Effect of bariatric surgery on maternal cardiovascular system.

OBJECTIVE: Bariatric surgery is a successful treatment for sustainable weight loss and has been associated with improvement in cardiovascular function. Pregnancy after bariatric surgery is becoming increasingly common; however, little is known about the maternal cardiovascular system postsurgery. The aim of this study was to investigate maternal cardiovascular adaptation to pregnancy in women with previous bariatric surgery, compared with that in women with no history of weight-loss surgery and an early-pregnancy body mass index (BMI) similar to the presurgery BMI of the postbariatric women. METHODS: This was a prospective, observational, longitudinal study conducted from April 2018 to June 2020 including 30 pregnant women who had undergone bariatric surgery and 30 who had not, matched for presurgery BMI. Participants were seen at three timepoints during pregnancy: 12-14, 20-24 and 30-32 weeks' gestation. At all visits, maternal blood pressure (BP) was measured and cardiac geometry and function were assessed using two-dimensional (2D) transthoracic echocardiography. On a subset of patients (15 in each group), 2D speckle tracking was performed to assess global longitudinal and circumferential strain. Offline analysis was performed, and multilevel linear mixed-effects models were used for all comparisons. RESULTS: Compared with the no-surgery group, and across all trimesters, pregnant women with previous bariatric surgery had lower BP, heart rate and cardiac output and higher peripheral vascular resistance (P < 0.01 for all). Similarly, the postbariatric group demonstrated more favorable cardiac geometry and diastolic indices, including lower left ventricular mass, left atrial volume and relative wall thickness, together with higher E-wave/A-wave flow velocity across the mitral valve and higher mitral velocity (E') at the lateral and medial annulus on tissue Doppler imaging (P < 0.01 for all). There was no difference in ejection fraction, although global longitudinal strain was lower in postbariatric women (P < 0.01), indicating better systolic function. CONCLUSION: Our findings indicate better maternal cardiovascular adaptation in women with previous bariatric surgery compared with presurgery BMI-matched pregnant women with no history of weight-loss surgery. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Low frequency of TERT promoter mutations in a series of well-differentiated follicular-patterned thyroid neoplasms.

The diagnostic and clinical approaches to follicular-patterned thyroid neoplasms often create dilemmas for pathologist and clinicians. The molecular analysis of these tumors could be a useful tool to overcome diagnostic limitations. The most frequent molecular alterations are point mutations of RAS family genes. Nevertheless, other molecular markers should be taken into account for their prognostic role, as BRAF mutations and the recently described telomerase reverse transcriptase (TERT) promoter mutation. We investigated the prevalence and the possible role of TERT promoter, BRAF, and RAS mutations in a series of low-risk well-differentiated follicular-patterned thyroid neoplasms. We evaluated 60 follicular adenomas (FA), 29 minimally invasive follicular carcinomas (MIFTC), 82 papillary carcinomas, follicular variant (FVPTC), and 16 noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFT-P) for the molecular status of BRAF, H-, N-, K-RAS, and TERT and correlated it with clinic-pathological parameters of tumors. Fifty-seven (30.5%) follicular neoplasms were mutated. In particular, we found 44 RAS mutated neoplasms (23.5%), specifically three FAs, 29 FVPTCs, five NIFT-Ps, and seven FTCs. BRAF mutations were found in ten FVPTCs. Finally, TERT promoter mutations were observed in three FVPTCs and three FTCs; three of them harbored also N-RAS mutations. We confirmed the absence of TERT promoter mutations in benign follicular neoplasms and found a low frequency of TERT promoter mutations in our selected cohort of low-risk follicular-patterned malignancies, speculating their role in the progression and de-differentiation of thyroid cancer.

Calcium oxalate crystal production and density at different phenological stages of soybean plants (Glycine max L.) from the southeast of the Pampean Plain, Argentina.

