Red Form Research Articles

Using Polymers and Pigments to Produce Laser Interference Rings

When a laser of sufficient intensity is shined into a pigmented transparent medium, the partially absorbed laser light can heat and change the refractive index of the medium in the path of the beam. This altered medium will in turn cause the transmitted laser light to thermally defocus into a series of concentric rings. Some solvents such as 2-propanol and a variety of polymers such as polystyrene, polyethylene terephthalate, and polydimethylsiloxane can be pigmented with a variety of colors. Samples of various colors can be used to spectacularly demonstrate characteristics of light absorption. For example, a 2-propanol solution containing methyl red in red acidic form will absorb a green laser and produce interference rings, but a solution of methyl red in yellow basic form will not. As another example, a red laser beam will pass unaffected through a red pigmented film, but the beam will heat a green film (e.g., from a green pigmented polyethylene terephthalate soda bottle) to produce interference rings. Additionally, since the pattern produced is based on the interference of light waves, these demonstrations reinforce concepts associated with the wave nature of light.

Biotechnological approaches to the reproduction of remontant forms of red raspberry

Rubus idaeus L. is one of the oldest and most widespread berry crops, which is cultivated for the excellent taste as well as for medical and dietary properties of berries. Rubus fruits contain a significant amount of vitamins A and C, anthocyanins, polyphenolic substances, which determines their high antioxidant activity. Remontant red raspberry forms are able to berry on annual shoots in the second half of summer, which extends the term of consumption of fresh berries by 1.5-2 months. However, many forms of remontant raspberry have a low potential for vegetative propagation compared to summer varieties, which makes them difficult to reproduce and to use in the breeding process. We investigated the possibility of increasing the efficiency of in vitro micropropagation of a remontant raspberry variety ʻBiryulevskaya’. The effects of 6-benzylaminopurine (6-BAP) at concentrations of 0.5–3 mg l-1 and thidiazuron (TDZ) at concentrations of 0.05–0.2 mg l-1 as well as doubled and tripled iron chelate Fe-EDTA (Ferric ethylenediamine-tetraacetic acid) doses were studied. We found the adding 1.0 mg l-1 6-BAP to the MS medium containing a triple dose of iron chelate, provided intensive proliferation of high quality adventitious shoots.

Effect of ultrasound waves on hematological parameters, behavior and conduction system of heart in vitro in BALB/c strain mouse

In this study research was carried out on 5 male adult BALB/c mouse with a weight of 18±5 g. The temperature was at 22±2 °C and animals were kept under the condition of 12 h of light and 12 h of darkness (light on at 08:00 am) and free access to water and standard diet. All 5 mice were affected by three different harmonic oscillations one time and after 24 hours 4 of them were affected by the same oscillations (Fig. 1) and one was placed separately for control. At the end of the experiment, after euthanasia using CO2 chamber blood samples were collected by cardiac puncture. We noticed that ultrasound waves 20 MHz changed mice red blood cells structure and we found pathological forms of erythrocytes. Analysing morphological structure of erythrocytes were determined 46 abnormal red blood structure forms and atypical cells (30 codocytes, 8 stomatocytes and 8 acantocytes). Moreover, we determined that changed some normal behavior characteristics and increased grooming process.

Addition of sodium ascorbate to extend the shelf-life of tuna meat fish: A risk or a benefit for consumers?

We investigate the effects of antimicrobial (sodium citrate tribasic, E331) and antioxidant (ascorbic acid, E300 and sodium ascorbate, E301) additives on the meat drip from defrosted yellowfin tuna fish loins obtained from the local market and horse heart myoglobin. The effects have been followed by electronic absorption, its second derivative spectra, and resonance Raman spectroscopies. Upon addition of the additives, a final form is reached after about 24 h. It is characterized by a 4 nm red-shifted Soret band compared to that typical of the oxy species (418 nm) but with similar Q bands. Resonance Raman experiments carried out in 16O2 and 18O2 allowed us to identify the presence of the native oxy form coexisting with a second oxygen bound species, characterized by a ν(FeO2) stretching frequency upshifted 7 cm−1 compared to the native oxy form and with a greater (33 cm−1) isotopic shift in 18O2. These data suggest the presence of a highly bent ligand conformation. The new species induced by the addition of the additives imparts a red colour to the tuna fish meat, a characteristic that is of some concern. In fact, the presence of the new red form can mask the aging of the product that, consequently, might contain histamine. Furthermore, the electronic absorption spectrum is very similar to that of the tuna fish myoglobin carbon monoxide complex, which has important regulatory consequences. Carbon monoxide treatment of tuna is banned in the EU for masking the effects of aging on the appearance of meats.

