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2.
Food Chem ; 441: 138362, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38219362

RESUMO

This Schiff base chemosensor (SNN) detected dual ions, Al3+ and Zn2+ ions selectively. Fluorescence spectrum investigations showed that Al3+ ions increased fluorescence intensity, notably at 493 nm. Introducing Zn2+ ions caused a significant blue shift of roughly ∼65 nm at a wavelength of 434 nm, resulting in a notable change in fluorescence intensity. When binding Al3+/Zn2+ ions, the SNN receptor uses three methods. Inhibition of photoinduced electron transfer (PET), excited state intramolecular proton transfer (ESIPT), and restriction of CN isomerization. The jobs plot method found that SNN + Al3+ and SNN + Zn2+ complexations had a 1:1 stoichiometry. DFT, LC-HRMS, and 1H NMR titration confirm this conclusion. The probe SNN's limit of detection (LOD) for Al3+/Zn2+ ions was 3.99 nM and 1.33 nM. Latent fingerprint (LFP), food samples, pharmaceutical products, and E. coli pathogen bio-imaging have all used the SNN probe to identify Al3+ and Zn2+ ions.


Assuntos
Aldeídos , Escherichia coli , Corantes Fluorescentes , Corantes Fluorescentes/química , Íons , Prótons , Zinco/análise , Espectrometria de Fluorescência/métodos
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 288: 122196, 2023 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-36473294

RESUMO

Anthracene based chemosensor ABC has been synthesized and characterized through 1H, 13C NMR, mass spectral studies. UV absorption and emission studies performed to identify the sensing behavior of chemosensor ABC. The probe ABC, originally bright fluorescent, selectively sense Ag+ ion by the quenching the fluorescence intensity through a "Switch On-off" process and quench the fluorescence due to the heavy atom effect interaction with the free chemosensor. The binding constant of the probe ABC with Ag+ was calculated as 5.4 × 104 M-1 and the limit of detection upto 1.4 nM level. The practical utilization of the probe ABC was demonstrated by applying to the real water and soil sample analysis, latent finger print, and the sensor as a fluorescent ink.


Assuntos
Benzeno , Bases de Schiff , Espectrometria de Fluorescência , Bases de Schiff/química , Corantes Fluorescentes/química , Fluorometria , Antracenos
4.
Comput Math Methods Med ; 2022: 8571970, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36132548

RESUMO

The level of patient's illness is determined by diagnosing the problem through different methods like physically examining patients, lab test data, and history of patient and by experience. To treat the patient, proper diagnosis is very much important. Arrhythmias are irregular variations in normal heart rhythm, and detecting them manually takes a long time and relies on clinical skill. Currently machine learning and deep learning models are used to automate the diagnosis by capturing unseen patterns from datasets. This research work concentrates on data expansion using augmentation technique which increases the dataset size by generating different images. The proposed system develops a medical diagnosis system which can be used to classify arrhythmia into different categories. Initially, machine learning techniques like Support Vector Machine (SVM), Naïve Bayes (NB), and Logistic Regression (LR) are used for diagnosis. In general deep learning models are used to extract high level features and to provide improved performance over machine learning algorithms. In order to achieve this, the proposed system utilizes a deep learning algorithm known as Convolutional Neural Network-baseline model for arrhythmia detection. The proposed system also adopts a novel hyperparameter tuned CNN model to acquire optimal combination of parameters that minimizes loss function and produces better result. The result shows that the hyper-tuned model outperforms other machine learning models and CNN baseline model for accurate classification of normal and other five different arrhythmia types.


