Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 95
Filtrar
1.
Small ; : e2402105, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38727184

RESUMO

The scarcity of fresh water necessitates sustainable and efficient water desalination strategies. Solar-driven steam generation (SSG), which employs solar energy for water evaporation, has emerged as a promising approach. Graphene oxide (GO)-based membranes possess advantages like capillary action and Marangoni effect, but their stacking defects and dead zones of flexible flakes hinders efficient water transportation, thus the evaporation rate lag behind unobstructed-porous 3D evaporators. Therefore, fundamental mass-transfer approach for optimizing SSG evaporators offers new horizons. Herein, a universal multi-force-fields-based method is presented to regularize membrane channels, which can mechanically eliminate inherent interlayer stackings and defects. Both characterization and simulation demonstrate the effectiveness of this approach across different scales and explain the intrinsic mechanism of mass-transfer enhancement. When combined with a structurally optimized substrate, the 4Laponite@GO-1 achieves evaporation rate of 2.782 kg m-2 h-1 with 94.48% evaporation efficiency, which is comparable with most 3D evaporators. Moreover, the optimized membrane exhibits excellent cycling stability (10 days) and tolerance to extreme conditions (pH 1-14, salinity 1%-15%), verifies the robust structural stability of regularized channels. This optimization strategy provides simple but efficient way to enhance the SSG performance of GO-based membranes, facilitating their extensive application in sustainable water purification technologies.

2.
Angew Chem Int Ed Engl ; 63(24): e202400549, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38595043

RESUMO

The stability of platinum-based alloy catalysts is crucial for the future development of proton exchange membrane fuel cells, considering the potential dissolution of transition metals under complex operating conditions. Here, we report on a Rh-doped Pt3Co alloy that exhibits strong interatomic interactions, thereby enhancing the durability of fuel cells. The Rh-Pt3Co/C catalyst demonstrates exceptional catalytic activity for oxygen reduction reactions (ORR) (1.31 A mgPt -1 at 0.9 V vs. the reversible hydrogen electrode (RHE) and maintaining 92 % of its mass activity after 170,000 potential cycles). Long-term testing has shown direct inhibition of Co dissolution in Rh-Pt3Co/C. Furthermore, tests on proton exchange membrane fuel cells (PEMFC) have shown excellent performance and long-term durability with low Pt loading. After 50,000 cycles, there was no voltage loss at 0.8 A cm-2 for Rh-Pt3Co/C, while Pt3Co/C experienced a loss of 200 mV. Theoretical calculations suggest that introducing transition metal atoms through doping creates a stronger compressive strain, which in turn leads to increased catalytic activity. Additionally, Rh doping increases the energy barrier for Co diffusion in the bulk phase, while also raising the vacancy formation energy of the surface Pt. This ensures the long-term stability of the alloy over the course of the cycle.

3.
Angew Chem Int Ed Engl ; : e202408414, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38850273

RESUMO

Transition metal oxides (TMOs) are promising cathode materials for aqueous zinc ion batteries (ZIBs), however, their performance is hindered by a substantial Hubbard gap, which limits electron transfer and battery cyclability. Addressing this, we introduce a heteroatom coordination approach, using triethanolamine to induce axial N coordination on Mn centers in MnO2, yielding N-coordinated MnO2 (TEAMO). This approach leverages the change of electronegativity disparity between Mn and ligands (O and N) to disrupt spin symmetry and augment spin polarization. This enhancement leads to the closure of the Hubbard gap, primarily driven by the intensified occupancy of the Mn eg orbitals. The resultant TEAMO exhibit a significant increase in storage capacity, reaching 351 mAh g-1 at 0.1 A g-1. Our findings suggest a viable strategy for optimizing the electronic structure of TMO cathodes, enhancing the potential of ZIBs in energy storage technology.

