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1.
J Oleo Sci ; 73(4): 467-477, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38556281

RESUMO

Rice bran (RB) and rice bran oil (RBO) are exploring as prominent food component worldwide and their compositional variation is being varied among the world due to regional and production process. In this study, Fermented Rice Bran (FRB) was produced by employing edible gram-positive bacteria (Lactobacillus acidophilus, Lactobacillus bulgaricus and Bifidobacterium bifidum) at 125×10 5 spore g -1 of rice bran, and investigated to evaluate nutritional quality. The Crude Rice Bran Oil (CRBO) was extracted from RB and its quality was also investigated compared to market available rice bran oil (MRBO) in Bangladesh. We found that fermentation of rice bran with lactic acid bacteria increased total proteins (29.52%), fat (5.38%), ash (48.47%), crude fiber (38.96%), and moisture (61.04%) and reduced the carbohydrate content (36.61%). We also found that essential amino acids (Threonine, valine, leucine, lysine, histidine and phenylalanine) and non-essential amino acids (alanine, aspartate, glycine, glutamine, serine and tyrosine) were increased in FRB except methionine and proline. Moreover, total phenolic content, tannin content, flavonoid content and antioxidant activity were increased in FRB. The RBO analysis showed that γ-oryzanol content (10.00 mg/g) were found in CRBO compared to MRBO (ranging 7.40 to 12.70 mg/g) and Vitamin-E content 0.20% were found higher in CRBO compared to MRBO (ranging 0.097 to 0.12%). The total saturated (25.16%) and total unsaturated fatty acids (74.44%) were found in CRBO whereas MRBO contained total saturated (22.08 to 24.13%) and total unsaturated fatty acids (71.91 to 83.29%) respectively. The physiochemical parameters (density, refractive index, iodine value) were found satisfactory in all sample except acid value and peroxide value higher in CRBO. Heavy metal concentration was found within an acceptable range in both CRBO and MRBO. Thus FRB and RBO could be value added food supplement for human health.


Assuntos
Antioxidantes , Ácidos Graxos Insaturados , Humanos , Óleo de Farelo de Arroz/química , Ácidos Graxos Insaturados/análise , Antioxidantes/análise , Vitamina E , Fenóis
2.
Heliyon ; 10(4): e25544, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38384561

RESUMO

In Bangladesh, the annual production of rubber seeds is typically left untapped although the seeds contained a high percentage of oil but underutilized without any value-added utilization. This study aims to evaluate the geographical effect on physicochemical properties, fatty acid composition and the antimicrobial activity of oil extracted from rubber seeds. Seeds were collected from three different regions of Bangladesh and the oil was extracted by the soxhlet method using n-hexane as a solvent. Results demonstrated that the geographical regions have some significant effect on the properties of rubber seed oil (RSO). The physicochemical properties of RSO varied from region to region. For example, the percent of yield, higher heating value, and flash point varied from 50.0 to 50.8 %, 31.8-33.3 kJ/g, and 237-245 °C, respectively. The chemical parameters, such as acid value, iodine value, and hydroxyl value varied from 13.3 to 18.2 mg KOH/g, 132-137 g I2/100g, and 47.7-55.8 mg KOH/g, respectively. Chromatographic analysis showed that RSO mainly contains palmitic, linoleic, linolenic, and stearic acid. Regional variations were also seen in the composition of these fatty acids. Most notably, regardless of the rubber seeds collected from various locations, RSO exhibited inhibitory activity against only gram positive bacteria. The zone of inhibition range for different tested gram positive bacteria was 2.33-11.17 mm irrespective of different RSO samples.