Novel Phototransformable Fluorescent Protein SAASoti with Unique Photochemical Properties.

SAASoti is a unique fluorescent protein (FP) that combines properties of green-to-red photoconversion and reversible photoswitching (in its green state), without any amino acid substitutions in the wild type gene. In the present work, we investigated its ability to photoswitch between fluorescent red (‘on’) and dark (‘off’) states. Surprisingly, generated by 400 nm exposure, the red form of SAASoti (R1) does not exhibit any reversible photoswitching behavior under 550 nm illumination, while a combination of prior 470 nm and subsequent 400 nm irradiation led to the appearance of another—R2—form that can be partially photoswitched (550 nm) to the dark state, with a very fast recovery time. The phenomenon might be explained by chemical modification in the chromophore microenvironment during prior 470 nm exposure, and the resulting R2 SAASoti differs chemically from the R1 form. The suggestion is supported by the mass spectrometry analysis of the tryptic peptides before and after 470 nm light exposure, that revealed Met164 oxidation, as proceeds in another dual phototransformable FP, IrisFP.

Red blood cells state and calcium content of in the blood plasma during physical activity in marathon runners of various qualifications

The aim of the work is to investigate the morpho-functional state of peripheral blood erythrocytes and the content of Ca2+ in the blood plasma during physical exercise in marathoners of different qualifications.
 Material and methods. The studies were conducted in three groups of marathoners aged 20–25 years old with conditionally high, medium and low performance. Exercise was performed for 90 minutes on a bicycle ergometer with a given power. The study of peripheral blood erythrocytes was performed before and after exercise. The osmotic resistance of erythrocytes, the content of Ca2+ and free fatty acids in the blood were determined. Morphological study of erythrocytes was performed using a scanning electron microscope and stained by standard techniques. The red blood cell form index was determined by a special formula. Changing the content of Ca2+ enhances lipid melting, increases membrane fluidity and increases surface tension, with the result that the discocytes are stretched and thinned, the central pits deepen and the surface roughness increases, the volume and number of conical pores, and peripheral blood erythrocytes density.
 Results. Marathon runners of different groups after physical exercise differed in terms of the frequency of cardiac sweeps, the content of free fatty acids and the osmotic resistance of red blood cells. This is closely correlated with changes in the electrolyte and metric composition of erythrocytes and the presence of their reversible and irreversible forms in the general circulation after exercise.
 Conclutions. Physical activity causes structural and functional reorganization of erythrocytes, which is based on a change in their microelement composition, a decrease in osmotic resistance, mainly in poorly trained marathoners, and the appearance of various forms of erythrocytes against the background of the destruction of degenerative forms and an increase in the active release of young forms, which is a sign of high adaptive capacity in highly skilled athletes.

Cu+ Contributes to the Orange Carotenoid Protein-Related Phycobilisome Fluorescence Quenching and Photoprotection in Cyanobacteria.

Photosynthesis starts with absorption of light energy by using light-harvesting antenna complexes (LHCs). Overexcitation of LHCs and subsequent photosystems, however, is damaging and can be lethal. The orange carotenoid protein (OCP) protects most cyanobacteria from photodamage by dissipating excessive excitation energy harvested by phycobilisomes (PBS, LHCs) as heat. OCP has two states: the orange, inactive OCP (OCPO) and the red, active OCP (OCPR), with the latter able to bind PBS at a ratio of 2:1 and execute photoprotection. Conversion of OCPO to OCPR is driven by blue light absorption. Previous work indicated that in the presence of Cu2+, photoactivation of OCP can result in it being locked in its red form OCPR. The molecular mechanism of such chemical conversion, however, remains unclear. Here, we demonstrated that Cu+ can convert OCPO to OCPR under anaerobic conditions independent of light illumination. Interestingly, in the presence of Cu2+ and ascorbic acid, a ubiquitous reductant in photosynthetic organisms, the conversion of OCPO to OCPR can also take place spontaneously in the dark, indicative of a locked OCPR-Cu+ complex. Furthermore, our functional and structural studies indicate that OCPR-Cu+ can interact with PBS and trigger PBS fluorescence quenching. We hypothesize that copper ion, a redox-active component, may synergistically play an important role in the regulation of nonphotochemical quenching in cyanobacteria under stress conditions.

