Mosaic human preimplantation embryos and their developmental potential in a prospective, non-selection clinical trial.

Chromosome imbalance (aneuploidy) is the major cause of pregnancy loss and congenital disorders in humans. Analyses of small biopsies from human embryos suggest that aneuploidy commonly originates during early divisions, resulting in mosaicism. However, the developmental potential of mosaic embryos remains unclear. We followed the distribution of aneuploid chromosomes across 73 unselected preimplantation embryos and 365 biopsies, sampled from four multifocal trophectoderm (TE) samples and the inner cell mass (ICM). When mosaicism impacted fewer than 50% of cells in one TE biopsy (low-medium mosaicism), only 1% of aneuploidies affected other portions of the embryo. A double-blinded prospective non-selection trial (NCT03673592) showed equivalent live-birth rates and miscarriage rates across 484 euploid, 282 low-grade mosaic, and 131 medium-grade mosaic embryos. No instances of mosaicism or uniparental disomy were detected in the ensuing pregnancies or newborns, and obstetrical and neonatal outcomes were similar between the study groups. Thus, low-medium mosaicism in the trophectoderm mostly arises after TE and ICM differentiation, and such embryos have equivalent developmental potential as fully euploid ones.

Mucosal-associated invariant T cells are functionally impaired in pediatric and young adult patients following allogeneic hematopoietic stem cell transplantation and their recovery correlates with clinical outcomes.

Mucosal-associated invariant T (MAIT) cells are innate-like T-cells implicated in the response to fungal and bacterial infections. Their contribution to restoring T-cell immunity and influencing hematopoietic stem cell transplant (HSCT) outcomes remains poorly understood. We retrospectively studied MAIT-cell recovery in 145 consecutive children and young adults with hematological malignancies undergoing allo-HSCT, between April/2019 and May/2022, from unrelated matched donor (MUD, n=52), with standard graft-versus-host-disease (GvHD) prophylaxis, or HLA-haploidentical (Haplo, n=93) donor after in vitro αßT/CD19-cell depletion, without post-HSCT pharmacological prophylaxis. With a median follow-up of 33 months (12-49), overall survival (OS), disease-free survival (DFS) and non-relapse mortality (NRM) were 79.5%, 72% and 7%, respectively; GvHD-free, Relapse-free Survival (GRFS) was 63%, while cumulative incidence of relapse was 23%. While WWT-cells reconstituted 1-2 years post-HSCT, MAIT-cells showed delayed recovery and prolonged functional impairment, characterized by expression of activation (CD25, CD38), exhaustion (PD1, TIM3) and senescence (CD57) markers, and suboptimal ex vivo response. OS, DFS and NRM were not affected by MAIT-cells. Interestingly, higher MAIT-cells at day+30 correlated with higher incidence of grade II-IV acute GvHD (19% vs 7%, p=0.06). Furthermore, a greater MAIT-cell count tended to be associated with a higher incidence of chronic GvHD (17% vs 6%, p=0.07) resulting in lower GRFS (55% vs 73%, p=0.05). Higher MAIT-cells also correlated with greater cytomegalovirus (CMV) reactivation and lower late blood stream infections (BSI) (44% vs 24%, p=0.02 and 9% vs 18%, p=0.08, respectively). Future studies are needed to confirm the impact of early MAIT-cell recovery on cGvHD, CMV reactivation and late BSI.

Discard or not discard, that is the question: an international survey across 117 embryologists on the clinical management of borderline quality blastocysts.

STUDY QUESTION: Do embryologists from different European countries agree on embryo disposition decisions ('use' or 'discard') about Day 7 (>144 h post-insemination) and/or low-quality blastocysts (LQB;

Interaction of Water and Oxygen Molecules with Phosphorene: An Ab Initio Study.

Phosphorene, the 2D form of black phosphorus, has recently attracted interest for optoelectronic and tribological applications. However, its promising properties are affected by the strong tendency of the layers to oxidize in ambient conditions. A significant effort has been made to identify the role of oxygen and water in the oxidation process. In this work, we introduce a first-principles study of the phosphorene phase diagram and provide a quantitative estimate of the interaction of pristine and fully oxidized phosphorene layers with oxygen and water molecules. Specifically, we study oxidized layers with oxygen coverages of 25% and 50% that keep the typical anisotropic structure of the layers. We found that hydroxilated and hydrogenated phosphorene layers are both energetically unfavorable, leading to structural distortions. We also studied the water physisorption on both pristine and oxidized layers, finding that the adsorption energy gain doubled on the oxidized layers, whereas dissociative chemisorption was always energetically unfavorable. At the same time, further oxidation (i.e., the dissociative chemisorption of O2) was always favorable, even on oxidized layers. Ab initio molecular dynamics simulations of water intercalated between sliding phosphorene layers showed that even under harsh tribological conditions water dissociation was not activated, thus further strengthening the results obtained from our static calculations. Overall, our results provide a quantitative description of the interaction of phosphorene with chemical species that are commonly found in ambient conditions at different concentrations. The phase diagram that we introduced confirms the tendency of phosphorene layers to fully oxidize due to the presence of O2, resulting in a material with improved hydrophilicity, a piece of information that is relevant for the application of phosphorene, e.g., as a solid lubricant. At the same time, the structural deformations found for the H- and OH- terminated layers undermine their electrical, mechanical, and tribological anisotropic properties and, therefore, the usage of phosphorene.

