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1.
J Ethnopharmacol ; 246: 112207, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31476440

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Liuwei Dihuang (LWDH) is a classic prescription that has been used as a traditional medicinal formula for more than 1000 years in China. In clinical, LWDF is used for treating functional decline associated with senile disease and menopausal syndrome. Studies have demonstrated that LWDH could significantly improve estrogen level and ER expression, and suspend the process of atherosclerosis. However, the under mechanism of how LWDH suppressing VSMCs phenotypic conversion and proliferation through ER is still unknown. AIM OF THE STUDY: This study was to reveal the under mechanism of how LWDH inhibits the phenotypic conversion of VSMCs. MATERIALS AND METHODS: 24 ApoE-/- mice were divided into 4 groups: sham group, model group, E2 group, and LWDH group, and 6 C57BN/L6 mice were used as control group. The primary VSMCs were divided into control group, model group, E2 group, LWDH group, LWDH + MPP group, and LWDH + PHTPP group with or without control siRNA, ERα siRNA, ERß siRNA, and myocardin siRNA. Oil red staining was used to evaluate the lipid deposition in the cardiac aorta. Serum chemistry analysis to test serum TG, TC, LDL, and HDL. Immunofluorescence staining was used to test α-SMA, osteopontin and F-actin. Immunohistochemical staining was performed to check out the myocardin in the cardiac aorta. The mRNA levels of α-SMA, osteopontin, ERα, ERß, SRC3 and myocardin were detected by Real Time-PCR, and the protein expression levels of them were detected by Western blotting. Co-immunoprecipitation was proceed to test the interaction between ERα and SRC3 and SRC3 and myocardin. Flow cytometry was used to check out the cell cycle. Wound healing assay and Transwell were managed to evaluate the migration capacity of VSMCs. RESULTS: In vivo administration of LWDH suppressed AS symptoms, decreases phenotypic marker of vascular endothelial cell, and increases phenotypic marker of VSMC in ovariectomized ApoE-/- female mice. Moreover, LWDH significantly increased the mRNA and protein expression levels of ERα, ERß, SRC3 and myocardin in the cardiac aorta of ovariectomized ApoE-/- female mice. In vitro, LWDH altered cell cycle and reduced the elevated cyclinD protein expression migration capacity and in the model VSMCs. In addition, LWDH inhibited phenotypic conversion and promoted the expression of ER, SRC3, and myocardin of the primary VSMC phenotypic conversion model. Inhibition of ERα almost completely eliminated the impacts of LWDH on α- SMA and osteopontin. Furthermore, LWDH promoted the interaction between ERα and SRC3 and up-regulated the co-activation of SRC3 and myocardin. CONCLUSIONS: LWDH could inhibit the phenotypic conversion of VSMCs in vitro and in vivo by increasing the activity of myocardin through up-regulating the expression of ERα and promoting the interaction between ERα and SRC3. Our research reveals the under mechanism of how LWDH inhibits the phenotypic conversion of VSMCs.