4.
Small ; 19(52): e2305308, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37635096

RESUMO

The evolution and formation process of two-dimensional metal-organic frameworks (MOFs) primarily arise from the anisotropic growth of crystals, leading to variations in photocatalytic performance. It is crucial to achieve a synergistic combination of anisotropic electron transfer direction and dimension reduction strategies. In this study, a novel approach that effectively blocks crystal growth accretion through the coordination of solvent molecules is presented, achieving the successful synthesis of impurity-free two-dimensional nanosheet Zn-PTC with exceptional hydrogen evolution reaction (HER) performance (15.4 mmol g-1  h-1 ). The structural and photophysical characterizations validate the successful prevention of crystal accretion, while establishing correlation between structural anisotropy and intrinsic charge transfer mode through transient spectroscopy. These findings unequivocally demonstrate that electron transfer along the [001] direction plays a pivotal role in the redox performance of nano-Zn-PTC. Subsequently, by coupling the photocatalytic performance and density functional theory (DFT) simulation calculations, the carrier diffusion kinetics is explored, revealing that effective dimension reduction along the ligand-to-metal charge transfer (LMCT) direction is the key to achieving superior photocatalytic performance.

5.
Small ; 19(25): e2207671, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36734204

RESUMO

The vigorous development of efficient platinum group metal-free catalysts is considerably important to facilitate the universal application of proton exchange membrane fuel cells. Although nitrogen-coordinated atomic iron intercalated in carbon matrix (Fe-N-C) catalysts exhibit promising catalytic activity, the performance in fuel cells, especially the short lifetime, remains an obstacle. Herein, a highly-active Fe-N-C catalyst with a power density of >1 w cm-2 and prolonged discharge stability with a current density of 357 mA cm-2 after 40 h of constant voltage discharge at 0.7 V in H2 -O2 fuel cells using a controllable and efficient N-C coating strategy is developed. It is clarified that a thicker N-C coating may be more favorable to enhance the stability of Fe-N-C catalysts at the expense of their catalytic activity. The stability enhancement mechanism of the N-C coating strategy is proven to be the synergistic effect of reduced carbon corrosion and iron loss. It is believed that these findings can contribute to the development of Fe-N-C catalysts with high activity and long lifetimes.

6.
Fish Shellfish Immunol ; 141: 109090, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37722443

RESUMO

The detailed crosstalk between the neuroendocrine and immune systems in Oreochromis niloticus, an economically important fish, in response to pathogenic infections, remains unclear. This study revealed the head kidney transcriptional profiles of O. niloticus upon infections with Streptococcus agalactiae, a prevalent pathogen known to cause severe meningitis. Twelve cDNA libraries of O. niloticus head kidney, representing four treatment time points (0, 6, 24, and 48 h), were constructed and a total of 2,528 differentially expressed genes were identified based on pairwise comparisons. KEGG pathway analysis revealed a significant enrichment of the 'neuroactive ligand-receptor interaction' pathway (ko04080), with 13 genes exhibiting differential expression during S. agalactiae infection. Among these, six neuroactive receptor genes (lepr, nr3c1, ptger4, thrb, tspo, and ß2-ar) were selected, cloned, and characterized. Although these genes are ubiquitously expressed, and in head kidney leukocytes, their expression was mainly observed in T cells, Mo/Mφ, and NCCs, which are characterized by antimicrobial responses. Furthermore, we examined the response patterns of these six neuroactive receptor genes to gram-positive (S. agalactiae) and gram-negative (Aeromonas hydrophila) bacteria in four different tissues. Notably, lepr, ptger4, tspo, and ß2-ar were upregulated in all selected tissues in response to S. agalactiae and A. hydrophila infections. However, nr3c1 and thrb were downregulated in response to S. agalactiae infection in the head kidney and spleen, whereas nr3c1 was upregulated, and thrb was unresponsive to A. hydrophila infection. Our findings provide a theoretical foundation for understanding new links between the neuroendocrine and immune systems during bacterial infection in teleost fish.


