Fraud-proof methylcellulose-based fish freshness indicator: Reversibility in halochromic sensing of basic volatiles is tailored by ionic strength.

Food from animal sources (e.g., fish) represents the food group most likely to disseminate diseases to humans. To prevent food contamination and foodborne illnesses, intelligent packaging has been developed to monitor fish freshness by real-time tracking their physicochemical attributes and informing consumers about their conservation state. In this context, we investigated the influence of ionic strength (IS) provided by CaCl2 on the chromatic response of anthocyanin açai extracts incorporated into methylcellulose (MC) within hydrocolloid-based colorimetric sensors for monitoring the freshness of Lambari fish. The color sensitivity of the sensors was modulated by IS in the presence of NH3 volatile and/or TVB-N. Increasing IS led to a plasticizing effect in the MC matrix, which influenced the chromatic properties of anthocyanin in the presence of NH3 and/or TVB-N. The perception of distinct colors by untrained eyes improved from 10 min with the control sensor to 2.5 min for sensors with IS >50 mM. Adjusting the IS to 500 mM with LiCl, CaCl2, or MgCl2 resulted in gray-green, blue, or moss-green colors, respectively, diverging from the control sensor's color (pink and gray) after 10 min of ammonia exposure, confirming salt-induced copigmentation. Color irreversibility in the sensors was achieved when the IS exceeded 250 mM. Through principal component analysis, we statistically validate the efficacy of the sensor in assessing the freshness of Lambari fish. The sensor maintained its color-change capability even after 60 d of storage and was able to classify Lambari fish freshness according to Brazilian and European standards. This study elucidates the interrelation between the structures and properties of natural compounds such as MC, anthocyanin, and CaCl2, providing a method to control the chromatic properties of sensors intended to monitor food quality, safety, and shelf-life.

Increase in methicillin-resistant Staphylococcus spp. colonization among pregnant individuals during COVID-19 pandemic.

Methicillin-resistant Staphylococcus (MRS) has been associated with neonatal infections, with colonization of the anovaginal tract being the main source of vertical transmission. The COVID-19 pandemic has altered the frequency of antibiotic usage, potentially contributing to changes in the dynamics of bacterial agents colonizing humans. Here we determined MRS colonization rates among pregnant individuals attending a single maternity in Rio de Janeiro, Brazil before (January 2019-March 2020) and during (May 2020-March 2021) the COVID-19 pandemic. Anovaginal samples (n = 806 [521 samples before and 285 during the pandemic]) were streaked onto chromogenic media. Colonies were identified by MALDI-TOF MS. Detection of mecA gene and SCCmec typing were assessed by PCR and antimicrobial susceptibility testing was done according to CLSI guidelines. After the onset of the pandemic, MRS colonization rates increased significantly (p < 0.05) from 8.6% (45) to 54.7% (156). Overall, 215 (26.6%) MRS isolates were detected, of which S. haemolyticus was the most prevalent species (MRSH, 84.2%; 181 isolates). SCCmec type V was the most frequent among MRS (63.3%; 136), and 31.6% (68) of MRS strains had a non-typeable SCCmec, due to new combinations of ccr and mecA complexes. Among MRS strains, 41.9% (90) were resistant to at least 3 different classes of antimicrobial agents, and 60% (54) of them were S. haemolyticus harboring SCCmec V. MRS colonization rates and the emergence of multidrug-resistant variants detected in this study indicate the need for continuing surveillance of this important pathogen within maternal and child populations.

Unusual magnetic resonance imaging findings of cystic bone lesions in congenital generalized lipodystrophy.

Cystic bone lesions are the hallmark of skeletal abnormalities in patients with congenital generalized lipodystrophy (CGL). However, their pathophysiology is still unclear and theories about their origin remain largely speculative. This article reports on a patient with CGL and cystic bone lesions, some of them with unusual magnetic resonance imaging (MRI) findings that include elevated signal intensity on T1-weighted images and fluid-fluid levels, the latter evolving to a more "classic" cystic appearance on follow-up. Even though similar findings were first described almost 30 years ago, little attention was given to them back then; furthermore, other than the present report, no other study has performed sequential exams to follow their evolution in serial MRI. The authors conduct a review of the literature, hypothesizing that these remarkable findings may reflect an intermediate stage in the process of cystification of the abnormal bone marrow, incapable to perform adipose conversion, lending factual support to the modern theories about this issue.

Field-resolved THz-pump laser-probe measurements with CEP-unstable THz light sources.

