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1.
J Clin Periodontol ; 51(8): 1066-1080, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38769711

ABSTRACT

AIM: To examine association between subgingival microbial signatures and levels of cognitive impairment in older adults. MATERIALS AND METHODS: We analysed subgingival plaque samples and 16S ribosomal RNA sequences for microbiota among 165 participants (normal controls [NCs]: 40, subjective cognitive decline [SCD]: 40, mild cognitive impairment [MCI]: 49 and dementia: 36). RESULTS: The bacterial richness was lower among individuals with worse cognitive function, and subgingival microbial communities differed significantly among the four groups. Declining cognitive function was associated with decreasing relative abundance of genera Capnocytophaga, Saccharibacteria_genera_incertae_sedis, Lautropia and Granulicatella, and increasing abundance of genus Porphyromonas. Moreover, there were differentially abundant genera among the groups. Random forest model based on subgingival microbiota could distinguish between cognitive impairment and NC (AUC = 0.933, 95% confidence interval 0.873-0.992). Significant correlations were observed between oral microbiota and sex, Montreal Cognitive Assessment (MoCA) score and Mini-Mental State Examination score. Partial correlation analysis showed that Leptotrichia and Burkholderia were closely negatively associated with the MoCA score after adjusting for multiple covariates. Gene function was not significantly different between SCD and NC groups, whereas three homozygous genes were altered in MCI patients and two in dementia patients. CONCLUSIONS: This is the first study to demonstrate an association between the composition, function and metabolic pathways of subgingival microbiota and different levels of cognitive function among older individuals. Future cohort studies should assess its diagnostic usefulness for cognitive impairment.


Subject(s)
Cognitive Dysfunction , Microbiota , Humans , Aged , Female , Male , Cognitive Dysfunction/microbiology , Dementia/microbiology , Cognition/physiology , RNA, Ribosomal, 16S/analysis , Gingiva/microbiology , Dental Plaque/microbiology , Middle Aged , Aged, 80 and over
2.
J Clin Nurs ; 33(3): 1209-1218, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38284439

ABSTRACT

AIMS AND OBJECTIVES: This study aims to propose a self-management clusters classification method to determine the self-management ability of elderly patients with mild cognitive impairment (MCI) associated with diabetes mellitus (DM). BACKGROUND: MCI associated with DM is a common chronic disease in old adults. Self-management affects the disease progression of patients to a large extent. However, the comorbidity and patients' self-management ability are heterogeneous. DESIGN: A cross-sectional study based on cluster analysis is designed in this paper. METHOD: The study included 235 participants. The diabetes self-management scale is used to evaluate the self-management ability of patients. SPSS 21.0 was used to analyse the data, including descriptive statistics, agglomerative hierarchical clustering with Ward's method before k-means clustering, k-means clustering analysis, analysis of variance and chi-square test. RESULTS: Three clusters of self-management styles were classified as follows: Disease neglect type, life oriented type and medical dependence type. Among all participants, the percentages of the three clusters above are 9.78%, 32.77% and 57.45%, respectively. The difference between the six dimensions of each cluster is statistically significant. CONCLUSION(S): This study classified three groups of self-management styles, and each group has its own self-management characteristics. The characteristics of the three clusters may help to provide personalized self-management strategies and delay the disease progression of MCI associated with DM patients. RELEVANCE TO CLINICAL PRACTICE: Typological methods can be used to discover the characteristics of patient clusters and provide personalized care to improve the efficiency of patient self-management to delay the progress of the disease. PATIENT OR PUBLIC CONTRIBUTION: In our study, we invited patients and members of the public to participate in the research survey and conducted data collection.