Assuntos
Ciclídeos , Infecções Estreptocócicas , Tilápia , Animais , Ciclídeos/genética , Streptococcus agalactiae , Infecções Estreptocócicas/veterinária , Perfilação da Expressão Gênica/veterinária
7.
Int Orthop ; 47(3): 719-734, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36642768

RESUMO

PURPOSE: The reason for graft failure after anterior cruciate ligament reconstruction (ACLR) is multifactorial. Controversies remain regarding the predominant factor and incidence of failure aetiology in the literature. This review aimed to provide a meta-analysis of the literature to evaluate the relative proportion of various failure modes among patients with ACLR failure. METHODS: The PubMed, Embase, Cochrane Library, Web of Science, and EBSCO databases were searched for literature on ACLR failure or revision from 1975 to 2021. Data related to causes for ACLR surgical failure were extracted, and a random effects model was used to pool the results, which incorporates potential heterogeneity. Failure modes were compared between different populations, research methods, graft types, femoral portal techniques, and fixation methods by subgroup analysis or linear regression. Funnel plots were used to identify publication bias and small-study effects. RESULTS: A total of 39 studies were analyzed, including 33 cohort studies and six registry-based studies reporting 6578 failures. The results showed that among patients with ACLR failure or revision, traumatic reinjury was the most common failure mode with a rate of 40% (95% CI: 35-44%), followed by technical error (34%, 95% CI: 28-42%) and biological failure (11%, 95% CI: 7-15%). Femoral tunnel malposition was the most common cause of the technical error (29%, 95% CI: 18-41%), with more than two times higher occurrence than tibial tunnel malposition (11%, 95% CI: 6-16%). Traumatic reinjury was the most common factor for ACLR failure in European populations and in recent studies, while technical errors were more common in Asian populations, earlier studies, and surgery performed using the transtibial (TT) portal technique. Biological factors were more likely to result in ACLR failure in hamstring (HT) autografts compared to bone-patellar tendon-bone (BPTB) autografts. CONCLUSION: Trauma is the most important factor leading to surgical failure or revision following ACLR. Technical error is also an important contributing factor, with femoral tunnel malposition being the leading cause of error resulting in failure.


Assuntos
Lesões do Ligamento Cruzado Anterior , Reconstrução do Ligamento Cruzado Anterior , Ligamento Patelar , Relesões , Humanos , Lesões do Ligamento Cruzado Anterior/complicações , Lesões do Ligamento Cruzado Anterior/epidemiologia , Lesões do Ligamento Cruzado Anterior/cirurgia , Relesões/cirurgia , Reoperação , Reconstrução do Ligamento Cruzado Anterior/efeitos adversos , Reconstrução do Ligamento Cruzado Anterior/métodos , Ligamento Patelar/cirurgia , Autoenxertos/cirurgia , Transplante Autólogo
8.
Small ; 18(4): e2105335, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34841663

RESUMO

Hydrogen produced using renewable electricity is considered the key to achieving a low-carbon energy economy. However, the large-scale application of electrochemical water splitting for hydrogen evolution currently requires expensive platinum-based catalysts. Therefore, it is important to develop efficient and stable catalysts based on the rich reserves of transition metals as alternatives. In this study, the authors prepare a carbon-nanotube material enriched with atomically dispersed CoN sites having uniquely low coordination numbers via the simple mixing, pyrolysis, and leaching of inexpensive precursors. These atomically dispersed low-coordinate CoN sites provide an overpotential of only 82 mV at 10 mA cm-2 for the hydrogen evolution reaction (HER) under challenging acidic conditions and show excellent durability in accelerated stability tests. Theoretical simulations also confirm that these unique, low-coordinate CoN2 sites have lower energy barriers in catalyzing the HER than Fe/NiN2 sites and commonly reported CoN3 /N4 sites. Therefore, the method provides a new concept for the design of single-atom catalytic sites with low coordination numbers. It also serves to reduce the cost of hydrogen production in the future owing to the high catalytic activity, low cost, and scalable production process.