Radiation sources with a stable carrier-envelope phase (CEP) are highly demanded tools for field-resolved studies of light-matter interaction, providing access both to the amplitude and phase information of dynamical processes. At the same time, many coherent light sources, including those with outstanding power and spectral characteristics lack CEP stability, and so far could not be used for this type of research. In this work, we present a method enabling linear and non-linear phase-resolved terahertz (THz) -pump laser-probe experiments with CEP-unstable THz sources. THz CEP information for each pulse is extracted using a specially designed electro-optical detection scheme. The method correlates the extracted CEP value for each pulse with the THz-induced response in the parallel pump-probe experiment to obtain an absolute phase-resolved response after proper sorting and averaging. As a proof-of-concept, we demonstrate experimentally field-resolved THz time-domain spectroscopy with sub-cycle temporal resolution using the pulsed radiation of a CEP-unstable infrared free-electron laser (IR-FEL) operating at 13 MHz repetition rate. In spite of the long history of IR-FELs and their unique operational characteristics, no successful realization of CEP-stable operation has been demonstrated yet. Being CEP-unstable, IR-FEL radiation has so far only been used in non-coherent measurements without phase resolution. The technique demonstrated here is robust, operates easily at high-repetition rates and for short THz pulses, and enables common sequential field-resolved time-domain experiments. The implementation of such a technique at IR-FEL user end-stations will facilitate a new class of linear and non-linear experiments for studying coherent light-driven phenomena with increased signal-to-noise ratio.

Terahertz-slicing - an all-optical synchronization for 4th generation light sources.

A conceptually new approach to synchronizing accelerator-based light sources and external laser systems is presented. The concept is based on utilizing a sufficiently intense accelerator-based single-cycle terahertz pulse to slice a thereby intrinsically synchronized femtosecond-level part of a longer picosecond laser pulse in an electro-optic crystal. A precise synchronization of the order of 10 fs is demonstrated, allowing for real-time lock-in amplifier signal demodulation. We demonstrate successful operation of the concept with three benchmark experiments using a 4th generation accelerator-based terahertz light source, i.e. (i) far-field terahertz time-domain spectroscopy, (ii) terahertz high harmonic generation spectroscopy, and (iii) terahertz scattering-type scanning near-field optical microscopy.

Optical computing of quantum revivals.

Interference is the mechanism through which waves can be structured into the most fascinating patterns. While for sensing, imaging, trapping, or in fundamental investigations, structured waves play nowadays an important role and are becoming the subject of many interesting studies. Using a coherent optical field as a probe, we show how to structure light into distributions presenting collapse and revival structures in its wavefront. These distributions are obtained from the Fourier spectrum of an arrangement of aperiodic diffracting structures. Interestingly, the resulting interference may present quasiperiodic structures of diffraction peaks on a number of distance scales, even though the diffracting structure is not periodic. We establish an analogy with revival phenomena in the evolution of quantum mechanical systems and illustrate this computation numerically and experimentally, obtaining excellent agreement with the proposed theory.

Pulse- and field-resolved THz-diagnostics at 4 t h generation lightsources.

Multi-color pump-probe techniques utilizing modern accelerator-based 4th generation light sources such as X-ray free electron lasers or superradiant THz facilities have become important science drivers over the past 10 years. In this type of experiments the precise knowledge of the properties of the involved accelerator-based light pulses crucially determines the achievable sensitivity and temporal resolution. In this work we demonstrate and discuss the powerful role pulse- and field-resolved- detection of superradiant THz pulses can play for improving the precision of THz pump - femtosecond laser probe experiments at superradiant THz facilities in particular and at 4th generation light sources in general. The developed diagnostic scheme provides real-time information on the properties of individual pulses from multiple accelerator based THz sources and opens a robust way for sub femtosecond timing. Correlations between amplitude and phase of the pulses emitted from different superradiant THz sources furthermore provide insides into the properties of the driving electron bunches and is of general interest for the ultra-fast diagnostics at 4th generation light sources.

Reverse transcriptase droplet digital PCR to identify the emerging vesicular virus Senecavirus A in biological samples.