Assuntos
Aprendizado Profundo , Algoritmos , Arritmias Cardíacas/diagnóstico por imagem , Teorema de Bayes , Eletrocardiografia , Humanos , Aprendizado de Máquina , Máquina de Vetores de Suporte
5.
Food Chem ; 395: 133617, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-35802967

RESUMO

Dimeric quinoline-based Schiff base was developed (DQS) for the specific detection of Pb2+ ion via fluorimetry. DQS coordinates with Pb2+, a variation in fluorescence intensity with enhanced radical blue shift was observed due to the restriction of CN rotation, CN isomerization, and photoinduced electron transfer (PET) mechanisms. In addition, the intramolecular charge transfer (ICT) from electron-donating morpholine to phenylene diamine acceptor linked quinoline bridge is responsible for the blue-shifted fluorescence enhancement in the DQS-Pb2+ complex. The binding stoichiometry of DQS: Pb2+ (1:2) was confirmed by host-guest titration and mass spectrometry. The limit of detection (LOD) of the DQS was found to be 1.3 × 10-7 M for Pb2+ ion. The DQS sensing ability of Pb2+ was further applied into milk and honey samples, smartphone, bio-imaging and to construct of an INHIBIT molecular logic gate.


Assuntos
Mel , Quinolinas , Corantes Fluorescentes/química , Chumbo , Quinolinas/química , Smartphone , Espectrometria de Fluorescência/métodos
6.
Comput Math Methods Med ; 2022: 7672196, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35116074

RESUMO

SARS-CoV-2 is a novel virus, responsible for causing the COVID-19 pandemic that has emerged as a pandemic in recent years. Humans are becoming infected with the virus. In 2019, the city of Wuhan reported the first-ever incidence of COVID-19. COVID-19 infected people have symptoms that are related to pneumonia, and the virus affects the body's respiratory organs, making breathing difficult. A real-time reverse transcriptase-polymerase chain reaction (RT-PCR) kit is used to diagnose the disease. Due to a shortage of kits, suspected patients cannot be treated promptly, resulting in disease spread. To develop an alternative, radiologists looked at the changes in radiological imaging, like CT scans, that produce comprehensive pictures of the body of excellent quality. The suspected patient's computed tomography (CT) scan is used to distinguish between a healthy individual and a COVID-19 patient using deep learning algorithms. A lot of deep learning methods have been proposed for COVID-19. The proposed work utilizes CNN architectures like VGG16, DeseNet121, MobileNet, NASNet, Xception, and EfficientNet. The dataset contains 3873 total CT scan images with "COVID" and "Non-COVID." The dataset is divided into train, test, and validation. Accuracies obtained for VGG16 are 97.68%, DenseNet121 is 97.53%, MobileNet is 96.38%, NASNet is 89.51%, Xception is 92.47%, and EfficientNet is 80.19%, respectively. From the obtained analysis, the results show that the VGG16 architecture gives better accuracy compared to other architectures.


Assuntos
COVID-19/diagnóstico , COVID-19/patologia , Aprendizado Profundo , Conjuntos de Dados como Assunto , Humanos , Pandemias , Tomografia Computadorizada por Raios X/métodos
7.
Ann Oncol ; 32(Suppl 2)2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34220400

RESUMO

Background: Glucocorticoid receptor (GR) is shown to have variable frequency of expression in invasive tumors of the breast. Investigation of additional nuclear receptors like GR in receptor negative tumors like triple negative breast cancer (TNBC) may have prognostic and therapeutic significance. Methods: Expression of GR was evaluated by immunohistochemistry in 175 tumors of invasive breast cancer with long term follow up. GR Expression was separately evaluated in invasive tumor cells, stromal cells and tumor infiltrating lymphocytes (TIL's). Staining pattern was categorised as positive when more than 1% of the cells stained in each subpopulation of cells. Disease free survival was analysed between GR positive and negative status by Kaplan Meier analysis. Results: Of the 175 tumors, 121 (70%) were ER positive, 53 (30%) were ER negative and 29% (51) were triple negative. 74% (130/175) tumors showed expression of GR in invasive tumor cells while (84%) 147/175 had expression in TIL's. No significant difference in distribution of GR was noted between ER positive and ER negative tumors (78% vs 66%, p-0.1). Of the TNBC's 54% (28/51) and 70% (36/51) showed expression of GR in invasive tumor and TIL's respectively. Overall, GR positive tumors had significant better survival than GR negative tumors (mean survival time of 85 vs 59 months respectively, p-0.04) Contrary to the reports that GR expression in TIL's are associated with immunosuppressive activity in model systems, TNBC's with increased expression of GR in immune cells were associated with better survival (Mean survival time 74 vs 41 months, log rank test- p-0.03). TNBC tumors which were GR negative had higher lymph node metastases (p-0.04) and none of the other clinical features like age, menopausal state, tumor size and grade were different between GR positive and negative tumors within TNBC. Conclusions: Glucocorticoids (GC) are often used to alleviate the adverse symptoms during chemotherapy. Determining the GR status is of importance due to the pro cell survival effect of the glucocorticoids mediated through GR during chemotherapy. Though GC mediated effects on chemotherapy are controversial, our results indicate favourable effects in TNBC.