9.
Opt Express ; 30(25): 45553-45568, 2022 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-36522959

RESUMO

The plenoptic function is ideal to describe three-dimensional displays. We propose and demonstrate in this work that plenoptic function is a particularly suitable scenario in the directionally illuminated autostereoscopic display. Guided by this function, backlight structures and functional thin films are designed and applied for wave-vector and amplitude control so that homogeneous viewing is achieved in large viewing volume while display functionality with optical focusing and diverting can be fulfilled. The demonstration of high-quality displays by cloaking various optical defects in an otherwise severely distorted radiance distribution introduced by lens array is presented. We conclude that the scenario adopted in this work is immediately applicable to enhance general performance for autostereoscopy.

10.
J Clin Lab Anal ; 36(9): e24634, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35908776

RESUMO

BACKGROUND: The purpose of this study was to identify biomarkers for the diagnosis of gout in Chinese Han males using methylation microarray profiling. METHODS: We screened for differentially methylated genes (DMGs) in gout using a methylation microarray and analyzed the functions of the DMGs using gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. We verified gene methylation levels by pyrosequencing and protein levels by enzyme-linked immunosorbent assays (ELISAs). Statistical analyses were performed using SPSS. Two-sided p values <0.05 were deemed to be statistically significant for all analyses. RESULTS: We identified 20,426 significant differential methylation sites (5719 high-methylation sites and 14,707 low-methylation sites). Bioinformatics analysis showed that the DMGs were mainly involved in 43 biological functions, 13 cellular components, 18 molecular functions, and 35 KEGG pathways. We selected opioid receptor delta 1 (OPRD1) for verification of methylation levels between 50 gout patients and 50 controls. The methylation levels of OPRD1 (Chr1:29,139,121) were significantly lower in the gout group (p < 0.05), while OPRD1 protein levels were significantly higher in the gout group (p < 0.05). In addition, the AUC of the combination of OPRD1 (Chr1:29,139,121) methylation and OPRD1 protein levels was 0.796 (0.710, 0.883) with a high sensitivity of 82% and a specificity of 68% (p < 0.001). CONCLUSIONS: The combination of OPRD1 (Chr1:29,139,121) hypomethylation and high levels of OPRD1 protein is a potential biomarker for gout diagnosis.


Assuntos
Metilação de DNA , Gota , Receptores Opioides delta/metabolismo , Biologia Computacional , Metilação de DNA/genética , Ontologia Genética , Gota/genética , Humanos , Masculino , Receptores Opioides/genética
11.
Gastroenterol Nurs ; 45(6): 428-439, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35758925

RESUMO

The quality of bowel preparation is an extremely important determinant of colonoscopy results. However, the efficacy of senna regimens in improving bowel cleanliness is uncertain. We conducted a systematic review and meta-analysis to synthesize data on whether using a senna bowel preparation regimen enhances the bowel cleanliness. We searched Web of Science Core Collection, MEDLINE, PubMed, Embase, Cochrane Library, and Scopus databases (from the inception to August 2021). The primary efficacy outcome was bowel cleanliness. Secondary outcomes included patient compliance, tolerance, and adverse events. Eleven trials fulfilled the inclusion criteria (3,343 patients. Overall, we found no significant differences in bowel cleanliness between the senna regimen and other bowel preparation regimens (odds ratio [95% confidence interval]: 1.02 [0.63, 1.67], p = 0.93). There was significant difference in tolerance (odds ratio [95% confidence interval]: 1.66 [1.08, 2.54], p = .02) and compliance (odds ratio [95% confidence interval]: 3.05 [1.42, 6.55], p = .004). The senna regimen yielded a significantly greater proportion of no nausea (odds ratio [95% confidence interval]: 1.84 [1.45, 2.32]) and vomiting (odds ratio [95% confidence interval]: 1.65 [0.81, 3.35]). Compared with other bowel preparation regimens, the senna regimen may be effective and safe in bowel cleaning before colonoscopy, with superior compliance and tolerance.


