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1.
Nature ; 623(7986): 340-346, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37853124

RESUMEN

Understanding the effects of cash crop expansion on natural forest is of fundamental importance. However, for most crops there are no remotely sensed global maps1, and global deforestation impacts are estimated using models and extrapolations. Natural rubber is an example of a principal commodity for which deforestation impacts have been highly uncertain, with estimates differing more than fivefold1-4. Here we harnessed Earth observation satellite data and cloud computing5 to produce high-resolution maps of rubber (10 m pixel size) and associated deforestation (30 m pixel size) for Southeast Asia. Our maps indicate that rubber-related forest loss has been substantially underestimated in policy, by the public and in recent reports6-8. Our direct remotely sensed observations show that deforestation for rubber is at least twofold to threefold higher than suggested by figures now widely used for setting policy4. With more than 4 million hectares of forest loss for rubber since 1993 (at least 2 million hectares since 2000) and more than 1 million hectares of rubber plantations established in Key Biodiversity Areas, the effects of rubber on biodiversity and ecosystem services in Southeast Asia could be extensive. Thus, rubber deserves more attention in domestic policy, within trade agreements and in incoming due-diligence legislation.


Asunto(s)
Conservación de los Recursos Naturales , Bosques , Mapeo Geográfico , Goma , Imágenes Satelitales , Asia Sudoriental , Biodiversidad , Nube Computacional , Conservación de los Recursos Naturales/estadística & datos numéricos , Conservación de los Recursos Naturales/tendencias
2.
Cardiovasc Drugs Ther ; 36(6): 1109-1119, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34491473

RESUMEN

PURPOSE: Abdominal aortic aneurysm (AAA) rupture is one of the most common causes of mortality in cardiovascular diseases, but currently there is no approved drug for AAA treatment or prevention in the clinic. Naringenin (NGN) has been reported to have anti-AAA effects. However, water solubility and in vivo absorption of NGN are not satisfactory, which leads to its low bioavailability, thus affecting its pharmacological effects. In this project, the improving effects of isonicotinamide (INT) co-crystal and hydroxy propyl methyl cellulose (HPMC) or polyvinyl pyrrolidone (PVP) on the solubility, in vivo absorption, and anti-AAA effects of NGN were evaluated. METHODS: In the current study, co-crystals of naringenin-isonicotinamide (NGN-INT) were prepared, and effects of PVP or HPMC on precipitation rate, supersaturation, and bioavailability of NGN were explored. In addition, with or without HPMC supply, the effects of NGN-INT co-crystal on anti-AAA efficacy of NGN were investigated on an elastase-induced AAA mouse model, and the results were compared with the efficacy of the NGN crude drug. RESULTS: Our results demonstrate that NGN-INT formulation, compared to the NGN crude drug, enhanced the dissolution rate of NGN and significantly increased Cmax and AUC(0-∞) of NGN by 18 times and 1.97 times, respectively. Addition of PVP or HPMC in NGN-INT co-crystal further increased bioavailability of NGN in NGN-INT. The in vivo pharmacodynamic study showed that NGN-INT with HPMC significantly improved the inhibitory effects of NGN against AAA. CONCLUSION: NGN-INT significantly improved the absorption and aortic protective effects of NGN. The supersaturation-prolonging effect of HPMC further enhanced bioavailability and anti-AAA effects of NGN-INT.


Asunto(s)
Aneurisma de la Aorta Abdominal , Ratones , Animales , Aneurisma de la Aorta Abdominal/tratamiento farmacológico , Aneurisma de la Aorta Abdominal/prevención & control , Derivados de la Hipromelosa/química , Solubilidad , Povidona/química
3.
Angew Chem Int Ed Engl ; 56(19): 5308-5311, 2017 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-28378362

RESUMEN

By coating chloroplasts with conjugated polymer nanoparticles (CPNs), a new bio-optical hybrid photosynthesis system (chloroplast/CPNs) is developed. Since CPNs possess unique light harvesting ability, including the ultraviolet part that chloroplasts absorb less, chloroplast/CPN complexes can capture broader range of light to accelerate the electron transport rates in photosystem II (PS II), the critical protein complex in chloroplasts, and augment photosynthesis beyond natural chloroplasts. The degree of spectral overlay between emission of CPNs and absorption of chloroplasts is critical for the enhanced photosynthesis. This work exhibits good potential to explore new and facile nanoengineering strategy for reforming chloroplast with light-harvesting nanomaterials to enhance solar energy conversion.