2.
Cancer Med ; 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31599129

RESUMO

BACKGROUND: Inflammatory factors have been considered a significant factor contributing to the development and progression of glioma. However, the relationship between circulating inflammatory factors and glioma risk as well as their prognostic values in glioma patients is still inconclusive. Here, we performed a meta-analysis to address this issue. METHODS: Relevant articles were identified through PubMed, EMBASE, the Cochrane Library, Web of Science, Wanfang database, and China National Knowledge Infrastructure (CNKI) from inception to February 2019. The weighted mean differences (WMDs) or standard mean differences (SMDs) with 95% confidence intervals (CIs) were used to describe the predictive ability of the levels of circulating inflammatory factors on glioma risk. To evaluate the prognostic values of the circulating inflammatory factors in glioma, hazard ratios (HRs) with 95% CIs were used. RESULTS: Thirty-one studies comprising 2587 patients were included. The overall analysis showed that increased circulating interleukin-6 (IL-6) [SMD 0.81 (95% CI: 0.21-1.40; P = .008)], interleukin-8 (IL-8) [SMD 1.01 (95% CI: 0.17-1.84; P = .018)], interleukin-17 (IL-17) [SMD 1.12 (95% CI: 0.26-1.98; P = .011)], tumor necrosis factor-α (TNF-α) [SMD 1.80 (95% CI: 1.03-2.56; P = .000)], transforming growth factor-ß (TGF-ß) [SMD 10.55 (95% CI: 5.59-15.51; P = .000)], and C-reactive protein (CRP) [SMD 0.95 (95% CI: 0.75-1.15; P = .000)] levels were significantly associated with glioma risk. On the other hand, our results showed that circulating IL-6 [HR 1.10 (95% CI: 1.05-1.16; P = .000)] and CRP [HR 2.02 (95% CI: 1.52-2.68; P = .000)] levels were highly correlated with a poor overall survival (OS) rate in glioma patients. CONCLUSION: Our results indicate that increased circulating IL-6, IL-8, IL-17, TNF-α, TGF-ß, and CRP levels are significantly associated with increased glioma risk. Moreover, our meta-analysis suggests that circulating IL-6 and CRP may serve as powerful biomarkers for a poor prognosis in glioma patients.

3.
Artigo em Inglês | MEDLINE | ID: mdl-31614055

RESUMO

Preparation of large single crystals for linear polymers that are amenable to X-ray analysis is very challenging in polymer science. Herein, we employed a coordination driven self-assembly strategy to secure appropriate head-to-tail alignment of anthracene moieties, and for the first time obtained large-sized Pt-based linear polymer crystals through a [4+4] cycloaddition of anthracene in a single-crystal to single-crystal fashion. Using X-ray diffraction analysis to precisely determine polymer crystal structure, we revealed that both the polymerisation and depolymerisation steps proceed via a stable intermediate. Taking advantage of the temperature-dependent slow depolymerization, the afforded Pt-based linear polymer showed potential as a sustained release anticancer drug platform. Furthermore, utilizing the reversible contraction effect of unit-cell volume upon irradiation or heating, the stimuli-responsive crystals were hybridized with polyvinylidene fluoride to obtain a'smart material' with outstanding photoactuator performance. This work not only provides a new approach to prepare metal-containing linear polymer crystals, but also broadens their potential applications towards drug controlled-release and actuator functions.

4.
Artigo em Inglês | MEDLINE | ID: mdl-31660782

RESUMO

Objectives: To study the epidemiological characteristics of malaria and the effects of comprehensive malaria control implementation in Yantai, as well as to provide a scientific basis for future malaria elimination. Materials and Methods: A retrospective analysis was conducted to explore the epidemiological changes and prevention effects in Yantai from 1951 to 2017. The malaria data before 2004 were collected from paper-based annual reports, and data after 2004 came from the Infectious Diseases Information Reporting Management System. Results: A total of 81,286 malaria cases were identified in Yantai from 1957 to 2017, with two peaks occurring in 1966 (120.93/100,000) and 1970-1972 (366.12/100,000). From 1951 to 2003, the case classification was mainly Plasmodium vivax (99.80%); the first case attributed to Plasmodium falciparum occurred in 2004, and P. falciparum became the main cause of malaria after 2011. All cases reported since 2010 have been imported cases, and the last indigenous case was caused by P. vivax in 2008. A total of 129 imported cases were reported from 2010 to 2017, most of which originated in Africa (93.80%), mainly in men aged 30-49 years (68.28%). From 1951 to 1973, 73,868 cases of malaria were diagnosed with clinical symptoms, and from 1974 to 2017, 818,943 cases in fever patients were diagnosed with blood tests. Conclusions: To achieve the goal of eliminating malaria by 2020, Yantai should continue to strengthen the management of migrant population, including improving malaria surveillance for returnees and immigrants from overseas endemic areas, and continue to increase the training of medical personnel to improve their diagnostic ability.

