This paper proposes a novel transformerless grid-connected power converter with negative grounding for a photovoltaic generation system. The negative terminal of the solar cell array can be directly ...connected to the ground in the proposed grid-connected power converter to avoid the transparent conducting oxide corrosion that occurs in some types of thin-film solar cell array. The proposed grid-connected power converter consists of a dc-dc power converter and a dc-ac inverter. The salient features of the proposed power converter are that some power electronic switches are simultaneously used in both the dc-dc power converter and dc-ac inverter, and only two power electronic switches operate at high switching frequency at the same time (one is in the dc-dc power converter and the other is in the dc-ac inverter). The leakage current of the photovoltaic generation system is reduced because the negative terminal of the solar cell array is connected directly to the ground. Finally, a prototype was developed to verify the performance of the proposed grid-connected power converter. The experimental results show that the performance of the proposed grid-connected power converter is as expected.
The influence of riboflavin (B
2
)–overproducing lactobacilli on the antioxidant status, isoflavone conversion, off-flavor reduction, amino acid profile, and viscosity of B
2
-bio-enriched fermented ...soymilk was investigated. Results showed that B
2
in fermented soymilk was notably increased from 0.2 to 3.8 μg/mL for
Lactobacillus fermentum
UFG169 and to 1.9 μg/mL for
Lactobacillus plantarum
UFG10. The apparent viscosity significantly changed with rising acidity and agglutination of protein. The off-flavor volatile substances (hexanal and nonanal) were significantly reduced in fermented soymilk. Furthermore, a large amount of glucoside form isoflavones was deglycosylated into bioactive aglycones after 4 h up to 32 h. B
2
content and isoflavones significantly improved the antioxidant status of soymilk. Partial least squares regression analysis correlated the strain activity and fermentation time with the improved nutritional and functional soymilk qualities. This study demonstrated the strategy for strain development for B
2
-bio-enriched fermentation to extend the health-promoting benefits of soymilk and soy-related foods.
Key points
• B
2
-enriched fermentation enhanced the nutrition and functional status of soymilk.
• Fermentation time significantly affected the apparent viscosity of fermented soymilk.
• Off-flavor volatile substances were significantly reduced or even diminished.
• Increased B
2
and bioactive isoflavones contributed to improved antioxidant potential.
In addition to the well-known cardiotonic effects, cardiac glycosides (CGs) produce potent anticancer effects with various molecular mechanisms. We previously show that ouabain induces autophagic ...cell death in human lung cancer cells by regulating AMPK-mediated mTOR and Src-mediated ERK1/2 signaling pathways. However, whether and how AMPK and Src signaling interacts in ouabain-treated cancer cells remains unclear. Given the pivotal role of AMPK in metabolism, whether ouabain affects cancer cell metabolism remains elusive. In this study we showed that treatment with ouabain (25 nM) caused simultaneous activation of AMPK and Src signaling pathways in human lung cancer A549 cells and human breast cancer MCF7 cells. Cotreatment with AMPK inhibitor compound C or siRNA greatly abrogates ouabain-induced Src activation, whereas cotreatment with Src inhibitor PP2 has little effect on ouabain-induced AMPK activity, suggesting that AMPK served as an upstream regulator of the Src signaling pathway. On the other hand, ouabain treatment greatly depletes ATP production in A549 and MCF7 cells, and supplement of ATP (100 μM) blocked ouabain-induced AMPK activation. We further demonstrated that ouabain greatly inhibited the mitochondrial oxidative phosphorylation (OXPHOS) in the cancer cells, and exerted differential metabolic effects on glycolysis depending on cancer cell type. Taken together, this study reveals that the altered cancer cell metabolism caused by ouabain may contribute to AMPK activation, as well as its cytotoxicity towards cancer cells.