8.
Food Chem ; 348: 129098, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-33515942

RESUMO

We report the modular design and synthesis of an amine dangled Schiff base quinoline-morpholine conjugate (QMC) for highly selective detection of Pb2+ ions via fluorimetry. The sensing strategy of QMC towards Pb2+ ion exhibits a large blue shift with fluorescent enhancement via the intramolecular charge transfer (ICT) process. At the same time, QMC coordination with Pb2+, the CN single bond rotation between quinoline and morpholine rings and the CN isomerization process were blocked. Best of our knowledge, this is the first blue shifted turn-on fluorescent chemosensor for Pb2+ ion via the ICT process. Furthermore, QMC selectively detects Pb2+ ion without any interference with alkali, alkaline earth, and transition metal ions, and limit of detection (LOD) downs to 13 µM, which is a permissible level of Pb2+ ion in drinking water reported by WHO. The 1:2 binding stoichiometry between QMC and Pb2+ was confirmed by fluorimetric, 1H NMR titration, mass spectrometry, and theoretical studies. Finally, QMC was potentially applied for the sensing of Pb2+ ions in milk, red wine, live cells and an INHIBIT molecular logic function was constructed by using Pb2+ and EDTA as chemical inputs.


Assuntos
Corantes Fluorescentes/química , Lógica , Leite/química , Imagem Molecular/métodos , Quinolinas/química , Animais , Chumbo/análise , Chumbo/química , Limite de Detecção , Bases de Schiff/química , Espectrometria de Fluorescência
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 246: 119018, 2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33096446

RESUMO

A simple hydroxyl-substituted triphenyl-imidazole based receptor (HTPI) which selectively detects Cu2+ ion by colorimetric and fluorimetric methods was developed. HTPI detects the Cu2+ ions with the absorption enhancement and fluorescence quenching by the possible ligand to metal charge transfer (LMCT) and the chelation-enhanced quenching (CHEQ) approaches, respectively. HTPI showed high selectivity and sensitivity for Cu2+ ions detection over other interfering and competing metal ions. Interestingly, HTPI detects Cu2+ ion (LOD) at nanomolar concentrations (19 × 10-9 M (UV-vis) & 27 × 10-9 M (fluorescence), respectively), which is lower than the permissible level of Cu2+ ion reported by World Health Organization (WHO). Furthermore, HTPI was applied to the molecular logic gate function by using chemical inputs, and Cu2+ ion was potentially removed (95%) via Capacitive Deionization technique.

10.
Anal Chim Acta ; 1090: 114-124, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31655636

RESUMO

Pyrene-phenylglycinol tangled ratiometric sensor (R)-1 was developed for the detection of Al3+ ion over other metal ions. Ratiometric behaviour of (R)-1 for Al3+ ion explained through monomer emission and excimer quenching leads to avoiding the π-π interactions of bis-pyrene rings. Pull-push to push-pull binding mechanism is successfully explained by DFT and sensing of Al3+-ions demonstrated in living cells. The LOD of (R)-1 for Al3+ downs to nanomolar concentrations which is lower than the allowed concentration of drinking water set by the (World Health Organization) WHO.