5.
Aging (Albany NY) ; 11(19): 8664-8680, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31606726

RESUMO

Osteoarthritis (OA) is the most common degenerative joint disease and involves the loss of articular cartilage integrity, formation of articular osteophytes, remodeling of subchondral bone, and synovitis. Knockdown of receptor interacting serine/threonine kinase (RIPK) 1 leads to anti-inflammatory and anti-apoptotic effects. However, the involvement of RIPK1 in the pathogenesis of OA is unclear. Here, we evaluated the effect of RIPK1 on chondrocytes and elaborated the underlying molecular mechanism. Knockdown of RIPK1 protected chondrocytes against inflammation and apoptosis induced by interleukin (IL)-1ß in vitro and in vivo. RIPK1 was required for myeloid differentiation primary response 88 (MyD88)- and TIR-domain-containing adapter-inducing interferon b (TRIF)-mediated production of matrix metalloproteinases (MMPs) in OA. Moreover, overexpression of RIPK1 promoted the expression of tumor necrosis factor receptor-associated factor 2 (TRAF2), which blocked the expression and phosphorylation of RIPK1. Upregulation of TRAF2 decreased the expression of TRIF, MyD88, and MMPs in chondrocytes. Furthermore, knockdown of RIPK1 blocked activation of the nuclear factor-κB (NF-κB) and c-Jun N-terminal kinase (JNK) signaling pathways. In summary, knockdown of RIPK1 alleviated OA in a manner mediated by the TRIF/MyD88-RIPK1-TRAF2 negative feedback loop and activation of the NF-κB and JNK signaling pathways.

6.
J Ethnopharmacol ; : 112326, 2019 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-31639486

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Mulberry (Morus alba L.) leaves have been widely applied to controlling blood glucose as an efficacious traditional Chinese medicine or salutary medical supplement. The extracts of mulberry leaf suppress inflammatory mediators and oxidative stress, protect the pancreatic ß-cells and modulate glucose metabolism in diabetic rats. Our previous studies and others have shown that mulberry leaf extract has excellent therapeutic effects on type 2 diabetes mellitus (T2DM), however, the underlying mechanism remains to be studied. AIM OF THE STUDY: Skeletal muscle insulin resistance (IR) plays an important role in the pathogenesis of T2DM. The aim of this study was to investigate the effects and mechanisms of Mulberry leaf flavonoids (MLF) in L6 skeletal muscle cells and db/db mice. MATERIALS AND METHODS: L6 skeletal muscle cells were cultured and treated with/without MLF for in vitro studies. For in vivo studies, the db/db mice with/without MLF therapy were used. RESULTS: MLF and metformin significantly ameliorated muscle glucose uptake and mitochondrial function in L6 muscle cells. MLF also increased the phosphorylation of AMPK and the expression of PGC-1α, and upregulated the protein levels of m-GLUT4 and T-GLUT4. These effects were reversed by the AMPK inhibitor compound C. In db/db mice, MLF improve diabetes symptoms and insulin resistance. Moreover, MLF elevated the levels of p-AMPK and PGC-1α, raised m-GLUT4 and T-GLUT4 protein expression, and ameliorated mitochondrial function in skeletal muscle of db/db mice. CONCLUSIONS: MLF significantly improved skeletal muscle insulin resistance and mitochondrial function in db/db mice and L6 myocytes through AMPK-PGC-1α signaling pathway, and our findings support the therapeutic effects of MLF on type 2 diabetes.

7.
Top Curr Chem (Cham) ; 377(6): 34, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31664532

RESUMO

Given the unique properties of metal-organic frameworks (MOFs) including adjustable porosity, high surface area, and easy modification, they have attracted great attention as excellent solid supports for the incorporation of biomolecules. The formed biomolecules-MOFs composites show promising prospects in various fields such as biocatalysis, drug delivery, and biosensing. This review focuses on the state-of-the-art of biomolecules-incorporation using MOFs. Moreover, the relationship between properties of MOFs and biomolecules-incorporation is also discussed and highlighted. We hope this work will inspire the innovation in this emerging field for highly efficient synthesis of biomolecules-MOFs composites with various properties and advanced applications.

