Abstract
Study question
Can the use of a microfluidic sperm selection device without centrifugation simplify the procedure without affecting fertilization rates and embryonic development after ICSI?
...Summary answer
The microfluidic device can be used to select sperm in a simple procedure without reducing the fertilization or embryo development rate.
What is known already
In human ART, it is essential to process the semen and adjust the sperm sample according to the intended purpose, rather than using raw semen. Current sperm preparation methods at most IVF clinics include the density gradient centrifugation method, which utilizes the difference in density between the maturation stages of sperm, followed by washing using centrifugation. However, these methods require a lot of steps and the procedure is complicated. Recently, several non-centrifugal sperm processing devices have become available. One of them is a simple sperm conditioning method using a microfluidic device.
Study design, size, duration
This was a prospective study using sibling oocytes including 20 ART patients treated with 24 cycles and where there were 320 zygotes after ICSI. The duration of the study was 8 months (May 2020 to December 2020).
Participants/materials, setting, methods
For sperm preparation without centrifugation, a microfluidic device “ZyMōtⓇ Multi 850μL” was used. According to the labelled use, 850μL of semen was required with “ZyMōtⓇ” device (ZyMōt group), and the rest of the semen was processed according to routine laboratory procedure by monolayer density gradient centrifugation and washing by centrifugation (DGC group). Oocytes from the same patient were randomly divided into 2 batches and ICSI was performed using sperm treated with each method.
Main results and the role of chance
The 2PN formation rate in the ZyMōt group was 84.5% (142/168), which was not significantly different from 82.9% (126/152) in the DGC group. There was also no significant difference in 1PN formation rate (3.0% vs. 3.3%), multi PN formation rate (3.6% vs. 3.3%) and the non-fertilization rate (8.3% vs. 10.5%). The good quality embryo rate at Day 3 was 25.0% (31/124) in the ZyMōt group and 24.5% (27/110) in the DGC group, with no significant difference. The Day 5 blastocyst rate was 37.9% (47/124) in the ZyMōt group and 36.7% (40/109) in the DGC group, and the cumulative blastocyst rates by Day 7 were 54.0% (67/124) and 57.8% (63/109), respectively, with no significant difference.
Limitations, reasons for caution
This study was limited to samples with a motile sperm concentration of more over 1.0 × 106 in raw semen.
Wider implications of the findings
These results demonstrated that sperm processing using the microfluidic device without centrifugation does not affect the fertilization or blastocyst development rate after ICSI and that the sperm processing procedure can be simplified by using this device.
Trial registration number
not applicable
Abstract Study question Do differences in the morphological characteristics of embryos or the dynamics of the developmental process affect the results of niPGT analysis? Summary answer Embryos with ...blastomeres that were excluded at compaction showed reduced accuracy of niPGT analysis, but other measured morphological characteristics had no impact. What is known already The PGT-A test, is invasive and requires training to be competent at the technique, aswell as the need for specialized equipment and consumables. In recent years, non-invasive PGT-A (niPGT-A), which analyzes Cell-Free DNA released from cultured embryos, has been attracting attention. Regarding the analysis accuracy of niPGT-A, there are reports that it is equivalent to or even superior to conventional PGT-A. However, at present, it is not clear how methodological differences or embryo dynamics impact results. Study design, size, duration From August 2021 to February 2022, 284 pronuclear-stage frozen embryos (with consent for research use), were thawed and cultured. They were individually cultured for at least 40 hours after Day 4. For the 150 embryos that reached the blastocyst stage, culture medium and the blastocysts were collected and subjected to chromosome aneuploidy analysis by NGS. For the 138 blastocyst with a result, the concordance rate was calculated with that obtained from the culture medium samples. Participants/materials, setting, methods The embryos were individually cultured in a single step medium using a 10 μl droplet from Day 4. The entire culture period was recorded in a time-lapse incubator. The concordance rate for all chromosomes between culture medium sample and the blastocyst was compared to recorded embryo dynamics, e.g. presence or absence of cumulus cell attachment, sperm attachment, fragmentation, blastomeres that excluded at compaction, shrinkage, and hatching. Chi-square test was used to compare the concordance rates. Main results and the role of chance The overall concordance rate for all chromosomes between the culture medium and the blastocysts samples was 46.4%(64/138). In the blastocysts where there were cumulus cells attached or not it was 43.6% (17/39) vs 47.5% (47/99) respectively, cases where there was still a sperm attached or not it was 53.1% (17/32) vs 44.3% (47/106) resepctively and in blastocysts where there had been fragmentation or no fragmenattion it was 46.9%(38/81) vs 45.6％(26/57) respectively. In cases where shrinkage of the blastocyst had been observed vs no