scholarly journals Raman-Based Diagnostics of Stalk Rot Disease of Maize Caused by Colletotrichum graminicola

2021 ◽  
Vol 12 ◽  
Author(s):  
Charles Farber ◽  
John S. Bennett ◽  
Tianyi Dou ◽  
Yousef Abugalyon ◽  
Dillon Humpal ◽  
...  

Stalk rot caused by Colletotrichum graminicola is a disease of worldwide importance. Stalk rot is difficult to detect at the early stages of infection because the fungus colonizes the tissues inside the maize stem. Current diagnostic methods are time-consuming, laborious, and destructive to the stem tissue. We utilized Raman spectroscopy to follow the development of stalk rot in three different maize genotypes grown either in the field or the greenhouse. We then used the acquired spectra to calibrate statistical models to differentiate amongst the different disease timepoints and the genotypes themselves. This non-invasive spectroscopic method enabled high-accuracy identification of stalk rot based on both stalk and leaf spectra. We additionally found that leaf spectra were favorable for identifying maize by genotype. Finally, we identified Raman bands that showed correlation with the sizes of stalk rot-associated lesions in the stems. We demonstrated that Raman spectroscopy is a viable tool for detection of stalk rot disease, as well as potent for the differentiation of maize genotypes.

2002 ◽  
Vol 15 (2) ◽  
pp. 120-128 ◽  
Author(s):  
M. R. Thon ◽  
E. M. Nuckles ◽  
J. E. Takach ◽  
L. J. Vaillancourt

Colletotrichum graminicola causes anthracnose leaf blight and stalk rot of maize. We used restriction-enzyme mediated insertional (REMI) mutagenesis to identify a gene in this fungus that is required for pathogenicity to both stalks and leaves. The predicted polypeptide encoded by this gene, which we have named CPR1, is similar to a family of proteins that comprise one subunit of the eukaryotic micro-somal signal peptidase. The nonpathogenic CPR1 REMI mutant contains a plasmid integration in the 3′ untranslated region of the gene, 19 bp downstream from the stop codon. The result is a significant reduction in transcript levels in comparison to the wild type, perhaps as a result of increased transcript instability. We were unable to knock out the CPR1 gene, and it may be essential for viability. Microscopic examination of the REMI mutant on maize leaves revealed that it is fully capable of penetrating and colonizing host cells during the initial, biotrophic phases of the disease interaction but, unlike the wild type, it appears to be unable to switch to a necrotrophic mode of growth. We suggest that the CPR1 REMI mutant may be unable to secrete sufficient quantities of degradative enzymes to support that transition. The CPR1 REMI mutant provides us with a useful tool for future studies of the role of fungal protein transport in this important stalk rot disease of maize.


2021 ◽  
Vol 4 (1) ◽  
pp. 239-247
Author(s):  
Subash Subedi ◽  
Saraswati Neupane ◽  
Keshab Babu Koirala ◽  
Lokendra Oli

The inadequate source of resistance materials in maize against major biotic stresses is one of the main reasons for considerable loss of grain yield in Nepal. Post flowering stalk rot disease caused by Fusarium moniliforme is a serious disease that exposes high incidence at grain filling stage of maize in terai region of Nepal during summer season. This study was done to evaluate level of resistance, or tolerance in selected genotypes against the post flowering stalk rot disease of maize. Accordingly, thirty maize genotypes were tested for maize stalk rot resistance during summer season of 2016 and 2017 at National Maize Research Program, Rampur (NMRP), Chitwan. The experiment was done under natural epiphytotic condition at hot spot of the disease by using Randomized Complete Block design with 2 replications for each treatment. The package of practices was followed as per national recommendation. The summer season of 2016 and 2017 were affable for post flowering stalk rot of maize at NMRP, Rampur. Out of 30 genotypes, most of the tested entries showed susceptible reaction during both the years; however, RML-95/RML-96, Across-9942/Across-9944, ZM-401, Rampur 34, RamS03F08 and TLBRS07F16 showed resistant reaction against the disease and might be useful for the development of post flowering stalk rot resistant maize varieties for terai region of Nepal.


1995 ◽  
Vol 73 (04) ◽  
pp. 592-596 ◽  
Author(s):  
Sabina Villalta ◽  
Paolo Prandoni ◽  
Alberto Cogo ◽  
Paola Bagatella ◽  
Andrea Piccioli ◽  
...  