Senecavirus A (SVA) belonging to the family Picornaviridae, genus Senecavirus was incidentally isolated in 2002 from the PER.C6 (transformed foetal retinoblast) cell line. However, currently, this virus is associated with vesicular disease in swine and it has been reported in countries such as the United States of America, Canada, China, Thailand and Colombia. In Brazil, the SVA was firstly reported in 2015 in outbreaks of vesicular disease in swine, clinically indistinguishable of Foot-and-mouth disease, a contagious viral disease that generates substantial economic losses. In the present work, it was standardized a diagnostic tool for SVA based on RNA reverse transcriptase droplet digital PCR (RT-ddPCR) using one-step and two-step approaches. Analytical sensitivity and specificity were done in parallel with real-time PCR, RT-qPCR (one-step and two-step) for comparison of sensitivity and specificity of both methods. In the standardization of RT-ddPCR, the double-quenched probe and the temperature gradient were crucial to reduce background and improve amplitude between positive and negative droplets. The limit of detection and analytical specificity of techniques of one-step techniques showed superior performance than two-step methods described here. Additionally, the results showed 94.2% concordance (p < 0.001) for RT-ddPCR and RT-qPCR using the one-step assay approach and biological samples from Brazilian outbreaks of Senecavirus A. However, ddRT-PCR had a better performance than RT-PCR when swine serum pools were tested. According to the results, the one-step RT-ddPCR and RT-qPCR is highlighted to be used as an auxiliary diagnostic tool for Senecavirus A and for viral RNA absolute quantification in biological samples (RT-ddPCR), being a useful tool for vesicular diseases control programs.

Renewing Felsenstein's phylogenetic bootstrap in the era of big data.

Felsenstein's application of the bootstrap method to evolutionary trees is one of the most cited scientific papers of all time. The bootstrap method, which is based on resampling and replications, is used extensively to assess the robustness of phylogenetic inferences. However, increasing numbers of sequences are now available for a wide variety of species, and phylogenies based on hundreds or thousands of taxa are becoming routine. With phylogenies of this size Felsenstein's bootstrap tends to yield very low supports, especially on deep branches. Here we propose a new version of the phylogenetic bootstrap in which the presence of inferred branches in replications is measured using a gradual 'transfer' distance rather than the binary presence or absence index used in Felsenstein's original version. The resulting supports are higher and do not induce falsely supported branches. The application of our method to large mammal, HIV and simulated datasets reveals their phylogenetic signals, whereas Felsenstein's bootstrap fails to do so.

Viruses associated with congenital tremor and high lethality in piglets.

The recently described atypical porcine pestivirus (APPV) has been associated with congenital tremor (CT) type A-II in piglets in different countries. Another important neurological pathogen of pigs is porcine teschovirus (PTV), which has been associated with non-suppurative encephalomyelitis in pigs with severe or mild neurological disorders. There have been no reports of APPV and/or PTV coinfection associated with CT or encephalomyelitis in Brazilian pig herds. The aim of this study was to describe the pathological and molecular findings associated with simultaneous infection of APPV and PTV in piglets with clinical manifestations of CT that were derived from a herd with high rates of CT-associated lethality. In 2017, three piglets from the same litter with CT died spontaneously. The principal pathological alterations in all piglets were secondary demyelination and hypomyelination at the cerebellum, brainstem and spinal cord confirmed by histopathology and luxol fast blue-cresyl violet stain. Additional significant pathological findings included multifocal neuronal necrosis, neuronophagia and gliosis found in the cerebral cortex and spinal cord of all piglets, while atrophic enteritis and mesocolonic oedema were observed in some of them. APPV and PTV RNA were detected in the central nervous system of affected piglets, and PTV was also detected in the intestine and faeces. The pathological alterations and molecular findings together suggest a dual infection due to APPV and PTV at this farm. Moreover, the combined effects of these pathogens can be attributed to the elevated piglet mortality, as coinfections involving PTV have a synergistic effect on the affected animals.

Sequencing of bimaxillary surgery in the correction of vertical maxillary excess: retrospective study.

The aim of this study was to evaluate the precision of bimaxillary surgery performed to correct vertical maxillary excess, when the procedure is sequenced with mandibular surgery first or maxillary surgery first. Thirty-two patients, divided into two groups, were included in this retrospective study. Group 1 comprised patients who received bimaxillary surgery following the classical sequence with repositioning of the maxilla first. Patients in group 2 received bimaxillary surgery, but the mandible was operated on first. The precision of the maxillomandibular repositioning was determined by comparison of the digital prediction and postoperative tracings superimposed on the cranial base. The data were tabulated and analyzed statistically. In this sample, both surgical sequences provided adequate clinical accuracy. The classical sequence, repositioning the maxilla first, resulted in greater accuracy for A-point and the upper incisor edge vertical position. Repositioning the mandible first allowed greater precision in the vertical position of pogonion. In conclusion, although both surgical sequences may be used, repositioning the mandible first will result in greater imprecision in relation to the predictive tracing than repositioning the maxilla first. The classical sequence resulted in greater accuracy in the vertical position of the maxilla, which is key for aesthetics.