Inter-centre reliability in embryo grading across several IVF clinics is limited: implications for embryo selection.

RESEARCH QUESTION: What is the intra- and inter-centre reliability in embryo grading performed according to the Istanbul Consensus across several IVF clinics? DESIGN: Forty Day 3 embryos and 40 blastocysts were photographed on three focal planes. Senior and junior embryologists from 65 clinics were invited to grade them according to the Istanbul Consensus (Study Phase I). All participants then attended interactive training where a panel of experts graded the same embryos (Study Phase II). Finally, a second set of pictures was sent to both embryologists and experts for a blinded evaluation (Study Phase III). Intra-centre reliability was reported for Study Phase I as Cohen's kappa between senior and junior embryologists; inter-centre reliability was instead calculated between senior/junior embryologists and experts in Study Phase I versus III to outline improvements after training (i.e. upgrade of Cohen's kappa category according to Landis and Koch). RESULTS: Thirty-six embryologists from 18 centres participated (28% participation rate). The intra-centre reliability was (i) substantial (0.63) for blastomere symmetry (range -0.02 to 1.0), (ii) substantial (0.72) for fragmentation (range 0.29-1.0), (iii) substantial (0.66) for blastocyst expansion (range 0.19-1.0), (iv) moderate (0.59) for inner cell mass quality (range 0.07-0.92), (v) moderate (0.56) for trophectoderm quality (range 0.01-0.97). The inter-centre reliability showed an overall improvement from Study Phase I to III, from fair (0.21-0.4) to moderate (0.41-0.6) for all parameters under analysis, except for blastomere fragmentation among senior embryologists, which was already moderate before training. CONCLUSIONS: Intra-centre reliability was generally moderate/substantial, while inter-centre reliability was just fair. The interactive training improved it to moderate, hence this workflow was deemed helpful. The establishment of external quality assessment services (e.g. UK NEQAS) and the avant-garde of artificial intelligence might further improve the reliability of this key practice for embryo selection.

Inconclusive chromosomal assessment after blastocyst biopsy: prevalence, causative factors and outcomes after re-biopsy and re-vitrification. A multicenter experience.

STUDY QUESTION: Can a second round of biopsy, vitrification and chromosomal testing provide a valid diagnosis where the first attempt fails? SUMMARY ANSWER: The risk of inconclusive chromosomal-assessment after trophectoderm biopsy was 2.5% but a further biopsy and vitrification-warming appeared not to impair the competence of euploid blastocysts. WHAT IS KNOWN ALREADY: The increasing implementation of multicell trophectoderm biopsy has significantly reduced the risk of inconclusive diagnosis after preimplantation-genetic-testing (PGT). Yet, few reports have defined the variables that influence the risk of failure or described the technical and clinical outcomes after re-biopsy. STUDY DESIGN, SIZE, DURATION: Retrospective multicenter study involving 8990 blastocyst biopsies conducted between April 2013 and September 2017 at six IVF centers but analyzed at a single genetic laboratory. A total of 206 blastocysts were successfully re-biopsied after warming and re-expansion, then re-vitrified. And 49 of these blastocysts were diagnosed euploid and used in single-embryo-transfers (SETs). Logistic regression analyses were conducted. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 3244 PGT-for-aneuploidies (PGT-A) cycles with a freeze-all approach, vitrification and qPCR-based analysis were performed by 2687 consenting couples. DNA amplification failure (AF) or non-concurrent data resulted in inconclusive diagnoses. In case of DNA amplification, the cellularity of the biopsy was estimated according to a previously validated method. Euploid SETs were performed. Clinical pregnancy, miscarriage, live birth rates (LBR) and perinatal outcomes were monitored. MAIN RESULTS AND THE ROLE OF CHANCE: Overall, 2.5% of trophectoderm biopsies resulted in an inconclusive diagnosis (N = 228/8990). Specifically, 2% (N = 176/8990) resulted in AF and 0.5% (N = 52/8990) in non-concurrent results. The only parameters significantly associated with inconclusive diagnoses were the IVF center and the embryo age (days) at biopsy. Among samples with successful amplification, the number of cells in the biopsy and the day of biopsy were critical to limit non-concurrent results. In total, 213 blastocysts with an inconclusive diagnosis were warmed for re-analysis and the survival rate was 96.7% (N = 206/213). The euploidy rate in blastocysts biopsied twice was 51.9% (N = 107/206) and the euploid embryos were re-vitrified. Overall, 49 euploid embryos were warmed for replacement and all survived. The LBR after SET was 38.8% (N = 19/49). No minor/major obstetrical/perinatal complication was reported. LIMITATIONS, REASONS FOR CAUTION: A single aneuploidy-testing method was adopted in this retrospective analysis. A more powered report of the clinical and obstetrical/perinatal outcomes after re-biopsied and re-vitrified blastocysts euploid SET requires a larger sample size. WIDER IMPLICATIONS OF THE FINDINGS: It is important to re-biopsy and re-vitrify undiagnosed blastocysts since healthy live births can result from them. STUDY FUNDING/COMPETING INTEREST(S): None. TRIAL REGISTRATION NUMBER: None.