Glycine max L. (soybean) is one of the major crops of the world. Although the process of biomineralisation has been reported in some organs of soybean, we now report the description and quantification of calcium oxalate crystals in vegetative and reproductive organs of soybean during its life cycle, as they act as an important source of calcium to the soil, once the harvesting is finished. Through diaphanisation, cross-sectioning, optical and scanning electron microscopy analysis of the organs, morphology, size and location of the crystals were identified. In addition, crystal density (n° crystals·mm-2 ) and the input of crystals to soil (n° crystals·ha-1 ) were calculated. Soybean produced prismatic calcium oxalate crystals in vegetative and reproductive organs, generally associated with vascular bundles, resulting in a potencial transfer to the soil of 81.4 x 107 crystals·ha-1 throughout its life cycle. Pods were the organs with higher calcium oxalate crystal production (1112.7 ± 384.6 crystals·mm-2 ), but with the smaller size (12.3 ± 2.1 µm long). However, cotyledons were the organs that produce the larger crystals (21.3 ± 3.5 µm long), but in lesser amounts (150.9 ± 64.4 crystals·mm-2 ). In leaves, although crystal size did not differ from vegetative to reproductive stage (14.5 ± 4.2 and 14.5 ± 4 µm in length, respectively), the crystal density increased (293.2 and 409 crystals·mm-2 , respectively). These results will contribute to knowledge of the amount of calcium oxalate crystals involved in the process of Ca recycling through cultivated vegetation in fields from humid plains at medium latitudes, which therefore have biological, botanical, biogeochemical and pedological relevance.

Early silicification of leaves and roots of seedlings of a panicoid grass grown under different conditions: anatomical relations and structural role.

Grasses accumulate high amounts of silica deposits in tissues of all their organs, especially at mature stage. However, when and under which conditions do grass seedlings begin to produce these silica deposits and their relation with anatomy and development is little known. Here we investigated the silicification process in the first leaves and roots of seedlings of Bothriochloa laguroides grown in different substrate and Si treatments. The distribution and content of silica deposits in the organs of the seedlings grown under different conditions were analyzed through staining techniques and SEM-EDAX analyses. Leaf silica deposits were accumulated 3-4 days after the first leaf emergence, also under low silica solution (0.17-0.2 mM). Their location was mainly restricted to short costal cells from basal sectors, and scarcely in trichomes and xylem at tips. Silica content in leaves increased with the age of the seedlings. Roots presented dome-shaped silica aggregates, between 4-12 µm of diameter, located in the inner tangential wall of endodermal cells and similar to those produced at maturity. Silicification begins early in the first photosynthetic leaf, and silica distribution is opposite to that found in mature plants, mainly restricted to basal sectors, probably acting as a reinforcing element. The fast incorporation of solid amorphous silica in leaves and roots, may be useful for farm applications in species that are Si-fertilized.

BRAF and RAS mutations as prognostic factors in metastatic colorectal cancer patients undergoing liver resection.

BACKGROUND: Despite major advances in the management of metastatic colorectal cancer (mCRC) with liver-only involvement, relapse rates are high and reliable prognostic markers are needed. METHODS: To assess the prognostic impact of BRAF and RAS mutations in a large series of liver-resected patients, medical records of 3024 mCRC patients were reviewed. Eligible cases undergoing potentially curative liver resection were selected. BRAF and RAS mutational status was tested on primary and/or metastases by means of pyrosequencing and mass spectrometry genotyping assay. Primary endpoint was relapse-free survival (RFS). RESULTS: In the final study population (N=309) BRAF mutant, RAS mutant and all wild-type (wt) patients were 12(4%), 160(52%) and 137(44%), respectively. Median RFS was 5.7, 11.0 and 14.4 months respectively and differed significantly (Log-rank, P=0.043). At multivariate analyses, BRAF mutant had a higher risk of relapse in comparison to all wt (multivariate hazard ratio (HR)=2.31; 95% CI, 1.09-4.87; P=0.029) and to RAS mutant (multivariate HR=2.06; 95% CI, 1.02-4.14; P=0.044). Similar results were obtained in terms of overall survival. Compared with all wt patients, RAS mutant showed a higher risk of death (HR=1.47; 95% CI, 1.05-2.07; P=0.025), but such effect was lost at multivariate analyses. CONCLUSIONS: BRAF mutation is associated with an extremely poor median RFS after liver resection and with higher probability of relapse and death. Knowledge of BRAF mutational status may optimise clinical decision making in mCRC patients potentially candidate to hepatic surgery. RAS status as useful marker in this setting might require further studies.

Physics and chemistry of antimicrobial behavior of ion-exchanged silver in glass.