Vaccinia virus detection in dairy products made with milk from experimentally infected cows.

Vaccinia virus (VACV) is the agent of bovine vaccinia (BV), an emerging zoonosis that causes exanthematic lesions on the teats of dairy cows and on the hands of milkers. The virus has been detected in the milk of naturally infected cows. The objective of this study was to investigate and quantify VACV DNA as well as the presence of infectious virus particles in samples of cheese curd, cheese whey and pasteurized milk produced using milk from cows experimentally inoculated with VACV-GP2, a Brazilian isolate of VACV (VACV-BR). VACV DNA was detected in samples of cheese and pasteurized milk at different time points, even after the resolution of the typical lesions caused by VACV, which occurred after 22 days post-infection (dpi), on average. Moreover, it was possible to detect infectious viral particles in cheese samples on alternate days until 27 dpi. The presence of both VACV DNA and infectious viral particles in cheese samples throughout the clinical course of BV and even after the disappearance of the typical clinical signs of disease draws attention to the risk associated with consumption of the cheese. Furthermore, VACV-contaminated milk and cheese may represent an occupational risk to cheesemakers who often manipulate milk and cheese curd without wearing gloves.

Coexistence of spondyloarthritis and joint hypermobility syndrome: rare or unknown association?

We report two cases of siblings presenting coexisting non-radiographic axial spondyloartrhritis and joint hypermobility syndrome, complaining of back pain with morning stiffness, enthesitis, peripheral arthralgia, high erythrocyte sedimentation rate and C-reactive protein level and positive HLA-B27. The association of these two conditions is rare, but especially interesting in view of their contrasting features, one causing axial skeleton stiffness, the other a wider range of peripheral joint movements. Coexistence of these two opposite disorders causes confusion in diagnosis and management, resulting in lower quality of life for patients, as they are in pain from the early stages. Therefore, this association is suspected in young individuals with back pain and physical exam findings of peripheral joint hypermobility and axial skeleton loss of mobility.

HIV drug resistance levels in adults failing first-line antiretroviral therapy in an urban and a rural setting in South Africa.

OBJECTIVES: Urban and rural HIV treatment programmes face different challenges in the long-term management of patients. There are few studies comparing drug resistance profiles in patients accessing treatment through these programmes. The aim of this study was to perform such a comparison. METHODS: HIV drug resistance data and associated treatment and monitoring information for adult patients failing first-line therapy in an urban and a rural programme were collected. Data were curated and managed in SATuRN RegaDB before statistical analysis using Microsoft Excel 2013 and stata Ver14, in which clinical parameters, resistance profiles and predicted treatment responses were compared. RESULTS: Data for 595 patients were analysed: 492 patients from a rural setting and 103 patients from an urban setting. The urban group had lower CD4 counts at treatment initiation than the rural group (98 vs. 126 cells/µL, respectively; P = 0.05), had more viral load measurements performed per year (median 3 vs. 1.4, respectively; P < 0.01) and were more likely to have no drug resistance mutations detected (35.9% vs. 11.2%, respectively; P < 0.01). Patients in the rural group were more likely to have been on first-line treatment for a longer period, to have failed for longer, and to have thymidine analogue mutations. Notwithstanding these differences, the two groups had comparable predicted responses to the standard second-line regimen, based on the genotypic susceptibility score. Mutations accumulated in a sigmoidal fashion over failure duration. CONCLUSIONS: The frequency and patterns of drug resistance, as well the intensity of virological monitoring, in adults with first-line therapy failure differed between the urban and rural sites. Despite these differences, based on the genotypic susceptibility scores, the majority of patients across the two sites would be expected to respond well to the standard second-line regimen.

Sensitivity and specificity of real-time PCR and bacteriological culture for francisellosis in farm-raised Nile tilapia (Oreochromis niloticus L.).

