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1.
Biomed Res Int ; 2022: 2742274, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36277892

RESUMO

Computer tomography is an extensively used method for the detection of the disease in the subjects. Basically, computer-aided tomography depending on the artificial intelligence reveals its significance in smart health care monitoring system. Owing to its security and the private issue, analyzing the computed tomography dataset has become a tedious process. This study puts forward the convolutional autoencrypted deep learning neural network to assist unsupervised learning technique. By carrying out various experiments, our proposed method produces better results comparative to other traditional methods, which efficaciously solves the issues related to the artificial image description. Hence, the convolutional autoencoder is widely used in measuring the lumps in the bronchi. With the unsupervised machine learning, the extracted features are used for various applications.


Assuntos
Aprendizado Profundo , Humanos , Inteligência Artificial , Redes Neurais de Computação , Aprendizado de Máquina não Supervisionado , Tomografia Computadorizada por Raios X
2.
Comput Intell Neurosci ; 2022: 4437507, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36225550

RESUMO

The Internet of Things (IoT) is legitimately growing quicker. The operators have already started setting up a diligent infrastructure for these gadgets. Various technologies need to be developed for this type of sensor, including enterprise safety initiatives. This paper covers the stability routing protocol, which assumes an assessment of credibility in gadgets and packet flow. To build reliable Software-Defined Network (SDN) routes, build on the trust between network element flows and Quality of Service (QoS) or energy conditions. The SDN architecture is used for the Cognitive Protocol Network (CPN) technical platform to increase the energy level. Stochastic Neural Networks (SNNs) are accredited with information extracted from perceptual packets and make decentralized decisions. The proposed network infrastructure is designed and integrated into the SerIoT techniques to strengthen IoT encryption for information access control. The versatility of the technology is to circumvent the unpredictable connectivity of the system and the node decreases in terms of potential cryptographic capacity, limited interval, a target node, and deterministic energy. Based on factual statistical data, appropriate marketing generates an end-to-end antitheft solution that meets a set of predetermined circuit restrictions. A study must collaborate by demonstrating numerous flaws due to the obvious instability of clusters, which is essential for the efficiency of the platform.


Assuntos
Internet das Coisas , Redes Neurais de Computação , Software
3.
Mater Sci Eng C Mater Biol Appl ; 109: 110427, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32228983

RESUMO

Bone defects in load bearing areas require bone reconstruction with strong biomaterial having mechanical characteristics like cortical bone. Bioceramics are biomaterials that support bone formation as well as provide adequate mechanical properties. A strontium substitution of the bioceramic is expected to further increase its bioactivity by enhancing osteogenesis and protect the bone from osteoclastic resorption. The study involves development, characterization and in vivo testing of a newly developed strontium substituted hydroxyapatite based bioceramic scaffold (SrHAB) with sufficient biomechanical properties. Optimal concentration of strontium ion required for enhanced osteogenic differentiation was identified by comparing three compositions of SrHAB scaffold; namely Sr10HAB, Sr30HAB and Sr50 HAB for their Alkaline phosphatase activity in vitro. The selected Sr10HAB scaffold demonstrated in vivo bone formation with osteogenic differentiation of stromal derived mesenchymal stem cells (MSC) from human and ovine sources in ectopic and ovine models. Thus, Sr10HAB scaffold has a potential for application in load bearing bone requirements of orthopaedics and dentistry.


Assuntos
Cerâmica/química , Osteogênese/fisiologia , Estrôncio/química , Tecidos Suporte/química , Fosfatase Alcalina/metabolismo , Animais , Regeneração Óssea/fisiologia , Linhagem Celular , Proliferação de Células/fisiologia , Sobrevivência Celular/fisiologia , Células Cultivadas , Humanos , Microscopia Eletrônica de Varredura , Ovinos , Espectroscopia de Infravermelho com Transformada de Fourier , Suporte de Carga/fisiologia
4.
Microb Pathog ; 141: 104029, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32014462