Subject(s)
Cognitive Dysfunction , Diabetes Mellitus , Self-Management , Adult , Humans , Aged , Cross-Sectional Studies , Diabetes Mellitus/therapy , Cognitive Dysfunction/complications , Disease Progression
3.
Geriatr Nurs ; 59: 170-180, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-39018961

ABSTRACT

OBJECTIVES: To assess the maintenance effectiveness of a short-period intensive creative expressive arts-based storytelling (SPI-CrEAS) program in older patients with mild cognitive impairment (MCI). METHODS: This two-arm, single-blinded, pilot, randomized controlled trial was conducted at XXX and included 38 participants who had previously completed a 24-week CrEAS project. Eligible participants were randomly assigned to receive intensive CrEAS program twice weekly for an additional 12 weeks (short-period intensive [SPI]-CrEAS) or complete their daily activities (control group). Linear mixed-model regression was used to analyze baseline and intra-group and inter-group comparisons at different follow-up periods. RESULTS: At the 12-week follow-up, verbal function (Verbal Fluency Test, P=0.021) improved significantly in the SPI-CrEAS group compared with the control group. The cognitive benefits of SPI-CrEAS were sustained with twice-weekly training for 3 months, lasting for up to 9 months. CONCLUSIONS: The initial cognitive improvement following CrEAS was sustained at follow-up and boosted by SPI-CrEAS.

4.
Geriatr Nurs ; 60: 137-145, 2024 Sep 07.
Article in English | MEDLINE | ID: mdl-39244799

ABSTRACT

A multimodal exercise training program might be the best way to improve motor and cognitive function in patients with Parkinson's disease (PD), but this has yet to be fully proven in PD patients with mild cognitive impairment (MCI). This study aims to examine the feasibility and effectiveness of a theory-based, multi-component exercise intervention in older people with PD-MCI. Participants were randomized into an intervention group (n=23) and an active control group (n=23), receiving the theory-based multi-component exercise intervention and Parkinson's health exercises, respectively. All participants performed 60-minute exercise training sessions three times a week over a 12-week period. The retention rate at post-intervention was 95.7% (42/46) for the entire cohort. The attendance rates were 99.6% in the intervention group and 99.5% in the control group. No adverse events occurred. The intervention group showed significantly greater improvements than the control group in global cognitive function, executive function, physical motor function, balance and gait, depression, and quality of life. This study indicates that the theory-based multi-component exercise intervention demonstrates high feasibility in promoting exercise adherence and is an effective treatment option for older adults with PD-MCI.

5.
Langmuir ; 39(14): 5230-5237, 2023 Apr 11.
Article in English | MEDLINE | ID: mdl-37000560

ABSTRACT

Boron carbon nitride (BCN) ternary compounds are attractive due to their wide applications in adsorption, catalysis, protective coatings, etc. A simple way is provided to synthesize BCN materials with multistage modulation of hydrophilic-hydrophobic properties. Hydrophilic BCN nanoparticles with a contact angle of 31° and nearly superhydrophobic BCN sheets with a contact angle of 145° are obtained. The participation of a CuO additive in the synthesis process has the role of tuning morphologies, components, and properties of BCN materials. The addition of CuO would improve the hydrophobicity of BCN due to its microstructure with enhanced surface roughness. The interaction between melamine and boric acid on the surface of CuO(111) is investigated by first-principles calculations based on density functional theory (DFT). The tuned BCN materials have different photoelectric properties also, and their performance as photocatalysts has been verified in photocatalytic reactions for hydrogen from water. The achieved uniform hydrophilic BCN nanoparticles and hydrophobic BCN sheets have the potential for further practical applications.

6.
Org Biomol Chem ; 21(7): 1373-1378, 2023 Feb 15.
Article in English | MEDLINE | ID: mdl-36723148

ABSTRACT

A formal [4 + 2] cycloaddition of 3-nitroindoles with ortho-aminophenyl p-quinone methides via a dearomatization process was developed. This method provides a facile approach for preparing tetrahydro-5H-indolo[2,3-b]quinolones with good results. With the bifunctional Cinchona alkaloid-squaramide as the catalyst, the asymmetric version of the reaction successfully afforded the corresponding chiral products with moderate to good enantioselectivities. This work represents the first dearomative cycloaddition of electron-deficient heteroarenes triggered by aza-Michael addition from p-QMs.