3.
Artigo em Inglês | MEDLINE | ID: mdl-37993011

RESUMO

Waterborne cadmium (Cd) accumulates in the fish intestine and causes irreversible toxicity by disrupting intestinal immunity and microbial diversity. To explore the toxicity of environmentally available high Cd concentration on intestinal immunity and microbial diversity of fish, we selected the widely used bioindicator model species, Common carp (Cyprinus carpio). Literature review and Cd pollution data supported sequential doses of 0.2, 0.4, 0.8, 1.6, 3.2, and 6.4 mg/L Cd for 30 days. Based on intestinal tissue Cd accumulation, previous studies, and environmentally available Cd data, 0.4 and 1.6 mg/L Cd were selected for further studies. Intestinal Cd bioaccumulation increased significantly to ~100 times in fish exposed to 1.6 mg/L Cd. We observed villous atrophy, increased goblet cells with mucus production, muscularis erosion, and thickened lamina propria due to intense inflammatory cell infiltration in the intestine at this Cd concentration. Cd-induced immunosuppression occurred with increased lysozyme, alkaline phosphate (AKP), and acid phosphate (ACP). High levels of catalase (CAT), total antioxidant capacity (T-AOC), malondialdehyde (MDA), and hydrogen peroxide (H2O2) suggested induced oxidative stress and poor metabolism by α-amylase and lipase suppression for Cd toxicity. Proteobacteria (41.2 %), Firmicutes (21.8 %), and Bacteroidetes (17.5 %) were the dominant bacterial phyla in the common carp intestine. Additionally, potential pathogenic Cyanobacteria increased in Cd-treated fish. The decrease of beneficiary bacteria like Aeromonas, and Cetobacterium indicated Cd toxicity. Overall, these findings indicate harmful consequences of high Cd concentration in the intestinal homeostasis and health status of fish.


Assuntos
Carpas , Animais , Carpas/metabolismo , Cádmio/toxicidade , Cádmio/metabolismo , Peróxido de Hidrogênio , Bactérias/metabolismo , Intestinos/microbiologia , Fosfatos
4.
Clin Case Rep ; 11(2): e6926, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36789296

RESUMO

Atypical presentations may be presented with the common symptoms in Dengue. We, hereby, present a case of Dengue who was admitted in our hospital with the complaints of fever, upper abdominal pain, and vomiting, literally diagnosed as a case of acute pancreatitis.

5.
Heliyon ; 8(10): e10838, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36247118

RESUMO

Cabbage, cauliflower and broccoli are well-known vegetables from the Brassica family having functional effects on human health. This study was carried out to identify different antioxidant properties and to quantify phenolic compounds by HPLC-DAD in different extracts (methanol, ethanol and water: acetic acid: acetone) of these vegetables. The results showed that, the methanolic dry extract of cabbage possessed the highest antioxidant activity (549 ± 7.30 µg/g) and IC50 was 90 ± 2.52 µg/mL than others. Whereas the ethanolic dry extract of cauliflower had 348 ± 5.20 µg/g of flavonoid, which was the highest among all. The maximum levels of total tannin (414 ± 5.20 µg/g) and total phenolic content (465 ± 3.25 µg/g) was found in broccoli dry extract. Several polyphenolic compounds were identified in different extracts of the vegetables and they were Cauliflower (8) > Cabbage (10) > Broccoli (9) in total. Therefore, the use of total vegetables rather than extracts in the food industry would be more appropriate to get greater health benefit.

6.
Analyst ; 147(8): 1589-1597, 2022 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-35293399

RESUMO

For conception, sperm cells travel towards the oocyte. This journey is accomplished by only a few sperm cells, following various guidance mechanisms. Of these mechanisms, rheotaxis plays a significant role in guiding the sperm over a long distance. By taking advantage of this natural rheotaxis behavior of sperm, we have developed a microfluidic chip that isolates healthy sperm cells. The developed chip consists of different chambers separated by microchannels that facilitate separation of motile sperm cells from unprocessed semen samples with the help of fluid flow. The sperm cells are subjected to different velocities in different parts of the chip that direct functional sperm towards the collection chamber utilizing positive rheotaxis. The results from the developed microfluidic chip (with 0.5 µL min-1 flow rate) have shown almost 100% motility, a significantly higher percentage of morphologically normal sperm cells with lesser sperm DNA fragmentation than the control (no-flow) and raw semen sample. This chip satisfies the need of a clinical setting as it is low-cost, easy to operate and uses a small semen volume for sperm sorting.


Assuntos
Dispositivos Lab-On-A-Chip , Motilidade dos Espermatozoides , Animais , Fragmentação do DNA , Masculino , Análise do Sêmen , Espermatozoides
7.
J Biophotonics ; 15(4): e202100310, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34936215

RESUMO

Identification of cell death mechanisms, particularly distinguishing between apoptotic versus nonapoptotic pathways, is of paramount importance for a wide range of applications related to cell signaling, interaction with pathogens, therapeutic processes, drug discovery, drug resistance, and even pathogenesis of diseases like cancers and neurogenerative disease among others. Here, we present a novel high-throughput method of identifying apoptotic versus necrotic versus other nonapoptotic cell death processes, based on lensless digital holography. This method relies on identification of the temporal changes in the morphological features of mammalian cells, which are unique to each cell death processes. Different cell death processes were induced by known cytotoxic agents. A deep learning-based approach was used to automatically classify the cell death mechanism (apoptotic vs necrotic vs nonapoptotic) with more than 93% accuracy. This label free approach can provide a low cost (<$250) alternative to some of the currently available high content imaging-based screening tools.


