scale, the Utrecht Work Engagement Scale, the General Health Questionnaire, and the Safety Attitudes Questionnaire. RESULTS: The final model confirmed our hypotheses: burnout mediated the relationship between actual job demands and mental health; work engagement mediated the relationship between perceived job resources and attitudes with regard to patient safety; and job crafting enhanced work engagement and practice environment. CONCLUSION: The job demands-resources model was extended based on the nurses' job characteristics and mental health, as well as patient safety. IMPLICATIONS FOR NURSING MANAGEMENT: These findings may contribute to nursing management strategies that encourage employees to prevent burnout, promote work engagement and job crafting, and in turn promote nurses' mental health and patient safety.

12.
FASEB J ; 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32052888

RESUMO

Long non-coding RNAs (lncRNAs) play key roles in various biological processes. However, the roles of lncRNAs in macrophage polarization remain largely unexplored. In this study, thousands of lncRNAs were identified that are differentially expressed in distinct polarized bone marrow-derived macrophages. Among them, Dnmt3aos (DNA methyltransferase 3A, opposite strand), as a known lncRNA, locates on the antisense strand of Dnmt3a. Functional experiments further confirmed that Dnmt3aos were highly expressed in M(IL-4) macrophages and participated in the regulation of Dnmt3a expression, and played a key role in macrophage polarization. The DNA methylation profiles between the Dnmt3aos knockdown group and the control group in M(IL-4) macrophages were determined by MeDIP-seq technique for the first time, and the Dnmt3aos-Dnmt3a axis-mediated DNA methylation modification-regulated macrophage polarization- related gene IFN-γ was identified. Our study will help to enrich our knowledge of the mechanism of macrophage polarization.

13.
J Mol Cell Cardiol ; 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-32006532

RESUMO

Hypertension is an independent risk factor for atrial fibrillation (AF), although its specific mechanisms remain unclear. Previous research has been focused on cyclic stretch, ignoring the role of high hydrostatic pressure. The present study aimed to explore the effect of high hydrostatic pressure stimulation on electrical remodeling in atrial myocytes and its potential signaling pathways. Experiments were performed on left atrial appendages from patients with chronic AF or sinus rhythm, spontaneously hypertensive rats (SHRs) treated with or without valsartan (10 mg/kg/day) and HL-1 cells were exposed to high hydrostatic pressure using a self-developed device. Whole-cell patch-clamp recordings and western blots demonstrated that the amplitudes of ICa,L, Ito, and IKur were reduced in AF patients with corresponding changes in protein expression. Angiotensin protein levels increased and Ang1-7 decreased, while focal adhesion kinase (FAK) and Src kinase were enhanced in atrial tissue from AF patients and SHRs. After rapid atrial pacing, AF inducibility in SHR was significantly higher, accompanied by a decrease in ICa,L, upregulation of Ito and IKur, and a shortened action potential duration. Angiotensin upregulation and FAK/Src activation in SHR were inhibited by angiotensin type 1 receptor inhibitor valsartan, thus, preventing electrical remodeling and reducing AF susceptibility. These results were verified in HL-1 cells treated with high hydrostatic pressure, and demonstrated that electrical remodeling regulated by the FAK-Src pathway could be modulated by valsartan. The present study indicated that high hydrostatic pressure stimulation increases AF susceptibility by activating the renin-angiotensin system and FAK-Src pathway in atrial myocytes.

14.
Nanoscale ; 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32031187

RESUMO

The effect of the pore size of nanoporous gold on electrochemical reduction of functionalized carbonyl compounds was investigated. NPG with a pore size of ∼30 nm significantly enhanced the reactivity with high chemo-selectivity at a low-potential. Typically, p-nitrobenzaldehyde reduction demonstrates a high turnover frequency (TOF) up to 232 000 h-1.

15.
Am J Reprod Immunol ; : e13223, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31972050

RESUMO

The survival and development of a semi-allogeneic fetus during pregnancy require the involvement of a series of cytokines and immune cells. Chemokines are a type of special cytokine those were originally described as having a role in leukocyte trafficking. CXC chemokine ligand (CXCL) 16 is a member of the chemokine family, and CXC chemokine receptor (CXCR) 6 is its sole receptor. Emerging evidence has shown that CXCL16/CXCR6 is expressed at the maternal-fetal interface, by cell types that include trophoblast cells, decidual stroma cells, and decidual immune cells (eg, monocytes, γδT cells, and natural killer T (NKT) cells). The regulation of expression of CXCL16 is quite complex, and this process involves a multitude of factors. CXCL16 exerts a critical role in the establishment of a successful pregnancy through a series of molecular interactions at the maternal-fetal interface. However, an abnormal expression of CXCL16 is associated with certain pathological states associated with pregnancy, including recurrent miscarriage, pre-eclampsia, and gestational diabetes mellitus (GDM). In the present review, the expression and pleiotropic roles of CXCL16 under conditions of physiological and pathological pregnancy are systematically discussed.

