Monochorionic triplet pregnancy complicated by conjoined twins and early twin-twin transfusion syndrome.

BACKGROUND: The condition of monozygotic, monochorionic triplet fetuses with a pair of conjoined twins is extremely rare (close to one in a million births), presents challenges in its management, and with poor prognosis. CASE REPORT: We report a case of monochorionic diamniotic triplet pregnancy, ultrasound at 14 weeks shows a pair of conjoined thoracopagus fetuses, sharing heart, liver, and umbilical cord, in addition to omphalocele. The third fetus, without malformations, presents signs of early heart failure compatible with twin-to-twin transfusion syndrome. It was decided to carry out expectant management where at 18 weeks, intrauterine death of the three fetuses occurs. An abortion is performed by hysterotomy. CONCLUSIONS: The treatment in these cases is discussed, three management options have been proposed: expectant management, selective reduction of the conjoined fetuses, or termination of the pregnancy. A review of the literature found only 12 cases with this combination of pathologies, in which only 3 normal fetuses (25%) survived and none of the conjoined twins survived. To our knowledge, this case is the first of a monochorionic triplet pregnancy with conjoined fetuses complicated with early twin-to-twin transfusion.

Role of Triplet States in the Photolysis of Proteogenic Amino Acids.

This investigation delves into the UV photodissociation of pivotal amino acids (Alanine, Glycine, Leucine, Proline, and Serine) at 213 nm, providing insights into triplet-state deactivation pathways. Utilizing a comprehensive approach involving time-dependent density functional calculations (TD-DFT), multi-configurational methods, and ab-initio molecular dynamics (AIMD) simulations, we scrutinize the excited electronic states (T1 , T2 , and S1 ) subsequent to 213 nm excitation. Our findings demonstrate that α-carbonyl C-C bond-breaking in triplet states exhibits markedly lower barriers than in singlet states (below 5.0 kcal mol-1 ). AIMD simulations corroborate the potential involvement of triplet states in amino acid fragmentation, underscoring the significance of accounting for these states in photochemistry. Chemical bonding analyses unveil distinctive patterns for S1 and T1 states, with the asymmetric redistribution of electron density characterizing the C-C breaking in triplet states, in contrast to the symmetric breaking observed in singlet states. This research complements recent experimental discoveries, enhancing our comprehension of amino acid reactions in the interstellar medium.

The copious photochemistry of 2,6-diaminopurine: Luminescence, triplet population, and ground state recovery.

9H- and 7H-2,6-Diaminopurine (26DAP) photoinduced events in vacuum were studied at the MS-CASPT2/cc-pVDZ level of theory. The S1 1 (ππ* La ) state is initially populated evolving barrierless towards its minimum energy structure, from where two photochemical events can take place in both tautomers. The first is the return of the electronic population to the ground state via the C6 conical intersection (CI-C6). The second involves an internal conversion to the ground through the C2 conical intersection (CI-C2). According to our geodesic interpolated paths connecting the critical structures, the second route is less favorable in both tautomers, due to the presence of high energy barriers. Our calculations suggest a competition between fluorescence and ultrafast relaxation to the electronic ground state via internal conversion process. Based on our calculated potential energy surfaces and experimental excited state lifetimes from the literature, we can infer that the 7H- must have a greater fluorescence yield than the 9H-tautomer. We also explored the triplet state population mechanisms on the 7H-26DAP to understand their long-lived components observed experimentally.

Two-Stage Pedestrian Detection Model Using a New Classification Head for Domain Generalization.

Pedestrian detection based on deep learning methods have reached great success in the past few years with several possible real-world applications including autonomous driving, robotic navigation, and video surveillance. In this work, a new neural network two-stage pedestrian detector with a new custom classification head, adding the triplet loss function to the standard bounding box regression and classification losses, is presented. This aims to improve the domain generalization capabilities of existing pedestrian detectors, by explicitly maximizing inter-class distance and minimizing intra-class distance. Triplet loss is applied to the features generated by the region proposal network, aimed at clustering together pedestrian samples in the features space. We used Faster R-CNN and Cascade R-CNN with the HRNet backbone pre-trained on ImageNet, changing the standard classification head for Faster R-CNN, and changing one of the three heads for Cascade R-CNN. The best results were obtained using a progressive training pipeline, starting from a dataset that is further away from the target domain, and progressively fine-tuning on datasets closer to the target domain. We obtained state-of-the-art results, MR-2 of 9.9, 11.0, and 36.2 for the reasonable, small, and heavy subsets on the CityPersons benchmark with outstanding performance on the heavy subset, the most difficult one.