Assuntos
Holografia , Neoplasias , Animais , Morte Celular , Mamíferos , Microscopia , Necrose , Neoplasias/tratamento farmacológico
8.
Science ; 375(6577): eabi9069, 2022 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-34855513

RESUMO

We conducted a cluster-randomized trial to measure the effect of community-level mask distribution and promotion on symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in rural Bangladesh from November 2020 to April 2021 (N = 600 villages, N = 342,183 adults). We cross-randomized mask type (cloth versus surgical) and promotion strategies at the village and household level. Proper mask-wearing increased from 13.3% in the control group to 42.3% in the intervention arm (adjusted percentage point difference = 0.29; 95% confidence interval = [0.26, 0.31]). The intervention reduced symptomatic seroprevalence (adjusted prevalence ratio = 0.91 [0.82, 1.00]), especially among adults ≥60 years old in villages where surgical masks were distributed (adjusted prevalence ratio = 0.65 [0.45, 0.85]). Mask distribution with promotion was a scalable and effective method to reduce symptomatic SARS-CoV-2 infections.


Assuntos
COVID-19/prevenção & controle , Controle de Doenças Transmissíveis , Promoção da Saúde , Máscaras , Fatores Etários , Bangladesh/epidemiologia , COVID-19/epidemiologia , Análise por Conglomerados , Feminino , Humanos , Masculino , Distanciamento Físico , Saúde Pública , População Rural , Estudos Soroepidemiológicos , Fatores Sexuais
9.
Infect Dis Rep ; 13(2): 518-539, 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199547

RESUMO

Herpes is a widespread viral infection caused by the herpes simplex virus (HSV) that has no permanent cure to date. There are two subtypes, HSV-1 and HSV-2, that are known to cause a variety of symptoms, ranging from acute to chronic. HSV is highly contagious and can be transmitted via any type of physical contact. Additionally, viral shedding can also happen from asymptomatic infections. Thus, early and accurate detection of HSV is needed to prevent the transmission of this infection. Herpes can be diagnosed in two ways, by either detecting the presence of the virus in lesions or the antibodies in the blood. Different detection techniques are available based on both laboratory and point of care (POC) devices. Laboratory techniques include different biochemical assays, microscopy, and nucleic acid amplification. In contrast, POC techniques include microfluidics-based tests that enable on-spot testing. Here, we aim to review the different diagnostic techniques, both laboratory-based and POC, their limits of detection, sensitivity, and specificity, as well as their advantages and disadvantages.

10.
Biosensors (Basel) ; 11(7)2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34201849

RESUMO

The dengue virus (DENV) is a vector-borne flavivirus that infects around 390 million individuals each year with 2.5 billion being in danger. Having access to testing is paramount in preventing future infections and receiving adequate treatment. Currently, there are numerous conventional methods for DENV testing, such as NS1 based antigen testing, IgM/IgG antibody testing, and Polymerase Chain Reaction (PCR). In addition, novel methods are emerging that can cut both cost and time. Such methods can be effective in rural and low-income areas throughout the world. In this paper, we discuss the structural evolution of the virus followed by a comprehensive review of current dengue detection strategies and methods that are being developed or commercialized. We also discuss the state of art biosensing technologies, evaluated their performance and outline strategies to address challenges posed by the disease. Further, we outline future guidelines for the improved usage of diagnostic tools during recurrence or future outbreaks of DENV.


Assuntos
Dengue/diagnóstico , Sistemas Automatizados de Assistência Junto ao Leito , Anticorpos Antivirais , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulina G , Sensibilidade e Especificidade
11.
Microbes Infect ; 23(4-5): 104832, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33872807

RESUMO

COVID-19, a highly transmissible pandemic disease, is affecting millions of lives around the world. Severely infected patients show acute respiratory distress symptoms. Sustainable management strategies are required to save lives of the infected people and further preventing spread of the virus. Diagnosis, treatment, and vaccination development initiatives are already exhibited from the scientific community to fight against this virus. In this review, we primarily discuss the management strategies including prevention of spread, prophylaxis, vaccinations, and treatment for COVID-19. Further, analysis of vaccine development status and performance are also briefly discussed. Global socioeconomic impact of COVID-19 is also analyzed as part of this review.


