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1.
Respir Physiol Neurobiol ; 271: 103290, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31525465

RESUMO

Airway remodeling is a key pathological lesion in chronic obstructive pulmonary disease (COPD), and it leads to poorly reversible airway obstruction. Current pharmacological interventions are ineffective at controlling airway remodeling. To address this issue, we queried the Connectivity Map (cMap) database to screen for drug candidates that had the potential to dilate the bronchus and inhibit airway smooth muscle (ASM) proliferation. We identified ciprofibrate as a drug candidate. Ciprofibrate inhibited cigarette smoke extract-induced rat ASM cell contraction and proliferation in vitro. We exposed Sprague-Dawley (SD) rats to clean air or cigarette smoke (CS) and treated the rats with ciprofibrate. Ciprofibrate improved pulmonary function, inhibited airway hypercontraction, and ameliorated morphological small airway remodeling, including airway smooth muscle proliferation, in CS-exposed rats. Ciprofibrate also significantly reduced IL-1ß, IL-12p70, IL-17A and IL-18 expression, which are related to airway remodeling, in the sera of CS-exposed rats. These findings indicate that ciprofibrate could attenuate airway remodeling in CS-exposed rats.

2.
Carcinogenesis ; 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31784734

RESUMO

Forkhead box D3 (FOXD3), an important member of the forkhead box transcription factor family, has many biological functions. However, the role and signaling pathways of FOXD3 in colorectal cancer (CRC) are still unclear. We examined FOXD3 expression and methylation in normal colon mucosa, CRC cell lines, and primary tumors by RT-PCR, methylation-specific PCR, and bisulfite genomic sequencing. We also evaluated its tumor-suppressive function by examining its modulation of apoptosis under endoplasmic reticulum (ER) stress in CRC cells. The FOXD3 target signal pathway was identified by western blotting, immunofluorescence, and chromatin immunoprecipitation. We found that FOXD3 was frequently methylated and silenced in CRC cell lines and was downregulated in CRC tissues compared with paired adjacent non-tumor tissues. Meanwhile, low FOXD3 protein expression was significantly correlated with poor histopathological grading, lymph node metastasis, and poor prognosis of patients, indicating its potential as a tumor marker that may be of potential value as a therapeutic target for CRC. Moreover, restoration of FOXD3 expression inhibited the proliferation and migration of tumor cells. FOXD3 also increased mitochondrial apoptosis through the unfolded protein response under ER stress. Furthermore, we found that FOXD3 could bind directly to the promoter of p53 and enhance its expression. Knockdown of p53 impaired the effect of apoptosis induced by FOXD3. In conclusion, we showed for the first time that FOXD3, which is frequently methylated in CRC, acted as a tumor suppressor inducing tumor cell apoptosis under ER stress via p53.

3.
Life Sci ; : 117115, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31790685

RESUMO

AIMS: Psoriasis is a cutaneous disease mainly characterized by keratinocyte hyperproliferation, abnormal epidermal differentiation, inflammation and angiogenesis. In this study, we aimed to report the therapeutic potential of Diosgenin on psoriasis-like models and explore the underlying mechanisms. MAIN METHODS: For in vitro studies, we initially evaluated the bioeffects of Diosgenin on keratinocytes by detecting the cell viability, cell cycle and apoptosis in HaCaT cells. To mimic psoriatic conditions, we established hyperproliferative model by stimulating HaCaT cells with LPS/IL-22 and inflammatory model by LPS/TNF-α stimulation. Meanwhile, differentiation in HaCaT cells and angiogenesis in HUVECs/HMEC-1 were observed. The influence of Diosgenin on above-mentioned conditions was examined. For in vivo studies, we dosed imiquimod (IMQ) -induced mice with Diosgenin and conducted hematoxylin-eosin (HE), TUNEL assay and immunohistochemistry (IHC) to evaluate histological changes, apoptosis and the status of keratinocyte proliferation, epidermal differentiation, vascularity and cutaneous inflammatory cell infiltration respectively. KEY FINDINGS: Results showed that Diosgenin inhibited HaCaT cell growth through cell cycle arrest and NFκB inhibition while induced apoptosis by regulating Caspase3, Bax and Bcl-2 protein expression. After Diosgenin treatment, NFκB nuclear translocation and IL-22 receptor dependent pathways were suppressed in LPS/IL-22 induced HaCaT cells respectively. Furthermore, Diosgenin downregulated proinflammatory cytokines through TLR4/Myd88 inhibition and upregulated several differentiation markers' expression in HaCaT cells. Additionally, Diosgenin inhibited vascular formation partially by reducing the VEGF-α expression in keratinocytes. In animal studies, Diosgenin attenuated psoriatic lesions on mice accordingly. SIGNIFICANCE: This study suggests that Diosgenin might be a promising candidate for developing anti-psoriatic agents.

