Search

Ticks are ectoparasites that cause dermatologic reactions directly by their bites and indirectly as vectors of bacterial, protozoal and viral diseases. Consequences vary from minor local reactions to significant systemic sequelae and are therefore of clinical relevance to dermatologists. In this article, Australian ticks of medical importance are reviewed through the lens of dermatology. [ABSTRACT FROM AUTHOR]

Plant growth-promoting rhizobacteria (PGPR) represent a set of microorganisms that play significant role in improving plant growth and controlling the phytopathogens. Unpredictable performance after the application of PGPR has been observed when these were shifted from in-vitro to in-vivo conditions due to the prevalence of various abiotic stress conditions. During growing period, the potato crop is subjected to a combination of biotic and abiotic stresses. Rhizoctonia solani, a soil-borne plant pathogen, causes reduced vigor and yield of potato crop worldwide. In the current study, multi-stress-tolerant rhizobacterial strain, Bacillus subtilis PM32, was isolated from field-grown potato with various plant growth promoting (PGP) traits including zinc and potassium solubilization, biological nitrogen fixation, ammonia and siderophore, as well as extracellular enzyme productions (cellulase, catalase, amylase, protease, pectinase, and chitinase). The strain PM32 exhibited a distinct potential to support plant growth by demonstrating production of indole-3-acetic acid (102.6 μM/mL), ACC-deaminase activity (1.63 μM of α-ketobutyrate/h/mg protein), and exopolysaccharides (2.27 mg/mL). By retarding mycelial growth of R. solani the strain PM32 drastically reduced pathogenicity of R. solani. The strain PM32 also suppressed the pathogenic activity significantly by impeding mycelial expansion of R. solani with inhibition co-efficient of 49.87. The B. subtilis PM32 also depicted significant tolerance towards salt, heavy metal (Pb), heat and drought stress. PCR based amplification of ituC and acds genes coding for iturin and ACC-deaminase activity respectively indicated potential of strain PM32 for lipopeptides production and ACC deaminase enzyme activity. Results of both in-vitro and pot experiments under greenhouse conditions depicted the efficiency of B. subtilis PM32 as a promising bio-control agent for R. solani infection together with enhanced growth of potato plants as deciphered from biomass accumulation, chlorophyll a, b, and carotenoid contents. Therefore, it was envisioned that application of indigenous multi-stress tolerant PGPR may serve to induce biotic and abiotic stress tolerance in crops/plants for pathogen control and sustainable global food supply. [ABSTRACT FROM AUTHOR]

A 56‐year‐old woman with hypohidrotic ectodermal dysplasia presented with a 10‐year history of persisting wart‐like skin lesions on her feet. Biopsy revealed changes of eccrine syringofibroadenoma. These lesions are rare, with only nine case reports describing an association with ectodermal dysplasia of hidrotic type (Clouston and Schopf's syndrome). To our knowledge, this is the first case of eccrine syringofibroadenoma developing in the hypohidrotic/anhidrotic subtype of ectodermal dysplasia. [ABSTRACT FROM AUTHOR]

The overall purpose of this research work is to investigate carotenoids content using spectrophotometric data of two famous cultivars of Pakistani mangoes (Ratol and Chaunsa) under different postharvest ripening treatments. The UV–VIS absorption results of these cultivars show absorption at wavelength positions 425, 446 and 467 nm which correspond to carotenoids specifically to β-carotene. In fruits and particularly in mangoes, synthesis of β-carotene is correlated with the ripening. Overall, every treatment has shown ripening of mango, but the concentration of β-carotene based on UV–VIS absorption intensity varies with treatment as well as with cultivars. Apart from trace elements (calcium arsenide and calcium phosphide) which are injurious to human health, these results show that in both cultivars, the synthesis of β-carotene is maximum when mangoes are ripened with calcium carbide. Additionally, these results also depict the difference in the content of these important pigments more than twice in Ratol cultivar when compared with Chaunsa. Agreeing with the results of UV–VIS absorption, Raman spectroscopy also shows comparable variations in β-carotene content for both mango cultivars. The Raman spectra of pulp, under different postharvest treatments, depict β-carotene specific characteristic peaks at 1003, 1150 and 1515 cm−1. In order to educate consumers regarding good quality foods, future study with more attention focused on studying the concentration of β-carotene in other varieties is also desirable. [ABSTRACT FROM AUTHOR]