Assuntos
COVID-19/prevenção & controle , COVID-19/terapia , Antivirais/uso terapêutico , Vacinas contra COVID-19/administração & dosagem , Controle de Doenças Transmissíveis , Genoma Viral , Humanos , Pandemias/economia , SARS-CoV-2/genética , Vacinação
12.
Expert Rev Mol Diagn ; 21(3): 269-288, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33621145

RESUMO

Introduction: Coronavirus disease 2019 (COVID-19), a respiratory illness caused by novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), had its first detection in December 2019 in Wuhan (China) and spread across the world. In March 2020, the World Health Organization (WHO) declared COVID-19 a pandemic disease. The utilization of prompt and accurate molecular diagnosis of SARS-CoV-2 virus, isolating the infected patients, and treating them are the keys to managing this unprecedented pandemic. International travel acted as a catalyst for the widespread transmission of the virus.Areas covered: This review discusses phenotype, structural, and molecular evolution of recognition elements and primers, its detection in the laboratory, and at point of care. Further, market analysis of commercial products and their performance are also evaluated, providing new ways to confront the ongoing global public health emergency.Expert commentary: The outbreak for COVID-19 created mammoth chaos in the healthcare sector, and still, day by day, new epicenters for the outbreak are being reported. Emphasis should be placed on developing more effective, rapid, and early diagnostic devices. The testing laboratories should invest more in clinically relevant multiplexed and scalable detection tools to fight against a pandemic like this where massive demand for testing exists.


Assuntos
COVID-19/diagnóstico , COVID-19/virologia , SARS-CoV-2/fisiologia , Biomarcadores , COVID-19/epidemiologia , COVID-19/transmissão , Gerenciamento Clínico , Evolução Molecular , Humanos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/normas , Técnicas de Amplificação de Ácido Nucleico , Pandemias , Testes Imediatos , RNA Viral
13.
F S Sci ; 2(4): 376-382, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-35559860

RESUMO

OBJECTIVE: To investigate whether the presented rheotaxis-based microfluidic device could be used to separate spermatozoa from viruses (i.e., Zika) in the infected semen sample during the selection and washing process. DESIGN: Quantitative and experimental study of the sperm washing/selection process through the microfluidic platform exploiting the positive rheotaxis of sperm. SETTING: None. PATIENT(S): None. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Human sperm were purchased from a sperm bank. The raw semen sample was mixed with viruses and loaded into a microfluidic device. Experiments were performed with 2 different flow rates (0 and 25 µL/minute) to investigate the washing efficiency of the device in the sperm selection process. The sperm sample was collected after 45 minutes and analyzed to check whether the collected sample is free of any infections (viruses) after isolation. RESULT(S): Fluorescent microscopy and quantitative polymerase chain reaction-based analysis showed that the sperm selected with the presented rheotaxis-based microfluidic device at the optimal flow rate (25 µL/minute) was free of any viruses. CONCLUSION(S): We have developed a simple, cost-effective microfluidic device that mimics the conditions of the female genital tract while washing out the raw semen efficiently during the selection process for assisted reproductive technology.


Assuntos
Vírus não Classificados , Infecção por Zika virus , Zika virus , Vírus de DNA , Feminino , Humanos , Dispositivos Lab-On-A-Chip , Masculino , Análise do Sêmen , Motilidade dos Espermatozoides , Espermatozoides
14.
Arch Pathol Lab Med ; 144(11): 1335-1343, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32886758

RESUMO

CONTEXT.­: Zika virus (ZIKV) infection, primarily transmitted by mosquitoes, causes various neurologic disorders. To differentiate ZIKV from other arboviruses, such as dengue, chikungunya, and yellow fever viruses, a highly specific, sensitive, and automated detection system is needed for point-of-care (POC) settings. OBJECTIVE.­: To detect ZIKV at POC settings, we have developed a fully automated lab-on-a-chip microfluidic platform for rapid disease detection by using reverse transcription loop-mediated isothermal amplification. DESIGN.­: The developed setup consists of a microfluidic chip, a platform for magnetic actuation, and a heater along with the sensor to precisely control the temperature for the target amplification. The platform accurately controls the movement of the magnetic beads that enable the isolation and purification of the target nucleotides adhered to their surface for the amplification and disease detection on the microfluidic chip. RESULTS.­: Within 40 minutes, change in color due to the presence of ZIKV amplicons was visually observed with the spiked plasma samples in the end point analysis. Also, we have accurately and specifically identified ZIKV in a small number of de-identified clinical samples. CONCLUSIONS.­: All-inclusive, the developed fully automated POC ZIKV diagnostic chip is rapid, simple, easy to use, inexpensive, and suitable for the areas where facilities are limited.