Assuntos
Catárticos , Colonoscopia , Humanos , Colonoscopia/métodos , Senosídeos , Cooperação do Paciente , Polietilenoglicóis
12.
BMC Infect Dis ; 21(1): 991, 2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34556058

RESUMO

BACKGROUND: The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic. There have been reports that long-term SARS-CoV-2 RNA shedding and re-infection of COVID-19 patients existed. However, the specific mechanism, diagnosis, and treatment of COVID-19 are still unclarified. CASE PRESENTATION: In this case, we reported a 64-year-old patient who had a long-term course of COVID-19 for 174 days with two retests of SARS-CoV-2 RNA positive after discharging from the hospital. The patient's serum immunoglobulin G (IgG) of SARS-CoV-2 tested positive after the initial infection. And during treatment, the CD4 + T cell count and ratio to peripheral blood mononuclear cell (PBMC) were in dynamic change. CONCLUSIONS: Our results suggested that the host immune system responded with IgG production after SARS-CoV-2 infection, but was not protective enough for the patient. The reemergence of SARS-CoV-2 could be related to the cell count and proportion of CD4 + T cells in PBMC. And the increase of CD4 + T cells after treatment may help to clear the virus.


Assuntos
COVID-19 , SARS-CoV-2 , Anticorpos Antivirais , Humanos , Imunidade , Leucócitos Mononucleares , Pessoa de Meia-Idade , Alta do Paciente , RNA Viral/genética
13.
J Am Chem Soc ; 142(5): 2665-2671, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31967811

RESUMO

Surface Action Spectroscopy, a vibrational spectroscopy method developed in recent years at the Fritz Haber Institute is employed for structure determination of clean and H2O-dosed (111) magnetite surfaces. Surface structural information is revealed by using the microscopic surface vibrations as a fingerprint of the surface structure. Such vibrations involve just the topmost atomic layers, and therefore the structural information is truly surface related. Our results strongly support the view that regular Fe3O4(111)/Pt(111) is terminated by the so-called Fetet1 termination, that the biphase termination of Fe3O4(111)/Pt(111) consists of FeO and Fe3O4(111) terminated areas, and we show that the method can differentiate between different water structures in H2O-derived adsorbate layers on Fe3O4(111)/Pt(111). With this, we conclude that the method is a capable new member in the set of techniques providing crucial information to elucidate surface structures. The method does not rely on translational symmetry and can therefore also be applied to systems which are not well ordered. Even an application to rough surfaces is possible.

14.
J Chem Phys ; 152(10): 104702, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32171208

RESUMO

By virtue of density functional theory calculations, this work discusses several carbonate, carboxylate, and bicarbonate species on two thermodynamically relevant metal terminations of the (111) surface of magnetite, Fe3O4. We present adsorption energies and vibrational wavenumbers and conclude in assigning the observed infrared reflection-absorption spectroscopy bands. CO2 prefers to adsorb molecularly on the Fetet1 terminated Fe3O4(111) surface, a finding consistent with observation. Calculations compared with the experiment lead to interpreting results in favor of the Fetet1 (single metal) terminated Fe3O4(111) surface as the regular surface termination. Formation of carbonate and bicarbonate requires metal impurities on that surface. Such impurities exist, for instance, on the Feoct2 (double metal) termination, which can thus be used as a model for "metal-rich terminations" of more complex surfaces.

15.
Pharmacol Res ; 141: 481-500, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30639372

RESUMO

Chinese herbal medicine has been increasingly used for patients with postmenopausal hypertension in China. A comprehensive literature search was performed in 7 electronic databases from their inception up to December 17, 2017 to examine the efficacy and safety of Chinese herbal medicine for postmenopausal hypertension. Thirty-nine randomized controlled trials involving 3, 823 participants were included. Meta-analyses favored Chinese herbal medicine plus antihypertensive drugs on blood pressure, blood pressure variability, postmenopausal symptoms, quality of life, and hormone levels compared with antihypertensive drugs. No severe adverse effects were identified. Er-xian decoction was the most frequently prescribed herbal formula, while Rehmannia glutinosa Libosch. was the most commonly used single herb. Chinese herbal medicine as complementary therapy maybe beneficial for postmenopausal hypertension. However, the effectiveness and safety of the decoction are still uncertain due to methodological shortcomings. Well-conducted trials are warranted to resolve the issue.