The results of a comprehensive study involving the antimicrobial activity in a silver ion-exchanged glass are presented. The study includes the glass composition, the method of incorporating silver into the glass, the effective concentration of the silver available at the glass surface, and the effect of the ambient environment. A quantitative kinetic model that includes the above factors in predicting the antimicrobial activity is proposed. Finally, experimental data demonstrating antibacterial activity against Staphylococcus aureus with correlation to the predicted model is shown.

Trace metal pyritization variability in response to mangrove soil aerobic and anaerobic oxidation processes.

The degree of iron pyritization (DOP) and degree of trace metal pyritization (DTMP) were evaluated in mangrove soil profiles from an estuarine area located in Rio de Janeiro (SE Brazil). The soil pH was negatively correlated with redox potential (Eh) and positively correlated with DOP and DTMP of some elements (Mn, Cu and Pb), suggesting that pyrite oxidation generated acidity and can affect the importance of pyrite as a trace metal-binding phase, mainly in response to spatial variability in tidal flooding. Besides these aerobic oxidation effects, results from a sequential extraction analyses of reactive phases evidenced that Mn oxidized phase consumption in reaction with pyrite can be also important to determine the pyritization of trace elements. Cumulative effects of these aerobic and anaerobic oxidation processes were evidenced as factors affecting the capacity of mangrove soils to act as a sink for trace metals through pyritization processes.

Follicular-derived neoplasms: morphometric and genetic differences.

BACKGROUND: The distinction between follicular adenomas (FAs) and well differentiated follicular and papillary carcinomas is often a demanding task and sometimes only intuitive. AIM: We report an histomorphological evaluation of follicular neoplasms [FAs, follicular carcinomas (FCs), and follicular variant of papillary carcinomas (FVPTCs)], supported by a qualitative and quantitative image analysis and by a molecular characterization. MATERIAL AND METHODS: Tumor fibrosis and haemorrhage, neoplastic capsule thickness, follicle diameter, number of neoplastic cells, nuclear diameter of neoplastic cells, vessels density, vessels area and intratumoral distribution were evaluated. Ras and BRAF mutations, RET/PTC1, RET/PTC3, and PAX8/PPARγ rearrangements were analyzed. Correlations with clinico-pathological features have been studied. RESULTS: We found that FAs had a more extensive intratumoral haemorrhage, while malignant neoplasms were characterized by an evident fibrosis, higher cellularity and larger size. FVPTCs had higher nuclear diameter; cells count was higher in the minimally invasive follicular thyroid carcinomas, as well as a thickener neoplastic capsule. The CD34 stain showed a higher microvessel density in the FVPTCs group. A higher peripheral vessels distribution was observed only in malignant neoplasms. We observed overall Ras mutations in 2.4% of adenomas, in 41.5% of FVPTCs, and in 44.8% of FCs. It is outstanding that there is a marked difference in the Ras mutation distribution between the benign and malignant tumors in our series. CONCLUSIONS: We found that genotyping of Ras gene family together with an accurate analysis of selected morphological features could help in the differential diagnosis of follicular-derived thyroid neoplasms.

Nickel-doped nanocrystalline glass-ceramic fiber.

The spectroscopic properties of Ni(2+)- doped nanocrystalline glass-ceramic fibers are reported. The cerammed fibers show strong fluorescence with peak wavelength at 1250 nm, 3-dB bandwidth at ~250nm, measured lifetimes at >1ms, and low-fluorescence saturation powers (~35mW) for 980-nm diode pumping. Current diode-pumped output powers are ~100microW .

Fabrication and analysis of a directional coupler written in glass by nanojoule femtosecond laser pulses.

A directional coupler written in a glass sample by the focused 400-nm output from a 25-fs oscillator is reported. The coupler is single mode; the splitting ratio is 1.9 dB at 633 nm. A refractive-index profile of the waveguide with a magnitude of Dn = 4.5 x 10(-3) was retrieved from a near-field mode pattern.

Efficient neodymium-doped glass-ceramic fiber laser and amplifier.

We report an efficient glass-ceramic fiber laser and show that its slope efficiency (~30%) is not compromised by the presence of Nd-doped fluoride crystals embedded within the core of the single-mode optical fiber. In contrast, the spectroscopy (fluorescence and gain spectrum) of the Nd(3+) ions is dramatically changed by the ceramming process, an indication of strong partitioning of the rare-earth ions into the CdF(2):PbF(2):YF(3) crystal environment. The enormous potential for a new range of optical devices based on transparent glass-ceramic materials is highlighted.