4.
Clin Endosc ; 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31794655

RESUMO

Background/Aims: Endoscopic ultrasonography (EUS)-guided drainage is the preferred approach for infected or symptomatic pancreatic fluid collections (PFCs). Here, we developed an algorithm for the management of pancreatitis complicated by PFCs and report on its efficacy and safety. Methods: Between September 2011 and October 2017, patients were prospectively managed according to the algorithm. PFCs were classified as poorly organized fluid collections (POFCs), pancreatic pseudocysts (PPs), or walled-off pancreatic necrosis (WOPN). Clinical success was defined as a decrease in PFC size by ≥50% of the maximal diameter or to ≤2 cm. Results: A total of 108 patients (62% male; mean age, 53 years) were included: 13 had POFCs, 43 had PPs, and 52 had WOPN. Seventy-two patients (66%) required a pancreatic duct (PD) stent, whereas 65 (60%) received enteral feeding. A total of 103 (95%) patients achieved clinical success. Eight patients experienced complications including bleeding (n=6) and surgical intervention (n=2). Patients with enteral feeding were 3.4 times more likely to achieve resolution within 60 days (p=0.0421), whereas those with PD stenting was five times more likely to achieve resolution within 90 days (p=0.0069). Conclusions: A high PFC resolution rate can be achieved when a dedicated algorithm encompassing EUS-guided drainage, PD stenting, and early enteral feeding is adopted.

5.
Clin Endosc ; 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31794656

RESUMO

Superior mesenteric artery syndrome (SMAS) causes compression and partial or complete obstruction of the duodenum, resulting in abdominal pain, nausea, vomiting, and weight loss. If conservative therapy fails, the patient is typically referred for enteral feeding or laparoscopic gastrojejunostomy. The last few years have seen increasing use of endoscopic ultrasound-guided gastrojejunostomy (EUS-GJ) for gastric obstruction indications. EUS-GJ involves the creation of a gastric bypass via an echoendoscope in cases in which the small intestine can be punctured under ultrasonographic visualization, resulting in an incision-free, efficient, and safe procedure. In this case report, we present the first case of SMAS treated using a reverse EUS-GJ, and describe the steps and advantages of the procedure in this particular case.

