Science.gov

Sample records for single blastocyst transfer

  1. Association between blastocyst morphology and outcome of single-blastocyst transfer.

    PubMed

    Van den Abbeel, Etienne; Balaban, Basak; Ziebe, Søren; Lundin, Kersti; Cuesta, Maria José Gómez; Klein, Bjarke Mirner; Helmgaard, Lisbeth; Arce, Joan-Carles

    2013-10-01

    The aim of this study was to assess the ability of three individual blastocyst morphology parameters - expansion and hatching (EH) stage, inner cell mass (ICM) grade and trophectoderm grade - to predict outcome of a cycle with single-blastocyst transfer. The study was a secondary analysis of data prospectively collected in a large multicentre trial. A total of 618 intracytoplasmic sperm injection patients undergoing ovarian stimulation in a gonadotrophin-releasing hormone antagonist cycle with compulsory single-blastocyst transfer on day 5 were included. In the simple logistic regression analysis, all three blastocyst morphology parameters were statistically significantly (P<0.005 for each) associated with positive human chorionic gonadotrophin, clinical and ongoing pregnancy rates and live birth rates, while only the ICM grade was significantly (P=0.033) associated with early pregnancy loss rate. Blastocyst EH stage was the only significant predictor of live birth (P=0.002) in the multiple logistic regression. In conclusion, although all three blastocyst morphology parameters were related to treatment outcome of fresh single-blastocyst cycles, selection of high-quality blastocysts for transfer should consider first the EH stage. Transfer of a blastocyst with ICM grade A may reduce the risk of early pregnancy loss. Choosing the embryo(s) with the best implantation potential is essential for securing each couple the highest chance of achieving pregnancy after assisted reproduction. The selection of embryo(s) for transfer at the blastocyst stage is based on morphology parameters of expansion and hatching stage, inner cell mass grade and trophectoderm grade. The aim of this study was to assess the relative impact of each parameter in predicting the probability of a successful outcome. The study was a secondary analysis of data prospectively collected in a large multicentre trial. A total of 618 patients who underwent single-blastocyst transfer on day 5 were included

  2. Elective single blastocyst transfer in women older than 35.

    PubMed

    Davis, Lynn B; Lathi, Ruth B; Westphal, Lynn M; Milki, Amin A

    2008-01-01

    A retrospective review of all patients older than 35 who underwent elective single blastocyst transfer was performed. Twenty-three of the 45 patients (51.1%) have an ongoing pregnancy or liveborn delivery, with a mean age of 37.3 years, demonstrating a clear role for elective single transfer in this relatively older IVF population.

  3. Comparable clinical outcomes and live births after single vitrified-warmed and fresh blastocyst transfer.

    PubMed

    Feng, Guixue; Zhang, Bo; Zhou, Hong; Shu, Jinhui; Gan, Xianyou; Wu, Fangrong; Deng, Xihe

    2012-11-01

    Selective single-blastocyst transfer (SBT) in fresh cycles has been effective in reducing multiple pregnancies. However, we do not know whether this successful strategy of fresh transfer cycles is suitable for cryopreserved cycles. The present study was undertaken to evaluate the feasibility and value of SBT in vitrified-warmed cycles. Clinical pregnancy rate (CPR) was similar with vitrified and fresh SBT (46.61% versus 52.15% respectively). Of the pregnant patients, monozygotic twin, miscarriage and ectopic pregnancy rates were similar with vitrified and fresh SBT. For the newborns, no significant difference was observed in live birth, low birthweight, premature delivery and birth defects rates between vitrified and fresh SBT. With respect to the quality of transferred blastocysts (from BB to AA), a similar CPR and miscarriage rate was obtained for both vitrified and fresh SBT when a similar blastocyst cohort graded ≥ 3BB was transferred. The data show that vitrified SBT is an effective means of reducing multiple pregnancy and that comparable clinical outcomes and live births are achieved if single blastocysts graded ≥ 3BB are transferred for both vitrified and fresh SBT. These data should encourage clinics to evaluate their embryo transfer policy and adopt vitrified SBT as everyday practice. Selective single-blastocyst transfer in fresh cycles has been an effective method to reduce the multiple pregnancies. However, due to a lack of adequate studies, we do not know whether this successful strategy in fresh transfer cycles is suitable in cryopreserved cycles. The present study was undertaken to explore the feasibility and value of single-blastocyst transfer in vitrified-warmed cycles. We found that single-blastocyst transfer in vitrified-warmed cycles is an effective means of reducing multiple pregnancy, and comparable clinical outcomes and live births were achieved if single blastocysts graded ≥ 3BB were transferred for both vitrified-warmed and fresh

  4. Clinical outcomes of single versus double blastocyst transfer in fresh and vitrified-warmed cycles

    PubMed Central

    Eum, Jin Hee; Park, Jae Kyun; Kim, So Young; Paek, Soo Kyung; Seok, Hyun Ha; Chang, Eun Mi; Lee, Woo Sik

    2016-01-01

    Objective Assisted reproductive technology has been associated with an increase in multiple pregnancies. The most effective strategy for reducing multiple pregnancies is single embryo transfer. Beginning in October 2015, the National Supporting Program for Infertility in South Korea has limited the number of embryos that can be transferred per in vitro fertilization (IVF) cycle depending on the patient's age. However, little is known regarding the effect of age and number of transferred embryos on the clinical outcomes of Korean patients. Thus, this study was performed to evaluate the effect of the number of transferred blastocysts on clinical outcomes. Methods This study was carried out in the Fertility Center of CHA Gangnam Medical Center from January 2013 to December 2014. The clinical outcomes of 514 women who underwent the transfer of one or two blastocysts on day 5 after IVF and of 721 women who underwent the transfer of one or two vitrified-warmed blastocysts were analyzed retrospectively. Results For both fresh and vitrified-warmed cycles, the clinical pregnancy rate and live birth or ongoing pregnancy rate were not significantly different between patients who underwent elective single blastocyst transfer (eSBT) and patients who underwent double blastocyst transfer (DBT), regardless of age. However, the multiple pregnancy rate was significantly lower in the eSBT group than in the DBT group. Conclusion The clinical outcomes of eSBT and DBT were equivalent, but eSBT had a lower risk of multiple pregnancy and is, therefore, the best option. PMID:27689039

  5. Clinical outcomes of frozen-thawed single blastocyst transfer in patients requiring whole embryo freezing.

    PubMed

    He, Qiao-hua; Wang, Lu; Liang, Lin-lin; Zhang, He-long; Zhang, Cui-lian; Li, Hang-sheng; Cui, Shi-hong

    2016-01-01

    We compared clinical outcomes amongst frozen-thawed cleavage-stage embryo, double and single blastocyst transfers in patients requiring whole embryo freezing. Data of infertile patients undergoing in-vitro fertilization and embryo transfer (IVF-ET) in our Reproductive Medicine Center from January 2010 to December 2012 were retrospectively analyzed. According to patients' wishes, patients were divided into cleavage-stage embryo transfer groups (group A, n = 456), double blastocyst transfer group (group B, n = 106), and single blastocyst transfer group (group C, n = 402). We found that the number of frozen embryos was significantly less in groups B and C than in group A (all p < 0.05), but the implantation rate was significantly higher in groups B and C as compared to group A (all p < 0.05). The clinical pregnancy rate and pregnancy rate per included cycle were significantly higher in group B than in groups A and C (all p < 0.05). The multiple pregnancy rate was significantly lower in group C than in groups A and B (all p < 0.05). The rate of early abortion was significantly lower in group C as compared to group A (p < 0.05). The data support the view that it may be the best clinical strategy for patients who require whole embryo freezing and have four or more Day 3 embryos available, to incubate Day 3 embryos into blastocysts, which are then vitrified for elective single blastocyst transfer.

  6. Successful pregnancy following single blastocyst transfer in a renal transplant recipient

    PubMed Central

    Muthuvel, V. Arun; Ravindran, Manipriya; Chander, Aravind; Veluswamy, Chandralekha

    2016-01-01

    Numerous spontaneous pregnancies have been reported in renal transplant recipients; however, only a few pregnancies after the use of assisted reproductive techniques. The authors report a case of renal transplant recipient with secondary infertility who delivered a healthy baby without any complications. The report highlights the importance of minimal stimulation protocol during ovarian stimulation, single embryo transfer, and the need for multispecialty care for these patients. To the best of the authors' knowledge, the present report is the first such case from India and also the second in the world to report a blastocyst transfer among renal transplant recipients. PMID:27110079

  7. Age-Related Success with Elective Single versus Double Blastocyst Transfer.

    PubMed

    Friedman, Brooke E; Davis, Lynn B; Lathi, Ruth B; Westphal, Lynn M; Baker, Valerie L; Milki, Amin A

    2011-01-01

    Background. Although the optimal outcome of assisted reproductive technology (ART) is a healthy singleton pregnancy, the rate of twin gestation from ART in women over the age of 35 is persistently high. Methods/Findings. We compared clinical pregnancy rates (PRs), ongoing pregnancy/live birth rates, and multiple gestation rates (MGRs) in 108 women who chose elective single blastocyst transfer (eSBT) to 415 women who chose elective double blastocyst transfer (eDBT) at a hospital-based IVF center. There was no significant difference in PR between eSBT and eDBT (57.4% versus 50.2%, P = 0.47) nor between eSBT and eDBT within each age group: <35, 35-37, 38-40, and >40. The risk of multiple gestations, however, was greatly increased between eSBT and eDBT (1.6 versus 32.4%, P < 0.00005), and this difference did not vary across age groups. Conclusion(s). Women undergoing eDBT are at uniformly high risk of multiple gestation regardless of age. eSBT appears to significantly lower the risk of multiple gestation without compromising PR.

  8. Age-Related Success with Elective Single versus Double Blastocyst Transfer

    PubMed Central

    Friedman, Brooke E.; Davis, Lynn B.; Lathi, Ruth B.; Westphal, Lynn M.; Baker, Valerie L.; Milki, Amin A.

    2011-01-01

    Background. Although the optimal outcome of assisted reproductive technology (ART) is a healthy singleton pregnancy, the rate of twin gestation from ART in women over the age of 35 is persistently high. Methods/Findings. We compared clinical pregnancy rates (PRs), ongoing pregnancy/live birth rates, and multiple gestation rates (MGRs) in 108 women who chose elective single blastocyst transfer (eSBT) to 415 women who chose elective double blastocyst transfer (eDBT) at a hospital-based IVF center. There was no significant difference in PR between eSBT and eDBT (57.4% versus 50.2%, P = 0.47) nor between eSBT and eDBT within each age group: <35, 35–37, 38–40, and >40. The risk of multiple gestations, however, was greatly increased between eSBT and eDBT (1.6 versus 32.4%, P < 0.00005), and this difference did not vary across age groups. Conclusion(s). Women undergoing eDBT are at uniformly high risk of multiple gestation regardless of age. eSBT appears to significantly lower the risk of multiple gestation without compromising PR. PMID:22191047

  9. Women's age and embryo developmental speed accurately predict clinical pregnancy after single vitrified-warmed blastocyst transfer.

    PubMed

    Kato, Keiichi; Ueno, Satoshi; Yabuuchi, Akiko; Uchiyama, Kazuo; Okuno, Takashi; Kobayashi, Tamotsu; Segawa, Tomoya; Teramoto, Shokichi

    2014-10-01

    The aim of this study was to establish a simple, objective blastocyst grading system using women's age and embryo developmental speed to predict clinical pregnancy after single vitrified-warmed blastocyst transfer. A 6-year retrospective cohort study was conducted in a private infertility centre. A total of 7341 single vitrified-armed blastocyst transfer cycles were included, divided into those carried out between 2006 and 2011 (6046 cycles) and 2012 (1295 cycles). Clinical pregnancy rate, ongoing pregnancy rate and delivery rates were stratified by women's age (<35, 35-37, 38-39, 40-41, 42-45 years) and time to blastocyst expansion (<120, 120-129, 130-139, 140-149, >149 h) as embryo developmental speed. In all the age groups, clinical pregnancy rate, ongoing pregnancy rate and delivery rates decreased as the embryo developmental speed decreased (P < 0.0001). A simple five-grade score based on women's age and embryo developmental speed was determined by actual clinical pregnancy rates observed in the 2006-2011 cohort. Subsequently, the novel grading score was validated in the 2012 cohort (1295 cycles), finding an excellent association. In conclusion, we established a novel blastocyst grading system using women's age and embryo developmental speed as objective parameters.

  10. Cytogenetic analysis of the retained products of conception after missed abortion following blastocyst transfer: a retrospective, large-scale, single-centre study.

    PubMed

    Segawa, Tomoya; Kuroda, Tomoko; Kato, Keiichi; Kuroda, Masako; Omi, Kenji; Miyauchi, Osamu; Watanabe, Yoshiaki; Okubo, Tsuyoshi; Osada, Hisao; Teramoto, Shokichi

    2017-02-01

    Cytogenetic analysis of the retained products of conception (POC) is the most effective test for identifying miscarriage causes. However, there has been no large-scale study limited to blastocyst transfer. This study retrospectively reports the findings of 1030 cases in which POC analysis was performed after missed abortion following single blastocyst transfer performed at the Shinbashi Yume Clinic. We identified 19.4% as normal karyotypes and 80.6% as aneuploid. These cases broke down into: 62.3% trisomy; 7.8% double trisomy; 0.5% triple or quadruple trisomy; 1.3% monosomy 21; 3.2% monosomy X; 0.1% 47,XXY; 1.0% polyploidy; 1.0% mixed; 1.1% embryonic mosaicism; and 2.4% structural anomalies. In samples with normal karyotypes, 49.5% were female while 50.5% were male. The occurrence of trisomy and double trisomy were both significantly more frequent in the ≥38 years group than in the ≤37 years group (P < 0.01). Trisomy was significantly more frequently associated with fetal heartbeat (P < 0.01); double trisomy, polyploidy and normal karyotype were significantly more frequent with no fetal heartbeat (P < 0.01). There was no significant difference in the frequency of chromosomal abnormalities between the number of miscarriages or blastocyst quality. Thus, POC cytogenetic testing is highly valuable for ascertaining the cause of miscarriage.

  11. Should we be promoting embryo transfer at blastocyst stage?

    PubMed

    Maheshwari, Abha; Hamilton, Mark; Bhattacharya, Siladitya

    2016-02-01

    Improved laboratory standards and better culture media have made extended culture to blastocyst stage a reality to identify embryos with maximum implantation potential. The strategy of extended culture has become more popular across the world at a time when regulatory bodies have emphasized the need to increase the uptake of elective single embryo transfer, minimize complications associated with multiple births and aim for a healthy singleton live-birth as the preferred outcome in IVF. New data on perinatal outcomes suggest that pregnancies after embryo transfer at blastocyst stage are associated with a higher risk of preterm delivery, large for gestational age babies, monozygotic twins and altered sex ratio compared with those following embryo transfers at cleavage stage. In addition, concerns have been raised of increased congenital anomalies and epigenetic modifications with embryo transfer at blastocyst stage. Twenty-four years on from the first embryo transfer at blastocyst stage, we examine the reasons for extended embryo culture, evaluate the risks and benefits of this strategy and suggest the need to reconsider this policy in the interests of fetal safety.

  12. Outcomes of blastocysts biopsied and vitrified once versus those cryopreserved twice for euploid blastocyst transfer.

    PubMed

    Taylor, Tyl H; Patrick, Jennifer L; Gitlin, Susan A; Michael Wilson, J; Crain, Jack L; Griffin, Darren K

    2014-07-01

    Trophectoderm biopsy with comprehensive chromosome screening (CCS) has been shown to increase implantation and pregnancy rates. Some patients desire CCS on previously cryopreserved blastocysts, resulting in blastocysts that are thawed/warmed, biopsied, vitrified and then warmed again. The effect of two cryopreservation procedures and two thawing/warming procedures on outcomes has not been effectively studied. Cycles were divided into two groups: group 1 patients underwent a cryopreserved embryo transfer with euploid blastocysts that were vitrified and warmed once; group 2 patients had a cryopreserved embryo transfer of a euploid blastocyst that was cryopreserved, thawed/warmed, biopsied, vitrified and warmed. Groups 1 and 2 included 85 and 17 women aged 35.6 ± 3.9 and 35.3 ± 4.9 years, respectively (not significantly different). Blastocyst survival in group 1 (114/116, 98.3%) and survival of second warming in group 2 (21/24, 87.5%) was significantly different (P = 0.0354). There was no difference between biochemical (68.2% and 62.5%) and clinical (61.2% and 56.3%) pregnancy rates, implantation rate (58.4% and 52.4%) and live birth/ongoing pregnancy rate (54.0% and 47.6%) between groups 1 and 2, respectively. Although it is unconventional to thaw/warm, biopsy, revitrify and rewarm blastocysts for cryopreserved embryo transfer, the results indicate that outcomes are not compromised. Trophectoderm biopsy and screening the embryos for chromosomal abnormalities has been reported to increase implantation and pregnancy rates. There is a category of patients requesting chromosomal screening on previously cryopreserved blastocysts. This scenario requires blastocysts to be thawed/warmed, biopsied, cryopreserved, and thawed/warmed again. The effect of double cryopreservation procedures and double thawing/warming procedures on pregnancy is unknown. Patients were divided into two groups, group 1 underwent a cryopreserved embryo transfer with a chromosomally normal blastocyst

  13. Comparison of clinical outcomes following vitrified warmed day 5/6 blastocyst transfers using solid surface methodology with fresh blastocyst transfers

    PubMed Central

    Muthukumar, K; Kamath, Mohan S; Mangalaraj, Ann M; Aleyamma, TK; Chandy, Achamma; George, Korula

    2013-01-01

    OBJECTIVES: The literature regarding clinical outcomes following day 5/6 vitrified warmed blastocysts transfer has been conflicting. We decided to evaluate and compare the clinical outcomes following vitrified warmed day 5/6 blastocyst transfer using a solid surface vitrification protocol with fresh blastocyst transfers. SETTINGS: University teaching hospital. STUDY DESIGN: A total of 249 women were retrospectively analyzed: 146 fresh day 5 blastocyst (group 1), 57 day 5 vitrified warmed blastocyst (group 2), and 46 vitrified warmed day 6 blastocyst (group 3) transfer cycles. Vitrification was done using solid surface methodology (non immersion protocol). The main outcomes were implantation rates, clinical pregnancy, and live birth rate per embryo transfer. RESULTS: The baseline clinical characteristics were similar among all three groups. The implantation and clinical pregnancy rates following vitrified warmed day 6 blastocyst transfers (20.9% and 32.6%) were significantly lower as compared to day 5 fresh and vitrified warmed day 5 blastocyst transfers (40.3% and 56.1%, 36.3%, and 52.6%). However, there was no significant difference in the live birth rates across the three groups (group 1: 37.6%, group 2: 40.3%, and group 3: 28.2%). CONCLUSION: No statistically significant difference was observed in live birth rates between fresh day 5 blastocyst transfers and vitrified warmed day 5/6 blastocyst transfers. Vitrification of blastocysts using solid surface methodology is an efficient method of cryopreservation. PMID:23869154

  14. Successful frozen blastocyst transfers after failed fresh transfers in assisted reproductive technologies patients with hydrosalpinx.

    PubMed

    Sueldo, Carolina M; Milki, Amin A; Lathi, Ruth B

    2012-03-01

    Untreated hydrosalpinx is known to decrease in vitro fertilization success. We report on 4 patients with hydrosalpinx for whom fresh transfers of 11 good quality embryos did not produce a pregnancy; however, frozen blastocyst transfers in natural cycles resulted in several successful pregnancies, with an implantation rate of 60% (9/15 blastocysts implanted).

  15. Perinatal Risks Associated with Early Vanishing Twin Syndrome following Transfer of Cleavage- or Blastocyst-Stage Embryos

    PubMed Central

    Pryor, Katherine P.; Petrini, Allison C.; Lekovich, Jovana P.; Stahl, Jaclyn; Elias, Rony T.; Spandorfer, Steven D.

    2016-01-01

    Objective. To investigate whether the perinatal risks associated with early vanishing twin (VT) syndrome differ between cleavage- or blastocyst-stage embryo transfers (ET) in fresh in vitro fertilization (IVF) cycles. Methods. Retrospective, single-center, cohort study of IVF cycles with fresh cleavage- or blastocyst-stage ETs resulting in a live singleton birth. The incidence of preterm birth (PTB), low birth weight (LBW), and very low birth weight (VLBW) was compared between cleavage- and blastocyst-stage ET cycles complicated by early VT. Results. 7241 patients had live singleton births. Early VT was observed in 709/6134 (11.6%) and 70/1107 (6.32%) patients undergoing cleavage-stage and blastocyst-stage ETs, respectively. Patients in the blastocyst-stage group were younger compared to the cleavage-stage group. The cleavage-stage group had a similar birth weight compared to the blastocyst-stage group. There was no difference in the incidence of PTB (9.87% versus 8.57%), LBW (11.1% versus 11.4%), or VLBW (1.13 versus 1.43%) when comparing the cleavage-stage early VT and blastocyst-stage early VT groups, even after adjustment with logistic regression. Conclusions. Our study highlights that the adverse perinatal risks of PTB, LBW, and VLBW associated with early VT syndrome are similar in patients undergoing cleavage-stage or blastocyst-stage ETs during fresh IVF cycles. PMID:28101380

  16. Simultaneous gene quantitation of multiple genes in individual bovine nuclear transfer blastocysts.

    PubMed

    Smith, Craig; Berg, Debbie; Beaumont, Sue; Standley, Neil T; Wells, David N; Pfeffer, Peter L

    2007-01-01

    During somatic cell nuclear transfer (NT), the transcriptional status of the donor cell has to be reprogrammed to reflect that of an embryo. We analysed the accuracy of this process by comparing transcript levels of four developmentally important genes (Oct4, Otx2, Ifitm3, GATA6), a gene involved in epigenetic regulation (Dnmt3a) and three housekeeping genes (beta-actin, beta-tubulin and GAPDH) in 21 NT blastocysts with that in genetically half-identical in vitro produced (IVP, n=19) and in vivo (n=15) bovine embryos. We have optimised an RNA-isolation and SYBR-green-based real-time RT-PCR procedure allowing the reproducible absolute quantification of multiple genes from a single blastocyst. Our data indicated that transcript levels did not differ significantly between stage and grade-matched zona-free NT and IVP embryos except for Ifitm3/Fragilis, which was expressed at twofold higher levels in NT blastocysts. Ifitm3 expression is confined to the inner cell mass at day 7 blastocysts and to the epiblast in day 14 embryos. No ectopic expression in the trophectoderm was seen in NT embryos. Gene expression in NT and IVP embryos increased between two- and threefold for all eight genes from early to late blastocyst stages. This increase exceeded the increase in cell number over this time period indicating an increase in transcript number per cell. Embryo quality (morphological grading) was correlated to cell number for NT and IVP embryos with grade 3 blastocysts containing 30% fewer cells. However, only NT embryos displayed a significant reduction in gene expression (50%) with loss of quality. Variability in gene expression levels was not significantly different in NT, IVP or in vivo embryos but differed among genes, suggesting that the stringency of regulation is intrinsic to a gene and not affected by culture or nuclear transfer. Oct4 levels exhibited the lowest variability. Analysing the total variability of all eight genes for individual embryos revealed that in

  17. Fresh transfer outcome predicts the success of a subsequent frozen transfer utilizing blastocysts of the same cohort.

    PubMed

    Doherty, L F; Martin, J R; Kayisli, U; Sakkas, D; Patrizio, P

    2014-02-01

    The objective of this retrospective analysis was to assess whether the outcomes of fresh blastocyst transfer cycles are predictive of the chances for pregnancy and live birth in subsequent frozen blastocyst transfer cycles using sibling embryos from the same retrieval. Clinical pregnancy rate (CPR) and live birth rate (LBR) per fresh and frozen blastocyst transfer were assessed. All subgroups had similar patient and cycle characteristics. Overall, CPR and LBR in fresh cycles were 44% and 29%, and in frozen were 34% and 30%, respectively. However, the CPR and LBR in frozen cycles were significantly higher in patients who were not pregnant with their fresh cycles (CPR 43% versus 22%, P=0.01; and LBR 36% versus 17%, P=0.03, respectively). When fresh cycles are unsuccessful, the remaining frozen blastocysts of the same cohort have the same chance of success in producing a clinical pregnancy as the fresh cycle (43% versus 44%). Frozen cycles following successful fresh cycles have significantly lower CPR and LBR. These data reinforce the concept that only a few embryos per cohort are competent for a live birth. During IVF cycles, many patients are fortunate enough to have excess high-quality embryos remaining after their embryo transfer. These embryos can be frozen, or cryopreserved, for later transfer. The transfer of cryopreserved embryos increases the cumulative success rates after a single IVF stimulation. Many studies have examined success rates such as clinical pregnancy rate and live birth rate in frozen embryo transfer cycles. While these frozen embryo transfer cycles have excellent success rates, they are significantly lower than success rates in cycles where a "fresh", non-frozen, embryo is transferred. Few studies have carefully examined the impact of the result of the fresh embryo transfer (whether the patient became pregnant or not) on subsequent frozen embryo transfer success. Here we show that women who are not pregnant after a fresh embryo transfer have

  18. Live birth from previously vitrified oocytes, after trophectoderm biopsy, revitrification, and transfer of a euploid blastocyst.

    PubMed

    Grifo, Jamie A; Hodes-Wertz, Brooke; Lee, Hsiao Ling; Ampeloquio, Esmeralda; Clarke-Williams, Melicia; Adler, Alexis; Munné, Santiago; Berkeley, Alan S

    2013-09-10

    Our objective is to describe a successful live birth from oocyte vitrification followed by thaw, fertilization, blastocyst culture, trophectoderm biopsy, vitrification, and subsequent thaw. Fifteen mature oocytes were frozen from a patient with uterine factor infertility. Thirteen oocytes survived the thaw, and five underwent trophectoderm biopsy and were refrozen. Three euploid embryos were obtained. A single euploid embryo was transferred in the second thaw cycle to a known recipient leading to the delivery of a normal male infant. This case report is proof of the concept that preimplantation screening and diagnosis is an option for fertility preservation patients.

  19. [Heterotopic pregnancy with intrauterine dizygotic twins following embryo transfer in the blastocyst phase].

    PubMed

    Barrón Vallejo, J; Ortega Díaz, R; Kably Ambe, A

    1999-04-01

    Ectopic pregnancy is a common complication of in vitro fertilization and embryo transfer (IVF-ET). On other hand, heterotopic pregnancy complicates 1-2% of all IVF-ET pregnancies. Tubal damage as reason for treatment and multiple embryo transfer might predispose patients to this complication. We present a successful treated case of an infertile patient that developed simultaneous twin intra- and single extra- uterine pregnancy after blastocyst-stage embryo transfer. In IVF-ET patients presence of an intrauterine gestation not exclude the possibility of a concomitant extrauterine pregnancy. Awareness of the possibility of heterotopic pregnancy after IVF-ET plays an important role in the successful treatment of this reproductive complication. Transfer of good quality embryos can be a risk factor to develop heterotopic pregnancy.

  20. Age, oestradiol and blastocysts can predict success in natural cycle IVF-embryo transfer.

    PubMed

    Tomazevic, T; Korosec, S; Virant Klun, I; Drobnic, S; Verdenik, I

    2007-08-01

    The aim of this study was to evaluate the influence of maternal age and oestradiol concentrations on blastocyst development and live birth rates in natural cycle IVF-embryo transfer. This observational study included 397 natural cycles with IVF embryo transfer for female infertility with embryo transfer on day 5. The cycles were divided into two groups according to the woman's age (<39 and > or = 39 years of age), and into two groups according to oestradiol concentrations on the day of human chorionic gonadotrophin (HCG) administration (0.4-0.49 nmol/l and 0.5-1.2 nmol/l). Comparison between the cycles in younger versus older age groups showed significant differences in blastocyst development rate, live birth rate per embryo transfer and live birth rate per cycle (55 versus 29%, 23 versus 3% and 13 versus 2% respectively) (P < 0.001). Comparison between cycles with lower versus higher oestradiol concentrations showed no significant differences in blastocyst development rate, live birth rate per embryo transfer and live birth rate per cycle (47 versus 49%, 18 versus 18%, and 11 versus 10% respectively). Advanced maternal age negatively predicts the success of natural cycle IVF, while low oestradiol concentrations on the day of HCG administration (ultrasound criteria fulfilled) do not negatively predict blastocyst development and success of natural cycle IVF.

  1. Development of human cloned blastocysts following somatic cell nuclear transfer with adult fibroblasts.

    PubMed

    French, Andrew J; Adams, Catharine A; Anderson, Linda S; Kitchen, John R; Hughes, Marcus R; Wood, Samuel H

    2008-02-01

    Nuclear transfer stem cells hold considerable promise in the field of regenerative medicine and cell-based drug discovery. In this study, a total of 29 oocytes were obtained from three young (20-24 years old) reproductive egg donors who had been successful in previous cycles. These oocytes, deemed by intended parents to be in excess of their reproductive needs, were donated for research without financial compensation by both the egg donor and intended parents after receiving informed consent. All intended parents successfully achieved ongoing pregnancies with the oocytes retained for reproductive purposes. Mature oocytes, obtained within 2 hours following transvaginal aspiration, were enucleated using one of two methods, extrusion or aspiration, after 45 minutes of incubation in cytochalasin B. Rates of oocyte lysis or degeneration did not differ between the two methods. Somatic cell nuclear transfer (SCNT) embryos were constructed using two established adult male fibroblast lines of normal karyotype. High rates of pronuclear formation (66%), early cleavage (47%), and blastocyst (23%) development were observed following incubation in standard in vitro fertilization culture media. One cloned blastocyst was confirmed by DNA and mitochondrial DNA fingerprinting analyses, and DNA fingerprinting of two other cloned blastocysts indicated that they were also generated by SCNT. Blastocysts were also obtained from a limited number of parthenogenetically activated oocytes. This study demonstrates, for the first time, that SCNT can produce human blastocyst-stage embryos using nuclei obtained from differentiated adult cells and provides new information on methods that may be needed for a higher level of efficiency for human nuclear transfer.

  2. Asynchronous fate decisions by single cells collectively ensure consistent lineage composition in the mouse blastocyst

    PubMed Central

    Saiz, Néstor; Williams, Kiah M.; Seshan, Venkatraman E.; Hadjantonakis, Anna-Katerina

    2016-01-01

    Intercellular communication is essential to coordinate the behaviour of individual cells during organismal development. The preimplantation mammalian embryo is a paradigm of tissue self-organization and regulative development; however, the cellular basis of these regulative abilities has not been established. Here we use a quantitative image analysis pipeline to undertake a high-resolution, single-cell level analysis of lineage specification in the inner cell mass (ICM) of the mouse blastocyst. We show that a consistent ratio of epiblast and primitive endoderm lineages is achieved through incremental allocation of cells from a common progenitor pool, and that the lineage composition of the ICM is conserved regardless of its size. Furthermore, timed modulation of the FGF-MAPK pathway shows that individual progenitors commit to either fate asynchronously during blastocyst development. These data indicate that such incremental lineage allocation provides the basis for a tissue size control mechanism that ensures the generation of lineages of appropriate size. PMID:27857135

  3. Vitamin C supplementation enhances compact morulae formation but reduces the hatching blastocyst rate of bovine somatic cell nuclear transfer embryos.

    PubMed

    Li, Qian; Wang, Yong-Sheng; Wang, Li-Jun; Zhang, Hui; Li, Rui-Zhe; Cui, Chen-Chen; Li, Wen-Zhe; Zhang, Yong; Jin, Ya-Ping

    2014-08-01

    Vitamin C, an antioxidant that reduces reactive oxygen species (ROS) in cells, is capable of significantly improving the developmental competence of porcine and mouse somatic cell nuclear transfer (SCNT) embryos, both in vitro and in vivo. In the present study, the effects of vitamin C on the developmental competence of bovine SCNT embryos were investigated. The results indicated that vitamin C (40 μg/mL) positively affected the scavenging of intracellular ROS, cleavage rate at 24 h (76.67 vs. 68.26%, p<0.05), compact morulae formation (60.83 vs. 51.30%, p<0.05), and the blastomere apoptosis index (3.70 ± 1.41 vs. 4.43% ± 1.65, p<0.05) of bovine SCNT embryos. However, vitamin C supplementation did not significantly affect the blastocyst formation rate and proportion of inner cell mass over total cells per blastocyst on day 7. Moreover, vitamin C supplementation obviously impaired the total cell numbers per blastocyst (97.20 ± 11.35 vs. 88.57 ± 10.43, p<0.05) on day 7 and the hatching blastocysts formation rate on day 9 (26.51 vs. 50.65%, p<0.05) compared with that of the untreated group. Vitamin C supplementation preferentially improved the viability of bovine SCNT embryos prior to the blastocyst stage, but did not enhance the formation and quality of blastocysts in vitro. In conclusion, the effect of vitamin C on the development of bovine SCNT embryos is complex, and vitamin C is not a suitable antioxidant chemical for the in vitro culture of bovine SCNT embryos.

  4. Hybrid embryos produced by transferring panda or cat somatic nuclei into rabbit MII oocytes can develop to blastocyst in vitro.

    PubMed

    Wen, Duan-Cheng; Bi, Chun-Ming; Xu, Ying; Yang, Cai-Xia; Zhu, Zi-Yu; Sun, Qing-Yuan; Chen, Da-Yuan

    2005-08-01

    The developmental potential of hybrid embryos produced by transferring panda or cat fibroblasts into nucleated rabbit oocytes was assessed. Both the panda-rabbit and the cat-rabbit hybrid embryos were able to form blastocysts in vitro. However, the rates of attaining the two-cell, four-cell, eight-cell, morula, or blastocyst stages for panda-rabbit hybrids were significantly greater than those of cat-rabbit hybrids (P<0.05). Transferring the rabbit fibroblasts into nucleated rabbit oocytes, 31.0% of the blastocyst rate was obtained, which was significantly higher than that of both the panda-rabbit and the cat-rabbit hybrid embryos (P<0.05). Whether or not the second polar body (PB2) was extruded from the one-cell hybrid embryos (both panda-rabbit and cat-rabbit hybrids) significantly affected their developmental capacity. Embryos without an extruded PB2 showed a higher capacity to develop into blastocysts (panda-rabbit: 19.2%; cat-rabbit: 4.3%), while embryos with extruded PB2 could only develop to the morula stage. The hybrid embryos formed pronucleus-like structures (PN) in 2-4 hr after activation, and the number of PN in one-cell embryos varied from one to five. Tracking of the nucleus in the egg after fusion revealed that the somatic nucleus could approach and aggregate with the oocyte nucleus spontaneously. Chromosome analysis of the panda-rabbit blastocysts showed that the karyotype of the hybrid embryos (2n=86) consisted of chromosomes from both the panda (2n=42) and the rabbit (2n=44). The results demonstrate that (1) it is possible to produce genetic hybrid embryos by interspecies nuclear transfer; (2) the developmental potential of the hybrid embryos is highly correlated to the donor nucleus species; and (3) the hybrid genome is able to support the complete preimplantation embryonic development of the hybrids.

  5. Analysis of embryo morphokinetics, multinucleation and cleavage anomalies using continuous time-lapse monitoring in blastocyst transfer cycles

    PubMed Central

    2014-01-01

    Background Time-lapse imaging combined with embryo morphokinetics may offer a non-invasive means for improving embryo selection. Data from clinics worldwide are necessary to compare and ultimately develop embryo classifications models using kinetic data. The primary objective of this study was to determine if there were kinetic differences between embryos with limited potential and those more often associated with in vitro blastocyst formation and/or implantation. We also wanted to compare putative kinetic markers for embryo selection as proposed by other laboratories to what we were observing in our own laboratory setting. Methods Kinetic data and cycle outcomes were retrospectively analyzed in patients age 39 and younger with 7 or more zygotes cultured in the Embryoscope. Timing of specific events from the point of insemination were determined using time-lapse (TL) imaging. The following kinetic markers were assessed: time to syngamy (tPNf), t2, time to two cells (c), 3c (t3), 4c ( t4), 5c (t5), 8c (t8), morula (tMor), start of blastulation (tSB); tBL, blastocyst (tBL); expanded blastocyst (tEBL). Durations of the second (cc2) and third (cc3) cell cycles, the t5-t2 interval as well as time to complete synchronous divisions s1, s2 and s3 were calculated. Incidence and impact on development of nuclear and cleavage anomalies were also assessed. Results A total of 648 embryos transferred on day 5 were analyzed. The clinical pregnancy and implantation rate were 72% and 50%, respectively. Morphokinetic data showed that tPNf, t2,t4, t8, s1, s2,s3 and cc2 were significantly different in embryos forming blastocysts (ET or frozen) versus those with limited potential either failing to blastulate or else forming poor quality blastocysts ,ultimately discarded. Comparison of embryo kinetics in cycles with all embryos implanting (KID+) versus no implantation (KID-) suggested that markers of embryo competence to implant may be different from ability to form a blastocyst. The

  6. Coasting, embryo development and outcomes of blastocyst transfer: a case-control study.

    PubMed

    Talebi Chahvar, Solmas; Zosmer, Ariel; Caragia, Alina; Balestrini, Simona; Sabatini, Luca; Tranquilli, Andrea Luigi; Al-Shawaf, Talha

    2014-08-01

    This study compared the effect on blastocyst development and clinical outcome of coasting in women at increased risk of moderate-severe ovarian hyperstimulation syndrome (OHSS; n=389) with a control group matched for age and basal FSH that did not undergo coasting (n=386) in IVF/intracytoplasmic sperm injection (ICSI) cycles. The main outcome measures were rate of blastocyst development and live birth. More cycles progressed to the blastocyst stage in the coasted group (n=169) compared with the control group (n=83; 43.4% versus 21.5%; P<0.001). The biochemical pregnancy, clinical pregnancy and live birth rates were similar (46.5% versus 42.0%; 40.6% versus 37.8%; 31.6% versus 30.1%). The duration of coasting up to 4 days did not affect progression to blastocyst stage. The multivariate model showed that coasting (OR 1.73, P=0.004) and the number of oocytes retrieved (OR 1.17, P=0.001) were positively correlated with blastocyst formation. Coasting, a measure to reduce the risk of OHSS, does not impair blastocyst development or clinical outcome. Coasting should remain an effective measure to prevent OHSS.

  7. Forced collapse of the blastocoel enhances survival of cryotop vitrified bovine hatching/hatched blastocysts derived from in vitro fertilization and somatic cell nuclear transfer.

    PubMed

    Min, Sung-Hun; Lee, Enok; Son, Hyeong-Hoon; Yeon, Ji-Yeong; Koo, Deog-Bon

    2013-04-01

    Freezing of bovine blastocysts has been widely used to improve the feasibility of cattle production by the embryo transfer technique. However, the low survival of vitrified-warmed embryos and their further development are crucial problems. Particularly, the production of offspring in vitrified-warmed bovine hatching/hatched blastocysts derived from in vitro fertilization (IVF) and somatic cell nuclear transfer (SCNT) is very low. Thus, we examined the effects of forced blastocoel collapse (FBC) before vitrification of bovine IVF- and SCNT-derived hatching/hatched embryos on the survival rate and apoptosis index after warming. Under optimal conditions, the overall survival rates in vitrified-warmed bovine IVF- and SCNT-derived hatching/hatched blastocysts were higher in FBC groups than in non-FBC groups (p<0.05). The total cell numbers of vitrified-warmed hatching/hatched blastocysts were higher in FBC groups than in non-FBC groups (p<0.05). Otherwise, the number of apoptotic positive cells of vitrified-warmed hatching/hatched blastocysts was lower in FBC groups than in non-FBC groups (p<0.05). Taken together, these findings suggest that forced collapse of the blastocoel using a pulled Pasteur pipette is an effective pretreatment technique for vitrification of bovine IVF- and SCNT-derived hatching/hatched blastocysts.

  8. Improved blastocyst development of single cow OPU-derived presumptive zygotes by group culture with agarose-embedded helper embryos

    PubMed Central

    2011-01-01

    Background The in vitro culture of presumed zygotes derived from single cow ovum pick-up (OPU) is important for the production of quality blastocysts maintaining pedigree. The aim of the present study was to evaluate the agar chip-embedded helper embryo coculture system for single cow OPU-derived zygotes by assessing embryo quality. Methods Cumulus oocyte complexes (COCs) were collected from Hanwoo cows with high genetic merit twice a week using the ultra-sound guided OPU technique and from slaughterhouse ovaries. The Hanwoo cow COCs and slaughterhouse ovaries were matured in vitro, fertilized in vitro with thawed Hanwoo sperm and cultured for 24 h. The presumed zygotes were subsequently placed in three different culture systems: (1) control OPU (controlOPU) with single cow OPU-derived presumed zygotes (2~8); (2) agar chip-embedded slaughterhouse helper embryo coculture (agarOPU) with ten presumed zygotes including all presumed zygotes from a cow (2~8) and the rest from agar chip-embedded slaughterhouse presumed zygotes (8~2); and (3) slaughterhouse in vitro embryo production (sIVP) with ten slaughterhouse ovary-derived presumed zygotes, each in 50 μL droplets. Day 8 blastocysts were assayed for apoptosis and gene expression using real time PCR. Results The coculture system promoted higher blastocyst development in OPU zygotes compared to control OPU zygotes cultured alone (35.2 vs. 13.9%; P < 0.01). Genes predicted to be involved in implantation failure and/or embryo resorption were down-regulated (P < 0.05) in control OPU zygotes (CD9, 0.4-fold; AKRAB1, 0.3-fold) and in cocultured zygotes (CD9, 0.3-fold; AKRAB1, 0.3-fold) compared to sIVP blastocysts (1.0-fold). Moreover, genes involved in implantation and/or normal calf delivery were up-regulated (P < 0.05 to P < 0.01) in control OPU zygotes (PGSH2, 5.0-fold; TXN, 4.3-fold; PLAU, 1.7-fold) and cocultured zygotes (PGSH2, 14.5-fold; TXN, 3.2-fold; PLAU, 6.8-fold) compared to sIVP (1.0-fold) blastocysts. However

  9. Effect of sperm DNA fragmentation on clinical outcome of frozen-thawed embryo transfer and on blastocyst formation.

    PubMed

    Ni, Wuhua; Xiao, Shiquan; Qiu, Xiufang; Jin, Jianyuan; Pan, Chengshuang; Li, Yan; Fei, Qianjin; Yang, Xu; Zhang, Liya; Huang, Xuefeng

    2014-01-01

    During the last decades, many studies have shown the possible influence of sperm DNA fragmentation on assisted reproductive technique outcomes. However, little is known about the impact of sperm DNA fragmentation on the clinical outcome of frozen-thawed embryo transfer (FET) from cycles of conventional in vitro fertilization (IVF) and intra-cytoplasmic sperm injection (ICSI). In the present study, the relationship between sperm DNA fragmentation (SDF) and FET clinical outcomes in IVF and ICSI cycles was analyzed. A total of 1082 FET cycles with cleavage stage embryos (C-FET) (855 from IVF and 227 from ICSI) and 653 frozen-thawed blastocyst transfer cycles (B-FET) (525 from IVF and 128 from ICSI) were included. There was no significant change in clinical pregnancy, biochemical pregnancy and miscarriage rates in the group with a SDF >30% compared with the group with a SDF ≤30% in IVF and ICSI cycles with C-FET or B-FET. Also, there was no significant impact on the FET clinic outcome in IVF and ICSI when different values of SDF (such as 10%, 20%, 25%, 35%, and 40%) were taken as proposed threshold levels. However, the blastulation rates were significantly higher in the SDF ≤30% group in ICSI cycle. Taken together, our data show that sperm DNA fragmentation measured by Sperm Chromatin Dispersion (SCD) test is not associated with clinical outcome of FET in IVF and ICSI. Nonetheless, SDF is related to the blastocyst formation in ICSI cycles.

  10. Comparing spatial expression dynamics of bovine blastocyst under three different procedures: in-vivo, in-vitro derived, and somatic cell nuclear transfer embryos.

    PubMed

    Nagatomo, Hiroaki; Akizawa, Hiroki; Sada, Ayari; Kishi, Yasunori; Yamanaka, Ken-ichi; Takuma, Tetsuya; Sasaki, Keisuke; Yamauchi, Nobuhiko; Yanagawa, Yojiro; Nagano, Masashi; Kono, Tomohiro; Takahashi, Masashi; Kawahara, Manabu

    2015-11-01

    There has been no work on spatiotemporal transcriptomic differences of blastocysts using in vivo- and in vitro-derived, and somatic cell nuclear transfer (SCNT) embryos. Here, we first compared the lineage-differentially transcriptomic profiles of in vivo- and in vitro-derived embryos by microarray analysis using divided into inner cell mass (ICM)-and trophectoderm (TE)-side samples, as well as those derived from SCNT in order to explore lineage-differentially expressed genes that are associated with preimplantation development in cattle. The transcriptomic profiles of the ICM-specific and TE-specific genes were similar between in vitro-derived embryos and in vivo-derived embryos, whereas SCNT embryos exhibited unusual lineage-differentially gene expression regulation at the blastocyst stage. The genes expressed in a spatiotemporal manner between developmentally normal in-vivo derived blastocysts and developmentally abnormal SCNT blastocysts might play critical roles for preimplantation development. Comparing spatial expression dynamics of bovine blastocyst under three different procedures revealed that CIITA was expressed in ICM-side samples of all the embryo types. CIITA is known as the master regulator of major histocompatibility complexes (MHC) class II genes that express in antigen-presenting cells but its biological function in preimplantation embryo is still unknown in mammals. Knockdown of CIITA expression in in vitro-derived embryos did not affect cleavage, but disrupted development of embryos into the blastocyst stage. These findings provide the novel transcriptomic information on blastocyst formation, raising the possibility that immune function-related gene directly plays important roles in bovine preimplantation development.

  11. Successful vitrification of bovine blastocysts on paper container.

    PubMed

    Kim, Y M; Uhm, S J; Gupta, M K; Yang, J S; Lim, J-G; Das, Z C; Heo, Y T; Chung, H-J; Kong, I-K; Kim, N-H; Lee, H T; Ko, D H

    2012-09-15

    Cryopreservation of bovine embryos can be performed by a variety of methods with variable degree of success. Here, we report a new, easy to perform, simple, inexpensive, and successful method for vitrification of bovine blastocysts. In vitro produced bovine blastocysts were exposed to vitrification solution (5.5 m ethylene glycol, 10% serum and 1% sucrose) in one single step for 20 s, loaded on a paper container prepared from commonly available non-slippery, absorbent writing paper, and then were directly plunged into liquid nitrogen for storage. Vitrified blastocysts were warmed by serial rinsing in 0.5, 0.25 and 0.125 m sucrose solution for 1 min each. Results showed that one step exposure of bovine blastocysts to cryoprotective agents was sufficient to achieve successful cryopreservation. Under these conditions, more than 95% of blastocysts survived the vitrification-warming on paper containers which was significantly higher than those obtained from other containers, such as electron microscope (EM) grid (78.1%), open pulled straw (OPS; 80.2%), cryoloop (76.2%) or plastic straw (73.9%). Embryo transfer of blastocysts vitrified-warmed on paper container resulted in successful conception (19.3%) and full-term live birth of offspring (12.3%) which were lower (P < 0.05) than those obtained from non-vitrified blastocysts (38.0 and 32.7%) but were comparable (P > 0.05) to those obtained from blastocysts vitrified-warmed on EM grid (23.3 and 14.2%). Our results, therefore, suggest that paper may be an inexpensive and useful container for the cryopreservation of animal embryos.