Transient absorption in excimer-exposed silica.

The transient absorption produced in high-purity fused silica by exposure to a 193-nm excimer laser is investigated as a function of exposure, dissolved molecular hydrogen content, and hydrogen-related processing. Long-term recovery of transmittance was found to correlate with the dissolved molecular hydrogen concentration, whereas short-term fade was due to geminate recombination of an E? center with an H radical. The redarkening process was shown to be the result of photolysis of SiH, which regenerates color centers. When the silica was processed in a hydrogen atmosphere at high temperature and subsequently exposed at 193 nm, the glass was found to produce an absorption spike, a fast, recoverable decrease in transmittance. The origin of the spike was linked to the creation of a precursor produced in the thermal reaction of silica with hydrogen. The precursor can be identified by its signal in the Raman spectrum. It is suggested that the precursor has absorption at 193 nm.

Measurement of the nonlinear optical response of optical fiber materials by use of spectrally resolved two-beam coupling.

We present measurements of the femtosecond nonlinear response of fiber waveguide materials, obtained with spectrally resolved two-beam coupling. This simple but sensitive technique provides all the parameters that characterize the third-order nonlinear optical response, including the dynamics. Measurements are made with nanojoule-energy pulses from a mode-locked Ti:sapphire laser and a few millimeters of waveguide preform, without the need for drawing fiber.

Bragg gratings in defect-free germanium-doped optical fibers.

Bragg gratings have been written in germanium-doped optical fibers that have been treated to remove the UV absorption bands associated with oxygen-deficient defects. When one is using high-intensity 193-nm light from an ArF excimer laser to fabricate the gratings, the refractive index increases and the grating transmission spectra are similar to those obtained in standard (untreated) fiber.

Infrared photosensitivity in silica glasses exposed to femtosecond laser pulses.

We investigate the use of infrared femtosecond laser pulses to induce highly localized refractive-index changes in fused-silica glasses. We characterize the magnitude of the change as a function of exposure and measure index changes as large as 3x10(-3) and 5x10(-3) in pure fused silica and boron-doped silica, respectively. The potential of this technique for writing three-dimensional photonic structures in bulk glasses is demonstrated by the fabrication of a Y coupler within a sample of pure fused silica.

Excimer-laser-induced densification in binary silica glasses.

We report that the rate of excimer-laser-induced densification is a strong function of composition in the binary metal-oxide-silica system. The pulsed excimer-laser-induced densification rate is shown to increase with metal-oxide content. A good correlation was found between the densification rate and the relative softness of the glass, as indicated by the annealing temperature. The densification rate for all the glasses was also found to be a strong function of the excimer-laser wavelength in the order 157nm>193nm >248nm .

Photorefraction in lead tin-fluorophosphate glasses.

Permanent grating patterns have been written directly in lead-tin-fluorophosphate glasses by use of UV radiation. The effect of photorefraction is studied in different tin-fluorophosphate compositions. Recorded gratings are found to be volume rather than surface elements. The induced index changes are comparable with those seen in GeO(2)- SiO(2) glasses.

193-nm excimer-laser-induced densification of fused silica.

We report the densification of fused silica as a function of exposure to pulsed 193-nm excimer-laser irradiation. Defining a dose as the number of pulses N times the square of fluence I per pulse, we find that densification follows a universal function of dose, a x (NI(2))(b), where a and b can vary somewhat according to glass preparation. Densification is measured with interferometry and birefringence, interpreted with a finiteelement elastic model. Wave-front distortion for a typical photolithographic lens element in typical use conditions is described.

Imaging and radiometric properties of microlens arrays.

The imaging and radiometric properties of erect lens arrays made up of small biconvex microlenses are derived from a ray analysis. The lens arrays provide erect, unit magnification images. The relationship between the radii of curvature, the lens thickness, and the one-to-one conjugate distance is derived for both the single-layer case and a double-layer structure, which contains field lenses. Radiometric properties of the microlens and the array are derived for both structures. The results are compared to experimentally measured values obtained from arrays fabricated by a photothermal process.

Microlens arrays produced by a photolytic technique.

Spherical microlens arrays are produced directly from glass by a photothermal process. The method, performance of lenses, and applications are discussed.