6.
Lipids Health Dis ; 18(1): 210, 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31801554

RESUMO

BACKGROUND: It has been confirmed that the triglyceride to high-density lipoprotein cholesterol ratio (THR) is associated with insulin resistance and metabolic syndrome. However, to the best of our knowledge, only a few studies with small sample sizes have investigated the relationship between THR and coronary artery disease (CAD). Therefore, we aimed to assess the correlation between the THR and long-term mortality in patients with CAD after undergoing percutaneous coronary intervention (PCI) in our study that enrolled a large number of patients. METHODS: A total of 3269 post-PCI patients with CAD were enrolled in the CORFCHD-ZZ study from January 2013 to December 2017. The mean follow-up time was 37.59 ± 22.24 months. Patients were divided into two groups according to their THR value: the lower group (THR < 2.84, n = 1232) and the higher group (THR ≥ 2.84, n = 2037). The primary endpoint was long-term mortality, including all-cause mortality (ACM) and cardiac mortality (CM). The secondary endpoints were major adverse cardiac events (MACEs) and major adverse cardiac and cerebrovascular events (MACCEs). RESULTS: In our study, ACM occurred in 124 patients: 30 (2.4%) in the lower group and 94 (4.6%) in the higher group (P = 0.002). MACEs occurred in 362 patients: 111 (9.0%) in the lower group and 251 (12.3%) in the higher group (P = 0.003). The number of MACCEs was 482: 152 (12.3%) in the lower group and 320 (15.7%) in the higher group (P = 0.008). Heart failure occurred in 514 patients: 89 (7.2%) in the lower group and 425 (20.9%) in the higher group (P < 0.001). Kaplan-Meier analyses showed that elevated THR was significantly related to long-term ACM (log-rank, P = 0.044) and the occurrence of heart failure (log-rank, P < 0.001). Multivariate Cox regression analyses showed that the THR was an independent predictor of long-term ACM (adjusted HR = 2.042 [1.264-3.300], P = 0.004) and heart failure (adjusted HR = 1.700 [1.347-2.147], P < 0.001). CONCLUSIONS: An increased THR is an independent predictor of long-term ACM and heart failure in post-PCI patients with CAD.

7.
Orthop Surg ; 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31721459

RESUMO

OBJECTIVES: To evaluate treatments and prognostic factors for the myxoid liposarcoma in extremities. METHODS: We retrospectively reviewed 34 patients histologically diagnosed with myxoid liposarcoma arising in the extremities, treated in our hospital from 2010 to 2017. We recorded tumor locations, max diameter, operations, complications, radiation, chemotherapy, survival, recrudescence, and metastases. Overall survival, treatments, and prognostic factors were subsequently analyzed. RESULTS: The mean age of 34 patients with myxoid liposarcoma in extremities was 49.1 years, and the mean follow-up period was 65.1 months. The median survival time was 190 months. Five of 14 patients accepted recrudescence resection and two patients of 20 patients who underwent primary tumor resection or unplanned operation died of tumor progression. Although no statistical difference was found (X 2 = 3.331, P = 0.068), the lower mortality was confirmed in the patients who accepted primary tumor resection or unplanned operation. Eleven patients with a tumor diameter of 8.6 ± 4.7 cm accepted wide resection, while 23 patients with 17.2 ± 8.8 cm tumors accepted marginal resection. Statistical difference was found between the size of tumors with relatively wide resection and those with relatively marginal resection (F = 9.130, P = 0.005). No recurrence or metastasis occurred in patients who accepted wide resection, while 14 patients presented with local recurrence and 8 patients developed distant metastases among the 23 patients with marginal resection. Seven patients died of metastases, while one patient lived with metastases. No significant difference in survival was found between different surgical methods (X 2 = 0.9460, P = 0.3307). The average diameter of eight patients with distant metastases was 21.7 cm, which was considerable larger than the 12.1 cm of patients without metastasis. This difference was proven significant upon the statistical analysis (F = 9.412, P = 0.004). CONCLUSIONS: Wide resection achieved good local control but was not unambiguously superior in long-term survival. Myxoid liposarcoma tumors with larger diameters were more difficult to be submitted to wide resection and were more likely to present with distant metastasis.

8.
J Orthop Surg Res ; 14(1): 352, 2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31706336

RESUMO

BACKGROUND: Aseptic loosening has become the main cause of prosthetic failure in medium- to long-term follow-up. The objective of this study was to establish and validate a nomogram model for aseptic loosening after tumor prosthetic replacement around knee. METHODS: We collected data on patients who underwent tumor prosthetic replacements. The following risk factors were analyzed: tumor site, stem length, resection length, prosthetic motion mode, sex, age, extra-cortical grafting, custom or modular, stem diameter, stem material, tumor type, activity intensity, and BMI. We used univariate and multivariate Cox regression for analysis. Finally, the significant risk factors were used to establish the nomogram model. RESULTS: The stem length, resection length, tumor site, and prosthetic motion mode showed a tendency to be related to aseptic loosening, according to the univariate analysis. Multivariate analysis showed that the tumor site, stem length, and prosthetic motion mode were independent risk factors. The internal validation indicated that the nomogram model had acceptable predictive accuracy. CONCLUSIONS: A nomogram model was developed for predicting the prosthetic survival rate without aseptic loosening. Patients with distal femoral tumors and those who are applied with fixed hinge and short-stem prostheses are more likely to be exposed to aseptic loosening.