Fabrication of high-performance and multiple-function conductive polymer composites with uniform distribution and high content of carbon-based nanofillers has been a formidable challenge. In this ...study, a new strategy was introduced to fabricate polyoxymethylene (POM)/multi-walled carbon nanotube (MWCNT) and POM/graphene nanoplate (GNP) composites (PMCNT and PMGNP, respectively), with uniform distributions and high contents of MWCNT and GNP, by assisting of miscible poly(l-lactide) (PLLA). As expected, the composites exhibit robust electromagnetic interference (EMI) shielding, Joule heating, thermal conductivity, and anti-dripping performance. Specifically, the EMI shielding effectiveness of PMCNT40 (with 40 wt% MWCNT) and PMGNP48 (with 48 wt% GNP) reached 45.7 and 44.7 dB with 0.15 mm in thickness. The high electrical and through plane thermal conductivities were 3484 S/m and 1.95 Wm−1K−1, respectively, for PMCNT40, and the corresponding values for PMGNP48 were 2695 S/m and 4.24 Wm−1K−1, respectively. Furthermore, the fabricated composites achieved excellent Joule heating performance, resulting in increases in surface temperature increase to 101.4 °C and 107.6 °C rapidly at the driving voltages of 3.0 V (in case of PMCNT40) and 6.0 V (in case of PMGNP48), respectively. In addition, the composites exhibited excellent solvent resistance and anti-dripping performance, indicating high potential applicability in extreme environments.
Display omitted
•Conductive POM film with high filler loadings was fabricated by PLLA assisting.•Uniform distribution of conductive fillers was achieved in POM matrix.•The 150 μm-thick PMCNT40 film showed an excellent EMI SE of 45.7 dB.•The in-plane thermal conductivity were 36.35 Wm−1K−1 in the PMGNP48 films.•The films also showed robust Joule heating and anti-dripping performance.
To determine the efficacy of acupuncture for hypertension.
Seven electronic databases were searched on April 13, 2014 to include eligible randomized controlled trials (RCTs). Data were extracted and ...risk of bias was assessed. Subgroup analyses and meta- analysis were performed.
23 RCTs involving 1788 patients were included. Most trials had an unclear risk of bias regarding allocation concealment, blinding, incomplete outcome data and selective reporting. Compared with sham acupuncture plus medication, a meta-analysis of 2 trials revealed that acupuncture as an adjunct to medication was more effective on systolic (SBP) and diastolic (DBP) blood pressure change magnitude (n=170, SBP: mean difference (MD)= -7.47,95% confidence intervals (CI):-10.43 to -4.51,I2 =0%; DBP: -4.22,-6.26 to -2.18, 0%).A subgroup analysis of 4 trials also showed acupuncture combined with medication was superior to medication on efficacy rate (n=230, odds ratio (OR)=4.19, 95%CI: 1.65 to 10.67, I2 =0%). By contrast, compared with medication, acupuncture alone showed no significant effect on SBP /DBP after intervention and efficacy rate in the subgroup analysis. (7 trials with 510 patients, SBP: MD=-0.56, 95%CI:-3.02 to 1.89,I2 =60%; DBP: -1.01,-2.26 to 0.24, 23%; efficacy rate: 10 trials with 963 patients, OR=1.14, 95% CI: 0.70 to 1.85, I2 =54%).Adverse events were inadequately reported in most RCTs.
Our review provided evidence of acupuncture as an adjunctive therapy to medication for treating hypertension, while the evidence for acupuncture alone lowing BP is insufficient. The safety of acupuncture is uncertain due to the inadequate reporting of it. However, the current evidence might not be sufficiently robust against methodological flaws and significant heterogeneity of the included RCTs. Larger high-quality trials are required.
Display omitted
•The protonation state of chitosan and the π-π stacking between DOX are important.•The strength of DOX binding to chitosan is balanced by the self-aggregation of DOX.•DOX can ...gradually release from the dispersed chitosan once the pH becomes acidic.
Doxorubicin (DOX) is a broad-spectrum anti-tumor drug, but it has certain limitations in its therapeutic effects due to poor tumor selectivity. Chitosan-based pH-sensitive polymers drug delivery systems could improve DOX’s activity and selectivity against tumor cells. Understanding the atomic interaction mechanism between chitosan and DOX at different pH levels is important in the design and application of chitosan-based drug delivery systems. In this study, molecular dynamics simulations were performed to investigate the encapsulation and release of DOX by chitosan at different pH levels. Our results show that the protonation state of amine groups of chitosan and the π-π stacking interaction between the conjugated anthraquinone ring of DOX regulate the interaction behavior between chitosan and DOX. Moreover, DOX could gradually release from chitosan at acidic pH environment in tumor tissue. These results revealed the underlying atomic interaction mechanism between DOX and chitosan at various pH levels and may provide novel ideas for the design and application of chitosan-based drug delivery system.