Assuntos
Dispositivos Lab-On-A-Chip/normas , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Testes Imediatos/normas , Infecção por Zika virus/diagnóstico , Zika virus/genética , Animais , Humanos , Dispositivos Lab-On-A-Chip/estatística & dados numéricos , Dispositivos Lab-On-A-Chip/virologia , Sistemas Automatizados de Assistência Junto ao Leito , Testes Imediatos/estatística & dados numéricos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Zika virus/fisiologia , Infecção por Zika virus/virologia
15.
Sci Rep ; 10(1): 11906, 2020 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-32681135

RESUMO

Zika virus (ZIKV) is an emerging flavivirus transmitted to humans by Aedes mosquitos. ZIKV can be transmitted from mother to fetus during pregnancy and can cause microcephaly and other birth defects. Effective vaccines for Zika are yet to be approved. Detection of the ZIKV is based on serological testing that often shows cross-reactivity with the Dengue virus (DENV) and other flaviviruses. We aimed to assemble a highly specific anti-Zika antibody panel to be utilized in the development of a highly specific and cost-effective ZIKV rapid quantification assay for viral load monitoring at point-of-care settings. To this end, we tested the affinity and specificity of twenty one commercially available monoclonal and polyclonal antibodies against ZIKV and DENV envelope proteins utilizing nine ZIKV and twelve DENV strains. We finalized and tested a panel of five antibodies for the specific detection and differentiation of ZIKV and DENV infected samples.


Assuntos
Anticorpos Antivirais/imunologia , Zika virus/imunologia , Zika virus/isolamento & purificação , Animais , Especificidade de Anticorpos/imunologia , Chlorocebus aethiops , Reações Cruzadas/imunologia , Vírus da Dengue/imunologia , Vírus da Dengue/isolamento & purificação , Limite de Detecção , Camundongos , Coelhos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Células Vero , Proteínas do Envelope Viral/imunologia
16.
Crit Rev Biotechnol ; 40(5): 623-638, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32308063

RESUMO

Although highly active antiretroviral therapy (HAART) has been introduced over twenty years ago to treat Human Immunodeficiency Virus (HIV) positive patients, acquired immunodeficiency syndrome (AIDS) is still one of the deadliest diseases found worldwide. AIDS prevalence and mortality rates are usually more pronounced in resource-constrained countries than in the developed world. The lack of trained medical technicians, sophisticated diagnostic equipment, and the overall scarcity of medical infrastructures have severely impacted HIV/AIDS diagnostics, which hinders the initiation and periodic monitoring of antiretroviral therapy (ART). Currently, available HIV viral load assays are not well-suited for resource-limited settings due to their high cost and a requirement for medical/technical infrastructures. In this paper, we review current and emerging diagnostic assays for HIV detection, with a focus on point-of-care (POC) based immunoassays for viral load measurement, drug resistance, and HIV recurrence. We also discuss the limitations of the available HIV assays and highlight the technological advancements in cellphone, paper, and flexible material-based assays which have the potential to improve HIV diagnosis and monitoring, thus assisting with the management of the disease.


Assuntos
Técnicas de Laboratório Clínico/métodos , Infecções por HIV/diagnóstico , Infecções por HIV/tratamento farmacológico , Fármacos Anti-HIV/uso terapêutico , Farmacorresistência Viral , Infecções por HIV/virologia , HIV-1/isolamento & purificação , Humanos , Sistemas Automatizados de Assistência Junto ao Leito , Carga Viral , Latência Viral
17.
Diagnostics (Basel) ; 10(1)2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31947549