shrinkage the respective concordance rates were 44.9% (48/107) vs 51.6% (16/31), whilst in cases where the blastocyst had hatched or not it was 40.6% (13/32) vs 48.1% (51/106) respectively.For the blastocysts where the blastomeres had been excluded at compaction or not it was 35.6％(31/87) vs 64.7% (33/51) respectively.Significant differences were only identified in cases with blastomere exclusion or no exclusion at compaction (P < 0.01). Limitations, reasons for caution In this study, the culture was continued to day 6 regardless of morphology of the embryo on day 5, which differs from the usual clinical culture process. Wider implications of the findings These results are useful in that they may aid in recognising which morphological features of embryos may impact the results obtained from niPGT and hence its reliability for clinical application. The blastomeres that excluded at compaction are clearly important for improving the accuracy of the niPGT analysis in the future. Trial registration number None
Abstract Study question Is niPGT on culture medium exposed for 24 hours to vitrified-thawed blastocysts useful? Summary answer niPGT using a culture medium from vitrified blastocysts cultured for ...24hours after thawing showed a high concordance rate with the PGTa results. What is known already Conventional PGTa, which is widely practiced around the world, requires specialized techniques and involves embryonic trophectoderm (TE) biopsy. Recently, niPGT using cell free DNA released from embryos into culture medium has been reported as an alternative to conventional PGT, and has been found to correlate well with TE-biopsy analysis results (Carmen. Rubio, 2020). Although there have been numerous reports of niPGT accuracy based on the timing of culture medium collection, there have been few comparisons of its accuracy based on different time points of medium collection from the same embryo. Study design, size, duration From March to April 2023, 128 vitrified pronuclear stage embryos from 33 patients with consent for research use, were thawed and cultured, and from Day 4, they were individually cultured for over 40 hours. 60 embryos that reached blastocyst by Day 6 were vitrified, and the spent culture medium (SCM1) was collected. The vitrified blastocysts were later thawed and cultured individually for 24 hours, and then the embryos and spent culture medium (SCM2) were collected. Participants/materials, setting, methods Embryos were cultured in a 30 μl droplet until Day 4 and a 10 μl droplet for individual culture. Culture medium was collected and embryos were subjected to chromosomal analysis by NGS. We compared the results of niPGT taken from the same embryos on days 4- 6 (SCM1) and after thawing of vitrified blastocysts (SCM2), with PGTa analysis of the embryos. Main results and the role of chance Among all media samples analyzed, results were obtained for 80.0% (48/60) SCM1 and 96.7% (58/60) SCM2 samples. The ploidy concordance rate was 81.3% (39/48) for SCM1 and 98.3% (57/58) for SCM2. The overall concordance rate, defined as the combined rate of the total concordance for all chromosomes and the partial concordance for some chromosomes was 72.9% (35/48) for SCM1 and 94.8% (55/58) for SCM2 respectively. Significant differences were identified in the informative sample rate, the ploidy concordance rate, and the overall concordance rate(p < 0.05) between SCM1 and SCM2. Fisher’s exact test was used for statistical analysis. Limitations, reasons for caution In this study, embryo culture was continued to day 6, regardless of morphology of the embryo at day 5, which differs from the usual clinical culture process. Additionally, the timing of sample collection differed between the day 4-6 culture medium sample and that for a blastocyst. Wider implications of the findings The results demonstrated that accuracy of ploidy status was higher in the SCM2 compared to the SCM1 sample, suggesting that analysis of thawed vitrified blastocyst medium maybe a more precise predictor and therefore a non-invasive alternative to conventional PGTa. Trial registration number not applicable
Abstract Study question Is there a difference in performance between artificial intelligence(AI) algorithms that predict the likelihood of pregnancy from a single blastocyst image compared to ...time-lapse videos? Summary answer The performance of AI to predict pregnancy from a single blastocyst image was similar to the performance of an AI using time-lapse video. What is known already Vitrolife’s “iDAScore (iDA)” and Presagen’s Life Whisperer Viability (LW) are AI systems trained on videos (iDA) or images (LW) of blastocysts, with corresponding pregnancy outcomes (fetal heartbeat). iDA requires a dedicated time-lapse incubator and uses multiple images to predict pregnancy. LW requires only one image taken with a camera that meets image quality requirements. However, as tools for selecting viable embryos for transfer, these methods adopt different approaches: iDA relying on multiple morphokinetic timepoints to achieve prediction based on past embryo development, and LW relying on predictive analytics from morphological assessment at the decision point prior to transfer. Study design, size, duration 359 embryos cultured in EmbryoScope +/8 that reached blastocyst stage (Gardner classification ≥1) on Day 5 were utilised for first single vitrified blastocyst transfer (between 2018-2021). Pregnancy prediction was scored