Abstract
STUDY QUESTION
Is the indication for fertility preservation (FP) related to success in IVF cycles after elective-FP (EFP) for age-related fertility decline and FP before cancer treatment ...(Onco-FP)?
SUMMARY ANSWER
Although success rates were lower in cancer patients, there was no statistically significant association between malignant disease and reproductive outcome after correction for age and controlled-ovarian stimulation (COS) regime.
WHAT IS KNOWN ALREADY
FP is increasingly applied in assisted reproduction, but little is known about the outcome of IVF cycles with vitrified oocytes in FP patients.
STUDY DESIGN, SIZE, DURATION
Retrospective, observational multicenter study of vitrification cycles for FP and of the warming cycles of women who returned to attempt pregnancy from January 2007 to May 2018.
PARTICIPANTS/MATERIALS, SETTING, METHODS
In all, 6362 women (EFP = 5289 patients; 7044 cycles + Onco-FP = 1073 patients; 1172 cycles) had their oocytes vitrified for FP. A logistic regression analysis was performed to examine the impact of indication for FP corrected for age at vitrification. The protocol used for COS was also included as a possible confounder. The main outcome measures were oocyte survival and live birth. A detailed description of the baseline and clinical data is provided, with comparisons between EFP and Onco-FP. The cumulative live birth rate (CLBR) per utilized oocyte according to age at vitrification was analyzed in those patients returning to use their oocytes.
MAIN RESULTS AND ROLE OF CHANCE
Age at vitrification was significantly older in EFP patients (37.2 ± 4.9 vs. 32.3 ± 3.5 year; P < 0.0001). Fewer oocytes were retrieved and vitrified per cycle in EFP (9.6 ± 8.4 vs. 11.4 ± 3.5 and 7.3 ± 11.3 vs. 8.7 ± 2.1, respectively; P < 0.05), but numbers became comparable when analyzed per patient (12.8 ± 7.4 vs. 12.5 ± 3.2 and 9.8 ± 6.4 vs. 9.5 ± 2.6). Storage time was shorter in EFP (2.1 ± 1.6 vs. 4.1 ± 0.9 years; P < 0.0001). In all, 641 (12.1%) EFP and 80 (7.4%) Onco-FP patients returned to attempt pregnancy (P < 0.05). Overall oocyte survival was comparable (83.9% vs. 81.8%; NS), but lower for onco-FP patients among younger (≤35 year) subjects (81.2% vs. 91.4%; P > 0.05). Fewer EFP cycles finished in embryo transfer (50.2% vs. 72.5%) (P < 0.05). The implantation rate was 42.6% and 32.5% in EFP versus Onco-FP (P < 0.05). Ongoing pregnancy (57.7% vs. 35.7%) and live birth rates (68.8% vs. 41.1%) were higher in EFP patients aged ≤35 than the Onco-FP matching age patients (P < 0.05). The reason for FP per se had no effect on oocyte survival (OR = 1.484 95%CI = 0.876-2.252; P = 0.202) or the CLBR (OR = 1.275 95%CI = 0.711-2.284; P = 0.414). Conversely, age (<36 vs. ≥36 y) impacted oocyte survival (adj.OR = 1.922 95%CI = 1.274-2.900; P = 0.025) and the CLBR (adj.OR= 3.106 95%CI = 2.039-4.733; P < 0.0001). The Kaplan-Meier analysis showed a significantly higher cumulative probability of live birth in patients <36 versus >36 in EFP (P < 0.0001), with improved outcomes when more oocytes were available for IVF.
LIMITATIONS, REASONS FOR CAUTION
Statistical power to compare IVF outcomes is limited by the few women who came to use their oocytes in the Onco-FP group. The patients' ages and the COS protocols used were significantly different between the EFP and ONCO-PP groups.
WIDER IMPLICATIONS OF THE FINDINGS
Although the implantation rate was significantly lower in the Onco-FP patients the impact of cancer disease per se was not proven'. EFP patients should be counseled according to their age and number of available oocytes.
STUDY FUNDING/COMPETING INTEREST(S)
No external funding was used for this study. The authors have no conflicts of interest.
TRIAL REGISTRATION NUMBER
N/A.
Iridium oxide based electrodes are among the most promising candidates for electrocatalyzing the oxygen evolution reaction, making it imperative to understand their chemical/electronic structure. ...However, the complexity of iridium oxide's electronic structure makes it particularly difficult to experimentally determine the chemical state of the active surface species. To achieve an accurate understanding of the electronic structure of iridium oxide surfaces, we have combined synchrotron-based X-ray photoemission and absorption spectroscopies with ab initio calculations. Our investigation reveals a pre-edge feature in the O K-edge of highly catalytically active X-ray amorphous iridium oxides that we have identified as O 2p hole states forming in conjunction with Ir(III). These electronic defects in the near-surface region of the anionic and cationic framework are likely critical for the enhanced activity of amorphous iridium oxides relative to their crystalline counterparts.