Introduction to Python Dynamic Diffraction Toolkit (PyDDT): structural refinement of single crystals via X-ray phase measurements.

PyDDT is a free Python package of computer codes for exploiting X-ray dynamic multiple diffraction in single crystals. A wide range of tools are available for evaluating the usefulness of the method, planning feasible experiments, extracting phase information from experimental data and further improving model structures of known materials. Graphical tools are also useful in analytical methodologies related to the three-dimensional aspect of multiple diffraction. For general X-ray users, the PyDDT tutorials provide the insight needed to understand the principles of phase measurements and other related methodologies. Key points behind structure refinement using the current approach are presented, and the main features of PyDDT are illustrated for amino acid and filled skutterudite single crystals.

Evolution of the triplet BRCT domain.

Organisms have evolved a complex system, called the DNA damage response (DDR), which maintains genome integrity. The DDR is responsible for identifying and repairing a variety of lesions and alterations in DNA. DDR proteins coordinate DNA damage detection, cell cycle arrest, and repair, with many of these events regulated by protein phosphorylation. In the human proteome, 23 proteins contain the BRCT (BRCA1 C-Terminus domain) domain, a modular signaling domain that can bind phosphopeptides and mediate protein-protein interactions. BRCTs can be found as functional single units, tandem (tBRCT), triplet (tpBRCT), and quartet. Here we examine the evolution of the tpBRCT architecture present in TOPBP1 (DNA topoisomerase II binding protein 1) and ECT2 (epithelial cell transforming 2), and their respective interaction partners RAD9 (Cell cycle checkpoint control protein RAD9) and CYK-4 (Rac GTPase-activating protein 1), with a focus on the conservation of the phosphopeptide-binding residues. The pair TOPBP1-RAD9 arose with the Eukaryotes and ECT2-CYK-4 with the Eumetazoans. Triplet structural and functional characteristics were conserved in almost all organisms. The first unit of the triplet (BRCT0) is different from the other two BRCTs but conserved between orthologs for both TOPBP1 and ECT2. BRCT domain evolution simulations suggest a trend to retain the singlet or towards two or three BRCT copies per protein consistent with functional tBRCT and tpBRCT architectures. Our results shed light on the emergence of the function and architecture of multiple BRCT domain organizations and provide information about the evolution of the BRCT triplet. Knowledge of BRCT domain evolution can improve the understanding of DNA damage response mechanisms and signal transduction in DDR.

Mining reactive triplet carbonyls in biological systems.

Aliphatic triplet carbonyls can be treated as short-lived radicals, since both species share similar reactions such as hydrogen atom abstraction, cyclization, addition, and isomerization. Importantly, enzyme-generated triplet carbonyls excite triplet molecular oxygen to the highly reactive, electrophilic singlet state by resonance energy transfer, which can react with proteins, lipids, and DNA. Carbonyl triplets, singlet oxygen, and radicals are endowed with the potential to trigger both normal and pathological responses. In this paper, we present a short review of easy, fast, and inexpensive preliminary tests for the detection of transient triplet carbonyls in chemical and biological systems. This paper covers direct and indirect methods to look for triplet carbonyls based on their spectral distribution of chemiluminescence, photoproduct analysis, quenching of light emission by conjugated dienes, and enhancement of light emission by the sensitizer 9,10-dibromoanthracence-2-sulfonate ion (DBAS).

Pyrolysis Kinetics of Byrsonima crassifolia Stone as Agro-Industrial Waste through Isoconversional Models.

This study is aimed at the analysis of the pyrolysis kinetics of Nanche stone BSC (Byrsonima crassifolia) as an agro-industrial waste using non-isothermal thermogravimetric experiments by determination of triplet kinetics; apparent activation energy, pre-exponential factor, and reaction model, as well as thermodynamic parameters to gather the required fundamental information for the design, construction, and operation of a pilot-scale reactor for the pyrolysis this lignocellulosic residue. Results indicate a biomass of low moisture and ash content and a high volatile matter content (≥70%), making BCS a potential candidate for obtaining various bioenergy products. Average apparent activation energies obtained from different methods (KAS, FWO and SK) were consistent in value (~123.8 kJ/mol). The pre-exponential factor from the Kissinger method ranged from 105 to 1014 min-1 for the highest pyrolytic activity stage, indicating a high-temperature reactive system. The thermodynamic parameters revealed a small difference between EA and ∆H (5.2 kJ/mol), which favors the pyrolysis reaction and indicates the feasibility of the energetic process. According to the analysis of the reaction models (master plot method), the pyrolytic degradation was dominated by a decreasing reaction order as a function of the degree of conversion. Moreover, BCS has a relatively high calorific value (14.9 MJ/kg) and a relatively low average apparent activation energy (122.7 kJ/mol) from the Starink method, which makes this biomass very suitable to be exploited for value-added energy production.