7.
BMC Endocr Disord ; 23(1): 240, 2023 Nov 02.
Article in English | MEDLINE | ID: mdl-37919711

ABSTRACT

BACKGROUND: Mild cognitive impairment (MCI) associated with diabetes mellitus (DM) is common among older adults, and self-management is critical to controlling disease progression. However, both MCI and DM are heterogeneous diseases, and existing integrated self-management interventions do not consider patient differences. Grouping patients by disease characteristics could help to individualize disease management and improve the use of available resources. The current study sought to explore the feasibility and effectiveness of a stratified support model for DM-MCI patients. METHODS: Eighty-four DM-MCI patients will be randomly divided into an intervention group and a control group in a 1:1 ratio. The intervention group will receive a self-management intervention using the stratified support pattern-based internet-assisted therapy (SISMT), while the control group will receive the health manual intervention (HMI). The study recruiter will be blinded to the group allocation and unable to foresee which group the next participant will be assigned to. At the same time, the allocation will be also hidden from the research evaluators and participants. After 12 weeks and 24 weeks, cognitive function, blood glucose, self-management ability, psychological status, health literacy, and self-management behavior of patients in both groups will be measured and compared. DISCUSSION: This study developed a stratified support pattern-based internet-assisted to provide self-management intervention for patients with DM-MCI. The impact of different models and forms of self-management intervention on cognitive function, blood glucose management, and psychological status health literacy and self-management behavior of patients will be assessed. The results of this study will inform related intervention research on the stratified support pattern-based internet-assisted self-management therapy, and help to slow the decline of cognitive function in patients with DM-MCI. TRIAL REGISTRATION: ChiCTR2200061991. Registered 16 July 2022.


Subject(s)
Cognitive Dysfunction , Diabetes Mellitus , Self-Management , Humans , Aged , Blood Glucose , Cognitive Dysfunction/therapy , Cognitive Dysfunction/psychology , Internet , Randomized Controlled Trials as Topic
8.
Nutr Neurosci ; : 1-11, 2023 Nov 22.
Article in English | MEDLINE | ID: mdl-37992128

ABSTRACT

Diet can regulate systemic inflammation, which may play an important role in the development and progression of cognitive impairment and dementia. To explore the relationship between the dietary inflammatory potential and cognitive ability. A total of 2307 adults aged 60 years or older were recruited from the Fujian Provincial Hospital (Fujian, China). Dietary inflammatory properties were analyzed using the energy-adjusted dietary inflammatory index (E-DII). The Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) were used to assess cognitive function. Logistic regression and restricted cubic spline (RCS) were fit to assess the associations between variables. The MCI subjects with the highest E-DII scores had a higher risk of AD compared to subjects with the lowest E-DII scores (OR = 1.98, 95%CI = 1.49-2.64, P for trend < 0.001). Subjects with the highest E-DII levels were at increased risk of cognitive impairment compared to those with the lowest E-DII levels (OR = 1.56, 95%CI = 1.25-1.93, P for trend < 0.001). The link between E-DII and cognitive impairment was significant in a nonlinear dose response analysis (P for nonlinear = 0.001). Higher E-DII scores were associated with an increased risk of developing AD or cognitive impairment. These findings may contribute to the effective prevention of cognitive impairment by constructing a multidisciplinary synergistic prevention strategy and controlling dietary inflammation levels.

9.
Sensors (Basel) ; 23(4)2023 Feb 17.
Article in English | MEDLINE | ID: mdl-36850857

ABSTRACT

In a harsh environment, function aggregation of air-ground integrated network service function chaining (SFC) deployment can easily cause network load imbalance, which affects the network security and reliability. In this study, a task-similarity-based virtual network function (VNF) aggregation scheme was proposed. It considered air-ground network resource consumption and load balance before SFC mapping. A model for selecting VNFs to be aggregated based on task similarity was built. The tasks were classified based on their similarity. Furthermore, the VNFs to be aggregated were selected within the class under the constraints of the underlying physical resources. Load balancing was achieved by adjusting the similarity threshold. Moreover, an SFC mapping selection scheme based on network resource awareness was used to obtain the most suitable physical nodes for single-chain and multi-chain mapping according to various attributes of physical network nodes. The simulation results indicated that the proposed scheme with a better load balance design outperformed existing works on VNF aggregation. We also demonstrated that the task-similarity-based scheme was resource-consumption efficient and effective.