Asunto(s)
Cloroplastos/metabolismo , Nanopartículas/química , Complejo de Proteína del Fotosistema II/metabolismo , Polímeros/química , Cloroplastos/química , Fluorescencia , Estructura Molecular , Nanopartículas/metabolismo , Tamaño de la Partícula , Fotosíntesis , Complejo de Proteína del Fotosistema II/química , Polímeros/metabolismo
4.
Postgrad Med ; 136(1): 30-35, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38197225

RESUMEN

OBJECTIVES: Morning dry mouth, commonly seen in Obstructive Sleep Apnea (OSA) patients, is absent in current OSA screening tools. This study evaluated the link between morning dry mouth and OSA's clinical symptoms and complications, aiming to determine its viability as a screening indicator. METHODS: This research analyses baseline data from a prospective cohort study (the PIFCOPD study). Demographic information, medical history, and the presence of morning dry mouth symptoms were collected. The STOP-Bang questionnaire was performed for OSA screening. Logistic regression analyses were employed to establish the correlations between morning dry mouth and the clinical symptoms and comorbidities of OSA. RESULT: 1291 participants (62.1±7.5 years; 501 males, 790 females) were included, of which 416 reported morning dry mouth (32.2%). 42.6% in the high-risk OSA group and 22.1% in the low-risk group reported morning dry mouth. Individuals with morning dry mouth also showed higher STOP-Bang scores (3.3±1.6 vs. 2.3±1.4, P<0.01). Significant associations were found between morning dry mouth and loud snoring, observed sleep apnea, daytime fatigue, and hyperlipidemia (P<0.01), but not with alcohol consumption, tea consumption, diabetes, or hypertension. CONCLUSION: Morning dry mouth is associated with increased OSA risk and its clinical signs, suggesting its potential as an OSA screening symptom. CLINICAL TRIAL REGISTRATION: This study has been registered at www.ClinicalTrials.gov (registration identifier: NCT03532893) on 21 May 2018.


Asunto(s)
Apnea Obstructiva del Sueño , Xerostomía , Masculino , Femenino , Humanos , Estudios Transversales , Estudios Prospectivos , Comorbilidad , Encuestas y Cuestionarios , Apnea Obstructiva del Sueño/epidemiología , Apnea Obstructiva del Sueño/complicaciones , Xerostomía/epidemiología , Xerostomía/complicaciones , Tamizaje Masivo
5.
Scand J Gastroenterol ; 48(2): 213-7, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23234601

RESUMEN

BACKGROUND: Currently, there is no consensus on the recommendation of peginterferon alfa (pegIFNα) to chronic hepatitis B (CHB) patients with poor viral response (EVR). This study aimed to assess the sustained curative efficacy of adefovir (ADV) add-on therapy in optimizing pegIFNα monotherapy. METHODS: A total of 85 hepatitis B e antigen (HBeAg)-positive CHB patients with poor virological response at month 6 after starting pegIFNα-2a were enrolled, and received either pegIFNα-2a continuing monotherapy (group A, n = 51) or add-on therapy with ADV (group B, n = 34). The treatment duration for all patients was 6 months, and the sustained responses after the end of treatment were evaluated between two groups. RESULTS: The baseline characteristics were comparable between two groups. At months 6 after treatment completion, the sustained virological response (SVR) rates were 31.4% and 73.5%, the sustained biochemical response (SBR) rates were 39.2% and 85.3% in group A and group B respectively, and the difference in either SVR or SBR was statistically significant (both p < 0.001). As compared to patients in group A, significantly more patients in group B obtained HBeAg loss (19.6% vs. 55.9%, p = 0.001) and seroconversion (13.7% vs. 41.2%, p = 0.004). CONCLUSION: ADV add-on therapy could significantly improve and sustain the curative efficacy of CHB patient with poor virological response to pegIFNα-2a monotherapy, but further large well-designed randomized controlled trials are needed to confirm our findings.