Multi-conformational Luminescence and Phosphorescence of Few Phenazine 1,2,3-triazole Molecules.

Dropcast films produced from blends solutions of phenazine 1,2,3-triazole molecules in very low concentrations in a 1,3-Bis (N-carbazolyl) benzene (mCP) matrix were investigated at room tem-perature. The mCP acts as an optically inert matrix, having no influence on the emission properties of the guest molecules. Its conductive properties ensure the blend films as completely organic active layers. The fluorescent and phosphorescent emissions of the guest molecules in blue, green, red and also in white are relatively intense, without the need to mix different organic materials. The excitation of the system occurs directly by the incident laser beam on the films. The steady-state spectroscopy for the blue monomer and green dimer singlet fluorescence emissions were investigated. The analysis of their temporal decays was done using a different approach based on the Exponentially Modified Gaussian function. The phosphorescent emissions of the triplet steady-states, in the orange or in the red wavelength regions, were observed to be correlated, respectively, to the formation of guest monomers or to the guest dimers singlet states.

A multitask deep representation for Gleason score classification to support grade annotations.

The Gleason grade system is the main standard to quantify the aggressiveness and progression of prostate cancer. Currently, exists a high disagreement among experts in the diagnosis and stratification of this disease. Deep learning models have emerged as an alternative to classify and support experts automatically. However, these models are limited to learn a rigid stratification rule that can be biased during training to a specific observer. Therefore, this work introduces an embedding representation that integrates an auxiliary task learning to deal with the high inter and intra appearance of the Gleason system. The proposed strategy implements as a main task a triplet loss scheme that builds a feature embedding space with respect to batches of positive and negative histological training patches. As an auxiliary task is added a cross-entropy that helps with inter-class variability of samples while adding robust representations to the main task. The proposed approach shows promising results achieving an average accuracy of 66% and 64%, for two experts without statistical difference. Additionally, reach and average accuracy of 73% in patches where both pathologists are agree, showing the robustness patterns learning from the approach.

New Perspectives of Gene Therapy on Polyglutamine Spinocerebellar Ataxias: From Molecular Targets to Novel Nanovectors.

Seven of the most frequent spinocerebellar ataxias (SCAs) are caused by a pathological expansion of a cytosine, adenine and guanine (CAG) trinucleotide repeat located in exonic regions of unrelated genes, which in turn leads to the synthesis of polyglutamine (polyQ) proteins. PolyQ proteins are prone to aggregate and form intracellular inclusions, which alter diverse cellular pathways, including transcriptional regulation, protein clearance, calcium homeostasis and apoptosis, ultimately leading to neurodegeneration. At present, treatment for SCAs is limited to symptomatic intervention, and there is no therapeutic approach to prevent or reverse disease progression. This review provides a compilation of the experimental advances obtained in cell-based and animal models toward the development of gene therapy strategies against polyQ SCAs, providing a discussion of their potential application in clinical trials. In the second part, we describe the promising potential of nanotechnology developments to treat polyQ SCA diseases. We describe, in detail, how the design of nanoparticle (NP) systems with different physicochemical and functionalization characteristics has been approached, in order to determine their ability to evade the immune system response and to enhance brain delivery of molecular tools. In the final part of this review, the imminent application of NP-based strategies in clinical trials for the treatment of polyQ SCA diseases is discussed.

Photoactivation of Erythrosine in simulated body fluids.

Photodynamic Therapy (PDT) is a powerful technique for the treatment of cancer and non-cancerous diseases. The precise PDT treatment protocol definition must consider the performance difference between in vitroand in vivoapplications. This also occurs in other biological studies, and to partially overcome this difficulty, the simulated body fluids are generally applied as a prior understanding of the particularities of the different systems. However, in PDT these studies are scarce. In this work, we investigated the photoactivation of Erythrosine, a photosensitizer widely used in PDT, in different simulated body fluids. Differences in the photodegradation kinetics, triplet lifetime, and singlet oxygen generation were observed. The results can help to explain and to define PDT application protocols.

Nematic Triphenyltriazine Triesters and the Induction of the Columnar Mesophase by Fluorine Substitution.