Distinct regions of triadin are required for targeting and retention at the junctional domain of the sarcoplasmic reticulum.

Ca2+ release, which is necessary for muscle contraction, occurs at the j-SR (junctional domain of the sarcoplasmic reticulum). It requires the assembly of a large multiprotein complex containing the RyR (ryanodine receptor) and additional proteins, including triadin and calsequestrin. The signals which drive these proteins to the j-SR and how they assemble to form this multiprotein complex are poorly understood. To address aspects of these questions we studied the localization, dynamic properties and molecular interactions of triadin. We identified three regions, named TR1 (targeting region 1), TR2 and TR3, that contribute to the localization of triadin at the j-SR. FRAP experiments showed that triadin is stably associated with the j-SR and that this association is mediated by TR3. Protein pull-down experiments indicated that TR3 contains binding sites for calsequestrin-1 and that triadin clustering can be enhanced by binding to calsequestrin-1. These findings were confirmed by FRET experiments. Interestingly, the stable association of triadin to the j-SR was significantly decreased in myotubes from calsequestrin-1 knockout mice. Taken together, these results identify three regions in triadin that mediate targeting to the j-SR and reveal a role for calsequestrin-1 in promoting the stable association of triadin to the multiprotein complex associated with RyR.

Tribology of 2D black phosphorus - Current state-of-the-art and future potential.

Since the first mechanical exfoliation of graphene in 2004, the interest in 2D materials has significantly risen due to their outstanding property combination. Multiple 2D materials have been synthesized until today, while black phosphorus (BP) resembles one of their latest additions. The unique properties of BP, especially for electronic and optical devices (i.e., high carrier mobility and electrical conduction, field-effect transistor, layer-dependent bandgap, anisotropic transport), have gained notable attention. However, its layered structure, similar to those of graphene and MoS2, is also advantageous to optimize the friction and wear performance. Moreover, the strong in-plane covalent bonds and weak interlayer van-der-Waals forces favour the formation of low-friction and wear-resistant films. Although BP holds a great tribological potential, the literature to date on this topic is rather scarce. Therefore, it is a timely moment to holistically summarize the synthesis approaches and properties of BP thus guiding interested researchers to use it in mechanical/tribological applications. The existing state-of-the-art regarding tribological research is critically discussed and compared to other 2D materials thus highlighting existing research gaps and paving the way for future research activities.

Association between oocyte donors' or recipients' body mass index and clinical outcomes after first single blastocyst transfers-the uterus is the most affected.

OBJECTIVE: To assess whether high body mass index (BMI) in either oocyte donors or recipients is associated with poorer outcomes after the first single blastocyst transfer. DESIGN: Retrospective study including 1,394 first blastocyst single embryo transfers (SETs) conducted by 1,394 recipients during oocyte donation cycles with the gametes retrieved from 1,394 women (January 2019-July 2021). Four BMI clusters were defined for both donors and recipients (underweight: <18.5 kg; normal weight: 18.5-24.9 kg; overweight: 25-29.9 kg; and obese: ≥30 kg). SETTING: Network of private IVF centers. PATIENTS: A total of 1,394 recipients aged 42.4 ± 4.0 and with a BMI of 23.2 ± 3.8 kg/m2, and 1,394 donors aged 26.1 ± 4.2 and with a BMI of 21.9 ± 2.5 kg/m2. INTERVENTION: All oocytes were vitrified at 2 egg banks and warmed at 8 in vitro fertilization clinics that were part of the same network. Intracytoplasmic sperm injection, blastocyst culture, and either fresh or vitrified-warmed SETs were conducted. Putative confounders were investigated, and the data were adjusted through regression analyses. MAIN OUTCOME MEASURES: The primary outcome was the live birth rate (LBR) per SET according to donors' and/or recipients' BMI. The main secondary outcome was the miscarriage rate (<22 gestational weeks) per clinical pregnancy. RESULTS: The LBR per blastocyst SET showed no significant association with donors' BMI. Regarding recipients' BMI, instead, the multivariate odds ratio was significant in obese vs. normal-weight recipients (0.58, 95% confidence interval, 0.37-0.91). The miscarriage rate per clinical pregnancy was also significantly associated with recipients' obesity, with a multivariate odds ratio of 2.31 (95% confidence interval, 1.18-4.51) vs. normal-weight patients. A generalized additive model method was used to represent the relationship between predicted LBR or miscarriage rates and donors' or recipients' BMI; it pictured a scenario where the former outcome moderately but continuously decreases with increasing recipients' BMI to then sharply decline in the BMI range of 25-35 kg/m2. The miscarriage rate, instead, increases almost linearly with respect to both donors' and recipients' increasing BMI. CONCLUSION: Obesity mostly affects the uterus, especially because of higher miscarriage rates. Yet, poorer outcomes can be appreciated already with a BMI of 25 kg/m2 in both oocyte donors and recipients. Finer markers of nutritional homeostasis are therefore desirable; recipients should be counseled about poorer expected outcomes in cases of overweight and obesity; and oocyte banks should avoid assigning oocytes from overweight donors to overweight and obese recipients.