8.
Artigo em Inglês | MEDLINE | ID: mdl-31647866

RESUMO

A development of methodology for designing superior sorbents of oxoanions is performed. To integrate high efficiency of chemi-sorption, selectivity and recyclability into one sorbent, understanding the nature of oxoanions-sorbent interactions and the struc-tural evolution of the sorbents is essential. Three cationic Ag(I) coordination polymers (CPs) are synthesized for dichromate (Cr2O72-) removal and three distinct oxoanion-exchange mechanisms are identified, namely the replacement, breath, and recon-struction processes, depending on degree of the framework distortion induced by the dichromate-CP interactions. The single-crystal to single-crystal transformation during the oxoanion-exchange has been investigated by using single-crystal X-ray diffrac-tion, energy dispersive X-ray microanalysis. The replacement process due to a weak chemisorption shows excellent recyclability in cost of reduction of efficiency and selectivity of adsorption. The reconstruction process may achieve a high efficiency and selec-tivity, but it loses recyclability. Due to the formation of Ag-O(dichromate) bond and breathing effect of the framework, the sorbent with the breath mechanism shows both superior efficiency and high recyclability in dichromate removal. Study of per-rhenate (ReO4-) removal using the same CPs demonstrates that one CP performing the reconstruction process in dichromate re-moval turns to the breath process in removal of perrhenate anions. These results of mechanism-property correlation provide an in-sight into improvement of the methodology to fabricate the most superior CP sorbent for oxoanion removal.

9.
Aging (Albany NY) ; 11(17): 6805-6838, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31477638

RESUMO

Long non-coding RNAs play critical roles in tumorigenesis and the immune process. In this study, RNA sequencing data for 946 glioma samples from The Cancer Genome Atlas and the Chinese Glioma Genome Atlas databases were analyzed to evaluate the prognostic value and function of homeobox A transcript antisense RNA myeloid-specific (HOTAIRM)1. HOTAIRM1 expression was associated with clinical and molecular features of glioma: patients with high HOTAIRM1 expression were more likely to be classified as malignant cases, and elevated HOTAIRM1 level was associated with shorter survival time in subgroups stratified by clinical and molecular features. A multivariate Cox regression analysis showed that HOTAIRM1 was an independent prognostic factor for patient outcome. In vitro experiments revealed that HOTAIRM1 knockdown suppressed the malignant behavior of glioma and increased tumor sensitivity to temozolomide. The results of an in silico analysis indicated that HOTAIRM1 promotes the malignancy of glioma by acting as a sponge for microRNA (miR)-129-5p and miR-495-3p. HOTAIRM1 overexpression was also associated with immune activation characterized by enhanced T cell-mediated immune and inflammatory responses. These results suggest that HOTAIRM1 is a prognostic biomarker and potential therapeutic target in glioma.

10.
Ying Yong Sheng Tai Xue Bao ; 30(9): 2949-2954, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31529869

RESUMO

Monthly phytolith-occluded organic carbon (PhytOC) content in living leaves and litterfall of Moso bamboo (Phyllostachys edulis) were measured for a year. The PhytOC sequestration rate in living leaves of different months were compared with that in annual litterfall to determine the optimum sampling time of living leaves for estimating PhytOC sequestration rate of Moso bamboo. The contents of phytoliths and PhytOC in living leaves of Moso bamboos were 23.45-101.07 g·kg-1 and 0.73-1.98 g·kg-1, respectively, with significant difference among different months. The monthly PhytOC sequestration rates of living leaves of Moso bamboo in different months ranged from 0.75 to 7.68 kg·hm-2·a-1. The maximum and minimum rates of the PhytOC sequestration occurred in December and April respectively, with significant difference between them. There was no difference between the PhytOC sequestration rate in living leaves of Moso bamboos in February or December and that of litterfall in the whole year. Therefore, February or December should be the optimal month of sampling living leaves for estimating the PhytOC sequestration rate of Moso bamboo stands.