Chemical composition of floral scents from three Plumeria rubra L. (Apocynaceae) forms linked to petal color proprieties

The floral scents of three forms of cultivated Plumeria rubra L. were evaluated through mass flowering phenology using the dynamic headspace adsorption method and were identified with coupled gas chromatography and mass spectrometry. The forms P. rubra f. acutifolia and P. rubra f. lutea had white and yellow flower petals, respectively, and the flower petals of P. rubra f. rubra were red. Although 68 components of the flower scents of the three forms were recorded in different proportions, only 14 chemical compounds were identified with statistically significance. The main volatile compounds in the red form of P. rubra L. were fatty acid derivatives (56.75%). The main compounds in the white and yellow forms of P. rubra L. were benzenoid and terpene, with proportions of 48.38% and 33.33% in P. rubra f. acutifolia and proportions of 42.30% and 47.43% in P. rubra f. lutea, respectively. These differences in the flower scents might be one result of the minor genetic differences between these forms, similar to the role of genetic differences in the flower color combinations of the three forms. We conclude that petal color traits can, to some extent, reflect differences in floral scent compositions and that minor genetic differences of different plant forms exert impacts not only on flower color but also on the phytochemistry of floral scents.

Bent HgI2 Molecules in the Melt and Sulfide Glasses: Implications for Nonlinear Optics

Nonlinear optical (NLO) crystals are widely used in advanced photonic technologies for second harmonic and difference frequency generation (SHG and DFG, respectively), producing coherent light at frequencies where existing lasers are unavailable. Isotropic glasses do not exhibit SHG or DFG, except temporarily induced anisotropy under external stimuli. However, recent reports on glasses with chiral structural motifs show promising permanent NLO properties. We propose an alternative solution: hybrid molecular/network glasses with noncentrosymmetric HgI2 monomers. Mercury(II) iodide consists of linear HgI2 triatomic molecules in the vapor phase and in the yellow orthorhombic polymorph stable above 400 K. At lower temperatures, the tetragonal red form is composed of corner-sharing HgI4/2 tetrahedra forming a layered extended framework. There is a gap in the molecular evolution; direct structural measurements of the liquid HgI2 phase are missing. Using high-energy X-ray scattering, pulsed neutron diffraction, ...

High genetic diversity in a 'recent outbreak' spider mite, Tetranychus pueraricola, in mainland China.

Tetranychus pueraricola is a newly reported spider mite that occurs frequently in mainland China. It is possible that this species was introduced from elsewhere and became a serious pest recently. However, the correct identification of red-pigmented spider mites has repeatedly proven problematic. There is also the possibility that T. pueraricola in China was long misidentified as its sibling species, Tetranychus urticae (red form). To test which of these two scenarios is the more likely, individuals from 14 populations of T. pueraricola and five populations of T. urticae (red form) in China were sampled and genotyped using mitochondrial COI and microsatellite loci. Unlike a recent invasive species, the genetic diversity of T. pueraricola was very high with high mitochondrial genetic diversity (16 haplotypes), high effective alleles (Ne = 2.038 ± 0.081) and expected heterozygosity (He = 0.395 ± 0.016). Surprisingly, we found that all T. urticae (red form) populations shared only one mitochondrial haplotype and showed quite low genetic diversity (Ne = 1.443 ± 0.055; He = 0.234 ± 0.025) which was even lower than that of the green form of T. urticae in mainland China from a previous study. We did not detect significant signals of recent bottlenecks for most populations from both species. These results suggest T. pueraricola is unlikely to be a recent invasive pest but a species that has existed in China for a long time. It is probable that T. pueraricola in China has long been misidentified as T. urticae (red form).

The experience of application of antiscar combined agent with boswellic and hyaluronic acids and cepalin in patients with scars at early stages of their development

The article describes the experience of application of the combined antiscar agent containing boswellic acid, cepalin, hyaluronic acid and allantoin with the subsequent application of the prolonged action pressing patch with the matrix of active release of cepalin and allantoin at the early stages of formation and maturation of scars in the patients with postoperative, post-burn scars and traces after cosmetic manipulations in the form of persistent skin redness. A comparison of the efficacy of two therapy schemes for 43 patients aged 18 to 45 in two groups was shown. When evaluating the effectiveness of the therapy by analyzing the data of evaluation scales, ultrasound, dermatoscopy, a greater effectiveness of the combined antiscar agent and pressure patch in comparison with the use of hydrating agents and silicone patches was noted.