  12. An Earlier Uterine Environment Favors the In Vivo Development of Fresh Pig Morulae and Blastocysts Transferred by a Nonsurgical Deep-uterine Method

    PubMed Central

    ANGEL, Miguel Angel; GIL, Maria Antonia; CUELLO, Cristina; SANCHEZ-OSORIO, Jonatan; GOMIS, Jesus; PARRILLA, Inmaculada; VILA, Jordi; COLINA, Ignacio; DIAZ, Marta; REIXACH, Josep; VAZQUEZ, Jose Luis; VAZQUEZ, Juan Maria; ROCA, Jordi; MARTINEZ, Emilio A.

    2014-01-01

    This study aimed to evaluate the effect of recipient-donor estrous cycle synchrony on recipient reproductive performance after nonsurgical deep-uterine (NsDU) embryo transfer (ET). The transfers (N=132) were conducted in recipients sows that started estrus 24 h before (–24 h; N=9) or 0 h (synchronous; N=31), 24 h (+24 h; N=74) or 48 h (+48 h; N=18) after the donors. A total of 30 day 5 morulae or day 6 blastocysts (day 0=onset of estrus) were transferred per recipient. The highest farrowing rates (FRs) were achieved when estrus appeared in recipients 24 h later than that in the donors (81.1%), regardless of the embryonic stage used for the transfers. The FR notably decreased (P<0.05) when recipients were –24 h asynchronous (0%), synchronous (61.3%) or +48 h asynchronous (50%) relative to the donors. No differences in litter size (LS) and piglet birth weights were observed among the synchronous and +24 h or +48 h asynchronous groups. While a +24 h asynchronous recipient was suitable for transfers performed with either morulae (FR, 74.3%; LS, 9.2 ± 0.6 piglets) or blastocysts (FR, 84.6%; LS, 9.8 ± 0.6 piglets), a + 48 h asynchronous recipient was adequate for blastocysts (FR, 87.5%; LS, 10.4 ± 0.7 piglets) but not for morulae (FR, 30.0%; LS, 7.3 ± 2.3 piglets). In conclusion, this study confirms the effectiveness of the NsDU-ET technology and shows that porcine embryos tolerate better a less advanced uterine environment if they are nonsurgically transferred deep into the uterine horn. PMID:25030061

  13. Passage number of porcine embryonic germ cells affects epigenetic status and blastocyst rate following somatic cell nuclear transfer.

    PubMed

    Li, Juan; Gao, Yu; Petkov, Stoyan; Purup, Stig; Hyttel, Poul; Callesen, Henrik

    2014-06-10

    Epigenetic instability of donor cells due to long-term in vitro culture may influence the success rate of subsequent somatic cell nuclear transfer (SCNT). Therefore, the present study was designed (1) to investigate the epigenetic changes after prolonged culture in vitro of porcine embryonic germ (EG) cells, including differences in expression levels of both DNA methylation and demethylation-related genes and catalyses of histone modifications, and (2) to assess the efficiency of SCNT using EG cells from different passages. Results showed that genes either associated with DNA demethylation including DNMTs and TET1 or genes related to histone acetylation including HDACs were highly expressed in EG cells at higher passages when compared to EG cells at lower passages. In addition, the expression level of H3K27me3 functional methylase EZH2 increased while no changes were observed on H3K27me3 demethylase JMJD3 in relation to passage number. Moreover, the expression levels of both the H3K4me3 methylase MLL1 and the H3K4me3 demethylase RBP2 were increased at high passages. By using lower passage (numbers 3-5) EG cells as donor cells, the SCNT efficiency was significantly lower compared with use of fetal fibroblast donor cells. However, similar blastocyst rates were achieved when using higher passage (numbers 9-12) EG cells as donor cells. In conclusion, the present study suggests that the epigenetic status of EG cells change with increasing passage numbers, and that higher passage number EG cells are better primed for SCNT.

  14. Selection of competent blastocysts for transfer by combining time-lapse monitoring and array CGH testing for patients undergoing preimplantation genetic screening: a prospective study with sibling oocytes

    PubMed Central

    2014-01-01

    Background Recent advances in time-lapse monitoring in IVF treatment have provided new morphokinetic markers for embryonic competence. However, there is still very limited information about the relationship between morphokinetic parameters, chromosomal compositions and implantation potential. Accordingly, this study aimed at investigating the effects of selecting competent blastocysts for transfer by combining time-lapse monitoring and array CGH testing on pregnancy and implantation outcomes for patients undergoing preimplantation genetic screening (PGS). Methods A total of 1163 metaphase II (MII) oocytes were retrieved from 138 PGS patients at a mean age of 36.6 ± 2.4 years. These sibling MII oocytes were then randomized into two groups after ICSI: 1) Group A, oocytes (n = 582) were cultured in the time-lapse system and 2) Group B, oocytes (n = 581) were cultured in the conventional incubator. For both groups, whole genomic amplification and array CGH testing were performed after trophectoderm biopsy on day 5. One to two euploid blastocysts within the most predictive morphokinetic parameters (Group A) or with the best morphological grade available (Group B) were selected for transfer to individual patients on day 6. Ongoing pregnancy and implantation rates were compared between the two groups. Results There were significant differences in clinical pregnancy rates between Group A and Group B (71.1% vs. 45.9%, respectively, p = 0.037). The observed implantation rate per embryo transfer significantly increased in Group A compared to Group B (66.2% vs. 42.4%, respectively, p = 0.011). Moreover, a significant increase in ongoing pregnancy rates was also observed in Group A compared to Group B (68.9% vs. 40.5%. respectively, p = 0.019). However, there was no significant difference in miscarriage rate between the time-lapse system and the conventional incubator (3.1% vs. 11.8%, respectively, p = 0.273). Conclusions This is the first prospective investigation using

  15. Defining the three cell lineages of the human blastocyst by single-cell RNA-seq

    PubMed Central

    Blakeley, Paul; Fogarty, Norah M. E.; del Valle, Ignacio; Wamaitha, Sissy E.; Hu, Tim Xiaoming; Elder, Kay; Snell, Philip; Christie, Leila; Robson, Paul; Niakan, Kathy K.

    2015-01-01

    Here, we provide fundamental insights into early human development by single-cell RNA-sequencing of human and mouse preimplantation embryos. We elucidate conserved transcriptional programs along with those that are human specific. Importantly, we validate our RNA-sequencing findings at the protein level, which further reveals differences in human and mouse embryo gene expression. For example, we identify several genes exclusively expressed in the human pluripotent epiblast, including the transcription factor KLF17. Key components of the TGF-β signalling pathway, including NODAL, GDF3, TGFBR1/ALK5, LEFTY1, SMAD2, SMAD4 and TDGF1, are also enriched in the human epiblast. Intriguingly, inhibition of TGF-β signalling abrogates NANOG expression in human epiblast cells, consistent with a requirement for this pathway in pluripotency. Although the key trophectoderm factors Id2, Elf5 and Eomes are exclusively localized to this lineage in the mouse, the human orthologues are either absent or expressed in alternative lineages. Importantly, we also identify genes with conserved expression dynamics, including Foxa2/FOXA2, which we show is restricted to the primitive endoderm in both human and mouse embryos. Comparison of the human epiblast to existing embryonic stem cells (hESCs) reveals conservation of pluripotency but also additional pathways more enriched in hESCs. Our analysis highlights significant differences in human preimplantation development compared with mouse and provides a molecular blueprint to understand human embryogenesis and its relationship to stem cells. PMID:26293300

  16. Defining the three cell lineages of the human blastocyst by single-cell RNA-seq.

    PubMed

    Blakeley, Paul; Fogarty, Norah M E; del Valle, Ignacio; Wamaitha, Sissy E; Hu, Tim Xiaoming; Elder, Kay; Snell, Philip; Christie, Leila; Robson, Paul; Niakan, Kathy K

    2015-09-15

    Here, we provide fundamental insights into early human development by single-cell RNA-sequencing of human and mouse preimplantation embryos. We elucidate conserved transcriptional programs along with those that are human specific. Importantly, we validate our RNA-sequencing findings at the protein level, which further reveals differences in human and mouse embryo gene expression. For example, we identify several genes exclusively expressed in the human pluripotent epiblast, including the transcription factor KLF17. Key components of the TGF-β signalling pathway, including NODAL, GDF3, TGFBR1/ALK5, LEFTY1, SMAD2, SMAD4 and TDGF1, are also enriched in the human epiblast. Intriguingly, inhibition of TGF-β signalling abrogates NANOG expression in human epiblast cells, consistent with a requirement for this pathway in pluripotency. Although the key trophectoderm factors Id2, Elf5 and Eomes are exclusively localized to this lineage in the mouse, the human orthologues are either absent or expressed in alternative lineages. Importantly, we also identify genes with conserved expression dynamics, including Foxa2/FOXA2, which we show is restricted to the primitive endoderm in both human and mouse embryos. Comparison of the human epiblast to existing embryonic stem cells (hESCs) reveals conservation of pluripotency but also additional pathways more enriched in hESCs. Our analysis highlights significant differences in human preimplantation development compared with mouse and provides a molecular blueprint to understand human embryogenesis and its relationship to stem cells.

  17. Vitrification of human blastocysts: an update.

    PubMed

    Liebermann, Juergen

    2009-01-01

    Transfer of blastocyst-stage embryos has been shown to increase pregnancy rates while allowing for improved selection of potentially viable embryos. At this late stage of development, lower numbers of embryos can be transferred, resulting in less high-order multiple pregnancies and increased implantation rates. Between January 2004 and February 2009, 8449 blastocysts from 2453 patients were vitrified. After 1398 vitrified embryo transfers (VET) of both day-5 and day-6 blastocysts with a mean patient age of 34.6 +/- 5.0 years, the study centre has seen a survival rate of 96.3% (2730/2835), an implantation rate of 29.4% and a clinical pregnancy rate per VET of 42.8% (599 pregnancies/1398 warmed embryo transfers). After more than 5 years of vitrifying blastocysts, the perinatal outcome was, from 348 deliveries with vitrified blastocysts, the births of 431 babies (202 boys and 229 girls). One of the benefits of blastocyst vitrification is that it can be undertaken on a more flexible basis by laboratory staff. Also, vitrification may allow individual blastocysts to be cryopreserved at their optimal stage of development and expansion.

  18. Cytokines and Blastocyst Hatching.

    PubMed

    Seshagiri, Polani B; Vani, Venkatappa; Madhulika, Pathak

    2016-03-01

    Blastocyst implantation into the uterine endometrium establishes early pregnancy. This event is regulated by blastocyst- and/or endometrium-derived molecular factors which include hormones, growth factors, cell adhesion molecules, cytokines and proteases. Their coordinated expression and function are critical for a viable pregnancy. A rate-limiting event that immediately precedes implantation is the hatching of blastocyst. Ironically, blastocyst hatching is tacitly linked to peri-implantation events, although it is a distinct developmental phenomenon. The exact molecular network regulating hatching is still unclear. A number of implantation-associated molecular factors are expressed in the pre-implanting blastocyst. Among others, cytokines, expressed by peri-implantation blastocysts, are thought to be important for hatching, making blastocysts implantation competent. Pro-inflammatory (IL-6, LIF, GM-CSF) and anti-inflammatory (IL-11, CSF-1) cytokines improve hatching rates; they modulate proteases (MMPs, tPAs, cathepsins and ISP1). However, functional involvement of cytokines and their specific mediation of hatching-associated proteases are unclear. There is a need to understand mechanistic roles of cytokines and proteases in blastocyst hatching. This review will assess the available knowledge on blastocyst-derived pro-inflammatory and anti-inflammatory cytokines and their role in potentially regulating blastocyst hatching. They have implications in our understanding of early embryonic loss and infertility in mammals, including humans.

  19. Outcomes of trophectoderm biopsy on cryopreserved blastocysts: a case series.

    PubMed

    Lathi, Ruth B; Massie, Jamie A M; Gilani, Morgan; Milki, Amin A; Westphal, Lynn M; Baker, Valerie L; Behr, Barry

    2012-11-01

    Preimplantation genetic diagnosis (PGD) is an increasingly common adjunct to IVF. The information gained from PGD may be used to reduce the incidence of chromosomally abnormal pregnancies and augment the current selection process of embryos. As such, patients may choose to utilize PGD in either fresh or cryopreserved IVF cycles. It is a common practice to cryopreserve excess embryos at the blastocyst stage. In these cases, trophectoderm biopsy is the only technique available for PGD. This articles reports this study centre's experience with trophectoderm biopsies of cryopreserved blastocysts in 12 patients who underwent 13 cycles of PGD. The implantation rate per embryo transferred was 46% and the ongoing pregnancy rate per embryo transfer was 63%. The results from this case series demonstrate that trophectoderm biopsy on cryopreserved blastocysts to perform PGD is logistically feasible. In addition, the rate of implantation and ongoing pregnancy were maintained within a reasonable range to justify the procedure. Preimplantation genetic diagnosis (PGD) is an increasingly common adjunct to IVF and is used to evaluate the genetic makeup of the embryo prior to transfer of the embryo into the uterus. The information gained from PGD may be used to identify single-gene disorders that result in genetic disease, reduce the incidence of chromosomally abnormal pregnancies and/or augment the selection process of embryos to be transferred. In order to perform PGD, a biopsy of the embryo is the performed and cells are removed for testing. PGD may be performed in either fresh or frozen (cryopreserved) IVF cycles. Patients who have cryopreserved embryos remaining in storage from a previous fresh cycle may wish to have these embryos tested with PGD. Many embryos are frozen on day 5 of development, referred to as the blastocyst stage. At this stage of development, embryo biopsy is performed via a technique known as 'trophectoderm biopsy', in which 1-3 of the cells destined to

  20. The mammalian blastocyst.

    PubMed

    Frankenberg, Stephen R; de Barros, Flavia R O; Rossant, Janet; Renfree, Marilyn B

    2016-01-01

    The blastocyst is a mammalian invention that carries the embryo from cleavage to gastrulation. For such a simple structure, it exhibits remarkable diversity in its mode of formation, morphology, longevity, and intimacy with the uterine endometrium. This review explores this diversity in the light of the evolution of viviparity, comparing the three main groups of mammals: monotremes, marsupials, and eutherians. The principal drivers in blastocyst evolution were loss of yolk coupled with evolution of the placenta. An important outcome of blastocyst development is differentiation of two extraembryonic lineages (trophoblast and hypoblast) that contribute to the placenta. While in many species trophoblast segregation is often coupled with blastocyst formation, in marsupials and at least some Afrotherians, these events do not coincide. Thus, many questions regarding the conservation of molecular mechanisms controlling these events are of great interest but currently unresolved. For further resources related to this article, please visit the WIREs website.

  1. Implantation of fresh and thawed-warmed embryos in single embryo transfer cycles: interpreting the initial beta-HCG.

    PubMed

    Sites, Cynthia K; St Marie, Peter; Rahil, Tayyab

    2015-03-01

    Little is known about the effects of human embryo cryopreservation on developmental potential. Initial beta-HCG, indicating embryo implantation, was measured in 322 single embryo transfer cycles (246 fresh and 76 thawed-warmed). Median initial beta-HCG was higher for fresh compared with thawed-warmed transfers (126 versus 100 mIU/ml; P = 0.04). Blastocyst slow cooling resulted in a lower initial beta-HCG compared with vitrification (P = 0.01). Live birth rates were lower for blastocyst slow cooling (25%) compared with vitrification (71%) and fresh transfer (70%). We conclude that cryopreservation may impair an embryo's ability to produce beta-HCG, but that vitrification does not impair developmental potential.

  2. Autologous embryo-cumulus cells co-culture and blastocyst transfer in repeated implantation failures: a collaborative prospective randomized study.

    PubMed

    Benkhalifa, M; Demirol, A; Sari, T; Balashova, E; Tsouroupaki, M; Giakoumakis, Y; Gurgan, T

    2012-05-01

    In repeated implantation failure, the co-culture of human embryos with somatic cells has been reported to promote the improvement of embryos quality, implantation and pregnancy rate. It was reported that feeder cells can be more beneficial to the oocyte and embryo by detoxifying the culture medium and supporting embryo development via different pathways. In this study, 432 patients, each with a minimum of three repeated implantation failures, were accepted for a prospective randomized study with or without autologous cumulus cell embryo co-culture and transfer at day 3 or day 5-6. We also investigated the expression of leukaemia inhibitor factor (LIF) and platelet activating factor receptor (PAF-R) on day 3 confluent cumulus cells. The statistic analysis of the data showed significant difference of implantation and clinical pregnancy rates between classical culture and day 3 compared with co-culture and day 5-6 transfer. The molecular analysis showed that cumulus cells express the LIF and the PAF-R genes and confirmed the possible positive role of growth factors and cytokines in early embryo development. Embryo co-culture systems with autologous cells can be beneficial in routine in vitro fertilization for embryo selection and implantation improvement. More molecular investigations need to be done to improve elucidation of the complex dialogue between the embryo and feeder cells prior to implantation and to understand the involved biological function and molecular process during embryo development.

  3. Transcriptome Analysis of Pig In Vivo, In Vitro–Fertilized, and Nuclear Transfer Blastocyst-Stage Embryos Treated with Histone Deacetylase Inhibitors Postfusion and Activation Reveals Changes in the Lysosomal Pathway

    PubMed Central

    Whitworth, Kristin M.; Mao, Jiude; Lee, Kiho; Spollen, William G.; Samuel, Melissa S.; Walters, Eric M.; Spate, Lee D.

    2015-01-01

    Abstract Genetically modified pigs are commonly created via somatic cell nuclear transfer (SCNT). Treatment of reconstructed embryos with histone deacetylase inhibitors (HDACi) immediately after activation improves cloning efficiency. The objective of this experiment was to evaluate the transcriptome of SCNT embryos treated with suberoylanilide hydroxamic acid (SAHA), 4-iodo-SAHA (ISAHA), or Scriptaid as compared to untreated SCNT, in vitro–fertilized (IVF), and in vivo (IVV) blastocyst-stage embryos. SAHA (10 μM) had the highest level of blastocyst development at 43.9%, and all treatments except 10 μM ISAHA had the same percentage of blastocyst development as Scriptaid (p<0.05). Two treatments, 1.0 μM ISAHA and 1.0 μM SAHA, had higher mean cell number than No HDACi treatment (p<0.021). Embryo transfers performed with 10 μM SAHA- and 1 μM ISAHA-treated embryos resulted in the birth of healthy piglets. GenBank accession numbers from up- and downregulated transcripts were loaded into the Database for Annotation, Visualization and Integrated Discovery to identify enriched biological themes. HDACi treatment yielded the highest enrichment for transcripts within the Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway, lysosome. The mean intensity of LysoTracker was lower in IVV embryos compared to IVF and SCNT embryos (p<0.0001). SAHA and ISAHA can successfully be used to create healthy piglets from SCNT. PMID:26731590

  4. Transcriptome Analysis of Pig In Vivo, In Vitro-Fertilized, and Nuclear Transfer Blastocyst-Stage Embryos Treated with Histone Deacetylase Inhibitors Postfusion and Activation Reveals Changes in the Lysosomal Pathway.

    PubMed

    Whitworth, Kristin M; Mao, Jiude; Lee, Kiho; Spollen, William G; Samuel, Melissa S; Walters, Eric M; Spate, Lee D; Prather, Randall S

    2015-08-01

    Genetically modified pigs are commonly created via somatic cell nuclear transfer (SCNT). Treatment of reconstructed embryos with histone deacetylase inhibitors (HDACi) immediately after activation improves cloning efficiency. The objective of this experiment was to evaluate the transcriptome of SCNT embryos treated with suberoylanilide hydroxamic acid (SAHA), 4-iodo-SAHA (ISAHA), or Scriptaid as compared to untreated SCNT, in vitro-fertilized (IVF), and in vivo (IVV) blastocyst-stage embryos. SAHA (10 μM) had the highest level of blastocyst development at 43.9%, and all treatments except 10 μM ISAHA had the same percentage of blastocyst development as Scriptaid (p<0.05). Two treatments, 1.0 μM ISAHA and 1.0 μM SAHA, had higher mean cell number than No HDACi treatment (p<0.021). Embryo transfers performed with 10 μM SAHA- and 1 μM ISAHA-treated embryos resulted in the birth of healthy piglets. GenBank accession numbers from up- and downregulated transcripts were loaded into the Database for Annotation, Visualization and Integrated Discovery to identify enriched biological themes. HDACi treatment yielded the highest enrichment for transcripts within the Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway, lysosome. The mean intensity of LysoTracker was lower in IVV embryos compared to IVF and SCNT embryos (p<0.0001). SAHA and ISAHA can successfully be used to create healthy piglets from SCNT.

  5. Transcriptome analyses of inner cell mass and trophectoderm cells isolated by magnetic-activated cell sorting from bovine blastocysts using single cell RNA-seq.

    PubMed

    Zhao, X-M; Cui, L-S; Hao, H-S; Wang, H-Y; Zhao, S-J; Du, W-H; Wang, D; Liu, Y; Zhu, H-B

    2016-10-01

    Research on bovine embryonic stem cells (bESCs) has been hampered because bESCs are cultured in conditions that are based on information obtained from culturing mouse and human inner cell mass (ICM) cells. The aim of this study was to compare gene expression in ICM and trophectoderm (TE) cell lineages of bovine embryos and to discuss the findings relative to information available for mice and humans. We separated a high-purity (>90%) ICM and TE from bovine blastocysts by magnetic-activated cell sorting and analysed their transcriptomes by single cell RNA-seq. Differentially expressed genes (DEGs) were assessed using Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) databases. Finally, qRT-PCR was performed to validate the RNA-seq results. From 207 DEGs identified (adjusted p ≤ .05; fold change ≥2), 159 and 48 had greater expression in the ICM and TE cells respectively. We validated 27 genes using qRT-PCR and found their expression patterns were mostly similar to those of RNA-seq, including 12 novel ICM-dominant (HNF4A, CCL24, FGFR4, IFITM3, PTCHD2, GJB5, FN1, KLK7, PRDM14, GRP, FGF19 and GCM1) and two novel TE-dominant (SLC10A1 and WNT4) genes. Bioinformatics analysis showed that these DEGs are involved in many important pathways, such as MAPK and cancer cell pathways, and these pathways have been shown to play essential roles in mouse and human ESCs in the self-renewal and pluripotent maintenance. As a conclusion, there were sufficient differences to allow us to conclude that the control of pluripotency in bovine ICM cells is species-specific.

  6. Heat shock decreases the embryonic quality of frozen-thawed bovine blastocysts produced in vitro

    PubMed Central

    MORI, Miyuki; HAYASHI, Takeshi; ISOZAKI, Yoshihiro; TAKENOUCHI, Naoki; SAKATANI, Miki

    2015-01-01

    In this study, the effect of heat shock on frozen-thawed blastocysts was evaluated using in vitro-produced (IVP) bovine embryos. In experiment 1, the effects of 6 h of heat shock at 41.0 C on fresh blastocysts were evaluated. HSPA1A expression as a reflection of stress was increased by heat shock (P < 0.05), but the expressions of the quality markers IFNT and POU5F1 were not affected. In experiment 2, frozen-thawed blastocysts were incubated at 38.5 C for 6 h (cryo-con) or exposed to heat shock at 41.0 C for 6 h (cryo-HS). Then, blastocysts were cultured at 38.5 C until 48 h after thawing (both conditions). Cryo-HS blastocysts exhibited a decreased recovery rate: HSPA1A expression was dramatically increased compared with that in fresh or cryo-con blastocysts at 6 h, and IFNT expression was decreased compared with that in cryo-con blastocysts at 6 h (both P < 0.05). Cryo-con blastocysts at 6 h also exhibited higher HSPA1A expression than fresh blastocysts (P < 0.05). At 48 h after thawing, the number of hatched blastocysts and blastocyst diameter were lower in cryo-HS blastocysts (P < 0.05). Cryo-con blastocysts showed lower POU5F1 levels at 48 h than fresh, cryo-con or cryo-HS blastocysts at 6 h (P < 0.05), but their POU5F1 levels were not different from those of cryo-HS blastocysts at 48 h. These results indicated that application of heat shock to frozen-thawed blastocysts was highly damaging. The increase in damage by the interaction of freezing-thawing and heat shock might be one reason for the low conception rate in frozen-thawed embryo transfer in summer. PMID:26096768

  7. Heat shock decreases the embryonic quality of frozen-thawed bovine blastocysts produced in vitro.

    PubMed

    Mori, Miyuki; Hayashi, Takeshi; Isozaki, Yoshihiro; Takenouchi, Naoki; Sakatani, Miki

    2015-01-01

    In this study, the effect of heat shock on frozen-thawed blastocysts was evaluated using in vitro-produced (IVP) bovine embryos. In experiment 1, the effects of 6 h of heat shock at 41.0 C on fresh blastocysts were evaluated. HSPA1A expression as a reflection of stress was increased by heat shock (P < 0.05), but the expressions of the quality markers IFNT and POU5F1 were not affected. In experiment 2, frozen-thawed blastocysts were incubated at 38.5 C for 6 h (cryo-con) or exposed to heat shock at 41.0 C for 6 h (cryo-HS). Then, blastocysts were cultured at 38.5 C until 48 h after thawing (both conditions). Cryo-HS blastocysts exhibited a decreased recovery rate: HSPA1A expression was dramatically increased compared with that in fresh or cryo-con blastocysts at 6 h, and IFNT expression was decreased compared with that in cryo-con blastocysts at 6 h (both P < 0.05). Cryo-con blastocysts at 6 h also exhibited higher HSPA1A expression than fresh blastocysts (P < 0.05). At 48 h after thawing, the number of hatched blastocysts and blastocyst diameter were lower in cryo-HS blastocysts (P < 0.05). Cryo-con blastocysts showed lower POU5F1 levels at 48 h than fresh, cryo-con or cryo-HS blastocysts at 6 h (P < 0.05), but their POU5F1 levels were not different from those of cryo-HS blastocysts at 48 h. These results indicated that application of heat shock to frozen-thawed blastocysts was highly damaging. The increase in damage by the interaction of freezing-thawing and heat shock might be one reason for the low conception rate in frozen-thawed embryo transfer in summer.

  8. Blastocyst culture and cryopreservation to optimize clinical outcomes of warming cycles.

    PubMed

    Zhu, Lixia; Xi, Qingsong; Zhang, Hanwang; Li, Yufeng; Ai, Jihui; Jin, Lei

    2013-08-01

    Surplus embryos available for cryopreservation in fresh cycles are considered as having good potential for future use. However, the optimal stage of embryo cryopreservation remains unclear. In this study, 1190 patients with surplus embryos on day 3 were divided into two groups: cleavage-stage embryo cryopreservation (control group) and blastocyst cryopreservation (blastocyst group). The clinical outcomes of the subsequent warming cycles were evaluated. The proportion of cycles with blastocyst formation was 73.8% in the blastocyst group. Although in the blastocyst group, the cancellation rate of blastocyst transfer was increased due to lack of blastocysts available for cryopreservation, the blastocyst group achieved significantly higher rates of clinical pregnancy/cycle (43.2% versus 34.9%; P=0.003), pregnancy/transfer (59.5% versus 35.4%; P<0.001) and implantation (46.5% versus 22.2%; P<0.001) from the first warming cycle compared with the control group. In an embryo-number classified analysis, the clinical pregnancy rate was also higher in the blastocyst group. However, the cumulative pregnancy was similar between the two groups. Blastocyst culture as an embryo selection tool will not improve embryo viability but it will help patients to achieve pregnancy more quickly. Extended culture of surplus embryos to the blastocyst stage for cryopreservation optimizes the clinical outcomes.

  9. A clinically useful simplified blastocyst grading system.

    PubMed

    Richardson, Alison; Brearley, Sophie; Ahitan, Saran; Chamberlain, Sarah; Davey, Tracey; Zujovic, Lyndsey; Hopkisson, James; Campbell, Bruce; Raine-Fenning, Nick

    2015-10-01

    The aim of this study was to investigate whether a new simplified blastocyst grading system (A: fully expanded, clear inner cell mass, cohesive trophectoderm; B: not yet expanded, clear inner cell mass, cohesive trophectoderm; C: small inner cell mass ± irregular trophectoderm ± excluded/degenerate cells) was clinically useful. All day-5 single embryo transfers between 15 June 2009 and 29 June 2012 were reviewed. Implantation, clinical pregnancy and live birth rates were related to embryo quality. Five embryologists were asked to grade and decide the clinical fate of 80 images of day-5 embryos on two occasions 4-6 weeks apart. Implantation, clinical pregnancy and live birth rates decreased with deteriorating embryo quality. A highly significant (P < 0.01) difference was observed between the groups. Inter-observer agreement was substantial for grade allocation (K = 0.63) and clinical decision-making (K = 0.66). Intra-observer agreement ranged from substantial (K = 0.71) to almost perfect (K = 0.88) for grade allocation, and was almost perfect for clinical fate determination (K ≥ 0.84). This grading system is quick and easy to use, effectively predicts IVF outcome and has levels of agreement similar to, if not better than, those associated with more complex grading systems.

  10. Hole transfer from single quantum dots.

    PubMed

    Song, Nianhui; Zhu, Haiming; Jin, Shengye; Lian, Tianquan

    2011-11-22

    Photoinduced hole transfer dynamics from single CdSe/CdS(3ML)/CdZnS(2ML)/ZnS(2ML) core/multishell quantum dots (QDs) to phenothiazine (PTZ) molecules were studied by single QD fluorescence spectroscopy to investigate the static and dynamic heterogeneities of the hole transfer process as well as its effect on the blinking dynamics of QDs. Ensemble-averaged transient absorption and fluorescence decay measurements show that excitons in QDs dissociate by transferring the valence band hole to PTZ with a time constant of 50 ns for the 1:1 PTZ-QD complex, and the subsequent charge recombination process (i.e., electron transfer from the conduction band of the reduced QD to oxidized PTZ to regenerate the complex in the ground state) occurs mainly on the 100 to 1000 ns time scale. Single QD-PTZ complexes show pronounced correlated fluctuations of fluorescence intensity and lifetime with time. In addition to the dynamic fluctuation, there are considerable heterogeneities of average hole transfer rate among different QD-PTZ complexes. The hole transfer process has little effect on the statistics of the off-states, which is often believed to be positively charged QDs with a valence band hole. Instead, it increases the probability of weakly emissive or "gray" states.

  11. Transfer functions for a single flexible link

    SciTech Connect

    Wang, D. ); Vidyasagar, M. )

    1991-10-01

    This article examines some issues in the transfer function modeling of a single flexible link. Using the assumed-modes approach to represent the elastic deformation, one can find the transfer function between the torque input and the net tip deflection. It is shown here that when the number of modes is increased for more accurate modeling, the relative degree of the transfer function becomes ill defined. This can greatly affect the performance of a controller designed using this model. It is then shown that this problem occurs regardless of the method used to represent the elastic deformation. An alternate modeling approach is proposed that used the rigid body deformations minus the elastic deformations as the output. This solves this problem and results in a transfer function with a well-defined relative degree of two. Simulation results are presented that illustrate the advantages of using the proposed alternate transfer function.

  12. Vitrification: a simple and successful method for cryostorage of human blastocysts.

    PubMed

    Liebermann, Juergen

    2015-01-01

    Cryopreservation is one of the keystones in clinical infertility treatment. Especially vitrification has become a well-established and widely used routine procedure that allows important expansion of therapeutic strategies when in vitro fertilization (IVF) is used to treat infertility. Vitrification of human blastocysts allows us to maximize the potential for conception from any one in vitro fertilization cycle and prevents wastage of embryos. This goes even further toward to best utilize a patient's supernumerary oocytes after retrieval, maximizing the use of embryos from a single stimulation cycle. The technology may even be used to eliminate fresh embryo transfers for reasons of convenience, uterine receptivity, fertility preservation, preimplantation genetic diagnosis, or emergency management. In this chapter, the application of vitrification technology for cryopreserving human blastocyst will be revealed through step-by-step protocols. The results that are presented using the described protocols underscore the robustness of the vitrification technology for embryo cryopreservation.

  13. Utility of FT-IR imaging spectroscopy in estimating differences between the quality of bovine blastocysts

    NASA Astrophysics Data System (ADS)

    Wiecheć, A.; Opiela, J.; Lipiec, E.; Kwiatek, W. M.

    2013-10-01

    This study was conducted to verify whether the FT-IR spectroscopy and Focal Plane Array (FPA) imaging can be successfully applied to estimate the quality of bovine blastocysts (on the basis of the concentration of nucleic acids and amides). The FT-IR spectra of inner cell mass from blastocysts of three different culture systems were examined. The spectral changes between blastocysts were analyzed in DNA (spectral range of 1240-950 cm-1) and protein amides (1800-1400 cm-1). Blastocyst 1 (BL1-HA) was developed from the fertilized oocyte cultured with low concentration of hialuronian (HA), Blastocyst 2 and 3 were developed from the oocytes cultured in standard conditions. Cleavage stage blastocyst 2 (BL2-SOF) has been cultured in SOF medium while blastocyst 3 (BL3-VERO) was cultured in co-culture with VERO cells. The multivariate statistical analysis (Hierarchical Cluster Analysis - HCA and Principal Component Analysis - PCA) of single cells spectra showed high similarity of cells forming the inner cell mass within single blastocyst. The main variance between the three examined blastocysts was related to amides bands. Differences in the intensities of the amides' peaks between the bovine blastocysts derived from different culture systems indicated that specific proteins reflecting the appearance of a new phenotype were produced. However, for the three blastocysts, the α-helix typical peak was twice more intensive than the β-sheet typical peak suggesting that the differentiation processes had been started. Taking into account the quantitative and qualitative composition of the protein into examined blastocysts, it can be assumed, that the quality of the BL1-HA turned out much more similar to BL3-VERO than to BL2-SOF. FT-IR spectroscopy can be successfully applied in reproductive biology research for quality estimation of oocytes and embryos at varied stages of their development. Moreover this technique proved to be particularly useful when the quantity of the

  14. Deliveries from trophectoderm biopsied, fresh and vitrified blastocysts derived from polar body biopsied, vitrified oocytes.

    PubMed

    Grifo, Jamie; Adler, Alexis; Lee, Hsiao Ling; Morin, Scott J; Smith, Meghan; Lu, Lucy; Hodes-Wertz, Brooke; McCaffrey, Caroline; Berkeley, Alan; Munné, Santiago

    2015-08-01

    This longitudinal study reports preliminary findings of six patients who underwent first polar body biopsy followed by oocyte vitrification. All oocytes were warmed, inseminated by intracytoplasmic sperm injection and cultured to blastocyst. All suitable blastocysts underwent trophectoderm biopsy for aneuploidy screening, and supernumerary blastocysts were vitrified. Euploid blastocysts were transferred either fresh or in a subsequent programmed cycle. Of the 91 metaphase II oocytes, 30 had euploid first polar bodies. Development to blastocyst was more likely in oocytes with a euploid first polar body (66.7% versus 24.6%; P < 0.001). Nineteen euploid blastocysts were produced: 10 from oocytes with a euploid first polar body and nine from oocytes with an aneuploid first polar body. Five out of six patients (83%) had a live birth or ongoing pregnancy at the time of analysis. Eleven euploid blastocysts have been transferred and seven implanted (64%). Although the chromosomal status of the first polar body was poorly predictive of embryonic ploidy, an association was found between chromosomal status of the first polar body and development to blastocyst. Further study is required to characterize these relationships, but proof of concept is provided that twice biopsied, twice cryopreserved oocytes and embryos can lead to viable pregnancies.

  15. The effects of fertilization mode, embryo morphology at day 3, and female age on blastocyst formation and the clinical outcomes.

    PubMed

    Yin, Huiqun; Jiang, Hong; He, Ruibing; Wang, Cunli; Zhu, Jie; Luan, Kang

    2015-01-01

    The aim of this study was to evaluate the influence of in vitro fertilization (IVF) versus intracytoplasmic sperm injection (ICSI), fertilization mode embryonic morphology at day 3, and female age on blastocyst development, on the clinical outcomes of pregnancy after blastocyst transfer. A total of 471 cycles were retrospectively investigated. The rates of blastocyst formation and of good blastocyst morphology were higher in IVF than in ICSI cycles but there were no significant differences in the clinical pregnancies or in the miscarriage rates. The rates of formation of blastocyst and of blastocysts with good morphology were significantly higher from good-morphology embryos than from poor-morphology embryos. Nevertheless, 16.9% of the poor-morphology embryos reached the blastocyst stage. The total rates of blastocyst formation, and rates of clinical pregnancy and implantation were statistically similar in the age <35, 35-39, and >39 year groups, although tending to decrease with increasing age. When equal numbers of embryos were transferred on day 3, the rates of clinical pregnancy and implantation after blastocyst transfer were significantly higher in the <35 year age group than in the 35-39 and >39 year age groups, which were not significantly different. The miscarriage rates after embryo or blastocyst transfers were not statistically different in groups of similar age. Therefore, extended embryo culture up to the blastocyst stage could be implemented for women aged younger than 35 years to increase the pregnancy rate. For older women, transfer and vitrification of available embryos at day 3 and extended culture of morphologically poor embryos to the blastocyst stage for cryopreservation may improve the clinical outcome.

  16. Making the Mouse Blastocyst: Past, Present, and Future.

    PubMed

    Rossant, Janet

    2016-01-01

    The study of the preimplantation mouse embryo has progressed over the past 50 years from descriptive biology through experimental embryology to molecular biology and genetics. Along the way, the molecular pathways that lead to the establishment of the three cell lineages of the blastocyst have become more clearly understood but the fundamental questions of lineage commitment remain the same as those laid out in early studies. With new tools of genome manipulation, in vivo imaging and single-cell analysis, the mouse blastocyst is an excellent model system to understand how organized cell fate decisions are made in a self-organizing developmental context.

  17. Clinical outcomes after IVF or ICSI using human blastocysts derived from oocytes containing aggregates of smooth endoplasmic reticulum.

    PubMed

    Itoi, Fumiaki; Asano, Yukiko; Shimizu, Masashi; Nagai, Rika; Saitou, Kanako; Honnma, Hiroyuki; Murata, Yasutaka

    2017-01-25

    In this study the clinical and neo-natal outcomes after transfer of blastocysts derived from oocytes containing aggregates of smooth endoplasmic reticulum (SER) were compared between IVF and intracytoplasmic sperm injection (ICSI) cycles. Clinical and neo-natal outcomes of blastocysts in cycles with at least one SER metaphase II oocyte (SER + MII; SER + cycles) did not significantly differ between the two insemination methods. When SER + MII were cultured to day 5/6, fertilization, embryo cleavage and blastocyst rates were not significantly different between IVF and ICSI cycles. In vitrified-warmed blastocyst transfer cycles, the clinical pregnancy rates from SER + MII in IVF and ICSI did not significantly differ. In this study, 52 blastocysts (27 IVF and 25 ICSI) derived from SER + MII were transferred, yielding 15 newborns (5 IVF and 10 ICSI) and no malformations. Moreover, 300 blastocysts (175 IVF and 125 ICSI) derived from SER-MII were transferred, yielding 55 newborns (24 IVF and 31 ICSI cycles). Thus, blastocysts derived from SER + cycles exhibited an acceptable ongoing pregnancy rate after IVF (n = 125) or ICSI (n = 117) cycles. In conclusion, blastocysts from SER + MII in both IVF and ICSI cycles yield adequate ongoing pregnancy rates with neo-natal outcomes that do not differ from SER-MII.

  18. GPR30 Mediates the Fast Effect of Estrogen on Mouse Blastocyst and its Role in Implantation.

    PubMed

    Yu, Lin-lin; Qu, Ting; Zhang, Shi-mao; Yuan, Dong-zhi; Xu, Qian; Zhang, Jin-hu; He, Ya-ping; Yue, Li-min

    2015-10-01

    Our previous work demonstrated that estrogen could rapidly increase intracellular Ca(2+) in dormant mouse blastocysts. The purpose of the present study is to investigate the physiological relevance of G protein-coupled receptor 30 (GPR30) in the fast effect of estrogen on mouse blastocyst and in embryo implantation. We used reverse transcription-polymerase chain reaction, immunofluorescence, embryo coculture with Ishikawa uterine epithelial cell line, and embryo transfer technology to detect the expression of GPR30 in mouse embryos and the nongenomic effects of estrogen via GPR30 on blastocyst. We found that GPR30 is expressed in the mouse blastocyst, and its location is mostly consistent with the binding site of estrogen. Both estrogen and GPR30-specific agonist G-1 rapidly increase the intracellular Ca(2+) and phospholipase C activation in blastocyst cells, while GPR30-specific antagonist G-15 blocked this effect of estrogen. The pretreatment of G-15 on blastocysts lead to a lower attachment rate and implantation rate. Our data collectively suggested that GPR30 can mediate the fast effect of estrogen on blastocysts and play an important role in embryo implantation.

  19. Birth of piglets from in vitro-produced porcine blastocysts vitrified and warmed in a chemically defined medium.

    PubMed

    Mito, Tomomi; Yoshioka, Koji; Noguchi, Michiko; Yamashita, Shoko; Misumi, Koji; Hoshi, Tsubasa; Hoshi, Hiroyoshi

    2015-11-01

    We examined the effect of different embryo developmental stages, culture periods, and media on the cryotolerance of in vitro-produced porcine blastocysts. All media used for in vitro production, vitrification, and warming were chemically defined. When in vitro-produced embryos at the blastocyst and expanded blastocyst stages were vitrified using the Cryotop method on Day 5 or 6 (Day 0 = the day of IVF), the survival rate and hatching rate of expanded blastocysts after warming were higher than those of blastocysts. The viability after vitrification and warming of Day-6 embryos cultured in porcine blastocyst medium from Day 5 were higher than that of embryos cultured in porcine zygote medium 5. On the other hand, there were no significant differences on the cryotolerance between Day-5 embryos cultured in porcine zygote medium 5 and those replaced with porcine blastocyst medium on Day 4. There were no significant differences in viability between the embryonic ages of 5 and 6 days after vitrification and warming. When expanded blastocysts vitrified on Day 5 or 6 were surgically transferred to recipient gilts, all three recipients became pregnant in the Day-5 group, whereas only one out of three recipients became pregnant in the Day-6 group. These results indicate that the cryotolerance of porcine in vitro-produced blastocysts after vitrification appears to depend on the embryonic stage, culture period, and medium.

  20. Inadequacy of single-impulse transfers for path constrained rendezvous

    NASA Technical Reports Server (NTRS)

    Stern, S. A.; Soileau, K. M.

    1987-01-01

    The use of single-impulse techniques to maneuver from point to point about a large space structure (LSS) with an arbitrary geometrical configuration and spin is examined. Particular consideration is given to transfers with both endpoints on the forbidden zone surface. Clohessy-Wiltshire equations of relative motion are employed to solve path constrained rendezvous problems. External and internal transfers between arbitrary points are analyzed in terms of tangential departure and arrival conditions. It is observed that single-impulse techniques are inadequate for transferring about the exterior of any LSS; however, single-impulse transfers are applicable for transfers in the interior of LSSs. It is concluded that single-impulse transducers are not applicable for path constrained rendezvous guidance.

  1. Effect of the presence of trophectoderm vesicles on blastocyst in relation to in vitro hatching, clinical pregnancy, and miscarriage rates.

    PubMed

    Araki, Yasuhisa; Matsui, Yuki; Iizumi, Ayaka; Tsuchiya, Syoutarou; Kaneko, Yumi; Sato, Kazufumi; Ozaki, Tomoya; Araki, Yasuyuki; Nishimura, Mitsuru

    2016-10-01

    Trophectoderm vesicles (TVs) are observed in some blastocysts that penetrate cells from the zona pellucida to the outer margin. Therefore, we compared this incidence in relation to hatching, pregnancy, and miscarriage rates between conventional in vitro fertilization (c-IVF) and intracytoplasmic sperm injection (ICSI). Vitrified/warmed blastocysts (n = 112) were derived from surplus embryos. The blastocysts were then observed using time-lapse cinematography to resolve the relationship between hatching and implantation. Another study was conducted that comprised 681 embryo transfer cycles in 533 patients who received a single vitrified/warmed blastocyst from our clinic. The incidence of TV was significantly higher in embryos inseminated by ICSI compared with c-IVF [ICSI: 51/56 (91 %); c-IVF: 25/56 (45 %); P < 0.01]. The successful hatching rate was significantly lower in ICSI than in c-IVF [ICSI: 11/56 (20 %); c-IVF: 29/56 (52 %); P < 0.01]. In addition, the hatching rate was significantly lower when TVs were present (14/76; 18 %) than in non-TV embryos (26/36; 72 %) (P < 0.01). In regard to the clinical study results, no significant differences were found between the groups in the pregnancy rate (TV present group: 107/183, 58.5 %; TV absent group: 273/498, 54.8 %) and miscarriage rate (TV present group: 21/107, 19.6 %; TV absent group: 53/273, 19.4 %). In vivo, we hypothesized that hatching and hatched would occur naturally by assisting protease action in the uterus; therefore, these results suggest that the presence of TV has no effect on pregnancy rates in the clinical setting.

  2. Morphological and cytogenetic assessment of cleavage and blastocyst stage embryos.

    PubMed

    Fragouli, E; Alfarawati, S; Spath, K; Wells, D

    2014-02-01

    Morphological assessments are the main way in which fertility clinics select in vitro generated embryo(s) for transfer to the uterus. However, it is widely acknowledged that the microscopic appearance of an embryo is only weakly correlated with its viability. Furthermore, the extent to which morphology is affected by aneuploidy, a genetic defect common in human preimplantation embryos, remains unclear. Aneuploidy is of great relevance to embryo selection as it represents one of the most important causes of implantation failure and miscarriage. The current study aimed to examine whether morphological appearance can assist in identifying embryos at risk of aneuploidy. Additionally, the data produced sheds light on how chromosomal anomalies impact development from the cleavage to the blastocyst stage. A total of 1213 embryos were examined. Comprehensive chromosome analysis was combined with well-established criteria for the assessment of embryo morphology. At the cleavage stage, chromosome abnormalities were common even amongst embryos assigned the best morphological scores, indicating that aneuploidy has little effect on microscopic appearance at fixed time points up until Day 3 of development. However, at the blastocyst stage aneuploidies were found to be significantly less common among embryos of optimal morphological quality, while such abnormalities were overrepresented amongst embryos considered to be of poor morphology. Despite the link between aneuploidy and blastocyst appearance, many chromosomally abnormal embryos were able to achieve the highest morphological scores. In particular, blastocysts affected by forms of aneuploidy with the greatest capacity to produce clinical pregnancies (e.g. trisomy 21) were indistinguishable from euploid embryos. The sex ratio was seen to be equal throughout preimplantation development. Interestingly, however, females were overrepresented amongst the fastest growing cleavage-stage embryos, whereas a sex-related skew in the

  3. Successful production of piglets derived from expanded blastocysts vitrified using a micro volume air cooling method without direct exposure to liquid nitrogen.

    PubMed

    Misumi, Koji; Hirayama, Yuri; Egawa, Sachiko; Yamashita, Shoko; Hoshi, Hiroyoshi; Imai, Kei

    2013-12-17

    This study was conducted to clarify the feasibility of newly developed vitrification techniques for porcine embryos using the micro volume air cooling (MVAC) method without direct contact with liquid nitrogen (LN₂). Expanded blastocysts were vitrified in a solution containing 6 M ethylene glycol, 0.6 M trehalose and 2% (wt/vol) polyethylene glycol in 10% HEPES-buffered PZM-5. The blastocysts were collected from gilts and vitrified using the new device (MVAC) or a Cryotop (CT). Blastocysts were stored in LN₂ for at least 1 month. After warming, cryoprotective agents were removed using a single step. Survival of the embryos was assessed by in vitro culture (Experiment 1) and by embryo transfer to recipients (Experiment 2). In Experiment 1, the embryos vitrified by the MVAC or CT and fresh embryos without vitrification (Control) were used. The survival rates of embryos in the MVAC, CT and Control groups were 88.9% (32/36), 91.7% (33/36) and 100% (34/34), respectively, after 48 h culture, and the hatching rates of embryos after 48 h incubation were 69.4% (25/36), 63.9% (23/36) and 94.1% (32/34), respectively. In Experiment 2, 64 vitrified embryos were transferred to 5 recipient gilts, and 8 healthy piglets were produced from 3 recipients in the MVAC group. Similarly, 66 vitrified embryos were transferred to 5 recipient gilts, and 9 healthy piglets were produced from 2 recipients in the CT group. These results indicated that porcine expanded blastocysts can be cryopreserved using the MVAC method without potential pathogen contamination from LN₂.