Assuntos
Sequestro de Carbono , Poaceae/fisiologia , Carbono , Folhas de Planta/fisiologia
11.
Eur J Med Chem ; 182: 111652, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31494470

RESUMO

Farnesoid X receptor (FXR) is a key regulator in charge of bile acid synthesis, transport, and metabolism. Activation of FXR represses bile acid synthesis and increases its excretion and transport, consequently protecting the liver functions. Thus, FXR is considered as a critical therapeutic target of cholestasis and nonalcoholic steatohepatitis. Herein, we isolated and identified fourteen new protostane-type triterpenoids (1-14) and four known analogues (15-18) from Alisma orientale, and finally constructed a small library of protostane-type triterpenoids (1-70) to investigate their structure-activity relationship with FXR, further leading to obtain compound 15 with potent agonistic activity against FXR (EC50 = 90 nM). Extensive in vitro investigation confirmed high efficacy of compound 15 against FXR in living cell, and revealed its underlying mechanism for FXR activation (amino acid residues Arg331 and Ser332) by molecular docking and site-directed mutagenesis technology.

12.
Mol Ther Nucleic Acids ; 18: 155-165, 2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31546150

RESUMO

Menin displays either tumor suppression or promotion functions in a context-dependent manner. Previously, we proposed that Menin acts as a tumor suppressor by inhibiting cell growth in pancreatic ductal adenocarcinoma (PDAC), whereas the relationship between the Menin expression and overall survival rate of PDAC patients has not been completely elucidated, indicating the complexity of Menin functions in PDAC progression. Here, we identify Menin as a promoter of epithelial-mesenchymal transition (EMT), which is largely associated with cell migration or metastasis, with modest activity in cell growth inhibition. Ectopic expression of Menin suppresses the expression of CCAAT/enhancer-binding protein beta (CEBPB) and epithelial-specific genes by histone deacetylation and further enhances the TGF-ß signaling-related EMT process. We also demonstrate that CCAAT/enhancer binding protein (C/EBP) beta (C/EBPß; encoded by CEBPB) acts downstream of Menin and TGF-ß signaling for balancing growth inhibition and EMT, and C/EBPß overexpression could restore the anti-cancer functions of Menin in pancreatic cancer by cooperatively activating CDKN2A/B genes and antagonizing EMT processes. Taken together, our results suggest that Menin functions as an oncogene for cancer metastasis upon C/EBPß depletion or acts as a tumor suppressor by cooperation with C/EBPß to activate CDKN2A transcription.

13.
Chemosphere ; 235: 1073-1080, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31561297

RESUMO

As one of emerging contaminants, microplastics (MPs) can enter the environment and adsorb toxic metals such as cadmium (Cd), thereby causing potential environmental risks. However, adsorption characteristics of MPs are poorly understood. Herein, batch experiments were performed to investigate the adsorption characteristics of Cd onto high-density polyethylene (HDPE) MPs with different particle sizes, that is, 1-2 mm, 0.6-1 mm, and 100-154 µm. The adsorption of Cd was quite rapid initially, and the equilibrium time was approximately 90 min. An increase in the pH of the Cd solution led to an increase in Cd adsorption. MPs with particle size of 100-154 µm had the highest adsorption capacity. Addition of 1, 10, and 100 mg/L NaCl all significantly decreased Cd adsorption. Adsorption kinetics fitted the pseudo-second-order model. Adsorption isotherm followed the Langmuir model and, to a lesser extent, the Freundlich model, with estimated maximum adsorption capacity of 30.5 µg/g. The adsorbed Cd easily desorbed from the MPs. Energy-dispersive X-ray spectroscopy (EDS) analysis confirmed Cd adsorption to and desorption from MPs. Fourier transform infrared (FTIR) spectroscopy analysis showed no new functional groups formed during the adsorption and desorption processes, suggesting physical interaction may dominate the Cd adsorption onto MPs. The present study findings provide evidence that MPs can accumulate Cd, and the adsorbed Cd may be highly available, thus posing risks to the organisms exposed to these MPs.