Imaging through the Whole Brain of Drosophila at λ/20 Super-resolution

SummaryRecently, many super-resolution technologies have been demonstrated, significantly affecting biological studies by observation of cellular structures down to nanometer precision. However, current super-resolution techniques mostly rely on wavefront engineering or wide-field imaging of signal blinking or fluctuation, and thus imaging depths are limited due to tissue scattering or aberration. Here we present a technique that is capable of imaging through an intact Drosophila brain with 20-nm lateral resolution at ∼200 μm depth. The spatial resolution is provided by molecular localization of a photoconvertible fluorescent protein Kaede, whose red form is found to exhibit blinking state. The deep-tissue observation is enabled by optical sectioning of spinning disk microscopy, as well as reduced scattering from optical clearing. Together these techniques are readily available for many biologists, providing three-dimensional resolution of densely entangled dendritic fibers in a complete Drosophila brain. The method paves the way toward whole-brain neural network studies and is applicable to other high-resolution bioimaging.

ВПЛИВ ЕКСТРАКТІВ І СУСПЕНЗІЙ ЯКОНА (SMALLANTHUS SONCHIFOLIA) НА ЗМІНИ СТРУКТУРИ ВУГЛЕВОДНИХ ДЕТЕРМІНАНТ ГЛІКОКОН’ЮГАТІВ МЕМБРАН ЕРИТРОЦИТІВ ЗА УМОВ ЕКСПЕРИМЕНТАЛЬНОГО ЦУКРОВОГО ДІАБЕТУ

The article presents the results of the study dedicated to the influence of yacons leaves and root tubers water extracts and suspensions of roots in a dose of 500 mg / kg on changes in the structure of erythrocytes membranes glycoconjugates carbohydrate determinants and erythrocytes resistance to acidic hemolytic activity under conditions of experimental diabetes mellitus (EDM) type 1. Investigated pathology is accompanied by a violation of the functional state and by a change in the glycane profile of the erythrocyte plasma membrane. In particular, it has been established that the development of diabetes mellitus is accompanied by a decrease in the stability of erythrocytes membranes to the action of acid hemolysis, an increase in the number of physiologically old erythrocytes and a decrease in the content of sialic acids in oligosaccharide glycoconjugates of erythrocyte membranes attached by (α2→6)- and (α2→3)- glycoside bonds to subterminal sugars, as well as the growth of the expression of subterminal galactose residues. At administration of the studied extracts and suspensions to animals with an EDM the positive effect on the physicochemical state of the erythrocyte membranes was noted. The use of yacons extracts and suspensions cause in bloodstream the growth of number of erythrocytes young forms and middle-aged cells, on the background lowering of red blood cells old forms. It was established that the most pronounced effect is inherent in water suspensions of yacons roots tubers, the application of which leads to the normalization of the structure of the membranes glycocalyx of red blood cells, to normalization of sialic acids content on the surface of erythrocytes, with the simultaneous decrease in the content of subterminal galactose residues. Corrective effect of investigated extracts and suspensions on the physicochemical state of erythrocyte membranes can be an experimental confirmation of the need for the development of functional foods based on yacon, which can be used in complex therapy of diabetes and prevent the harmful effects of hyperglycemia.

Flavonoid Productivity Optimized for Green and Red Forms of Perilla frutescens via Environmental Control Technologies in Plant Factory

Perilla frutescens (Lamiaceae) is a dietary staple in Asia. It is an abundant source of flavonoids that are bioactively beneficial to human health and fitness. The current popularity of plant-based consumption is being driven by the healthful benefits of bioactive nutrition, and the concentration of bioactive agents found in raw plant materials is an important factor in the assessment of food quality. To test the feasibility of promoting flavonoid productivity in perilla plants via environmental treatment, plant factory technology was applied to perilla plant cultivation. Apigenin (AG) and luteolin (LT) are two of the most potent anticarcinogenic flavonoids in perilla, and these are also found in many vegetables and fruits. Quantitative analysis of AG and LT was conducted on plants cultivated under nine environmental forms of treatment imposed by three levels of light intensity (100, 200, and 300 µmol·m−2·s−1) combined with three levels of nutrient-solution concentration (1.0, 2.0, and 3.0 dS·m−1) for hydroculture. The contents of AG in green and red perilla plant were increased by high nutrient-solution levels under the same light intensity. In green perilla, the highest concentration of AG (8.50 µg·g−1) was obtained under treatment of the highest level of nutrient-solution (3.0 dS·m−1) and 200 µmol·m−2·s−1 of light intensity, whereas in red perilla, the highest concentration of AG (6.38 µg·g−1) was achieved from the highest levels of both of these forms of treatment (300 µmol·m−2·s−1 and 3.0 dS·m−1). The increase in AG content per plant between the lowest and the highest levels was recorded by 6.4-fold and 8.6-fold in green and red perilla, respectively. The behavior of LT concentration differed between green and red forms of perilla. LT concentration in red perilla was enhanced under nutrient deficiency (1.0 dS·m−1) and affected by light intensity. Different responses were observed in the accumulations of AG and LT in red and green perilla during treatments, and this phenomenon was discussed in terms of biosynthetic pathways that involve the expressions of phenylpropanoids and anthocyanins. The total yield of flavonoids (AG and LT) was improved with the optimization of those forms of treatment, with the best total yields: 33.9 mg·plant−1 in green Perilla; 10.0 mg·plant−1 in red perilla, and a 4.9-fold and a 5.4-fold increase was recorded in green and red perilla, respectively. This study revealed that flavone biosynthesis and accumulation in perilla plants could be optimized via environmental control technologies, and this approach could be applicable to leafy vegetables with bioactive nutrition to produce a stable industrial supply of high flavonoid content.