Conductive polymer composites have attracted attention for their tunable electrical conductivity and microwave shielding performance by controlling the distribution of conductive fillers. In this ...work, the effect of processing temperature on the distribution of multiwall carbon nanotubes (MWCNTs) in the high density polyethylene/poly(ethylene‐co‐1‐octene) (HDPE/POE) composites was investigated. The MWCNTs were premixed with HDPE to form HDPE/MWCNT master batches at 180°C, and then mixed with POE at different temperature of 140°C and 210°C. At high temperature of 210°C, the volume diffusion of MWCNTs would easily happen in the composites which made the MWCNTs be randomly dispersed in both HDPE and POE domains. At low temperature of 140°C, the MWCNTs could hardly diffuse from HDPE phase to POE phase because of the high viscosity of polymer matrix. Therefore, most of MWCNTs were confined dispersion in HDPE in the composites being prepared at low temperature, which exhibited high electromagnetic interference (EMI) shielding performance and high conductivity. Specifically, the electrical conductivity of the HDPE/POE (58/42 v/v)/MWCNTs composites with 2.5 vol% MWCNTs increased from 7.4 × 10−2 to 0.78 S/m at the mixing temperature of 210°C and 140°C, respectively. The average EMI shielding effectiveness (SE) of the HDPE/POE (58/42 v/v)/MWCNTs composites with 4.0 vol% MWCNTs increased from approximately 19.7 to approximately 26.7 dB at the mixing temperature of 210°C and 140°C, respectively. This works provide a processing temperature controlling strategy to fabricate conductive polymer composites with high‐performance microwave shielding.
A nickel(II)/diamine‐catalyzed diastereo‐ and enantioselective Michael/hemiacetalization cascade reaction of α‐ketoesters with 2‐(2‐nitrovinyl)phenols has been established, thus providing a range of ...structurally diverse polysubstituted chromanes in good yields and excellent stereoselectivities (up to 89% yield, >20:1 dr, >99% ee). Moreover, the gram‐scale experiment was performed with only 0.5 mol% of catalyst, and tricyclic furanobenzodihydropyran compound was gained by the derivatization of product, which showed the great synthetic potential of this strategy.
Testicular dysfunction (TDF) is characterized by testosterone deficiency and is caused by oxidative stress injury in Leydig cells. A natural fatty amide named N-benzylhexadecanamide (NBH), derived ...from cruciferous maca, has been shown to promote testosterone production. Our study aims to reveal the anti-TDF effect of NBH and explore its potential mechanism in vitro. This study examined the effects of H
O
on cell viability and testosterone levels in mouse Leydig cells (TM3) under oxidative stress. In addition, cell metabolomics analysis based on UPLC-Q-Exactive-MS/MS showed that NBH was mainly involved in arginine biosynthesis, aminoacyl-tRNA biosynthesis, phenylalanine, tyrosine and tryptophan biosynthesis, the TCA cycle and other metabolic pathways by affecting 23 differential metabolites, including arginine and phenylalanine. Furthermore, we also performed network pharmacological analysis to observe the key protein targets in NBH treatment. The results showed that its role was to up-regulate ALOX5, down-regulate CYP1A2, and play a role in promoting testicular activity by participating in the steroid hormone biosynthesis pathway. In summary, our study not only provides new insights into the biochemical mechanisms of natural compounds in the treatment of TDF, but also provides a research strategy that integrates cell metabolomics and network pharmacology in order to promote the screening of new drugs for the treatment of TDF.
Background
Fibrotic tumor stroma (FTS) has been implicated in cancer promotion in several neoplasms. The histological features of FTS are convenient and easily accessible in clinical routine in ...intrahepatic cholangiocarcinoma (ICC) specimens. The goal of this study was to explore prognostic impacts of the quantity and maturity of FTS on surgical ICC patients. Moreover, we aimed to propose an efficient prognostic nomogram for postoperative ICC patients.