9.
Ultrason Sonochem ; 61: 104815, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31710999

RESUMO

Zinc tungstate (ZnWO4) was previously used as a photocatalyst. In this paper, for the first time as an sonocatalyst, the performance of ZnWO4 for sonocatalytic degradation of meloxicam (MEL) under ultrasonic irradiation were studied. Firstly, ZnWO4 nanomaterials were synthesized at different acidity (pH = 5, 6, 7, 8, 9) via the hydrothermal method. Utilizing SEM, XRD and EDS techniques to characterize composition and morphology of each product, the same crystal forms, but different morphologies (nano-sheet, nano-microspheres or nano-rod) of ZnWO4 could be obtained. Secondly, the sonocatalytic activities of ZnWO4 on degradation of MEL were studied. It was found that the degradation ratio varied with the synthetic pH values, with ZnWO4 under synthetic pH = 6 exhibiting the best sonocatalytic performance (75.7%). Whilebeing synthesized at this pH value, ZnWO4nano-microspheres had the largest BET surface area (27.068 m2/g), the smallest particle size (40-60 nm) so as to provide more active sites on its surface, which were able to produce more reactive oxygen species (ROS) and holes under ultrasonic irradiation. These ROS and holes had a positive effect on the degradation of MEL into CO2, H2O and inorganic. Thirdly, various influential factors including ultrasonic power intensity, ultrasonic time, catalyst addition dosage, initial concentration of MEL solution and reusability of catalyst were also explored. Under the condition of 10 mg/L MEL concentration, 20 mg catalyst dosage, 120 min irradiation time, 0.278 W/cm2 ultrasonic power intensity, the degradation ratio on MEL reached 75.7%. Finally, the presence of hydroxyl radical (OH) and singlet molecular oxygen (1O2) in the reaction was confirmed by adding ROS scavenger. The experimental results suggested that ZnWO4 nanoparticle could be used not only as an effective photocatalyst, but also, under the condition of ultrasonic irradiation, a promising sonocatalyst for degradation of organic pollutants in aqueous media.

10.
Sci Rep ; 9(1): 16539, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31719569

RESUMO

Nowadays, early oral feeding after gastrectomy has been gradually accepted and applied in the clinical practice, but there is still no specific uniform feeding regimen available which works best for patients in different regions with different races and eating habits. Aiming to establish an early oral feeding schedule suitable for local Chinese patients after gastric surgery, from May 2014 to May 2018, 87 gastric cancer patients undergoing various types of gastric resections were enrolled in an early feeding protocol and their clinical course was reviewed retrospectively. A stepwise, local patient-specific, early oral feeding schedule was proposed, implemented within an early recovery after surgery (ERAS) protocol and accessed in terms of its safety and tolerability. The primary surgical outcomes included: a median (interquartile range; IQR) postoperative hospital stay of 6 (3) days; 67 (77%) patients were well tolerant of this schedule from postoperative day (POD) 1 to POD 4; 20 (23%) patients had mild I/II grade complications (Clavien-Dindo classification); 3 (3%) patients had IIIB complications, zero cases of hospital mortality. Compared to similar studies in the past, our early oral feeding program is also safe and beneficial, and it can shorten the postoperative hospital stay without causing any increase in postoperative complications. In summary, our work herein reported the establishment of a detailed early oral feeding schedule embedded within an ERAS protocol which was found to be suitable for local Chinese patients after gastric surgery. Accordingly, this early oral feeding schedule is worth further research and promotion.