Asunto(s)
Adenina/análogos & derivados , Antivirales/uso terapéutico , Hepatitis B Crónica/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Organofosfonatos/uso terapéutico , Polietilenglicoles/uso terapéutico , Adenina/uso terapéutico , Adulto , Biomarcadores/sangre , Esquema de Medicación , Quimioterapia Combinada , Femenino , Antígenos e de la Hepatitis B/sangre , Hepatitis B Crónica/sangre , Hepatitis B Crónica/virología , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Proteínas Recombinantes/uso terapéutico , Resultado del Tratamiento , Carga Viral
6.
Chem Commun (Camb) ; 58(77): 10853-10856, 2022 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-36073502

RESUMEN

Bio-organic hybrid self-assemblies based on amino acids, conjugated polymers, Fe3+ and enzymes are fabricated with tumor environment-responsive and light-triggered NO release properties. By sequential energy consumption, NO attack and immune activation, FFPG shows boosted antitumor activity toward both primary and distant tumors. The three-level cascade strategy (starvation/NO/immunotherapy) adopted in this work offers a pathway to address the dilemma of low cure rate of malignant tumors.


Asunto(s)
Nanopartículas , Neoplasias , Aminoácidos , Línea Celular Tumoral , Humanos , Inmunoterapia , Nanopartículas/química , Neoplasias/terapia , Polímeros/química
7.
J Zhejiang Univ Sci B ; 23(9): 778-783, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36111574

RESUMEN

To increase the efficiency and accuracy of clinical tumor detection, we explored multiple imaging by preparing carbon quantum dot (CQD)-loaded nanobubbles for ultrasonic fluorescence dual detection. In this experiment, we prepared 1,2-dioleoyl3-trimethylammonium-propane chloride (DOTAP) cationic liposomes using the film dispersion method and chose perfluoropentane as the core gas material of the nanobubbles. The nanobubbles were coupled with the negatively charged CQDs through the charge effect to prepare the testing agent for two-way diagnosis with ultrasound contrast and fluorescence detection. The formulation and preparation of the loaded CQD liposome nanobubbles were screened. In vivo experiments showed that nanobubbles can be enriched to the tumor site within 5 min, which enables clearer ultrasound imaging and is conducive to tumor detection. We expect CQD-loaded liposome (Lip-CQD) nanobubbles to become a new ultrasonic contrast agent for clinical applications that can provide a basis for early tumor diagnosis and thus earlier treatment.


Asunto(s)
Neoplasias , Puntos Cuánticos , Carbono , Cloruros , Medios de Contraste , Fluorescencia , Humanos , Liposomas , Neoplasias/diagnóstico , Propano , Ultrasonido
8.
Adv Healthc Mater ; 9(2): e1901492, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31800169

RESUMEN

The difficulty in killing tumor cells due to the tendency to metastasis and drug resistance are outstanding and urgent problems for the treatment of cancer. It is imperative to figure out an effective therapy strategy to break the treatment dilemmas. Nano self-assembly has the characteristics of flexible regulation, biological compatibility, and easy access. Herein, an albumin-polymer nano-assembly with switchable cytotoxicity and reactive oxygen species (ROS) amplification capability is developed for anti-tumor therapy. The nano-assembly (PFFBT@HSA) is comprised of conjugated polymer PFFBT and natural protein human serum albumin (HSA) via the hydrophobic and electrostatic interactions. The innovative switchable strategy is proposed and realized by HSA turning off the cytotoxicity of PFFBT and then turning on and enhancing the cytotoxicity by generating massive ROS upon light irradiation. The combination of HSA provides more stable microenvironment to benefit the generation of highly effective anti-tumor model of "0+1>1". These results display that the nanostructured self-assembly and the proposed anti-tumor regulation strategy are effective, which will contribute to the diversified treatment of cancer.