RESUMO

The human body is a reservoir of numerous micro-creatures; whose role is substantial and indispensable in the overall development of human beings. The advances in omic approaches have offered powerful means to decipher the core microbiome and metabolome diversities in a specific organ system. The establishment of lactobacilli in the female reproductive tract is thought to be a paramount prerequisite that maintains homeostatic conditions for a sustainable and healthy pregnancy. Nevertheless, a plethora of such Lactobacillus strains of vaginal source revealed probiotic phenotypes. The plummeting in the occurrence of lactobacilli in the vaginal ecosystem is associated with several adverse pregnancy outcomes (APOs). One such pathological condition is "Bacterial Vaginosis" (BV), a pathogen dominated gynecological threat. In this scenario, the ascending traffic of notorious Gram-negative/variable BV pathogens to the uterus is one of the proposed pathways that give rise to inflammation-related APOs like preterm birth. Since antibiotic resistance is aggravating among urogenital pathogens, the probiotics intervention remains one of the alternative biotherapeutic strategies to overcome BV and its associated APOs. Perhaps, the increased inclination towards the safer and natural biotherapeutic strategies rather than pharmaceutical drugs for maintaining gestational and reproductive health resulted in the use of probiotics in pregnancy diets. In this context, the current review is an attempt to highlight the microbiome and metabolites signatures of BV and non-BV vaginal ecosystem, inflammation or infection-related preterm birth, host-microbial interactions, role and effectiveness of probiotics to fight against aforesaid diseased conditions.


Assuntos
Nascimento Prematuro/etiologia , Probióticos/uso terapêutico , Vagina/microbiologia , Vaginose Bacteriana/complicações , Antibacterianos/uso terapêutico , Suplementos Nutricionais , Resistência a Medicamentos , Disbiose/tratamento farmacológico , Feminino , Bactérias Anaeróbias Gram-Negativas/efeitos dos fármacos , Homeostase , Humanos , Recém-Nascido , Lactobacillus , Interações Microbianas , Microbiota/efeitos dos fármacos , Gravidez , Saúde Reprodutiva
5.
Sci Total Environ ; 712: 135214, 2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-31836221

RESUMO

Chemical characterisation of atmospheric aerosols over Arabian Sea (AS) and Indian Ocean (IO) have been carried out during the winter period (January to February 2018) as part of the Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB-2018). Mass concentrations of organic carbon (OC), elemental carbon (EC), water soluble and insoluble OC (WSOC, WIOC), primary and secondary OC (POC, SOC), water-soluble inorganic ions and trace metals have been estimated with a view to identify and quantify the major anthropogenic pollutants affecting the oceanic environments. Aerosol mass loading was found to exhibit strong spatial heterogeneity (varying from 13 to 84 µg m-3), significantly modulated by the origin of air-mass trajectories. Chemical analysis of aerosols revealed the presence of an intense pollution plume over south-eastern coastal Arabian Sea, near to south-west Indian peninsula (extending from ~ 12°N to 0° at 75°E) with a strong latitudinal gradient (~3 µg m-3/deg. from north to south) dominated by anthropogenic species contributing as high as 73% (38% nss-SO42-, 24.2% carbonaceous aerosols (21% Organic Matter, 3.2% EC) and 10% NH4+). Anthropogenic signature over oceanic environment was also evident from the dominance and high enrichment of elements like Zn, Cu, Mn and Pb in trace metals. Long-range transport of air-masses originating from Indo Gangetic Plains and its outflow regions in Bay of Bengal, has been seen over Arabian Sea during winter, that imparted such strong anthropogenic signatures over this oceanic environment. Comparison with previous cruise studies conducted nearly two decades ago shows a more than two-fold increase in the concentration of nss-SO42-, over the continental outflow region in Arabian Sea.