Assuntos
Cádmio/química , Plásticos/química , Água/química , Adsorção , Cinética , Tamanho da Partícula , Polietileno/química , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier
14.
J Knee Surg ; 2019 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-31394588

RESUMO

Blood loss after total knee arthroplasty (TKA) is a potentially serious medical problem since it leads to anemia, increased need for transfusion, and prolonged hospitalization. Some studies have reported that sealing of the intramedullary femoral canal during TKA may decrease postoperative blood loss. The purpose of this study is to determine the effects of sealing of the intramedullary femoral canal during TKA on blood loss and transfusion rate. Electronic databases, PubMed, EMBASE, the Cochrane Library, Web of Science, and Chinese Biomedical Database, were systematically searched. Only randomized controlled trials (RCTs) that compared the sealing group with the control group during TKA were included up to March 2019. Two reviewers independently extracted data and assessed the quality of included studies. The statistical analysis was performed by using Review Manager 5.3 software. Cochrane Risk of Bias tool was used for quality assessment. Overall, eight RCTs involving 996 patients met our criteria and were analyzed. The results of meta-analysis showed that patients in the sealed group had less total blood loss, less total drain output and less hidden blood loss, less transfusion rates, a lower drop of hemoglobin level at day 1 postoperatively, and less hematoma than the control group. On the other hand, there were no significant differences in infection, deep vein thrombosis, and redness of incision between sealed and control group. Current meta-analysis found that sealing the femoral canal during TKA was an effective method for the control of blood loss.

15.
Nanoscale ; 11(33): 15605-15611, 2019 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-31403639

RESUMO

Two-dimensional boron (borophene) features structural polymorphs and distinct in-plane anisotropy, opening opportunities to achieve tailored electronic properties by intermixing different phases. Here, using scanning tunneling spectroscopy combined with first-principles calculations, delocalized one-dimensional nearly free electron states (NFE) in the (2,3) or ß12 borophene sheet on the Ag(111) surface were observed. The NFE states emerge from a line defect in borophene, manifested as a structural unit of the (2,2) or χ3 sheet, which creates an in-plane potential well that shifts the states toward the Fermi level. The NFE states are held near the 2D plane of borophene, rather than in the vacuum region as observed in other nanostructures. Furthermore, borophene can provide a rare prototype to further study novel NFE behaviors, which may have potential applications in transport or field emission nanodevices based on boron.

16.
Angew Chem Int Ed Engl ; 58(43): 15362-15366, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31441563

RESUMO

The electrochemical nitrogen reduction reaction (NRR) offers an energy-saving and environmentally friendly approach to produce ammonia under ambient conditions. However, traditional catalysts have extremely poor NRR performances because of their low activity and the competitive hydrogen evolution reaction. The high catalytic activity of nanoporous gold (NPG) and the hydrophobicity and molecular concentrating effect of the zeolitic imidazolate framework-8 (ZIF-8) were incorporated in the NPG@ZIF-8 nanocomposite so that the ZIF-8 shell could weaken hydrogen evolution and retard reactant diffusion. A highest Faradaic efficiency of 44 % and an excellent rate of ammonia production of (28.7±0.9) µg h-1 cm-2 were achieved, which are superior to traditional gold nanoparticles and NPG. Moreover, the composite catalyst shows high electrochemical stability and selectivity (98 %). The superior NRR performance makes NPG@ZIF-8 one of the most promising water-based NRR electrocatalysts for ammonia production.

17.
Chem Commun (Camb) ; 55(74): 11000-11012, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31455967

RESUMO

Single-chain magnets (SCMs) are one-dimensional (1D) coordination polymers that exhibit magnetic bistability and have potential application in high-density information processing. Usually SCMs are magnetically isolated chains stacked by hydrogen bonds or ππ stacking; however, with the rapid development of metal-organic frameworks (MOFs), coordination chains assembled in MOFs have also shown SCM behaviour when the 1D magnetic correlation is strong enough in comparison to the other two dimensionalities. The high-dimensional framework of MOFs could also help in the formation of coordination chains that cannot form in isolated one-dimensional coordination systems. This feature article highlights the progress in this field by summarizing cobalt(ii)-based MOFs exhibiting SCM behaviour and classifying them into categories according to the bridging ligands within the CoII chains, to provide fundamentals for further studies on the magnetic properties of coordination chains assembled in MOFs.