Asunto(s)
Antineoplásicos/química , Antineoplásicos/farmacología , Nanopartículas/química , Polímeros/química , Animales , Femenino , Células HeLa , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Luz , Ratones Endogámicos BALB C , Especies Reactivas de Oxígeno/química , Albúmina Sérica Humana/química , Espectrometría de Fluorescencia , Ensayos Antitumor por Modelo de Xenoinjerto
9.
ACS Appl Mater Interfaces ; 12(19): 21254-21262, 2020 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-31909588

RESUMEN

Bacterial infections induced by drug-resistant strains have become a global crisis. A membrane-disrupted mechanism is considered as an effective way to kill bacteria with little chance to trigger drug resistance. It is necessary to explore and develop new materials based on the membrane-disrupted mechanism to combat bacterial resistance. Here we report the design of organic nanoparticles based on a polymer (PDCP) as highly effective inhibition and bactericidal reagents. The PDCP is devised to have a hydrophobic skeleton and hydrophilic side chain modified with protonated primary amines, which could self-assemble to form organic nanoparticles (PDCP-NPs). By taking advantage of the large surface to volume ratio of nanoparticles, the synthesized PDCP-NPs have enriched positive charges and multiple membrane-binding sites. Research results display that PDCP-NPs have highly potent antibacterial activity in vitro and vivo, especially for Gram-negative bacteria with low toxicity against mammalian cells. This work design will inspire researchers to develop more membrane-disrupted bactericide and advance the applications of organic nanoparticles in the antibacterial area.


Asunto(s)
Aminas/uso terapéutico , Antibacterianos/uso terapéutico , Nanopartículas/uso terapéutico , Polímeros/uso terapéutico , Infecciones Estafilocócicas/tratamiento farmacológico , Aminas/síntesis química , Aminas/toxicidad , Animales , Antibacterianos/síntesis química , Antibacterianos/toxicidad , Línea Celular Tumoral , Membrana Celular/efectos de los fármacos , Femenino , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Klebsiella pneumoniae/efectos de los fármacos , Ratones Endogámicos BALB C , Pruebas de Sensibilidad Microbiana , Nanopartículas/química , Nanopartículas/toxicidad , Polímeros/síntesis química , Polímeros/toxicidad , Pseudomonas aeruginosa/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos
10.
ACS Appl Mater Interfaces ; 12(35): 39685-39694, 2020 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-32805886

RESUMEN

Diseases induced by bacterial infections increasingly threaten the health of people all over the world; thus, it is urgent and significant to early diagnose and effectively eliminate infections to save people's lives. To this end, we synthesized an intelligent hydrogel that integrated in situ visualized diagnosis and photothermal therapy of bacterial infections. By simply and subtly incorporating pH-sensitive bromothymol blue (BTB) and near-infrared (NIR)-absorbing conjugated polymer (termed as PTDBD) into thermosensitive chitosan (CS)-based hydrogel, the synthesized BTB/PTDBD/CS hydrogel can diagnose the acidic microenvironment of Staphylococcus aureus (S. aureus) biofilm and infected wounds by showing visualized color change. After rapid diagnosis, the hydrogel can immediately treat the infection site by local hyperthermia under irradiation of NIR laser (808 nm) and even the stubborn biofilm that is difficult to eradicate. Since the dominating antibacterial mechanism is hyperthermia, the hybrid hydrogel shows broad-spectrum antibacterial activity against Gram-positive, Gram-negative, and drug-resistant bacteria. In addition, it has low cytotoxicity to normal cells and no effect on the main organs of mice. It paves a brand new avenue to develop smart and facile diagnosis and a treatment platform for bacterial infections.


Asunto(s)
Antibacterianos/química , Hidrogeles/química , Rayos Infrarrojos , Terapia Fototérmica , Infecciones Estafilocócicas/terapia , Animales , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Azul de Bromotimol/química , Supervivencia Celular/efectos de los fármacos , Quitosano/química , Farmacorresistencia Bacteriana/efectos de los fármacos , Humanos , Hidrogeles/farmacología , Concentración de Iones de Hidrógeno , Hipertermia Inducida , Masculino , Ratones , Ratones Endogámicos BALB C , Polímeros/química , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/fisiología
11.
Biomater Sci ; 7(9): 3788-3794, 2019 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-31218306