16.
Micron ; 130: 102824, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31927410

RESUMO

Immobilization can lead to intervertebral disc degeneration. The biomechanical characteristics of such discs have not so far been investigated at the micro- or nanoscale, the level at which cells sense and respond to the surrounding environment. This study aimed to characterize changes in the elastic modulus of the collagen fibrils in the nucleus pulposus at the nanoscale and correlate this with micro-biomechanical properties of the nucleus pulposus after immobilization, in addition to observation of tissue histology and its gene expressions. An immobilization system was used on the rat tail with an external fixation device. The elastic modulus was measured using both nano and micro probes for atomic force microscopy after 4 and 8 weeks of immobilization. Histology of the tissue was observed following hematoxylin and eosin staining. Gene expression in the annulus fibrosus tissue was quantified using real-time reverse transcription-polymerase chain reaction. The elastic modulus of the collagen fibrils in the nucleus pulposus at the nanoscale increased from 74.07 ± 17.06 MPa in the control to 90.06 ± 25.51 MPa after 8 weeks (P = 0.007), and from 33.51 ± 9.33 kPa to 43.18 ± 12.08 kPa at the microscale (P = 0.002). After immobilization for 8 weeks, a greater number of cells were observed by histology to be aggregated within the nucleus pulposus. Collagen II (P = 0.007) and aggrecan (P = 0.003) gene expression were downregulated whereas collagen I (P = 0.002), MMP-3 (P < 0.001), MMP-13 (P < 0.001) and ADAMTs-4 (P < 0.001) were upregulated. Immobilization not only influenced individual collagen fibrils at the nanoscale, but also altered the micro-biomechanics and cell response in the nucleus pulposus. These results suggest that significant changes occur in intervertebral discs at both scales after immobilization, a situation about which clinicians should be aware when immobilization has to be used clinically.

17.
ACS Appl Mater Interfaces ; 12(4): 4473-4481, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31895534

RESUMO

A proton exchange membrane fuel cell (PEMFC) system with a hydrogen generator could have higher energy density than flexible batteries and supercapacitors and is possible to meet the urgent demand of flexible electronics. However, a flexible PEMFC pack is still not available due to the absence of a flexible hydrogen generator. To solve this problem, we successfully invented a flexible and adaptable hydrogen generator, which was realized by a new bifunctional aerogel catalyst with the abilities of both storing and producing hydrogen. The flexible hydrogen generator can produce hydrogen at room temperature when the device is inverting, bending, and rotating. By combining this flexible hydrogen generator and the unique flexible PEMFC stack of our group, we originally made a highly flexible and adaptable fuel cell pack with a high theoretical energy density (up to 722 Wh·kg-1) and current achieved energy density (135.9 Wh·kg-1). Such a PEMFC pack is highly promising to meet the high demand of flexible electronics.

19.
Anal Chem ; 92(3): 2435-2442, 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-31904935

RESUMO

The process and mechanism of silk degradation is still a bewildering mystery in the investigation and conservation of cultural relics, which rely on the development of accurate and tailored analysis technologies. Here, two advanced approaches, proteomics and immunology, were developed for determining the deterioration behavior of historic silk fabrics and artificially aged samples from the molecular to the holistic level. The surface morphology and secondary structure of silk were destroyed during degradation. Subsequently, the proteomics and immunology analysis demonstrated a new degradation model differing from previous reports. First, the amorphous region and the looser crystalline regions were destroyed together, and the macromolecular chains were broken randomly. Then, the tight ß-sheet blocks in the crystalline region were exposed and deteriorated, which expedited the degradation of tight ß-sheet blocks and relatively loose blocks in the crystalline domain as well as the amorphous domain, ultimately yielding small molecule polypeptides. However, the deterioration process of ancient fabrics could be accelerated by poor burial conditions, thus showing distinct destructive characteristics. Overall, the results gave us a more comprehensive and profound understanding of the degradation process of ancient silk.

20.
J Hazard Mater ; 388: 122058, 2020 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-31951993

RESUMO

Plastic pollution is one of the most serious environmental issues worldwide. The negative influence of plastics on aquatic organisms has increasingly concerned, especially the influence of microplastic (MPs). In the present study, the toxicology of nano-sized MPs (nMPs) and micron-sized MPs (mMPs) were comparatively studied. Goldfish larvae were exposed to 10, 100 and 1000 µg/L nMPs and mMPs for 1, 3 and 7 days. The enrichment of MPs, body length, heart rate, motor ability, microscopic and ultrastructure of intestine, liver, gill and muscle tissue, as well as the oxidative stress were analyzed. Results showed that both 70 nm and 50 µm MPs were accumulated in the digestive tract of larvae. MPs at high concentrations could induce oxidative stress, destroy intestine, liver and gill tissues, increase heart rate, and inhibit growth and swimming speed of the larvae. The most important finding was that nMPs could enter into the muscle tissue through the epidermis of the larvae. It could cause damage to muscle tissue, destroy nerve fibers, inhibit acetylcholinase (AchE) activity, and show great adverse effects on larval movement than mMPs. In conclusion, both nMPs and mMPs at higher concentrations can cause damage to fish larvae and nMPs are potentially more hazardous.

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