Assuntos
Alumínio/análise , Etanolaminas/química , Corantes Fluorescentes/química , Pirenos/química , Linhagem Celular , Etanolaminas/síntese química , Etanolaminas/toxicidade , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Humanos , Microscopia de Fluorescência/métodos , Pirenos/síntese química , Pirenos/toxicidade , Espectrometria de Fluorescência/métodos
11.
J Dev Orig Health Dis ; 9(3): 281-286, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29331157

RESUMO

Placental structure and function determine birth outcomes. Placental mass does not always correlate with fetal birth weight (BW) in uncomplicated pregnancies which raises the possibility of other variables such as placental shape and cord insertion being the determinants of placental efficiency. In total, 160 women with singleton pregnancy, recruited into a pregnancy cohort were studied. Placental weight (PW) was measured and other data were obtained from clinical records. Birth outcomes were classified as small for gestational age (SGA) and appropriate for gestational age (AGA) based on fetal gender, gestational age (GA) and BW. High-resolution images of the chorionic plate were recorded. The shape of the placenta and the insertion of the cord were measured using eccentricity index (EI) and cord centrality index (CCI). Only placentae with eccentrically inserted cords (n=136) were included. The mean BW and PW were 2942 (±435) g and 414 (±82) g with average GA of 38.6 weeks. The mean CCI and EI was 0.483 (±0.17) and 0.482 (±0.16). Neither of these correlated with placental efficiency. However, EI showed negative correlation with placental surface area and breadth. Upon sub-grouping the cohort into SGA (n=32) and AGA (n=104), the SGA babies with the highest EI (third tertile) had significantly lower BW than those with the least eccentric placentae (first tertile). Although eccentric-shaped placentae were present in both SGA and AGA groups, the effect on BW was observed only in the SGA group.


Assuntos
Peso ao Nascer , Retardo do Crescimento Fetal/etiologia , Recém-Nascido Pequeno para a Idade Gestacional , Doenças Placentárias/fisiopatologia , Adulto , Feminino , Peso Fetal , Idade Gestacional , Humanos , Recém-Nascido , Masculino , Gravidez , Estudos Retrospectivos , Adulto Jovem
12.
Indian J Endocrinol Metab ; 22(6): 770-773, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30766816

RESUMO

BACKGROUND: Circulating microRNA (miRNA/miR) levels are emerging out as markers of tissue level changes; however, their role in type 2 diabetes (T2D) needs to be explored. The study aimed to compare the circulating levels of the miRNA (miR9, miR30d, miR1, miR133a, miR29a, miR143) between T2D and gender matched controls and also to evaluate the strength of association between circulating miRNAs and beta cell function/insulin resistance among Indians with T2D. SUBJECTS AND METHODS: Thirty T2D (25-60 years) and their gender matched controls (n = 30) were recruited. Plasma glucose and insulin, HbA1c, lipid profile, and miRNA levels were estimated. Insulin resistance and beta cell function (HOMA IR and %B) were derived. Body composition was assessed by Dual-energy-x-ray absorptiometry (DXA). Comparison between the study groups was performed using independent "t" test and strength of association by Pearson's correlation. RESULTS: There was a significant difference in HOMA IR (P = 0.03) and %B (P = 0.001) between the two study groups. The muscle mass, percent body fat, and muscle to fat ratio were comparable between the two study groups. miRNA 30d was significantly higher in the T2D compared to control group even after controlling for age (P = 0.005). There was a significant positive association between miR30d with HOMA-IR (r = 0.26, P = 0.04). CONCLUSION: The current study demonstrated that miR30d (insulin gene transcription in pancreatic beta cell and regulator of insulin sensitivity in skeletal muscle) was overexpressed among T2D. Further role of other miRNA and their interaction in regulation of beta cell function and insulin resistance needs to be studied.