RESUMEN

Photodynamic therapy (PDT) has been reported to be an effective alternative to combat bacterial infections even those triggered by drug-resistant strains as there is little chance to develop resistance to this therapy. Therefore, it is imperative to design and synthesize a superior photo-active bactericide for the treatment of bacterial infections. Herein, we synthesized three bactericidal activity-tunable conjugated polymers (P1-P3) with various photoactive capabilities and employed them for the treatment of wound infections with little damage to cells; by altering the construction unit of π-conjugated backbone structures with electron-rich and electron-deficient aromatic heterocycles, the optical properties and ability of reactive oxygen species (ROS) generation could be regulated; this resulted in a tunable killing ability. The cationic quaternary ammonium (QA) groups on the side chains endowed the CPs with not only good dispersibility but also a better interaction with the negatively charged membrane of bacteria. The antibacterial experiments towards ampicillin-resistant Escherichia coli TOP10 (E. coli) and the treatment of wound infections in mice indicate that the P1-P3 have varied bactericidal activities; moreover, P3 has been demonstrated to be a human-friendly bactericide with excellent antibacterial capability. It not only acts as a potential bactericide for the practical treatment of infectious wounds, but also offers guidance for the design and structure control of photo-active bactericides.


Asunto(s)
Ampicilina/farmacología , Antibacterianos/farmacología , Escherichia coli/efectos de los fármacos , Polímeros/farmacología , Compuestos de Amonio Cuaternario/farmacología , Infección de Heridas/tratamiento farmacológico , Ampicilina/química , Antibacterianos/química , Farmacorresistencia Bacteriana/efectos de los fármacos , Humanos , Pruebas de Sensibilidad Microbiana , Fotoquimioterapia , Polímeros/química , Compuestos de Amonio Cuaternario/química
12.
Biomater Sci ; 7(12): 5528-5534, 2019 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-31659356

RESUMEN

Antibiotic residues can induce the production of bacterial variability and increase the variety of resistant bacterial strains. In order to cope up with the global crisis, there is an urgent need to develop alternative drugs and strategies to effectively kill the bacteria and inhibit the emergence of superbugs. Herein, we developed an antibacterial strategy based on the conjugated polymer nanoparticles (CPNs) and the biomolecule-mediated regulation for the controllable antibacterial treatment. Upon being modified with Hoechst 33258 (H33258), the biocompatible CPNs tend to be effective antibacterial agents, with the antibacterial activity being regulated through the binding and separation of H33258 and calf thymus double-stranded DNA (dsDNA) with the aid of deoxyribonuclease I (DNase I). This eco-friendly antibacterial system not only provides a simple and controllable antibacterial strategy but also inspires the design of biomolecule-mediated antibacterial activity regulation.


Asunto(s)
Antibacterianos/administración & dosificación , Bisbenzimidazol/química , Infecciones por Escherichia coli/tratamiento farmacológico , Polímeros/administración & dosificación , Animales , Antibacterianos/síntesis química , Antibacterianos/química , Antibacterianos/farmacología , ADN/efectos de los fármacos , Modelos Animales de Enfermedad , Farmacorresistencia Bacteriana/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Femenino , Tecnología Química Verde , Ratones , Nanocáscaras , Polímeros/síntesis química , Polímeros/química , Polímeros/farmacología
13.
Adv Mater ; 30(8)2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29327394

RESUMEN

Remote control and noninvasive manipulation of cellular bioprocess has received intensive attention as a powerful technology to control cell functions. Here, a strategy is developed to remotely control intracellular gene expression with high spatial and temporal resolutions by using photothermal-responsive conjugated polymer nanoparticles (CPNs) as the transducer under near-infrared light irradiation. After being modified with positive charged peptide, the CPNs with superior photothermal conversion capacity could effectively coat on the surface of living cells and generate localized heat to trigger target gene expression. The heat-inducible heat shock protein-70 promoter starts transcription of downstream EGFP gene in response to heat shock, thus producing green fluorescent protein in the living cells. The combination of heat-inducible gene promoter and photothermal-responsive CPNs provides a method for the development of thermogenetics.


Asunto(s)
Nanopartículas , Supervivencia Celular , Calor , Rayos Infrarrojos , Fototerapia , Polímeros
14.
ACS Appl Mater Interfaces ; 7(43): 24110-8, 2015 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-26451624

RESUMEN

A new water-soluble conjugated poly(fluorene-co-phenylene) derivative (PFP-FB) modified with boronate-protected fluorescein (peroxyfluor-1) via PEG linker has been designed and synthesized. In the presence of H2O2, the peroxyfluor-1 group can transform into green fluorescent fluorescein by deprotecting the boronate protecting groups. In this case, upon selective excitation of PFP-FB backbone at 380 nm, efficient fluorescence resonance energy transfer (FRET) from PFP-FB backbone to fluorescein occurs, and accordingly, the fluorescence color of PFP-FB changes from blue to green. Furthermore, the emission color of PFP-FB and the FRET ratio change in a concentration-dependent manner. By taking advantage of PFP-FB, ratiometric detection of choline and acetylcholine (ACh) through cascade enzymatic reactions and further dynamic monitoring of the choline consumption process of cancer cells have been successfully realized. Thus, this new polymer probe promotes the development of enzymatic biosensors and provides a simpler and more effective way for detecting the chemical transmitter of living cells.