Assuntos
Anti-Hipertensivos/uso terapêutico , Medicamentos de Ervas Chinesas/uso terapêutico , Hipertensão/tratamento farmacológico , Pós-Menopausa , Anti-Hipertensivos/efeitos adversos , Pressão Sanguínea/efeitos dos fármacos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etiologia , Medicamentos de Ervas Chinesas/efeitos adversos , Feminino , Humanos , Medicina Tradicional Chinesa , Fitoterapia
16.
Clin Exp Rheumatol ; 36(5): 791-797, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29600944

RESUMO

OBJECTIVES: Primary gout is a major disease that affects human health; however, its pathogenesis is not well known. The purpose of this study was to identify biomarkers to explore the underlying mechanisms of primary gout. METHODS: We used the isobaric tags for relative and absolute quantitation (iTRAQ) technique combined with liquid chromatography-tandem mass spectrometry to screen differentially expressed proteins between gout patients and controls. We also identified proteins potentially involved in gout pathogenesis by analysing biological processes, cellular components, molecular functions, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and protein-protein interactions. We further verified some samples using enzyme-linked immunosorbent assay (ELISA). Statistical analyses were carried out using SPSS v. 20.0 and ROC (receiver operating characterstic) curve analyses were carried out using Medcalc software. Two-sided p-values <0.05 were deemed to be statistically significant for all analyses. RESULTS: We identified 95 differentially expressed proteins (50 up-regulated and 45 down-regulated), and selected nine proteins (α-enolase (ENOA), glyceraldehyde-3-phosphate dehydrogenase (G3P), complement component C9 (CO9), profilin-1 (PROF1), lipopolysaccharide-binding protein (LBP), tubulin beta-4A chain (TBB4A), phosphoglycerate kinase (PGK1), glucose-6-phosphate isomerase (G6PI), and transketolase (TKT)) for verification. This showed that the level of TBB4A was significantly higher in primary gout than in controls (p=0.023). CONCLUSIONS: iTRAQ technology was useful in the selection of differentially expressed proteins from proteomes, and provides a strong theoretical basis for the study of biomarkers and mechanisms in primary gout. In addition, TBB4A protein may be associated with primary gout.


Assuntos
Proteínas Sanguíneas/análise , Gota/sangue , Gota/diagnóstico , Proteoma , Proteômica/métodos , Adulto , Idoso , Biomarcadores/sangue , Estudos de Casos e Controles , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Ensaio de Imunoadsorção Enzimática , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Mapas de Interação de Proteínas , Espectrometria de Massas em Tandem , Tubulina (Proteína)/sangue
17.
Phys Chem Chem Phys ; 20(23): 15764-15774, 2018 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-29868669

RESUMO

We monitored adsorption of water on a well-defined Fe3O4(111) film surface at different temperatures as a function of coverage using infrared reflection-absorption spectroscopy, temperature programmed desorption, and single crystal adsorption calorimetry. Additionally, density functional theory was employed using a Fe3O4(111)-(2 × 2) slab model to generate 15 energy minimum structures for various coverages. Corresponding vibrational properties of the adsorbed water species were also computed. The results show that water molecules readily dissociate on regular surface Fetet1-O ion pairs to form "monomers", i.e., terminal Fe-OH and surface OH groups. Further water molecules adsorb on the hydroxyl covered surface non-dissociatively and form "dimers" and larger oligomers, which ultimately assemble into an ordered (2 × 2) hydrogen-bonded network structure with increasing coverage prior to the formation of a solid water film.

18.
Angew Chem Int Ed Engl ; 57(5): 1409-1413, 2018 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-29205761

RESUMO

The initial stages of water adsorption on magnetite Fe3 O4 (111) surface and the atomic structure of the water/oxide interface remain controversial. Herein, we provide experimental results obtained by infrared reflection-absorption spectroscopy (IRAS) and temperature-programmed desorption (TPD), corroborated by density functional theory (DFT) calculations showing that water readily dissociates on Fetet sites to form two hydroxo species. These act as an anchor for water molecules to form a dimer complex which self-assembles into an ordered (2×2) structure. Water ad-layer ordering is rationalized in terms of a cooperative effect induced by a hydrogen-bonding network.