12.
Asian J Androl ; 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31736475

RESUMO

Phosphoribosyl-pyrophosphate synthetase 2 (PRPS2) is a rate-limiting enzyme and plays an important role in purine and pyrimidine nucleotide synthesis. Recent studies report that PRPS2 is involved in male infertility. However, the role of PRPS2 in hypospermatogenesis is unknown. In this study, the relationship of PRPS2 with hypospermatogenesis and spermatogenic cell apoptosis was investigated. The results showed that PRPS2 depletion increased the number of apoptotic spermatogenic cells in vitro. PRPS2 was downregulated in a mouse model of hypospermatogenesis. When PRPS2 expression was knocked down in mouse testes, hypospermatogenesis and accelerated apoptosis of spermatogenic cells were noted. E2F transcription factor 1 (E2F1) was confirmed as the target gene of PRPS2 and played a key role in cell apoptosis by regulating the P53/Bcl-xl/Bcl-2/Caspase 6/Caspase 9 apoptosis pathway. Therefore, these data indicate that PRPS2 depletion contributes to the apoptosis of spermatogenic cells and is associated with hypospermatogenesis, which may be helpful for the diagnosis of male infertility.

13.
Int J Mol Sci ; 20(23)2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31779098

RESUMO

Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a key role in cholesterol homeostasis and atherogenesis. However, there are only limited rodent models, with a functional low-density lipoprotein receptor (LDLR) pathway and cholesteryl ester transfer protein (CETP) to evaluate the drug candidates targeting the PCSK9/LDLR pathway, that are translatable to humans. Here, by using our recently generated LDLR heterozygote (Ldlr+/-) hamster model with functional LDLR pathway and CETP function, we seek to evaluate the effect of a PCSK9 antibody, evolocumab, on dyslipidemia and atherosclerosis compared with ezetimibe, an effective inhibitor of cholesterol absorption, as a positive therapeutic control. We show that the plasma levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) were significantly increased in Ldlr+/- hamsters fed a high-fat high-cholesterol (HFHC) diet; therefore, areas of atherosclerotic lesion in the aorta were obviously increased and positively correlated with plasma LDL-C and TC. Circulating free PCSK9 was downregulated by the HFHC diet and was undetectable in the evolocumab treated group, as expected. Most importantly, either evolocumab or ezetimibe treatment prevented HFHC diet-induced hyperlipidemia and subsequent atherosclerotic plaque formation. The results indicate that Ldlr+/- hamsters fed an HFHC diet represent an ideal rodent model to evaluate drug candidates that affect LDLR pathways.

14.
Artigo em Inglês | MEDLINE | ID: mdl-31703990

RESUMO

Four anthracene-based dyes (AN-3, AN-11, AN-12, AN-14) are investigated with density functional theory (DFT) and time-dependent density functional theory (TD-DFT) for dye-sensitized solar cells (DSSCs), involving the stable molecular geometries, the electronic structures, the absorption and fluorescence spectra, and the performance of photoelectric properties. For the simulation of the realistic environment, some important parameters, including energy levels, energy gaps, electron density, projected density of states (PDOS), absorption, vertical dipole moment, first hyperpolarizability, light-harvesting efficiency (LHE), evaluation on electron injection, are calculated for each dye molecule. The relevant electron transfer (ET) and dynamic processes were studied by using the charge different density (CDD) and Newns-Anderson model. The relationship between structure and performance are established. Furthermore, six dyes are designed and examined on the basis of AN-11 to improve optical response and electron injection. It is expected that this study will give theoretical guidance and ideas for finding potential solar cell materials.