Despite the worldwide occurrence of Francisella noatunensis subsp. orientalis (Fno) infection in farmed tilapia, sensitivity and specificity estimates of commonly used diagnostic tests have not been reported. This study aimed to estimate the sensitivity and specificity of bacteriological culture and qPCR to detect Fno infection. We tested 559 fish, sampled from four farms with different epidemiological scenarios: (i) healthy fish in a hatchery free of Fno; (ii) targeted sampling of diseased fish with suggestive external clinical signs of francisellosis during an outbreak; (iii) convenience sampling of diseased and clinically healthy fish during an outbreak; and (iv) sampling of healthy fish in a cage farm without a history of outbreaks, but with francisellosis reported in other farms in the same reservoir. The qPCR had higher median sensitivity (range, 48.8-99.5%) than culture (range, 1.6-74.4%). Culture had a substantially lower median sensitivity (1.6%) than qPCR (48.8%) to detect Fno in carrier tilapia (farm 4). Median specificity estimates for both tests were >99.2%. The qPCR is the superior test for use in surveillance and monitoring programmes for francisellosis in farmed Nile tilapia, but both tests have high sensitivity and specificity which make them fit for use in the diagnosis of Fno outbreaks.

Prevalence and factors associated with oral potentially malignant disorders in Brazil's rural workers.

OBJECTIVES: To determine the prevalence of oral potentially malignant disorders (OPMDs) in a population of rural workers in the northeast of Brazil and to investigate the association with sociodemographic, occupational, and health factors. METHODS: A total of 1385 workers answered a validated questionnaire and were examined by calibrated dentists. A descriptive analysis, chi-square homogeneity test, and binary logistic regression were performed. RESULTS: The prevalence of OPMDs was 29.6%. Actinic cheilitis was the most predominant (28.4%), followed by leukoplakia (2.3%) and erythroplakia (0.3%). Gender, type of skin, and time exposed to the sun explained the presence of OPMD (P < 0.0001). The study found increased prevalence, especially for males over the age of 60 years and being exposed to the sun for more than 45 years. CONCLUSION: Rural workers showed high vulnerability to the presence of OPMDs, as estimated prevalence exhibited was high.

Ultrasonography as a complementary exam in the diagnosis of oral arteriovenous malformation.

The Doppler ultrasonography (DU) in cases of arteriovenous malformations (AVMs) is not widely use by dentists and there are a lack of information on the topic in the literature. AVM is common in the region of the head and neck and are commonly confused with hemangiomas (congenital). Appropriate classification is essential for therapeutic decision. The diferential diagnosis is based on clinical history, diascopy, and, if necessary, diagnostic imaging. This article present two cases of oral AVM in which DU was crucial in detecting a venous and/or arterial component in purplish lesions in the tongue and buccal mucosa, with positive diascopy. In our cases, after DU, we found a predominance of blood component within the lesion and therefore both patients were referred to the head and neck surgeon for surgical removal of the lesion. Only in the presence of a venous component does outpatient treatment become feasible. Given the predominance of the arterial component, outpatient procedures are contraindicated. Therefore DU is an important supplementary test, being of great importance in the clinical decision and treatment plan for oral AVMs and should become a routine part of the dentist front of vascular lesions of medium to large size.

Thermophilic fungi as new sources for production of cellulases and xylanases with potential use in sugarcane bagasse saccharification.

AIMS: To obtain new cellulases and xylanases from thermophilic fungi; evaluate their potential for sugarcane bagasse saccharification. METHODS AND RESULTS: Thirty-two heat-tolerant fungi were isolated from the environment, identified (morphological/molecular tools) and the production of the enzymes was evaluated by solid state fermentation using lignocellulosic materials as substrates. Myceliophthora thermophila JCP 1-4 was the best producer of endoglucanase (357·51 U g(-1) ), ß-glucosidase (45·42 U g(-1) ), xylanase (931·11 U g(-1) ) and avicelase (3·58 U g(-1) ). These enzymes were most active at 55-70°C and stable at 30-60°C. Using crude enzymatic extract from M. thermophila JCP 1-4 to saccharify sugarcane bagasse pretreated with microwaves and glycerol, glucose and xylose yields obtained were 15·6 and 35·13% (2·2 and 1·95 g l(-1) ), respectively. CONCLUSIONS: All isolated fungi have potential to produce the enzymes; M. thermophila JCP 1-4 enzymatic extract have potential to be better explored in saccharification experiments. Pretreatment improved enzymatic saccharification, as sugar yields were much higher than those obtained from in natura bagasse. SIGNIFICANCE AND IMPACT OF THE STUDY: Myceliophthora thermophila JCP 1-4 produces avicelase (not commonly found among fungi; important to hydrolyse crystalline cellulose) and a ß-glucosidase resistant to glucose inhibition, interesting characteristics for saccharification experiments.