13.
Artigo em Inglês | MEDLINE | ID: mdl-27888783

RESUMO

A simple chalcone based dual analyte fluorescent probe FPC for Al3+ and HSO3- ions was developed. FPC detects both the analytes through a "turn off-on" approach and by the PET and ICT mechanism. FPC showed high selectivity and sensitivity for Al3+ and HSO3- ions detection over other interfering and competing metal ions. In addition, the LOD of FPC for sensing Al3+ and HSO3- ions was found to be 1.60×10-7M and 0.17×10-6M respectively. An electrochemical desalination technique was employed for the complete removal of Al3+ ions from the environmental water samples by using the probe FPC.

14.
Artigo em Inglês | MEDLINE | ID: mdl-25744532

RESUMO

A simple anthracene based chalcone as a fluorescent chemosensor 1, capable of detecting Pb(2+) in aqueous media, has been synthesized by the reaction between pyridine 2-carboxaldehyde and 9-acetyl anthracene. The Pb(2+) recognition processes follows a photo induced electron transfer (PET) mechanism and are scarcely influenced by other coexisting metal ions. In addition, determination of lead in a variety of samples was also determined.


Assuntos
Antracenos/química , Chalcona/química , Corantes Fluorescentes/química , Chumbo/análise , Concentração de Íons de Hidrogênio , Cinética , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Fatores de Tempo , Poluentes Químicos da Água/análise
17.
Conf Proc IEEE Eng Med Biol Soc ; 2006: 5206-9, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17946685

RESUMO

It has been observed in previous studies that the detection of stage I pressure ulcers becomes more difficult by unaided visual inspection and/or by using currently available techniques with darker skin subjects, due to increased melanin content. This difficulty is indicated by the elevated proportion of black and hispanic patients developing more serious stage III and IV pressure ulcers compared to white patients. The ultimate goal of this project, undertaken by MARC at the University of Virginia, is to develop a low-cost, non-contact imaging-based stage I pressure ulcer detection system for use by support staff in assisted living and skilled nursing facilities to increase the ulcer detection rate over a wide range of skin colors. This paper describes an image enhancement procedure that improves the detection of pressure ulcers when applied to the color images of ulcer sites. Preliminary results clearly indicate that the enhanced images exhibit higher contrast and make the pressure ulcer site more conspicuous to the examiner. The experiments show promising results even for subjects with black and dark brown skin colors.


Assuntos
Gráficos por Computador , Eritema/diagnóstico , Úlcera por Pressão/diagnóstico , Pele/patologia , Idoso , Algoritmos , Cor , Desenho de Equipamento , Eritema/patologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Casas de Saúde , Software
18.
J Bacteriol ; 181(23): 7192-8, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10572120

RESUMO

Physiological studies of a mutant of Escherichia coli lacking the three lytic transglycosylases Slt70, MltA, and MltB revealed that interference with murein turnover can prevent AmpC beta-lactamase induction. The triple mutant, although growing normally, shows a dramatically reduced rate of murein turnover. Despite the reduction in the formation of low-molecular-weight murein turnover products, neither the rate of murein synthesis nor the amount of murein per cell was increased. This might be explained by assuming that during growth in the absence of the major lytic transglycosylases native murein strands are excised by the action of endopeptidases and directly reused without further breakdown to muropeptides. The reduced rate of murein turnover could be correlated with lowered cefoxitin-induced expression of beta-lactamase, present on a plasmid carrying the ampC and ampR genes from Enterobacter cloacae. Overproduction of MltB stimulated beta-lactamase induction, whereas specific inhibition of Slt70 by bulgecin repressed ampC expression. Thus, specific inhibitors of lytic transglycosylases can increase the potency of penicillins and cephalosporins against bacteria inducing AmpC-like beta-lactamases.


Assuntos
Proteínas de Escherichia coli , Escherichia coli/enzimologia , Glicosídeo Hidrolases , Peptidoglicano/metabolismo , beta-Lactamases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Enterobacter cloacae/enzimologia , Ativação Enzimática/genética , Escherichia coli/crescimento & desenvolvimento , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Mutação , Fatores de Tempo , Resistência beta-Lactâmica/genética
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