SummaryBackground. Despite the availability of several diagnostic methods for the detection of deep-vein thrombosis (DVT), the identification of previous episodes of DVT remains a diagnostic challenge.Study objective. To assess the reliability of a combination of a standardized clinical score with three non-invasive tests: compression ultrasonography (CUS), Doppler ultrasound (DUS), and photoplethysmography (PPG), in determining the presence or the absence of previous proximal DVT.Methods. One hundred consecutive unselected outpatients were identified, who had undergone contrast venography six to nine years previously because of the clinical suspicion of DVT (confirmed in 43). They were blindly reinvestigated by a panel of trained operators unaware of venography results. They underwent a clinical evaluation of the lower limb, by applying a standardized score to five symptoms and six signs (grading each item from 0 to 3); a PPG test to determine the venous refilling time; a DUS test to determine the venous reflux separately in the common femoral and the popliteal vein; and a CUS test to determine vein compressibility in the same regions.Results. An abnormal CUS test and/or the demonstration of venous reflux in the popliteal region and/or a high clinical score (≥ 8) identified twenty-four of the 43 (56%) DVT + patients with a specificity of 89%. The combination of normal CUS with the absence of venous reflux in both the common femoral and popliteal vein and a low clinical score excluded previous thrombosis in 45 (79%) of the 57 DVT- patients (negative predictive value, 78%). Abnormal venous reflux in the isolated common femoral vein did not reliably predict the presence or absence of previous DVT. However, this occurred in only 13 (13%) patients. The PPG determination of venous refilling time did not improve the results obtained with the other tests.Conclusions. The combination of a standardized clinical evaluation with the results of CUS and DUS can reliably diagnose or exclude previous proximal-vein thrombosis in almost 90% of patients with previous episodes of suspected DVT.


2020 ◽  
pp. 54-59
Author(s):  
A. S. Molostova ◽  
N. S. Gladyshev ◽  
A. V. Svarval ◽  
R. S. Ferman ◽  
A. B. Karasyova ◽  
...  

(HP) infection was performed using invasive and non-invasive methods. The study group consisted of 95 patients with dyspepsia. HP infection was detected in 47 patients (49.4 %). The expediency of using a set of diagnostic methods for detecting HP (PCR, immunochromatographic, bacteriological and method for determining urease activity) is proved. Most often (100 %) in patients HP infection was detected in biopsies using the PCR method. Somewhat less frequently it was detected when examining biopsies with an invasive biochemical method (AMA RUT Reader) (82 %) and fecal immunochromatographic method (83 %). Despite the fact that helicobacteriosis was detected bacteriologically in a small number of patients (24 %), this method is of particular value, since it allows you to assess the sensitivity to antimicrobial drugs and probiotics, and does not give false positive results.


2015 ◽  
Vol 24 (2) ◽  
pp. 197-201 ◽  
Author(s):  
Ramesh P. Arasaradnam ◽  
Michael McFarlane ◽  
Emma Daulton ◽  
Erik Westenbrink ◽  
Nicola O’Connell ◽  
...  

Background & Aims: Non-Alcoholic Fatty Liver Disease (NAFLD) is the commonest cause of chronic liver disease in the western world. Current diagnostic methods including Fibroscan have limitations, thus there is a need for more robust non-invasive screening methods. The gut microbiome is altered in several gastrointestinal and hepatic disorders resulting in altered, unique gut fermentation patterns, detectable by analysis of volatile organic compounds (VOCs) in urine, breath and faeces. We performed a proof of principle pilot study to determine if progressive fatty liver disease produced an altered urinary VOC pattern; specifically NAFLD and Non-Alcoholic Steatohepatitis (NASH).Methods: 34 patients were recruited: 8 NASH cirrhotics (NASH-C); 7 non-cirrhotic NASH; 4 NAFLD and 15 controls. Urine was collected and stored frozen. For assay, the samples were defrosted and aliquoted into vials, which were heated to 40±0.1°C and the headspace analyzed by FAIMS (Field Asymmetric Ion Mobility Spectroscopy). A previously used data processing pipeline employing a Random Forrest classification algorithm and using a 10 fold cross validation method was applied.Results: Urinary VOC results demonstrated sensitivity of 0.58 (0.33 - 0.88), but specificity of 0.93 (0.68 - 1.00) and an Area Under Curve (AUC) 0.73 (0.55 -0.90) to distinguish between liver disease and controls. However, NASH/NASH-C was separated from the NAFLD/controls with a sensitivity of 0.73 (0.45 - 0.92), specificity of 0.79 (0.54 - 0.94) and AUC of 0.79 (0.64 - 0.95), respectively.Conclusions: This pilot study suggests that urinary VOCs detection may offer the potential for early non-invasive characterisation of liver disease using 'smell prints' to distinguish between NASH and NAFLD.


2019 ◽  
Vol 19 (2) ◽  
pp. 105-111
Author(s):  
Nadia Shafei ◽  
Mohammad Saeed Hakhamaneshi ◽  
Massoud Houshmand ◽  
Siavash Gerayeshnejad ◽  
Fardin Fathi ◽  
...  