Assessment of Dimensions in Order to Aid Classification of European Red Mite and Two-Spotted Spider Mite by Means of Digital Imaging of Infected Leaves

Abstract The methods currently used to assess orchard infestation are time-consuming and do not take into account non-adult forms of mites, due to their small size. Advance in digital imaging technology, however, has resulted in the discovery of a more viable method to enable a fast and reliable assessment of orchard infestation. Digital images of infected apple leaves were made and examined for the presence of European red mites and two-spotted spider mites. As well as adult mites, non-adult European red mite forms were also encountered. After extracting all objects considered as mites from the image, imaging software was then used to assess their dimension and shape parameters. Length, width, area, and equivalent diameter were different for all three observed mite groups: adult female European red mites, possible non-adult European red mites and adult two-spotted spider mites. Differences in circularity and elongation were found in adult two-spotted spider mites and various forms of European red mites, while the perimeter was similar in adult European red mites and two-spotted spider mites, and different in the non-adult forms of European red mites. However, as the ranges of 95% prediction intervals for these features overlap, a combination of at least two features as well as employing statistical procedures may greatly increase the probability of appropriate classification of the observed objects as different mites.

Acaricide resistance in Tetranychus urticae red form (Acari: Tetranychidae) collected from strawberry in southern Turkey: Bioassay and biochemical studies

Recent population outbreaks of Tetranychus urticae Koch (red form) (Acari: Tetranychidae) were observed in strawberry fields in southern Turkey. Growers frequently complained that acaricides becoming an inefficient means of controlling this polyphagous pest. Therefore, a laboratory based bioassay and biochemical tests were conducted to determine comparative acaricide resistance status of five fields and a lab population of T. urticae. Larval bioassays were conducted using etoxazole and spiromesifen, whereas adult bioassays were performed with abamectin and tebufenpyrad. Kinetic esterase and glutathione S-transferase (GST) enzyme activities were also determined using a microplate reader. When compared to the lab population, based on LC50 values, the resistance rations of field populations were found between 2.39–7.86, 6.80–15.39, 4.61–9.73, and 5.51–12.47-fold for abamectin, etoxazole, spiromesifen and tebufenpyrad, respectively. Total esterase and GST activities of field populations were much higher than of the lab population. A 7.72–10.69 mOD/min/mg protein and a 5.92–7.56 mOD/min/mg protein, esterase and GST enzyme activities were determined for field populations, respectively. Whereas these enzyme activities were found to be 3.83 and 5.49 mOD/min/mg protein for the susceptible lab population, respectively. The higher detoxification enzyme activities indicate that these two enzymes play an important role in metabolic pathway of acaricides in different T. urticae populations.

Photoprotection enhanced by red cell wall pigments in three East Antarctic mosses