  4. Successful Production of Piglets Derived from Expanded Blastocysts Vitrified Using a Micro Volume Air Cooling Method without Direct Exposure to Liquid Nitrogen

    PubMed Central

    MISUMI, Koji; HIRAYAMA, Yuri; EGAWA, Sachiko; YAMASHITA, Shoko; HOSHI, Hiroyoshi; IMAI, Kei

    2013-01-01

    Abstract This study was conducted to clarify the feasibility of newly developed vitrification techniques for porcine embryos using the micro volume air cooling (MVAC) method without direct contact with liquid nitrogen (LN2). Expanded blastocysts were vitrified in a solution containing 6 M ethylene glycol, 0.6 M trehalose and 2% (wt/vol) polyethylene glycol in 10% HEPES-buffered PZM-5. The blastocysts were collected from gilts and vitrified using the new device (MVAC) or a Cryotop (CT). Blastocysts were stored in LN2 for at least 1 month. After warming, cryoprotective agents were removed using a single step. Survival of the embryos was assessed by in vitro culture (Experiment 1) and by embryo transfer to recipients (Experiment 2). In Experiment 1, the embryos vitrified by the MVAC or CT and fresh embryos without vitrification (Control) were used. The survival rates of embryos in the MVAC, CT and Control groups were 88.9% (32/36), 91.7% (33/36) and 100% (34/34), respectively, after 48 h culture, and the hatching rates of embryos after 48 h incubation were 69.4% (25/36), 63.9% (23/36) and 94.1% (32/34), respectively. In Experiment 2, 64 vitrified embryos were transferred to 5 recipient gilts, and 8 healthy piglets were produced from 3 recipients in the MVAC group. Similarly, 66 vitrified embryos were transferred to 5 recipient gilts, and 9 healthy piglets were produced from 2 recipients in the CT group. These results indicated that porcine expanded blastocysts can be cryopreserved using the MVAC method without potential pathogen contamination from LN2. PMID:23955236

  5. Can repeated IVF-ICSI-cycles be avoided by using blastocysts developing from poor-quality cleavage stage embryos?

    PubMed

    Kaartinen, Noora; Das, Pia; Kananen, Kirsi; Huhtala, Heini; Tinkanen, Helena

    2015-03-01

    In many clinics, good-quality embryos are selected for embryo transfer and cryopreservation at the cleavage stage, and poor-quality embryos are discarded. The aim of this retrospective study was to examine how many repeated IVF cycles could be avoided by culturing the cleavage stage poor-quality embryos to blastocyst stage and transferring them after vitrification and warming (604 IVF and intracytoplasmic sperm injection [IVF-ICSI] cycles were included). Poor-quality cleavage stage embryos not eligible for transfer or cryopreservation were cultured until day 5 or 6, and those developing to the blastocyst stage were vitrified. The rate of vitrified blastocysts and clinical pregnancy and delivery rate of the warmed blastocysts was evaluated. The effect of the extended culture on the cumulative delivery rate, and the number of avoided new treatment cycles was calculated. The surplus blastocysts resulted in clinical pregnancy, spontaneous abortion and delivery rates of 24.6%, 27.3% and 17.2% respectively. The use of surplus blastocysts raised cumulative delivery rate from 43% to 47% and 53 repeated new cycles were avoided. This study shows that the cumulative delivery rate can be increased, and repeated IVF-ICSI treatments avoided by using blastocysts developing from poor-quality cleavage stage embryos, which otherwise would have been discarded.

  6. Prediction of porcine blastocyst formation using morphological, kinetic, and amino acid depletion and appearance criteria determined during the early cleavage of in vitro-produced embryos.

    PubMed

    Booth, Paul J; Watson, Terry J; Leese, Henry J

    2007-11-01

    .46-0.96, P = 0.028), and categorical values of blastomere number on Day 2 (all P < 0.02), although no single variate could accurately predict blastocyst formation. However, multivariate analysis of the cell numbers on Day 1 and Day 2 correctly classified 51.9% of the predicted blastocysts. The inclusion of cleavage time in the regression analysis raised this rate to 63.5%, which was increased to 66.2% by the addition of evenness of division and degree of fragmentation. Finally, the full logistic regression model, which incorporated amino acid score together with all the other morphologic and kinetic variables, correctly classified 80.8% of the predicted blastocysts. This represented 51.2% of the observed blastocysts. Our data are novel in that they not only define in a quantitative manner the influence of previously undescribed predictors of porcine blastocyst formation, but they also provide a simple model of preimplantation development with reasonable predictive accuracy. The present study also provides a basic model for the examination and incorporation of additional early morphologic and metabolic correlates of developmental competence and could potentially be applied to the selection of human embryos for transfer in clinical IVF.

  7. Survival and viability of vitrified in vitro and in vivo produced ovine blastocysts.

    PubMed

    Dattena, M; Ptak, G; Loi, P; Cappai, P

    2000-05-01

    Ovine blastocysts were produced by maturation, fertilization and in vitro culture (IVM/IVF/IVC) of oocytes from slaughtered adult and prepubertal ewes and collection from superovulated and inseminated adult animals. Dulbecco's PBS supplemented with 0.3 mM Na Pyruvate and 20% FCS was used as the basic cryopreservation solution. The embryos were exposed to the vitrification solution as follows: 10% glycerol (G) for 5 min, then 10% G +20% ethylene glycol (EG) for 5 min. Embryos were placed into 25% G + 25% EG in the center of 0.25- mL straws and plunged immediately into LN2. Warming was done by placing the straws into a water bath at 37 degrees C for 20 sec, and their contents were expelled into a 0.5 M sucrose solution for 3 min; the embryos were then transferred into 0.25 M and 0.125 M sucrose solution for 3 min each. Warmed blastocysts were transferred to the culture medium for 24 h. Survival was defined as the re-expansion of the blastocoele. All surviving blastocysts were transferred to synchronized recipient ewes, and the pregnancy was allowed to go to term. Of 68 vitrified in vitro produced blastocysts, 46 re-expanded (67.6%) and 10 lambs were born (14.7%). From the 62 in vivo derived and vitrified embryos, 52 re-expanded (83.8%) and 39 lambs were born (62.9%). The lambing rate of in vitro produced fresh transfer embryos was 40% (20 lambs/50 blastocysts transferred), and of the 32 in vivo derived blastocysts and transferred fresh, 26 lambs were born (81.2%). The results indicate that in vitro produced embryos can be successfully cryopreserved by vitrification.

  8. Intermittent Single-Molecule Interfacial Electron Transfer Dynamics

    SciTech Connect

    Biju, Vasudevan P.; Micic, Miodrag; Hu, Dehong; Lu, H. Peter

    2004-08-04

    We report on single molecule studies of photosensitized interfacial electron transfer (ET) processes in Coumarin 343 (C343)-TiO2 nanoparticle (NP) and Cresyl Violet (CV+)-TiO2 NP systems, using time-correlated single photon counting coupled with scanning confocal fluorescence microscopy. Fluorescence intensity trajectories of individual dye molecules adsorbed on a semiconductor NP surface showed fluorescence fluctuations and blinking, with time constrants distributed from sub-milliseconds to several seconds.

  9. Aqueous proton transfer across single-layer graphene

    PubMed Central

    Achtyl, Jennifer L.; Unocic, Raymond R.; Xu, Lijun; Cai, Yu; Raju, Muralikrishna; Zhang, Weiwei; Sacci, Robert L.; Vlassiouk, Ivan V.; Fulvio, Pasquale F.; Ganesh, Panchapakesan; Wesolowski, David J.; Dai, Sheng; van Duin, Adri C. T.; Neurock, Matthew; Geiger, Franz M.

    2015-01-01

    Proton transfer across single-layer graphene proceeds with large computed energy barriers and is therefore thought to be unfavourable at room temperature unless nanoscale holes or dopants are introduced, or a potential bias is applied. Here we subject single-layer graphene supported on fused silica to cycles of high and low pH, and show that protons transfer reversibly from the aqueous phase through the graphene to the other side where they undergo acid–base chemistry with the silica hydroxyl groups. After ruling out diffusion through macroscopic pinholes, the protons are found to transfer through rare, naturally occurring atomic defects. Computer simulations reveal low energy barriers of 0.61–0.75 eV for aqueous proton transfer across hydroxyl-terminated atomic defects that participate in a Grotthuss-type relay, while pyrylium-like ether terminations shut down proton exchange. Unfavourable energy barriers to helium and hydrogen transfer indicate the process is selective for aqueous protons. PMID:25781149

  10. Aqueous proton transfer across single-layer graphene

    SciTech Connect

    Achtyl, Jennifer L.; Unocic, Raymond R.; Xu, Lijun; Cai, Yu; Raju, Muralikrishna; Zhang, Weiwei; Sacci, Robert L.; Vlassiouk, Ivan V.; Fulvio, Pasquale F.; Ganesh, Panchapakesan; Wesolowski, David J.; Dai, Sheng; van Duin, Adri C. T.; Neurock, Matthew; Geiger, Franz M.

    2015-03-17

    Proton transfer across single-layer graphene proceeds with large computed energy barriers and is thought to be unfavourable at room temperature unless nanoscale holes or dopants are introduced, or a potential bias is applied. Here we subject single-layer graphene supported on fused ​silica to cycles of high and low pH, and show that protons transfer reversibly from the aqueous phase through the graphene to the other side where they undergo acid–base chemistry with the silica hydroxyl groups. After ruling out diffusion through macroscopic pinholes, the protons are found to transfer through rare, naturally occurring atomic defects. Computer simulations reveal low energy barriers of 0.61–0.75 eV for aqueous proton transfer across hydroxyl-terminated atomic defects that participate in a Grotthuss-type relay, while ​pyrylium-like ether terminations shut down proton exchange. In conclusion, unfavourable energy barriers to helium and ​hydrogen transfer indicate the process is selective for aqueous protons.

  11. Aqueous proton transfer across single-layer graphene

    DOE PAGES

    Achtyl, Jennifer L.; Unocic, Raymond R.; Xu, Lijun; ...

    2015-03-17

    Proton transfer across single-layer graphene proceeds with large computed energy barriers and is thought to be unfavourable at room temperature unless nanoscale holes or dopants are introduced, or a potential bias is applied. Here we subject single-layer graphene supported on fused ​silica to cycles of high and low pH, and show that protons transfer reversibly from the aqueous phase through the graphene to the other side where they undergo acid–base chemistry with the silica hydroxyl groups. After ruling out diffusion through macroscopic pinholes, the protons are found to transfer through rare, naturally occurring atomic defects. Computer simulations reveal low energymore » barriers of 0.61–0.75 eV for aqueous proton transfer across hydroxyl-terminated atomic defects that participate in a Grotthuss-type relay, while ​pyrylium-like ether terminations shut down proton exchange. In conclusion, unfavourable energy barriers to helium and ​hydrogen transfer indicate the process is selective for aqueous protons.« less

  12. Technique of Coronary Transfer for TGA with Single Coronary Artery

    PubMed Central

    Kim, Tae Ho; Jung, Jae Jun; Kim, Yong Han; Yang, Ji-Hyuk; Jun, Tae-Gook

    2014-01-01

    An eight-day-old neonate was diagnosed with dextro-transposition of the great arteries, atrial septal defect, patent ductus arteriosus, and a single sinus origin of the coronary arteries. The single coronary artery originated from the left sinus (sinus 2), had a proximal left circumflex arterial branch, and passed anteriorly to the right side of the aorta, further branching into the right coronary and left anterior descending arteries. We successfully performed an arterial switch operation and coronary transfer by tube graft reconstruction with autologous aortic tissue to treat the dextro-transposition of the great arteries and atrial septal defect with a single-sinus origin of the coronary arteries. PMID:25551074

  13. Dissipation-enabled efficient excitation transfer from a single photon to a single quantum emitter

    NASA Astrophysics Data System (ADS)

    Trautmann, N.; Alber, G.

    2016-05-01

    We propose a scheme for triggering a dissipation-dominated highly efficient excitation transfer from a single-photon wave packet to a single quantum emitter. This single-photon-induced optical pumping turns dominant dissipative processes, such as spontaneous photon emission by the emitter or cavity decay, into valuable tools for quantum information processing and quantum communication. It works for an arbitrarily shaped single-photon wave packet with sufficiently small bandwidth provided a matching condition is satisfied which balances the dissipative rates involved. Our scheme does not require additional laser pulses or quantum feedback and does not rely on high finesse optical resonators. In particular, it can be used to enhance significantly the coupling of a single photon to a single quantum emitter implanted in a one-dimensional waveguide or even in a free space scenario. We demonstrate the usefulness of our scheme for building a deterministic quantum memory and a deterministic frequency converter between photonic qubits of different wavelengths.

  14. Condensation heat transfer of steam on a single horizontal tube

    NASA Astrophysics Data System (ADS)

    Graber, K. A.

    1983-06-01

    An experimental apparatus was designed, constructed and instrumented in an effort to systematically and carefully study the condensation heat-transfer coefficient on a single, horizontal tube. A smooth, thick-walled copper tube of length 133.5 mm, with an outside diameter of 15.9 mm and an inside diameter of 12.7 mm was instrumented with six wall thermocouples. The temperature rise across the test section was measured accurately using quartz crystal thermometers. The inside heat-transfer coefficient was determined using the Sieder-Tate correlation with leading coefficient of 0.029. Initial steam side data were taken at atmospheric pressure to test the data acquisition/reduction computer programs.

  15. Single photon time transfer link model for GNSS satellites

    NASA Astrophysics Data System (ADS)

    Vacek, Michael; Michalek, Vojtech; Peca, Marek; Prochazka, Ivan; Blazej, Josef

    2015-05-01

    The importance of optical time transfer serving as a complement to traditional microwave links, has been attested for GNSSes and for scientific missions. Single photon time transfer (SPTT) is a process, allowing to compare (subtract) time readings of two distant clocks. Such a comparison may be then used to synchronize less accurate clock to a better reference, to perform clock characterization and calibration, to calculate mean time out of ensemble of several clocks, displaced in space. The single-photon time transfer is well established in field of space geodesy, being supported by passive retro-reflectors within space segment of five known GNSSes. A truly two-way, active terminals work aboard of Jason-2 (T2L2) - multiphoton operation, GNSS Beidou (Compass) - SPTT, and are going to be launched within recent ACES project (ELT) - SPTT, and GNSS GLONASS - multiphoton operation. However, there is still missing comprehensive theoretical model of two-way (using satellite receiver and retroreflector) SPTT link incorporating all crucial parameters of receiver (both ground and space segment receivers), transmitter, atmosphere effects on uplink and downlink path, influence of retroreflector. The input to calculation of SPTT link performance will be among others: link budget (distance, power, apertures, beam divergence, attenuation, scattering), propagating medium (atmosphere scintillation, beam wander, etc.), mutual Tx/Rx velocity, wavelength. The SPTT model will be evaluated without the properties of real components. These will be added in the further development. The ground-to-space SPTT link performance of typical scenarios are modeled. This work is a part of the ESA study "Comparison of optical time-transfer links."

  16. Genome-Wide DNA Methylation Patterns of Bovine Blastocysts Developed In Vivo from Embryos Completed Different Stages of Development In Vitro

    PubMed Central

    Salilew-Wondim, Dessie; Fournier, Eric; Hoelker, Michael; Saeed-Zidane, Mohammed; Tholen, Ernst; Looft, Christian; Neuhoff, Christiane; Besenfelder, Urban; Havlicek, Vita; Rings, Franca; Gagné, Dominic; Sirard, Marc-André; Robert, Claude; A. Shojaei Saadi, Habib; Gad, Ahmed; Schellander, Karl; Tesfaye, Dawit

    2015-01-01

    Early embryonic loss and altered gene expression in in vitro produced blastocysts are believed to be partly caused by aberrant DNA methylation. However, specific embryonic stage which is sensitive to in vitro culture conditions to alter the DNA methylation profile of the resulting blastocysts remained unclear. Therefore, the aim of this study was to investigate the stage specific effect of in vitro culture environment on the DNA methylation response of the resulting blastocysts. For this, embryos cultured in vitro until zygote (ZY), 4-cell (4C) or 16-cell (16C) were transferred to recipients and the blastocysts were recovery at day 7 of the estrous cycle. Another embryo group was cultured in vitro until blastocyst stage (IVP). Genome-wide DNA methylation profiles of ZY, 4C, 16C and IVP blastocyst groups were then determined with reference to blastocysts developed completely under in vivo condition (VO) using EmbryoGENE DNA Methylation Array. To assess the contribution of methylation changes on gene expression patterns, the DNA methylation data was superimposed to the transcriptome profile data. The degree of DNA methylation dysregulation in the promoter and/or gene body regions of the resulting blastocysts was correlated with successive stages of development the embryos advanced under in vitro culture before transfer to the in vivo condition. Genomic enrichment analysis revealed that in 4C and 16C blastocyst groups, hypermethylated loci were outpacing the hypomethylated ones in intronic, exonic, promoter and proximal promoter regions, whereas the reverse was observed in ZY blastocyst group. However, in the IVP group, as much hypermethylated as hypomethylated probes were detected in gene body and promoter regions. In addition, gene ontology analysis indicated that differentially methylated regions were found to affected several biological functions including ATP binding in the ZY group, programmed cell death in the 4C, glycolysis in 16C and genetic imprinting and

  17. Single phase channel flow forced convection heat transfer

    SciTech Connect

    Hartnett, J.P.

    1999-04-01

    A review of the current knowledge of single phase forced convection channel flow of liquids (Pr > 5) is presented. Two basic channel geometries are considered, the circular tube and the rectangular duct. Both laminar flow and turbulent flow are covered. The review begins with a brief overview of the heat transfer behavior of Newtonian fluids followed by a more detailed presentation of the behavior of purely viscous and viscoelastic Non-Newtonian fluids. Recent developments dealing with aqueous solutions of high molecular weight polymers and aqueous solutions of surfactants are discussed. The review concludes by citing a number of challenging research opportunities.

  18. Blastocyst-endometrium interaction: intertwining a cytokine network.

    PubMed

    Castro-Rendón, W A; Castro-Alvarez, J F; Guzmán-Martinez, C; Bueno-Sanchez, J C

    2006-11-01

    The successful implantation of the blastocyst depends on adequate interactions between the embryo and the uterus. The development of the embryo begins with the fertilized ovum, a single totipotent cell which undergoes mitosis and gives rise to a multicellular structure named blastocyst. At the same time, increasing concentrations of ovarian steroid hormones initiate a complex signaling cascade that stimulates the differentiation of endometrial stromal cells to decidual cells, preparing the uterus to lodge the embryo. Studies in humans and in other mammals have shown that cytokines and growth factors are produced by the pre-implantation embryo and cells of the reproductive tract; however, the interactions between these factors that converge for successful implantation are not well understood. This review focuses on the actions of interleukin-1, leukemia inhibitory factor, epidermal growth factor, heparin-binding epidermal growth factor, and vascular endothelial growth factor, and on the network of their interactions leading to early embryo development, peri-implantatory endometrial changes, embryo implantation and trophoblast differentiation. We also propose therapeutical approaches based on current knowledge on cytokine interactions.

  19. Morphokinetics of human blastocyst expansion in vitro.

    PubMed

    Huang, T T F; Chinn, K; Kosasa, T; Ahn, H J; Kessel, B

    2016-12-01

    Time-lapse imaging offers new tools to study dynamic processes of development such as blastocyst formation and expansion. This study quantitatively describes expansion in human blastocysts from donated oocytes. Measurements of hourly interval rate of changes in the blastocoel cross-sectional area revealed oscillatory pulses having 2-4 h periodicities. Two types of oscillations were distinguished. An E-Type ('expansion') had positive peak and positive or slightly negative trough interval rate of change values, and these characterized most of the expansion period. A C-type ('contraction') represented an infrequent but notable contraction of the blastocoel with loss of blastocoel fluid. These were reversible within 2-4 h in both groups and followed by further expansion. Therefore, oscillatory pulses are an intrinsic property of the trophectoderm. The zona seems to variably dampen the amplitude of these pulses. Expansion kinetics were compared between blastocysts with known positive (KID+) or negative (KID-) implantation outcomes. Regression analysis suggests that expansion may be relatively restricted in KID- embryos blastulating at relatively later times. These data extend observations in other mammalian systems and may provide information useful for clinical selection algorithms.

  20. Fabrication and single-electron-transfer operation of a triple-dot single-electron transistor

    SciTech Connect

    Jo, Mingyu Uchida, Takafumi; Tsurumaki-Fukuchi, Atsushi; Arita, Masashi; Takahashi, Yasuo; Fujiwara, Akira; Nishiguchi, Katsuhiko; Ono, Yukinori; Inokawa, Hiroshi

    2015-12-07

    A triple-dot single-electron transistor was fabricated on silicon-on-insulator wafer using pattern-dependent oxidation. A specially designed one-dimensional silicon wire having small constrictions at both ends was converted to a triple-dot single-electron transistor by means of pattern-dependent oxidation. The fabrication of the center dot involved quantum size effects and stress-induced band gap reduction, whereas that of the two side dots involved thickness modulation because of the complex edge structure of two-dimensional silicon. Single-electron turnstile operation was confirmed at 8 K when a 100-mV, 1-MHz square wave was applied. Monte Carlo simulations indicated that such a device with inhomogeneous tunnel and gate capacitances can exhibit single-electron transfer.

  1. Effects of slow freezing procedure on late blastocyst gene expression and survival rate in rabbit.

    PubMed

    Saenz-de-Juano, Maria Desemparats; Marco-Jiménez, Francisco; Peñaranda, David S; Joly, Thierry; Vicente, José S

    2012-10-01

    Studies of embryo cryopreservation efficiency have focused mainly on technical and embryo factors. To determine how a slow freezing process affects embryo and fetal development, we studied in vivo development ability after the freezing procedure by assessing blastocyst development at Day 6, implantation, and birth rates. A transcriptional microarray study was also performed to compare gene expression of 6-day-old rabbit embryos previously frozen and transferred into recipient rabbit females to their in vivo counterparts. Our goal was to study which alteration caused by the freezing procedure still remained in late blastocyst stage just at the time when the implantation process began. A microarray specifically designed to study rabbit gene expression profiling was used in this study. Lower implantation and birth rates were obtained in frozen embryos than in the control group (29.9% and 25.7% vs 88.5% and 70.8% for frozen and control embryos, respectively). Likewise, differences were also observed in gene expression profiles. Compared to 6-day-old in vivo-derived embryos, viable frozen embryos presented 70 differentially expressed genes, 24 upregulated and 46 downregulated. In conclusion, our findings showed that the slow freezing process affected late blastocyst development, implantation, and birth rates and that the gene expression alterations identified at late blastocyst stage could be useful in understanding the differences in developmental potential observed and the deficiencies that might hinder implantation and fetal development.

  2. Photoinduced Electron Transfer Process Visualized on Single Silver Nanoparticles.

    PubMed

    Lei, Gang; Gao, Peng Fei; Yang, Tong; Zhou, Jun; Zhang, Hong Zhi; Sun, Shan Shan; Gao, Ming Xuan; Huang, Cheng Zhi

    2017-02-28

    Understanding the photoinduced electron transfer (PET) mechanism is vital to improving the photoelectric conversion efficiency for solar energy materials and photosensitization systems. Herein, we visually demonstrate the PET process by real-time monitoring the photoinduced chemical transformation of p-aminothiophenol (p-ATP), an important SERS signal molecule, to 4,4'-dimercaptoazobenzene on single silver nanoparticles (AgNPs) with a localized surface plasmon resonance (LSPR) spectroscopy coupled dark-field microscopy. The bidirectional LSPR scattering spectral shifts bathochromically at first and hypsochromically then, which are caused by the electron transfer delay of p-ATP, disclose the PET path from p-ATP to O2 through AgNPs during the reaction, and enable us to digitalize the corresponding electron loss and gain on the surface of AgNP at different time periods. This visualized PET process could provide a simple and efficient approach to explore the nature of PET and help to interpret the SERS mechanism in terms of p-ATP.

  3. Rho-Associated Kinase Activity Is Required for Proper Morphogenesis of the Inner Cell Mass in the Mouse Blastocyst1

    PubMed Central

    Laeno, Arlene May A.; Tamashiro, Dana Ann A.; Alarcon, Vernadeth B.

    2013-01-01

    ABSTRACT The blastocyst consists of the outer layer of trophectoderm and pluripotent inner cell mass (ICM), the precursor of the placenta and fetus, respectively. During blastocyst expansion, the ICM adopts a compact, ovoidal shape, whose proper morphology is crucial for normal embryogenesis. Rho-associated kinase (ROCK), an effector of small GTPase RHO signaling, mediates the diverse cellular processes of morphogenesis, but its role in ICM morphogenesis is unclear. Here, we demonstrate that ROCK is required for cohesion of ICM cells and formation of segregated tissues called primitive endoderm (PrE) and epiblast (Epi) in the ICM of the mouse blastocyst. Blastocyst treatment with ROCK inhibitors Y-27632 and Fasudil caused widening or spreading of the ICM, and intermingling of PrE and Epi. Widening of ICM was independent of trophectoderm because isolated ICMs as well as colonies of mouse embryonic stem cells (mESC) also spread upon Y-27632 treatment. PrE, Epi, and trophectoderm cell numbers were similar between control and treated blastocysts, suggesting that ROCK inhibition affected ICM morphology but not lineage differentiation. Rock1 and Rock2 knockdown via RNA interference in mESC also induced spreading, supporting the conclusion that morphological defects caused by the pharmacological inhibitors were due to ROCK inactivation. When blastocysts were transferred into surrogates, implantation efficiencies were unaffected by ROCK inhibition, but treated blastocysts yielded greater fetal loss. These results show that proper ICM morphology is dependent on ROCK activity and is crucial for fetal development. Our studies have wider implication for improving efficiencies of human assisted reproductive technologies that diminish pregnancy loss and promote successful births. PMID:23946538

  4. Cleavage kinetics analysis of human embryos predicts development to blastocyst and implantation.

    PubMed

    Dal Canto, Mariabeatrice; Coticchio, Giovanni; Mignini Renzini, Mario; De Ponti, Elena; Novara, Paola Vittoria; Brambillasca, Fausta; Comi, Ruggero; Fadini, Rubens

    2012-11-01

    Cleavage kinetics of human embryos is indicative of ability to develop to blastocyst and implant. Recent advances in time-lapse microscopy have opened new and important research opportunities. In this study involving infertile couples requiring standard IVF/intracytoplasmic sperm injection treatment, zygotes were cultured by integrated embryo-culture time-lapse microscopy to analyse cleavage times from the 2- to the 8-cell stages in relation to the ability to develop to blastocyst, expand and implant. In comparison to embryos arresting after 8-cell stage, times of cleavage to 7- and 8-cell stages of embryos developing to blastocyst were shorter (56.5 ± 8.1 versus 58.8 ± 10.4h, P=0.03 and 61.0 ± 9.4 versus 65.2 ± 13.0 h, P=0.0008, respectively). In embryos developing to blastocyst, absence of blastocoele expansion on day 5 was associated with progressive cleavage delay. Implanting embryos developed to 8-cell stage in a shorter period compared with those unable to implant (54.9 ± 5.2 and 58.0 ± 7.2h, respectively, P=0.035). In conclusion, cleavage from 2- to 8-cell stage occurs progressively earlier in embryos with the ability to develop to blastocyst, expand and implant. Conventional observation times on days 2 and 3 are inappropriate for accurate embryo evaluation. The speed at which human embryos cleave is known to be suggestive of their ability to develop in vitro to the blastocyst stage and implant after transfer into the uterus. Recent advances in time-lapse microscopy, which allows acquisition of images every 15-20 min, have opened new and important research opportunities. In a retrospective study involving infertile couples requiring standard IVF or intracytoplasmic sperm injection treatment, fertilized oocytes were cultured by an integrated embryo-culture time-lapse microscopy system in order to perform an analysis of cleavage times from the 2- to the 8-cell stage in relation to the ability to develop to blastocyst, expand and implant. In comparison to

  5. Extended culture up to the blastocyst stage: a strategy to avoid multiple pregnancies in assisted reproductive technologies.

    PubMed

    Sepúlveda, Soledad J; Portella, Jimmy R; Noriega, Luis P; Escudero, Ernesto L; Noriega, Luis H

    2011-01-01

    The aim of this study was to review the experience and outcomes of assisted reproduction cycles with embryos grown up to day 5 of development, comparing different parameters according to the ages of the patients. We retrospectively studied 1,874 assisted reproduction cycles where embryo culture was extended up to the fifth or sixth day of development. All IVF and ICSI cycles were included, comparing, according to patient age, the following rates: blastocyst formation, pregnancy, implantation and abortion. As control, we analyzed cycles with donated oocytes from young donors (OD). The number of embryos reaching the blastocyst stage is similar in all groups of patients. Only the OD group was different in terms of blastocyst formation, pregnancy and implantation rates. Patients over 39 years of age had an abortion rate of 59.1 %, which is significantly higher than the other groups. Extended embryo culture up to the blastocyst stage can be implemented in programs of assisted reproduction in order to increase the pregnancy rate. The potential of blastocyst implantation is high, allowing us to transfer fewer embryos and reduce the probability of multiple pregnancies.

  6. Vitrification of human laser treated blastocysts within cut standard straws (CSS): novel aseptic packaging and reduced concentrations of cryoprotectants.

    PubMed

    Isachenko, Vladimir; Katkov, Igor I; Yakovenko, Sergey; Lulat, Ayub G-M I; Ulug, Murat; Arvas, Ayse; Isachenko, Evgenia

    2007-06-01

    Vitrification of laser treated human blastocysts using reduced concentrations of permeable cryoprotectants was carried out by submerging cut standard straws (CSS) into liquid nitrogen. The CSS were made by cutting a standard 0.25 ml straw at an angle of approximately 45 degrees . After laser assisted hatching, 6 day blastocysts (n=250) were loaded into droplets of approximately 0.75 microl in the CSS and were either plunged directly into liquid nitrogen or first encased in a standard 0.5 ml straw (aseptic technique) before being vitrified. Permeable cryoprotectants (ethylene glycol+Me(2)SO) at concentrations of 15% and 20% v:v were tested for their effect on post warming re-expansion and post transfer pregnancy rates. Our results indicate that the use of reduced concentrations of cryoprotectants and aseptic packaging of blastocysts did not have any statistically significant impact on the study outcomes.

  7. Induction of cytotoxicity and apoptosis in mouse blastocysts by silver nanoparticles.

    PubMed

    Li, Po-Wn; Kuo, Tai-Hung; Chang, Ji-Hao; Yeh, Jui-Ming; Chan, Wen-Hsiung

    2010-08-16

    Silver nanoparticles (nanoAg) are antibacterial materials widely used in various products and medical supplies. In this report, we examined the cytotoxic effects of nanoAg on mouse embryos at the blastocyst stage, subsequent embryonic attachment and outgrowth in vitro, and in vivo implantation by embryo transfer. Blastocysts treated with 50 microM nanoAg exhibited significantly increased apoptosis and a corresponding decrease in total cell number. Importantly, the implantation success rate of blastocysts pretreated with nanoAg was lower than that of their control counterparts. Moreover, in vitro treatment with 50 microM nanoAg was associated with increased resorption of post-implantation embryos and decreased fetal weight. Our results collectively indicate that in vitro exposure to nanoAg induces apoptosis and retards early post-implantation development after transfer to host mice. However, nanoAg-stimulated embryonic cytotoxicity appeared lower than that induced by the Ag+ ion. The results collectively show that nanoAg has the potential to induce embryo cytotoxicity. Further studies are required to establish effective protection strategies against the cytotoxic effects of these nanoparticles.

  8. Promotion of human early embryonic development and blastocyst outgrowth in vitro using autocrine/paracrine growth factors.

    PubMed

    Kawamura, Kazuhiro; Chen, Yuan; Shu, Yimin; Cheng, Yuan; Qiao, Jie; Behr, Barry; Pera, Renee A Reijo; Hsueh, Aaron J W

    2012-01-01

    Studies using animal models demonstrated the importance of autocrine/paracrine factors secreted by preimplantation embryos and reproductive tracts for embryonic development and implantation. Although in vitro fertilization-embryo transfer (IVF-ET) is an established procedure, there is no evidence that present culture conditions are optimal for human early embryonic development. In this study, key polypeptide ligands known to be important for early embryonic development in animal models were tested for their ability to improve human early embryo development and blastocyst outgrowth in vitro. We confirmed the expression of key ligand/receptor pairs in cleavage embryos derived from discarded human tri-pronuclear zygotes and in human endometrium. Combined treatment with key embryonic growth factors (brain-derived neurotrophic factor, colony-stimulating factor, epidermal growth factor, granulocyte macrophage colony-stimulating factor, insulin-like growth factor-1, glial cell-line derived neurotrophic factor, and artemin) in serum-free media promoted >2.5-fold the development of tri-pronuclear zygotes to blastocysts. For normally fertilized embryos, day 3 surplus embryos cultured individually with the key growth factors showed >3-fold increases in the development of 6-8 cell stage embryos to blastocysts and >7-fold increase in the proportion of high quality blastocysts based on Gardner's criteria. Growth factor treatment also led to a 2-fold promotion of blastocyst outgrowth in vitro when day 7 surplus hatching blastocysts were used. When failed-to-be-fertilized oocytes were used to perform somatic cell nuclear transfer (SCNT) using fibroblasts as donor karyoplasts, inclusion of growth factors increased the progression of reconstructed SCNT embryos to >4-cell stage embryos. Growth factor supplementation of serum-free cultures could promote optimal early embryonic development and implantation in IVF-ET and SCNT procedures. This approach is valuable for infertility

  9. Discordant Growth of Monozygotic Twins Starts at the Blastocyst Stage: A Case Study

    PubMed Central

    Noli, Laila; Capalbo, Antonio; Ogilvie, Caroline; Khalaf, Yacoub; Ilic, Dusko

    2015-01-01

    Summary Discordant growth is a common complication of monochorionic/diamniotic pregnancies; in approximately 50% of cases, the cause is unknown. The case presented here suggests that discordant growth of monozygotic twins could start during preimplantation development. Two inner cell masses (ICMs) within the same blastocyst may originate in uneven splitting of a single “parental” ICM, or the two ICMs may be formed independently de novo. We studied the transcriptomes of two morphologically distinct ICMs within a single blastocyst using high-resolution RNA sequencing. The data indicated that the two ICM were at different stages of development; one was in the earliest stages of lineage commitment, while the other had already differentiated into epiblast and primitive endoderm. IGF1-mediated signaling is likely to play a key role in ICM growth and to be the major driver behind these differences. PMID:26584541

  10. Global gene expression profiles reveal significant nuclear reprogramming by the blastocyst stage after cloning.

    PubMed

    Smith, Sadie L; Everts, Robin E; Tian, X Cindy; Du, Fuliang; Sung, Li-Ying; Rodriguez-Zas, Sandra L; Jeong, Byeong-Seon; Renard, Jean-Paul; Lewin, Harris A; Yang, Xiangzhong

    2005-12-06

    Nuclear transfer (NT) has potential applications in agriculture and biomedicine, but the technology is hindered by low efficiency. Global gene expression analysis of clones is important for the comprehensive study of nuclear reprogramming. Here, we compared global gene expression profiles of individual bovine NT blastocysts with their somatic donor cells and fertilized control embryos using cDNA microarray technology. The NT embryos' gene expression profiles were drastically different from those of their donor cells and closely resembled those of the naturally fertilized embryos. Our findings demonstrate that the NT embryos have undergone significant nuclear reprogramming by the blastocyst stage; however, problems may occur during redifferentiation for tissue genesis and organogenesis, and small reprogramming errors may be magnified downstream in development.

  11. Single-collision studies of energy transfer and chemical reaction

    SciTech Connect

    Valentini, J.J.

    1993-12-01

    The research focus in this group is state-to-state dynamics of reaction and energy transfer in collisions of free radicals such as H, OH, and CH{sub 3} with H{sub 2}, alkanes, alcohols and other hydrogen-containing molecules. The motivation for the work is the desire to provide a detailed understanding of the chemical dynamics of prototype reactions that are important in the production and utilization of energy sources, most importantly in combustion. The work is primarily experimental, but with an important and growing theoretical/computational component. The focus of this research program is now on reactions in which at least one of the reactants and one of the products is polyatomic. The objective is to determine how the high dimensionality of the reactants and products differentiates such reactions from atom + diatom reactions of the same kinematics and energetics. The experiments use highly time-resolved laser spectroscopic methods to prepare reactant states and analyze the states of the products on a single-collision time scale. The primary spectroscopic tool for product state analysis is coherent anti-Stokes Raman scattering (CARS) spectroscopy. CARS is used because of its generality and because the extraction of quantum state populations from CARS spectra is straightforward. The combination of the generality and easy analysis of CARS makes possible absolute cross section measurements (both state-to-state and total), a particularly valuable capability for characterizing reactive and inelastic collisions. Reactant free radicals are produced by laser photolysis of appropriate precursors. For reactant vibrational excitation stimulated Raman techniques are being developed and implemented.

  12. Single-molecule interfacial electron transfer dynamics manipulated by an external electric current.

    PubMed

    Zhang, Guofeng; Xiao, Liantuan; Chen, Ruiyun; Gao, Yan; Wang, Xiaobo; Jia, Suotang

    2011-08-14

    Interfacial electron transfer (IET) dynamics in a 1,1'-dioctadecyl-3,3,3',3'-tetramethylindodicarbocyanine (DiD) dye molecule/indium tin oxide (ITO) film system have been probed at the ensemble and single-molecule levels. By comparing the difference in the external electric current (EEC) dependence of the fluorescence intensities and lifetimes of the ensembles and single molecules, it is shown that the single-molecule probe can effectively demonstrate IET dynamics. The backward electron transfer and electron transfer from the ground state induce single-molecule fluorescence quenching when an EEC is applied to the DiD/ITO film system.

  13. Condensation Heat Transfer of Steam on a Single Horizontal Tube.

    DTIC Science & Technology

    1983-06-01

    thermometers. The inside heat-transfer coefficient was determined using the Sieder - Tate correlation with leading coefficient of 0.029. Initial...measured accurately using quartz crystal thermometers. The inside heat-transfer coefficient was determined using the Sieder -Tate correlation with...ACQUISITION/REDUCTION 34 A. DATA ACQUISITION AND STORAGE 34 3. DATA REDUCTION 34 C. STEPWISE SOLUTION PROCEDURE 35 1 . Program SIEDER 35

  14. Role of prostaglandins in development of porcine blastocysts.

    PubMed

    Geisert, R D; Rasby, R J; Minton, J E; Wetteman, R P

    1986-02-01

    Rapid elongation of porcine blastocysts between Days 11 to 12 of pregnancy coincides with an increase in uterine luminal content of prostaglandins. The present study evaluated the effect of two prostaglandin synthesis inhibitors (indomethacin and flunixin meglumine) on elongation of porcine blastocysts from spherical to filamentous forms between Day 11 to 12 of pregnancy. Gilts were hemi-hysterectomized on Day 11 of pregnancy. The excised uterine horn was flushed with 0.9% saline and diameter of blastocysts recovered were measured. Immediately following surgery, pregnant gilts were assigned to receive either: 1) vehicle every 4 h, 2) flunixin meglumine (banamine) every 4 h, or 3) indomethacin every 12 h. The remaining uterine horn was removed and flushed after the time of blastocyst elongation estimated for each gilt on basis of blastocyst development in the first horn. Uterine flushings were analyzed for total calcium, protein, acid phosphatase activity, estrone, estradiol-17 beta and prostaglandin F. Pretreatment blastocyst diameter was similar for all groups and ranged from 1 mm to 20 mm. Treatment of gilts with either banamine or indomethacin effectively inhibited (P less than 0.001) the increase in uterine luminal content of PGF. Total calcium, estrone and estradiol-17 beta were not influenced by treatment. Total uterine luminal protein and acid phosphatase activity were reduced (P less than 0.05) in banamine treated gilts compared to those receiving vehicle or indomethacin treatments. Although total PGF recovered in uterine flushings was reduced during the period of blastocyst elongation, treatment with PGF synthetase inhibitors failed to block rapid elongation of blastocysts from the spherical to filamentous forms.

  15. Altered gene expression profiles in mouse tetraploid blastocysts.

    PubMed

    Park, Mi-Ryung; Hwang, Kyu-Chan; Bui, Hong-Thuy; Cho, Ssang-Goo; Park, Chankyu; Song, Hyuk; Oh, Jae-Wook; Kim, Jin-Hoi

    2012-01-01

    In this study, it was demonstrated that tetraploid-derived blastocyst embryos had very few Oct4-positive cells at the mid-blastocyst stage and that the inner cell mass at biomarkers Oct4, Sox2 and Klf4 was expressed at less than 10% of the level observed in diploid blastocysts. In contrast, trophectoderm-related gene transcripts showed an approximately 10 to 40% increase. Of 32,996 individual mouse genes evaluated by microarray, 50 genes were differentially expressed between tetraploid or diploid and parthenote embryos at the blastocyst stage (P<0.05). Of these 50 genes, 28 were more highly expressed in tetraploid-derived blastocysts, whereas 22 were more highly downregulated. However, some genes involved in receptor activity, cell adhesion molecule, calcium ion binding, protein biosynthesis, redox processes, transport, and transcription showed a significant decrease or increase in gene expression in the tetraploid-derived blastocyst embryos. Thus, microarray analysis can be used as a tool to screen for underlying defects responsible for the development of tetraploid-derived embryos.

  16. Possible role of prostaglandin F in blastocyst implantation

    SciTech Connect

    Kasamo, M.; Ishikawa, M.; Yamashita, K.; Sengoku, K.; Shimizu, T.

    1986-02-01

    The synthesis and release of Prostaglandin F (PGF) by the rabbit blastocyst and endometrium were investigated on Day 6 and Day 7, using radioimmunoassay, autoradiography and conversion experiments. The following results were obtained: The content of PGF in the blastocyst increased significantly (P less than 0.01) from Day 6 to Day 7. The content of PGF in the endometrium was significantly higher (P less than 0.05) on Day 7 implantation sites compared to the other areas. The in vitro synthesis and release of PGF by Day 6 blastocysts sharply increased after one and two hours of culture, respectively. Thereafter both values declined with time. The in vitro synthesis and release of PGF by Day 6 endometria increased continuously with time. /sup 14/C-arachidonic acid (/sup 14/C-AA) was incorporated into Day 6 blastocysts in vitro and converted to PGF2 alpha. These results suggest that both the endometrium and the blastocyst are the sources of the PGs involved in implantation, and that PGF derived from the blastocysts may act as the trigger of implantation.

  17. Rabbit blastocysts accumulate [3H]prostaglandins in vitro.

    PubMed

    Jones, M A; Harper, M J

    1984-08-01

    Rabbit blastocysts obtained on days 5, 6, and 6.8 of pregnancy were incubated in vitro in Tyrode's buffer with 3H-labeled prostaglandins (PGs). Accumulation of PGs was studied, using Whatman GF/F filters to separate bound and free ligands. The uptake and efflux of [3H]PGs were studied as a function of PG type, incubation time, temperature, and effect of metabolic inhibitors as well as age and number of blastocysts. Blastocysts of the same age accumulated approximately the same amount of [3H]PGE2 and [3H]PGF2 alpha from their environment; however, there was no apparent saturation over a PG concentration range of 1-1000 nM. Both the uptake and efflux of PG were age dependent, with older blastocysts accumulating more PGs. Approximately 90% of the [3H]PGs appear to be transported into the blastocoelic fluid, with little PG remaining in the blastomeres. PG accumulation was relatively insensitive to azide, ouabain, cyanide, or bromcresol green, but was affected by incubation at 0 C or the addition of indomethacin (10 micrograms/ml). No catabolism of the accumulated PGs was observed. The release of PGE2 in general did not differ from that of PGF2 alpha, except on day 6.8 of pregnancy when PGE2 was released more rapidly than on day 6. We conclude that rabbit blastocysts can accumulate PGs from their environment, which may imply a storage potential in the blastocyst and release before implantation.

  18. Pair and single neutron transfer with Borromean 8He

    NASA Astrophysics Data System (ADS)

    Lemasson, A.; Navin, A.; Rejmund, M.; Keeley, N.; Zelevinsky, V.; Bhattacharyya, S.; Shrivastava, A.; Bazin, D.; Beaumel, D.; Blumenfeld, Y.; Chatterjee, A.; Gupta, D.; de France, G.; Jacquot, B.; Labiche, M.; Lemmon, R.; Nanal, V.; Nyberg, J.; Pillay, R. G.; Raabe, R.; Ramachandran, K.; Scarpaci, J. A.; Schmitt, C.; Simenel, C.; Stefan, I.; Timis, C. N.

    2011-03-01

    Direct observation of the survival of 199Au residues after 2n transfer in the 8He +197Au system and the absence of the corresponding 67Cu in the 8He +65Cu system at various energies are reported. The measurements of the surprisingly large cross sections for 199Au, coupled with the integral cross sections for the various Au residues, is used to obtain the first model-independent lower limits on the ratio of 2n to 1n transfer cross sections from 8He to a heavy target. A comparison of the transfer cross sections for 6,8He on these targets highlights the differences in the interactions of these Borromean nuclei. These measurements for the most neutron-rich nuclei on different targets highlight the need to probe the reaction mechanism with various targets and represent an experimental advance towards understanding specific features of pairing in the dynamics of dilute nuclear systems.

  19. Switching of the fluorescence emission of single molecules between the locally excited and charge transfer states

    NASA Astrophysics Data System (ADS)

    Angeles Izquierdo, M.; Bell, Toby D. M.; Habuchi, Satoshi; Fron, Eduard; Pilot, Roberto; Vosch, Tom; De Feyter, Steven; Verhoeven, Jan; Jacob, Josemon; Müllen, Klaus; Hofkens, Johan; De Schryver, Frans C.

    2005-01-01

    A novel perylene imide and oligo-pentaphenyl bisfluorene containing molecule is shown to undergo electron transfer to form an emissive charge transfer state in di-benzyl ether and THF. At the single molecule level in a PMMA film, fluorescence spectra characteristic of both emissive states (locally excited and charge transfer) are observed with 44% of the molecules studied showing switching between the two states. These results demonstrate that charge transfer fluorescence from single molecules can be used to report on the properties and dynamics of a molecule's immediate surroundings or nano-environment.

  20. Karyomapping identifies second polar body DNA persisting to the blastocyst stage: implications for embryo biopsy.

    PubMed

    Ottolini, Christian S; Rogers, Shaun; Sage, Karen; Summers, Michael C; Capalbo, Antonio; Griffin, Darren K; Sarasa, Jonas; Wells, Dagan; Handyside, Alan H

    2015-12-01

    Blastocyst biopsy is now widely used for both preimplantation genetic screening (PGS) and preimplantation genetic diagnosis (PGD). Although this approach yields good results, variable embryo quality and rates of development remain a challenge. Here, a case is reported in which a blastocyst was biopsied for PGS by array comparative genomic hybridization on day 6 after insemination, having hatched completely. In addition to a small trophectoderm sample, excluded cell fragments from the subzonal space from this embryo were also sampled. Unexpectedly, the array comparative genomic hybridization results from the fragments and trophectoderm sample were non-concordant: 47,XX,+19 and 46,XY, respectively. DNA fingerprinting by short tandem repeat and amelogenin analysis confirmed the sex chromosome difference but seemed to show that the two samples were related but non-identical. Genome-wide single nucleotide polymorphism genotyping and karyomapping identified that the origin of the DNA amplified from the fragments was that of the second polar body corresponding to the oocyte from which the biopsied embryo developed. The fact that polar body DNA can persist to the blastocyst stage provides evidence that excluded cell fragments should not be used for diagnostic purposes and should be avoided when performing embryo biopsies as there is a risk of diagnostic errors.

  1. Effect of the afterloaded external guidance embryo transfer technique on pregnancy rates in single embryo transfer cycles

    PubMed Central

    Yılmaz, Nafiye; Oruç, Ayla Sargın; Zeyrek, Tugba; Görkem, Ümit; İnal, Hasan Ali; Engin-Üstün, Yaprak; Gülerman, Cavidan

    2013-01-01

    Objective To investigate effect of the afterloaded external guidance embryo transfer technique on pregnancy rates in single embryo transfer intracytoplasmic sperm injection (ICSI) cycles. Material and Methods This retrospective study was performed at the Dr. Zekai Tahir Burak Women’s Health Research and Education Hospital. Three hundred and thirteen women who underwent ICSI were included in the study. Subjects were categorized according to the embryo transfer technique; Group 1 (n: 232): easy transfer with a soft catheter, Group 2 (n: 45): after external guidance transfer, and Group 3 (n: 36): difficult transfer with a stylet. Basal parameters, clinical and laboratory IVF outcomes and pregnancy rates were studied. Results Infertility etiology, basal follicle stimulating hormone (FSH) levels, antral follicle count, duration of stimulation, total dose of gonadotropin, peak estradiol levels, endometrial thickness, oocyte number, 2 PN, and fertilization rate were similar between the three groups (p>0.05). Despite the decreased pregnancy rate in Group 3, there were no differences in clinical pregnancy rates among the groups (p=0.204). Conclusion Embryo transfer is one of the critical steps in assisted reproduction procedures. Using the afterloaded external guidance embryo transfer technique did not improve pregnancy rates. PMID:24592095

  2. High bovine blastocyst development in a static in vitro production system using SOFaa medium supplemented with sodium citrate and myo-inositol with or without serum-proteins.

    PubMed

    Holm, P; Booth, P J; Schmidt, M H; Greve, T; Callesen, H

    1999-09-01

    We describe a bovine embryo culture system that supports repeatable high development in the presence of serum or BSA as well as under defined conditions in the absence of those components. In the first experiment, embryo development in SOF with amino acids (SOFaa), sodium citrate (SOFaac) and myo-inositol (SOFaaci) and with BSA or polyvinyl alcohol (PVA) was compared with that in a M199 granulosa cell co-culture (M199 co-culture). Subsequently, development and cell numbers of blastocysts cultured under defined conditions in SOFaaci with PVA (SOFaaci-PVA), or under undefined conditions in SOFaaci with 5% cow serum (SOFaaci-CS) or M199 co-culture were compared. The repeatability of culture results in SOFaaci-CS was checked by weekly replicates (n = 30) spread over 11 months. The viability of embryos developed in SOFaaci-PVA was estimated by transfer of morphologically good blastocysts (n = 10) to synchronized recipients. In the second experiment, the effect of omitting CS or BSA from IVM and IVM-IVF on subsequent embryo development in SOFaaci-PVA or in SOFaaci-CS was investigated. Blastocyst development in SOFaa-PVA, SOFaac-PVA, SOFaa-BSA and M199 was 16 +/- 3b, 23 +/- 2ab, 30 +/- 8a and 36 +/- 7a%, respectively (Pab < 0.05). Additional inclusion of myoinositol resulted in 42 +/- 1a% blastocysts in SOFaaci-PVA vs 19 +/- 3b% in SOFaac-PVA, 47 +/- 7a% in SOFaac-BSA, and 36 +/- 7a% in M199 co-culture, respectively (Pab < 0.01). In 30 replicates, the average cleavage and blastocyst rates of oocytes in SOFaaci-CS were 87 +/- 4 and 49 +/- 5%, respectively. Five normal calves were produced after transfer of 10 blastocysts developed in defined culture medium (i.e., SOFaaci-PVA). Defined IVM or IVM-IVF (i.e., in absence of CS and BSA) reduced cleavage rates (83 +/- 3 and 55 +/- 3% vs 90 +/- 1% in presence of CS; P < 0.01). Subsequent embryo development in SOFaaci-CS was not affected in either of these defined conditions. However, cleavage and blastocyst rates under completely

  3. Rat Blastocysts from Nuclear Injection and Time-Lagged Enucleation and Their Commitment to Embryonic Stem Cells.

    PubMed

    Hara, Hiromasa; Goto, Teppei; Takizawa, Akiko; Sanbo, Makoto; Jacob, Howard J; Kobayashi, Toshihiro; Nakauchi, Hiromitsu; Hochi, Shinichi; Hirabayashi, Masumi

    2016-04-01

    Pronucleus-like vesicle formation following premature chromosome condensation (PCC) of the donor cell nucleus is the key event for successful generation of cloned rodents by nuclear transplantation (NT). However in rat cloning, this change is difficult to induce in enucleated recipient oocytes because of their inability to maintain maturation-promoting factor levels. In this study, intact oocytes retrieved from nuclear-visualized H2B-tdTomato knock-in rats were injected with Venus-labeled cell nuclei. Because the incidence of PCC under MG-132 treatment significantly increased with the culture period (0%, 10.8%, 36.8%, and 87.5% at 0, 0.5, 1, and 2 h postinjection, respectively), the metaphase plate of the oocyte was removed 1-2 h after the nuclear injection. The NT-derived rat zygotes (n = 748) were activated with ionomycin/cycloheximide and transferred into temporal host mothers, resulting in the harvest of three blastocysts (0.4%) with Venus fluorescence. Two blastocysts were examined for their potential to commit to NT-derived embryonic stem cells (ntESCs). One ntESC line was established successfully and found to be competent in terms of karyotype, stem cell marker expression, and pluripotency. In conclusion, time-lagged enucleation of visualized oocyte nuclei allows the PCC incidence of donor nuclei and generation of NT blastocysts, and the blastocysts can commit to germline-competent ntESCs.

  4. Single-phase liquid jet impingement heat transfer

    SciTech Connect

    Webb, B.W.; Ma, C.F.

    1995-12-31

    Impinging liquid jets have been demonstrated to be an effective means of providing high heat/mass transfer rates in industrial transport processes. When a liquid jet strikes a surface, thin hydrodynamic and thermal boundary layers from in the region directly beneath due to the jet deceleration and the resulting increase in pressure. The flow is then forced to accelerate in a direction parallel to the target surface in what is termed the wall jet or parallel flow zone. The thickness of the hydrodynamic and thermal boundary layers in the stagnation region may be of the order of tens of micrometers. Consequently, very high heat/mass transfer coefficients exist in the stagnation zone directly under the jet. Transport coefficients characteristic of parallel flow prevail in the wall jet region. The high heat transfer coefficients make liquid jet impingement an attractive cooling option where high heat fluxes are the norm. Some industrial applications include the thermal treatment of metals, cooling of internal combustion engines, and more recently, thermal control of high-heat-dissipation electronic devices. Both circular and planar liquid jets have attracted research attention. 180 refs., 35 figs., 11 tabs.

  5. Technique to 'Map' Chromosomal Mosaicism at the Blastocyst Stage.

    PubMed

    Taylor, Tyl H; Griffin, Darren K; Katz, Seth L; Crain, Jack L; Johnson, Lauren; Gitlin, Susan

    2016-01-01

    The purpose of this study was to identify a technique that allows for comprehensive chromosome screening (CCS) of individual cells within human blastocysts along with the approximation of their location in the trophectoderm relative to the inner cell mass (ICM). This proof-of-concept study will allow for a greater understanding of chromosomal mosaicism at the blastocyst stage and the mechanisms by which mosaicism arises. One blastocyst was held by a holding pipette and the ICM was removed. While still being held, the blastocyst was further biopsied into quadrants. To separate the individual cells from the biopsied sections, the sections were placed in calcium/magnesium-free medium with serum for 20 min. A holding pipette was used to aspirate the sections until individual cells were isolated. Individual cells from each section were placed into PCR tubes and prepped for aCGH. A total of 18 cells were used for analysis, of which 15 (83.3%) amplified and provided a result and 3 (16.7%) did not. Fifteen cells were isolated from the trophectoderm; 13 (86.7%) provided an aCGH result, while 2 (13.3%) did not amplify. Twelve cells were euploid (46,XY), while 1 was complex abnormal (44,XY), presenting with monosomy 7, 10, 11, 13, and 19, and trisomy 14, 15, and 21. A total of 3 cells were isolated from the ICM; 2 were euploid (46,XY) and 1 did not amplify. Here, we expand on a previously published technique which disassociates biopsied sections of the blastocyst into individual cells. Since the blastocyst sections were biopsied in regard to the position of the ICM, it was possible to reconstruct a virtual image of the blastocyst while presenting each cell's individual CCS results.

  6. Ability of tetraploid rat blastocysts to support fetal development after complementation with embryonic stem cells.

    PubMed

    Hirabayashi, Masumi; Tamura, Chihiro; Sanbo, Makoto; Goto, Teppei; Kato-Itoh, Megumi; Kobayashi, Toshihiro; Nakauchi, Hiromitsu; Hochi, Shinichi

    2012-06-01

    This study was undertaken to generate rat offspring via tetraploid blastocyst complementation with embryonic stem (ES) cells. Tetraploid blastocysts were prepared by electrofusion of blastomeres from two-cell stage embryos, and subsequent in vivo culture for 4 days. Microinjection into the tetraploid blastocoel of an inner cell mass isolated by immunosurgery resulted in the generation of rat offspring, suggesting the successful contribution of tetraploid blastocysts to their placenta. Tetraploid blastocyst complementation was attempted with a total of 4 ES cell lines (2 lines of female karyotype and 2 lines of male karyotype). In the rESWIv-3i-5 (XX) cell line, normal-sized fetuses with heartbeats were harvested on E11.5 (12.1%), E12.5 (9.5%), and E13.5 (9.1%), but no viable fetuses were detected on E14.5. Similarly, use of the rESWIv-3i-1 (XX) cell line resulted in no viable fetus production on E14.5. Using the rESBLK2i-1 (XY) cell line, viable fetuses were harvested not only on E11.5-E13.5 (2.6-5.5%), but also on E14.5 (3.0%). The transfer of a total of 487 tetraploid blastocysts complemented with rESBLK2i-1 cells resulted in 256 implantation sites (52.6%) on E21.5, but no viable offspring was detected. Use of the rESBLK2i-1/huKO (XY) cell line also resulted in no viable offspring production on E21.5. Analyses of the methylation pattern in differentially methylated regions and transcript level of genes that are imprinted in mice (H19, Meg3, Igf2r, Peg5, and Peg10) in the E14.5 conceptuses indicated a marked difference between the ES cell-derived and control normal fetuses, but not between the tetraploid and control diploid placenta.

  7. Single crystalline BaTiO3 thin films synthesized using ion implantation induced layer transfer

    NASA Astrophysics Data System (ADS)

    Park, Young-Bae; Diest, Kenneth; Atwater, Harry A.

    2007-10-01

    Layer transfer of BaTiO3 thin films onto silicon-based substrates has been investigated. Hydrogen and helium ions were co-implanted to facilitate ion-implantation-induced layer transfer of films from BaTiO3 single crystals. From thermodynamic equilibrium calculations, we suggest that the dominant species during cavity nucleation and growth are H2, H+, H2O, Ba2+ and Ba-OH, and that the addition of hydrogen to the Ba-Ti-O system can effectively suppress volatile oxide formation during layer transfer and subsequent annealing. After ion implantation, BaTiO3 layers contain microstructural defects and hydrogen precipitates in the lattice, but after layer transfer, the single crystal is found to be stoichiometric. Using direct wafer bonding and layer splitting, single crystal BaTiO3 thin films were transferred onto amorphous Si3N4 and Pt substrates. Micro-Raman spectroscopy indicated that the density of defects generated by ion implantation in BaTiO3 can be significantly reduced during post-transfer annealing, returning the transferred layer to its single crystal state. Characterization using piezoresponse force microscopy shows that the layer transferred thin films are ferroelectric, with domain structures and piezoresponse characteristics similar to that of bulk crystals.

  8. The piggyBac-Based Gene Delivery System Can Confer Successful Production of Cloned Porcine Blastocysts with Multigene Constructs

    PubMed Central

    Sato, Masahiro; Maeda, Kosuke; Koriyama, Miyu; Inada, Emi; Saitoh, Issei; Miura, Hiromi; Ohtsuka, Masato; Nakamura, Shingo; Sakurai, Takayuki; Watanabe, Satoshi; Miyoshi, Kazuchika

    2016-01-01

    The introduction of multigene constructs into single cells is important for improving the performance of domestic animals, as well as understanding basic biological processes. In particular, multigene constructs allow the engineering and integration of multiple genes related to xenotransplantation into the porcine genome. The piggyBac (PB) transposon system allows multiple genes to be stably integrated into target genomes through a single transfection event. However, to our knowledge, no attempt to introduce multiple genes into a porcine genome has been made using this system. In this study, we simultaneously introduced seven transposons into a single porcine embryonic fibroblast (PEF). PEFs were transfected with seven transposons containing genes for five drug resistance proteins and two (red and green) fluorescent proteins, together with a PB transposase expression vector, pTrans (experimental group). The above seven transposons (without pTrans) were transfected concomitantly (control group). Selection of these transfected cells in the presence of multiple selection drugs resulted in the survival of several clones derived from the experimental group, but not from the control. PCR analysis demonstrated that approximately 90% (12/13 tested) of the surviving clones possessed all of the introduced transposons. Splinkerette PCR demonstrated that the transposons were inserted through the TTAA target sites of PB. Somatic cell nuclear transfer (SCNT) using a PEF clone with multigene constructs demonstrated successful production of cloned blastocysts expressing both red and green fluorescence. These results indicate the feasibility of this PB-mediated method for simultaneous transfer of multigene constructs into the porcine cell genome, which is useful for production of cloned transgenic pigs expressing multiple transgenes. PMID:27589724

  9. Ultrafast Single and Multiexciton Energy Transfer in Semiconductor Nanoplatelets

    NASA Astrophysics Data System (ADS)

    Schaller, Richard

    Photophysical processes such as fluorescence resonance energy transfer (FRET) enable optical antennas, wavelength down-conversion in light-emitting diodes (LEDs), and optical bio-sensing schemes. The rate and efficiency of this donor to acceptor transfer of excitation between chromophores dictates the utility of FRET and can unlock new device operation motifs including quantum-funnel solar cells and reduced gain thresholds. However, the fastest reported FRET time constants involving spherical quantum dots (QDs) (0.12-1 ns), do not outpace biexciton Auger recombination (0.01-0.1 ns), which impedes multiexciton-driven applications including electrically-pumped lasers and carrier-multiplication-enhanced photovoltaics. Precisely controlled, few-monolayer thick semiconductor nano-platelets with tens-of-nanometer diameters exhibit intense optical transitions and hundreds-of-picosecond Auger recombination, but heretofore lack FRET characterizations. We examine binary CdSe NPL solids and show that inter-plate FRET (~6-23 ps, presumably for co-facial arrangements) can occur 15-50 times faster than Auger recombination and demonstrate multiexcitonic FRET, making such materials ideal candidates for advanced technologies. This work was performed at the Center for Nanoscale Materials, a U.S. Department of Energy Office of Science User Facility under Contract No. DE-AC02-06CH11357.

  10. Chemical reaction fouling model for single-phase heat transfer

    SciTech Connect

    Panchal, C.B.; Watkinson, A.P.

    1993-08-01

    A fouling model was developed on the premise that the chemical reaction for generation of precursor can take place in the bulk fluid, in the thermalboundary layer, or at the fluid/wall interface, depending upon the interactive effects of flu id dynamics, heat and mass transfer, and the controlling chemical reaction. The analysis was used to examine the experimental data for fouling deposition of polyperoxides produced by autoxidation of indene in kerosene. The effects of fluid and wall temperatures for two flow geometries were analyzed. The results showed that the relative effects of physical parameters on the fouling rate would differ for the three fouling mechanisms; therefore, it is important to identify the controlling mechanism in applying the closed-flow-loop data to industrial conditions.

  11. Progesterone and its downstream molecules as blastocyst implantation essential factors.

    PubMed

    Yoshinaga, Koji

    2014-08-01

    This review is to update the previous review (Am J Reprod Immunol, 63, 2010 and 413) on the research on blastocyst implantation essential factors (BIEFs). Focus of the current review is on progesterone and its downstream molecules in the process of blastocyst implantation. To understand the process of implantation, we need to know where and when the BIEFs are expressed and what they do. Progress in this research area is rapid, and its update is indeed necessary. The basic concept of BIEFs is that they have dual functions, one physiological and the other immunological (J Reprod Dev, 58, 2012 and 196). As we are still exploring the mechanism of implantation, available data are incomplete and human data are few. Thus, I will use information obtained through research on animal models, in vitro studies, cell lines, and some human studies where available. The ultimate goal of the review is to understand human blastocyst implantation.

  12. In vitro embryo development and blastocyst hatching rates following vitrification of river buffalo embryos produced from oocytes recovered from slaughterhouse ovaries or live animals by ovum pick-up.

    PubMed

    Manjunatha, B M; Gupta, P S P; Ravindra, J P; Devaraj, M; Nandi, S

    2008-03-03

    The present study was undertaken to determine whether the source of oocytes (ovum pick up versus slaughterhouse ovaries) affected in vitro embryo production and embryo survival (as measured by blastocyst hatching rates) following vitrification in buffaloes (Bubalus bubalis). Oocytes recovered from live buffaloes (n=6) by ovum pick up (OPU) and by manual aspiration from slaughterhouse ovaries were in vitro matured, fertilized and cultured to blastocyst stage under same culture conditions. Vitrification of blastocysts was carried out in two steps at 24 degrees C. Embryos were equilibrated in 10% EG+10% DMSO+0.3 M sucrose in base medium for 4 min. Subsequently, the embryos were transferred into 25% EG+25% DMSO+0.3 M sucrose in base medium for 45 s and then the embryos were loaded into straws and immersed in liquid nitrogen. Following warming, blastocysts were cultured in vitro for 48 h to assess hatching. Oocytes derived from live animals by OPU resulted in a significantly higher blastocyst yield then those derived from slaughterhouse ovaries (30.6+/-4.3 versus 18.5+/-1.8). Blastocyst hatching rates following vitrification of buffalo embryos produced from the oocytes collected from live animals by OPU was significantly higher than the oocytes collected from slaughterhouse ovaries (52.8+/-4.2 versus 40.2+/-4.4). In conclusion, the present study showed that source of oocytes (OPU versus slaughterhouse ovaries) affects the in vitro embryo development and blastocyst hatching rates following vitrification of embryos in buffaloes.

  13. Amino acids promote human blastocyst development in vitro.

    PubMed

    Devreker, F; Hardy, K; Van den Bergh, M; Vannin, A S; Emiliani, S; Englert, Y

    2001-04-01

    Supplementation of culture media with amino acids has been shown to benefit preimplantation embryo development in several species. This randomized study analysed the in-vitro development of human embryos obtained after IVF in the presence or absence of a combination of amino acids from the 2- to 4-cell stage to the blastocyst stage. A total of 129 human embryos was randomly distributed between three serum-free chemically defined sequential media: (i) glucose-free Earle's balanced salt solution (EBSS) with glutamine (Gln) prior to morula stage, supplemented with glucose for blastocyst formation; (ii) glucose-free EBSS with glutamine and non-essential amino acids (AA) for cleavage stage development, and supplemented with all 20 AA for blastocyst formation (Earle's+AA); and (iii) a sequential commercial medium containing amino acids (K-SCIM). Embryos were individually cultured for successive periods of 24 h. On day 6 of development, blastocysts were differentially labelled and the numbers of trophectoderm and inner cell mass cells, mitoses and dead cells were examined. Blastocyst development was similar for the three sequential media. The mixture of AA significantly increased total blastocyst cell numbers from 61.8 +/- 4.2 with Earle's+Gln to 99.3 +/- 8.4 with Earle's+AA and 100.2 +/- 9.4 with K-SCIM (P = 0.005). This increase was present in both the trophectoderm and inner cell mass lineages (P < 0.02). Furthermore, the dead cell index was significantly lower with Earle's+AA (P = 0.047).

  14. Choline inhibition of amino acid transport in preimplantation mouse blastocysts

    SciTech Connect

    Campione, A.L.; Haghighat, N.; Gorman, J.; Van Winkle, L.J.

    1987-05-01

    Addition of 70 mM choline chloride to Brinster's medium (140 mM Na/sup +/) inhibited uptake of approx. 1 ..mu..M (/sup 3/H)glycine, leucine, lysine and alanine in blastocysts by about 50% each during a five-minute incubation period at 37/sup 0/C, whereas 70 mM LiCl, sodium acetate and NaCl or 140 mM mannitol had no effect. They attribute the apparent linear relationship between Gly transport in blastocysts and the square of the (Na/sup +/), observed when choline was substituted for Na/sup +/ in Brinster's medium, to concomitant, concentration-dependent enhancement and inhibition of transport by Na/sup +/ and choline, respectively. As expected, Gly uptake and the (Na/sup +/) were linearly related up to 116 mM Na/sup +/, when Na/sup +/ was replaced with Li/sup +/. The rates of Na/sup +/-independent Gly and Ala uptake were <5% and <2% of the total, respectively, and similar when either Li/sup +/ or choline replaced Na/sup +/. Therefore, neither Li/sup +/ nor choline appears to substitute for Na/sup +/ in supporting Na/sup +/-dependent transport in blastocysts. Na/sup +/-independent Leu uptake was 20 times faster than Gly or Ala uptake and appeared to be inhibited by choline in blastocysts since it was about 37% slower when choline instead of Li/sup +/ was substituted for Na/sup +/. In contrast to blastocysts, choline had no effect on amino acid transport in cleavage-stage mouse embryos. The unexpected sensitivity of transport to choline in blastocysts underscores the importance of testing the effects of this substance when it is used to replace Na/sup +/ in new transport studies.

  15. Rabbit blastocysts accumulate (/sup 3/H)prostaglandins in vitro

    SciTech Connect

    Jones, M.A.; Harper, M.J.

    1984-08-01

    Rabbit blastocysts obtained on days 5, 6, and 6.8 of pregnancy were incubated in vitro in Tyrode's buffer with /sup 3/H-labeled prostaglandins (PGs). Accumulation of PGs was studied, using Whatman GF/F filters to separate bound and free ligands. The uptake and efflux of (/sup 3/H)PGs were studied as a function of PG type, incubation time, temperature, and effect of metabolic inhibitors as well as age and number of blastocysts. Blastocysts of the same age accumulated approximately the same amount of (/sup 3/H)PGE2 and (/sup 3/H)PGF2 alpha from their environment; however, there was no apparent saturation over a PG concentration range of 1-1000 nM. Both the uptake and efflux of PG were age dependent, with older blastocysts accumulating more PGs. Approximately 90% of the (/sup 3/H)PGs appear to be transported into the blastocoelic fluid, with little PG remaining in the blastomeres. PG accumulation was relatively insensitive to azide, ouabain, cyanide, or bromcresol green, but was affected by incubation at 0 C or the addition of indomethacin (10 micrograms/ml). No catabolism of the accumulated PGs was observed. The release of PGE2 in general did not differ from that of PGF2 alpha, except on day 6.8 of pregnancy when PGE2 was released more rapidly than on day 6. The authors conclude that rabbit blastocysts can accumulate PGs from their environment, which may imply a storage potential in the blastocyst and release before implantation.

  16. Regulatory microRNA Network Identification in Bovine Blastocyst Development

    PubMed Central

    Mestdagh, Pieter; Lefever, Steve; Van Poucke, Mario; Van Zeveren, Alex; Van Soom, Ann; Vandesompele, Jo; Peelman, Luc

    2013-01-01

    Mammalian blastocyst formation is characterized by two lineage segregations resulting in the formation of the trophectoderm, the hypoblast, and the epiblast cell lineages. Cell fate determination during these early lineage segregations is associated with changes in the expression of specific transcription factors. In addition to the transcription factor-based control, it has become clear that also microRNAs (miRNAs) play an important role in the post-transcriptional regulation of pluripotency and differentiation. To elucidate the role of miRNAs in early lineage segregation, we compared the miRNA expression in early bovine blastocysts with the more advanced stage of hatched blastocysts. Reverse transcription–quantitative PCR-based miRNA expression profiling revealed eight upregulated miRNAs (miR-127, miR-130a, miR-155, miR-196a, miR-203, miR-28, miR-29c, and miR-376a) and four downregulated miRNAs (miR-135a, miR-218, miR-335, and miR-449b) in hatched blastocysts. Through an integrative analysis of matching miRNA and mRNA expression data, candidate miRNA-mRNA interaction pairs were prioritized for validation. Using an in vitro luciferase reporter assay, we confirmed a direct interaction between miR-218 and CDH2, miR-218 and NANOG, and miR-449b and NOTCH1. By interfering with the FGF signaling pathway, we found functional evidence that miR-218, mainly expressed in the inner cell mass, regulates the NANOG expression in the bovine blastocyst in response to FGF signaling. The results of this study expand our knowledge about the miRNA signature of the bovine blastocyst and of the interactions between miRNAs and cell fate regulating transcription factors. PMID:23398486

  17. Mechanically Controlled Electron Transfer in a Single-Polypeptide Transistor

    NASA Astrophysics Data System (ADS)

    Sheu, Sheh-Yi; Yang, Dah-Yen

    2017-01-01

    Proteins are of interest in nano-bio electronic devices due to their versatile structures, exquisite functionality and specificity. However, quantum transport measurements produce conflicting results due to technical limitations whereby it is difficult to precisely determine molecular orientation, the nature of the moieties, the presence of the surroundings and the temperature; in such circumstances a better understanding of the protein electron transfer (ET) pathway and the mechanism remains a considerable challenge. Here, we report an approach to mechanically drive polypeptide flip-flop motion to achieve a logic gate with ON and OFF states during protein ET. We have calculated the transmission spectra of the peptide-based molecular junctions and observed the hallmarks of electrical current and conductance. The results indicate that peptide ET follows an NC asymmetric process and depends on the amino acid chirality and α-helical handedness. Electron transmission decreases as the number of water molecules increases, and the ET efficiency and its pathway depend on the type of water-bridged H-bonds. Our results provide a rational mechanism for peptide ET and new perspectives on polypeptides as potential candidates in logic nano devices.

  18. Single cell activity reveals direct electron transfer in methanotrophic consortia

    NASA Astrophysics Data System (ADS)

    McGlynn, Shawn E.; Chadwick, Grayson L.; Kempes, Christopher P.; Orphan, Victoria J.

    2015-10-01

    Multicellular assemblages of microorganisms are ubiquitous in nature, and the proximity afforded by aggregation is thought to permit intercellular metabolic coupling that can accommodate otherwise unfavourable reactions. Consortia of methane-oxidizing archaea and sulphate-reducing bacteria are a well-known environmental example of microbial co-aggregation; however, the coupling mechanisms between these paired organisms is not well understood, despite the attention given them because of the global significance of anaerobic methane oxidation. Here we examined the influence of interspecies spatial positioning as it relates to biosynthetic activity within structurally diverse uncultured methane-oxidizing consortia by measuring stable isotope incorporation for individual archaeal and bacterial cells to constrain their potential metabolic interactions. In contrast to conventional models of syntrophy based on the passage of molecular intermediates, cellular activities were found to be independent of both species intermixing and distance between syntrophic partners within consortia. A generalized model of electric conductivity between co-associated archaea and bacteria best fit the empirical data. Combined with the detection of large multi-haem cytochromes in the genomes of methanotrophic archaea and the demonstration of redox-dependent staining of the matrix between cells in consortia, these results provide evidence for syntrophic coupling through direct electron transfer.

  19. Mechanically Controlled Electron Transfer in a Single-Polypeptide Transistor

    PubMed Central

    Sheu, Sheh-Yi; Yang, Dah-Yen

    2017-01-01

    Proteins are of interest in nano-bio electronic devices due to their versatile structures, exquisite functionality and specificity. However, quantum transport measurements produce conflicting results due to technical limitations whereby it is difficult to precisely determine molecular orientation, the nature of the moieties, the presence of the surroundings and the temperature; in such circumstances a better understanding of the protein electron transfer (ET) pathway and the mechanism remains a considerable challenge. Here, we report an approach to mechanically drive polypeptide flip-flop motion to achieve a logic gate with ON and OFF states during protein ET. We have calculated the transmission spectra of the peptide-based molecular junctions and observed the hallmarks of electrical current and conductance. The results indicate that peptide ET follows an NC asymmetric process and depends on the amino acid chirality and α-helical handedness. Electron transmission decreases as the number of water molecules increases, and the ET efficiency and its pathway depend on the type of water-bridged H-bonds. Our results provide a rational mechanism for peptide ET and new perspectives on polypeptides as potential candidates in logic nano devices. PMID:28051140

  20. Observation of a single spin by transferring its coherence to a high level macroscopic pure state

    SciTech Connect

    Kawamura, Minaru

    2014-12-04

    We discuss about quantum measurement of a single spin in a superconducting RF resonator, where amplification of coherence of the spin is enabled by transferring its coherence to the harmonic oscillator in an non-coherent state with high energy level. This quantum amplification allows that a single spin can induce macroscopic current to permits observation of a single spin state in the number and phase uncertainty relation.

  1. Poisson-distributed electron-transfer dynamics from single quantum dots to C60 molecules.

    PubMed

    Song, Nianhui; Zhu, Haiming; Jin, Shengye; Zhan, Wei; Lian, Tianquan

    2011-01-25

    Functional quantum dot (QD)-based nanostructures are often constructed through the self-assembly of QDs with binding partners (molecules or other nanoparticles), a process that leads to a statistical distribution of the number of binding partners. Using single QD fluorescence spectroscopy, we probe this distribution and its effect on the function (electron-transfer dynamics) in QD-C60 complexes. Ensemble-averaged transient absorption and fluorescence decay as well as single QD fluorescence decay measurements show that the QD exciton emission was quenched by electron transfer from the QD to C60 molecules and the electron-transfer rate increases with the C60-to-QD ratio. The electron-transfer rate of single QD-C60 complexes fluctuates with time and varies among different QDs. The standard deviation increases linearly with the average of electron-transfer rates of single QD-C60 complexes, and the distributions of both quantities obey Poisson statistics. The observed distributions of single QD-C60 complexes and ensemble-averaged fluorescence decay kinetics can be described by a model that assumes a Poisson distribution of the number of adsorbed C60 molecules per QD. Our findings suggest that, in self-assembled QD nanostructures, the statistical distribution of the number of adsorbed partners can dominate the distributions of the averages and standard deviation of their interfacial dynamical properties.

  2. Cellular characterization of blastocysts derived from rabbit 4-, 8- and 16-cell embryos and isolated blastomeres cultured in vitro.

    PubMed

    Tao, T; Niemann, H

    2000-04-01

    The purpose of this study was to investigate the developmental potential of isolated rabbit blastomeres under various culture conditions to gain insight into their ability to form the two cell lineages of a viable blastocyst. Intact embryos at the 4-cell, 8-cell, 16-cell stages and blastomeres isolated from 4-, 8- and 16-cell rabbit embryos (1/4, 1/8 or 1/16 blastomeres respectively) were cultured in drops of one of three different media, each supplemented with either fetal calf serum (FCS), bovine serum albumin (BSA) or polyvinyl alcohol (PVA). The effects of the extracellular matrix fibronectin (FN) on the development of isolated rabbit blastomeres were also investigated. Supplementation of the medium with FCS yielded a higher (P < 0.05) proportion of blastocysts than BSA or PVA, predominantly from 1/4 blastomeres. No major differences were found between the three basic culture media. In 1/4, 1/8 or 1/16 blastomeres, blastocyst formation rates were greater (P < 0.05) in groups cultured in matrix-free (54.5, 59.6 and 54.6% respectively) than in FN-coated groups (35.4, 46.0 and 26.1% respectively). Only in blastocysts derived from 1/4 blastomeres, were the numbers of inner cell mass (ICM) and total cells of blastocysts higher (P < 0.05) in FN-coated groups than in matrix-free groups (12.7 +/- 1.1 versus 8.5 +/- 0.7 ICM, 73.8 +/- 3. 7 versus 57.8 +/- 3.3 total cells). The percentage of blastocysts derived from single blastomeres with ICM cells decreased with increasing cell stage of the parent embryos in FN-coated (93.6, 78.3 and 44.0%, respectively) as well as matrix-free groups (96.2, 69.3 and 55.2%). In FN-coated groups, after 96 h (1/4) or 72 h (1/8 and 1/16) of culture, approximately 20-30% of blastomeres did not develop into normal blastocysts but formed sheets with 30-50 cells attached to the bottom of the dishes. These results indicate that the development of rabbit blastomeres shares important characteristics with those from mouse and domestic species and

  3. Comparison of array comparative genomic hybridization and quantitative real-time PCR-based aneuploidy screening of blastocyst biopsies.

    PubMed

    Capalbo, Antonio; Treff, Nathan R; Cimadomo, Danilo; Tao, Xin; Upham, Kathleen; Ubaldi, Filippo Maria; Rienzi, Laura; Scott, Richard T

    2015-07-01

    Comprehensive chromosome screening (CCS) methods are being extensively used to select chromosomally normal embryos in human assisted reproduction. Some concerns related to the stage of analysis and which aneuploidy screening method to use still remain. In this study, the reliability of blastocyst-stage aneuploidy screening and the diagnostic performance of the two mostly used CCS methods (quantitative real-time PCR (qPCR) and array comparative genome hybridization (aCGH)) has been assessed. aCGH aneuploid blastocysts were rebiopsied, blinded, and evaluated by qPCR. Discordant cases were subsequently rebiopsied, blinded, and evaluated by single-nucleotide polymorphism (SNP) array-based CCS. Although 81.7% of embryos showed the same diagnosis when comparing aCGH and qPCR-based CCS, 18.3% (22/120) of embryos gave a discordant result for at least one chromosome. SNP array reanalysis showed that a discordance was reported in ten blastocysts for aCGH, mostly due to false positives, and in four cases for qPCR. The discordant aneuploidy call rate per chromosome was significantly higher for aCGH (5.7%) compared with qPCR (0.6%; P<0.01). To corroborate these findings, 39 embryos were simultaneously biopsied for aCGH and qPCR during blastocyst-stage aneuploidy screening cycles. 35 matched including all 21 euploid embryos. Blinded SNP analysis on rebiopsies of the four embryos matched qPCR. These findings demonstrate the high reliability of diagnosis performed at the blastocyst stage with the use of different CCS methods. However, the application of aCGH can be expected to result in a higher aneuploidy rate than other contemporary methods of CCS.

  4. The single electron transfer chemistry of coals. Final report

    SciTech Connect

    Larsen, J.W.; Flowers, R.A. II

    1994-12-31

    This research addressed electron donar properties and radical reactions in coal. Solid residues from pyridine Soxhlet extractions of Pocahontas No. 3, Upper Freeport, Pittsburgh No. 8, Illinois No. 6 and Wyodak coals were exposed to 4-vinylpyridine vapors and swelled. All of the 4-vinylpyridine could not be removed under vacuum at 100{degree}C. Diffuse reflectance FTIR revealed the presence of poly-(4-vinylpyridine) in the Illinois No. 6 and Wyodak coals. EPR spectra displayed the loss of inertinite radicals in Upper Freeport, Illinois No. 6 and Wyodak residues after exposure to 4-vinylpyridine. There was little change in the vitrinite radical density or environment. The molecule N,N{prime}-Diphenyl-p-phenylene diamine (DPPD) was exposed to the solid residues from pyridine Soxhlet extractions of the above coals. Diffuse reflectance FTIR failed to detect the imine product from radical reaction with DPPD. EPR spectra displayed the loss of inertinite radicals in Upper Freeport and Wyodak residues. 7,7,8,8-Tetracyanoquinodimethane (TCNQ) and Tetracyanoethylene (TCNE) were deposited into coals in pyridine. FTIR indicated complete conversion of TCNQ to a material with a singly occupied LUMO. In TCNE the LUMO is about 30% occupied. TCNQ and TCNE were deposited into the pyridine extracts and residues of Illinois No. 6 and Pittsburgh No. 8 coals. Only a small amount of the TCNQ and TCNE displayed nitrile shifts in the IR spectrum of a material with an occupied LUMO. It has been concluded that TCNQ must be part of the aromatic stacks in coal and the TCNQ LUMO is part of an extended band.

  5. Elective single-embryo transfer in oocyte donation programmes: Should it be the rule?

    PubMed

    Clua, Elisabet; Tur, Rosa; Coroleu, Buenaventura; Boada, Montse; Rodríguez, I; Barri, Pedro N; Veiga, Anna

    2012-12-01

    The aim of this study is to compare the cumulative clinical pregnancy and live birth rates (fresh embryo transfers followed by frozen-thawed embryo transfers from the same stimulated cycle) between single-embryo transfer (SET) and double-embryo transfer (DET) in an oocyte donation programme. A retrospective analysis of the outcome in 1139 recipient fresh cycles (1073 from DET and 66 from SET) with at least three available embryos for transfer was performed. The clinical pregnancy rates were similar after SET (45.5%, 30/66) and DET (57.1%, 613/1073), whereas the multiple pregnancy rate was 0% and 39.5% for SET and DET, respectively. After evaluating the results using the Kaplan-Meier survival analysis in a period of 1 year, no statistically significant differences were observed in the cumulative clinical pregnancy and live birth rates (SET 82.8% and 76.4% versus DET 77.2% and 63.7%). The results indicate that for women who have at least three available embryos in oocyte donation programmes, one single embryo should be transferred as no significant decrease in the success rate is observed and multiple pregnancy can be avoided. Clinical pregnancy rate is higher when transferring two embryos compared with one. However, this also results in a higher incidence of twin pregnancy, which is associated with increased obstetric and perinatal risks. The aim of this study was to compare the cumulative clinical pregnancy and live birth rates (fresh embryo transfers followed by frozen-thawed embryo transfers from the same stimulated cycle) between single-embryo transfer (SET) and double-embryo transfer (DET) cycles in our oocyte donation programme. A retrospective analysis of the outcome in 1139 recipient fresh cycles (1076 from DET and 66 from SET) with at least three available embryos for transfer was performed. The clinical pregnancy rates were similar after SET (45.5%, 30/66) and DET (57.1%, 613/1073), whereas the multiple pregnancy rate was 0% and 39.5% for SET and DET

  6. Differential expression of oxygen-regulated genes in bovine blastocysts.

    PubMed

    Harvey, A J; Navarrete Santos, A; Kirstein, M; Kind, K L; Fischer, B; Thompson, J G

    2007-03-01

    Low oxygen conditions (2%) during post-compaction culture of bovine blastocysts improve embryo quality, which is associated with a small yet significant increase in the expression of glucose transporter 1 (GLUT-1), suggesting a role of oxygen in embryo development mediated through oxygen-sensitive gene expression. However, bovine embryos to at least the blastocyst stage lack a key regulator of oxygen-sensitive gene expression, hypoxia-inducible factor 1alpha (HIF1alpha). A second, less well-characterized protein (HIF2alpha) is, however, detectable from the 8-cell stage of development. Here we use differential display to determine additional gene targets in bovine embryos in response to low oxygen conditions. While development to the blastocyst stage was unaffected by the oxygen concentration used during post-compaction culture, differential display identified oxygen-regulation of myotrophin and anaphase promoting complex 1 expression, with significantly lower levels observed following culture under 20% oxygen than 2% oxygen. These results further support the hypothesis that the level of gene expression of specific transcripts by bovine embryos alters in response to changes in the oxygen environment post-compaction. Specifically, we have identified two oxygen-sensitive genes that are potentially regulated by HIF2 in the bovine blastocyst.

  7. Monitoring Conformational Dynamics with Single-Molecule Fluorescence Energy Transfer: Applications in Nucleosome Remodeling

    PubMed Central

    Deindl, Sebastian; Zhuang, Xiaowei

    2016-01-01

    Due to its ability to track distance changes within individual molecules or molecular complexes on the nanometer scale and in real time, single-molecule fluorescence resonance energy transfer (single-molecule FRET) is a powerful tool to tackle a wide range of important biological questions. Using our recently developed single-molecule FRET assay to monitor nucleosome translocation as an illustrative example, we describe here in detail how to set up, carry out, and analyze single-molecule FRET experiments that provide time-dependent information on biomolecular processes. PMID:22929765

  8. Time-resolved energy transfer from single chloride-terminated nanocrystals to graphene

    SciTech Connect

    Ajayi, O. A. E-mail: cww2104@columbia.edu; Wong, C. W. E-mail: cww2104@columbia.edu; Anderson, N. C.; Wolcott, A.; Owen, J. S.; Cotlet, M.; Petrone, N.; Hone, J.; Gu, T.; Gesuele, F.

    2014-04-28

    We examine the time-resolved resonance energy transfer of excitons from single n-butyl amine-bound, chloride-terminated nanocrystals to two-dimensional graphene through time-correlated single photon counting. The radiative biexponential lifetime kinetics and blinking statistics of the individual surface-modified nanocrystal elucidate the non-radiative decay channels. Blinking modification as well as a 4× reduction in spontaneous emission were observed with the short chloride and n-butylamine ligands, probing the energy transfer pathways for the development of graphene-nanocrystal nanophotonic devices.

  9. How was the proton transfer process in bis-3, 6-(2- benzoxazolyl)-pyrocatechol, single or double proton transfer?

    PubMed Central

    Zhang, Yongjia; Sun, Mengtao; Li, Yongqing

    2016-01-01

    A theoretical analysis of proton transfer process for the symmetric systems with two intramolecular hydrogen bonds, bis-3,6-(2-benzoxazolyl)-pyrocatechol(BBPC) in hexane solvent, has been researched. In this study, we utilized ωB97X-D/ 6-311 + g (d,p) and B3LYP/6-31 + G(d) two procedures calculating the foremost bond length and bond angle, respectively. Our calculations demonstrate the two intramolecular hydrogen bonds were strengthened in S1 state, thus the proton transfer reaction can be facilitated. Furthermore, the calculated IR vibrational spectra confirmed hydrogen bonds were enhanced in S1 state. We found three local minima A B and C from the potential energy surfaces (PESs) on the S1 state, and the energy of B point and C point are identical. A new ESIPT mechanism has been proposed that was not equal to the previous conclusions. The new ESIPT mechanism elucidates that single proton transfer more likely occurs in the symmetric BBPC molecule in comparison with the double proton transfer reaction. And the frontier molecular orbitals(MOs) further illustrate the trend of ESIPT reaction. PMID:27157994

  10. How was the proton transfer process in bis-3, 6-(2- benzoxazolyl)-pyrocatechol, single or double proton transfer?

    NASA Astrophysics Data System (ADS)

    Zhang, Yongjia; Sun, Mengtao; Li, Yongqing

    2016-05-01

    A theoretical analysis of proton transfer process for the symmetric systems with two intramolecular hydrogen bonds, bis-3,6-(2-benzoxazolyl)-pyrocatechol(BBPC) in hexane solvent, has been researched. In this study, we utilized ωB97X-D/ 6-311 + g (d,p) and B3LYP/6-31 + G(d) two procedures calculating the foremost bond length and bond angle, respectively. Our calculations demonstrate the two intramolecular hydrogen bonds were strengthened in S1 state, thus the proton transfer reaction can be facilitated. Furthermore, the calculated IR vibrational spectra confirmed hydrogen bonds were enhanced in S1 state. We found three local minima A B and C from the potential energy surfaces (PESs) on the S1 state, and the energy of B point and C point are identical. A new ESIPT mechanism has been proposed that was not equal to the previous conclusions. The new ESIPT mechanism elucidates that single proton transfer more likely occurs in the symmetric BBPC molecule in comparison with the double proton transfer reaction. And the frontier molecular orbitals(MOs) further illustrate the trend of ESIPT reaction.

  11. Cryopreservation of Day 8 equine embryos after blastocyst micromanipulation and vitrification.

    PubMed

    Diaz, Fabian; Bondiolli, Kenneth; Paccamonti, Dale; Gentry, Glen T

    2016-03-15

    capsule loss (70%) compared with the indirect introduction treatment group (31%). The pregnancy rate after transfer of vitrified expanded Grade 1 blastocysts using the indirect introduction method was 83% (5/6). Three pregnancies were allowed to continue to term and resulted in the birth of three healthy foals. The vitrification protocol used in this study has the potential to become a key tool for the successful cryopreservation of equine expanded blastocysts.

  12. Cryotolerance of porcine in vitro-produced blastocysts relies on blastocyst stage and length of in vitro culture prior to vitrification.

    PubMed

    Morató, Roser; Castillo-Martín, Míriam; Yeste, Marc; Bonet, Sergi

    2014-12-04

    The aim of our study was to assess whether the cryotolerance of in vitro-produced embryos could be influenced by the length of in vitro culture and size of blastocoel cavity before vitrification, using the pig as a model. For this purpose we analysed the cryoresistance and apoptosis rate of blastocysts at different stages of development as derived on Day 5 and 6 of in vitro culture. Blastocysts were subsequently vitrified, warmed and cultured for 24h. Re-expansion rates were recorded at 3 and 24h and total cell number and apoptotic cells were determined at 24h. Day-6 blastocysts showed the highest rates of survival after warming, which indicates higher quality compared with Day-5 blastocysts. Higher re-expansion rates were observed for expanded blastocysts and those in the process of hatching when compared with early blastocysts. Total cell number and apoptotic cells were affected by blastocyst stage, vitrification-warming procedures and length of in vitro culture, as expanding and hatching-hatched blastocysts from Day 6 presented higher percentages of apoptotic cells than fresh blastocysts and blastocysts vitrified at Day 5. Our findings suggest that the cryotop vitrification method is useful for the cryopreservation of porcine blastocysts presenting a high degree of expansion, particularly when vitrification is performed after 6 days of in vitro culture. Furthermore, these results show that faster embryo development underlies higher blastocyst cryotolerance and provide evidence that blastocoel cavity expansion before vitrification is a reliable index of in vitro-produced embryo quality and developmental potential.

  13. Evidence that Additions of Grignard Reagents to Aliphatic Aldehydes Do Not Involve Single-Electron-Transfer Processes.

    PubMed

    Otte, Douglas A L; Woerpel, K A

    2015-08-07

    Addition of allylmagnesium reagents to an aliphatic aldehyde bearing a radical clock gave only addition products and no evidence of ring-opened products that would suggest single-electron-transfer reactions. The analogous Barbier reaction also did not provide evidence for a single-electron-transfer mechanism in the addition step. Other Grignard reagents (methyl-, vinyl-, t-Bu-, and triphenylmethylmagnesium halides) also do not appear to add to an alkyl aldehyde by a single-electron-transfer mechanism.

  14. Evenly transferred single-layered graphene membrane assisted by strong substrate adhesion

    NASA Astrophysics Data System (ADS)

    Park, Seongjae; Kim, Hoijoon; Seol, Daehee; Park, Taejin; Leem, Mirine; Ha, Hyunwoo; An, Hyesung; You Kim, Hyun; Jeong, Seong-Jun; Park, Seongjun; Kim, Hyoungsub; Kim, Yunseok

    2017-04-01

    We explored the transfer of a single-layered graphene membrane assisted by substrate adhesion. A relatively larger adhesion force was measured on the SiO2 substrate compared with its van der Waals contribution, which is expected to result from the additional contribution of the chemical bonding force. Density functional theory calculations verified that the strong adhesion force was indeed accompanied by chemical bonding. The transfer of single-layered graphene and subsequent deposition of the dielectric layer were best performed on the SiO2 substrate exhibiting a larger adhesion force. This study suggests the selection and/or modification of the underlying substrate for proper transfer of graphene as well as other 2D materials similar to graphene.

  15. Research on urban public traffic network with multi-weights based on single bus transfer junction

    NASA Astrophysics Data System (ADS)

    An, Xin-lei; Zhang, Li; Zhang, Jian-gang

    2015-10-01

    Regarding single bus transfer junction as a research object, this paper constructs the urban traffic network models with multi-weights taking different bus lines in bus transfer junction as the network nodes, that is, the urban traffic network with multi-weights is given different properties weights at every edge. According to the method of network split, the complex network with multi-weights is split into several different single weighted complex networks. Then, we study the global synchronization of the new network model by changing congestion degrees, transfers coefficient and passenger flow density between different bus lines. Finally, analytical and simulated results are given to show the impact of different properties weights to the public traffic network balance.

  16. Evenly transferred single-layered graphene membrane assisted by strong substrate adhesion.

    PubMed

    Park, Seongjae; Kim, Hoijoon; Seol, Daehee; Park, Taejin; Leem, Mirine; Ha, Hyunwoo; An, Hyesung; You Kim, Hyun; Jeong, Seong-Jun; Park, Seongjun; Kim, Hyoungsub; Kim, Yunseok

    2017-04-07

    We explored the transfer of a single-layered graphene membrane assisted by substrate adhesion. A relatively larger adhesion force was measured on the SiO2 substrate compared with its van der Waals contribution, which is expected to result from the additional contribution of the chemical bonding force. Density functional theory calculations verified that the strong adhesion force was indeed accompanied by chemical bonding. The transfer of single-layered graphene and subsequent deposition of the dielectric layer were best performed on the SiO2 substrate exhibiting a larger adhesion force. This study suggests the selection and/or modification of the underlying substrate for proper transfer of graphene as well as other 2D materials similar to graphene.

  17. Polarization Transfer in Wide-Angle Compton Scattering and Single-Pion Photoproduction from the Proton

    NASA Astrophysics Data System (ADS)

    Fanelli, C.; Cisbani, E.; Hamilton, D. J.; Salmé, G.; Wojtsekhowski, B.; Ahmidouch, A.; Annand, J. R. M.; Baghdasaryan, H.; Beaufait, J.; Bosted, P.; Brash, E. J.; Butuceanu, C.; Carter, P.; Christy, E.; Chudakov, E.; Danagoulian, S.; Day, D.; Degtyarenko, P.; Ent, R.; Fenker, H.; Fowler, M.; Frlez, E.; Gaskell, D.; Gilman, R.; Horn, T.; Huber, G. M.; de Jager, C. W.; Jensen, E.; Jones, M. K.; Kelleher, A.; Keppel, C.; Khandaker, M.; Kohl, M.; Kumbartzki, G.; Lassiter, S.; Li, Y.; Lindgren, R.; Lovelace, H.; Luo, W.; Mack, D.; Mamyan, V.; Margaziotis, D. J.; Markowitz, P.; Maxwell, J.; Mbianda, G.; Meekins, D.; Meziane, M.; Miller, J.; Mkrtchyan, A.; Mkrtchyan, H.; Mulholland, J.; Nelyubin, V.; Pentchev, L.; Perdrisat, C. F.; Piasetzky, E.; Prok, Y.; Puckett, A. J. R.; Punjabi, V.; Shabestari, M.; Shahinyan, A.; Slifer, K.; Smith, G.; Solvignon, P.; Subedi, R.; Wesselmann, F. R.; Wood, S.; Ye, Z.; Zheng, X.

    2015-10-01

    Wide-angle exclusive Compton scattering and single-pion photoproduction from the proton have been investigated via measurement of the polarization transfer from a circularly polarized photon beam to the recoil proton. The wide-angle Compton scattering polarization transfer was analyzed at an incident photon energy of 3.7 GeV at a proton scattering angle of θcmp=70 ° . The longitudinal transfer KLL, measured to be 0.645 ±0.059 ±0.048 , where the first error is statistical and the second is systematic, has the same sign as predicted for the reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton. However, the observed value is ˜3 times larger than predicted by the generalized-parton-distribution-based calculations, which indicates a significant unknown contribution to the scattering amplitude.

  18. Polarization Transfer in Wide-Angle Compton Scattering and Single-Pion Photoproduction from the Proton.

    PubMed

    Fanelli, C; Cisbani, E; Hamilton, D J; Salmé, G; Wojtsekhowski, B; Ahmidouch, A; Annand, J R M; Baghdasaryan, H; Beaufait, J; Bosted, P; Brash, E J; Butuceanu, C; Carter, P; Christy, E; Chudakov, E; Danagoulian, S; Day, D; Degtyarenko, P; Ent, R; Fenker, H; Fowler, M; Frlez, E; Gaskell, D; Gilman, R; Horn, T; Huber, G M; de Jager, C W; Jensen, E; Jones, M K; Kelleher, A; Keppel, C; Khandaker, M; Kohl, M; Kumbartzki, G; Lassiter, S; Li, Y; Lindgren, R; Lovelace, H; Luo, W; Mack, D; Mamyan, V; Margaziotis, D J; Markowitz, P; Maxwell, J; Mbianda, G; Meekins, D; Meziane, M; Miller, J; Mkrtchyan, A; Mkrtchyan, H; Mulholland, J; Nelyubin, V; Pentchev, L; Perdrisat, C F; Piasetzky, E; Prok, Y; Puckett, A J R; Punjabi, V; Shabestari, M; Shahinyan, A; Slifer, K; Smith, G; Solvignon, P; Subedi, R; Wesselmann, F R; Wood, S; Ye, Z; Zheng, X

    2015-10-09

    Wide-angle exclusive Compton scattering and single-pion photoproduction from the proton have been investigated via measurement of the polarization transfer from a circularly polarized photon beam to the recoil proton. The wide-angle Compton scattering polarization transfer was analyzed at an incident photon energy of 3.7 GeV at a proton scattering angle of θ_{cm}^{p}=70°. The longitudinal transfer K_{LL}, measured to be 0.645±0.059±0.048, where the first error is statistical and the second is systematic, has the same sign as predicted for the reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton. However, the observed value is ~3 times larger than predicted by the generalized-parton-distribution-based calculations, which indicates a significant unknown contribution to the scattering amplitude.

  19. Polarization transfer in wide-angle Compton scattering and single-pion photoproduction from the proton

    SciTech Connect

    Fanelli, Cristiano V.

    2015-10-06

    Wide-angle exclusive Compton scattering and single-pion photoproduction from the proton have been investigated via measurement of the polarization transfer from a circularly polarized photon beam to the recoil proton. The WACS polarization transfer was analyzed at an incident photon energy of 3.7 GeV at a proton scattering angle of θPcm = 70°. The longitudinal transfer KLL, measured to be 0.645 ± 0.059 ± 0.048, where the first error is statistical and the second is systematic, has the same sign as predicted for the reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton. However, the observed value is ~3 times larger than predicted by the GPD-based calculations, which indicates a significant unknown contribution to the scattering amplitude.

  20. Polarization transfer in wide-angle Compton scattering and single-pion photoproduction from the proton

    DOE PAGES

    Fanelli, Cristiano V.

    2015-10-06

    Wide-angle exclusive Compton scattering and single-pion photoproduction from the proton have been investigated via measurement of the polarization transfer from a circularly polarized photon beam to the recoil proton. The WACS polarization transfer was analyzed at an incident photon energy of 3.7 GeV at a proton scattering angle of θPcm = 70°. The longitudinal transfer KLL, measured to be 0.645 ± 0.059 ± 0.048, where the first error is statistical and the second is systematic, has the same sign as predicted for the reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton.more » However, the observed value is ~3 times larger than predicted by the GPD-based calculations, which indicates a significant unknown contribution to the scattering amplitude.« less

  1. Energy Excitation Transfer in a Single Molecule of Poly(p-phenylene vinylene)

    NASA Astrophysics Data System (ADS)

    Claudio, Gil; Bittner, Eric

    2002-03-01

    Energy excitation transfer has been shown to occur in conducting polymers such as MEH-PPV [Synth. Met. 116, 35 (2001)]. Initially excited chromophores, which are short oligomers of the polymer, non-radiatively transfer their excitation to longer oligomers of lower energy. We calculate the dynamics of this migration in an ensemble of PPV chains generated by a random growth algorithm [J. Chem. Phys. 115, 9585 (2001)] using the rates described by Förster theory. The proximity of nearby chromophores within the polymer allows for the efficient non-radiative within a single polymer. The great difference in rates between interchain and intrachain transfer also impedes the isolated chromophore from further transfering its excitation to and thus fluoresce with an energy that is red-shifted from the initial excitation.

  2. Photoluminescence enhancement of aligned arrays of single-walled carbon nanotubes by polymer transfer

    NASA Astrophysics Data System (ADS)

    Schweiger, Manuel; Zakharko, Yuriy; Gannott, Florentina; Grimm, Stefan B.; Zaumseil, Jana

    2015-10-01

    The photoluminescence of as-grown, aligned single-walled carbon nanotubes (SWNTs) on quartz is strongly quenched and barely detectable. Here we show that transferring these SWNTs to another substrate such as clean quartz or glass increases their emission efficiency by up to two orders of magnitude. By statistical analysis of large nanotube arrays we show at what point of the transfer process the emission enhancement occurs and how it depends on the receiving substrate and the employed transfer polymer. We find that hydrophobic polystyrene (PS) as the transfer polymer results in higher photoluminescence enhancement than the more hydrophilic poly(methyl methacrylate) (PMMA). Possible mechanisms for this enhancement such as strain relief, disruption of the strong interaction of SWNTs with the substrate and localized emissive states are discussed.The photoluminescence of as-grown, aligned single-walled carbon nanotubes (SWNTs) on quartz is strongly quenched and barely detectable. Here we show that transferring these SWNTs to another substrate such as clean quartz or glass increases their emission efficiency by up to two orders of magnitude. By statistical analysis of large nanotube arrays we show at what point of the transfer process the emission enhancement occurs and how it depends on the receiving substrate and the employed transfer polymer. We find that hydrophobic polystyrene (PS) as the transfer polymer results in higher photoluminescence enhancement than the more hydrophilic poly(methyl methacrylate) (PMMA). Possible mechanisms for this enhancement such as strain relief, disruption of the strong interaction of SWNTs with the substrate and localized emissive states are discussed. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr05163k

  3. Analysis of blastocyst culture of discarded embryos and its significance for establishing human embryonic stem cell lines.

    PubMed

    Wang, Fang; Kong, Hui-Juan; Kan, Quan-Cheng; Liang, Ju-Yan; Zhao, Fang; Bai, Ai-Hong; Li, Peng-Fen; Sun, Ying-Pu

    2012-12-01

    In recent years, applications of stem cells have already involved in all domains of life science and biomedicine. People try to establish human embryonic stem cell lines (hESCs) in order to carry out hESC-related studies. In this study, we explored what embryos are conducive to the establishment of hESCs. The discarded embryos from in vitro fertilization-embryo transfer (IVF-ET) cycles were sequentially incubated into blastocysts, and then the inner cell mass (ICM) was isolated and incubated in the mixed feeder layer. The cell lines which underwent serial passage were identified. After a total of 1,725 discarded embryos from 754 patients were incubated, 448 blastocysts were formed with 123 high-quality blastocysts. The blastulation rate was significantly higher in the discarded embryos with non-pronucleus (0PN) or 1PN than in the discarded embryos with 2PN or ≥3PN. The blastulation rate of the D3 embryos with 7-9 blastomeres was higher. Among the originally incubated 389 ICMs, 22 hESCs with normal karyotype were established, and identified to be ESCs. Therefore, in establishing hESCs with discarded embryos, D(3) 0PN or 1PN embryos with 7-9 blastomeres should be first selected, because they can improve high-quality blastulation rate which can increase the efficiency of hESC establishment.

  4. Automatic segmentation of trophectoderm in microscopic images of human blastocysts.

    PubMed

    Singh, Amarjot; Au, Jason; Saeedi, Parvaneh; Havelock, Jon

    2015-01-01

    Accurate assessment of embryos viability is an extremely important task in the optimization of in vitro fertilization treatment outcome. One of the common ways of assessing the quality of a human embryo is grading it on its fifth day of development based on morphological quality of its three main components (Trophectoderm, Inner Cell Mass, and the level of expansion or the thickness of its Zona Pellucida). In this study, we propose a fully automatic method for segmentation and measurement of TE region of blastocysts (day-5 human embryos). Here, we eliminate the inhomogeneities of the blastocysts surface using the Retinex theory and further apply a level-set algorithm to segment the TE regions. We have tested our method on a dataset of 85 images and have been able to achieve a segmentation accuracy of 84.6% for grade A, 89.0% for grade B, and 91.7% for grade C embryos.

  5. Single mutations that redirect internal proton transfer in the ba3 oxidase from Thermus thermophilus.

    PubMed

    Smirnova, Irina; Chang, Hsin-Yang; von Ballmoos, Christoph; Ädelroth, Pia; Gennis, Robert B; Brzezinski, Peter

    2013-10-08

    The ba3-type cytochrome c oxidase from Thermus thermophilus is a membrane-bound proton pump. Results from earlier studies have shown that with the aa3-type oxidases proton uptake to the catalytic site and "pump site" occurs simultaneously. However, with ba3 oxidase the pump site is loaded before proton transfer to the catalytic site because the proton transfer to the latter is slower than that with the aa3 oxidases. In addition, the timing of formation and decay of catalytic intermediates is different in the two types of oxidases. In the present study, we have investigated two mutant ba3 CytcOs in which residues of the proton pathway leading to the catalytic site as well as the pump site were exchanged, Thr312Val and Tyr244Phe. Even though ba3 CytcO uses only a single proton pathway for transfer of the substrate and "pumped" protons, the amino-acid residue substitutions had distinctly different effects on the kinetics of proton transfer to the catalytic site and the pump site. The results indicate that the rates of these reactions can be modified independently by replacement of single residues within the proton pathway. Furthermore, the data suggest that the Thr312Val and Tyr244Phe mutations interfere with a structural rearrangement in the proton pathway that is rate limiting for proton transfer to the catalytic site.

  6. Near-infrared fluorescent single walled carbon nanotube-chitosan composite: Interfacial strain transfer efficiency assessment

    NASA Astrophysics Data System (ADS)

    Mol Menamparambath, Mini; Arabale, Girish; Nikolaev, Pavel; Baik, Seunghyun; Arepalli, Sivaram

    2013-04-01

    Effective load transfer at the single walled carbon nanotube (SWCNT)-polymer interface is most desirable for mechanically reinforced polymer composites. Versatile layer-by-layer assembly technique achieved dispersion and uniform distribution of sodium carboxymethylcellulose (CMC)-solubilized SWCNTs within the polymer matrix. Electrostatic interaction between positively charged chitosan and negatively charged CMC facilitates design of an optically active biocompatible nanocomposite. Interfacial strain transfer efficiency of SWCNT-chitosan nanocomposite was assessed via SWCNT Raman and photoluminescence band shifts under uniaxial strain. Photoluminescence peak shift rates of individual semiconducting SWCNTs were investigated and compared with tight binding model calculations.

  7. Large-Area Dry Transfer of Single-Crystalline Epitaxial Bismuth Thin Films.

    PubMed

    Walker, Emily S; Na, Seung Ryul; Jung, Daehwan; March, Stephen D; Kim, Joon-Seok; Trivedi, Tanuj; Li, Wei; Tao, Li; Lee, Minjoo L; Liechti, Kenneth M; Akinwande, Deji; Bank, Seth R

    2016-11-09

    We report the first direct dry transfer of a single-crystalline thin film grown by molecular beam epitaxy. A double cantilever beam fracture technique was used to transfer epitaxial bismuth thin films grown on silicon (111) to silicon strips coated with epoxy. The transferred bismuth films retained electrical, optical, and structural properties comparable to the as-grown epitaxial films. Additionally, we isolated the bismuth thin films on freestanding flexible cured-epoxy post-transfer. The adhesion energy at the bismuth/silicon interface was measured to be ∼1 J/m(2), comparable to that of exfoliated and wet transferred graphene. This low adhesion energy and ease of transfer is unexpected for an epitaxially grown film and may enable the study of bismuth's unique electronic and spintronic properties on arbitrary substrates. Moreover, this method suggests a route to integrate other group-V epitaxial films (i.e., phosphorus) with arbitrary substrates, as well as potentially to isolate bismuthene, the atomic thin-film limit of bismuth.

  8. Evidence of a pluripotent human embryonic stem cell line derived from a cloned blastocyst.

    PubMed

    Hwang, Woo Suk; Ryu, Young June; Park, Jong Hyuk; Park, Eul Soon; Lee, Eu Gene; Koo, Ja Min; Jeon, Hyun Yong; Lee, Byeong Chun; Kang, Sung Keun; Kim, Sun Jong; Ahn, Curie; Hwang, Jung Hye; Park, Ky Young; Cibelli, Jose B; Moon, Shin Yong

    2004-03-12

    Somatic cell nuclear transfer (SCNT) technology has recently been used to generate animals with a common genetic composition. In this study, we report the derivation of a pluripotent embryonic stem (ES) cell line (SCNT-hES-1) from a cloned human blastocyst. The SCNT-hES-1 cells displayed typical ES cell morphology and cell surface markers and were capable of differentiating into embryoid bodies in vitro and of forming teratomas in vivo containing cell derivatives from all three embryonic germ layers in severe combined immunodeficient mice. After continuous proliferation for more than 70 passages, SCNT-hES-1 cells maintained normal karyotypes and were genetically identical to the somatic nuclear donor cells. Although we cannot completely exclude the possibility that the cells had a parthenogenetic origin, imprinting analyses support a SCNT origin of the derived human ES cells.

  9. A combined treatment of ionomycin with ethanol improves blastocyst development of bovine oocytes harvested from stored ovaries and microinjected with spermatozoa.

    PubMed

    Abdalla, H; Shimoda, M; Hirabayashi, M; Hochi, S

    2009-09-01

    Regardless of the presence of sperm-borne oocyte-activating factors, activation of bovine oocytes with exogenous activation stimuli is required for further development after intracytoplasmic sperm injection (ICSI). The current study was designed to develop a new activation regimen for improving the blastocyst yield after ICSI of bovine oocytes harvested from ovaries stored at 10 to 12 degrees C for 24h. After ICSI, oocytes were treated with 5microM ionomycin for 5 min, 7% ethanol for 5 or 10min, ionomycin followed by ethanol (5 or 10 min), ionomycin followed by 10 microg/mL cycloheximide for 5h, or ionomycin followed by 1.9 mM 6-dimethylaminopurine for 3h. Across the activation regimens, the cleavage rates of ICSI oocytes (45% to 77%) were higher than those of parthenogenetically activated oocytes (11% to 21%; P<0.05). Activating the ICSI oocytes with ionomycin plus ethanol improved the blastocyst yield (29% to 30%) compared with that of nontreated oocytes (12%; P<0.05), but the other regimens did not improve the blastocyst yield (9% to 18%; P>0.05). Higher blastocyst yields were due to increasing the proportion of ICSI oocytes that passed through the early postfertilization events until cleavage. None of the regimens have any adverse effect on the quality of the blastocysts regarding the total cell number or the proportion of the inner cell mass cells. Thus, a new activation regimen using two triggers for single calcium increase effectively improved blastocyst yield after bovine ICSI using oocytes harvested from stored ovaries.

  10. Optimal state transfer of a single dissipative two-level system

    NASA Astrophysics Data System (ADS)

    Jirari, Hamza; Wu, Ning

    2016-04-01

    Optimal state transfer of a single two-level system (TLS) coupled to an Ohmic boson bath via off-diagonal TLS-bath coupling is studied by using optimal control theory. In the weak system-bath coupling regime where the time-dependent Bloch-Redfield formalism is applicable, we obtain the Bloch equation to probe the evolution of the dissipative TLS in the presence of a time-dependent external control field. By using the automatic differentiation technique to compute the gradient for the cost functional, we calculate the optimal transfer integral profile that can achieve an ideal transfer within a dimer system in the Fenna-Matthews-Olson (FMO) model. The robustness of the control profile against temperature variation is also analyzed.

  11. Transfer doping of single isolated nanodiamonds, studied by scanning probe microscopy techniques.

    PubMed

    Bolker, Asaf; Saguy, Cecile; Kalish, Rafi

    2014-09-26

    The transfer doping of diamond surfaces has been applied in various novel two-dimensional electronic devices. Its extension to nanodiamonds (ND) is essential for ND-based applications in many fields. In particular, understanding the influence of the crystallite size on transfer doping is desirable. Here, we report the results of a detailed study of the electronic energetic band structure of single, isolated transfer-doped nanodiamonds with nanometric resolution using a combination of scanning tunneling spectroscopy and Kelvin force microscopy measurements. The results show how the band gap, the valence band maximum, the electron affinity and the work function all depend on the ND's size and nanoparticle surface properties. The present analysis, which combines information from both scanning tunneling spectroscopy and Kelvin force microscopy, should be applicable to any nanoparticle or surface that can be measured with scanning probe techniques.

  12. Transfer doping of single isolated nanodiamonds, studied by scanning probe microscopy techniques

    NASA Astrophysics Data System (ADS)

    Bolker, Asaf; Saguy, Cecile; Kalish, Rafi

    2014-09-01

    The transfer doping of diamond surfaces has been applied in various novel two-dimensional electronic devices. Its extension to nanodiamonds (ND) is essential for ND-based applications in many fields. In particular, understanding the influence of the crystallite size on transfer doping is desirable. Here, we report the results of a detailed study of the electronic energetic band structure of single, isolated transfer-doped nanodiamonds with nanometric resolution using a combination of scanning tunneling spectroscopy and Kelvin force microscopy measurements. The results show how the band gap, the valence band maximum, the electron affinity and the work function all depend on the ND’s size and nanoparticle surface properties. The present analysis, which combines information from both scanning tunneling spectroscopy and Kelvin force microscopy, should be applicable to any nanoparticle or surface that can be measured with scanning probe techniques.

  13. Single Neutron Transfer Experiments Close to the r-Process Path

    SciTech Connect

    Grzywacz-Jones, Kate L; Adekola, Aderemi S; Bardayan, Daniel W; Blackmon, Jeff C; Chae, Kyung Yuk; Chipps, K.; Cizewski, Jolie; Dean, David Jarvis; Erikson, Luke; Fitzgerald, R. P.; Gaddis, A. L.; Greife, U.; Harlin, Christopher W; Hatarik, Robert; Howard, Joshua A; Johnson, Micah; Kozub, R. L.; Liang, J Felix; Livesay, Jake; Ma, Zhanwen; Moazen, Brian; O'Malley, Patrick; Nesaraja, Caroline D; Pain, S. D.; Patterson, N. P.; Paulauskas, Stanley V; Shapira, Dan; ShrinerJr., J. F.; Sissom, D. J.; Smith, Michael Scott; Swan, T. P.; Thomas, J. S.

    2007-01-01

    The first measurements using the (d, p) transfer reaction to study single- particle states in nuclei on the expected r-process path have been made at the Holifield Radioactive Ion Beam Facility. The shell closure at N = 50 has been crossed using the 82Ge(d, p) and 84Se(d, p) reactions. The prop- erties of the lowest-lying states have been determined. Furthermore, the 132Sn(d, p) reaction has been used for the first time to populate single- particle states in 133Sn.

  14. Cathodic Aromatic C,C Cross-Coupling Reaction via Single Electron Transfer Pathway.

    PubMed

    Qu, Yang; Tateno, Hiroyuki; Matsumura, Yoshimasa; Kashiwagi, Tsuneo; Atobe, Mahito

    2017-03-07

    We have successfully developed a novel cathodic cross-coupling reaction of aryl halides with arenes. Utilization of the cathodic single electron transfer (SET) mechanism for activation of aryl halides enables the cross-coupling reaction to proceed without the need for any transition metal catalysts or single electron donors in a mild condition. The SET from a cathode to an aryl halide initiates a radical chain by giving an anion radical of the aryl halide. The following propagation cycle also consists entirely of anion radical intermediates.

  15. Single lung alveolar volume and gas transfer: effect of expansion of the other lung.

    PubMed Central

    Johansen, B.; Bjørtuft, O.

    1994-01-01

    BACKGROUND--Temporary occlusion of one mainstem bronchus permits measurement of single lung function. A previous study suggested that the volume at which one lung is occluded may influence the expansion of the other. The effect of ipsilateral occlusion volume on the contralateral effective alveolar volume (VA, EFF,SL), inspired volume (VI,SL), single breath estimated residual volume (RVSB,SL), carbon monoxide (CO) transfer (TLCO,SL) and transfer coefficient (KCO,SL) has been examined. METHODS--Single breath measurements of CO transfer were made in duplicate in 12 healthy subjects aged 19-44 years, without and during occlusion of one mainstem bronchus by a balloon at RV and at total lung capacity (TLC). RESULTS--Mean VA,EFF,SL, VI,SL, and TLCO,SL were lower during occlusion at RV than during occlusion at TLC (2.84 v 3.26 l; 2.18 v 2.54 l; and 4.70 v 5.51 mmol/kPa/min respectively). RVSB,SL was independent of occlusion volume and KCO,SL not different from the KCO of both lungs (KCO,BL). Single lung values during occlusion at TLC were fairly reproducible and were, except for KCO,SL, approximately half the values for both lungs. During occlusion at RV the second TLCO,SL and KCO,SL were lower than the first. CONCLUSIONS--Occlusion of one lung permits reliable determinations of gas transfer indices of the other, provided the lung is occluded at TLC. Occlusion at RV significantly reduces VA,EFF,SL, and hence TLCO,SL, but does not affect KCO,SL of the other lung. PMID:7878561

  16. Heat transfer characteristics of a single circular air jet impinging on a concave hemispherical shell

    NASA Technical Reports Server (NTRS)

    Livingood, J. N. B.; Gauntner, J. W.

    1973-01-01

    An experimental study was made of the local and average heat-transfer characteristics of a single turbulent air jet impinging on the concave surface of a hemisphere. Correlations were developed for expressing the effects of a number of dimensionless variables on the local and average Nusselt numbers. Results of the present study are compared with those from a similar study concerning a concave surface of a semicylindrical shell.

  17. Single Molecule Spectroelectrochemistry of Interfacial Charge Transfer Dynamics In Hybrid Organic Solar Cell

    SciTech Connect

    Pan, Shanlin

    2014-11-16

    Our research under support of this DOE grant is focused on applied and fundamental aspects of model organic solar cell systems. Major accomplishments are: 1) we developed a spectroelectorchemistry technique of single molecule single nanoparticle method to study charge transfer between conjugated polymers and semiconductor at the single molecule level. The fluorescence of individual fluorescent polymers at semiconductor surfaces was shown to exhibit blinking behavior compared to molecules on glass substrates. Single molecule fluorescence excitation anisotropy measurements showed the conformation of the polymer molecules did not differ appreciably between glass and semiconductor substrates. The similarities in molecular conformation suggest that the observed differences in blinking activity are due to charge transfer between fluorescent polymer and semiconductor, which provides additional pathways between states of high and low fluorescence quantum efficiency. Similar spectroelectrochemistry work has been done for small organic dyes for understand their charge transfer dynamics on various substrates and electrochemical environments; 2) We developed a method of transferring semiconductor nanoparticles (NPs) and graphene oxide (GO) nanosheets into organic solvent for a potential electron acceptor in bulk heterojunction organic solar cells which employed polymer semiconductor as the electron donor. Electron transfer from the polymer semiconductor to semiconductor and GO in solutions and thin films was established through fluorescence spectroscopy and electroluminescence measurements. Solar cells containing these materials were constructed and evaluated using transient absorption spectroscopy and dynamic fluorescence techniques to understand the charge carrier generation and recombination events; 3) We invented a spectroelectorchemistry technique using light scattering and electroluminescence for rapid size determination and studying electrochemistry of single NPs in an

  18. Distance dependence of the energy transfer rate from a single semiconductor nanostructure to graphene.

    PubMed

    Federspiel, François; Froehlicher, Guillaume; Nasilowski, Michel; Pedetti, Silvia; Mahmood, Ather; Doudin, Bernard; Park, Serin; Lee, Jeong-O; Halley, David; Dubertret, Benoît; Gilliot, Pierre; Berciaud, Stéphane

    2015-02-11

    The near-field Coulomb interaction between a nanoemitter and a graphene monolayer results in strong Förster-type resonant energy transfer and subsequent fluorescence quenching. Here, we investigate the distance dependence of the energy transfer rate from individual, (i) zero-dimensional CdSe/CdS nanocrystals and (ii) two-dimensional CdSe/CdS/ZnS nanoplatelets to a graphene monolayer. For increasing distances d, the energy transfer rate from individual nanocrystals to graphene decays as 1/d(4). In contrast, the distance dependence of the energy transfer rate from a two-dimensional nanoplatelet to graphene deviates from a simple power law but is well described by a theoretical model, which considers a thermal distribution of free excitons in a two-dimensional quantum well. Our results show that accurate distance measurements can be performed at the single particle level using graphene-based molecular rulers and that energy transfer allows probing dimensionality effects at the nanoscale.

  19. Activation of peroxisome proliferators-activated receptor δ (PPARδ) promotes blastocyst hatching in mice.

    PubMed

    Kang, Hee Jung; Hwang, Soo Jin; Yoon, Jung Ah; Jun, Jin Hyun; Lim, Hyunjung Jade; Yoon, Tae Ki; Song, Haengseok

    2011-10-01

    Prostaglandins participate in a variety of female reproductive processes, including ovulation, fertilization, embryo implantation and parturition. In particular, maternal prostacyclin (PGI(2)) is critical for embryo implantation and the action of PGI(2) is not mediated via its G-protein-coupled membrane receptor, IP, but its nuclear receptor, peroxisome-proliferator-activated receptor δ (PPARδ). Recently, several studies have shown that PGI(2) enhances blastocyst development and/or hatching rate in vitro, and subsequently implantation and live birth rates in mice. However, the mechanism by which PGI(2) improves preimplantation embryo development in vitro remains unclear. Using molecular, pharmacologic and genetic approaches, we show that PGI(2)-induced PPARδ activation accelerates blastocyst hatching in mice. mRNAs for PPARδ, retinoid X receptor (heterodimeric partners of PPARδ) and PGI(2) synthase (PGIS) are temporally induced after zygotic gene activation, and their expression reaches maximum levels at the blastocyst stage, suggesting that functional complex of PPARδ can be formed in the blastocyst. Carbaprostacyclin (a stable analogue of PGI(2)) and GW501516 (a PPARδ selective agonist) significantly accelerated blastocyst hatching but did not increase total cell number of cultured blastocysts. Whereas U51605 (a PGIS inhibitor) interfered with blastocyst hatching, GW501516 restored U51605-induced retarded hatching. In contrast to the improvement of blastocyst hatching by PPARδ agonists, PPAR antagonists significantly inhibited blastocyst hatching. Furthermore, deletion of PPARδ at early stages of preimplantation mouse embryos caused delay of blastocyst hatching, but did not impair blastocyst development. Taken together, PGI(2)-induced PPARδ activation accelerates blastocyst hatching in mice.

  20. Blastocyst development from supernumerary embryos after intracytoplasmic sperm injection: a paternal influence?

    PubMed

    Shoukir, Y; Chardonnens, D; Campana, A; Sakkas, D

    1998-06-01

    The success of intracytoplasmic sperm injection (ICSI) warrants further study on the role of paternal factors in early human embryogenesis. To investigate whether poor sperm parameters can influence embryo development, we examined the development of ICSI-fertilized embryos to the blastocyst stage. We present results of blastocyst development from supernumerary ICSI embryos after co-culture on monkey kidney epithelial cells. In addition, we compare the development of supernumerary embryos to the blastocyst stage after ICSI and in-vitro fertilization (IVF). Of 168 supernumerary ICSI embryos, 45 (26.8%) developed to blastocysts. Sperm concentration and morphology did not influence blastocyst development. In contrast, blastocysts arose from spermatozoa that had a significantly higher (P = 0.015) forward progressive motility compared with spermatozoa from those patients who failed to produce blastocysts (42.7% versus 28.2%, respectively). Overall the rate of embryo development to the blastocyst stage after ICSI was lower (26.8%) than that after IVF (47.3%). When the rate of blastocyst development was calculated for patients with three or more supernumerary embryos, it remained significantly higher for the IVF patients than for the ICSI patients (45.6% versus 30.0%). There was no significant difference in the mean cell number and quality of the supernumerary embryos between the IVF and ICSI patients. This study confirms previous reports that have postulated that abnormal spermatozoa may manifest a negative paternal effect on preimplantation embryo development.

  1. Single-crystal charge transfer interfaces for efficient photonic devices (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Alves, Helena; Pinto, Rui M.; Maçôas, Ermelinda M. S.; Baleizão, Carlos; Santos, Isabel C.

    2016-09-01

    Organic semiconductors have unique optical, mechanical and electronic properties that can be combined with customized chemical functionality. In the crystalline form, determinant features for electronic applications such as molecular purity, the charge mobility or the exciton diffusion length, reveal a superior performance when compared with materials in a more disordered form. Combining crystals of two different conjugated materials as even enable a new 2D electronic system. However, the use of organic single crystals in devices is still limited to a few applications, such as field-effect transistors. In 2013, we presented the first system composed of single-crystal charge transfer interfaces presenting photoconductivity behaviour. The system composed of rubrene and TCNQ has a responsivity reaching 1 A/W, corresponding to an external quantum efficiency of nearly 100%. A similar approach, with a hybrid structure of a PCBM film and rubrene single crystal also presents high responsivity and the possibility to extract excitons generated in acceptor materials. This strategy led to an extended action towards the near IR. By adequate material design and structural organisation of perylediimides, we demonstrate that is possible to improve exciton diffusion efficiency. More recently, we have successfully used the concept of charge transfer interfaces in phototransistors. These results open the possibility of using organic single-crystal interfaces in photonic applications.

  2. Biophysical Insights from Temperature-Dependent Single-Molecule Förster Resonance Energy Transfer.

    PubMed

    Holmstrom, Erik D; Nesbitt, David J

    2016-05-27

    Single-molecule fluorescence microscopy techniques can be used in combination with micrometer length-scale temperature control and Förster resonance energy transfer (FRET) in order to gain detailed information about fundamental biophysical phenomena. In particular, this combination of techniques has helped foster the development of remarkable quantitative tools for studying both time- and temperature-dependent structural kinetics of biopolymers. Over the past decade, multiple research efforts have successfully incorporated precise spatial and temporal control of temperature into single-molecule FRET (smFRET)-based experiments, which have uncovered critical thermodynamic information on a wide range of biological systems such as conformational dynamics of nucleic acids. This review provides an overview of various temperature-dependent smFRET approaches from our laboratory and others, highlighting efforts in which such methods have been successfully applied to studies of single-molecule nucleic acid folding.

  3. Biophysical Insights from Temperature-Dependent Single-Molecule Förster Resonance Energy Transfer

    NASA Astrophysics Data System (ADS)

    Holmstrom, Erik D.; Nesbitt, David J.

    2016-05-01

    Single-molecule fluorescence microscopy techniques can be used in combination with micrometer length-scale temperature control and Förster resonance energy transfer (FRET) in order to gain detailed information about fundamental biophysical phenomena. In particular, this combination of techniques has helped foster the development of remarkable quantitative tools for studying both time- and temperature-dependent structural kinetics of biopolymers. Over the past decade, multiple research efforts have successfully incorporated precise spatial and temporal control of temperature into single-molecule FRET (smFRET)-based experiments, which have uncovered critical thermodynamic information on a wide range of biological systems such as conformational dynamics of nucleic acids. This review provides an overview of various temperature-dependent smFRET approaches from our laboratory and others, highlighting efforts in which such methods have been successfully applied to studies of single-molecule nucleic acid folding.

  4. Planar embryos have poor prognosis in terms of blastocyst formation and implantation.

    PubMed

    Ebner, T; Maurer, M; Shebl, O; Moser, M; Mayer, R B; Duba, H C; Tews, G

    2012-09-01

    Normally, day-2 embryos show a crosswise arrangement of four cells with three blastomeres lying side by side. Cleavage anomalies include embryos that are characterized by a particular planar constellation of four blastomeres with presumed incomplete cleavage. Since little is known on the developmental fate of such conceptuses, within a 10-month period all consecutive patients were screened for day-2 planar embryos. A total of 64/2070 embryos with suboptimal blastomere configuration were detected (3.1%). In conventional IVF, planar embryos were significantly less frequent (0.7%) as compared with intracytoplasmic sperm injection (2.8%; P<0.05) and cases of testicular sperm extraction (5.4%; P<0.01). Interestingly, embryos with a cleavage anomaly showed better morphology both on day 2 (P<0.005) and day 3 (P<0.001). In contrast, blastocyst formation (P<0.001) and blastocyst quality (P=NS) was higher in tetrahedral embryos. There was a significant increase in implantation rate if tetrahedral embryos could be transferred compared with when planar embryos had to be transferred (P<0.01). It may be postulated that, in planar embryos, the mitotic spindle might have been affected, e.g. sperm centrosome composition or function, which in turn might have led to the observed cleavage anomaly. Normally, day-2 embryos show a crosswise arrangement of four cells with three blastomeres lying side by side. Cleavage anomalies include more planar embryos that are characterized by a particular flat constellation of four blastomeres with presumed premature cleavage (like a tetrafoliate clover). Since little is known on the developmental fate of such embryos within a 10-month study period, all consecutive patients were screened for the presence of day-2 planar embryos (study group). A total of 64 (out of 2070) embryos with abnormal blastomere configuration were detected (3.1%). Interestingly, in conventional IVF (0.7%), the presence of planar embryos was significantly less frequent as

  5. Blastocyst viability and generation of transgenic cattle following freezing of in vitro produced, DNA-injected embryos.

    PubMed

    Han, Y M; Kim, S J; Park, J S; Park, I Y; Kang, Y K; Lee, C S; Koo, D B; Lee, T H; Yu, D Y; Kim, Y H; Lee, K J; Lee, K K

    2000-10-02

    This study examined whether the viability, determined in vitro, of DNA-injected bovine embryos produced in vitro was affected by freezing, and if the frozen embryos developed to term following transfer to recipients. In vitro fertilized zygotes were injected with the pBL1 gene and then co-cultured with mouse embryonic fibroblasts (MEF) in CR1aa medium. Embryos were prepared for cryopreservation by exposure to a 10% (v/v) glycerol solution, loaded into 0.25 ml straws and then frozen by conventional slow freezing. Thawing was by rapid warming in water (37 degrees C) and embryos were rehydrated in PBS diluents of 6%, 3% and 0% (v/v) glycerol supplemented with 0.25 M sucrose and 0.5% (w/v) BSA. In Experiment 1, blastocysts that developed from DNA-injected embryos were individually classified into three morphological groups and three stages of development prior to freezing. DNA-injected blastocysts of excellent quality at freezing showed a higher survival rate (78.8+/-10.6%) after thawing than those of good (60. 9+/-16.4%) or fair (12.5+/-5.9%) quality (P<0.05). Post-thaw survival rate, judged in vitro, increased with more advanced stage of blastocyst development at freezing (early 48.8+/-15.9%, mid 52. 1+/-12.6% and expanded 71.2+/-1.1; P<0.05). In Experiment 2, the frozen/thawed embryos were transferred to recipients to examine in vivo viability. Following transfer of one or two embryos per recipient, pregnancy rates at 60 days of gestation were 13.6% (13/96) for frozen embryos and 26.5% (43/162) for fresh embryos (P<0. 05). Of the 12 live calves born from the frozen/thawed embryos, two males (18.3%) were transgenic. None of the live-born calves derived from fresh embryos exhibited the transgene. One of transgenic bulls did not produce transgenic sperm. Three out of 23 calves (13.0%) produced from cows inseminated with semen of the other bull were transgenic, suggesting that this animal was a germ-line mosaic. These studies indicated that the viability of in vitro

  6. Non-invasive prediction of blastocyst implantation, ongoing pregnancy and live birth, by mass spectrometry lipid fingerprinting

    PubMed Central

    Borges Jr., Edson; Braga, Daniela P.A.F.; Setti, Amanda Souza; Montanni, Daniela A.; Cabral, Elaine Cristina; Eberlin, Marcos N.; Turco, Edson G. Lo; Iaconelli Jr, Assumpto

    2016-01-01

    Objective To identify lipid markers of blastocyst implantation and ongoing pregnancy by day three culture medium mass spectrometry (MS) fingerprinting. Methods For this study, 33 culture media samples were harvested on day three, from 22 patients undergoing day five embryo transfers. All embryos achieved the blastocyst stage and were split into groups based on their implantation (Negative Implantation, n= 14 and Positive Implantation, n= 19). The positive implantation cycles resulted in successful ongoing pregnancies. The lipid extraction was performed by the Bligh-Dyer protocol and mass spectra were obtained with a direct infusion into a Q-Tof mass spectrometer. The data obtained was analyzed by Principal Component Analysis (PCA) and Partial Least Square Discrimination Analysis (PLS-DA). The statistical analysis was performed using the Metabo-Analyst 2.0. Results The variable importance in the projection (VIP) plot of the PLS-DA provided a list of four ions, in the positive mode, with an area under the curve (AUC) of 73.5%; and eight ions, in the negative mode, with and AUC of 72.0%. For both positive and negative modes, possible biomarkers for the negative implantation were identified by the lipidmaps: phosphoethanolamine, dicarboxylic acids, glycerophosphoglycerol, glycerophosphocholine, glicerophosphoinositol, phosphoethanolamine and unsaturated fat acids. The other ions were not identified. These lipids are involved in the GPI anchor biosynthesis and synthesis of lycerophospholipids and phosphate inositol. Conclusion MS fingerprinting is useful to identify blastocysts that fail to implant, and therefore this technique could be incorporated into the laboratory routine, adjunct to morphology evaluation to identify embryos that should not be transferred. PMID:28050958

  7. Rapid policy change to single-embryo transfer while maintaining pregnancy rates per initiated cycle.

    PubMed

    Vélez, M P; Kadoch, I-J; Phillips, S J; Bissonnette, F

    2013-05-01

    Public financing of IVF aims at increasing access to treatment while decreasing the expenses associated with multiple pregnancies. Critics argue that it is associated with lower pregnancy rates. This study compared cycles performed during 2009 (before implementation of Quebec's public IVF programme; period I) to those performed in the year following implementation (period II) in a single IVF centre. First fresh cycles in period I (499 women) and first fresh cycles (815 women) along with their corresponding first vitrified-warmed transfer (271 women) in period II were evaluated. From period I to period II, single-embryo transfer increased from 17.3% to 85.0% (P<0.001), multiple ongoing pregnancy rate decreased from 25.8% to 1.6% (P<0.001) and ongoing pregnancy rate decreased from 31.9% to 23.3% (P=0.001). During period II, the ongoing pregnancy rate per vitrified-warmed embryo transfer was 19.2%, leading to a cumulative ongoing pregnancy rate per initiated cycle of 29.7%, which was not different to the pregnancy rate per fresh cycle during period I (31.9%). To conclude, Quebec's public IVF programme decreased multiple pregnancy rates while maintaining an acceptable cumulative ongoing pregnancy rate, a more precise outcome to evaluate the impact of public IVF programmes.

  8. Local heat transfer coefficients under an axisymmetric, single-phase liquid jet

    SciTech Connect

    Stevens, J.; Webb, B.W. )

    1991-02-01

    The purpose of this investigation was to characterize local heat transfer coefficients for round, single-phase free liquid jets impinging normally against a flat uniform heat flux surface. The problems parameters investigated were jet Reynolds number Re, nozzle-to-plate spacing z, and jet diameter d. A region of near-constant Nusselt number was observed for the region bounded by 0 {le} r/d {le} 0.75, where is the radical distance from the impingement point. The local Nusselt number profiles exhibited a sharp drop for r/d > 0.75, followed by an inflection and a shower decrease thereafter. Increasing the nozzle-to-plate spacing generally decreased the heat transfer slightly. The local Nusselt number characteristics were found to be dependent on nozzle diameter. This was explained by the influence of the free-stream velocity gradient on local heat transfer, as predicted in the classical analysis of infinite jet stagnation flow and heat transfer. Correlations for local and average Nusselt numbers reveal an approximate Nusselt number dependence on Re{sup 1,3}.

  9. Comprehensive cross production system assessment of the impact of in vitro microenvironment on the expression of messengers and long non-coding RNAs in the bovine blastocyst.

    PubMed

    Côté, Isabelle; Vigneault, Christian; Laflamme, Isabelle; Laquerre, Joanie; Fournier, Éric; Gilbert, Isabelle; Scantland, Sara; Gagné, Dominic; Blondin, Patrick; Robert, Claude

    2011-07-01

    In vitro production (IVP) of cattle embryos over the past two decades has revealed several negative impacts that have been attributed to the artificial microenvironment. Studies on embryos produced in vitro clearly point to aberrant gene expression levels. So far, the causal association between phenotype and measured gene expression has not led to substantial improvement of IVP systems. The aim of this study was to generate a unique dataset composed of microarray-derived relative transcript abundance values for blastocysts produced in ten in vitro systems differing primarily in culture medium formulation. Between-group comparisons determine the level of overall similarity among systems relative to in vivo reference embryos. The use of the dataset to contrast all in vitro treatments with the in vivo blastocysts pointed to a single common gene network. The 'boutique' array contained a panel of novel uncharacterized transcripts that were variably expressed depending on the medium in which the blastocysts were produced. These novel transcripts were differentially expressed in blastocysts even as carryover from conditions encountered 7 days earlier during oocyte maturation. All of the selected novel candidates thus expressed were from intergenic regions. The function of this long non-coding RNA remains unknown but clearly points to an additional level of complexity in early embryo development.

  10. Distinct differences in global gene expression profiles in non-implanted blastocysts and blastocysts resulting in live birth.

    PubMed

    Kirkegaard, Kirstine; Villesen, Palle; Jensen, Jacob Malte; Hindkjær, Johnny Juhl; Kølvraa, Steen; Ingerslev, Hans Jakob; Lykke-Hartmann, Karin

    2015-10-25

    Results from animal models points towards the existence of a gene expression profile that is distinguishably different in viable embryos compared with non-viable embryos. Knowledge of human embryo transcripts is however limited, in particular with regard to how gene expression is related to clinical outcome. The purpose of the present study was therefore to determine the global gene expression profiles of human blastocysts. Next Generation Sequencing was used to identify genes that were differentially expressed in non-implanted embryos and embryos resulting in live birth. Three trophectoderm biopsies were obtained from morphologically high quality blastocysts resulting in live birth and three biopsies were obtained from non-implanting blastocysts of a comparable morphology. Total RNA was extracted from all samples followed by complete transcriptome sequencing. Using a set of filtering criteria, we obtained a list of 181 genes that were differentially expressed between trophectoderm biopsies from embryos resulting in either live birth or no implantation (negative hCG), respectively. We found that 37 of the 181 genes displayed significantly differential expression (p<0.05), e.g. EFNB1, CYTL1 and TEX26 and TESK1, MSL1 and EVI5 in trophectoderm biopsies associated with live birth and non-implanting, respectively. Out of the 181 genes, almost 80% (145 genes) were up-regulated in biopsies from un-implanted embryos, whereas only 20% (36 genes) showed an up-regulation in the samples from embryos resulting in live birth. Our findings suggest the presence of molecular differences visually undetectable between implanted and non-implanted embryos, and represent a proof of principle study.

  11. 88 EFFECT OF BICARBONATE/CO2 LEVEL DURING EMBRYO CULTURE ON EQUINE BLASTOCYST RATE AFTER INTRACYTOPLASMIC SPERM INJECTION.

    PubMed

    Choi, Y H; Tinetti, P; Brom-de-Luna, J G; Hinrichs, K

    2016-01-01

    Equine embryos appear to require a high glucose concentration for development to the blastocyst stage. The complete cell-culture medium, DMEM/F-12 (DM), which contains 17mM glucose, has been widely used for equine embryo culture; however, in other species, high glucose during the early stages of embryo development is detrimental. To avoid this, we initiated a 2-step system using a low-glucose human embryo culture medium (Global) from Days 0 to 5 [Day 0=day of intracytoplasmic sperm injection (ICSI)], with glucose (20mM) added to the medium in the second step (Days 5 to 10; Choi et al. 2015 Reproduction 150, 31-41). We noted a high pregnancy loss rate (20%) in our clinical ICSI program (Hinrichs et al. 2014 J. Equine Vet. Sci. 34, 176), which used this 2-step Global system. Limited data are available on pregnancy with DM-produced embryos, but in one study, the loss rate was 1/13 (7.7%; Choi et al. 2011 Reproduction 142, 529-538). It is possible that use of DM in the second step of culture would better support normal blastocyst development than does Global with added glucose. However, DM is typically used at 5% CO2, and Global at 6% CO2, so use of both media would necessitate 2 sets of incubators. In the present study, we explored the use of DM in the second step of a two-step equine embryo culture system, under different CO2 environments. Oocytes were collected from research mares via follicle aspiration and were held overnight before being matured in vitro for 30h. All media included 10% fetal bovine serum. On Days 0 to 5 after ICSI, all embryos were cultured in Global under 6% CO2 in mixed gas (5% O2 and remainder N2) at 38.2°C. In Experiment 1, on Day 5, embryos were transferred to DM prepared according to our standard method, with 14.3mM NaHCO3 and 5mM NaOH, and were cultured in mixed gas at either 5% CO2 or 6% CO2. Five replicates were performed. In Experiment 2, DM was prepared by our standard method, or with 24.2mM bicarbonate and no NaOH. When pH was

  12. High-fidelity transfer and storage of photon states in a single nuclear spin

    NASA Astrophysics Data System (ADS)

    Yang, Sen; Wang, Ya; Rao, D. D. Bhaktavatsala; Hien Tran, Thai; Momenzadeh, Ali S.; Markham, M.; Twitchen, D. J.; Wang, Ping; Yang, Wen; Stöhr, Rainer; Neumann, Philipp; Kosaka, Hideo; Wrachtrup, Jörg

    2016-08-01

    Long-distance quantum communication requires photons and quantum nodes that comprise qubits for interaction with light and good memory capabilities, as well as processing qubits for the storage and manipulation of photons. Owing to the unavoidable photon losses, robust quantum communication over lossy transmission channels requires quantum repeater networks. A necessary and highly demanding prerequisite for these networks is the existence of quantum memories with long coherence times to reliably store the incident photon states. Here we demonstrate the high-fidelity (˜98%) coherent transfer of a photon polarization state to a single solid-state nuclear spin that has a coherence time of over 10 s. The storage process is achieved by coherently transferring the polarization state of a photon to an entangled electron-nuclear spin state of a nitrogen-vacancy centre in diamond. The nuclear spin-based optical quantum memory demonstrated here paves the way towards an absorption-based quantum repeater network.

  13. Single molecule studies of a ladder type conjugated polymer: vibronic spectra, line widths, and energy transfer.

    PubMed

    Zickler, Martin F; Feist, Florian A; Jacob, Josemon; Müllen, Klaus; Basché, Thomas

    2015-06-01

    Confocal fluorescence microscopy and spectroscopy are employed to investigate single poly(ladder-type pentaphenylene) (LPPentP) molecules dispersed in thin poly(methyl methacrylate) (PMMA) films at 1.2 K. Emission spectra of single chains show single as well as multi-chromophore emission indicating variegated communication along the chains. The vibronic structure in the emission spectra resembles the one found for other ladder-type polymers. Purely electronic zero-phonon lines in emission are substantially broadened, most probably due to fast spectral diffusion. By surmounting the limitations of emission spectroscopy, nonemitting donor chromophores, which transfer their excitation energy in a radiationless manner to emitting chromophores, are accessed by excitation spectroscopy. Remarkably, by comparing the data of emitting and nonemitting chromophores a contribution to the zero-phonon excitation line width has to be considered which places a lower limit on the estimated energy transfer time of several picoseconds between adjacent chromophores. Finally, the data indicate qualitatively a restricted flexibility of LPPentP compared to poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV).

  14. Single-stage reconstruction of flexor tendons with vascularized tendon transfers.

    PubMed

    Cavadas, P C; Pérez-García, A; Thione, A; Lorca-García, C

    2015-03-01

    The reconstruction of finger flexor tendons with vascularized flexor digitorum superficialis (FDS) tendon grafts (flaps) based on the ulnar vessels as a single stage is not a popular technique. We reviewed 40 flexor tendon reconstructions (four flexor pollicis longus and 36 finger flexors) with vascularized FDS tendon grafts in 38 consecutive patients. The donor tendons were transferred based on the ulnar vessels as a single-stage procedure (37 pedicled flaps, three free flaps). Four patients required composite tendon and skin island transfer. Minimum follow-up was 12 months, and functional results were evaluated using a total active range of motion score. Multiple linear regression analysis was performed to evaluate the factors that could be associated with the postoperative total active range of motion. The average postoperative total active range of motion (excluding the thumbs) was 178.05° (SD 50°). The total active range of motion was significantly lower for patients who were reconstructed with free flaps and for those who required composite tendon and skin island flap. Age, right or left hand, donor/motor tendon and pulley reconstruction had no linear effect on total active range of motion. Overall results were comparable with a published series on staged tendon grafting but with a lower complication rate. Vascularized pedicled tendon grafts/flaps are useful in the reconstruction of defects of finger flexor tendons in a single stage, although its role in the reconstructive armamentarium remains to be clearly established.

  15. X chromosome regulation of autosomal gene expression in bovine blastocysts.

    PubMed

    Itoh, Yuichiro; Arnold, Arthur P

    2014-10-01

    Although X chromosome inactivation in female mammals evolved to balance the expression of X chromosome and autosomal genes in the two sexes, female embryos pass through developmental stages in which both X chromosomes are active in somatic cells. Bovine blastocysts show higher expression of many X genes in XX than XY embryos, suggesting that X inactivation is not complete. Here, we reanalyzed bovine blastocyst microarray expression data from a network perspective with a focus on interactions between X chromosome and autosomal genes. Whereas male-to-female ratios of expression of autosomal genes were distributed around a mean of 1, X chromosome genes were clearly shifted towards higher expression in females. We generated gene coexpression networks and identified a major module of genes with correlated gene expression that includes female-biased X genes and sexually dimorphic autosomal genes for which the sexual dimorphism is likely driven by the X genes. In this module, expression of X chromosome genes correlates with autosome genes, more than the expression of autosomal genes with each other. Our study identifies correlated patterns of autosomal and X-linked genes that are likely influenced by the sexual imbalance of X gene expression when X inactivation is inefficient.

  16. Telomere lengths in human oocytes, cleavage stage embryos and blastocysts

    PubMed Central

    Turner, S.; Wong, H.P.; Rai, J.; Hartshorne, G.M.

    2010-01-01

    Telomeres are repeated sequences that protect the ends of chromosomes and harbour DNA repair proteins. Telomeres shorten during each cell division in the absence of telomerase. When telomere length becomes critically short, cell senescence occurs. Telomere length therefore reflects both cellular ageing and capacity for division. We have measured telomere length in human germinal vesicle (GV) oocytes and preimplantation embryos, by quantitative fluorescence in situ hybridization (Q-FISH), providing baseline data towards our hypothesis that telomere length is a marker of embryo quality. The numbers of fluorescent foci suggest that extensive clustering of telomeres occurs in mature GV stage oocytes, and in preimplantation embryos. When calculating average telomere length by assuming that each signal presents one telomere, the calculated telomere length decreased from the oocyte to the cleavage stages, and increased between the cleavage stages and the blastocyst (11.12 versus 8.43 versus 12.22 kb, respectively, P < 0.001). Other methods of calculation, based upon expected maximum and minimum numbers of telomeres, confirm that telomere length in blastocysts is significantly longer than cleavage stages. Individual blastomeres within an embryo showed substantial variation in calculated average telomere length. This study implies that telomere length changes according to the stage of preimplantation embryo development. PMID:20573647

  17. Embryo Aggregation Promotes Derivation Efficiency of Outgrowths from Porcine Blastocysts

    PubMed Central

    Lee, Sang-Goo; Park, Jin-Kyu; Choi, Kwang-Hwan; Son, Hye-Young; Lee, Chang-Kyu

    2015-01-01

    Porcine embryonic stem cells (pESCs) have become an advantageous experimental tool for developing therapeutic applications and producing transgenic animals. However, despite numerous reports of putative pESC lines, deriving validated pESC lines from embryos produced in vitro remains difficult. Here, we report that embryo aggregation was useful for deriving pESCs from in vitro-produced embryos. Blastocysts derived from embryo aggregation formed a larger number of colonies and maintained cell culture stability. Our derived cell lines demonstrated expression of pluripotent markers (alkaline phosphatase, Oct4, Sox2, and Nanog), an ability to form embryoid bodies, and the capacity to differentiate into the three germ layers. A cytogenetic analysis of these cells revealed that all lines derived from aggregated blastocysts had normal female and male karyotypes. These results demonstrate that embryo aggregation could be a useful technique to improve the efficiency of deriving ESCs from in vitro-fertilized pig embryos, studying early development, and deriving pluripotent ESCs in vitro in other mammals. PMID:26580280

  18. Human Endometrial CD98 Is Essential for Blastocyst Adhesion

    PubMed Central

    Domínguez, Francisco; Simón, Carlos; Quiñonero, Alicia; Ramírez, Miguel Ángel; González-Muñoz, Elena; Burghardt, Hans; Cervero, Ana; Martínez, Sebastián; Pellicer, Antonio; Palacín, Manuel; Sánchez-Madrid, Francisco; Yáñez-Mó, María

    2010-01-01

    Background Understanding the molecular basis of embryonic implantation is of great clinical and biological relevance. Little is currently known about the adhesion receptors that determine endometrial receptivity for embryonic implantation in humans. Methods and Principal Findings Using two human endometrial cell lines characterized by low and high receptivity, we identified the membrane receptor CD98 as a novel molecule selectively and significantly associated with the receptive phenotype. In human endometrial samples, CD98 was the only molecule studied whose expression was restricted to the implantation window in human endometrial tissue. CD98 expression was restricted to the apical surface and included in tetraspanin-enriched microdomains of primary endometrial epithelial cells, as demonstrated by the biochemical association between CD98 and tetraspanin CD9. CD98 expression was induced in vitro by treatment of primary endometrial epithelial cells with human chorionic gonadotropin, 17-β-estradiol, LIF or EGF. Endometrial overexpression of CD98 or tetraspanin CD9 greatly enhanced mouse blastocyst adhesion, while their siRNA-mediated depletion reduced the blastocyst adhesion rate. Conclusions These results indicate that CD98, a component of tetraspanin-enriched microdomains, appears to be an important determinant of human endometrial receptivity during the implantation window. PMID:20976164

  19. Comparative aspects of blastocyst-endometrial interactions at implantation.

    PubMed

    Enders, A C; Schlafke, S

    1978-01-01

    Since the trophoblast-uterine adhesion is as nearly a universal phenomenon in implantation as can be found, an attempt was made to determine whether or not there was a reduction in cell surface glycoproteins in the rat, as can be observed in the ferret. Neither colloidal iron nor cationized ferritin revealed the type of pattern anticipated for a localized reduction in surface negativity in the imprint of the blastocyst in the implantation chamber. The use of lectin-coated latex beads also proved disappointing in defining regional differences in adhesiveness. However, a number of observations on the changing shape of the implantation chamber, the secretion of periluminal material by decidual cells, and the penetration of the residual basal lamina of the luminal epithelium by the decidual cells were made in the course of these studies. The implantation chamber of the rabbit, in which the blastocyst does not make an imprint, was contrasted with that of the rat. The areas of fusion of trophoblast knobs with uterin epithelial cells shown to be visible by scanning electron microscopy. Finally, some observations on the hypertrophy of maternal epithelial cells to form the uterine plaque in the rhesus monkey are described, and the hypertrophy of endothelial cells to form admirably suited to protein secretion is presented.

  20. Single-molecule interfacial electron transfer dynamics in solar energy conversion

    NASA Astrophysics Data System (ADS)

    Dhital, Bharat

    This dissertation work investigated the parameters affecting the interfacial electron transfer (ET) dynamics in dye-semiconductor nanoparticles (NPs) system by using single-molecule fluorescence spectroscopy and imaging combined with electrochemistry. The influence of the molecule-substrate electronic coupling, the molecular structure, binding geometry on the surface and the molecule-attachment surface chemistry on interfacial charge transfer processes was studied on zinc porphyrin-TiO2 NP systems. The fluorescence blinking measurement on TiO2 NP demonstrated that electronic coupling regulates dynamics of charge transfer processes at the interface depending on the conformation of molecule on the surface. Moreover, semiconductor surface charge induced electronic coupling of molecule which is electrostatically adsorbed on the semiconductor surface also predominantly alters the ET dynamics. Furthermore, interfacial electric field and electron accepting state density dependent ET dynamics has been dissected in zinc porphyrin-TiO2 NP system by observing the single-molecule fluorescence blinking dynamics and fluorescence lifetime with and without applied bias. The significant difference in fluorescence fluctuation and lifetime suggested the modulation of charge transfer dynamics at the interface with external electric field perturbation. Quasi-continuous distribution of fluorescence intensity with applied negative potential was attributed to the faster charge recombination due to reduced density of electron accepting states. The driving force and electron accepting state density ET dependent dynamics has also been probed in zinc porphyrin-TiO2 NP and zinc porphyrin-indium tin oxide (ITO) systems. Study of a molecule adsorbed on two different semiconductors (ITO and TiO2), with large difference in electron densities and distinct driving forces, allows us to observe the changes in rates of back electron transfer process reflected by the suppressed fluorescence blinking of

  1. Single scattering solution for radiative transfer through Rayleigh and aerosol atmosphere

    NASA Technical Reports Server (NTRS)

    Otterman, J.

    1977-01-01

    A solution is presented to the radiative transfer of the solar irradiation through a turbid atmosphere, based on the single-scattering approximation, i.e., an assumption that a photon that underwent scattering either leaves the top of the atmosphere or strikes the surface. The solution depends on a special idealization of the scattering phase function of the aerosols. The equations developed are subsequently applied to analyze quantitatively the enhancement of the surface irradiation and the enhancement of the scattered radiant emittance as seen from above the atmosphere, caused by the surface reflectance and atmospheric back scattering. An order of magnitude error analysis is presented.

  2. COBRA-SFS predictions of single assembly spent fuel heat transfer data

    SciTech Connect

    Lombardo, N.J.; Michener, T.E.; Wheeler, C.L.; Rector, D.R.

    1986-04-01

    The study reported here is one of several efforts to evaluate and qualify the COBRA-SFS computer code for use in spent fuel storage system thermal analysis. The ability of COBRA-SFS to predict the thermal response of two single assembly spent fuel heat transfer tests was investigated through comparisons of predictions with experimental test data. From these comparisons, conclusions regarding the computational treatment of the physical phenomena occurring within a storage system can be made. This objective was successfully accomplished as reasonable agreement between predictions and data were obtained for the 21 individual test cases of the two experiments.

  3. On the charge transfer between single-walled carbon nanotubes and graphene

    SciTech Connect

    Rao, Rahul Pierce, Neal; Dasgupta, Archi

    2014-08-18

    It is important to understand the electronic interaction between single-walled carbon nanotubes (SWNTs) and graphene in order to use them efficiently in multifunctional hybrid devices. Here, we deposited SWNT bundles on graphene-covered copper and SiO{sub 2} substrates by chemical vapor deposition and investigated the charge transfer between them by Raman spectroscopy. Our results revealed that, on both copper and SiO{sub 2} substrates, graphene donates electrons to the SWNTs, resulting in p-type doped graphene and n-type doped SWNTs.

  4. Uterine micro-environment and estrogen-dependent regulation of osteopontin expression in mouse blastocyst.

    PubMed

    Xie, Qing-Zhen; Qi, Qian-Rong; Chen, Ying-Xian; Xu, Wang-Ming; Liu, Qian; Yang, Jing

    2013-07-11

    Embryo implantation is a highly synchronized bioprocess between an activated blastocyst and a receptive uterus. In mice, successful implantation relies on the dynamic interplay of estrogen and progesterone; however, the key mediators downstream of these hormones that act on blastocyst competency and endometrium receptivity acquisition are largely unknown. In this study, we showed that the expression of osteopontin (OPN) in mouse blastocysts is regulated by ovarian estrogen and uterine micro-environment. OPN mRNA is up-regulated in mouse blastocyst on day 4 of pregnancy, which is associated with ovarian estrogen secretion peak. Hormone treatment in vivo demonstrated that OPN expression in a blastocyst is regulated by estrogen through an estrogen receptor (ER). Our results of the delayed and activated implantation model showed that OPN expression is induced after estrogen injection. While estrogen treatment during embryo culture in vitro showed less effect on OPN expression, the tubal ligation model on day 3 of pregnancy confirmed that the regulation of estrogen on OPN expression in blastocyst might, through some specific cytokines, have existed in a uterine micro-environment. Collectively, our study presents that estrogen regulates OPN expression and it may play an important role during embryo implantation by activating blastocyst competence and facilitating the endometrium acceptable for active blastocyst.

  5. Effects of acetyl-L-carnitine on lamb oocyte blastocyst rate, ultrastructure, and mitochondrial DNA copy number.

    PubMed

    Reader, Karen L; Cox, Neil R; Stanton, Jo-Ann L; Juengel, Jennifer L

    2015-06-01

    Viable lambs can be produced after transfer of in vitro-derived embryos from oocytes harvested from prepubertal lambs. However, this occurs at a much lower efficiency than from adult ewe oocyte donors. The reduced competence of prepubertal oocytes is believed to be due, at least in part, to deficiencies in cytoplasmic maturation. Differences in the cytoplasmic ultrastructure between prepubertal and adult oocytes have been described in the sheep, pig, and cow. Prepubertal lamb oocytes have been shown to have a different distribution of mitochondria and lipid droplets, and less mitochondria and storage vesicles than their adult counterparts. L-carnitine plays a role in supplying energy to the cell by transporting long-chain fatty acids into mitochondria for β-oxidation to produce ATP. Both L-carnitine and its derivative acetyl-L-carnitine have been reported to increase the blastocyst rate of oocytes from mice, cows, and pigs, treated during IVM. L-carnitine has also been shown to increase mitochondrial biogenesis in adipose cells. Therefore, the aims of this study were to determine if treatment of oocytes from prepubertal lambs with acetyl-L-carnitine during IVM could increase the blastocyst rate and alter mitochondria, vesicle, or lipid droplet number, volume, or distribution. The blastocyst rate was doubled in prepubertal lamb oocytes treated with acetyl-L-carnitine when compared to untreated oocytes (10.0% and 4.6%, respectively; P = 0.028). Light microscopy, scanning electron microscopy, and stereology techniques were used to quantify organelles in untreated and acetyl-L-carnitine-treated lamb oocytes, and quantitative polymerase chain reaction methods were used to measure the mitochondrial DNA copy number. There were no differences in mitochondrial volume, number, or mitochondrial DNA copy number. Acetyl-L-carnitine treatment increased the cytoplasmic volume (P = 0.015) of the oocytes, and there were trends toward an increase in the vesicle volume (P = 0

  6. Enantioselective N-Heterocyclic Carbene-Catalyzed β-Hydroxylation of Enals Using Nitroarenes: An Atom Transfer Reaction That Proceeds via Single Electron Transfer

    PubMed Central

    2015-01-01

    A novel oxidative N-heterocyclic carbene-catalyzed reaction pathway has been discovered. Alkyl and aryl enals undergo β-hydroxylation via oxygen atom transfer from electron-deficient nitrobenzenes, followed by trapping of the resultant acyl azolium by the solvent. The proposed mechanism involves a single electron transfer event to initiate the reaction followed by radical recombination. This represents a profound mechanistic departure from the established two-electron disconnects in NHC catalysis. PMID:25302860

  7. Microcell-mediated transfer of a single human chromosome complements xeroderma pigmentosum group A fibroblasts

    SciTech Connect

    Schultz, R.A.; Saxon, P.J.; Glover, T.W.; Friedberg, E.C.

    1987-06-01

    Chromosomes from an immortalized aneuploid human fibroblast cell line were randomly tagged with the selectable marker neo by transfection with the plasmid pSV2neo. Somatic cell fusions between transfected human cells and mouse A9 cells generated pools of G418-resistant human-mouse hybrid clones containing various numbers of human chromosomes. Microcell-mediated chromosome transfer from the hybrid pools to xeroderma pigmentosum complementation group A (XP-A) cells in culture and selection for G418-resistant colonies resulted in the identification of XP cells with enhanced resistance to ultraviolet radiation. Screening of subclones from selected pools of human-mouse hybrids facilitated the identification of hybrids containing a single neo-tagged human chromosome. Transfer of this chromosome to XP-A cells (but not to XP-F or XP-C cells) results in enhanced resistance to ultraviolet light and enhanced excision repair capacity. The identification of a single human chromosome that complements the phenotype of XP-A cells in culture provides the potential for genetic mapping of the complementing gene and for its isolation by molecular cloning.

  8. Expression and function of cyclooxygenase-2 is necessary for hamster blastocyst hatching.

    PubMed

    Sen Roy, Shubhendu; Seshagiri, Polani B

    2013-12-01

    Blastocyst hatching is critical for successful implantation leading to pregnancy. Its failure causes infertility. The phenomenon of blastocyst hatching in humans is poorly understood and the available information on this stems from studies of rodents such as mice and hamsters. We and others showed that hamster blastocyst hatching is characterized by firstly blastocyst deflation followed by a dissolution of the zona pellucida (zona) and accompanied by trophectodermal projections (TEPs). We also showed that embryo-derived cathepsins (Cat) proteases, specifically Cat-L, -B and -P act as zonalysins and are responsible for hatching. In this study, we show the expression and function of one of the potential regulators of embryogenesis, cyclooxygenase (COX)-2 during blastocyst development and hatching. The expression of COX-2 mRNA and protein was observed in 8-cell through hatched blastocyst stages and it was also localized to blastocyst's TEPs. Specific COX-2 inhibitors, NS-398 and CAY-10404, inhibited blastocyst hatching; percentages achieved were only 28.4 ± 5.3 and 32.3 ± 5.4%, respectively, compared with >90% with untreated embryos. Interestingly, inhibitor-treated blastocysts failed to deflate, normally observed during hatching. Supplementation of prostaglandins (PGs)-E2 or -I2 to cultured embryos reversed the inhibitors' effect on hatching and also the deflation behavior. Importantly, the levels of mRNA and protein of Cat-L, -B and -P showed a significant reduction in the inhibitor-treated embryos compared with untreated embryos, although its mechanism remains to be examined. These data provide the first evidence that COX-2 is critical for blastocyst hatching in the golden hamster.

  9. Expression of HSG is essential for mouse blastocyst formation

    SciTech Connect

    Jiang Guangjian; Pan Lei; Huang Xiuying; Han Mei; Wen Jinkun . E-mail: wjk@hebmu.edu.cn; Sun Fangzhen . E-mail: fzsun@genetics.ac.cn

    2005-09-23

    It has been shown recently that hyperplasia suppressor gene (HSG) is a powerful regulator for cell proliferation and has a critical role in mitochondrial fusion in many cells. However, little is known about its expression, localization, and function during oocyte maturation and early embryogenesis. In this study, with indirect immunofluorescent staining and Western blotting, we found that HSG was expressed in mouse oocytes and preimplantation embryos which primarily exhibited a submembrane distribution pattern in the cytoplasm. Moreover, HSG mainly associated with {beta}-tubulin during oocyte maturation and early embryonic development. When mouse zygotes were injected with HSG antisense plasmid and cultured in vitro, their capacity to form blastocysts was severely impaired. Our results indicate that HSG plays an essential role in mouse preimplantation development.

  10. Derivation of embryonic stem cells from Brown Norway rats blastocysts.

    PubMed

    Zhao, Xiaoyang; Lv, Zhuo; Liu, Lei; Wang, Liu; Tong, Man; Zhou, Qi

    2010-07-01

    Knockout Brown Norway (BN) rat could be a useful disease model for human disorders, however, a failure to derive embryonic stem (ES) cells disturbs the further development of the model. In this study, we reported a case of successful derivation of the BN rat ES cells with the derivation efficiency comparable to that of Sprague Dawley (SD) rats. The BN rat ES cells expressed the key transcription factors, and were able to form embryonic bodies (EBs) when being differentiated in vitro. After injecting the BN rat ES cells into the SD rat blastocysts, high-contribution chimeric rats were generated and could survive to their adulthood. Our success in generating pluripotent rat ES cells will benefit the generation of the knockout rats in the future.

  11. Elective single-embryo transfer: persuasive communication strategies can affect choice in a young British population.

    PubMed

    van den Akker, O B A; Purewal, S

    2011-12-01

    This study tested the effectiveness of the framing effect and fear appeals to inform young people about the risks of multiple births and the option of selecting elective single-embryo transfer (eSET). A non-patient student sample (age (mean±SD) 23±5.5 years; n=321) were randomly allocated to one of seven groups: (1) framing effect: (1a) gain and (1b) loss frame; (2) fear appeal: (2a) high, (2b) medium and (2c) low fear; or (3) a control group: (3a) education and (3b) non-education. The primary outcome measure was the Attitudes towards Single Embryo Transfer questionnaire, before exposure to the messages (time 1) and immediately afterwards (time 2). Results revealed participants in the high fear, medium fear and gain condition demonstrated the most positive and significant differences (P<0.001 to P<0.05) in their knowledge, hypothetical intentions and modest changes in attitudes towards eSET than the low fear, loss frame and education and non-education messages. The results demonstrate that the use of complex persuasive communication techniques on a student population to promote immediate and hypothetical eSET preferences is more successful at promoting eSET than merely reporting educational content. Future research should investigate its application in a clinical population. A multiple pregnancy is a health risk to both infant and mother following IVF treatment. The aims of this study were to test the effectiveness of two persuasive communication techniques (the framing effect and fear appeals) to inform young people about the risks of multiple births and the hypothetical option of selecting elective single-embryo transfer (eSET) (i.e., only one embryo is transferred to the uterus using IVF treatment). A total of 321 non-patient student sample (mean age 23) were randomly allocated to read a message from one of seven groups: (1) framing effect: (1a) gain and (1b) loss frame; (2) fear appeal: (2a) high, (2b) medium and (2c) low fear; or (3) a control group

  12. Generation of human organs in pigs via interspecies blastocyst complementation.

    PubMed

    Wu, J; Platero Luengo, A; Gil, M A; Suzuki, K; Cuello, C; Morales Valencia, M; Parrilla, I; Martinez, C A; Nohalez, A; Roca, J; Martinez, E A; Izpisua Belmonte, J C

    2016-10-01

    More than eighteen years have passed since the first derivation of human embryonic stem cells (ESCs), but their clinical use is still met with several challenges, such as ethical concerns regarding the need of human embryos, tissue rejection after transplantation and tumour formation. The generation of human induced pluripotent stem cells (iPSCs) enables the access to patient-derived pluripotent stem cells (PSCs) and opens the door for personalized medicine as tissues/organs can potentially be generated from the same genetic background as the patient recipients, thus avoiding immune rejections or complication of immunosuppression strategies. In this regard, successful replacement, or augmentation, of the function of damaged tissue by patient-derived differentiated stem cells provides a promising cell replacement therapy for many devastating human diseases. Although human iPSCs can proliferate unlimitedly in culture and harbour the potential to generate all cell types in the adult body, currently, the functionality of differentiated cells is limited. An alternative strategy to realize the full potential of human iPSC for regenerative medicine is the in vivo tissue generation in large animal species via interspecies blastocyst complementation. As this technology is still in its infancy and there remains more questions than answers, thus in this review, we mainly focus the discussion on the conceptual framework, the emerging technologies and recent advances involved with interspecies blastocyst complementation, and will refer the readers to other more in-depth reviews on dynamic pluripotent stem cell states, genome editing and interspecies chimeras. Likewise, other emerging alternatives to combat the growing shortage of human organs, such as xenotransplantation or tissue engineering, topics that has been extensively reviewed, will not be covered here.

  13. Enhanced single seed trait predictions in soybean (Glycine max) and robust calibration model transfer with near infrared reflectance spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Single seed near infrared reflectance (NIR) spectroscopy predicts soybean (Glycine max) seed quality traits of moisture, oil, and protein. We tested the accuracy of transferring calibrations between different single seed NIR analyzers of the same design by collecting NIR spectra and analytical trait...

  14. Single cell genomics indicates horizontal gene transfer and viral infections in a deep subsurface Firmicutes population

    PubMed Central

    Labonté, Jessica M.; Field, Erin K.; Lau, Maggie; Chivian, Dylan; Van Heerden, Esta; Wommack, K. Eric; Kieft, Thomas L.; Onstott, Tullis C.; Stepanauskas, Ramunas

    2015-01-01

    A major fraction of Earth's prokaryotic biomass dwells in the deep subsurface, where cellular abundances per volume of sample are lower, metabolism is slower, and generation times are longer than those in surface terrestrial and marine environments. How these conditions impact biotic interactions and evolutionary processes is largely unknown. Here we employed single cell genomics to analyze cell-to-cell genome content variability and signatures of horizontal gene transfer (HGT) and viral infections in five cells of Candidatus Desulforudis audaxviator, which were collected from a 3 km-deep fracture water in the 2.9 Ga-old Witwatersrand Basin of South Africa. Between 0 and 32% of genes recovered from single cells were not present in the original, metagenomic assembly of Desulforudis, which was obtained from a neighboring subsurface fracture. We found a transposable prophage, a retron, multiple clustered regularly interspaced short palindromic repeats (CRISPRs) and restriction-modification systems, and an unusually high frequency of transposases in the analyzed single cell genomes. This indicates that recombination, HGT and viral infections are prevalent evolutionary events in the studied population of microorganisms inhabiting a highly stable deep subsurface environment. PMID:25954269

  15. Single step high-speed printing of continuous silver lines by laser-induced forward transfer

    NASA Astrophysics Data System (ADS)

    Puerto, D.; Biver, E.; Alloncle, A.-P.; Delaporte, Ph.

    2016-06-01

    The development of high-speed ink printing process by Laser-Induced Forward Transfer (LIFT) is of great interest for the printing community. To address the problems and the limitations of this process that have been previously identified, we have performed an experimental study on laser micro-printing of silver nanoparticle inks by LIFT and demonstrated for the first time the printing of continuous conductive lines in a single pass at velocities of 17 m/s using a 1 MHz repetition rate laser. We investigated the printing process by means of a time-resolved imaging technique to visualize the ejection dynamics of single and adjacent jets. The control of the donor film properties is of prime importance to achieve single step printing of continuous lines at high velocities. We use a 30 ps pulse duration laser with a wavelength of 343 nm and a repetition rate from 0.2 to 1 MHz. A galvanometric mirror head controls the distance between two consecutives jets by scanning the focused beam along an ink-coated donor substrate at different velocities. Droplets and lines of silver inks are laser-printed on glass and PET flexible substrates and we characterized their morphological quality by atomic force microscope (AFM) and optical microscope.

  16. Single Molecule Nanospectroscopy Visualizes Proton-Transfer Processes within a Zeolite Crystal

    PubMed Central

    2016-01-01

    Visualizing proton-transfer processes at the nanoscale is essential for understanding the reactivity of zeolite-based catalyst materials. In this work, the Brønsted-acid-catalyzed oligomerization of styrene derivatives was used for the first time as a single molecule probe reaction to study the reactivity of individual zeolite H-ZSM-5 crystals in different zeolite framework, reactant and solvent environments. This was accomplished via the formation of distinct dimeric and trimeric fluorescent carbocations, characterized by their different photostability, as detected by single molecule fluorescence microscopy. The oligomerization kinetics turned out to be very sensitive to the reaction conditions and the presence of the local structural defects in zeolite H-ZSM-5 crystals. The remarkably photostable trimeric carbocations were found to be formed predominantly near defect-rich crystalline regions. This spectroscopic marker offers clear prospects for nanoscale quality control of zeolite-based materials. Interestingly, replacing n-heptane with 1-butanol as a solvent led to a reactivity decrease of several orders and shorter survival times of fluorescent products due to the strong chemisorption of 1-butanol onto the Brønsted acid sites. A similar effect was achieved by changing the electrophilic character of the para-substituent of the styrene moiety. Based on the measured turnover rates we have established a quantitative, single turnover approach to evaluate substituent and solvent effects on the reactivity of individual zeolite H-ZSM-5 crystals. PMID:27709925

  17. Heat transfer from combustion gases to a single row of closely spaced tubes in a swirl crossflow Stirling engine heater

    NASA Technical Reports Server (NTRS)

    Bankston, C. P.; Back, L. H.

    1982-01-01

    This paper describes an experimental program to determine the heat-transfer characteristics of a combustor and heat-exchanger system in a hybrid solar receiver which utilizes a Stirling engine. The system consists of a swirl combustor with a crossflow heat exchanger composed of a single row of 48 closely spaced curved tubes. In the present study, heat-transfer characteristics of the combustor/heat-exchanger system without a Stirling engine have been studied over a range of operating conditions and output levels using water as the working fluid. Nondimensional heat-transfer coefficients based on total heat transfer have been obtained and are compared with available literature data. The results show significantly enhanced heat transfer for the present geometry and test conditions. Also, heat transfer along the length of the tubes is found to vary, the effect depending upon test condition.

  18. Single electron transfer in He+-He+ collision and production of helium atom

    NASA Astrophysics Data System (ADS)

    Azizan, Shima; Fathi, Reza; Shojaei, Farideh

    2017-02-01

    The four body Born distorted wave (BDW-4B) approximation with correct boundary condition is used for single electron transfer in He+-He+ collision. The post and prior total cross sections are obtained in the energy range 10-1000 keV/amu and the post-prior discrepancy is estimated. The sensitivity of the results with respect to the choice of the final helium-like ground state wave function is evaluated through two different wave functions. The importance of the dynamic electron correlations is tested as a function of impact energy. Additional experimental data at higher impact energies is needed for a better assessment of the validity of the present theory.

  19. Proposal for probing energy transfer pathway by single-molecule pump-dump experiment

    PubMed Central

    Tao, Ming-Jie; Ai, Qing; Deng, Fu-Guo; Cheng, Yuan-Chung

    2016-01-01

    The structure of Fenna-Matthews-Olson (FMO) light-harvesting complex had long been recognized as containing seven bacteriochlorophyll (BChl) molecules. Recently, an additional BChl molecule was discovered in the crystal structure of the FMO complex, which may serve as a link between baseplate and the remaining seven molecules. Here, we investigate excitation energy transfer (EET) process by simulating single-molecule pump-dump experiment in the eight-molecules complex. We adopt the coherent modified Redfield theory and non-Markovian quantum jump method to simulate EET dynamics. This scheme provides a practical approach of detecting the realistic EET pathway in BChl complexes with currently available experimental technology. And it may assist optimizing design of artificial light-harvesting devices. PMID:27277702

  20. Experimental Support for a Single Electron-Transfer Oxidation Mechanism in Firefly Bioluminescence.

    PubMed

    Branchini, Bruce R; Behney, Curran E; Southworth, Tara L; Fontaine, Danielle M; Gulick, Andrew M; Vinyard, David J; Brudvig, Gary W

    2015-06-24

    Firefly luciferase produces light by converting substrate beetle luciferin into the corresponding adenylate that it subsequently oxidizes to oxyluciferin, the emitter of bioluminescence. We have confirmed the generally held notions that the oxidation step is initiated by formation of a carbanion intermediate and that a hydroperoxide (anion) is involved. Additionally, structural evidence is presented that accounts for the delivery of oxygen to the substrate reaction site. Herein, we report key convincing spectroscopic evidence of the participation of superoxide anion in a related chemical model reaction that supports a single electron-transfer pathway for the critical oxidative process. This mechanism may be a common feature of bioluminescence processes in which light is produced by an enzyme in the absence of cofactors.

  1. Interplay between single-particle and collective excitations in argon isotopes populated by transfer reactions

    SciTech Connect

    Szilner, S.; Jelavic-Malenica, D.; Soic, N.; Corradi, L.; Fioretto, E.; Sahin, E.; Silvestri, R.; Stefanini, A. M.; Valiente-Dobon, J. J.; Haas, F.; Lebhertz, D.; Bouhelal, M.; Caurier, E.; Courtin, S.; Goasduff, A.; Nowacki, F.; Ur, C. A.; Beghini, S.; Farnea, E.

    2011-07-15

    New {gamma} transitions have been identified in argon isotopes in {sup 40}Ar + {sup 208}Pb multiple transfer reactions by exploiting, in a fragment-{gamma} measurement, the new generation of magnetic spectrometers based on trajectory reconstruction coupled to large {gamma} arrays. The coupling of single-particle degrees of freedom to nuclear vibration quanta was discussed. The interpretation of the newly observed states within a particle-phonon coupling picture was used to consistently follow, via their excitation energies, the evolution of collectivity in odd Ar isotopes. The proposed level schemes are supported by the results of sd-pf shell-model calculations, which have been also employed to evaluate the strength functions of the populated states.

  2. Proposal for probing energy transfer pathway by single-molecule pump-dump experiment

    NASA Astrophysics Data System (ADS)

    Tao, Ming-Jie; Ai, Qing; Deng, Fu-Guo; Cheng, Yuan-Chung

    2016-06-01

    The structure of Fenna-Matthews-Olson (FMO) light-harvesting complex had long been recognized as containing seven bacteriochlorophyll (BChl) molecules. Recently, an additional BChl molecule was discovered in the crystal structure of the FMO complex, which may serve as a link between baseplate and the remaining seven molecules. Here, we investigate excitation energy transfer (EET) process by simulating single-molecule pump-dump experiment in the eight-molecules complex. We adopt the coherent modified Redfield theory and non-Markovian quantum jump method to simulate EET dynamics. This scheme provides a practical approach of detecting the realistic EET pathway in BChl complexes with currently available experimental technology. And it may assist optimizing design of artificial light-harvesting devices.

  3. Single-Walled Carbon Nanotubes Alter Cytochrome C Electron Transfer and Modulate Mitochondrial Function

    PubMed Central

    Ma, Xiaowei; Zhang, Li-Hua; Wang, Li-Rong; Xue, Xue; Sun, Ji-Hong; Wu, Yan; Zou, Guozhang; Wu, Xia; Wang, Paul C.; Wamer, Wayne G.; Yin, Jun-Jie; Zheng, Kaiyuan; Liang, Xing-Jie

    2013-01-01

    Single-walled carbon nanotubes (SWCNTs) are broadly used for various biomedical applications such as drug delivery, in vivo imaging and cancer photothermal therapy due to their unique physiochemical properties. However, once they enter the cells, the effects of SWCNTs to the intracellular organelles and macromolecules are not comprehensively understood. Cytochrome c (Cyt c), as a key component of the electron transport chain in mitochondria, plays an essential role in cellular energy consumption, growth and differentiation. In this study, we found the mitochondrial membrane potential (MMP) and mitochondrial oxygen uptake were greatly decreased in human epithelial KB cells treated with SWCNTs, which accompanies the reduction of Cyt c. SWCNTs deoxidized Cyt c in a pH dependent manner as evidenced by the appearance of a 550 nm characteristic absorption peak, which intensity increased as pH increase. Circular dichroism measurement confirmed the pH-dependent conformational change, which facilitated closer association of SWCNTs with the heme pocket of Cyt c and thus expedited the reduction of Cyt c. The electron transfer of Cyt c is also disturbed by SWCNTs, as measured with electron spin resonance spectroscopy. In conclusion, the redox activity of Cyt c was affected by SWCNTs treatment due to attenuated electron transfer and conformational change of Cyt c, which consequently changed mitochondrial respiration of SWCNTs treated cells. This work is significant to SWCNTs research because it provided novel understanding to the disruption of SWCNTs to the mitochondria and has important implications for biomedical applications of SWCNTs. PMID:23171082

  4. The location of "8"-shaped hatching influences inner cell mass formation in mouse blastocysts.

    PubMed

    Onodera, Yohei; Takahashi, Kazumasa; Goto, Mayumi; Anzai, Mibuki; Ono, Natsuki; Shirasawa, Hiromitsu; Sato, Wataru; Miura, Hiroshi; Sato, Naoki; Sato, Akira; Kumazawa, Yukiyo; Terada, Yukihiro

    2017-01-01

    The hatching of a blastocyst where the blastocyst portions on the inside and the outside of the zona pellucida feature a figure-of-eight shape is termed "8"-shaped hatching; this type of hatching has been reported to affect the proper presentation of the inner cell mass (ICM) in both human and mouse embryos. Here, our aim was to investigate the factors that affect ICM presentation during "8"-shaped hatching. We performed IVF by using B6D2F1 female mice and ICR male mice, and used the 104 captured blastocysts. Embryos were maintained in KSOM at 37°C in a 5% CO2, 5% O2, and 90% N2 environment, and their growth behavior was monitored individually and continuously using time-lapse cinematography. At 120 h after insemination, embryos were immunostained and examined under a confocal microscope. We used the hatching form to identify "8"-shaped hatching, and we classified the "8"-shaped-hatching blastocysts into two groups, one in which the hatching site was near the ICM center, and the other in which the hatching site was far from the ICM center. We measured each group for ICM size and the number of Oct3/4-positive cells. Of the 95 hatching or hatched embryos, 74 were "8"-shaped-hatching blastocysts, and in these embryos, the ICM was significantly wider when the hatching site was near the ICM than when the hatching site was far from the ICM (P = 0.0091). Moreover, in the "8"-shaped-hatching blastocysts in which the ICM was included in the blastocyst portion outside the zona pellucida-the portion defined as the "outside blastocyst"-after the collapse of this outside blastocyst, the ICM adhered to the trophectoderm of the outside blastocyst, opposite the hatching site. Our results indicate that in "8"-shaped-hatching blastocysts, the hatching site and the collapse of outside blastocyst affect ICM formation. Thus, the assessment of "8"-shaped hatching behaviors could yield indices for accurately evaluating embryo quality.

  5. Lipid-rich bovine serum albumin improves the viability and hatching ability of porcine blastocysts produced in vitro

    PubMed Central

    SUZUKI, Chie; SAKAGUCHI, Yosuke; HOSHI, Hiroyoshi; YOSHIOKA, Koji

    2015-01-01

    The effects of lipid-rich bovine serum albumin (LR-BSA) on the development of porcine blastocysts produced in vitro were examined. Addition of 0.5 to 5 mg/ml LR-BSA to porcine blastocyst medium (PBM) from Day 5 (Day 0 = in vitro fertilization) significantly increased the hatching rates of blastocysts on Day 7 and the total cell numbers in Day-7 blastocysts. When Day-5 blastocysts were cultured with PBM alone, PBM containing LR-BSA, recombinant human serum albumin or fatty acid-free BSA, addition of LR-BSA significantly enhanced hatching rates and the cell number in blastocysts that survived compared with other treatments. The diameter, ATP content and numbers of both inner cell mass and total cells in Day-6 and Day-7 blastocysts cultured with PBM containing LR-BSA were significantly higher than in blastocysts cultured with PBM alone, whereas LR-BSA had no effect on mitochondrial membrane potential. The mRNA levels of enzymes involved in fatty acid metabolism and β-oxidation (ACSL1, ACSL3, CPT1, CPT2 and KAT) in Day-7 blastocysts were significantly upregulated by the addition of LR-BSA. The results indicated that LR-BSA enhanced hatching ability and quality of porcine blastocysts produced in vitro, as determined by ATP content, blastocyst diameter and expression levels of the specific genes, suggesting that the stimulatory effects of LR-BSA arise from lipids bound to albumin. PMID:26582048

  6. Lipid-rich bovine serum albumin improves the viability and hatching ability of porcine blastocysts produced in vitro.

    PubMed

    Suzuki, Chie; Sakaguchi, Yosuke; Hoshi, Hiroyoshi; Yoshioka, Koji

    2016-01-01

    The effects of lipid-rich bovine serum albumin (LR-BSA) on the development of porcine blastocysts produced in vitro were examined. Addition of 0.5 to 5 mg/ml LR-BSA to porcine blastocyst medium (PBM) from Day 5 (Day 0 = in vitro fertilization) significantly increased the hatching rates of blastocysts on Day 7 and the total cell numbers in Day-7 blastocysts. When Day-5 blastocysts were cultured with PBM alone, PBM containing LR-BSA, recombinant human serum albumin or fatty acid-free BSA, addition of LR-BSA significantly enhanced hatching rates and the cell number in blastocysts that survived compared with other treatments. The diameter, ATP content and numbers of both inner cell mass and total cells in Day-6 and Day-7 blastocysts cultured with PBM containing LR-BSA were significantly higher than in blastocysts cultured with PBM alone, whereas LR-BSA had no effect on mitochondrial membrane potential. The mRNA levels of enzymes involved in fatty acid metabolism and β-oxidation (ACSL1, ACSL3, CPT1, CPT2 and KAT) in Day-7 blastocysts were significantly upregulated by the addition of LR-BSA. The results indicated that LR-BSA enhanced hatching ability and quality of porcine blastocysts produced in vitro, as determined by ATP content, blastocyst diameter and expression levels of the specific genes, suggesting that the stimulatory effects of LR-BSA arise from lipids bound to albumin.

  7. Accumulation of RNA in blastocysts during embryonic diapause and the periimplantation period in the western spotted skunk

    SciTech Connect

    Mead, R.A.; Rourke, A.W.

    1985-07-01

    The in vivo incorporation of TH-uridine into RNA was studied in delayed implanting and activated blastocysts obtained from 33 western spotted skunks. TH-uridine was incorporated into RNA by all blastocysts; however, significantly more label was incorporated as blastocyst diameter increased. Activated blastocysts with diameters of 1.6 mm or greater on average incorporated 65 times more TH-precursor in 5 hr than diapausing blastocysts with diameters of 1.1 mm or less. Polyadenylated RNA was likewise synthesized by delayed implanting and activated skunk blastocysts; however, the proportion of polyadenylated RNA synthesized by the former was greater than in the latter. The data suggest that the transition from embryonic diapause to fully activated blastocysts first occurs gradually for several days before entering a 1-2-day period of rapid development characterized by an abrupt increase in RNA accumulation.

  8. Coherence Preservation of a Single Neutral Atom Qubit Transferred between Magic-Intensity Optical Traps

    NASA Astrophysics Data System (ADS)

    Yang, Jiaheng; He, Xiaodong; Guo, Ruijun; Xu, Peng; Wang, Kunpeng; Sheng, Cheng; Liu, Min; Wang, Jin; Derevianko, Andrei; Zhan, Mingsheng

    2016-09-01

    We demonstrate that the coherence of a single mobile atomic qubit can be well preserved during a transfer process among different optical dipole traps (ODTs). This is a prerequisite step in realizing a large-scale neutral atom quantum information processing platform. A qubit encoded in the hyperfine manifold of an 87Rb atom is dynamically extracted from the static quantum register by an auxiliary moving ODT and reinserted into the static ODT. Previous experiments were limited by decoherences induced by the differential light shifts of qubit states. Here, we apply a magic-intensity trapping technique which mitigates the detrimental effects of light shifts and substantially enhances the coherence time to 225 ±21 ms . The experimentally demonstrated magic trapping technique relies on the previously neglected hyperpolarizability contribution to the light shifts, which makes the light shift dependence on the trapping laser intensity parabolic. Because of the parabolic dependence, at a certain "magic" intensity, the first order sensitivity to trapping light-intensity variations over ODT volume is eliminated. We experimentally demonstrate the utility of this approach and measure hyperpolarizability for the first time. Our results pave the way for constructing scalable quantum-computing architectures with single atoms trapped in an array of magic ODTs.

  9. Group transfer theory of single molecule imaging experiments in the F-ATPase biomolecular motor

    NASA Astrophysics Data System (ADS)

    Volkan-Kacso, Sandor; Marcus, Rudolph

    I describe a chemo-mechanical theory to treat single molecule imaging and ``stalling'' experiments on the F-ATPase enzyme. This enzyme is an effective stepping biomolecular rotary motor with a rotor shaft and a stator ring. Using group transfer theoretical approach the proposed structure-based theory couples the binding transition of nucleotides in the stator subunits and the physics of torsional elasticity in the rotor. The twisting of the elastic rotor domain acts as a perturbation upon the driving potential, the Gibbs free energy. In the theory, without the use of adjustastable parameters, we predict the rate and equilibrium constant dependence of steps such as ATP binding and phosphate release as a function of manipulated rotor angle. Then we compare these predictions to available data from stalling experiments. Besides treating experiments, the theory can provide guides for atomistic simulations, which could calculate the reorganization parameter and the torsional spring constant. The framework is generic and I discuss its application to other single molecule experiments, such as controlled rotation and other biomolecular motors, including motor-DNA complexes and linear motors.[PNAS, Early Edition, Oct. 19, 2015, doi: 10.1073/pnas.1518489112] The authors would like to acknowledge support from the Office of the Naval Research, the Army Research Office, and the James W. Glanville Foundation.

  10. Group transfer theory of single molecule imaging experiments in the F-ATPase biomolecular motor

    NASA Astrophysics Data System (ADS)

    Volkan-Kacso, Sandor; Marcus, Rudolph

    I describe a chemo-mechanical theory to treat single molecule imaging and ``stalling'' experiments on the F-ATPase enzyme. This enzyme is an effective stepping biomolecular rotary motor with a rotor shaft and a stator ring. Using group transfer theoretical approach the proposed structure-based theory couples the binding transition of nucleotides in the stator subunits and the physics of torsional elasticity in the rotor. The twisting of the elastic rotor domain acts as a perturbation upon the driving potential, the Gibbs free energy. In the theory, without the use of adjustastable parameters, we predict the rate and equilibrium constant dependence of steps such as ATP binding and phosphate release as a function of manipulated rotor angle. Then we compare these predictions to available data from stalling experiments. Besides treating experiments, the theory can provide guides for atomistic simulations, which could calculate the reorganization parameter and the torsional spring constant. The framework is generic and I discuss its application to other single molecule experiments, such as controlled rotation and other biomolecular motors, including motor-DNA complexes and linear motors.[PNAS, Early Edition, Oct. 19, 2015, doi: 10.1073/pnas.1518489112

  11. Drug transport mechanism of P-glycoprotein monitored by single molecule fluorescence resonance energy transfer

    NASA Astrophysics Data System (ADS)

    Ernst, S.; Verhalen, B.; Zarrabi, N.; Wilkens, S.; Börsch, M.

    2011-03-01

    In this work we monitor the catalytic mechanism of P-glycoprotein (Pgp) using single-molecule fluorescence resonance energy transfer (FRET). Pgp, a member of the ATP binding cassette family of transport proteins, is found in the plasma membrane of animal cells where it is involved in the ATP hydrolysis driven export of hydrophobic molecules. When expressed in the plasma membrane of cancer cells, the transport activity of Pgp can lead to the failure of chemotherapy by excluding the mostly hydrophobic drugs from the interior of the cell. Despite ongoing effort, the catalytic mechanism by which Pgp couples MgATP binding and hydrolysis to translocation of drug molecules across the lipid bilayer is poorly understood. Using site directed mutagenesis, we have introduced cysteine residues for fluorescence labeling into different regions of the nucleotide binding domains (NBDs) of Pgp. Double-labeled single Pgp molecules showed fluctuating FRET efficiencies during drug stimulated ATP hydrolysis suggesting that the NBDs undergo significant movements during catalysis. Duty cycle-optimized alternating laser excitation (DCO-ALEX) is applied to minimize FRET artifacts and to select the appropriate molecules. The data show that Pgp is a highly dynamic enzyme that appears to fluctuate between at least two major conformations during steady state turnover.

  12. Toward automated denoising of single molecular Förster resonance energy transfer data

    NASA Astrophysics Data System (ADS)

    Lee, Hao-Chih; Lin, Bo-Lin; Chang, Wei-Hau; Tu, I.-Ping

    2012-01-01

    A wide-field two-channel fluorescence microscope is a powerful tool as it allows for the study of conformation dynamics of hundreds to thousands of immobilized single molecules by Förster resonance energy transfer (FRET) signals. To date, the data reduction from a movie to a final set containing meaningful single-molecule FRET (smFRET) traces involves human inspection and intervention at several critical steps, greatly hampering the efficiency at the post-imaging stage. To facilitate the data reduction from smFRET movies to smFRET traces and to address the noise-limited issues, we developed a statistical denoising system toward fully automated processing. This data reduction system has embedded several novel approaches. First, as to background subtraction, high-order singular value decomposition (HOSVD) method is employed to extract spatial and temporal features. Second, to register and map the two color channels, the spots representing bleeding through the donor channel to the acceptor channel are used. Finally, correlation analysis and likelihood ratio statistic for the change point detection (CPD) are developed to study the two channels simultaneously, resolve FRET states, and report the dwelling time of each state. The performance of our method has been checked using both simulation and real data.

  13. Coherence Preservation of a Single Neutral Atom Qubit Transferred between Magic-Intensity Optical Traps.

    PubMed

    Yang, Jiaheng; He, Xiaodong; Guo, Ruijun; Xu, Peng; Wang, Kunpeng; Sheng, Cheng; Liu, Min; Wang, Jin; Derevianko, Andrei; Zhan, Mingsheng

    2016-09-16

    We demonstrate that the coherence of a single mobile atomic qubit can be well preserved during a transfer process among different optical dipole traps (ODTs). This is a prerequisite step in realizing a large-scale neutral atom quantum information processing platform. A qubit encoded in the hyperfine manifold of an ^{87}Rb atom is dynamically extracted from the static quantum register by an auxiliary moving ODT and reinserted into the static ODT. Previous experiments were limited by decoherences induced by the differential light shifts of qubit states. Here, we apply a magic-intensity trapping technique which mitigates the detrimental effects of light shifts and substantially enhances the coherence time to 225±21  ms. The experimentally demonstrated magic trapping technique relies on the previously neglected hyperpolarizability contribution to the light shifts, which makes the light shift dependence on the trapping laser intensity parabolic. Because of the parabolic dependence, at a certain "magic" intensity, the first order sensitivity to trapping light-intensity variations over ODT volume is eliminated. We experimentally demonstrate the utility of this approach and measure hyperpolarizability for the first time. Our results pave the way for constructing scalable quantum-computing architectures with single atoms trapped in an array of magic ODTs.

  14. In-straw cryoprotectant dilution of IVP bovine blastocysts vitrified in hand-pulled glass micropipettes.

    PubMed

    Vieira, A D; Forell, F; Feltrin, C; Rodrigues, J L

    2007-06-01

    The aim of this study was to determine the influence of two ethylene glycol-based vitrification solutions on in vitro and in vivo survival after in-straw cryoprotectant dilution of vitrified in vitro-produced bovine embryos. Day-7 expanded blastocysts were selected according to diameter (> or = 180 microm) and osmotic characteristics and randomly assigned to one of three groups (i) VSa: vitrification in 40% EG+17.1% SUC+0.1% PVA; (ii) VSb: vitrification in 20% EG+20% DMSO; (iii) control: non-vitrified embryos. Vitrification was performed in hand-pulled glass micropipettes (GMP) and cryoprotectant dilution in 0.25 ml straws after warming in a plastic tube. Embryo viability was assessed by re-expansion and hatching rates after 72 h of IVC and by pregnancy rates after direct transfer of vitrified embryos. No differences in re-expansion rates were observed between vitrified groups after 24 h in culture (VSa=84.5%; VSb=94.8%). However, fewer VSa embryos (55.2%, P<0.05) hatched after 72 h than the VSb (75.8%) and control embryos (80.0%). To evaluate in vivo viability, vitrified embryos (VSa=20; VSb=21) were warmed under field conditions and individually transferred to synchronous recipients. Pregnancy rates (day 60) were similar between groups (VSa=20%; VSb=19%). Greater hatching rates occurred after 72 h of IVC for EG+DMSO than EG+SUC+PVA vitrification solutions. However, using a GMP vitrification container and in-tube warming, both solutions provided similar pregnancy rates after the in-straw cryoprotectant dilution and direct embryo transfer.

  15. Ultrafast single-electron transfer in coupled quantum dots driven by a few-cycle chirped pulse

    SciTech Connect

    Yang, Wen-Xing; Chen, Ai-Xi; Bai, Yanfeng; Lee, Ray-Kuang

    2014-04-14

    We theoretically study the ultrafast transfer of a single electron between the ground states of a coupled double quantum dot (QD) structure driven by a nonlinear chirped few-cycle laser pulse. A time-dependent Schrödinger equation without the rotating wave approximation is solved numerically. We demonstrate numerically the possibility to have a complete transfer of a single electron by choosing appropriate values of chirped rate parameters and the intensity of the pulse. Even in the presence of the spontaneous emission and dephasing processes of the QD system, high-efficiency coherent transfer of a single electron can be obtained in a wide range of the pulse parameters. Our results illustrate the potential to utilize few-cycle pulses for the excitation in coupled quantum dot systems through the nonlinear chirp parameter control, as well as a guidance in the design of experimental implementation.

  16. Combining MFD and PIE for accurate single-pair Förster resonance energy transfer measurements.

    PubMed

    Kudryavtsev, Volodymyr; Sikor, Martin; Kalinin, Stanislav; Mokranjac, Dejana; Seidel, Claus A M; Lamb, Don C

    2012-03-01

    Single-pair Förster resonance energy transfer (spFRET) experiments using single-molecule burst analysis on a confocal microscope are an ideal tool to measure inter- and intramolecular distances and dynamics on the nanoscale. Different techniques have been developed to maximize the amount of information available in spFRET burst analysis experiments. Multiparameter fluorescence detection (MFD) is used to monitor a variety of fluorescence parameters simultaneously and pulsed interleaved excitation (PIE) employs direct excitation of the acceptor to probe its presence and photoactivity. To calculate accurate FRET efficiencies from spFRET experiments with MFD or PIE, several calibration measurements are usually required. Herein, we demonstrate that by combining MFD with PIE information regarding all calibration factors as well as an accurate determination of spFRET histograms can be performed in a single measurement. In addition, the quality of overlap of the different detection volumes as well as the detection of acceptor photophysics can be investigated with MFD-PIE. Bursts containing acceptor photobleaching can be identified and excluded from further investigation while bursts that contain FRET dynamics are unaffected by this analysis. We have employed MFD-PIE to accurately analyze the effects of nucleotides and substrate on the interdomain separation in DnaK, the major bacterial heat shock protein 70 (Hsp70). The interdomain distance increases from 47 Å in the ATP-bound state to 84 Å in the ADP-bound state and slightly contracts to 77 Å when a substrate is bound. This is in contrast to what was observed for the mitochondrial member of the Hsp70s, Ssc1, supporting the notion of evolutionary specialization of Hsp70s for different cellular functions in different organisms and cell organelles.

  17. Cryotolerance and global gene-expression patterns of Bos taurus indicus and Bos taurus taurus in vitro- and in vivo-produced blastocysts.

    PubMed

    Sudano, Mateus J; Caixeta, Ester S; Paschoal, Daniela M; Martins, Alicio; Machado, Rui; Buratini, José; Landim-Alvarenga, Fernanda D C

    2014-10-01

    In a 2×2 factorial experimental design, embryo development, cryotolerance and global gene expression of Nellore (Bos taurus indicus) and Simmental (Bos taurus taurus) blastocysts produced in vitro (IVP) and in vivo (multiple ovulation derived embryo, MODE) were assessed. Blastocyst production was higher in Nellore than in Simmental (47.7±2.0% vs 27.0±2.0%) cows. The total numbers of ova or embryos recovered (5.5±0.9 vs 3.7±0.8) and transferable embryos (3.8±1.0 vs 2.3±0.8) per cow were not different between breeds. Simmental and MODE (34.6% and 38.5%, n=75 and 70) blastocysts had higher survival rates after cryopreservation compared with Nellore and IVP (20.2% and 18.1%, n=89 and 94) embryos, respectively. Differences between transcriptomes were addressed by principal-component analysis, which indicated that gene expression was affected by subspecies (158 genes), origin (532 genes) and interaction between both subspecies and origin (53 genes). Several functional processes and pathways relevant to lipid metabolism and embryo viability involving differentially expressed genes were identified. The lipid metabolism-related genes were upregulated in Simmental (AUH and ELOVL6) and IVP (ACSL3 and ACSL6) blastocysts. The expression profiles of genes related to mitochondrial metabolism (ATP5B), oxidative stress (GPX4), apoptosis (DAD1, DAP, PRDX2), heat shock (HSPA5), pregnancy (IFNT2, PAG2) and cell differentiation (KRT18) varied between experimental groups.

  18. Zygote injection of CRISPR/Cas9 RNA successfully modifies the target gene without delaying blastocyst development or altering the sex ratio in pigs.

    PubMed

    Whitworth, Kristin M; Benne, Joshua A; Spate, Lee D; Murphy, Stephanie L; Samuel, Melissa S; Murphy, Clifton N; Richt, Jürgen A; Walters, Eric; Prather, Randall S; Wells, Kevin D

    2017-02-01

    The CRISPR/Cas9 genome editing tool has increased the efficiency of creating genetically modified pigs for use as biomedical or agricultural models. The objectives were to determine if DNA editing resulted in a delay in development to the blastocyst stage or in a skewing of the sex ratio. Six DNA templates (gBlocks) that were designed to express guide RNAs that target the transmembrane protease, serine S1, member 2 (TMPRSS2) gene were in vitro transcribed. Pairs of CRISPR guide RNAs that flanked the start codon and polyadenylated Cas9 were co-injected into the cytoplasm of zygotes and cultured in vitro to the blastocyst stage. Blastocysts were collected as they formed on days 5, 6 or 7. PCR was performed to determine genotype and sex of each embryo. Separately, embryos were surgically transferred into recipient gilts on day 4 of estrus. The rate of blastocyst development was not significantly different between CRISPR injection embryos or the non-injected controls at day 5, 6 or 7 (p = 0.36, 0.09, 0.63, respectively). Injection of three CRISPR sets of guides resulted in a detectable INDEL in 92-100 % of the embryos analyzed. There was not a difference in the number of edits or sex ratio of male to female embryos when compared between days 5, 6 and 7 to the controls (p > 0.22, >0.85). There were 12 resulting piglets and all 12 had biallelic edits of TMRPSS2. Zygote injection with CRISPR/Cas9 continues to be a highly efficient tool to genetically modify pig embryos.

  19. Fullerene-Assisted Photoinduced Charge Transfer of Single-Walled Carbon Nanotubes through a Flavin Helix.

    PubMed

    Mollahosseini, Mehdi; Karunaratne, Erandika; Gibson, George N; Gascón, Jose A; Papadimitrakopoulos, Fotios

    2016-05-11

    One of the greatest challenges with single-walled carbon nanotube (SWNT) photovoltaics and nanostructured devices is maintaining the nanotubes in their pristine state (i.e., devoid of aggregation and inhomogeneous doping) so that their unique spectroscopic and transport characteristics are preserved. To this effect, we report on the synthesis and self-assembly of a C60-functionalized flavin (FC60), composed of PCBM and isoalloxazine moieties attached on either ends of a linear, C-12 aliphatic spacer. Small amounts of FC60 (up to 3 molar %) were shown to coassembly with an organic soluble derivative of flavin (FC12) around SWNTs and impart effective dispersion and individualization. A key annealing step was necessary to perfect the isoalloxazine helix and expel the C60 moiety away from the nanotubes. Steady-state and transient absorption spectroscopy illustrate that 1% or higher incorporation of FC60 allows for an effective photoinduced charge transfer quenching of the encased SWNTs through the seamless helical encase. This is enabled via the direct π-π overlap between the graphene sidewalls, isoalloxazine helix, and the C60 cage that facilitates SWNT exciton dissociation and electron transfer to the PCBM moiety. Atomistic molecular simulations indicate that the stability of the complex originates from enhanced van der Waals interactions of the flexible spacer wrapped around the fullerene that brings the C60 in π-π overlap with the isoalloxazine helix. The remarkable spectral purity (in terms of narrow E(S)ii line widths) for the resulting ground-state complex signals a new class of highly organized supramolecular nanotube architecture with profound importance for advanced nanostructured devices.

  20. In vitro development of OPU-derived bovine embryos cultured either individually or in groups with the silk protein sericin and the viability of frozen-thawed embryos after transfer.

    PubMed

    Isobe, Tomohiro; Ikebata, Yoshihisa; Do, Lanh Thi Kim; Tanihara, Fuminori; Taniguchi, Masayasu; Otoi, Takeshige

    2015-07-01

    The optimization of single-embryo culture conditions is very important, particularly in the in vitro production of bovine embryos using the ovum pick-up (OPU) procedure. The purpose of this study was to examine the development of embryos derived from oocytes obtained by OPU that were cultured either individually or in groups in medium supplemented with or without sericin and to investigate the viability of the frozen-thawed embryos after a direct transfer. When two-cell-stage embryos were cultured either individually or in groups for 7 days in CR1aa medium supplemented with or without 0.5% sericin, the rates of development to blastocysts and freezable blastocysts were significantly lower for the embryos cultured individually without sericin than for the embryos cultured in groups with or without sericin. Moreover, the rate of development to freezable blastocysts of the embryos cultured individually with sericin was significantly higher than that of the embryos cultured without sericin. When the frozen-thawed embryos were transferred directly to recipients, the rates of pregnancy, abortion, stillbirth and normal calving in the recipients were similar among the groups, irrespective of the culture conditions and sericin supplementation. Our findings indicate that supplementation with sericin during embryo culture improves the quality of the embryos cultured individually but not the viability of the frozen-thawed embryos after transfer to recipients.

  1. Stem cells and lineage development in the mammalian blastocyst.

    PubMed

    Rossant, Janet

    2007-01-01

    The mammalian blastocyst is the source of the most pluripotent stem cells known: embryonic stem (ES) cells. However, ES cells are not totipotent; in mouse chimeras, they do not contribute to extra-embryonic cell types of the trophectoderm (TE) and primitive endoderm (PrE) lineages. Understanding the genetic pathways that control pluripotency v. extra-embryonic lineage restriction is key to understanding not only normal embryonic development, but also how to reprogramme adult cells to pluripotency. The trophectoderm and primitive endoderm lineages also provide the first signals that drive patterned differentiation of the pluripotent epiblast cells of the embryo. My laboratory has produced permanent mouse cell lines from both the TE and the PrE, termed trophoblast stem (TS) and eXtra-embryonic ENdoderm (XEN) cells. We have used these cells to explore the genetic and molecular hierarchy of lineage restriction and identify the key factors that distinguish the ES cell v. the TS or XEN cell fate. The major molecular pathways of lineage commitment defined in mouse embryos and stem cells are probably conserved across mammalian species, but more comparative studies of lineage development in embryos of non-rodent mammals will likely yield interesting differences in terms of timing and details.

  2. Repeated growth and bubbling transfer of graphene with millimetre-size single-crystal grains using platinum

    PubMed Central

    Gao, Libo; Ren, Wencai; Xu, Huilong; Jin, Li; Wang, Zhenxing; Ma, Teng; Ma, Lai-Peng; Zhang, Zhiyong; Fu, Qiang; Peng, Lian-Mao; Bao, Xinhe; Cheng, Hui-Ming

    2012-01-01

    Large single-crystal graphene is highly desired and important for the applications of graphene in electronics, as grain boundaries between graphene grains markedly degrade its quality and properties. Here we report the growth of millimetre-sized hexagonal single-crystal graphene and graphene films joined from such grains on Pt by ambient-pressure chemical vapour deposition. We report a bubbling method to transfer these single graphene grains and graphene films to arbitrary substrate, which is nondestructive not only to graphene, but also to the Pt substrates. The Pt substrates can be repeatedly used for graphene growth. The graphene shows high crystal quality with the reported lowest wrinkle height of 0.8 nm and a carrier mobility of greater than 7,100 cm2 V−1 s−1 under ambient conditions. The repeatable growth of graphene with large single-crystal grains on Pt and its nondestructive transfer may enable various applications. PMID:22426220

  3. The pig blastocyst: its ultrastructure and the uptake of protein macromolecules.

    PubMed

    Stroband, H W; Taverne, N; vd Bogaard, M

    1984-01-01

    Between days 8 and 11 of pregnancy spherical blastocysts from 0.3 to 10 mm in diameter were flushed from the uterine horns of Dutch Landrace pigs. A description of their ultrastructure is given, and the uptake of horseradish peroxidase and ferritin is demonstrated. The ultrastructure of the trophoblast was similar at all ages studied. The trophoblast which has many apical microvilli is able to take up and digest the macromolecules which were offered in the in vitro incubation medium. The hypoblast consists of flattened cells. In blastocysts 2 mm and larger, compact cells bearing microvilli are found below the embryoblast. Cell organelles indicating protein synthesis are found within hypoblast cells of such blastocysts. In the embryoblast, local concentrations of cell organelles are visible, indicating that differentiation has started. After the disappearance of Rauber's layer, which takes place when the blastocyst reaches a diameter of about 2 mm, superficial embryoblast cells develop short microvilli. The cells do not absorb ferritin or peroxidase but are dependent on the trophoblast for their food requirements. All cell layers in the blastocyst contain mitochondria that have characteristics of those found in steroid-producing cells. The significance of the uptake and digestion of macromolecules by trophoblast cells, the synthesis of protein by hypoblast cells and the possible synthesis of steroids is discussed with respect to the relationship between the cell layers of the blastocyst and in the context of concepto-maternal relationships.

  4. Effect of exposure to heatwave during blastocyst formation on reproductive performance of female rabbits.

    PubMed

    Marco-Jiménez, F; Naturil-Alfonso, C; Peñaranda, D S; Jiménez-Trigos, E; García-Diego, F J; Vicente, J S

    2014-08-01

    We examined the effect of female exposure to heatwave during blastocyst formation on their reproductive performance and its effect on transcriptome in blastocyst and endometrial tissue. In this study, a total of 72 rabbit does were artificially inseminated and divided into two environmental groups 2 days later: does under conventional conditions (maintained between 14-22°C, n = 29) and does heat stressed in a climatic chamber (maintained between 32-37°C, n = 43). The heat-stressed group were kept under these conditions for 3 days and returned to conventional conditions thereafter. Five days post-insemination, 48 does were slaughtered to collect blastocyst and endometrium samples. mRNA transcripts from OCT-4, VEGF, erbB3, Ifn-ɣ, HSP70 and HSP90 were analysed by qRT-PCR. At day 12 of gestation, 24 females were examined by laparoscopy to evaluate implanted embryos and at birth the total kits born and individual weights were recorded. Results revealed no gene expression changes in blastocyst and endometrial tissue under heatwave exposure. Moreover, our results demonstrated that rabbit embryos developed from 8-16 cells to blastocyst during a heatwave did not affect implantation rates, total number of kits born and foetal losses. In summary, these results demonstrate that heatwave period is not a critical point in the reproductive performance of rabbits during blastocyst formation.

  5. Human Blastocyst Secreted microRNA Regulate Endometrial Epithelial Cell Adhesion

    PubMed Central

    Cuman, Carly; Van Sinderen, Michelle; Gantier, Michael P.; Rainczuk, Kate; Sorby, Kelli; Rombauts, Luk; Osianlis, Tiki; Dimitriadis, Evdokia

    2015-01-01

    Successful embryo implantation requires synchronous development and communication between the blastocyst and the endometrium, however the mechanisms of communication in humans are virtually unknown. Recent studies have revealed that microRNAs (miRs) are present in bodily fluids and secreted by cells in culture. We have identified that human blastocysts differentially secrete miRs in a pattern associated with their implantation outcome. miR-661 was the most highly expressed miR in blastocyst culture media (BCM) from blastocysts that failed to implant (non-implanted) compared to blastocysts that implanted (implanted). Our results indicate a possible role for Argonaute 1 in the transport of miR-661 in non-implanted BCM and taken up by primary human endometrial epithelial cells (HEECs). miR-661 uptake by HEEC reduced trophoblast cell line spheroid attachment to HEEC via PVRL1. Our results suggest that human blastocysts alter the endometrial epithelial adhesion, the initiating event of implantation, via the secretion of miR, abnormalities in which result in implantation failure. PMID:26629549

  6. Discovery of candidate genes and pathways in the endometrium regulating ovine blastocyst growth and conceptus elongation.

    PubMed

    Satterfield, M Carey; Song, Gwonhwa; Kochan, Kelli J; Riggs, Penny K; Simmons, Rebecca M; Elsik, Christine G; Adelson, David L; Bazer, Fuller W; Zhou, Huaijun; Spencer, Thomas E

    2009-10-07

    Establishment of pregnancy in ruminants requires blastocyst growth to form an elongated conceptus that produces interferon tau, the pregnancy recognition signal, and initiates implantation. Blastocyst growth and development requires secretions from the uterine endometrium. An early increase in circulating concentrations of progesterone (P4) stimulates blastocyst growth and elongation in ruminants. This study utilized sheep as a model to identify candidate genes and regulatory networks in the endometrium that govern preimplantation blastocyst growth and development. Ewes were treated daily with either P4 or corn oil vehicle from day 1.5 after mating to either day 9 or day 12 of pregnancy when endometrium was obtained by hysterectomy. Microarray analyses revealed many differentially expressed genes in the endometria affected by day of pregnancy and early P4 treatment. In situ hybridization analyses revealed that many differentially expressed genes were expressed in a cell-specific manner within the endometrium. The Database for Annotation, Visualization, and Integrated Discovery (DAVID) was used to identify functional groups of genes and biological processes in the endometrium that are associated with growth and development of preimplantation blastocysts. Notably, biological processes affected by day of pregnancy and/or early P4 treatment included lipid biosynthesis and metabolism, angiogenesis, transport, extracellular space, defense and inflammatory response, proteolysis, amino acid transport and metabolism, and hormone metabolism. This transcriptomic data provides novel insights into the biology of endometrial function and preimplantation blastocyst growth and development in sheep.

  7. Probing Electron Transfer Mechanisms in Shewanella oneidensis MR-1 using a Nanoelectrode Platform and Single-Cell Imaging

    DTIC Science & Technology

    2010-01-01

    investigate extracellu- lar electron transfer in Shewanella oneidensisMR-1,where an array of nanoholes precludes or single window allows for direct...the single-cell level (Fig. 1B) highlights the re- lative sizes of the nanohole and window openings in the insulating layer deposited over electrodes...relative to individual bacteria such as Shewanella. The nanoholes are sufficiently small to preclude direct contact of the bacterial cell body to the

  8. Laser-induced Forward Transfer for Flip-chip Packaging of Single Dies

    PubMed Central

    Kaur, Kamal S.; Van Steenberge, Geert

    2015-01-01

    Flip-chip (FC) packaging is a key technology for realizing high performance, ultra-miniaturized and high-density circuits in the micro-electronics industry. In this technique the chip and/or the substrate is bumped and the two are bonded via these conductive bumps. Many bumping techniques have been developed and intensively investigated since the introduction of the FC technology in 19601 such as stencil printing, stud bumping, evaporation and electroless/electroplating2. Despite the progress that these methods have made they all suffer from one or more than one drawbacks that need to be addressed such as cost, complex processing steps, high processing temperatures, manufacturing time and most importantly the lack of flexibility. In this paper, we demonstrate a simple and cost-effective laser-based bump forming technique known as Laser-induced Forward Transfer (LIFT)3. Using the LIFT technique a wide range of bump materials can be printed in a single-step with great flexibility, high speed and accuracy at RT. In addition, LIFT enables the bumping and bonding down to chip-scale, which is critical for fabricating ultra-miniature circuitry. PMID:25867627

  9. Single-molecule-sensitive fluorescence resonance energy transfer in freely-diffusing attoliter droplets

    SciTech Connect

    Rahmanseresht, Sheema; Ramos, Kieran P.; Gamari, Ben D.; Goldner, Lori S.; Milas, Peker

    2015-05-11

    Fluorescence resonance energy transfer (FRET) from individual, dye-labeled RNA molecules confined in freely-diffusing attoliter-volume aqueous droplets is carefully compared to FRET from unconfined RNA in solution. The use of freely-diffusing droplets is a remarkably simple and high-throughput technique that facilitates a substantial increase in signal-to-noise for single-molecular-pair FRET measurements. We show that there can be dramatic differences between FRET in solution and in droplets, which we attribute primarily to an altered pH in the confining environment. We also demonstrate that a sufficient concentration of a non-ionic surfactant mitigates this effect and restores FRET to its neutral-pH solution value. At low surfactant levels, even accounting for pH, we observe differences between the distribution of FRET values in solution and in droplets which remain unexplained. Our results will facilitate the use of nanoemulsion droplets as attoliter volume reactors for use in biophysical and biochemical assays, and also in applications such as protein crystallization or nanoparticle synthesis, where careful attention to the pH of the confined phase is required.

  10. High-Content Analysis of Breast Cancer Using Single-Cell Deep Transfer Learning.

    PubMed

    Kandaswamy, Chetak; Silva, Luís M; Alexandre, Luís A; Santos, Jorge M

    2016-03-01

    High-content analysis has revolutionized cancer drug discovery by identifying substances that alter the phenotype of a cell, which prevents tumor growth and metastasis. The high-resolution biofluorescence images from assays allow precise quantitative measures enabling the distinction of small molecules of a host cell from a tumor. In this work, we are particularly interested in the application of deep neural networks (DNNs), a cutting-edge machine learning method, to the classification of compounds in chemical mechanisms of action (MOAs). Compound classification has been performed using image-based profiling methods sometimes combined with feature reduction methods such as principal component analysis or factor analysis. In this article, we map the input features of each cell to a particular MOA class without using any treatment-level profiles or feature reduction methods. To the best of our knowledge, this is the first application of DNN in this domain, leveraging single-cell information. Furthermore, we use deep transfer learning (DTL) to alleviate the intensive and computational demanding effort of searching the huge parameter's space of a DNN. Results show that using this approach, we obtain a 30% speedup and a 2% accuracy improvement.

  11. A single residue controls electron transfer gating in photosynthetic reaction centers

    NASA Astrophysics Data System (ADS)

    Shlyk, Oksana; Samish, Ilan; Matěnová, Martina; Dulebo, Alexander; Poláková, Helena; Kaftan, David; Scherz, Avigdor

    2017-03-01

    Interquinone QA‑ → QB electron-transfer (ET) in isolated photosystem II reaction centers (PSII-RC) is protein-gated. The temperature-dependent gating frequency “k” is described by the Eyring equation till levelling off at T ≥ 240 °K. Although central to photosynthesis, the gating mechanism has not been resolved and due to experimental limitations, could not be explored in vivo. Here we mimic the temperature dependency of “k” by enlarging VD1-208, the volume of a single residue at the crossing point of the D1 and D2 PSII-RC subunits in Synechocystis 6803 whole cells. By controlling the interactions of the D1/D2 subunits, VD1-208 (or 1/T) determines the frequency of attaining an ET-active conformation. Decelerated ET, impaired photosynthesis, D1 repair rate and overall cell physiology upon increasing VD1-208 to above 130 Å3, rationalize the >99% conservation of small residues at D1-208 and its homologous motif in non-oxygenic bacteria. The experimental means and resolved mechanism are relevant for numerous transmembrane protein-gated reactions.

  12. A single residue controls electron transfer gating in photosynthetic reaction centers

    PubMed Central

    Shlyk, Oksana; Samish, Ilan; Matěnová, Martina; Dulebo, Alexander; Poláková, Helena; Kaftan, David; Scherz, Avigdor

    2017-01-01

    Interquinone QA− → QB electron-transfer (ET) in isolated photosystem II reaction centers (PSII-RC) is protein-gated. The temperature-dependent gating frequency “k” is described by the Eyring equation till levelling off at T ≥ 240 °K. Although central to photosynthesis, the gating mechanism has not been resolved and due to experimental limitations, could not be explored in vivo. Here we mimic the temperature dependency of “k” by enlarging VD1-208, the volume of a single residue at the crossing point of the D1 and D2 PSII-RC subunits in Synechocystis 6803 whole cells. By controlling the interactions of the D1/D2 subunits, VD1-208 (or 1/T) determines the frequency of attaining an ET-active conformation. Decelerated ET, impaired photosynthesis, D1 repair rate and overall cell physiology upon increasing VD1-208 to above 130 Å3, rationalize the >99% conservation of small residues at D1-208 and its homologous motif in non-oxygenic bacteria. The experimental means and resolved mechanism are relevant for numerous transmembrane protein-gated reactions. PMID:28300167

  13. Single-molecule-sensitive fluorescence resonance energy transfer in freely-diffusing attoliter droplets

    NASA Astrophysics Data System (ADS)

    Rahmanseresht, Sheema; Milas, Peker; Ramos, Kieran P.; Gamari, Ben D.; Goldner, Lori S.

    2015-05-01

    Fluorescence resonance energy transfer (FRET) from individual, dye-labeled RNA molecules confined in freely-diffusing attoliter-volume aqueous droplets is carefully compared to FRET from unconfined RNA in solution. The use of freely-diffusing droplets is a remarkably simple and high-throughput technique that facilitates a substantial increase in signal-to-noise for single-molecular-pair FRET measurements. We show that there can be dramatic differences between FRET in solution and in droplets, which we attribute primarily to an altered pH in the confining environment. We also demonstrate that a sufficient concentration of a non-ionic surfactant mitigates this effect and restores FRET to its neutral-pH solution value. At low surfactant levels, even accounting for pH, we observe differences between the distribution of FRET values in solution and in droplets which remain unexplained. Our results will facilitate the use of nanoemulsion droplets as attoliter volume reactors for use in biophysical and biochemical assays, and also in applications such as protein crystallization or nanoparticle synthesis, where careful attention to the pH of the confined phase is required.

  14. Laser-induced forward transfer for flip-chip packaging of single dies.

    PubMed

    Kaur, Kamal S; Van Steenberge, Geert

    2015-03-20

    Flip-chip (FC) packaging is a key technology for realizing high performance, ultra-miniaturized and high-density circuits in the micro-electronics industry. In this technique the chip and/or the substrate is bumped and the two are bonded via these conductive bumps. Many bumping techniques have been developed and intensively investigated since the introduction of the FC technology in 1960(1) such as stencil printing, stud bumping, evaporation and electroless/electroplating2. Despite the progress that these methods have made they all suffer from one or more than one drawbacks that need to be addressed such as cost, complex processing steps, high processing temperatures, manufacturing time and most importantly the lack of flexibility. In this paper, we demonstrate a simple and cost-effective laser-based bump forming technique known as Laser-induced Forward Transfer (LIFT)3. Using the LIFT technique a wide range of bump materials can be printed in a single-step with great flexibility, high speed and accuracy at RT. In addition, LIFT enables the bumping and bonding down to chip-scale, which is critical for fabricating ultra-miniature circuitry.

  15. 77 FR 49837 - Transfer of Outbound Single-Piece First-Class Mail International Packages and Rolls to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-17

    ...The Postal Service hereby provides notice that it has filed a request with the Postal Regulatory Commission to transfer Outbound Single-Piece First-Class Mail International Packages (Small Packets) and Rolls from the market-dominant product list to the competitive product...

  16. Enhanced Single Seed Trait Predictions in Soybean (Glycine max) and Robust Calibration Model Transfer with Near-Infrared Reflectance Spectroscopy.

    PubMed

    Hacisalihoglu, Gokhan; Gustin, Jeffery L; Louisma, Jean; Armstrong, Paul; Peter, Gary F; Walker, Alejandro R; Settles, A Mark

    2016-02-10

    Single seed near-infrared reflectance (NIR) spectroscopy predicts soybean (Glycine max) seed quality traits of moisture, oil, and protein. We tested the accuracy of transferring calibrations between different single seed NIR analyzers of the same design by collecting NIR spectra and analytical trait data for globally diverse soybean germplasm. X-ray microcomputed tomography (μCT) was used to collect seed density and shape traits to enhance the number of soybean traits that can be predicted from single seed NIR. Partial least-squares (PLS) regression gave accurate predictive models for oil, weight, volume, protein, and maximal cross-sectional area of the seed. PLS models for width, length, and density were not predictive. Although principal component analysis (PCA) of the NIR spectra showed that black seed coat color had significant signal, excluding black seeds from the calibrations did not impact model accuracies. Calibrations for oil and protein developed in this study as well as earlier calibrations for a separate NIR analyzer of the same design were used to test the ability to transfer PLS regressions between platforms. PLS models built from data collected on one NIR analyzer had minimal differences in accuracy when applied to spectra collected from a sister device. Model transfer was more robust when spectra were trimmed from 910 to 1679 nm to 955-1635 nm due to divergence of edge wavelengths between the two devices. The ability to transfer calibrations between similar single seed NIR spectrometers facilitates broader adoption of this high-throughput, nondestructive, seed phenotyping technology.

  17. Effect of clinically-related factors on in vitro blastocyst development after equine ICSI.

    PubMed

    Choi, Young-Ho; Velez, Isabel C; Macías-García, Beatriz; Riera, Fernando L; Ballard, Catherine S; Hinrichs, Katrin

    2016-04-15

    Equine intracytoplasmic sperm injection (ICSI) is being used clinically for foal production, but little information is available on factors affecting the efficiency of this procedure. We examined factors that may influence blastocyst development when ICSI is performed clinically, i.e., on oocytes recovered from live mares by transvaginal ultrasound-guided follicle aspiration (TVA), using sperm from the stallion of the client's choice. In a clinical setting, there may be a delay from the time of TVA to isolation of oocytes from the aspirated fluid. In a preliminary study, oocytes from fluid held for 1.5 h at ambient temperature (26°C-33°C) yielded 32% blastocysts; however, in experiment 1, fluid held at 32 °C for 2 h after aspiration yielded 16% blastocysts versus 23% for aspirates processed immediately. Performing TVA/ICSI throughout the year would increase production from valuable mares, but efficiency during the nonbreeding season is unknown. In addition, to reduce the possibility of infection after TVA, administration of antibiotics to the mare before TVA is indicated; however, these could affect oocyte quality. In experiment 2, follicle numbers at the time of TVA were significantly higher in December to January than for the same mares during the breeding season. Oocyte recovery rates on TVA were 60% to 66% and the blastocyst rate was 18%. An equivalent blastocyst rate (18%) was achieved after administration of ampicillin and gentamicin to mares before TVA. In experiment 3, we verified that stallion differences exist in rates of cleavage after ICSI with motile sperm. In sperm from a low-performing stallion, density-gradient centrifugation followed by swim-up was associated with significantly higher rates of cleavage (45% vs. 18%) and blastocyst development (14% vs. 0%) than those for density gradient alone. In experiment 4, parthenogenetic activation with ionomycin and 6-dimethylaminopurine yielded 40% blastocysts. Frozen-thawed sperm that were immotile

  18. Mediated Electron Transfer at Vertically Aligned Single-Walled Carbon Nanotube Electrodes During Detection of DNA Hybridization

    NASA Astrophysics Data System (ADS)

    Wallen, Rachel; Gokarn, Nirmal; Bercea, Priscila; Grzincic, Elissa; Bandyopadhyay, Krisanu

    2015-06-01

    Vertically aligned single-walled carbon nanotube (VASWCNT) assemblies are generated on cysteamine and 2-mercaptoethanol (2-ME)-functionalized gold surfaces through amide bond formation between carboxylic groups generated at the end of acid-shortened single-walled carbon nanotubes (SWCNTs) and amine groups present on the gold surfaces. Atomic force microscopy (AFM) imaging confirms the vertical alignment mode of SWCNT attachment through significant changes in surface roughness compared to bare gold surfaces and the lack of any horizontally aligned SWCNTs present. These SWCNT assemblies are further modified with an amine-terminated single-stranded probe-DNA. Subsequent hybridization of the surface-bound probe-DNA in the presence of complementary strands in solution is followed using impedance measurements in the presence of Fe(CN)6 3-/4- as the redox probe in solution, which show changes in the interfacial electrochemical properties, specifically the charge-transfer resistance, due to hybridization. In addition, hybridization of the probe-DNA is also compared when it is attached directly to the gold surfaces without any intermediary SWCNTs. Contrary to our expectations, impedance measurements show a decrease in charge-transfer resistance with time due to hybridization with 300 nM complementary DNA in solution with the probe-DNA attached to SWCNTs. In contrast, an increase in charge-transfer resistance is observed with time during hybridization when the probe-DNA is attached directly to the gold surfaces. The decrease in charge-transfer resistance during hybridization in the presence of VASWCNTs indicates an enhancement in the electron transfer process of the redox probe at the VASWCNT-modified electrode. The results suggest that VASWCNTs are acting as mediators of electron transfer, which facilitate the charge transfer of the redox probe at the electrode-solution interface.

  19. The formation of multivesicular bodies in activated blastocysts is influenced by autophagy and FGF signaling in mice

    PubMed Central

    Shin, Hyejin; Bang, Soyoung; Kim, Jiyeon; Jun, Jin Hyun; Song, Haengseok; Lim, Hyunjung Jade

    2017-01-01

    Dormant blastocysts during delayed implantation undergo autophagic activation, which is an adaptive response to prolonged survival in utero during less favorable environment. We observed that multivesicular bodies (MVBs) accumulate in the trophectoderm of dormant blastocysts upon activation for implantation. Since autophagosomes are shown to fuse with MVBs and efficient autophagic degradation requires functional MVBs, we examined if MVB formation in activated blastocysts are associated with protracted autophagic state during dormancy. We show here that autophagic activation during dormancy is one precondition for MVB formation in activated blastocysts. Furthermore, the blockade of FGF signaling with PD173074 partially interferes with MVB formation in these blastocysts, suggesting the involvement of FGFR signaling in this process. We believe that MVB formation in activated blastocysts after dormancy is a potential mechanism of clearing subcellular debris accumulated during prolonged autophagy. PMID:28155881

  20. Superoxide dismutase and taurine supplementation improves in vitro blastocyst yield from poor-quality feline oocytes.

    PubMed

    Ochota, Małgorzata; Pasieka, Anna; Niżański, Wojciech

    2016-03-15

    Blastocyst production in vitro seems to be crucial part of assisted reproduction techniques in feline species. However, the results of cats' oocyte maturation and embryo development are still lower than those in other species. The aim of this study was to evaluate whether the supplementation with superoxide dismutase (SOD) and taurine during maturation or culture would improve the blastocyst yield obtained from lower grades of oocytes, that are usually discarded, as not suitable for further in vitro purposes. To investigate the effect of antioxidants' addition, the good- and poor-quality oocytes, were cultured with the addition of 10-mmol taurine and 600 UI/mL SOD. The nuclear maturity, embryo development, and blastocyst quality were subsequently assessed. In control group, without antioxidant supplementation, significantly less poor-quality oocytes matured (42% vs. 62%) and more degenerated (35% vs. 20%), comparing to the experimental group supplemented with SOD and taurine. The amount of obtained blastocyst was much higher, when poor quality oocytes were supplemented with SOD and taurine (supplementation to IVM-4%; supplementation to IVC-5.5%; supplementation to IVM and IVC-5.9% of blastocyst), comparing to not supplemented control group (1.3%). The best blastocysts were obtained when poor oocytes had antioxidants added only during embryo culture (185 ± 13.4 blastomeres vs. 100 ± 1.5 in control). In the present study, we reported that the lower grades of oocytes can better mature and form significantly more blastocysts with better quality, when cultured with addition of SOD and taurine.

  1. Beneficial effect of melatonin on blastocyst in vitro production from heat-stressed bovine oocytes.

    PubMed

    Cebrian-Serrano, A; Salvador, I; Raga, E; Dinnyes, A; Silvestre, M A

    2013-10-01

    Melatonin may play an important role in protecting gametes and embryos from the potential harmful effects of oxidative stress. In this study, we first examined two different heat stress (HS) treatments for in vitro oocyte maturation (Experiment 1: 38.5 vs 41.0°C, during the first 20 h; Experiment 2: 38.5 vs 41.5°C, during the entire period) on bovine oocyte maturation and embryo development. Second, we tested different melatonin concentrations added to the maturation and culture medium (Experiment 3: 0, 10(-12) , 10(-9) , 10(-4)  m; Experiment 4: 0, 10(-3)  m), both with and without HS (38.5 or 41.5°C, respectively). In Experiment 1, the HS treatment resulted in a lower maturation rate and number of cells/blastocyst (C/B) and a higher blastocyst rate than that in the control group. In Experiment 2, oocytes/embryos from heat-stressed oocytes (HSO) had a lower maturation, cleavage and blastocyst rates, as well as a lower C/B compared with the control. In Experiment 3, in HSO groups, 10(-4)  m melatonin resulted in an increased blastocyst rate compared with 0 m melatonin, with a similar blastocyst rate to the non-HSO without melatonin. Melatonin did not have any effect in embryos from non-HSO groups compared with the control. In Experiment 4, 10(-3)  m melatonin produced lower cleavage and blastocyst rates in HSO and lower blastocyst rate in non-HSO when compared to melatonin-untreated oocytes/embryos. In conclusion, 10(-4)  m melatonin was found to alleviate bovine oocytes from the harmful effects of HS.

  2. Transcriptomic signature to oxidative stress exposure at the time of embryonic genome activation in bovine blastocysts.

    PubMed

    Cagnone, Gael L M; Sirard, Marc-André

    2013-04-01

    In order to understand how in vitro culture affects embryonic quality, we analyzed survival and global gene expression in bovine blastocysts after exposure to increased oxidative stress conditions. Two pro-oxidant agents, one that acts extracellularly by promoting reactive oxygen species (ROS) production (0.01 mM 2,2'-azobis (2-amidinopropane) dihydrochloride [AAPH]) or another that acts intracellularly by inhibiting glutathione synthesis (0.4 mM buthionine sulfoximine [BSO]) were added separately to in vitro culture media from Day 3 (8-16-cell stage) onward. Transcriptomic analysis was then performed on resulting Day-7 blastocysts. In the literature, these two pro-oxidant conditions were shown to induce delayed degeneration in a proportion of Day-8 blastocysts. In our experiment, no morphological difference was visible, but AAPH tended to decrease the blastocyst rate while BSO significantly reduced it, indicating a differential impact on the surviving population. At the transcriptomic level, blastocysts that survived either pro-oxidant exposure showed oxidative stress and an inflammatory response (ARRB2), although AAPH induced higher disturbances in cellular homeostasis (SERPINE1). Functional genomics of the BSO profile, however, identified differential expression of genes related to glycine metabolism and energy metabolism (TPI1). These differential features might be indicative of pre-degenerative blastocysts (IGFBP7) in the AAPH population whereas BSO exposure would select the most viable individuals (TKDP1). Together, these results illustrate how oxidative disruption of pre-attachment development is associated with systematic up-regulation of several metabolic markers. Moreover, it indicates that a better capacity to survive anti-oxidant depletion may allow for the survival of blastocysts with a quieter metabolism after compaction.

  3. Quenching of a photosensitized dye through single-electron transfer from trivalent phosphorus compounds

    PubMed

    Yasui; Tsujimoto; Itoh; Ohno

    2000-07-28

    Various types of trivalent phosphorus compounds 1 undergo single-electron transfer (SET) to the photoexcited state of rhodamine 6G (Rho+*) in aqueous acetonitrile to quench the fluorescence from Rho+*. The rate constants kp for the overall SET process were determined by the Stern-Volmer method. The rate is nearly constant at a diffusion-controlled limit in the region of E1/2(1) < 1.3 V (vs Ag/Ag+), whereas log kp depends linearly on E1/2(1) in the region of E1/2(1) > 1.3 V, the slope of the correlation line being -alphaF/RT with alpha = 0.2. The potential at which the change in dependence of log kp on E1/2(1) occurs (1.3 V) is in accordance with the value of E1/2(Rho+*) (1.22 V) that has been obtained experimentally. Thus, the SET step is exothermic when E1/2(1) < 1.3 V and endothermic when E1/2(1) > 1.3 V. The alpha-value (0.2) obtained in the endothermic region shows that the SET step from 1 to Rho+* is irreversible in this region. Trivalent phosphorus radical cation 1*+ generated in the SET step undergoes an ionic reaction with water in the solvent rapidly enough to make the SET step irreversible. In contrast, the SET from amines 2 and alkoxybenzenes 3 to Rho+* is reversible when the SET step is endothermic, meaning that the radical cations 2*+ and 3*+ generated in the SET step undergo rapid "back SET" in the ground state to regenerate 2 and 3.