Background: Beta thalassemia is a common disorder with autosomal recessive inheritance. The most prenatal diagnostic methods are the invasive techniques that have the risk of miscarriage. Now the non-invasive methods will be gradually alternative for these invasive techniques. Objective: The aim of this study is to evaluate and compare the diagnostic value of two non-invasive diagnostic methods for fetal thalassemia using cell free fetal DNA (cff-DNA) and nucleated RBC (NRBC) in one sampling community. Methods: 10 ml of blood was taken in two k3EDTA tube from 32 pregnant women (mean of gestational age = 11 weeks), who themselves and their husbands had minor thalassemia. One tube was used to enrich NRBC and other was used for cff-DNA extraction. NRBCs were isolated by MACS method and immunohistochemistry; the genome of stained cells was amplified by multiple displacement amplification (MDA) procedure. These products were used as template in b-globin segments PCR. cff-DNA was extracted by THP method and 300 bp areas were recovered from the agarose gel as fetus DNA. These DNA were used as template in touch down PCR to amplify b-globin gen. The amplified b-globin segments were sequenced and the results compared with CVS resul. Results: The data showed that sensitivity and specificity of thalassemia diagnosis by NRBC were 100% and 92% respectively and sensitivity and specificity of thalassemia diagnosis by cff-DNA were 100% and 84% respectively. Conclusion: These methods with high sensitivity can be used as screening test but due to their lower specificity than CVS, they cannot be used as diagnostic test.


Author(s):  
Jian Liu ◽  
Yong Yu ◽  
Chenqi Zhu ◽  
Yu Zhang

The finite volume method (FVM)-based computational fluid dynamics (CFD) technology has been applied in the non-invasive diagnosis of coronary artery stenosis. Nonetheless, FVM is a time-consuming process. In addition to FVM, the lattice Boltzmann method (LBM) is used in fluid flow simulation. Unlike FVM solving the Navier–Stokes equations, LBM directly solves the simplified Boltzmann equation, thus saving computational time. In this study, 12 patients with left anterior descending (LAD) stenosis, diagnosed by CTA, are analysed using FVM and LBM. The velocities, pressures, and wall shear stress (WSS) predicted using FVM and LBM for each patient is compared. In particular, the ratio of the average and maximum speed at the stenotic part characterising the degree of stenosis is compared. Finally, the golden standard of LAD stenosis, invasive fractional flow reserve (FFR), is applied to justify the simulation results. Our results show that LBM and FVM are consistent in blood flow simulation. In the region with a high degree of stenosis, the local flow patterns in those two solvers are slightly different, resulting in minor differences in local WSS estimation and blood speed ratio estimation. Notably, these differences do not result in an inconsistent estimation. Comparison with invasive FFR shows that, in most cases, the non-invasive diagnosis is consistent with FFR measurements. However, in some cases, the non-invasive diagnosis either underestimates or overestimates the degree of stenosis. This deviation is caused by the difference between physiological and simulation conditions that remains the biggest challenge faced by all CFD-based non-invasive diagnostic methods.


2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Klara Retko ◽  
Maša Kavčič ◽  
Lea Legan ◽  
Polonca Ropret ◽  
Bojana Rogelj Škafar ◽  
...  

AbstractIn this study, a painted beehive panel from the collection of the Slovene Ethnographic Museum was examined with respect to its material composition with the aim to reveal the painting technique. Due to the state of degradation due to outdoor weathering (UV irradiation, rainfall, extreme temperature and humidity fluctuations), as well as past conservation interventions, the object represented a complex analytical challenge. We aimed for non-invasive techniques (FTIR in reflection mode, Raman spectroscopy and hyperspectral imaging in the range of 400–2500 nm); however, in order to explore paint layers, cross-sections were also analysed using Raman spectroscopy. FTIR spectroscopy in transmission mode and gas chromatography coupled to mass spectrometry were also used on sample fragments. Various original materials were identified such as pigments and binders. The surface coating applied during conservation interventions was also characterised. Additionally, organic compounds were found (oxalate, carboxylate), representing transformation products. The potential use of Prussian blue as a background paint layer is discussed.


Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1922
Author(s):  
Gwang Su Kim ◽  
Yumin Park ◽  
Joonchul Shin ◽  
Young Geun Song ◽  
Chong-Yun Kang

The breath gas analysis through gas phase chemical analysis draws attention in terms of non-invasive and real time monitoring. The array-type sensors are one of the diagnostic methods with high sensitivity and selectivity towards the target gases. Herein, we presented a 2 × 4 sensor array with a micro-heater and ceramic chip. The device is designed in a small size for portability, including the internal eight-channel sensor array. In2O3 NRs and WO3 NRs manufactured through the E-beam evaporator’s glancing angle method were used as sensing materials. Pt, Pd, and Au metal catalysts were decorated for each channel to enhance functionality. The sensor array was measured for the exhaled gas biomarkers CH3COCH3, NO2, and H2S to confirm the respiratory diagnostic performance. Through this operation, the theoretical detection limit was calculated as 1.48 ppb for CH3COCH3, 1.9 ppt for NO2, and 2.47 ppb for H2S. This excellent detection performance indicates that our sensor array detected the CH3COCH3, NO2, and H2S as biomarkers, applying to the breath gas analysis. Our results showed the high potential of the gas sensor array as a non-invasive diagnostic tool that enables real-time monitoring.


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