BackgroundAntarctic bryophytes (mosses and liverworts) are resilient to physiologically extreme environmental conditions including elevated levels of ultraviolet (UV) radiation due to depletion of stratospheric ozone. Many Antarctic bryophytes synthesise UV-B-absorbing compounds (UVAC) that are localised in their cells and cell walls, a location that is rarely investigated for UVAC in plants. This study compares the concentrations and localisation of intracellular and cell wall UVAC in Antarctic Ceratodon purpureus, Bryum pseudotriquetrum and Schistidium antarctici from the Windmill Islands, East Antarctica.ResultsMultiple stresses, including desiccation and naturally high UV and visible light, seemed to enhance the incorporation of total UVAC including red pigments in the cell walls of all three Antarctic species analysed. The red growth form of C. purpureus had significantly higher levels of cell wall bound and lower intracellular UVAC concentrations than its nearby green form. Microscopic and spectroscopic analyses showed that the red colouration in this species was associated with the cell wall and that these red cell walls contained less pectin and phenolic esters than the green form. All three moss species showed a natural increase in cell wall UVAC content during the growing season and a decline in these compounds in new tissue grown under less stressful conditions in the laboratory.ConclusionsUVAC and red pigments are tightly bound to the cell wall and likely have a long-term protective role in Antarctic bryophytes. Although the identity of these red pigments remains unknown, our study demonstrates the importance of investigating cell wall UVAC in plants and contributes to our current understanding of UV-protective strategies employed by particular Antarctic bryophytes. Studies such as these provide clues to how these plants survive in such extreme habitats and are helpful in predicting future survival of the species studied.

Improved methods for marking active neuron populations

Marking functionally distinct neuronal ensembles with high spatiotemporal resolution is a key challenge in systems neuroscience. We recently introduced CaMPARI, an engineered fluorescent protein whose green-to-red photoconversion depends on simultaneous light exposure and elevated calcium, which enabled marking active neuronal populations with single-cell and subsecond resolution. However, CaMPARI (CaMPARI1) has several drawbacks, including background photoconversion in low calcium, slow kinetics and reduced fluorescence after chemical fixation. In this work, we develop CaMPARI2, an improved sensor with brighter green and red fluorescence, faster calcium unbinding kinetics and decreased photoconversion in low calcium conditions. We demonstrate the improved performance of CaMPARI2 in mammalian neurons and in vivo in larval zebrafish brain and mouse visual cortex. Additionally, we herein develop an immunohistochemical detection method for specific labeling of the photoconverted red form of CaMPARI. The anti-CaMPARI-red antibody provides strong labeling that is selective for photoconverted CaMPARI in activated neurons in rodent brain tissue.

A Rapid Analytical Method for the Selective Quenching-Free Determination of Thiols by GC-FPD

A rapid method is introduced, which facilitates the selective gas chromatography–flame photometric detection (GC–FPD) analysis of thiols. The method uses lead oxide particles or plumbite solution to complex thiols into a solid lead thiolate moiety that can be physically separated from complex sample matrices and then reconstituted as the original thiol in a simple replacement solvent for analysis. While both red or yellow forms of lead oxide are found to remove thiols from sample solutions, the latter does so about 10 times faster than the former. Comparatively, though, plumbite solution is most rapid in this regard and is still 10 fold faster than solid yellow lead oxide. For example, 98 ± 1% (n = 3) of a 1-butanethiol standard in hexane (600 ng µL− 1) was extracted after only 2 min of contact with a 0.06 M plumbite solution. The method allows thiols to be selectively isolated from co-eluting peaks and other sulfur species, which can simplify their determination. It also allows thiols to be removed from complex hydrocarbon matrices for analysis, which can greatly reduce interference from signal quenching when using a conventional FPD. For instance, analysis of a thiol standard in a commercial gasoline by this method showed that the FPD sulfur signal increased from 16 to 97% of its expected value by removing the quenching hydrocarbon interference. Accordingly, results indicate that this method could be a useful alternative approach for the selective analysis of such thiol-containing samples.

Rate of malignant transformation of oral lichen planus: A systematic review.

The aim of this study was to systematically review the literature to determine: (a) the malignant transformation rate (TR) of oral lichen planus (OLP) and its risk factors; (b) whether or not oral lichenoid lesions (OLL) have a different malignant TR. PubMed, Scopus, and Web of Science were used as search engines: only observational, full-length, English language studies were investigated. PRISMA protocol was used to evaluate and present results. PROSPERO registration code is CRD42016048529. Among 7,429 records screened, only 21 were included in this review. Ninety-two of 6,559 patients developed oral squamous cell carcinoma, with an overall TR of 1.40% (1.37% for OLP and 2.43% for OLL), an annual TR of 0.20%. Female gender, red clinical forms, and tongue site seem to slightly increase the transformation risk. This systematic review confirms that both OLP and OLL, the latter with a slightly higher TR, may be considered potentially malignant disorders and suggest that erosive type, female gender and tongue site should be considered as risk factors for OLP transformation. Major efforts should be done to establish strict clinical and histological criteria to diagnose OLP and to perform sounder methodological observational studies.