10.
Int J Mol Sci ; 24(18)2023 Sep 13.
Article in English | MEDLINE | ID: mdl-37762362

ABSTRACT

Developing highly efficient and multifunctional epoxy resins (EPs) that overcome the shortcomings of flammability and brittleness is crucial for pursuing sustainable and safe application but remains a huge challenge. In this paper, a novel biomass-containing intumescent flame retardant containing a rigid-flexible and multi-siloxane bridge structure (DPB) was synthesized using siloxane; 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO); and biomass vanillin. DPB could facilitate the formation of a carbon residual with an intumescent structure, which effectively blocked the propagation of heat and oxygen. As a result, the peak heat release rate (pHRR) and total heat release (THR) of DPB/EP-7.5 decreased by 38.8% and 45.0%, respectively. In terms of mechanical properties, the tensile and flexural elongations at break of DPB/EP-7.5 increased by 77.2% and 105.3%, respectively. Impressively, DPB/EP-7.5 had excellent dielectric properties, with a dielectric constant of 2.5-2.9. This was due to the Si-O bonds (multi-siloxane bridges) contained in DPB/EP, which can quench the polarization behavior of the hydroxyl group. This paper provides a facile strategy for the preparation of multifunctional EP, which will pave the way for the promotion and application of EP in the high-end field.


Subject(s)
Epoxy Resins , Siloxanes , Animals , Biomass , Carbon , Estrus
11.
Molecules ; 28(14)2023 Jul 12.
Article in English | MEDLINE | ID: mdl-37513227

ABSTRACT

As an important thermosetting material, flame-retardant epoxy resin has various applications in the aerospace, chemical, and electronics industry, and other fields. However, the flame retardancy of epoxy resins is often improved at the expense of mechanical performance. The contradiction between flame retardancy and mechanical properties seriously impedes the practical applications of epoxy resin (EP). Herein, iron-loaded polydopamine functionalized montmorillonite (D-Mt-Fe3+), which was prepared by dopamine, iron chloride and montmorillonite in an aqueous solution, was introduced to prepare iron-loaded polydopamine functionalized montmorillonite/epoxy resin composites (D-Mt-Fe3+/EP). As expected, D-Mt-Fe3+/EP-10 with 10 phr of D-Mt-Fe3+ passed the UL-94 V-0 rating, achieved a limiting oxygen index (LOI) value of 31.0% and reduced the smoke production rate (SPR) and total smoke production (TSP), indicating that the introduction of D-Mt-Fe3+ could endow EP with satisfactory flame retardancy through the radical scavenging function of dopamine in the gas phase and the catalytic charring effect of iron ions, respectively. Encouragingly, the mechanical property was also enhanced with the flexural strength increased by 25.5%. This work provided an attractive strategy for improving both the mechanical properties and fire resistance of EP, which greatly broadened their applications in the chemical industry and electronics field, etc.

12.
Age Ageing ; 51(7)2022 07 01.
Article in English | MEDLINE | ID: mdl-35871420

ABSTRACT

BACKGROUND: Art-based interventions may delay cognitive decline and improve health-related outcomes in older adults with mild cognitive impairment (MCI). OBJECTIVE: To examine the effects of the Creative Expressive Arts-based Storytelling (CrEAS) program compared to active and waitlist controls on neurocognitive and other health-related outcomes in older people with MCI. DESIGN: Three-arm parallel-group, randomised controlled design. PARTICIPANTS: One-hundred and thirty-five adults with MCI (mean age: 70.93 ± 6.91 years). METHODS: Participants were randomly assigned to intervention (CrEAS, n = 45), active control (n = 45) or waitlist control (n = 45) groups. Interventions were applied once per week for 24 weeks. The primary outcome was global cognitive function; secondary outcomes were specific cognition domains (memory, executive function, language and attention) and other health-related outcomes (anxiety, depression and quality of life [QoL]). All variables were measured at baseline (T0), 24-week follow-up (T1) and 48-week follow-up (T2). RESULTS: Participants in the CrEAS group showed significantly higher global cognitive function (adjusted mean difference [MD] = -0.905, 95% confidence interval [CI] -1.748 to -0.062; P = 0.038) and QoL (adjusted MD = -4.150, 95% CI -6.447 to -1.853; P = 0.001) and lower depression symptoms (adjusted MD = 2.902, 95% CI 0.699-5.104; P = 0.011) post-intervention at the 24-week follow-up compared with the active control group. At 48-week follow-up, only the Auditory Verbal Learning Test Immediate recall score was significantly improved compared with the active control group (adjusted MD = -2.941, 95% CI -5.262 to -0.620; P = 0.014). CONCLUSIONS: Older adults with MCI who participated in the CrEAS program improved their neuropsychological outcomes and QoL and reduced their rate of cognitive deterioration.


Subject(s)
Cognition Disorders , Cognitive Dysfunction , Aged , Cognition , Cognitive Dysfunction/diagnosis , Cognitive Dysfunction/psychology , Cognitive Dysfunction/therapy , Executive Function , Humans , Quality of Life
13.
Proc Natl Acad Sci U S A ; 116(37): 18322-18327, 2019 Sep 10.
Article in English | MEDLINE | ID: mdl-31444300

ABSTRACT

Photonic materials with positionally ordered structure can interact strongly with light to produce brilliant structural colors. Here, we found that the nonperiodic nematic liquid crystals of nanoplates can also display structural color with only significant orientational order. Owing to the loose stacking of the nematic nanodiscs, such colloidal dispersion is able to reflect a broad-spectrum wavelength, of which the reflection color can be further enhanced by adding carbon nanoparticles to reduce background scattering. Upon the addition of electrolytes, such vivid colors of nematic dispersion can be fine-tuned via electrostatic forces. Furthermore, we took advantage of the fluidity of the nematic structure to create a variety of colorful arts. It was expected that the concept of implanting nematic features in photonic structure of lyotropic nanoparticles may open opportunities for developing advanced photonic materials for display, sensing, and art applications.

14.
Genomics ; 109(1): 58-66, 2017 01.
Article in English | MEDLINE | ID: mdl-27867104

ABSTRACT

Tea production has been significantly impacted by the false-eye leafhopper, Empoasca vitis (Göthe), around Asia. To identify the key genes which are responsible for nutrition absorption, xenobiotic metabolism and immune response, the transcriptome of either alimentary tracts or bodies minus alimentary tract of E. vitis was sequenced and analyzed. Over 31 million reads were obtained from Illumina sequencing. De novo sequence assembly resulted in 52,182 unigenes with a mean size of 848nt. The assembled unigenes were then annotated using various databases. Transcripts of at least 566 digestion-, 224 detoxification-, and 288 immune-related putative genes in E. vitis were identified. In addition, relative expression of highly abundant transcripts was verified through quantitative real-time PCR. Results from this investigation provide genomic information about E. vitis, which will be helpful in further study of E. vitis biology and in the development of novel strategies to control this devastating pest.


Subject(s)
Digestion/genetics , Hemiptera/genetics , Immune System , Inactivation, Metabolic/genetics , Transcriptome , Animals , Hemiptera/immunology , Hemiptera/metabolism , Hemiptera/physiology , Nymph/genetics
15.
Angew Chem Int Ed Engl ; 57(36): 11752-11757, 2018 Sep 03.
Article in English | MEDLINE | ID: mdl-29987910

ABSTRACT

Dynamically engineering the interfacial interaction of nanoparticles has emerged as a new approach for bottom-up fabrication of smart systems to tailor molecular diffusion and controlled release. Janus zwitterionic nanoplates are reported that can be switched between a locked and unlocked state at interfaces upon changing surface charge, allowing manipulation of interfacial properties in a fast, flexible, and switchable manner. Combining experimental and modeling studies, an unambiguous correlation is established among the electrostatic energy, the interface geometry, and the interfacial jamming states. As a proof-of-concept, the well-controlled interfacial jamming of nanoplates enabled the switchable molecular diffusion through liquid-liquid interfaces, confirming the feasibility of using nanoparticle-based surfactants for advanced controlled release.

16.
Soft Matter ; 13(25): 4457-4463, 2017 Jun 28.
Article in English | MEDLINE | ID: mdl-28580472

ABSTRACT

Mixtures of colloids with different sizes or shapes are ubiquitous in nature and extensively applied in industries. Phase transition pathways and kinetics in this model system should be investigated because of the difficulty in observing tri-phase coexistence in colloidal platelet-sphere mixtures. Similar to the polymer-sphere mixtures, the phase transition pathway has three main categories. Analytical results show a staged phase transition process in which the mixture first separates into one or two metastable phases, then further separates, and subsequently reaches tri-phase equilibrium. Unique to our system, and different from the gas-liquid-crystal coexistence in colloid-polymer mixtures, the platelet-sphere mixture reached a gas-liquid-liquid crystal (nematic) coexistence. Thus, the different phases are easy to distinguish using the birefringence of the liquid crystals. In addition, the volume fraction of the liquid crystal formation in the ZrP platelet suspensions is much lower than for the crystal formation in hard spheres.

17.
Soft Matter ; 13(20): 3789-3793, 2017 May 24.
Article in English | MEDLINE | ID: mdl-28480932

ABSTRACT

Controlling the size polydispersity of colloidal particles is important for their phase transitions, resulting structures, and properties. In this study, a fractionation method was established to control the polydispersity of colloidal plates based on the isotropic-nematic (I-N) phase transition. The size ratio of nanoplates between the N phase and the I phase (DN/DI) was relatively large, whereas the size polydispersities in both the N phase and the I phase were smaller than that of the original sample before fractionation. The degree of fractionation was dependent on the time since the phase transition began and the polydispersity of the original sample. A long time resulted in a small DN/DI and a small degree of polydispersity reduction. The experimental data confirmed a quadratic scaling of DN/DI with polydispersity that was predicted by simulations. Large to small particles were segregated sequentially by sedimentation because of self-assembly and gravity. The polydispersity reduction based on the I-N phase transition can be utilized to select nanoplates with a certain size with improved size monodispersity.

18.
BMC Cancer ; 16: 532, 2016 07 26.
Article in English | MEDLINE | ID: mdl-27461108

ABSTRACT

BACKGROUND: Saikosaponin d (SSd) is one of the main active triterpene saponins in Bupleurum falcatum. It has a steroid-like structure, and is reported to have pharmacological activities, including liver protection in rat, cell cycle arrest and apoptosis induction in several cancer cell lines. However, the biological functions and molecular mechanisms of mammalian cells under SSd treatment are still unclear. METHODS: The cytotoxicity and apoptosis of hepatic stellate cells (HSCs) upon SSd treatment were discovered by MTT assay, colony formation assay and flow cytometry. The collage I/III, caspase activity and apoptotic related genes were examined by quantitative PCR, Western blotting, immunofluorescence and ELISA. The mitochondrial functions were monitored by flow cytometry, MitoTracker staining, ATP production and XF24 bioenergetic assay. RESULTS: This study found that SSd triggers cell death via an apoptosis path. An example of this path might be typical apoptotic morphology, increased sub-G1 phase cell population, inhibition of cell proliferation and activation of caspase-3 and caspase-9. However, the apoptotic effects induced by SSd are partially blocked by the caspase-3 inhibitor, Z-DEVD-FMK, suggesting that SSd may trigger both HSC-T6 and LX-2 cell apoptosis through caspase-3-dependent and independent pathways. We also found that SSd can trigger BAX and BAK translocation from the cytosol to the mitochondria, resulting in mitochondrial function inhibition, membrane potential disruption. Finally, SSd also increases the release of apoptotic factors. CONCLUSIONS: The overall analytical data indicate that SSd-elicited cell death may occur through caspase-3-dependent, caspase-3-independent and mitochondrial pathways in mammalian HSCs, and thus can delay the formation of liver fibrosis by reducing the level of HSCs.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Apoptosis/drug effects , Caspase 3/metabolism , Caspase 9/metabolism , Hepatic Stellate Cells/drug effects , Mitochondria/drug effects , Oleanolic Acid/analogs & derivatives , Saponins/pharmacology , Triterpenes/pharmacology , Animals , Antineoplastic Agents, Phytogenic/therapeutic use , Bupleurum/chemistry , Caspase Inhibitors/pharmacology , Cell Line , Cell Proliferation/drug effects , Drugs, Chinese Herbal/pharmacology , Drugs, Chinese Herbal/therapeutic use , Hepatic Stellate Cells/metabolism , Humans , Liver Cirrhosis/drug therapy , Mitochondria/metabolism , Oleanolic Acid/pharmacology , Oleanolic Acid/therapeutic use , Oligopeptides/pharmacology , Rats , Saponins/therapeutic use , Triterpenes/therapeutic use
19.
Chem Res Toxicol ; 28(1): 43-50, 2015 Jan 20.
Article in English | MEDLINE | ID: mdl-25486454