6.
Sci Total Environ ; 656: 1261-1279, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30625656

RESUMO

Near-surface atmospheric aerosols (PM10) collected from a tropical coastal location in south-west peninsular Indian region for a duration of 6 years (2012-18) (N = 461) were analysed for carbonaceous aerosol components, the less studied aerosol species. Organic carbon (OC), its water soluble-insoluble (WSOC and WIOC) components, primary-secondary (POC and SOC) fractions and elemental carbon (EC) were examined for understanding the annual, seasonal, day-night variations in abundance pattern along with associated physical and meteorological processes. Total carbonaceous aerosols accounting for 36% of the collected aerosol mass with 31.5% organic matter (OM) and 4.5% EC respectively, exhibited consistent seasonal pattern throughout the study period with high concentration during winter followed by post-monsoon, pre-monsoon and monsoon. Delineation of marine and continental components of carbonaceous species based on their relative dominance during different air-mass periods, shows that while marine aerosols were a combination of natural sources comprising of volatile, semi-volatile species and secondary organics (from marine VOC precursors); the continental aerosols were composed of anthropogenic combustion sources (fossil fuel, biomass emissions etc). Based on the measurements of OC and EC during 2005-09 and 2012-18, their long term trends (for more than a decade) were investigated. Although OC showed an increasing tendency, EC exhibited a decrease with the total carbonaceous aerosols exhibiting a gradual decreasing trend over the years, indicating that they do not strictly reverberate the reported increasing trend observed over north-central parts of India. This can be presumed to be due to the reduced anthropogenic inputs over the location owing to the control measures and policies. The strong convective activity and large scale monsoon phenomena also helps in the effective dispersion of pollutants. Making use of comprehensive measurement of carbonaceous aerosols and the previous measurements of other aerosol components, an improved chemical composition model is presented.

7.
Sci Total Environ ; 631-632: 1472-1485, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29727971

RESUMO

In view of the large uncertainties in the methane (CH4) emission estimates and the large spatial gaps in its measurements, studies on near-surface CH4 on regional basis become highly relevant. This paper presents the first time observational results of a study on the impacts of mesoscale meteorology on the temporal variations of near-surface CH4 at a tropical coastal station, in India. It is based on the in-situ measurements conducted during January 2014 to August 2016, using an on-line CH4 analyzer working on the principle of gas chromatography. The diurnal variation shows a daytime low (1898-1925ppbv) and nighttime high (1936-2022ppbv) extending till early morning hours. These changes are closely associated with the mesoscale circulations, namely Sea Breeze (SB) and Land Breeze (LB), as obtained through the meteorological observations, WRF simulations of the circulations and the diurnal variation of boundary layer height as observed by the Microwave Radiometer Profiler. The diurnal enhancement always coincides with the onset of LB. Several cases of different onset timings of LB were examined and results presented. The CH4 mixing ratio also exhibits significant seasonal patterns being maximum in winter and minimum in pre-monsoon/monsoon with significant inter-annual variations, which is also reflected in diurnal patterns, and are associated with changing synoptic meteorology. This paper also presents an analysis of in-situ measured near-surface CH4, column averaged and upper tropospheric CH4 retrieved by Atmospheric Infrared Sounder (AIRS) onboard Earth Observing System (EOS)/Aqua which gives insight into the vertical distribution of the CH4 over the location. An attempt is also made to estimate the instantaneous radiative forcing for the measured CH4 mixing ratio.

8.
Environ Sci Pollut Res Int ; 25(15): 14827-14843, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29541985

RESUMO

This paper presents the first observational results from an Indian station on the long-term changes in surface ozone (O3)-a major environmental pollutant and green house gas-over a period of about 40 years. It is based on the in situ measurements carried out during 1973-1975, 1983-1985, 1997-1998 and 2004-2014 at the tropical coastal station, Thiruvananthapuram. From 1973 to 1997, surface O3 shows a slow increase of ~ 0.1 ppb year-1 and a faster increase of 0.4 ppb year-1 afterwards till 2009 after which it showed a levelling off till 2012 followed by a minor decrease. The highest rate of increase is observed during 2005 to 2009 (2 ppb year-1), and the overall increase from 1973 to 2012 is ~ 10 ppb. The increase in day time O3 (peak O3) is estimated as 0.42 ppb year-1 during 1997-2012 and 2.93 ppb year-1 during 2006-2012. Interestingly, the long-term trend in O3 showed seasonal dependence which is more pronounced during O3 peaking seasons (winter/summer). The observed trends were analysed in the light of the changes in NO2, a major outcome of anthropogenic activities and methane which has both natural and anthropogenic sources and also meteorological parameters. Surface O3 and NO x exhibited positive association, but with varying rate of increase of O3 for NO x < 4 and > 4 ppb. Methane, a precursor of O3 also showed increase in tune with O3. Unlike many other high-latitude locations, meteorology plays a significant role in the long-term trends in O3 at this tropical site with water vapour abundance and strong solar irradiance which favour photochemistry. A comparison with the corresponding changes in the satellite-retrieved tropospheric column O3 (TCO) also showed an increase of 0.03 DU year-1 during 1996-2005 which enhanced to 0.12 DU year-1 after 2005. Both surface O3 and satellite-retrieved TCO were positively correlated with daily maximum temperature, increasing at the rate of 1.54 ppb °C-1 and 1.9 DU °C-1, respectively, on yearly basis. Surface O3 is found to be negatively correlated with water vapour content (ρv) at this tropical site, but at higher levels of ρv, O3 shows a positive trend.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Ozônio/análise , Tempo (Meteorologia) , Monitoramento Ambiental/métodos , Índia , Ozônio/química , Estações do Ano , Temperatura , Clima Tropical
9.
Indian J Nephrol ; 26(6): 408-412, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27942171