15.
J Zhejiang Univ Sci B ; 20(12): 983-994, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31749345

RESUMO

Genome sequencing projects revealed massive cryptic gene clusters encoding the undiscovered secondary metabolites in Streptomyces. To investigate the metabolic products of silent gene clusters in Streptomyces chattanoogensis L10 (CGMCC 2644), we used site-directed mutagenesis to generate ten mutants with point mutations in the highly conserved region of rpsL (encoding the ribosomal protein S12) or rpoB (encoding the RNA polymerase ß-subunit). Among them, L10/RpoB (H437Y) accumulated a dark pigment on a yeast extract-malt extract-glucose (YMG) plate. This was absent in the wild type. After further investigation, a novel angucycline antibiotic named anthrachamycin was isolated and determined using nuclear magnetic resonance (NMR) spectroscopic techniques. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis and electrophoretic mobility shift assay (EMSA) were performed to investigate the mechanism underlying the activation effect on the anthrachamycin biosynthetic gene cluster. This work indicated that the rpoB-specific missense H437Y mutation had activated anthrachamycin biosynthesis in S. chattanoogensis L10. This may be helpful in the investigation of the pleiotropic regulation system in Streptomyces.

16.
Bioorg Chem ; : 103389, 2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31753312

RESUMO

Numerous post-translational modifications (PTMs) of the Parkinson's disease (PD) associated α-synuclein (α-syn) protein have been recognised to play critical roles in disease aetiology. Indeed, dysregulated phosphorylation and proteolysis are thought to modulate α-syn aggregation and disease progression. Among the PTMs, enzymatic glycosylation with N-acetylglucosamine (GlcNAc) onto the protein's hydroxylated amino acid residues is reported to deliver protective effects against its pathogenic processing. This modification has been reported to alter its pathogenic self-assembly. As such, manipulation of the protein's O-GlcNAcylation status has been proposed to offer a PD therapeutic route. However, targeting upstream cellular processes can lead to mechanism-based toxicity as the enzymes governing O-GlcNAc cycling modify thousands of acceptor substrates. Small glycopeptides that couple the protective effects of O-GlcNAc with the selectivity of recognition sequences may prove useful tools to modulate protein aggregation. Here we discuss efforts to probe the effects of various O-GlcNAc modified peptides on wild-type α-synuclein aggregation.

17.
Orthop Surg ; 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31755239

RESUMO

OBJECTIVE: To observe the process of sacroiliac joint invasion by primary malignant tumors of sacrum and iliac bone, and to explore the methods of surgical resection and reconstruction. METHODS: From January 2009 to November 2017, there were nine patients with primary malignant bone tumors involving sacroiliac joints, five males and four females, aged from 16 to 63 years, with an average age of 35 years. Of these there were three cases of primitive neuroectodermal tumors, three cases of chondrosarcoma, and three cases of osteosarcoma. Pelvic ring reconstruction was performed with longitudinal half sacrum, sacroiliac joint and partial iliac bone block excision and screw-rod system combined with bone grafting. RESULTS: The operation time was 155-310 min, with an average of 245 ± 55 min, and the bleeding volume was 1400-8500 ml, with an average of 3111 ± 2189 ml. Follow-up ranged from 5 to 108 months, with a median follow-up of 24 months. Three patients (33.3%) had local recurrence, three patients (33.3%) survived without tumors, and one patient had lung metastasis 2 years after operation, and survived with tumors. Five patients (55.6%) died, of which four died of lung metastasis and one died of brain metastasis. Survival analysis showed that the 3-year overall survival rate was 57%. Bone grafts did not heal in four patients, and bone grafts healed in five patients. The healing time ranged from 5 to 7 months, with an average of 6.2 months. COMPLICATIONS: one patient developed deep infection 2 months after operation; one patient had skin edge necrosis; titanium rod loosening and displacement were found in two patients with nonunion of bone graft, and no fracture of nail rod was found. The MSTS 93 functional score of nine patients ranged from 20% to 50%, with an average of 34%. CONCLUSION: The tumors around the sacroiliac joint often invade the contralateral bone by ligament, and the en bloc resection and pelvic ring reconstruction for primary malignant bone tumors involving sacroiliac joint was feasible.