Water splitting performed in acidic media relies on the exceptional performance of iridium-based materials to catalyze the oxygen evolution reaction (OER). In the present work, we use
X-ray ...photoemission and absorption spectroscopy to resolve the long-standing debate about surface species present in iridium-based catalysts during the OER. We find that the surface of an initially metallic iridium model electrode converts into a mixed-valent, conductive iridium oxide matrix during the OER, which contains O
and electrophilic O
species. We observe a positive correlation between the O
concentration and the evolved oxygen, suggesting that these electrophilic oxygen sites may be involved in catalyzing the OER. We can understand this observation by analogy with photosystem II; their electrophilicity renders the O
species active in O-O bond formation,
the likely potential- and rate-determining step of the OER. The ability of amorphous iridium oxyhydroxides to easily host such reactive, electrophilic species can explain their superior performance when compared to plain iridium metal or crystalline rutile-type IrO
.
Electronic metal–support interactions (EMSI) describe the electron flow between metal sites and a metal oxide support. It is generally used to follow the mechanism of redox reactions. In this study ...of CuO‐CeO2 redox, an additional flow of electrons from metallic Cu to surface carbon species is observed via a combination of operando X‐ray absorption spectroscopy, synchrotron X‐ray powder diffraction, near ambient pressure near edge X‐ray absorption fine structure spectroscopy, and diffuse reflectance infrared Fourier transform spectroscopy. An electronic metal–support–carbon interaction (EMSCI) is proposed to explain the reaction pathway of CO oxidation. The EMSCI provides a complete picture of the mass and electron flow, which will help predict and improve the catalytic performance in the selective activation of CO2, carbonate, or carbonyl species in C1 chemistry.
During the oxidation of CO over the surface of a CuO‐CeO2 catalyst, electrons are simultaneously transferred from Cu0 to lattice Ce4+ and surface carbon species deposited from CO. These “electronic metal–support–carbon interactions” (EMSCI) are thought to play an important role in the reactions involving the support and surface carbon species in C1 chemistry.
•There is a knowledge gap on how pedestrians will interact with automated vehicles.•55 individuals participated in a 360° video-based virtual reality experiment.•A mixed-model binomial logistic ...regression was applied on the data for analysis.•No difference in crossing intentions was found between vehicles’ types.•However, participants with higher trust in automation had higher crossing intentions.
Partially and fully automated vehicles (AVs) are being developed and tested in different countries. These vehicles are being designed to reduce and ultimately eliminate the role of human drivers in the future. However, other road users, such as pedestrians and cyclists will still be present and would need to interact with these automated vehicles. Therefore, external communication interfaces could be added to the vehicle to communicate with pedestrians and other non-automated road users. The first aim of this study is to investigate how the physical appearance of the AV and a mounted external human-machine interface (eHMI) affect pedestrians’ crossing intention. The second aim is to assess the perceived realism of Virtual reality based on 360° videos for pedestrian crossing behavior for research purposes. The speed, time gap, and an eHMIs were included in the study as independent factors. Fifty-five individuals participated in our experiment. Their crossing intentions were recorded, as well as their trust in automation and perceived behavioral control. A mixed binomial logistic regression model was applied on the data for analysis. The results show that the presence of a zebra crossing and larger gap size between the pedestrian and the vehicle increase the pedestrian’s intention to cross. In contrast to our expectations, participants intended to cross less often when the speed of the vehicle was lower. Despite that the vehicle type affected the perceived risk of the participants, no significant difference was found in crossing intention. Participants who recognized the vehicle as an AV had, overall, lower intentions to cross. A strong positive relationship was found between crossing intentions and perceived behavioral control. A difference in trust was found between participants who recognized the vehicle as automated, but this did not lead to a difference in crossing intentions. We assessed the research methodology using the presence questionnaire, the simulation sickness survey, and by comparing the results with previous literature. The method scored highly on the presence questionnaire and only 2 out of 55 participants stopped prematurely. Thus, the research methodology is useful for crossing behavior experiments.
STUDY QUESTION
Can we use morphokinetic markers to select the embryos most likely to implant and are the results likely to be consistent across different clinics?
SUMMARY ANSWER
Yes, morphokinetic ...markers can be used to select the embryos most likely to implant and the results were similar in different IVF clinics that share methods and organization to some extent.
WHAT IS KNOWN ALREADY
With the introduction of time-lapse technology several authors have proposed the use of kinetic markers to improve embryo selection. The majority of these markers can be detected as early as Day 2 of development. Morphology remains the gold standard but kinetic markers have been proven as excellent tools to complement our decisions. Nevertheless, the majority of time-lapse studies are based on small data sets deriving from one single clinic.
STUDY DESIGN, SIZE, DURATION
Retrospective multicentric study of 1664 cycles of which 799 were used to develop an algorithm (Phase 1 of the study) and 865 to test its predictive power (Phase 2 of the study).