Whereas their para homologs are not mesogenic, the disk-shaped triphenyltriazine meta-trialkylesters obtained via trimerization of 3-cyanobenzoic alkylester, which are configurationally more flexible, exhibit a monotropic nematic mesophase. Introduction of fluorine atoms into the alkyl chains or into the phenyl moieties leads to the appearance of an enantiotropic columnar mesophase. If fluorine is introduced both in the chains and in the phenyl moieties, only a monotropic mesophase remains. Fluorination of either the alkyl chains or the aromatic core, but not both, appears thus as a simple means of inducing or stabilizing columnar self-assembly in disk-shaped systems. As the homeotropically alignable columnar mesophase can thus be made to persist at room temperature, as energies higher than 3 eV of the first excited triplet state are computed in agreement with the value reported for the parent arene, and as they are not fluorescent themselves, these compounds are of promise as aligning host matrices for blue-emitting TADF devices with improved light outcoupling. Dilution of a columnar with a nonmesogenic homolog induces the nematic state, indicating that the nanoscopic make-up of both mesophases is closely related.

Distribution of the CAG Triplet Repeat in ATXN1, ATXN3, and CACNA1A Loci in Peruvian Population.

Spinocerebellar ataxia subtypes 1, 3, and 6 (SCA1, MJD/SCA3, and SCA6) are among the most prevalent autosomal dominant cerebellar ataxias worldwide, but their relative frequencies in Peru are low. Frequency of large normal (LN) alleles at spinocerebellar ataxia-causative genes has been proposed to be associated with disease prevalence. To investigate the allelic distribution of the CAG repeat in ATXN1, ATXN3, and CACNA1A genes in a Peruvian mestizo population and examine their association with the relative frequency of SCA1, MJD/SCA3, and SCA6 across populations. We genotyped 213 healthy mestizo individuals from Northern Lima, Peru, for ATXN1, ATXN3, and CACNA1A using polymerase chain reaction (PCR) and polyacrylamide gel electrophoresis (PAGE). We compared the frequency of LN alleles and relative disease frequency between populations. We also tested 40 samples for CAT repeat interruptions within the CAG tract of ATXN1. We found no association between disease frequency and population frequency of LN alleles at ATXN1 and ATXN3. All 40 ATXN1 samples tested for CAT interruptions were positive. Frequency of LN alleles at CACNA1A correlates with SCA6 frequency across several populations, but this effect was largely driven by data from a single population. Low frequency of SCA1 and MJD/SCA3 in Peru is not explained by frequency of LN alleles at ATXN1 and ATXN3, respectively. The observed correlation between CACNA1A LN alleles and SCA6 frequency requires further assessment.

The type specimens of Trichomycterus alternatus (Eigenmann, 1917) and Trichomycterus zonatus (Eigenmann, 1918), with elements for future revisionary work (Teleostei: Siluriformes: Trichomycteridae).

The trichomycterid catfish species Trichomycterus alternatus (Eigenmann, 1917) and Trichomycterus zonatus (Eigenmann, 1918) are reportedly among the most pervasive species in mid- to high-elevation coastal streams of Southeastern Brazil. Despite their apparent abundance and ecological ubiquity, the applicability of their names is still uncertain. Examination of the type material of the two species reveals that part of the confusion stems from a mixing of species in the T. zonatus type series. Other issues relate to reports of character conditions in the respective species that do not actually correspond to the situation in their type specimens. Such situation triggered a long-lasting chain of taxonomic misinterpretations and erroneous identification protocols and traditions so that even the taxonomic distinctiveness of the two species is nebulous. That situation is disentangled in detail on the basis of new information on the holotypes and remaining type specimens of each species by classical and new (stereo triplet radiography) morphology analyses for data acquisition. Results show that the type specimens of T. alternatus and T. zonatus differ pronouncedly in several traits of internal and external morphology and represent markedly distinct taxa. The latter species does not correspond to most identifications in the literature and is, in fact, endemic to the region of its type locality. We also clarify and map the reported localities of the type material and offer comments on the validity of T. alternatus and T. zonatus, along with that of possibly related forms.

Kinetic triplet of Colombian sawmill wastes using thermogravimetric analysis.