from EmbryoScope’s embryo images using iDA and LW, and a dataset was created with fetal heartbeat as the outcome. Participants/materials, setting, methods iDA data was classified into quartiles (Low, Medium, High, Very High) and LW into the manufacturers’ recommended four categories (Low, Medium, High, Very High). The trend of pregnancy outcome and respective scores were evaluated using a trend test (Cochran-Armitage test). Additionally, the Quadratic Weighted Kappa coefficient was used to evaluate the concordance of the categories. The Area Under the Roc Curve (AUC) for each prediction accuracy was also determined and compared using Delong’s test. Main results and the role of chance A trend of increasing pregnancy rate was observed for both methods as the score category increased (iDA: Low 35.2%, Medium 46.9%, High 52.1%, Very High 65.4%; LW: Low 36.0%, Medium 46.3%, High 60.5%, Very High 63.4%). The respective AUCs were iDA: 0.635 LW: 0.627, (not significantly different; P = 0.732). The Quadratic Weighted Kappa coefficient was 0.622, indicating that the categories of evaluation were consistent. Limitations, reasons for caution This is a retrospective study performed in a single clinic. In addition, the study was limited to transfer cycles of embryos where blastocyst formation was reached on day 5 of culture. Wider implications of the findings These results indicate that an AI that predicts pregnancy from a single blastocyst image can perform equally well compared to AI that predicts pregnancy from time-lapse videos. This suggests that tracking of morphokinetic timepoints during embryo development may be less important than end-point morphology for predicting pregnancy at blastocyst stage. Trial registration number not applicable
Photobiological hydrogen production Asada, Yasuo; Miyake, Jun
Journal of Bioscience and Bioengineering,
1999, Volume:
88, Issue:
1
Book Review, Journal Article
Peer reviewed
The principles and recent progress in the research and development of photobiological hydrogen production are reviewed. Cyanobacteria produce hydrogen gas using nitrogenase and/or hydrogenase. ...Hydrogen production mediated by native hydrogenases in cyanobacteria occurs under in the dark under anaerobic conditions by degradation of intracellular glycogen.
In vitro and
in vivo coupling of the cyanobacterial photosynthetic system with a clostridial hydrogenase via cyanobacterial ferredoxin was demonstrated in the presence of light. Genetic transformation of
Synechococcus PCC7942 with the hydrogenase gene from
Clostridium pasteurianum was successful; the active enzyme was expressed in PCC7942. The strong hydrogen producers among photosynthetic bacteria were isolated and characterized. Coculture of
Rhodobacter and
Clostriudium was applied for hydrogen production from glucose. A mutant strain of
Rhodobacter sphaeroides RV whose light-harvesting proteins were altered was obtained by UV irradiation. Hydrogen productivity by the mutant was improved when irradiated with monochromatic light of some wavelengths. The development of photobioreactors for hydrogen production is also reviewed.
Full text
Available for:
IJS, IMTLJ, KILJ, KISLJ, NUK, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The charge-conjugation and parity-reversal (CP) symmetry of fundamental particles is a symmetry between matter and antimatter. Violation of this CP symmetry was first observed in 1964
, and CP ...violation in the weak interactions of quarks was soon established
. Sakharov proposed
that CP violation is necessary to explain the observed imbalance of matter and antimatter abundance in the Universe. However, CP violation in quarks is too small to support this explanation. So far, CP violation has not been observed in non-quark elementary particle systems. It has been shown that CP violation in leptons could generate the matter-antimatter disparity through a process called leptogenesis
. Leptonic mixing, which appears in the standard model's charged current interactions
, provides a potential source of CP violation through a complex phase δ
, which is required by some theoretical models of leptogenesis
. This CP violation can be measured in muon neutrino to electron neutrino oscillations and the corresponding antineutrino oscillations, which are experimentally accessible using accelerator-produced beams as established by the Tokai-to-Kamioka (T2K) and NOvA experiments
. Until now, the value of δ
has not been substantially constrained by neutrino oscillation experiments. Here we report a measurement using long-baseline neutrino and antineutrino oscillations observed by the T2K experiment that shows a large increase in the neutrino oscillation probability, excluding values of δ
that result in a large increase in the observed antineutrino oscillation probability at three standard deviations (3σ). The 3σ confidence interval for δ
, which is cyclic and repeats every 2π, is -3.41, -0.03 for the so-called normal mass ordering and -2.54, -0.32 for the inverted mass ordering. Our results indicate CP violation in leptons and our method enables sensitive searches for matter-antimatter asymmetry in neutrino oscillations using accelerator-produced neutrino beams. Future measurements with larger datasets will test whether leptonic CP violation is larger than the CP violation in quarks.
Full text
Available for:
FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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