RESUMO

The aim of this study was to establish a limited sample strategy (LSS) to predict the mycophenolic acid (MPA) area under the curve (AUC)(0-12) in children with systemic lupus erythematosus (SLE). Three months after initiation of mycophenolate mofetil (MMF) 26 children with SLE presented for therapeutic drug monitoring of MPA. On the day of the test, 10 specimens were collected, analyzed, and MPA AUC(0-12) was calculated. Using step-wise regression analysis, LSS equations were developed. Using bootstrap validation, the predictive performance was calculated. The measured mean (standard deviation) for the trough concentration and AUC(0-12) were 2.55 (1.57) µg/ml and 62.6 (21.67) mg.h/L, respectively. The range of trough concentrations and AUC(0-12) were 0.7-5.54 µg/ml and 22.1-104.8 mg.h/L, respectively. The interindividual variability (%CV) for dose normalized AUC(0-12) and dose normalized Ctrough was 46.5% and 61.1%, respectively. The correlation between the concentrations at the different time points and MPA AUC(0-12) ranged from 0.05 (1.5 h) to 0.56 (4 h). Two LSS equations that included 4 or 5 time points up to 3 h were developed and validated. The 4 point LSS had a correlation (R2) of 0.88 and the 5 point LSS an R2 of 0.87. With respect to the 4 point and 5 point MPA LSS AUC(0-12), the bias was 1.92% and 1.96%, respectively, and the imprecision was 11.24% and 11.28%, respectively. A 4 point LSS which concludes within 3 h after the administration of the MMF dose was developed and validated, to determine the MPA AUC(0-12) in children with SLE.

10.
Environ Sci Pollut Res Int ; 22(19): 14901-18, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25994269

RESUMO

As part of the Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB) conducted under the Geosphere Biosphere Programme of Indian Space Research Organisation, ship-based aerosol sampling was carried out over the marine environment of Bay of Bengal (BoB) during the northern winter months of December 2008 to January 2009. About 101 aerosol samples were collected, covering the region from 3.4° to 21° N latitude and 76° to 98° E longitude-the largest area covered-including the south east (SE) BoB for the first time. These samples were subjected to gravimetric and chemical analysis and the total aerosol loading as well the mass concentration of the ionic species namely F(-), Cl(-), Br(-), NO2 (-), NO3 (-), PO4 (2-), SO4 (2-), NH4 (+), etc. and the metallic species, Na, Mg, Ca, K, Al, Fe, Mn, Zn, and Pb were estimated for each sample. Based on the spatial distribution of individual chemical species, the air flow pattern, and airmass back trajectory analysis, the source characteristics of aerosols for different regions of BoB were identified. Significant level of continental pollution was noticed over BoB during winter. While transport of pollution from Indo-Gangetic Plain (IGP) contributed to aerosols over north BoB, those over SE BoB were influenced by SE Asia. A quantitative study on the wind-induced production of sea salt aerosols and a case study on the species dependent effect of rainfall are also presented in this paper.


Assuntos
Poluentes Atmosféricos/análise , Metais Pesados/análise , Aerossóis , Baías , Monitoramento Ambiental , Índia , Chuva , Estações do Ano
12.
3 Biotech ; 4(1): 91-95, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28324466

RESUMO

In pathogenic bacteria, identification of essential proteins which are non-homologous to the host plants represents potential antimicrobial targets. We applied subtractive genomics approach for the identification of novel antimicrobial targets in Xanthomonas oryzae pv. oryzae PXO99A, the causative agent of bacterial blight in rice. Comparative analysis was performed through BLAST available with the NCBI. The analysis revealed that 27 essential protein sequences out of 4,988 sequences of X. oryzae pv. oryzae PXO99A are non-homologous to Oryza sativa. Subsequent analysis of 27 essential proteins revealed their involvement in different metabolic activities such as transport activity, DNA binding, structural constituent of ribosome, cell division, translation, and plasma membrane. These 27 proteins were analyzed for virulence and novelty and out of 27, three essential non-homologous proteins were found to be the novel antimicrobial targets.