Effect of vacancies and edges in promoting water chemisorption on titanium-based MXenes.

The functionality of two-dimensional (2D) transition metal carbides and nitrides (MXenes) in technological applications greatly depends on their wettability. For instance, MXenes' layer stability against degradative oxidation is notably reduced when stored in aqueous solutions, leading to the transformation into oxides. In this work, we study water adsorption on Ti-based MXenes by ab initio calculations. The energy gains for the molecular adsorption on Tin+1XnT2 is evaluated as a function of the termination (T = F, O, OH, mixture), the carbon/nitrogen ratio (X = C, N), the layer thickness (n) and water coverage. MXenes' hydrophilicity tends to increase due to the presence of defects as vacancies and flake edges. We demonstrate that physical adsorption occurs through hydrogen bonding on both defect-free layers and layers containing C/N or Ti atomic vacancies, with -OH terminations providing the strongest interactions (0.40-0.65 eV). In contrast, strong water chemisorption is observed on surfaces with a single termination vacancy (0.60-1.20 eV), edges (0.75-0.85 eV), and clusters of defects (1.00-1.80 eV). We verified that the presence of undercoordinated Ti atoms on the surface is the key factor in promoting H2O chemisorption, i.e., the degradative oxidation.

The role of the thymus in allogeneic bone marrow transplantation and the recovery of the peripheral T-cell compartment.

As the thymus represents the primary site of T-cell development, optimal thymic function is of paramount importance for the successful reconstitution of the adaptive immunity after allogeneic hematopoietic stem cell transplantation. Thymus involutes as part of the aging process and several factors, including previous chemotherapy treatments, conditioning regimen used in preparation to the allograft, occurrence of graft-versus-host disease, and steroid therapy that impair the integrity of the thymus, thus affecting its role in supporting T-cell neogenesis. Although the pathways governing its regeneration are still poorly understood, the thymus has a remarkable capacity to recover its function after damage. Measurement of both recent thymic emigrants and T-cell receptor excision circles is valuable tools to assess thymic output and gain insights on its function. In this review, we will extensively discuss available data on factors regulating thymic function after allogeneic hematopoietic stem cell transplantation, as well as the strategies and therapeutic approaches under investigation to promote thymic reconstitution and accelerate immune recovery in transplanted patients, including the use of cytokines, sex-steroid ablation, precursor T-cells, and thymus bioengineering. Although none of them is routinely used in the clinic, these approaches have the potential to enhance thymic function and immune recovery, not only in patients given an allograft but also in other conditions characterized by immune deficiencies related to a defective function of the thymus.

Identification and developmental expression of Xenopus hmga2beta.

HMGA proteins are "architectural modifiers" of the chromatin, characterized by three conserved "AT-hook" motifs, with which they bind AT-rich regions of the DNA, to assist in gene transcription. We report the identification and developmental expression of Xenopus laevis hmga2beta (Xlhmga2beta). We provide evidence of two forms of hmga2 (Xlhmga2alpha and Xlhmga2beta) and of a splicing variant for Xlhmga2beta with an additional AT-hook. By comparing X. laevis and X. tropicalis hmga2 DNA sequences to those of other organisms we show a high conservation of the Xlhmga2beta variant. By RT-PCR, Xlhmga2beta transcripts are first detected before the midblastula transition (MBT), and then become more abundant. By in situ hybridization, localized transcripts are first detected at neurula stages, in the presumptive central nervous system (CNS). At tailbud and tadpole stages, Xlhmga2beta mRNA is detected in the CNS, in the otic vesicles, in neural crest cell derivatives, in the notochord, and in the medio-lateral mesoderm.