18.
Part Fibre Toxicol ; 16(1): 46, 2019 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-31775802

RESUMO

BACKGROUND: Silver nanoparticles (AgNPs), as promising anti-microbials and anti-cancer therapeutics, the toxicological effect and killing efficiency towards cells need in-depth investigation for better applications in daily life and healthcare fields. Thus far, limited studies have yet elucidated the protein targets of AgNPs and silver ions (Ag+) released from intracellular AgNPs dissolution in hepatocytes, as well as potential interaction mechanism. RESULTS: Through integrating proteomic and metallomic methodologies, six intracellular protein targets (i.e. glutathione S-transferase (GST), peroxiredoxin, myosin, elongation factor 1, 60S ribosomal protein and 40S ribosomal protein) were ultimately identified and confirmed as AgNPs- and Ag+ -binding proteins. Toward a deep understanding the direct interaction mechanism between AgNPs and these protein targets, GST was chosen as a representative for toxicological investigation. The results revealed that AgNPs could remarkably deplete the enzyme activity of GST but did not depress the expressions, resulting in elevated intracellular oxidative stress and cell death. Finally, both "Ag+ effect" and "particle-specific effect" were demonstrated to concomitantly account for the overall cytotoxicity of AgNPs, and the former relatively contributed more via activity depletion of GST. CONCLUSIONS: Collectively, our major contribution is the development of an efficient strategy to identify the intracellular AgNPs-targeted protein (e.g. GST) through integrating proteomic and metallomic methodologies, which is helpful to accelerate the interpretation of underlying toxicological mechanism of AgNPs.

19.
Chemistry ; 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31705556

RESUMO

Multi-component tungsten carbide-based hybrid materials featuring different heteroatom dopants coated with X,N dual-doped carbon layers (X/W2 C@X,N-C, XWXNC) were prepared by selecting Keggin-type polyoxometalates (POMs) (NH4 )n [XW12 O40 ] (X=Co, Si, Ge, B, and P) and dicyandiamide (DCA) as precursors. The electrocatalytic activity of these nanocomposites as counter electrode (CE) catalysts for dye-sensitized solar cells (DSSCs) was systematically investigated. Structure characterizations show that X,N heteroatoms were successfully introduced into the W2 C and carbon frameworks. The obtained X,N dual-doped carbon layers were modified and loaded with W2 C nanoparticles, promoting the improvement of catalytic performance by a synergistic effect. The consequence of photoelectric conversion efficiency (PCE) is CoWCoNC (6.68 %)>SiWSiNC (6.56 %)>GeWGeNC (6.49 %)>BWBNC (6.45 %)>PWPNC (6.20 %)>WNC (6.05 %). With the increase in electronegativity of the dopants, the photovoltaic performance decreases in a reverse order. This work provides a shortcut to the rational design of highly efficient and cost-effective catalysts for DSSCs.

20.
Int J Biol Macromol ; 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31756484

RESUMO

In this study, an endophytic actinobacterium Glutamicibacter halophytocola KLBMP 5180, was investigated for the production and antioxidant activity of exopolysaccharides (EPSs). First, the suitable fermentation time, temperature, inoculation volume, pH value, and the carbon and nitrogen sources for EPSs production were obtained using the one variable at a time method (OVAT). Then, a central composition design was used for fermentation conditions optimization to obtain the maximum EPS yield. The optimal medium and condition were as follows: 100 mL broth in 250 mL Erlenmeyer flasks, including 3.65 g/L maltose, 9.88 g/L malt extract, 3.40 g/L yeast extract, 1.41 g/L MnCl2, pH 7.5, culture temperature 28 °C, and 200 rpm for 7 days, which increased the yield of EPSs to 2.89 g/L. Two purified EPSs, 5180EPS-1 (MW 58.9 kDa) and 5180EPS-2 (10.5 kDa), comprising rhamnose, galacturonic acid, glucose, glucuronic acid, xylose, and arabinose, were obtained for chemical analysis and antioxidant evaluation. The scavenging ability and reducing power of the superoxide anion and hydroxyl radicals demonstrated the moderate in vitro antioxidant activities of the two EPSs, thus indicating their potential to be a new source of natural antioxidants. However, further structure elucidation and functional studies need to be continued.

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