The current study presents the application of fluorescence emission spectroscopy and synchronous fluorescence spectroscopy (SFS) coupled with chemometrics in diagnosing citrus canker disease in citrus species. Leaf samples were collected from random plants of grapefruit and Mexican lime species from an orchard. Fluorescence spectroscopy demonstrated the disease severity by predicting an increase in the blue–green spectral region and a decline in chlorophyll bands in the citrus leaves. As a result of the disease severity, characteristic changes in the SFS spectrum were observed. Noticeably, SFS provided additional information on the occurrence of significant bands of leaf fluorophores representing various biochemical changes in leaves at different disease stages. The current study led to the inference that a higher intensity of α-tocopherol and gallic acid is found in healthy and asymptomatic leaves; in contrast the band intensity of flavonoids, caffeic acid, tannins, flavins and chlorogenic acid increases in diseased samples, proportionally to the disease severity. Principal component analysis showed a clear separation between healthy and diseased samples. It is important to note that the asymptomatic samples were clustered with the symptomatic samples or remained as a separate group, thus revealing disease initiation, an observation which is impossible to make through visual examination. The results indicate that the spectral signatures obtained through front-face fluorescence spectroscopy as well as through SFS of citrus leaves could be used as fingerprints from the detection viewpoint. [ABSTRACT FROM AUTHOR]

The current study was designed to identify the stage for the diagnosis of disease before visible symptoms appeared. Fluorescence spectroscopy has been employed to identify disease signatures for its early diagnosis in rice plant leaves. Bacterial leaf blight (BLB) diseased and healthy leaf samples were collected from the rice fields in September, 2017 which were then used to record spectra using an excitation wavelength at 410 nm. The spectral range of emission was set from 420 to 800 nm which covers the blue–green and the chlorophyll bands. It was found that diseased leaves have a narrower ‘chlorophyll a’ band than healthy ones, and furthermore, that the emission band at 730 nm was either declined or depleted in the sample with high infection symptoms. In contrast, the blue–green region was observed to increase due to the emergence of disease. As the band intensity of chlorophyll decreases during infection, this decrease in chlorophyll content and increase in the blue–green spectral region could provide a new approach for predicting BLB at an early stage. The important finding was that the chlorophyll degradation and rise in the blue–green region take place in leaves with BLB or during BLB infection. Principal component analysis has been applied to spectral data which successfully separated diseased samples from healthy ones even with very small spectral variations. [ABSTRACT FROM AUTHOR]

The current study presents time dependent variations in the concentration of beta-carotene in carrot under different storage-temperature conditions using UV–VIS and Raman spectrophotometric techniques. The UV–VIS absorption spectra of beta-carotene extracted from carrot shows three distinct absorption peaks at 442, 467, and 500 nm with maximum absorption at 467 nm. These absorption peaks are very much reproducible and are assigned to β-carotene. Similarly, Raman spectra of carrot samples also confirmed the three main Raman peaks of beta-carotene at shift positions 1003, 1150, and 1515 cm−1. An overall decrease in beta-carotene content has been observed for time-temperature conditions. These results depict a decrease of about 40% in the content of beta-carotene when carrot samples were stored in a refrigerator (4 °C) for the first 20 d, whereas a decrease of about 25% was observed when carrot samples were stored in a freezer (−16 °C) for the same period. The objective of this study is to investigate the possible use of Raman spectroscopy and UV–VIS spectroscopy for quick and detailed analysis of changes (degradation) in beta-carotene content associated with time and temperature in storage (frozen foods) in order to promote quality foods for consumers. Future study with a greater focus on the concentration/content of beta-carotene in other fruits/vegetables is also desirable. [ABSTRACT FROM AUTHOR]

Raman spectroscopy based investigations of the molecular changes associated with an early stage of dengue virus infection (DENV) using a partial least squares (PLS) regression model is presented. This study is based on non-structural protein 1 (NS1) which appears after three days of DENV infection. In total, 39 blood sera samples were collected and divided into two groups. The control group contained samples which were the negative for NS1 and antibodies and the positive group contained those samples in which NS1 is positive and antibodies were negative. Out of 39 samples, 29 Raman spectra were used for the model development while the remaining 10 were kept hidden for blind testing of the model. PLS regression yielded a vector of regression coefficients as a function of Raman shift, which were analyzed. Cytokines in the region 775–875 cm−1, lectins at 1003, 1238, 1340, 1449 and 1672 cm−1, DNA in the region 1040–1140 cm−1 and alpha and beta structures of proteins in the region 933–967 cm−1 have been identified in the regression vector for their role in an early stage of DENV infection. Validity of the model was established by its R-square value of 0.891. Sensitivity, specificity and accuracy were 100% each and the area under the receiver operator characteristic curve was found to be 1. [ABSTRACT FROM AUTHOR]