The potential of sawmill wastes as a raw material in pyrolysis process is presented in this study. Non-isothermal thermogravimetric analysis (TGA and DTG) and isoconversional methods were employed to determine triplet kinetic (activation energy, reaction model and pre-exponential factor). Through TGA and DTG, the conversion degree is described as a function of temperature for five heating rates (10, 20, 30, 40 and 50 o C/min) and four model-free methods (Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), Friedman, and Vyazovkin) with temperatures ranging from 25 to 1000 ° C were employed. Isoconversional lines were built for every method at different isoconversional degrees α ∈ [ 0,1 ] . The activation energy E was found as a function of α in the interval χ I I = [ 0.2 , 0.7 ] where each isoconversional methods were in agreement and the estimated error was sufficiently small. Findings show the same activation energy profile independently of the isoconversional method. In particular the total variation of E in χ I I was as follows: 209.909-228.238 kJ/mol (FWO); 211.235-229.277 kJ/mol (KAS); 223.050-188.512 kJ/mol (Friedman), and 211.449 kJ/mol-229.512 kJ/mol (Vyazovkin). The reaction model of the process in χ I I matched with a two-dimensional diffusion ( D 2 ) by using a master-plot analysis. The calculated and reported parameters are fundamental information for the pyrolysis reactor design using Sawmill wastes as feedstock.

Persistent Solid-State Phosphorescence and Delayed Fluorescence at Room Temperature by a Twisted Hydrocarbon.

The dehydrating cyclotrimerization of 1-tetralone in the presence of titanium tetrachloride at high temperatures leads to homotruxene, a nonplanar arene in which the twist angles between its three outer benzene rings and the central benzene are stabilized by ethylene bridges. This non-planar configuration allows for pronounced spin-orbit coupling and a high triplet energy, leading to room-temperature phosphorescence in air with a lifetime of 0.38 s and a quantum yield of 5.6 %, clearly visible to the human eye after switching off the excitation. Triplet-triplet annihilation is found to simultaneously lead to a substantial delayed fluorescence, unprecedented from a pure hydrocarbon at ambient conditions, with a lifetime of 0.11 s.

Physiological considerations acting on triplet oxygen for explicit dosimetry in photodynamic therapy.

The aims of this study were to determine the spatial and temporal theoretical distribution of the concentrations of Protoporphyrin IX, 3O2 and doses of 1O2. The type II mechanism and explicit dosimetry in photodynamic therapy were used. Furthermore, the mechanism of respiration and cellular metabolism acting on 3O2 were taken into account. The dermis was considered as an absorbing and a scattering medium. An analytical solution was used for light diffusion in the skin. The photophysical, photochemical and biological effects caused by PDT with the initial irradiances of 20, 60 and 150mW/cm2 were studied for a time of exposure of 20min and a maximum depth of 0.5cm. We found that the initial irradiance triples its value in 0.02cm and that almost 100% of PpIX is part of the dynamics of reactions in photodynamic therapy. Additionally, with about 40µMof 3O2 there is a balance between the consumed and supplied oxygen. Finally, we determined that with 60mW/cm2, the highest dose of 1O2 is obtained.

X-ray dynamical diffraction in amino acid crystals: a step towards improving structural resolution of biological molecules via physical phase measurements.

In this work, experimental and data analysis procedures were developed and applied for studying amino acid crystals by means of X-ray phase measurements. The results clearly demonstrated the sensitivity of invariant triplet phases to electronic charge distribution in d-alanine crystals, providing useful information for molecular dynamics studies of intermolecular forces. The feasibility of using phase measurements to investigate radiation damage mechanisms is also discussed on experimental and theoretical grounds.

Prediction of perinatal mortality in triplet pregnancies.

PURPOSE: To investigate predictors of perinatal mortality in triplet pregnancies. METHODS: Retrospective cohort managed in a tertiary teaching hospital (1998-2012) including all pregnancies with tree live fetuses at the first ultrasound examination, performed after 11 weeks of gestation. Primary end-point was defined as the number of children alive at hospital discharge. Ordinal stepwise regression analysis examined the association with maternal age, parity, pregnancy chorionicity, gestational age at our first ultrasound evaluation, presence of maternal clinical, obstetrical and fetal complications and gestational age at delivery. RESULTS: Sixty-seven triplet pregnancies were first seen at 18.5 ± 6.8 weeks, 33 (49.3 %) were trichorionic, obstetric complications occurred in 34 (50.7 %) and fetal complications were diagnosed in 17 (25.4 %). Perinatal mortality rate was 249 ‰ (95 % CI 189-317) and 138 (73 %) children were discharged alive from hospital (11 pregnancies with no survivors; single and double survival in ten cases each; all children alive in 36). Regression analysis showed that presence of fetal complications (OR 0.10, 95 % CI 0.03-0.36) and gestational age at delivery (OR 1.55, 95 % CI 1.31-1.85) are significant predictors of outcome (p < 0.001). CONCLUSIONS: Perinatal mortality in non-selected triplet pregnancies is high and is related to the presence of fetal complications and gestational age at delivery.