13.
Hum Exp Toxicol ; 32(7): 706-20, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23155198

RESUMO

Polychlorinated biphenyls (PCBs) comprise a ubiquitous class of toxic substances associated with carcinogenic and tumor-promoting effects as well as neurotoxic properties. Reactive oxygen species, which is produced from PCBs, alters blood-brain barrier (BBB) integrity, which is paralleled by cytoskeletal rearrangements and redistribution and disappearance of tight junction proteins (TJPs) like claudin-5 and occludin. Quercetin, a potent antioxidant present in onion and other vegetables, appears to protect brain cells against oxidative stress, a tissue-damaging process associated with Alzheimer's and other neurodegenerative disorders. The aim of this study is to analyze the role of quercetin on oxidative stress markers and transcription of transmembrane and cytoplasmic accessory TJPs on cerebrum, cerebellum and hippocampus of female rats exposed to PCBs. Rats were divided into the following four groups. Group I: received only vehicle (corn oil) intraperitoneally (i.p.); group II: received Aroclor 1254 at a dose of 2 mg/kg body weight (bwt)/day (i.p); group III: received Aroclor 1254 (i.p.) and simultaneously quercetin 50 mg/kg bwt/day through gavage and group IV: received quercetin alone gavage. From the experiment, the levels of hydrogen peroxide, lipid peroxidation and thiobarbituric acid reactive substances were observed to increase significantly in cerebrum, cerebellum and hippocampus as 50%, 25% and 20%, respectively, after exposure to PCB, and the messenger RNA expression of TJP in rats exposed to PCBs is decreased and is retrieved to the normal level simultaneously in quercetin-treated rats. Hence, quercetin can be used as a preventive medicine to PCBs exposure and prevents neurodegenerative disorders.


Assuntos
Encéfalo/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Fármacos Neuroprotetores/farmacologia , Bifenilos Policlorados/toxicidade , Quercetina/farmacologia , Animais , Encéfalo/metabolismo , Feminino , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Proteínas de Junções Íntimas/genética
14.
Neurol India ; 60(2): 146-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22626693

RESUMO

BACKGROUND AND OBJECTIVES: Monitoring of levetiracetam in routine clinical practice is not strongly recommended. The aim of this study was to investigate any difference in serum levetiracetam concentration between patients on enzyme-inducing and -inhibiting antiepileptic co-medication and also to identify any correlation between levetiracetam concentration and clinical response. MATERIALS AND METHODS: This study included pediatric patients with epilepsy from a tertiary care referral hospital in India. Details of antiepileptic co-medication, seizure frequency before and after initiating levetiracetam were recorded. Serum trough levetiracetam concentration was measured. RESULTS: Of the 69 children recruited in the study, 55 children had >50% reduction in seizure frequency compared to baseline seizure frequency. Eight patients showed no improvement. The serum concentration of levetiracetam was more than 10 µg/ml in 78.2% of responders and 75% non-responders. There was no difference in dosing between responders and non-responders. Patients on enzyme-inducing co-medication had lower median serum levetiracetam concentrations (7.3 µg/ml) compared to those on enzyme-inhibiting co-medication (14.4 µg/ml) or those without interfering antiepileptic co-medication (16.6 µg/ml). CONCLUSION: Levetiracetam monitoring has a role in patients on antiepileptic polypharmacy and for confirmation of compliance.