PARTICIPANTS/MATERIALS, SETTING, METHODS
University-affiliated infertility centres patients undergoing first or second ICSI cycle using their own or donated oocytes. Embryo development was analysed with a time-lapse imaging system. Variables studied included the timing to two cells (t2), three cells (t3), four cells (t4) and five cells (t5) as well as the length of the second cell cycle (cc2 = t3 − t2) and the synchrony in the division from two to four cells (s2 = t4 − t3). Implantation (IR) and clinical pregnancy (CPR) rates were also analysed.
MAIN RESULTS AND THE ROLE OF CHANCE
During Phase 1 of the study we identified three variables most closely related to implantation: t3 (34–40 h), followed by cc2 (9–12 h) and t5 (45–55 h). Based on these results we elaborated an algorithm that classified embryos from A to D according to implantation potential. During Phase 2 of the study the algorithm was validated in a different group of patients that included 865 cycles and 1620 embryos transferred. In this phase of the study, embryos were categorized based on the algorithm and significant differences in IR were observed between the different categories (‘A’ 32%, ‘B’ 28%, ‘C’ 26%, ‘D’ 20% and ‘E’ 17%, P < 0.001). In addition we identified three quality criteria: direct cleavage from one to three cells, uneven blastomere size in second cell cycle and multinucleation in third cell cycle.
LIMITATIONS, REASONS FOR CAUTION
The retrospective nature of the study limits its potential value, although the use of one database to generate the algorithm (embryos from this database were not selected by any morphokinetic criteria) and one database to validate it reinforces our conclusions.
WIDER IMPLICATIONS OF THE FINDINGS
The elaboration of an algorithm based on a larger database derived from different (albeit related) clinics raises the possibility that such algorithms could be applied in different clinical settings.
STUDY FUNDING/COMPETING INTEREST(S)
No specific funding was obtained for this study; it was solely funded by IVI. None of the authors have any economic affiliation with Unisense Fertilitech A/S but IVI is a minor shareholder in Unisense Fertilitech A/S.
TRIAL REGISTRATION NUMBER
Not applicable.
In this work, a structural analysis of Ge layers deposited by molecular beam epitaxy (MBE) on Ag(1 1 1) surfaces with and without an AlN buffer layer have been investigated by x-ray Absorption ...Spectroscopy (XAS) at the Ge-K edge. For the Ge layers deposited on h-AlN buffer layer on Ag(1 1 1) an interatomic Ge-Ge distance Å is found, typical of 2-Dimensional Ge layers and in agreement with the theoretical predictions for free standing low-buckled Germanene presented in literature. First principles calculations, performed in the density functional theory (DFT) framework, supported the experimental RHEED and XAS findings, providing evidence for the epitaxial 2-D Ge layer formation on h-AlN/Ag(1 1 1) template.
Tremendous effort has been devoted towards elucidating the fundamental reasons for the higher activity of hydrated amorphous Ir
oxyhydroxides (IrO
) in the oxygen evolution reaction (OER) in ...comparison with their crystalline counterpart, rutile-type IrO
, by focusing on the metal oxidation state. Here we demonstrate that, through an analogy to photosystem II, the nature of this reactive species is not solely a property of the metal but is intimately tied to the electronic structure of oxygen. We use a combination of synchrotron-based X-ray photoemission and absorption spectroscopies,
calculations, and microcalorimetry to show that holes in the O 2p states in amorphous IrO
give rise to a weakly bound oxygen that is extremely susceptible to nucleophilic attack, reacting stoichiometrically with CO already at room temperature. As such, we expect this species to play the critical role of the electrophilic oxygen involved in O-O bond formation in the electrocatalytic OER on IrO
. We propose that the dynamic nature of the Ir framework in amorphous IrO
imparts the flexibility in Ir oxidation state required for the formation of this active electrophilic oxygen.
Electrochemically grown cobalt on graphene exhibits exceptional performance as a catalyst for the oxygen evolution reaction (OER) and provides the possibility of controlling the morphology and the ...chemical properties during deposition. However, the detailed atomic structure of this hybrid material is not well understood. To elucidate the Co/graphene electronic structure, we have developed a flow cell closed by a graphene membrane that provides electronic and chemical information on the active surfaces under atmospheric pressure and in the presence of liquids by means of X‐ray photoelectron spectroscopy (XPS). We found that cobalt is anchored on graphene via carbonyl‐like species, namely Co(CO)x, promoting the reduction of Co3+ to Co2+, which is believed to be the active site of the catalyst.
The electronic structure of cobalt on graphene was investigated with a new flow cell that provides electronic and chemical information on the active surfaces by means of X‐ray photoelectron spectroscopy. It is shown that cobalt is anchored on graphene via carbonyl‐like species, promoting the reduction of Co3+ to Co2+, which is believed to be the active site of the catalyst.
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