Asunto(s)
Peróxido de Hidrógeno/química , Neoplasias/patología , Polímeros/química , Espectrometría de Fluorescencia/métodos , Acetilcolina/química , Técnicas Biosensibles , Línea Celular Tumoral , Colina/química , Transferencia Resonante de Energía de Fluorescencia , Colorantes Fluorescentes/química , Células HeLa , Humanos , Células Jurkat , Neoplasias/metabolismo , Sensibilidad y Especificidad , Solubilidad , Espectrofotometría Ultravioleta , Agua/química
15.
Shanghai Kou Qiang Yi Xue ; 22(4): 432-7, 2013 Aug.
Artículo en Zh | MEDLINE | ID: mdl-24100904

RESUMEN

PURPOSE: To explore the relations between Streptococcus sobrinus (S. Sobrinus) and rampant caries in children. METHODS: Based on previous investigation result for rampant caries in Zhengzhou city, 66 children aged 3-5 years were selected by random sampling, and divided into 3 groups of rampant caries, high dental caries and no caries, 22 cases in each group. The final identification of S. mutans and S. sobrinus were performed after using culture medium TYCSB to operate preliminary screening of Streptococcus mutans (S. Mutans) and S. Sobrinus with polymerase chain reaction(PCR) combined with physiological and biochemical identification. SPSS10.0 software package was used to compare the detection rate and mean values of S.mutans and S.sobrinus in the experimental group and the control group. RESULTS: It was found that single S. sobrinus without S. mutans was not detected from dental plaque in each group. The detection rate of S. mutans in group of rampant caries was higher than in group of high dental caries, but there was no significant difference (P>0.05). The difference of detection rate of S. sobrinus between the two groups and the detection rate of S. mutans between group of rampant caries and group without caries was significant(P<0.05). The difference of the detection rate of S. sobrinus between group of rampant caries and group without caries was also significant(P<0.01). The incidence of rampant caries, DMFT, DMFS, smooth-surface caries among the sample with both of S. sobrinus and S. mutans detected and the sample only with S. mutans and the sample without S. sobrinus and S. mutans were significantly different (P<0.01). CONCLUSIONS: The main pathogenic bacteria of rampant caries in children are S. mutans and S. sobrinus. The incidence of rampant caries was related to S. sobrinus, which had synergic effect on the occurrence and development of rampant caries in children.


Asunto(s)
Caries Dental , Streptococcus sobrinus , Preescolar , Placa Dental , Humanos , Reacción en Cadena de la Polimerasa , Streptococcus mutans
16.
Chemosphere ; 82(4): 621-6, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21071063

RESUMEN

The potential health and environmental hazards of carbon nanotubes (CNTs) have been a concerned issue. However, in contrast to the wide recognition of the toxicity of CNTs, little attention has been paid to the decontamination/remediation of CNT pollution. In this study, we report that CNTs can be removed from aqueous environment. In the presence of Ca²(+), CNTs aggregate quickly to micron size and then enable easy and effective removal via normal filtration. After filtration, CNT suspension becomes colorless with the remnant CNT concentration less than 0.5 µg mL⁻¹, a safe dose based on the published data. The filtration approach also works well in the presence of typical surfactant and dissolved organic matter. The removal efficiency is Ca²(+) concentration-dependent and regulated by the initial pH value and ionic strength. Our study is helpful for future decontamination of CNTs from aqueous environment.


Asunto(s)
Filtración/métodos , Nanotubos de Carbono/química , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos , Adsorción , Concentración de Iones de Hidrógeno , Microscopía Electrónica de Transmisión , Nanotubos de Carbono/análisis , Nanotubos de Carbono/ultraestructura , Concentración Osmolar , Papel , Polisorbatos/química , Contaminantes Químicos del Agua/análisis
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