Materials and Methods
The clinical profiles of 154 consecutive postoperative ICC patients were retrospectively analyzed. Tumor‐stroma ratio and morphological maturity of FTS were evaluated on hematoxylin and eosin‐stained tumor sections. CD3, CD8, and α‐smooth muscle actin (α‐SMA) staining were performed on corresponding tissue microarrays. The nomogram was established on variables selected by multivariate analyses and was validated in 10‐fold cross‐validation.
Results
Rich tumor stroma and strong α‐SMA expression were associated with poor overall survival (OS). However, in multivariate analyses, these two biomarkers failed to stratify both OS and recurrence‐free survival (RFS). Immature FTS was correlated with tumor multiplicity, advanced clinical stage, and sparser CD3 and CD8 positive tumor‐infiltrating lymphocytes (TILs) and was identified as an independent prognostic indicator for both OS and RFS. The nomogram comprising FTS maturity, tumor number, microvascular invasion, and lymph node metastasis possessed higher predictive power relative to conventional staging systems.
Conclusion
Immature FTS was an independent risk factor for survival and was associated with sparser CD3 and CD8 positive TILs in ICC. The prognostic nomogram integrating the maturity of FTS offers a more accurate risk stratification for postoperative ICC patients.
Implications for Practice
Accumulating evidence has suggested that fibrotic components in tumor microenvironment (TME) play a complicated and vital role in TME reprogramming and cancer progression. However, in clinical practice, the evaluation of fibrotic tumor stroma (FTS) is still neglected to some extent. This study's findings indicated that, in intrahepatic cholangiocarcinoma (ICC), the histological maturity of FTS is a robust prognostic indicator for patients who underwent curative resection. Moreover, prognostic nomogram constructed on the maturity of FTS possessed higher predictive power relative to the conventional tumor‐node‐metastasis staging systems. Taken together, the evaluation of FTS should be emphasized in clinical routine for more accurate prognostic prediction in postoperative ICC patients.
摘要
背景。纤维化肿瘤间质 (FTS) 被认为与促进某些肿瘤发展密切相关。在肝内胆管癌 (ICC) 样本的临床常规方面,FTS的组织学特征方便易取。本研究的目标是探求 FTS 的数量及成熟度对外科手术 ICC 患者的预后影响。此外,我们计划为术后 ICC 患者提供一份有效的预后列线图。
材料和方法。回顾性分析连续154位术后 ICC 患者的临床特征。在苏木精和伊红染色的肿瘤切片上对肿瘤间质比率和 FTS 的形态学成熟度进行了评估。在相应的组织微阵列上进行了 CD3、CD8 和 α 平滑肌肌动蛋白 (α‐SMA) 染色。列线图通过多元分析选定的变量制定而成,并经过十倍交叉验证。
结果。丰富的肿瘤基质和较强的 α‐SMA 表达与较差的总生存 (OS) 相关。但是,在多元分析中,这两种生物指标未能将 OS 和无复发生存 (RFS) 分层。未成熟的 FTS 与肿瘤多发率、临床晚期及稀少的 CD3 和 CD8 阳性肿瘤浸润性淋巴细胞 (TIL) 相关,并被认定为 OS 和 RFS 的独立预后指标。与传统的分期系统相比,由 FTS 成熟度、肿瘤数量、微血管侵犯和淋巴结转移组成的列线图具有更高的预测能力。
结论。未成熟的 FTS 是影响生存率的独立危险因素,且与 ICC 中稀少的 CD3 和 CD8 阳性 TIL 相关。整合 FTS 成熟度的预后列线图会为术后 ICC 患者提供更为准确的危险分层
This article evaluates the prognostic significance of tumor‐stroma and the maturity of fibrotic tumor stroma and α‐smooth muscle actin expression in a larger cohort of intrahepatic cholangiocarcinoma. A prognostic nomogram was established based on the findings, and it offers a simple way to predict survival with reference to the histological features of FTS in ICC.
PDF