19.
Crit Rev Food Sci Nutr ; 57(9): 1831-1851, 2017 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-26167669

RESUMO

Interest is increasing regarding the potential health effects of red yeast rice (RYR) consumption, which is described as a "natural statin" in China. This review aims to evaluate the efficacy of RYR on blood pressure (BP), lipid profile, and C-reactive protein (CRP) in treating hypertension. Seven electronic databases including the Cochrane Central Register of Controlled Trials, EMBASE, PubMed, the Chinese National Knowledge Infrastructure (CNKI), the Chinese Scientific Journal Database (VIP), the Chinese Biomedical Literature Database (CBM), and the Wanfang database were searched. To investigate the role of RYR for hypertension, randomized controlled trials for the use of RYR either as monotherapy or in combination with conventional medicine versus placebo, no intervention, or conventional medicine for hypertension were identified. A total of 21 trials containing 4558 patients were analyzed, the majority of which had low methodological quality. "RYR plus conventional therapy" exhibited significant lowering effects on serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and CRP but exhibited no significant effect on systolic BP, diastolic BP, triglycerides (TG), and high-density lipoprotein cholesterol (HDL-C) compared with "placebo plus conventional therapy." "RYR plus conventional therapy" showed significant lowering effects on systolic BP, TC, LDL-C, and CRP but no effect on diastolic BP, TG, and HDL-C compared with "placebo plus conventional therapy." No significant difference in BP and lipid profile between "RYR plus conventional therapy" and "statins plus conventional therapy" was observed. "RYR plus statins" appeared to be more effective in lowering BP, TC, TG, and LDL-C but without a significant difference in HDL-C compared to statins. No serious adverse events were reported. The results of this meta-analysis suggested some supportive but limited evidence regarding RYR for hypertension. Further rigorously designed trials are warranted before RYR could be recommended to hypertensive patients.


Assuntos
Produtos Biológicos , Pressão Sanguínea/efeitos dos fármacos , Proteína C-Reativa/metabolismo , Suplementos Nutricionais , Hipertensão/metabolismo , Lipídeos/sangue , Humanos , Hipertensão/sangue
20.
J Tradit Chin Med ; 36(2): 135-43, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27400466

RESUMO

OBJECTIVE: To assess the clinical effectiveness and adverse effects of Yinchenwuling powder (YCWLP) in the treatment of hyperlipidemia using Meta-analysis. METHODS: Seven electronic databases were searched for randomized controlled trials designed to evaluate the clinical effectiveness of YCWLP for hyperlipidemia published in any language prior to February 2015. Two reviewers independently identified articles, extracted data, assessed quality, and cross-checked the results. Revman 5.3 was used to analyze the data. RESULTS: Only five randomized controlled trials with poor methodology were included in the analysis. The five trials compared YCWLP with conventional lipid-lowering drugs. Meta-analysis indicated that YCWLP was more effective at the levels of total cholesterol and triglycerides, while increasing the level of high-density lipoprotein cholesterol without serious adverse effects. However, it was not more effective than lipid-lowering drugs in reducing low-density lipoprotein cholesterol and improving hemorheology. CONCLUSION: YCWLP appeared to improve lipid levels. However, given the high risk of bias among the trials, we could not conclude that YCWLP was beneficial to patients with hyperlipidemia. More rigorous trials are required to provide stronger evidence for the conclusion.


Assuntos
Medicamentos de Ervas Chinesas/administração & dosagem , Hiperlipidemias/tratamento farmacológico , Hipolipemiantes/administração & dosagem , Colesterol/metabolismo , Medicamentos de Ervas Chinesas/efeitos adversos , Humanos , Hiperlipidemias/metabolismo , Hipolipemiantes/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Triglicerídeos/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA