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1.
BMC Gastroenterol ; 23(1): 78, 2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36932326

RESUMO

BACKGROUND: To develop a new modality of colorectal cancer screening based on chronic disease management (CDM) to improve the participation rate of screening, and maximize the benefits of limited resources. METHODS: Patients under CDM were assigned to screening intervention group (SI) and screening control group1 (SC1), residents from natural community were assigned to screening control group2 (SC2). A parallel controlled community intervention study was performed. Only SI would achieve "one-to-one" intervention services. Meanwhile, 200 subjects were selected from each of the three groups for the Knowledge-Attitude-Practice (KAP) questionnaire before and after intervention, named questionnaire intervention group(QI), questionnaire control group1(QC1) and questionnaire control group2(QC2). The outcome of the intervention was evaluated using the difference-in-differences method and multiple regression analysis. RESULTS: The preliminary screening participation rate was 43.63%(473/1084) in SI, 14.32%(132/922) in SCI, and 5.87%(105/1789) in SC2. The baseline questionnaire showed low knowledge scores in the three questionnaire groups with no statistically significant differences, while attitude scores in QI and QC1 were significantly higher than QC2. The differences between baseline and terminal showed QI increased larger in knowledge and attitude scores than QC1 and QC2, while no difference was detected between QC1 and QC2. CONCLUSION: The colorectal cancer screening model based on chronic disease management effectively improved the screening participation rate, and the "one-to-one" intervention and the inherent characteristics of the patient population under CDM were the core elements of the new modality.


Assuntos
Neoplasias Colorretais , Detecção Precoce de Câncer , Humanos , Detecção Precoce de Câncer/métodos , Neoplasias Colorretais/epidemiologia , Conhecimentos, Atitudes e Prática em Saúde , Análise Multivariada , Gerenciamento Clínico , Programas de Rastreamento
2.
Zhongguo Zhong Yao Za Zhi ; 46(17): 4360-4366, 2021 Sep.
Artigo em Zh | MEDLINE | ID: mdl-34581038

RESUMO

Diosgenin is widely distributed in many plants, such as Polygonatum sibiricum, Paris polyphylla, Dioscorea oppositifolia, Trigonella foenum-graecum, Costus speciosus, Tacca chantrieri, which has good anti-tumor activity and preferable effects on preventing atherosclerosis, protecting the heart, treating diabetes, etc. This review combed through the anti-tumor mechanisms of diosgenin encompassing lung, breast, gallbladder, liver, oral cavity, stomach, bladder, bone marrow, etc. Besides, it was discovered that diosgenin mainly exerts its effect by inhibiting tumor cell migration, suppressing tumor cell proliferation and growth, and inducing cell apoptosis. However, problems like low yield and bioavailability frequently exist in natural diosgenin. This review introduced methods such as structural modification, dosage form optimization and combination medication to improve the yield and anti-tumor activity of diosgenin. Via the summary of this paper, it is expected to provide theoretical basis for the rational exploitation and utilization of diosgenin.


Assuntos
Produtos Biológicos , Diosgenina , Trigonella , Apoptose , Proliferação de Células , Diosgenina/farmacologia
3.
Analyst ; 144(2): 426-438, 2019 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-30569916

RESUMO

Paraquat (PQ), a broad-spectrum contact herbicide, has been used in many countries for controlling weed growth in agriculture because of its quick-acting and nonselective contact with green plant tissue. PQ is also toxic to humans, and even contributes to the development of neurodegenerative diseases. However, PQ is generally excluded from pesticide residue monitoring programs due to the lack of suitable determination methods. Thus, this study developed a detection method combined with simple extraction and surface-enhanced Raman spectroscopy (SERS) to rapidly determine and quantify the PQ residue on legumes without destructive procedures and high-cost instruments. Following the extraction procedure of the QuPPe-method, however, we took whole adzuki beans (Vigna angularis) extracted via a mixture of methanol and 1% formic acid at room temperature and followed by a 1 min cleanup by SPE. The PQ values for adzuki beans determined by LC/MSMS showed that regardless of whether extraction was followed by the QuPPe-method or the method we proposed, a consistent and low relative standard deviation (RSD) below <22% was found. In this study, we proposed to extract PQ on the surface of the beans by shaking briefly with solvent, and then the PQ molecules were detected and quantified by depositing Ag nanoparticles (AgNPs) and performing SERS within 10 min. Using a coating of deposited Ag nanoparticles, SERS can achieve a limit of detection (LOD) for PQ on the order of 1 µg L-1 (∼4 × 10-9 M) and a method detection limit (MDL) for adzuki beans of 0.8 µg kg-1 (∼3.3 × 10-9 M). This sensitivity at the ppb level absolutely met the maximum residue limit (MRL) for PQ in dried beans as declared by most countries, including the US (0.3 mg kg-1), Australia (1.0 mg kg-1) and Taiwan (0.2 mg kg-1). Taiwan will ban the use of PQ as a defoliating agent for harvest in adzuki bean fields in 2019; therefore, developing a method for detecting PQ residues in the field or in import markets is necessary for consumer health and for authorities. This study provided an opportunity to utilize SERS in the field of on-site pesticide residue screening.

4.
Nat Commun ; 15(1): 2726, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38548723

RESUMO

Polymeric materials, rich in carbon, hydrogen, and oxygen elements, present substantial fire hazards to both human life and property due to their intrinsic flammability. Overcoming this challenge in the absence of any flame-retardant elements is a daunting task. Herein, we introduce an innovative strategy employing catalytic polymer auto-pyrolysis before combustion to proactively release CO2, akin to possessing responsive CO2 fire extinguishing mechanisms. We demonstrate that potassium salts with strong nucleophilicity (such as potassium formate/malate) can transform conventional polyurethane foam into materials with fire safety through rearrangement. This transformation results in the rapid generation of a substantial volume of CO2, occurring before the onset of intense decomposition, effectively extinguishing fires. The inclusion of just 1.05 wt% potassium formate can significantly raise the limiting oxygen index of polyurethane foam to 26.5%, increase the time to ignition by 927%, and tremendously reduce smoke toxicity by 95%. The successful application of various potassium salts, combined with a comprehensive examination of the underlying mechanisms, underscores the viability of this strategy. This pioneering catalytic approach paves the way for the efficient and eco-friendly development of polymeric materials with fire safety.

5.
Int J Biol Macromol ; 273(Pt 2): 132811, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38825282

RESUMO

Atmospheric drying method for fabricating aerogels is considered the most promising way for casting aerogels on a large scale. However, the organic solvent exchange, remaining environmental pollution risk, is a crucial step in mitigating the impact of surface tension during the atmospheric drying process, especially for wet gel formed through the alkoxy-derived sol-gel process, such as melamine-formaldehyde resin (MF) aerogel. Herein, a tough polymer-assisted in situ polymerization was proposed to fabricate MF resin aerogel with a combination of mechanical toughness and strength, enabling it to withstand the capillary force during water evaporation. The monolithic MF resin aerogel through the sol-gel method can be directly prepared without additional network strengthening or organic solvent exchange. The resulting MF resin aerogel exhibits a homogeneous as well as hierarchical structure with macropores and mesopores (~6 µm and ~5 nm), high compressive modulus of 31.8 MPa, self-extinguishing property, and high-temperature thermal insulation with 97 % heat decrease for butane flame combustion. This work presents a straightforward and environmentally friendly method for fabricating MF resin aerogels with nanostructures and excellent performance in open conditions, exhibiting various applications.


Assuntos
Retardadores de Chama , Géis , Triazinas , Triazinas/química , Géis/química , Pressão , Solventes/química , Resinas Sintéticas/química , Dessecação/métodos , Porosidade , Polimerização
6.
Mater Horiz ; 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38967543

RESUMO

Flexible polyurethane foam (FPUF) is a ubiquitous material utilized in furniture cushions, mattresses, and various technical applications. Despite the widespread use, FPUF faces challenges in maintaining long-lasting flame retardancy and aging resistance, particularly in harsh environments, while retaining mechanical robustness. Here, we present a novel approach to address these issues by enhancing FPUF through multiple free-radical-trapping and hydrogen-bonding mechanisms. A hindered amine phosphorus-containing polyol (DTAP) was designed and chemically introduced into FPUF. The distinctive synergy between hindered amine and phosphorus-containing structures enables the formation of multiple hydrogen bonds with urethane, while also effectively capturing free radicals across a broad temperature spectrum. As a result, incorporating only 5.1 wt% of DTAP led to the material successfully passing vertical burning tests and witnessing notable enhancements in tensile strength, elongation at break, and tear strength. Even after enduring accelerated thermal aging for 168 hours, the foam maintained exceptional flame retardancy and mechanical properties. This study offers novel insights into material enhancement, simultaneously achieving outstanding long-lasting flame retardancy, toughness, and anti-aging performance.

7.
Mater Horiz ; 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38742392

RESUMO

Polyurethane (PU) foams, pivotal in modern life, face challenges suh as fire hazards and environmental waste burdens. The current reliance of PU on potentially ecotoxic halogen-/phosphorus-based flame retardants impedes large-scale material recycling. Here, our demonstrated controllable catalytic cracking strategy, using cesium salts, enables self-evolving recycling of flame-retardant PU. The incorporation of cesium citrates facilitates efficient urethane bond cleavage at low temperatures (160 °C), promoting effective recycling, while encouraging pyrolytic rearrangement of isocyanates into char at high temperatures (300 °C) for enhanced PU fire safety. Even in the absence of halogen/phosphorus components, this foam exhibits a substantial increase in ignition time (+258.8%) and a significant reduction in total smoke release (-79%). This flame-retardant foam can be easily recycled into high-quality polyol under mild conditions, 60 °C lower than that for the pure foam. Notably, the trace amounts of cesium gathered in recycled polyols stimulate the regenerated PU to undergo self-evolution, improving both flame-retardancy and mechanical properties. Our controllable catalytic cracking strategy paves the way for the self-evolutionary recycling of high-performance firefighting materials.

8.
Chin J Integr Med ; 29(5): 424-433, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-35412217

RESUMO

OBJECTIVE: To investigate the effects of composite Sophora colon-soluble Capsule (CSCC) on gut microbiota-mediated short-chain fatty acids (SCFAs) production and downstream group 3 innate lymphoid cells (ILC3s) of dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mice model. METHODS: The main components of CSCC were analyzed by hybrid ultra-high-performance liquid chromatography ion mobility spectromety quadrupole time-of-flight mass spectrometry (UHPLC-IM-QTOF/MS). Twenty-four male BALB/c mice were randomly divided into 4 groups (n=6) by using a computer algorithm-generated random digital, including control, DSS model, mesalazine, and CSCC groups. A DSS-induced colitis mice model was established to determine the effects of CSCC by recording colonic weight, colonic length, index of colonic weight, and histological colonic score. The variations in ILC3s were assessed by immunofluorescence and flow cytometry. The results of gut microbiota and SCFAs were acquired by 16s rDNA and gas chromatography-mass spectrometry (GC-MS) analysis. The expression levels of NCR+ ILC3-, CCR6+ Nkp46- (Lti) ILC3-, and ILCreg-specific markers were detected by enzyme-linked immunosorbent assay, and real-time quantitative polymerase chain reaction and Western blot, respectively. RESULTS: The main components of CSCC were matrine, ammothamnine, Sophora flavescens neoalcohol J, and Sophora oxytol U. After 7 days of treatment, CSCC significantly alleviated colitis by promoting the reproduction of intestinal probiotics manifested as upregulation of the abundance of Bacteroidetes species and specifically the Bacteroidales_S24-7 genus (P<0.05). Among the SCFAs, the content of butyric acid increased the most after CSCC treatment. Meanwhile, compared with the model group, Lti ILC3s and its biomarkers were significantly downregulated and NCR+ ILC3s were significantly elevated in the CSCC group (P<0.01). Further experiments revealed that ILC3s were differentiated from Lti ILC3s to NCR+ ILC3s, resulting in interleukin-22 production which regulates gut epithelial barrier function. CONCLUSION: CSCC may exert a therapeutic effect on UC by improving the gut microbiota, promoting metabolite butyric acid production, and managing the ratio between NCR+ ILC3s and Lti ILC3s.


Assuntos
Colite Ulcerativa , Colite , Microbioma Gastrointestinal , Sophora , Masculino , Animais , Camundongos , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/patologia , Imunidade Inata , Ácido Butírico/metabolismo , Ácido Butírico/farmacologia , Ácido Butírico/uso terapêutico , Linfócitos , Colo , Colite/induzido quimicamente , Colite/metabolismo , Colite/patologia , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL
9.
PLoS One ; 18(10): e0292654, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37862294

RESUMO

Limited research exists regarding the relationship between fasting plasma C-peptide levels and sarcopenia. As a result, our study aimed to examine this association in elderly Chinese diabetic patients. This cross-sectional study included 288 elderly patients with diabetes mellitus from the Fourth People's Hospital in Guiyang who were enrolled prospectively between March 2020 and February 2023. The independent variable of interest was fasting plasma C-peptide, while the dependent variable was sarcopenia. Data on several covariates, including demographic factors, lifestyle habits, co-morbidities, anthropometric indicators, and laboratory indicators, were also collected. Of the 288 participants, 27.43% (79/288) had sarcopenia. After adjusting for potential confounding variables, we found a U-shaped association between fasting plasma C-peptide levels and sarcopenia, with inflection points identified at approximately 774 pmol/L and 939 mmol/L. Within the range of 50-744 pmol/L, each 100 pmol/L increase in CysC was associated with a 37% decrease in the odds of sarcopenia (odds ratio [OR], 0.63; 95% confidence interval [CI], 0.49 to 0.83; P < 0.001). Additionally, within the range of 939-1694 pmol/L, each 100 pmol/L increase in fasting plasma C-peptide was associated with a 76% increase in the odds of sarcopenia (odds ratio [OR], 1.76; 95% confidence interval [CI], 1.11 to 2.81; P = 0.017). Our study revealed a U-shaped association between fasting plasma C-peptide levels and the likelihood of sarcopenia, with lower risk in the range of 774-939 pmol/L. These findings may assist in the development of more effective prevention and treatment strategies for sarcopenia in elderly diabetic patients.


Assuntos
Peptídeo C , Diabetes Mellitus Tipo 2 , Sarcopenia , Idoso , Humanos , China/epidemiologia , Estudos Transversais , População do Leste Asiático , Sarcopenia/sangue , Sarcopenia/complicações , Sarcopenia/epidemiologia
10.
Zhong Xi Yi Jie He Xue Bao ; 10(8): 866-73, 2012 Aug.
Artigo em Zh | MEDLINE | ID: mdl-22883402

RESUMO

OBJECTIVE: To analyze the distribution of traditional Chinese medicine constitution types in elderly patients with insomnia. METHODS: The epidemiological data were collected from communities in the Yangpu District, Shanghai via a cross-sectional field survey. The elderly participants were enrolled by using the Pittsburgh Sleep Quality Index (PSQI) scale and the TCM Constitution Questionnaire. RESULTS: (1)The distribution of imbalanced constitutions between the elderly with insomnia and normal subjects showed statistical difference (P<0.01) and the elderly with insomnia tend to be of imbalanced constitutions. Among these unbalanced constitutions, deficient constitutions were more frequent than others in the elderly with insomnia, and yang-deficiency and qi-deficiency occurred mostly in unbalanced and simple constitutions. (2) Blood-stasis and qi-stagnation constitutions were more frequent in females than in males among the elderly with insomnia. Frequency of deficiency constitutions in the elderly increased as the age increases. (3) The frequency of composite constitutions was higher than that of simple constitutions in elderly patients with insomnia (74.8%), among which qi-deficiency was more likely to be composite with other constitutions. CONCLUSION: Identification and classification of traditional Chinese medicine constitution types will provide further information for devising projects with systematic intervention for insomnia management.


Assuntos
Constituição Corporal , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Idoso , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Medicina Tradicional Chinesa , Pessoa de Meia-Idade
11.
Nat Commun ; 13(1): 7456, 2022 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-36460656

RESUMO

Physicians write clinical notes with abbreviations and shorthand that are difficult to decipher. Abbreviations can be clinical jargon (writing "HIT" for "heparin induced thrombocytopenia"), ambiguous terms that require expertise to disambiguate (using "MS" for "multiple sclerosis" or "mental status"), or domain-specific vernacular ("cb" for "complicated by"). Here we train machine learning models on public web data to decode such text by replacing abbreviations with their meanings. We report a single translation model that simultaneously detects and expands thousands of abbreviations in real clinical notes with accuracies ranging from 92.1%-97.1% on multiple external test datasets. The model equals or exceeds the performance of board-certified physicians (97.6% vs 88.7% total accuracy). Our results demonstrate a general method to contextually decipher abbreviations and shorthand that is built without any privacy-compromising data.


Assuntos
Esclerose Múltipla , Médicos , Trombocitopenia , Humanos , Privacidade , Aprendizado de Máquina , Redação
12.
ACS Appl Mater Interfaces ; 14(48): 54225-54232, 2022 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-36441914

RESUMO

Nylon-cotton (NC) blend fabrics are widely used in military and industrial applications, but their high flammability still remains a serious problem. In an effort to effectively and quickly impart flame retardancy to the NC fabric, it was treated by simply blade coating with a Cu2+-doped polyelectrolyte complex (CPEC) that consists of ammonium polyphosphate (APP), polyethylenimine (PEI), and copper sulfate. The viscosity of the CPEC can be adjusted by altering the content of CuSO4, which controls the amount of extrinsic and intrinsic ion pairs. By adjusting the proportion and content of PEI, APP, and CuSO4, CPEC suitable for treating the NC fabric was obtained. Only 0.067 wt % Cu2+ was needed to adjust the viscosity and impart self-extinguishing behavior in a vertical burning test. This simple two-step treatment provides a promising technology to protect flammable polymeric substrates with ultralow metal-doped polyelectrolyte complexes.

13.
BMJ Health Care Inform ; 29(1)2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36220304

RESUMO

OBJECTIVES: Few machine learning (ML) models are successfully deployed in clinical practice. One of the common pitfalls across the field is inappropriate problem formulation: designing ML to fit the data rather than to address a real-world clinical pain point. METHODS: We introduce a practical toolkit for user-centred design consisting of four questions covering: (1) solvable pain points, (2) the unique value of ML (eg, automation and augmentation), (3) the actionability pathway and (4) the model's reward function. This toolkit was implemented in a series of six participatory design workshops with care managers in an academic medical centre. RESULTS: Pain points amenable to ML solutions included outpatient risk stratification and risk factor identification. The endpoint definitions, triggering frequency and evaluation metrics of the proposed risk scoring model were directly influenced by care manager workflows and real-world constraints. CONCLUSIONS: Integrating user-centred design early in the ML life cycle is key for configuring models in a clinically actionable way. This toolkit can guide problem selection and influence choices about the technical setup of the ML problem.


Assuntos
Aprendizado de Máquina , Design Centrado no Usuário , Atenção à Saúde , Humanos , Dor , Fluxo de Trabalho
14.
ACS Appl Mater Interfaces ; 12(43): 49130-49137, 2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33064444

RESUMO

Most current flame-retardant nanocoatings for flexible polyurethane foam (PUF) consist of passive barriers, such as clay, graphene oxide, or metal hydroxide. In an effort to develop a polymeric and environmentally benign nanocoating for PUF, positively charged chitosan (CH) and anionic sodium hexametaphosphate (PSP) were deposited using layer-by-layer (LbL) assembly. Only six bilayers of CH/PSP film can withstand flame penetration during exposure to a butane torch (∼1400 °C) for 10 s and stop flame spread on the foam. Additionally, cone calorimetry reveals that the fire growth rate, peak heat release rate, and maximum average rate of heat emission are reduced by 55, 43, and 38%, respectively, compared with uncoated foam. This multilayer thin film quickly dehydrates to form an intumescent charred exoskeleton on the surface of the open-celled structure of polyurethane, inhibiting heat transfer and completely eliminating melt dripping. This entirely polymeric nanocoating provides a safe and effective alternative for reducing the fire hazard of polyurethane foam that is widely used for cushioning and insulation.

15.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 4): o712, 2009 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-21582449

RESUMO

In the crystal structure of title compound, C(16)H(14)ClNO(2), the dihedral angle between the aromatic rings is 4.2 (2)°.

16.
Medicine (Baltimore) ; 98(18): e15140, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31045757

RESUMO

RATIONALE: Idiopathic pulmonary fibrosis (IPF) is a special form of spontaneous, chronic, progressive interstitial fibrotic pneumonia of unknown cause, and treatments for IPF have shown a poor prognosis. This study reports a new treatment, traditional Chinese medicine (TCM) therapy, for tonifying Qi-deficiency of lung-kidney in a 64-year-old patient with IPF. PATIENT CONCERNS: A 64-year-old man, who complained of cough and asthma, was diagnosed as IPF with mild impairment in lung function by thoracic high-resolution computed tomography and pulmonary function test. He received an 18-month N-acetylcysteine monotherapy but had no improvement in lung function. DIAGNOSES: IPF with mild impairment in lung function was diagnosed. INTERVENTIONS: The Chinese herbal medicine composition was decocted in 300 ml water for oral administration with 150 ml decoction twice daily in June 2017. OUTCOMES: The pulmonary function test showed that diffusing capacity for carbon monoxide had increased to 81% of predicted back to normal after 2-month TCM monotherapy. And diffusing capacity for carbon monoxide had increased to 89% of predicted, and forced expiratory volume in 1 s/forced vital capacity ratio increased to 92% at 14-month follow-up. No adverse events occurred during the 14 months of therapy and observation. LESSONS: The treatment by TCM therapy of tonifying lung-kidney's Qi-deficiency for IPF can improve the pulmonary function and reverse disease progression; it may be considered as a complementary treatment for IPF with mild-to-moderate impairment. However, the insights provided in this case report require further exploration and verification.


Assuntos
Fibrose Pulmonar Idiopática/terapia , Rim/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Medicina Tradicional Chinesa/métodos , Acetilcisteína/uso terapêutico , Monóxido de Carbono/metabolismo , Progressão da Doença , Expectorantes/uso terapêutico , Volume Expiratório Forçado/efeitos dos fármacos , Humanos , Fibrose Pulmonar Idiopática/diagnóstico por imagem , Fibrose Pulmonar Idiopática/mortalidade , Fibrose Pulmonar Idiopática/fisiopatologia , Rim/fisiopatologia , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Capacidade de Difusão Pulmonar/efeitos dos fármacos , Testes de Função Respiratória/métodos , Resultado do Tratamento , Capacidade Vital/efeitos dos fármacos , Deficiência da Energia Yin
17.
Materials (Basel) ; 12(1)2019 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-30621247

RESUMO

Polypropylene (PP) is currently widely used in areas requiring lightweight materials because of its low density. Due to the intrinsic flammability, the application of PP is restricted in many conditions. Aluminum trihydroxide (ATH) is reported as a practical flame retardant for PP, but the addition of ATH often diminishes the lightweight advantage of PP. Therefore, in this work, glass bubbles (GB) and octacedylamine-modified zirconium phosphate (mZrP) are introduced into the PP/ATH composite in order to lower the material density and simultaneously maintain/enhance the flame retardancy. A series of PP composites have been prepared to explore the formulation which can endow the composite with balanced flame retardancy, good mechanical properties, and low density. The morphology, thermal stability, flame retardancy, and mechanical properties of the composites were characterized. The results indicated the addition of GB could reduce the density, but decreased the flame retardancy of PP composites at the same time. To overcome this defect, ATH and mZrP with synergetic effect of flame retardancy were added into the composite. The dosage of each additive was optimized for achieving a balance of flame retardancy, good mechanical properties, and density. With 47 wt % ATH, 10 wt % GB, and 3 wt % mZrP, the peak heat release rate (pHRR) and total smoke production (TSP) of the composite PP-4 were reduced by 91% and 78%, respectively. At the same time, increased impact strength was achieved compared with neat PP and the composite with ATH only. Maintaining the flame retardancy and mechanical properties, the density of composite PP-4 (1.27 g·cm-3) is lower than that with ATH only (PP-1, 1.46 g·cm-3). Through this research, we hope to provide an efficient approach to designing flame retardant polypropylene (PP) composites with low density.

18.
Carbohydr Polym ; 206: 609-615, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30553364

RESUMO

Self-cross-linked aerogel based on pectin and melamine-formaldehyde resin (MF) was fabricated via freeze-drying method using water as solvent, where pectin is structural material meanwhile acting as acid to catalyse the cross-linking of MF. The cross-linking reaction easily occurs without additional additives, which can be significantly accelerated at elevated temperatures, with a critical value of about 55 °C. The obtained aerogel shows network microstructures as observed with SEM. With increasing pectin content, the aerogel shows significantly increased compressive modulus. The compressive modulus of M10Pe5 arrives 23.2 MPa, the specific modulus of which arrives 188 MPa cm3/g, while pure MF aerogel are too fragile to keep intact after freeze-dried. The resulting aerogel has good thermal stability, excellent water resistance (can be second dried with limited strength loss) and low flammability. This partially bio-based novel aerogel with impressive properties is promising in many applications.

19.
Bioresour Technol ; 272: 92-98, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30316196

RESUMO

Functional carbon materials have been fabricated through simple and effective catalytic carbonization with waste coffee grounds (CGs) as carbon precursor and FeCl3 as catalyst. The effect of FeCl3 loading and carbonization temperature on carbon yield was investigated. The morphology and structure of as-synthesized carbons was characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and nitrogen isothermal adsorption/desorption measurement, respectively. Furthermore, the carbon materials showed high efficiency for the removal of methylene blue (MB, 653.6 mg g-1), methyl orange (MO, 465.8 mg g-1) and rhodamine B (RB, 366.1 mg g-1). More importantly, the carbon was magnetic, so it can be easily separated by a magnet and reused multiple times. This work not only exploited a low-cost and large-scale preparation method to synthesize functional carbon materials from bioresources, but also provided an eco-friendly and effective adsorbent in water purification applications.


Assuntos
Carbono/química , Café/química , Adsorção , Compostos Azo/química , Compostos Azo/isolamento & purificação , Corantes/química , Imãs , Azul de Metileno/química , Azul de Metileno/isolamento & purificação , Poluentes Químicos da Água/química
20.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 10): o1968, 2008 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-21201168

RESUMO

In the title compound, C(15)H(13)Cl(2)NO(2), the dihedral angle between the aromatic rings is 27.17 (11)°. In the crystal the molecules are linked by N-H⋯O hydrogen bonds.

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