ABSTRACT

Acrylamide (AA), a rodent carcinogen, is widely used in industry and present in cigarette smoke as well as in foods processed at high temperatures. The metabolic activation of AA to glycidamide (GA) could be critical for AA carcinogenicity since GA causes DNA adduct formation in vivo. N7-(2-carbamoyl-2-hydroxyethyl) guanine (N7-GAG), the most abundant DNA adduct of AA, is subjected to spontaneous and enzymatic depurination and excreted through urine. Urinary N7-GAG analysis can confirm AA genotoxicity and identify active species of AA metabolites in humans, thereby serving as a risk-associated biomarker for molecular epidemiology studies. This study aimed to develop an isotope-dilution solid-phase extraction liquid chromatography tandem mass spectrometry method to comparatively analyze urinary N7-GAG levels in nonsmokers and smokers. Urinary N-acetyl-S-(propionamide)-cysteine (AAMA), a metabolite of AA, was also analyzed as a biomarker for current AA exposure. Urinary N7-GAG was quantified by monitoring m/z 239 → 152 for N7-GAG and m/z 242 → 152 for (13)C3-labeled N7-GAG under positive electron spray ionization and multiple reaction mode. The median urinary N7-GAG level was 0.93 µg/g creatinine in nonsmokers (n = 33) and 1.41 µg/g creatinine in smokers (n = 30). Multiple linear regression analysis of data revealed that N7-GAG levels were only significantly associated with AAMA levels. These results demonstrate that urinary N7-GAG of nonsmokers and smokers is significantly associated with a very low level of dietary AA intake, assessed by analyzing urinary AAMA.


Subject(s)
Acetylcysteine/analogs & derivatives , Acrylamide/metabolism , Carcinogens/metabolism , Cotinine/urine , Guanine/analogs & derivatives , Smoking/urine , Acetylcysteine/urine , Adult , Biomarkers/urine , Diet , Environmental Exposure/analysis , Guanine/urine , Humans , Young Adult
20.
Soft Matter ; 11(28): 5775-9, 2015 Jul 28.
Article in English | MEDLINE | ID: mdl-26095942

ABSTRACT

Mixtures of colloids with different sizes and shapes are ubiquitous in nature and industry. The possible existence of isotropic-isotropic (I1-I2) demixing of platelets and spheres remains an open question. Here we present direct experimental evidence of I1-I2 demixing using platelets with a very small thickness-to-diameter ratio mixed with silica spheres at the size ratio q = R(sphere)/R(disk) = 0.0901 ± 0.0004. The platelets cause the isotropic-to-nematic phase transition at a very low volume fraction because of their highly anisometric shape. The presence of silica spheres in the suspension accelerates the phase transition and packs the nematic phase more densely via depletion interaction. Increasing the sphere volume fraction to 0.0014, a tri-phase region emerges. This direct observation of I1-I2 demixing seems to validate the free-volume scaled particle theory and indicates the need for refinement of the fundamental measure density functional theory.

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