18.
Artigo em Inglês | MEDLINE | ID: mdl-31400186

RESUMO

Stable metal clusters that can resist both highly concentrated acid and alkali are unknown. Herein, we present a discrete neutral cluster, Hf13 (µ4 -O)8 (OCH3 )36 (1), which features extraordinary chemical stability by preserving its crystalline state in concentrated aqueous solutions of both acid (10 m HNO3 ) and alkali (20 m boiling NaOH). Importantly, 1 can serve as a luminescent probe for detecting both concentrated alkali (20 m NaOH) and strong acid (1 m HNO3 ) with high selectivity and repeatability. DFT studies of the electronic structure and bonding revealed that 1 has an extremely large HOMO-LUMO gap due to strong d π-p π bonding that accounts for the ultrahigh stability.

19.
Eur Radiol ; 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31372786

RESUMO

OBJECTIVES: To explore the utility of dynamic contrast-enhanced MRI (DCE-MRI) and readout-segmented diffusion-weighted imaging (RESOLVE-DWI) in the differentiation of nasopharyngeal carcinoma (NPC) and nasopharyngeal lymphoma (NPL). METHODS: Sixty-two patients with NPC and 39 patients with NPL who underwent DCE-MRI and RESOLVE-DWI examinations were evaluated. The time signal-intensity curve (TIC) types, time to peak (TTP), enhancement peak (EP), maximum contrast enhancement ratio (MCER), washout ratio (WR), apparent diffusion coefficient (ADC), and relative ADC (rADC) values were calculated. Statistical analysis between the two groups was performed to determine the statistical significance of each parameter. Receiver operating characteristic (ROC) curve analysis and binary logistic regression analysis were used to assess the diagnostic ability of single and combined metrics for distinguishing NPC from NPL. RESULTS: The most common TIC curve was type III in patients with NPC (n = 26), while the majority of the curves were types I (n = 14) and II (n = 19) in patients with NPL. TTP, EP, MCER, ADC, and rADC were statistically significantly different between NPCs and NPLs (p < 0.05). Among these factors, ADC revealed the most reliable diagnostic performance, followed by rADC, TTP, MCER, and EP. Moreover, the diagnostic efficiency of the combined DCE-MRI parameters was higher than that of TTP, MCER, and EP each alone. In addition, the combination of all DCE-MRI and DWI parameters together demonstrated the highest diagnostic efficiency (area under the curve = 0.961). However, none of the parameters was significantly different between keratinising NPC and non-keratinising NPC or between NK/T lymphoma and diffuse large B cell lymphoma (all p > 0.05). CONCLUSION: DCE-MRI and RESOLVE-DWI are effective in differentiating NPC from NPL. KEY POINTS: • RESOLVE offers high image quality in the head and neck regions. • Dynamic contrast-enhanced MRI and RESOLVE-DWI help clinicians to make the differential diagnosis between NPC and NPL. • The combination of all the DCE-MRI and DWI parameters together demonstrated the highest diagnostic efficiency compared with each parameter alone.

20.
Bioresour Technol ; 289: 121762, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31311731

RESUMO

In this work, glucose addition (0.7 g l-1) almost doubled hydrogen yield of Chlorella pyrenoidosa (121.1 ml l-1 vs 65.5 ml l-1), with a positive correlation between hydrogen production and glucose consumption (-0.977, P < 0.01). When the electrons transport from water photolysis to algal hydrogenase was inhibited, the hydrogen productivity declined by 21.1%; whereas it dramatically decreased by 70.9% when the algal nicotinamide adeninedinucleotide dehydrogenase (NADH) was inhibited. Therefore, in the presence of glucose, the electrons for algae based hydrogen production would be mainly from glucose glycolysis rather than water photolysis. Further deuterated-glucose trial indicated that the glucose might serve as an electron donor for algal hydrogenases. Finally, a tentative electron transport route from glucose to algal hydrogenase was proposed, hoping to provide more scientific direction for further algae-based hydrogen production improvement.


Assuntos
Chlorella/metabolismo , Hidrogênio/metabolismo , Hidrogenase/metabolismo , Transporte de Elétrons , Elétrons , Glucose/metabolismo , Fotólise
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