Assuntos
Anticonvulsivantes/administração & dosagem , Monitoramento de Medicamentos/métodos , Epilepsia/tratamento farmacológico , Piracetam/análogos & derivados , Adolescente , Anticonvulsivantes/sangue , Criança , Pré-Escolar , Humanos , Índia , Lactente , Levetiracetam , Cooperação do Paciente , Piracetam/administração & dosagem , Piracetam/sangue
15.
Auton Autacoid Pharmacol ; 32(1 Pt 2): 15-22, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22372564

RESUMO

The atypical opioid analgesic tramadol has been shown to provide beneficial clinical and urodynamic effects in patients with detrusor overactivity. The effect of tramadol on isolated detrusor muscle has not been studied. This study investigated the ability of tramadol to inhibit acetylcholine (ACh)-induced contractility of the isolated caprine (goat) detrusor muscle. The effect of three concentrations (30, 100 and 300 µm) of tramadol on 10 caprine detrusor strips contracted by the addition of 100, 200 or 400 µm ACh was studied. The sensitivity of tramadol-induced inhibition of ACh responses to treatment with the ß-adrenoceptor antagonist propranolol (1 µm) and the opioid receptor antagonist naloxone (100 µm) was also studied. Tramadol caused a concentration-dependent inhibition of ACh-induced detrusor contraction that was reversed by raising the concentration of ACh. Propranolol, but not naloxone, reversed the tramadol-induced inhibition of contractions to ACh in the detrusor. These results suggest that tramadol inhibits ACh-induced contractility of the isolated detrusor. They also suggest that tramadol does so by an indirect anticholinergic mechanism involving the stimulation of ß-adrenoceptors. Tramadol may be useful in managing clinical conditions requiring relaxation of the detrusor muscle. Although the concentrations of tramadol needed to relax the detrusor were relatively high, these could be clinically attained via intravesical administration.


Assuntos
Relaxamento Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Tramadol/farmacologia , Bexiga Urinária/efeitos dos fármacos , Animais , Cabras , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Relaxamento Muscular/fisiologia , Músculo Liso/fisiologia , Técnicas de Cultura de Órgãos , Bexiga Urinária/fisiologia
16.
Crit Care Resusc ; 10(2): 137-9, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18522528

RESUMO

Severe septicaemia secondary to melioidosis carries a high mortality. Although melioidosis can involve most tissues and organs, pericardial involvement is rare. We report a 40-yearold woman with melioidosis with pericardial involvement but no contiguous pulmonary involvement. She developed acute pericardial tamponade but was successfully treated with surgery and medical therapy. This is the first case in Australia or New Zealand of melioid sepsis presenting with pericarditis and subsequent cardiac tamponade. We review the literature on cardiac involvement in melioidosis.


Assuntos
Burkholderia pseudomallei/isolamento & purificação , Tamponamento Cardíaco/etiologia , Melioidose/microbiologia , Derrame Pericárdico/complicações , Sepse/microbiologia , Adulto , Antibacterianos/uso terapêutico , Tamponamento Cardíaco/diagnóstico , Tamponamento Cardíaco/cirurgia , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Melioidose/diagnóstico , Melioidose/terapia , Derrame Pericárdico/diagnóstico , Derrame Pericárdico/microbiologia , Sepse/diagnóstico , Sepse/terapia , Toracotomia/métodos , Tomografia Computadorizada por Raios X
17.
J Colloid Interface Sci ; 240(2): 630-635, 2001 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-11482974

RESUMO

Aggregation behavior in aqueous solution of a series of poly (ethylene glycol) (PEG)-based macromonomers with methacryloyl group as the only hydrophobic segment has been investigated using surface tension, steady-state and time-resolved fluorescence spectroscopy using pyrene as a probe, and small-angle neutron scattering techniques. The general formula of these macromonomers is CH(2)&dbond;C(CH(3))-CO-O-E(m)-CH(3), where E is the ethylene glycol unit and m=8 (ME(8)), 18 (ME(18)), 49 (ME(49)), and 120 (ME(120)). The results indicate that a macromonomer with 8 ethylene glycol units forms as an aggregate above a certain critical concentration, which can be defined as critical aggregation concentration. The observed high value of I(1)/I(3) in pyrene emission spectra at the interface of these aggregates and the inability to scatter a neutron beam by these aggregates indicate that the hydrophobic cluster formed by this macromonomer is remarkably solvated. ME(18) has a tendency to aggregate but others do not form any hydrophobic cluster. The homopolymerization behaviors of these macromonomers in an aqueous medium at 70 degrees C are consistent with these possibi- lities. Copyright 2001 Academic Press.

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