RESUMO

The Zika virus (ZIKV) is an emerging flavivirus transmitted to humans by Aedes mosquitoes that can potentially cause microcephaly, Guillain-Barré Syndrome, and other birth defects. Effective vaccines for Zika have not yet been developed. There is a necessity to establish an easily deployable, high-throughput, low-cost, and disposable point-of-care (POC) diagnostic platform for ZIKV infections. We report here an automated magnetic actuation platform suitable for a POC microfluidic sandwich enzyme-linked immunosorbent assay (ELISA) using antibody-coated superparamagnetic beads. The smartphone integrated immunoassay is developed for colorimetric detection of ZIKV nonstructural protein 1 (NS1) antigen using disposable chips to accommodate the reactions inside the chip in microliter volumes. An in-house-built magnetic actuator platform automatically moves the magnetic beads through different aqueous phases. The assay requires a total of 9 min to automatically control the post-capture washing, horseradish peroxidase (HRP) conjugated secondary antibody probing, washing again, and, finally, color development. By measuring the saturation intensity of the developed color from the smartphone captured video, the presented assay provides high sensitivity with a detection limit of 62.5 ng/mL in whole plasma. These results advocate a great promise that the platform would be useful for the POC diagnosis of Zika virus infection in patients and can be used in resource-limited settings.

18.
RSC Adv ; 9(15): 8159-8168, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31777654

RESUMO

There is a need to create an easily deployable and point-of-care (POC) diagnostic platform for disease outbreaks and for monitoring and maintenance of chronic illnesses. Such platforms are useful in regions where access to clinical laboratories may be limited or constrained using cost-effective solutions to quickly process high numbers of samples. Using oil and water liquid-liquid interphase separation, immunoassays developed for microfluidic chips can potentially meet this need when leveraged with electromagnetic actuation and antibody-coated superparamagnetic beads. We have developed a microfluidic immunoassay detection platform, which enables assay automation and maintains successful liquid containment for future use in the field. The assay was studied through a series of magnetic and fluid simulations to demonstrate these optimizations, and an optimized chip was tested using a target model for HIV-1, the p24 capsid antigen. The use of minimal reagents further lowers the cost of each assay and lowers the required sample volume for testing (<50 µL), that can offer easy turnaround for sample collection and assay results. The developed microfluidic immunoassay platform can be easily scaled for multiplex or multi-panel specific testing at the POC.

19.
Sens Actuators B Chem ; 282: 225-231, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30828133

RESUMO

Point-of-care (POC) tests often rely on smartphone image methods for colorimetric analysis, but the results of such methods are frequently difficult to reproduce or standardize. The problem is aggravated by unpredictable image capture conditions, which pose a significant challenge when low limits of detection (LOD) are needed. Application-specific smartphone attachments are often used to standardize imaging conditions, but there has recently been an interest in equipment-free POC colorimetric analysis. Improved output metrics and preprocessing methods have been developed, but equipment-free imaging often has a high LOD and is inappropriate for quantitative tasks. Additional work is necessary to replace external smartphone attachments with algorithms. Towards this end, we have developed a video processing method that synthesizes many images into a single output metric. We use image features to select the best inputs from a large set of video frames and demonstrate that the resulting output values have a stronger correlation with laboratory methods and a lower standard error. The developed algorithm only requires 20 seconds of video and can easily be integrated with existing processing methods. We apply our algorithm to the NS1-based sandwich ELISA for Zika detection and show that the LOD is two times lower when our video-based method is used.

20.
J Exp Bot ; 70(5): 1683-1696, 2019 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-30715410

RESUMO

Feeding of sucking insects, such as the rice brown planthopper (Nilaparvata lugens; BPH), causes only limited mechanical damage on plants that is otherwise essential for injury-triggered defense responses against herbivores. In pursuit of complementary BPH elicitors perceived by plants, we examined the potential effects of BPH honeydew secretions on the BPH monocot host, rice (Oryza sativa). We found that BPH honeydew strongly elicits direct and putative indirect defenses in rice, namely accumulation of phytoalexins in the leaves, and release of volatile organic compounds from the leaves that serve to attract natural enemies of herbivores, respectively. We then examined the elicitor active components in the honeydew and found that bacteria in the secretions are responsible for the activation of plant defense. Corroborating the importance of honeydew-associated microbiota for induced plant resistance, BPHs partially devoid of their microbiota via prolonged antibiotics ingestion induced significantly less defense in rice relative to antibiotic-free insects applied to similar groups of plants. Our data suggest that rice plants may additionally perceive herbivores via their honeydew-associated microbes, allowing them to discriminate between incompatible herbivores-that do not produce honeydew-and those that are compatible and therefore dangerous.


Assuntos
Cucumis melo/microbiologia , Regulação da Expressão Gênica de Plantas/imunologia , Hemípteros/fisiologia , Herbivoria , Oryza/imunologia , Doenças das Plantas/imunologia , Animais
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