  4. Blastocysts cloned from the Putian Black pig ear tissues frozen without cryoprotectant at -80 and -196 degrees Celsius for 3 yrs.

    PubMed

    Zhang, Yu-Ling; Liu, Feng-Jun; Zhuang, Yi-Fen; Wang, Xiu-Ai; Zhai, Xiao-Wei; Li, Hong-Xiang; Hong, Zhi-Yong; Chen, Jun-Jie; Zhong, Ling-Chao; Zhang, Wen-Chang

    2012-09-15

    The Putian Black pig, as one of elite cultivars of endemic species in China, has been on the verge of extinction and urgently needs protection. Somatic cell nuclear transfer (SCNT) and noncryoprotected frozen tissue technology have successfully resurrected several mammalian species. Therefore, this study explored the primary feasibility of conserving this breed using a combination of both technologies. Skin tissues obtained from the ears of adult Putian Black boars were frozen without cryoprotectant at -20, -80, or -196 °C and stored for 3 yrs. Primary cell culture, passage and subculture were performed on frozen samples after being rapidly thawed at 39 °C and on fresh pig ear tissues (control). Cloned embryos were reconstructed using fibroblasts (from frozen and fresh tissues) with enucleated oocytes. Live cell lines were obtained from tissues frozen at -80 and at -196 °C and appeared to have normal proliferative activity after passage; furthermore, they directed cloned embryos to develop to the blastocyst stage after nuclear transfer. We concluded that the population of Putian Black pig might be increased in the future by transferring cloned blastocysts into synchronized recipient pigs.

  5. Novel HDD-type SNDM ferroelectric data storage system aimed at high-speed data transfer with single probe operation.

    PubMed

    Hiranaga, Yoshiomi; Uda, Tomoya; Kurihashi, Yuichi; Tanaka, Kenkou; Cho, Yasuo

    2007-12-01

    In this study, several read/write tests were conducted using a novel ferroelectric data storage test system equipped with a spindle motor, targeted at high-speed data transfer using a single probe head. A periodically inverted signal can be read out correctly with a bit rate of 100 kbps using this test system, and 10 Mbps data transfer is also possible during writing operations. The effect of a dc-offset voltage applied to the writing waveform with high-speed probe scanning is discussed. In addition, a novel noncontact probe height control technique was adopted to solve the problem of tip abrasion.

  6. miR-142-3p as a biomarker of blastocyst implantation failure - A pilot study

    PubMed Central

    Borges Jr., Edson; Setti, Amanda Souza; Braga, Daniela P.A.F.; Geraldo, Murilo V; Figueira, Rita de Cássia S; Iaconelli Jr, Assumpto

    2016-01-01

    Objective This study aims to find whether microRNAs (miRNAs) detected in the culture medium of embryos produced in vitro could be potential biomarkers of embryo implantation. Methods Culture media samples from 36 embryos, derived from patients undergoing intracytoplasmic sperm injection (ICSI) in a private university-affiliated IVF center, were collected between January/2015 and November/2015. Samples were collected on day three and embryo transfers were performed on day five and all embryos reached the blastocyst stage. Samples were split into groups according to the embryo implantation result: Positive-Implantation-Group (n=18) or Negative-Implantation-Group (n=18). For the first analysis, samples were pooled in three sets for each group (6-7 spent media per pool). MicroRNAs were extracted from spent media and cDNA was synthesized. C. elegans miR-39 was used as RNA spike-in to normalize the gene expression analysis. The expression of microRNAs into the spent media from the Positive-Implantation-Group was compared with those from the Negative-Implantation-Group. A set of seven miRNAs (miR-21, miR-142-3p, miR-19b, miR-92a, miR-20b, miR-125a and miR148a) selected according with the literature, was tested. To check whether miRNAs could be detected in individual samples of culture media, in a second analysis, ten more samples were tested for miR-21 and miR-142-3p. Results From the sevens tested miRNAs, a significant increased expression of miR-142-3p could be noted in the Negative-Implantation-Group (P<0.001). For other three miRNAs (miR-21, miR-19b and miR-92a) a difference in expression was observed, however it did not reach a statistical significance. In addition, when ten non-redundant samples were tested to check if miRNAs could be detected in individual samples of culture media, the highly specific amplification of mature miRNAs, including miR-142-3p, could be noted. Conclusion Our findings suggest that miR-142-3p, previously described as a tumor suppressor and

  7. The influence of polyvinylpyrrolidone on freezing of bovine IVF blastocysts following biopsy.

    PubMed

    Suzuki, T; Saha, S; Sumantri, C; Takagi, M; Boediono, A

    1995-12-01

    A study was conducted to develop a better freezing protocol for in vitro developed biopsied bovine blastocysts. Biopsied blastocysts were exposed to 1.8 M ethylene glycol (EG) + 0.05 M trehalose (T) and different concentration (5, 10, and 20%) of polyvinylpyrrolidone (PVP). Exposure to the solutions alone did not affect their in vitro development (Experiment 1). Experiments 2, 3, and 4 tested the viability of biopsied blastocysts cryopreserved in 1.8 M EG + different concentrations of T (0, 0.05, 0.1, and 0.3 M), 1.8 M EG + different concentrations of PVP (0, 5, 10, and 20%), and 1.8 M EG + 0.05 M T + different concentrations of PVP (0, 5, 10, and 20%), respectively. The proportion of biopsied blastocysts that reexpanded following cryopreservation in 1.8 M EG + 0.05 M T (38.5%) and 1.8 M EG + 0.1 M T (36.1%) was significantly (P < 0.05) higher than the proportion that reexpanded in 1.8 M EG + 0.3 M T (13.9%) (Experiment 2). The viability and the percentage of embryos that developed to > 250 microns in diameter in the 5, 10, and 20% PVP groups (77.8 and 50.0%, 78.1 and 43.8%, 76.9 and 65.4%, respectively) were significantly higher than those that developed cryopreserved without PVP (55.1 and 20.7%) (Experiment 3). Optimum development of in vitro culture of frozen-thawed biopsied blastocysts was obtained using 1.8 M EG + 0.05 M T and 20% PVP. Analysis of blastocysts > 250 microns in diameter showed that the number of ICM cells of biopsied blastocysts cryopreserved in 1.8 M EG + 0.05 M T with or without PVP was not different from the number of unfrozen biopsied blastocysts. These results indicate that PVP has some beneficial effect on freezing of biopsied bovine blastocysts.

  8. Porcine circovirus type 2 detection in in vitro produced porcine blastocysts after virus sperm exposure.

    PubMed

    Galeati, Giovanna; Zannoni, Augusta; Spinaci, Marcella; Bucci, Diego; Ostanello, Fabio; Panarese, Serena; Tamanini, Carlo; Sarli, Giuseppe

    2016-04-01

    This study was aimed at assessing the capability of semen experimentally infected with porcine circovirus type 2 (PCV2) to produce porcine blastocysts PCR positive for PCV2. Embryos were obtained from in vitro maturation (IVM) and in vitro fertilization (IVF) of porcine oocytes or by parthenogenesis. Sperm suspension was exposed to PCV2b and utilized for IVF. PCV2 spiked semen did not reveal any reduction in sperm viability or motility but its ability to produce infected blastocysts was irrelevant as only one out of 15 blastocysts obtained by IVF were PCV2b; however two blastocysts were PCV2a positive. Furthermore, the presence of PCV2 was demonstrated also in embryos obtained by parthenogenesis (one out of 17 was PCV2b and one PCV2a positive). Even if PCV2 firmly attaches to the surface of spermatozoa, experimentally spiked sperm were not effective in infecting oocytes during IVF and in producing PCR positive embryos. The infected blastocysts we obtained derived most probably from infected oocytes recovered at the abattoir.

  9. FTIR microspectroscopic imaging as a new tool to distinguish chemical composition of mouse blastocyst

    NASA Astrophysics Data System (ADS)

    Thumanu, Kanjana; Tanthanuch, Waraporn; Lorthongpanich, Chanchao; Heraud, Philip; Parnpai, Rangsun

    2009-09-01

    Synchrotron-Infrared (SR-IR) mapping and Focal plane array (FPA) imaging have been applied for discrimination of the three biochemical components of the mouse blastocyst. The mouse blastocyst consists of two clusters of cells known as the inner cell mass (ICM) formed within the blastocoel cavity and the thin layer of outer cells called the trophectoderm. Using Hierachical Cluster Analysis (HCA) and Principle Component Analysis (PCA), it can be shown that the composition and distribution of biochemical components within the blastocyst show differences in the protein secondary structure and the lipid content. It is worth noting that the secondary structure of the outer layer cells indicates more distinctive β-type secondary structure. The blastocoel cavity was observed to be predominantly α-helix. Significantly, the ICM region showed the predominant high absorption intensities of lipid content (CH 2, CH 3 symmetric and asymmetric stretching around 3000-2800 cm -1). The results show agreement between both SR-IR mapping and FPA-IR imaging. We propose that the biochemical difference within the blastocyst, especially the high lipid content in the ICM region, could be involved in the process of lipid signaling during pre-implantation. The use of both techniques is shown to be significant approach for revealing the biochemical components within the blastocyst.

  10. Atypical protein kinase C couples cell sorting with primitive endoderm maturation in the mouse blastocyst.

    PubMed

    Saiz, Néstor; Grabarek, Joanna B; Sabherwal, Nitin; Papalopulu, Nancy; Plusa, Berenika

    2013-11-01

    During mouse pre-implantation development, extra-embryonic primitive endoderm (PrE) and pluripotent epiblast precursors are specified in the inner cell mass (ICM) of the early blastocyst in a 'salt and pepper' manner, and are subsequently sorted into two distinct layers. Positional cues provided by the blastocyst cavity are thought to be instrumental for cell sorting; however, the sequence of events and the mechanisms that control this segregation remain unknown. Here, we show that atypical protein kinase C (aPKC), a protein associated with apicobasal polarity, is specifically enriched in PrE precursors in the ICM prior to cell sorting and prior to overt signs of cell polarisation. aPKC adopts a polarised localisation in PrE cells only after they reach the blastocyst cavity and form a mature epithelium, in a process that is dependent on FGF signalling. To assess the role of aPKC in PrE formation, we interfered with its activity using either chemical inhibition or RNAi knockdown. We show that inhibition of aPKC from the mid blastocyst stage not only prevents sorting of PrE precursors into a polarised monolayer but concomitantly affects the maturation of PrE precursors. Our results suggest that the processes of PrE and epiblast segregation, and cell fate progression are interdependent, and place aPKC as a central player in the segregation of epiblast and PrE progenitors in the mouse blastocyst.

  11. Endometrial glands are essential for blastocyst implantation and decidualization in the mouse uterus.

    PubMed

    Filant, Justyna; Spencer, Thomas E

    2013-04-01

    Uterine glands and their secretions are hypothesized to be essential for blastocyst implantation and decidualization in the uterus of rodents and humans. One factor solely expressed by uterine glands in mice is leukemia inhibitory factor (LIF), and Lif null mice are infertile because of defective blastocyst attachment to the uterine luminal epithelium (LE). Progesterone treatment of neonatal mice permanently ablates differentiation of uterine glands, resulting in an aglandular uterus in the adult. Progesterone-induced uterine gland knockout (PUGKO) mice were used to investigate the biological role of uterine glands in blastocyst implantation and stromal cell decidualization. As compared to controls, PUGKO mice cycled normally but were infertile. Histological assessment of PUGKO uteri on Days 5.5 and 8.5 postmating found a hatched blastocyst apposed to an intact LE without evidence of implantation or stromal cell decidualization. Expression of several implantation-related factors, including Lif and PTGS2, were altered in the PUGKO uterus, whereas expression of steroid hormone receptors and their regulated genes was not different. Artificial decidualization was observed in the uteri of control but not PUGKO mice. Further, intrauterine administration of LIF failed to promote artificial decidualization in the uterus of PUGKO mice. Thus, uterine glands and their secretions have important biological roles in blastocyst implantation and stromal cell decidualization in the uterus.

  12. Modulation of energy/electron transfer in gold nanoclusters by single walled carbon nanotubes and further consequences.

    PubMed

    Das, Tarasankar; Maity, Arnab; Mondal, Somen; Purkayastha, Pradipta

    2015-04-15

    Semiconductor or metallic character in single-walled carbon nanotubes (SWCNTs) is developed because of their chirality and diameter. Depending upon the extent of these characters in a particular sample of SWCNT, various electronic and mechanical applications are formulated. In this work we used protein protected red emitting gold nanoclusters (AuNCs) to enhance the metallic character in SWCNTs through electron transfer induced by photonic excitation. The AuNCs have been synthesized following a known protocol that generates Au(+) protected Au(0) clusters. Normal and carboxylic acid functionalized SWCNTs were obtained commercially for usage in the experiments. The non-functionalized SWCNTs facilitate intersystem electron transfer while the functionalized ones defer the phenomenon, which, in turn, affects the metallic character in the nanotubes. Steady state and time resolved fluorescence spectroscopy prove the dynamics and electrochemistry supports the intersystem electron transfer process.

  13. Modulation of energy/electron transfer in gold nanoclusters by single walled carbon nanotubes and further consequences

    NASA Astrophysics Data System (ADS)

    Das, Tarasankar; Maity, Arnab; Mondal, Somen; Purkayastha, Pradipta

    2015-04-01

    Semiconductor or metallic character in single-walled carbon nanotubes (SWCNTs) is developed because of their chirality and diameter. Depending upon the extent of these characters in a particular sample of SWCNT, various electronic and mechanical applications are formulated. In this work we used protein protected red emitting gold nanoclusters (AuNCs) to enhance the metallic character in SWCNTs through electron transfer induced by photonic excitation. The AuNCs have been synthesized following a known protocol that generates Au+ protected Au0 clusters. Normal and carboxylic acid functionalized SWCNTs were obtained commercially for usage in the experiments. The non-functionalized SWCNTs facilitate intersystem electron transfer while the functionalized ones defer the phenomenon, which, in turn, affects the metallic character in the nanotubes. Steady state and time resolved fluorescence spectroscopy prove the dynamics and electrochemistry supports the intersystem electron transfer process.

  14. Friction and metal transfer for single-crystal silicon carbide in contact with various metals in vacuum

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Buckley, D. H.

    1978-01-01

    Sliding friction experiments were conducted with single-crystal silicon carbide in contact with transition metals (tungsten, iron, rhodium, nickel, titanium, and cobalt), copper, and aluminum. Results indicate the coefficient of friction for a silicon carbide-metal system is related to the d bond character and relative chemical activity of the metal. The more active the metal, the higher the coefficient of friction. All the metals examined transferred to the surface of silicon carbide in sliding. The chemical activity of metal to silicon and carbon and shear modulus of the metal may play important roles in metal transfer and the form of the wear debris. The less active and greater resistance to shear the metal has, with the exception of rhodium and tungsten, the less transfer to silicon carbide.

  15. Lactate production by the mammalian blastocyst: manipulating the microenvironment for uterine implantation and invasion?

    PubMed

    Gardner, David K

    2015-04-01

    The mammalian blastocyst exhibits a high capacity for aerobic glycolysis, a metabolic characteristic of tumours. It has been considered that aerobic glycolysis is a means to ensure a high carbon flux to fulfil biosynthetic demands. Here, alternative explanations for this pattern of metabolism are considered. Lactate creates a microenvironment of low pH around the embryo to assist the disaggregation of uterine tissues to facilitate trophoblast invasion. Further it is proposed that lactate acts as a signalling molecule (especially at the reduced oxygen tension present at implantation) to elicit bioactive VEGF recruitment from uterine cells, to promote angiogenesis. Finally it is suggested that the region of high lactate/low pH created by the blastocyst modulates the activity of the local immune response, helping to create immune tolerance. Consequently, the mammalian blastocyst offers a model to study the role of microenvironments, and how metabolites and pH are used in signalling.

  16. A Two-Step Method for Transferring Single-Walled Carbon Nanotubes onto a Hydrogel Substrate.

    PubMed

    Imaninezhad, Mozhdeh; Kuljanishvili, Irma; Zustiak, Silviya Petrova

    2017-03-01

    Carbon nanotube (CNT)-hydrogel nanocomposites are beneficial for various biomedical applications, such as nerve regeneration, tissue engineering, sensing, or implant coatings. Still, there are impediments to developing nanocomposites, including attaining a homogeneous CNT-polymer dispersion or patterning CNTs on hydrogels. While few approaches have been reported for patterning CNTs on polymeric substrates, these methods include high temperature, high vacuum or utilize a sacrificial layer and, hence, are incompatible with hydrogels as they lead to irreversible collapse in hydrogel structure. In this study, a novel two-step method is designed to transfer CNTs onto hydrogels. First, dense CNTs are grown on quartz substrates. Subsequently, hydrogel solutions are deposited on the quartz-grown CNTs. Upon gelation, the hydrogel with transferred CNTs is peeled from the quartz. Successful transfer is confirmed by scanning electron microscopy and indirectly by cell attachment. The efficient transfer is attributed to π-interactions pregelation between the polymers in solution and the CNTs.

  17. Electronic Coupling Dependence of Ultrafast Interfacial Electron Transfer on Nanocrystalline Thin Films and Single Crystal

    SciTech Connect

    Lian, Tianquan

    2014-04-22

    The long-term goal of the proposed research is to understand electron transfer dynamics in nanoparticle/liquid interface. This knowledge is essential to many semiconductor nanoparticle based devices, including photocatalytic waste degradation and dye sensitized solar cells.

  18. Mothers, Workers and Students: Examining the Experiences of Single Mothers Transferring from Community Colleges into Universities

    ERIC Educational Resources Information Center

    Robinson, Emily Erin Peterson

    2010-01-01

    Single parent households are on the rise, and female headed households are more likely to live in poverty than other single parent households (Holyfield, 2002). Many single mothers who do not have an undergraduate degree see education as a way out of poverty (Holyfield, 2002; Heller & Bjorklund, 2004). This research was undertaken to highlight…

  19. Thermal visualization of heat-transfer characteristics for single impinging jet

    NASA Astrophysics Data System (ADS)

    Li, Liguo; Zhu, Yun; Zhang, Jingzhou; Yu, Wei

    The local heat-transfer characteristics of an impingement-cooling jet are presently ascertained, for cases with and without crossflow, through the use of a combined metal heating-element and cholesteric liquid crystal system. The results obtained indicate that the impingement Nusselt numbers of double-peak values increase with rising jet Reynolds number. A moving cylindrical jet-source model is used to simulate and analyze the jet's impingement heat transfer.

  20. Fate of tetraploid cells in 4n<-->2n chimeric mouse blastocysts.

    PubMed

    Mackay, Gillian E; West, John D

    2005-12-01

    Previous studies have shown that tetraploid (4n) cells rarely contribute to the derivatives of the epiblast lineage of mid-gestation 4n<-->2n mouse chimeras. The aim of the present study was to determine when and how 4n cells were excluded from the epiblast lineage of such chimeras. The contributions of GFP-positive cells to different tissues of 4n<-->2n chimeric blastocysts labelled with tauGFP were analysed at E3.5 and E4.5 using confocal microscopy. More advanced E5.5 and E7.5 chimeric blastocysts were analysed after a period of diapause to allow further growth without implantation. Tetraploid cells were not initially excluded from the epiblast in 4n<-->2n chimeric blastocysts and they contributed to all four blastocyst tissues at all of the blastocyst stages examined. Four steps affected the allocation and fate of 4n cells in chimeras, resulting in their exclusion from the epiblast lineage by mid-gestation. (1) Fewer 4n cells were allocated to the inner cell mass than trophectoderm. (2) The blastocyst cavity tended to form among the 4n cells, causing more 4n cells to be allocated to the hypoblast and mural trophectoderm than the epiblast and polar trophectoderm, respectively. (3) 4n cells were depleted from the hypoblast and mural trophectoderm, where initially they were relatively enriched. (4) After implantation 4n cells must be lost preferentially from the epiblast lineage. Relevance of these results to the aetiology of human confined placental mosaicism and possible implications for the interpretation of mouse tetraploid complementation studies of the site of gene action are discussed.

  1. Fibroblast growth factor 2 promotes primitive endoderm development in bovine blastocyst outgrowths.

    PubMed

    Yang, Qi En; Fields, Sarah D; Zhang, Kun; Ozawa, Manabu; Johnson, Sally E; Ealy, Alan D

    2011-11-01

    Primitive endoderm (PE) is the second extraembryonic tissue to form during embryogenesis in mammals. The PE develops from pluripotent cells of the blastocyst inner cell mass. Experimental results described herein provide evidence that FGF2 stimulates PE development during bovine blastocyst development in vitro. Bovine blastocysts were cultured individually on a feeder layer-free, Matrigel-coated surface in the presence or absence of FGF2. A majority of blastocysts cultures formed outgrowths (76.8%) and the rate of outgrowth formation was not affected by FGF2 supplementation. However, supplementation with FGF2 increased the incidence of PE outgrowths on Days 13 and 15 after in vitro fertilization. Presumptive PE cultures contained cells with a phenotype distinct from trophectoderm (TE). Cell identity was validated by expression of GATA4 and GATA6 mRNA and transferrin protein, all markers of the PE lineage. Expression of GATA4 occurred coincident with blastocyst expansion and hatching. These cells did not express IFNT and CDX2 (TE lineage markers). Profiles of FGF receptor (FGFR) isoforms were distinct between PE and TE cultures. Specifically, FGFR1b and FGFR1c were the predominant FGFR transcripts in PE whereas FGFR2b transcripts were abundant in TE. Supplementation with FGF2 increased the mitotic index of PE but not TE. Moreover, FGF signaling appears important for initiation of PE formation in blastocysts, presumably by lineage committal from NANOG-positive epiblast cells, because chemical disruption of FGFR kinase activity with PD173074 reduces GATA4 expression and increases NANOG expression. Collectively, these results indicate that FGF2 and potentially other FGFs specify PE formation and mediate PE proliferation during early pregnancy in cattle.

  2. Generation of parthenogenetic goat blastocysts: effects of different activation methods and culture media.

    PubMed

    Malik, Hruda Nanda; Singhal, Dinesh Kumar; Saugandhika, Shrabani; Dubey, Amit; Mukherjee, Ayan; Singhal, Raxita; Kumar, Sudarshan; Kaushik, Jai Kumar; Mohanty, Ashok Kumar; Das, Bikash Chandra; Bag, Sadhan; Bhanja, Subrata Kumar; Malakar, Dhruba

    2015-06-01

    The present study was carried out to investigate the effects of different activation methods and culture media on the in vitro development of parthenogenetic goat blastocysts. Calcium (Ca2+) ionophore, ethanol or a combination of the two, used as activating reagents, and embryo development medium (EDM), modified Charles Rosenkrans (mCR2a) medium and research vitro cleave (RVCL) medium were used to evaluate the developmental competence of goat blastocysts. Quantitative expression of apoptosis, stress and developmental competence-related genes were analysed in different stages of embryos. In RVCL medium, the cleavage rate of Ca2+ ionophore-treated oocytes (79.61 ± 0.86) was significantly (P < 0.05) higher than in ethanol (74.90 ± 1.51) or in the combination of both Ca2+ ionophore and ethanol. In mCR2a or EDM, hatched blastocyst production rate of Ca2+ ionophore-treated oocytes (8.33 ± 1.44) was significantly higher than in ethanol (6.46 ± 0.11) or in the combined treatment (6.70 ± 0.24). In ethanol, the cleavage, blastocyst and hatched blastocyst production rates in RVCL medium (74.90 ± 1.51, 18.30 ± 1.52 and 8.24 ± 0.15, respectively) were significantly higher than in EDM (67.81 ± 3.21, 14.59 ± 0.27 and 5.59 ± 0.42) or mCR2a medium (65.09 ± 1.57, 15.36 ± 0.52 and 6.46 ± 0.11). The expression of BAX, Oct-4 and GlUT1 transcripts increased gradually from 2-cell stage to blastocyst-stage embryos, whereas the transcript levels of Bcl-2 and MnSOD were significantly lower in blastocysts. In addition, different activation methods and culture media had little effect on the pattern of variation and relative abundance of the above genes in different stages of parthenogenetic activated goat embryos. In conclusion, Ca2+ ionophore as the activating agent, and RVCL as the culture medium are better than other tested options for development of parthenogenetic activated goat blastocysts.

  3. Regulation of gene expression in bovine blastocysts in response to oxygen and the iron chelator desferrioxamine.

    PubMed

    Harvey, A J; Kind, K L; Thompson, J G

    2007-07-01

    Low (2%) oxygen conditions during postcompaction culture of bovine blastocysts improve embryo quality and are associated with small increases in the expression of glucose transporter 1 (SLC2A1), anaphase promoting complex (ANAPC1), and myotrophin (MTPN), suggesting a role for oxygen in the regulation of embryo development, mediated through oxygen-sensitive gene expression. However, bovine embryos, to at least the blastocyst stage, lack detectable levels of the key regulator of oxygen-sensitive gene expression, hypoxia-inducible 1 alpha (HIF1A), while the less well-characterized HIF2 alpha protein is readily detectable. Here we report that other key HIF1 regulated genes are not significantly altered in their expression pattern in bovine blastocysts in response to reduced oxygen concentrations postcompaction-with the exception of lactate dehydrogenase A (LDHA), which was significantly increased following 2% oxygen culture. Antioxidant enzymes have been suggested as potential HIF2 target genes, but their expression was not altered following low-oxygen culture in the bovine blastocyst. The addition of desferrioxamine (an iron chelator and inducer of HIF-regulated gene expression) during postcompaction stages significantly increased SLC2A1, LDHA, inducible nitric oxide synthase (NOS2A), and MTPN gene expression in bovine blastocysts, although development to the blastocyst stage was not significantly affected. These results further suggest that expression of genes, known to be regulated by oxygen via HIF-1 in somatic cells, is not influenced by oxygen during preimplantation postcompaction bovine embryo development. Oxygen-regulated expression of LDHA and SLC2A1 in bovine blastocysts suggests that regulation of these genes may be mediated by HIF2. Furthermore, the effect of a reduced-oxygen environment on gene expression can be mimicked in vitro through the use of desferrioxamine. These results further support our data that the bovine blastocyst stage embryo is unique in

  4. Cloning of bovine embryos by multiple nuclear transfer.

    PubMed

    Takano, H; Kozai, C; Shimizu, S; Kato, Y; Tsunoda, Y

    1997-05-01

    The in vitro development of multiple generation bovine nuclear transferred embryos to blastocysts and their survival ability after freezing and thawing were examined. Parent donor embryos which had 20 to 50 cells were recovered from superovulated cows. Follicular oocytes matured in vitro were used as recipient oocytes. The recipient oocytes enucleated at 22 to 24 h after the onset of maturation were preactivated at 33 h. Enucleated oocytes with a donor blastomere were fused 9 h after activation by an electric stimulus and the fused oocytes were cultured in vitro (first generation). Reconstituted oocytes that had developed to the 8- to 16-cell stage 3 to 4 d after fusion were used as donor embryos for the next generation. Recloning procedures were performed twice (second and third generations). The proportion of recipient oocytes successfully fused with a blastomere increased with the cycle of nuclear transfer. Eighty to 86% of fused oocytes developed to the 2-cell stage and there was no significant difference with the generation. The proportion of reconstituted embryos receiving blastomeres derived from first generation embryos had higher developmental ability in vitro, than those derived from other generations (43 vs 31% for 8 to 16-cell stage, 37 vs 20 and 21% for blastocyst stage). The number of cloned blastocysts increased with repeated nuclear transfer (once: 6.2 +/- 4.3, twice: 19.8 +/- 9.2 and three times: 30.0 +/- 14.7) but varied greatly with each parent donor embryo. The in vitro viability of cloned blastocysts after freezing and thawing (59%) was low but not significantly different from that obtained for in vitro fertilized blastocysts (72%). After transfer of either fresh or frozen-thawed cloned blastocysts to 21 recipients, 10 of them were pregnant on Day 60. Four and 3 offspring were produced from 20 fresh and 14 frozen-thawed blastocysts,respectively.

  5. Quantum coherent energy transfer over varying pathways in single light-harvesting complexes.

    PubMed

    Hildner, Richard; Brinks, Daan; Nieder, Jana B; Cogdell, Richard J; van Hulst, Niek F

    2013-06-21

    The initial steps of photosynthesis comprise the absorption of sunlight by pigment-protein antenna complexes followed by rapid and highly efficient funneling of excitation energy to a reaction center. In these transport processes, signatures of unexpectedly long-lived coherences have emerged in two-dimensional ensemble spectra of various light-harvesting complexes. Here, we demonstrate ultrafast quantum coherent energy transfer within individual antenna complexes of a purple bacterium under physiological conditions. We find that quantum coherences between electronically coupled energy eigenstates persist at least 400 femtoseconds and that distinct energy-transfer pathways that change with time can be identified in each complex. Our data suggest that long-lived quantum coherence renders energy transfer in photosynthetic systems robust in the presence of disorder, which is a prerequisite for efficient light harvesting.

  6. DFT/B3LYP study of the substituent effect on the reaction enthalpies of the individual steps of single electron transfer-proton transfer and sequential proton loss electron transfer mechanisms of phenols antioxidant action.

    PubMed

    Klein, Erik; Lukes, Vladimír

    2006-11-09

    The reaction enthalpies related to the individual steps of two phenolic antioxidants action mechanisms, single electron transfer-proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET), for 30 meta and para-substituted phenols (ArOH) were calculated using DFT/B3LYP method. These mechanisms represent the alternative ways to the extensively studied hydrogen atom transfer (HAT) mechanism. Except the comparison of calculated reaction enthalpies with available experimental and/or theoretical values, obtained enthalpies were correlated with Hammett constants. We have found that electron-donating substituents induce the rise in the enthalpy of proton dissociation (PDE) from ArOH+* radical cation (second step in SET-PT) and in the proton affinities of phenoxide ions ArO- (reaction enthalpy of the first step in SPLET). Electron-withdrawing groups cause the increase in the reaction enthalpies of the processes where electron is abstracted, i.e., in the ionization potentials of ArOH (first step in SET-PT) and in the enthalpy of electron transfer from ArO- (second step in SPLET). Found results indicate that all dependences of reaction enthalpies on Hammett constants of the substituents are linear. The calculations of liquid-phase reaction enthalpies for several para-substituted phenols indicate that found trends hold also in water, although substituent effects are weaker. From the thermodynamic point of view, entering SPLET mechanism represents the most probable process in water.

  7. Experimental study of single-phase pressure drop and heat transfer in a micro-fin tube

    SciTech Connect

    Li, Xiao-Wei; Meng, Ji-An; Li, Zhi-Xin

    2007-11-15

    The single-phase pressure drop and heat transfer in a micro-fin tube were measured using oil and water as the working fluids. The Prandtl number varied from 3.2 to 220 and the Reynolds number ranged from 2500 to 90,000. The results show that there is a critical Reynolds number, Re{sub cr}, for heat transfer enhancement. For Retransfer in the micro-fin tube is the same as that in a smooth tube, but for Reynolds numbers higher than Re{sub cr}, the heat transfer in the micro-fin tube is gradually enhanced compared with a smooth tube. It reaches more than twice that in a smooth tube for Reynolds numbers greater than 30,000 with water as the working fluid. The Nusselt number is proportional to Pr {sup 0.56} in the enhanced region and is proportional to Pr {sup 0.3} in the non-enhanced region. For the high Prandtl number working fluid (oil, 80< Pr <220), the critical Reynolds number for heat transfer enhancement is about 6000, while for the low Prandtl number working fluid (water, 3.2< Pr <5.8), the critical Reynolds number for heat transfer enhancement is about 10,000. The friction factors in the micro-fin tube are almost the same as for a smooth tube for Reynolds numbers below 10,000. For Reynolds numbers higher than 30,000, the friction factor is about 40-50% higher than for a smooth tube. (author)

  8. IGF-1/IGFBP-1 increases blastocyst formation and total blastocyst cell number in mouse embryo culture and facilitates the establishment of a stem-cell line

    PubMed Central

    Lin, Ta-Chin; Yen, Jui-Mei; Gong, Kun-Bing; Hsu, Teng-Tsao; Chen, Lih-Ren

    2003-01-01

    Background Apoptosis occurs frequently for blastocysts cultured in vitro, where conditions are suboptimal to those found in the natural environment. Insulin-like growth factor-1 (IGF-1) plays an important role in preventing apoptosis in the early development of the embryo, as well as in the progressive regulation of organ development. We hypothesize that IGF-1 and its dephosphorylated binding protein (IGFBP-1) may be able to improve embryo culture with an associated reduced cell death, and that the resultant increase in the total cell number of the embryo could increase the chances of establishing an embryonic stem-cell line. Results In vivo fertilized zygotes were cultured in medium containing supplementary IGF-1, or IGFBP-1/IGF-1. The stages of the resultant embryos were evaluated at noon on day five post-hCG injection. The extent of apoptosis and necrosis was evaluated using Annexin V and propidium iodine staining under fluorescent microscopy. The establishment of embryonic stem-cell lines was performed using the hatching blastocysts that were cultured in the presence of IGF-1 or IGFBP-1/IGF-1. The results show that the rate of blastocyst formation in a tissue-culture system in the presence of IGF-1 was 88.7% and IGFBP-1/IGF-1 it was 94.6%, respectively, and that it was significantly greater than the figure for the control group (81.9%). IGFBP-1/IGF-1 also resulted in a higher hatching rate than was the case for the control group (68.8% vs. 48.6% respectively). IGF-1 also increased the number of Annexin V-free and propidium iodine-free blastocysts in culture (86.8% vs. 75.9% respectively). Total cell number of blastocyst in culture was increased by 18.9% for those examples cultured with dephosphorylated IGFBP-1/IGF-1. For subsequent stem-cell culture, the chances of the successful establishment of a stem-cell line was increased for the IGF-1 and IGFBP-1/IGF-1 groups (IGF-1 vs. IGFBP-1/IGF-1 vs. control: 45.8% vs. 59.6% vs. 27.3% respectively). Conclusion IGF-1

  9. Prosurvival effect of cumulus prostaglandin G/H synthase 2/prostaglandin2 signaling on bovine blastocyst: impact on in vivo posthatching development†.

    PubMed

    Nuttinck, Fabienne; Jouneau, Alice; Charpigny, Gilles; Hue, Isabelle; Richard, Christophe; Adenot, Pierre; Ruffini, Sylvie; Laffont, Ludivine; Chebrout, Martine; Duranthon, Véronique; Guienne, Brigitte Marquant-Le

    2017-03-07

    Apoptotic activity is a common physiological process which culminates at the blastocyst stage in the preimplantation embryo of many mammals. The degree of embryonic cell death can be influenced by the oocyte microenvironment. However, the prognostic significance of the incidence of apoptosis remains undefined. Prostaglandin E2 (PGE2) derived from prostaglandin G/H synthase-2 (PTGS2) activity is a well-known prosurvival factor that is mainly studied in oncology. PGE2 is the predominant PTGS2-derived prostaglandin present in the oocyte microenvironment during the periconceptional period. Using an in vitro model of bovine embryo production followed by transfer and collection procedures, we investigated the impact of periconceptional PGE2 on the occurrence of spontaneous apoptosis in embryos and on subsequent in vivo posthatching development. Different periconceptional PGE2 environments were obtained using NS-398, a specific inhibitor of PTGS2 activity, and exogenous PGE2. We assessed the level of embryonic cell death in blastocysts at day 8 postfertilization by counting total cell numbers, by the immunohistochemical staining of active caspase-3, and by quantifying terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling signals and apoptosis regulator (BCL-2/BAX) mRNA expression. Morphometric parameters were used to estimate the developmental stage of the embryonic disk and the extent of trophoblast elongation on day 15 conceptuses. Our findings indicate that periconceptional PGE2 signaling durably impacts oocytes, conferring increased resistance to spontaneous apoptosis in blastocysts and promoting embryonic disk development and the elongation process during preimplantation development.

  10. Cross-beam energy transfer to a single f-20 beam: simulations of previous and upcoming experiments

    NASA Astrophysics Data System (ADS)

    Chapman, Thomas; Turnbull, David; Kirkwood, Robert; Michel, Pierre; Wilks, Scott; Berger, Richard; Hinkel, Denise; Moody, John; Langer, Steve; Langdon, Bruce; Strozzi, David

    2016-10-01

    Motivated by materials research applications, cross-beam energy transfer can be used to transfer energy from one or more quads of beamlets at the NIF, which have an effective f-number of 8, to a single f-20 beam. Using plasma comprised of a preheated C5H12 gasbag, a preliminary experiment at the NIF demonstrated amplification of a 750 J f-20 beam by a factor of 2 in both power and energy. A witness plate providing gated x-ray images was used to obtain total energies and transmitted spot intensities for the pump quad, seed beamlet, and a calibration quad. These experimental diagnostics offer the opportunity to perform quantitative comparisons with simulations. We use the laser-plasma interaction code pF3D to simulate the energy transfer process, using plasma conditions obtained from the plasma hydrodynamics code HYDRA. Our simulations of the completed single-pump quad experiment recover the measured seed amplification and transmitted spot power distributions. We also show simulation results for the upcoming two-pump quad experiment.

  11. Multiple LHCII antennae can transfer energy efficiently to a single Photosystem I.

    PubMed

    Bos, Inge; Bland, Kaitlyn M; Tian, Lijin; Croce, Roberta; Frankel, Laurie K; van Amerongen, Herbert; Bricker, Terry M; Wientjes, Emilie

    2017-02-22

    Photosystems I and II (PSI and PSII) work in series to drive oxygenic photosynthesis. The two photosystems have different absorption spectra, therefore changes in light quality can lead to imbalanced excitation of the photosystems and a loss in photosynthetic efficiency. In a short-term adaptation response termed state transitions, excitation energy is directed to the light-limited photosystem. In higher plants a special pool of LHCII antennae, which can be associated with either PSI or PSII, participates in these state transitions. It is known that one LHCII antenna can associate with the PsaH site of PSI. However, membrane fractions were recently isolated in which multiple LHCII antennae appear to transfer energy to PSI. We have used time-resolved fluorescence-streak camera measurements to investigate the energy transfer rates and efficiency in these membrane fractions. Our data show that energy transfer from LHCII to PSI is relatively slow. Nevertheless, the trapping efficiency in supercomplexes of PSI with ~2.4 LHCIIs attached is 94%. The absorption cross section of PSI can thus be increased with ~65% without having significant loss in quantum efficiency. Comparison of the fluorescence dynamics of PSI-LHCII complexes, isolated in a detergent or located in their native membrane environment, indicates that the environment influences the excitation energy transfer rates in these complexes. This demonstrates the importance of studying membrane protein complexes in their natural environment.

  12. Impact of blastocyst biopsy and comprehensive chromosome screening technology on preimplantation genetic screening: a systematic review of randomized controlled trials.

    PubMed

    Dahdouh, Elias M; Balayla, Jacques; García-Velasco, Juan Antonio

    2015-03-01

    Embryonic aneuploidy is highly prevalent in IVF cycles and contributes to decreased implantation rates, IVF cycle failure and early pregnancy loss. Preimplantation genetic screening (PGS) selects the most competent (euploid) embryos for transfer, and has been proposed to improve IVF outcomes. Use of PGS with fluorescence-in-situ hybridization technology after day 3 embryo biopsy (PGS-v1) significantly lowers live birth rates and is not recommended for use. Comprehensive chromosome screening technology, which assesses the whole chromosome complement, can be achieved using different genetic platforms. Whether PGS using comprehensive chromosome screening after blastocyst biopsy (PGS-v2) improves IVF outcomes remains to be determined. A systematic review of randomized controlled trials was conducted on PGS-v2. Three trials met full inclusion criteria, comparing PGS-v2 and routine IVF care. PGS-v2 is associated with higher clinical implantation rates, and higher ongoing pregnancy rates when the same number of embryos is transferred in both PGS and control groups. Additionally, PGS-v2 improves embryo selection in eSET practice, maintaining the same ongoing pregnancy rates between PGS and control groups, while sharply decreasing multiple pregnancy rates. These results stem from good-prognosis patients undergoing IVF. Whether these findings can be extrapolated to poor-prognosis patients with decreased ovarian reserve remains to be determined.

  13. High-fin staggered tube banks: Heat transfer and pressure drop for turbulent single phase gas flow

    NASA Astrophysics Data System (ADS)

    1986-10-01

    This Data Item ESDU 86022 is an addition to the Heat Transfer Sub-series. New correlations are presented for external heat transfer coefficient and static pressure loss for single phase flow over plain circular fins of either retangular or tapered cross section on round tubes. The correlations were derived by a regression analysis of experimental results extracted from the literature for a wide range of tube bundle configurations. Fin densities of 4 to 11 per inch (equivalent to fin pitches of 6.4 to 2.3 mm) tube outside diameters of 3/8 to 2 inch (10 to 51 mm), fin heights of 1/4 to 5/8 inch (6 to 16 mm), and ratios of fin tip to fin root diameter of 1.2 to 2.4 were covered. For heat transfer the range of Reynolds number based on tube outer diameter was from 2,000 to 40,000 and for pressure drop from 5,000 to 50,000. Comparison of the prediction with experiment shows that for heat transfer 85% of the data points were within 10% of estimated and for pressure drop 72% were within 10%. A comprehensive worked example showing the use of the method for an air cooled heat exchanger bundle is included. The applicability of this method to nonintegral fins is considered and factors influencing the thermal resistance of the interface are discussed. Effects of fouling are also briefly covered.

  14. Uterine glands impact uterine receptivity, luminal fluid homeostasis and blastocyst implantation

    PubMed Central

    Kelleher, Andrew M.; Burns, Gregory W.; Behura, Susanta; Wu, Guoyao; Spencer, Thomas E.

    2016-01-01

    Uterine glands are essential for pregnancy in mice and likely humans, because they secrete or transport bioactive substances that regulate uterine receptivity for blastocyst implantation. In mice, the uterus becomes receptive to blastocyst implantation on day 4, but is refractory by day 5. Here, blastocysts could be recovered from progesterone-induced uterine gland (PUGKO) but not wildtype (WT) mice on day 5 post-mating. Anti-adhesive Muc1 protein and microvilli were present on the luminal epithelium of PUGKO but not WT uteri. A number of known uterine receptivity genes and gland-specific genes were altered in the PUGKO uterus. Next, the uterus and uterine luminal fluid (ULF) were obtained from WT and PUGKO mice on day 3, 4 and 5. Transcriptome analysis revealed that 580 genes were decreased in the PUGKO uterus, however ULF secrotome analysis revealed that many proteins and several amino acids were increased in the PUGKO ULF. Of note, many proteins encoded by many gland-specific genes were not identified in the ULF of WT mice. These results support the ideas that uterine glands secrete factors that regulate ULF homeostasis and interact with other cell types in the uterus to influence uterine receptivity and blastocyst implantation for the establishment of pregnancy. PMID:27905495

  15. Stress exposure during the preimplantation period affects blastocyst lineages and offspring development

    PubMed Central

    BURKUŠ, Ján; KAČMAROVÁ, Martina; KUBANDOVÁ, Janka; KOKOŠOVÁ, Natália; FABIANOVÁ, Kamila; FABIAN, Dušan; KOPPEL, Juraj; ČIKOŠ, Štefan

    2015-01-01

    We found retardation of preimplantation embryo growth after exposure to maternal restraint stress during the preimplantation period in our previous study. In the present study, we evaluated the impact of preimplantation maternal restraint stress on the distribution of inner cell mass (ICM) and trophectoderm (TE) cells in mouse blastocysts, and its possible effect on physiological development of offspring. We exposed spontaneously ovulating female mice to restraint stress for 30 min three times a day during the preimplantation period, and this treatment caused a significant increase in blood serum corticosterone concentration. Microscopic evaluation of embryos showed that restraint stress significantly decreased cell counts per blastocyst. Comparing the effect of restraint stress on the two blastocyst cell lineages, we found that the reduction in TE cells was more substantial than the reduction in ICM cells, which resulted in an increased ICM/TE ratio in blastocysts isolated from stressed dams compared with controls. Restraint stress reduced the number of implantation sites in uteri, significantly delayed eye opening in delivered mice, and altered their behavior in terms of two parameters (scratching on the base of an open field test apparatus, time spent in central zone) as well. Moreover, prenatally stressed offspring had significantly lower body weights and in 5-week old females delivered from stressed dams, fat deposits were significantly lower. Our results indicate that exposure to stress during very early pregnancy can have a negative impact on embryonic development with consequences reaching into postnatal life. PMID:25985793

  16. Distinct mechanisms regulate Cdx2 expression in the blastocyst and in trophoblast stem cells.

    PubMed

    Rayon, Teresa; Menchero, Sergio; Rollán, Isabel; Ors, Inmaculada; Helness, Anne; Crespo, Miguel; Nieto, Andres; Azuara, Véronique; Rossant, Janet; Manzanares, Miguel

    2016-06-03

    The first intercellular differences during mammalian embryogenesis arise in the blastocyst, producing the inner cell mass and the trophectoderm. The trophectoderm is the first extraembryonic tissue and does not contribute to the embryo proper, its differentiation instead forming tissues that sustain embryonic development. Crucial roles in extraembryonic differentiation have been identified for certain transcription factors, but a comprehensive picture of the regulation of this early specification is still lacking. Here, we investigated whether the regulatory mechanisms involved in Cdx2 expression in the blastocyst are also utilized in the postimplantation embryo. We analyzed an enhancer that is regulated through Hippo and Notch in the blastocyst trophectoderm, unexpectedly finding that it is inactive in the extraembryonic structures at postimplantation stages. Further analysis identified other Cdx2 regulatory elements including a stem-cell specific regulatory sequence and an element that drives reporter expression in the trophectoderm, a subset of cells in the extraembryonic region of the postimplantation embryo and in trophoblast stem cells. The cross-comparison in this study of cis-regulatory elements employed in the blastocyst, stem cell populations and the postimplantation embryo provides new insights into early mammalian development and suggests a two-step mechanism in Cdx2 regulation.

  17. Overexpression of OCT4A ortholog elevates endogenous XIST in porcine parthenogenic blastocysts

    PubMed Central

    HWANG, Jae Yeon; CHOI, Kwang-Hwan; LEE, Dong-Kyung; KIM, Seung-Hun; KIM, Eun Bae; HYUN, Sang-Hwan; LEE, Chang-Kyu

    2015-01-01

    X-chromosome inactivation (XCI) is an epigenetic process that equalizes expression of X-borne genes between male and female eutherians. This process is observed in early eutherian embryo development in a species-specific manner. Until recently, various pluripotent factors have been suggested to regulate the process of XCI by repressing XIST expression, which is the master inducer for XCI. Recent insights into the process and its regulation have been restricted in mouse species despite the evolutionary diversity of the process and molecular mechanism among the species. OCT4A is one of the represented pluripotent factors, the gate-keeper for maintaining pluripotency, and an XIST repressor. Therefore, in here, we examined the relation between OCT4A and X-linked genes in porcine preimplantation embryos. Three X-linked genes, XIST, LOC102165544, and RLIM, were selected in present study because their orthologues have been known to regulate XCI in mice. Expression levels of OCT4A were positively correlated with XIST and LOC102165544 in female blastocysts. Furthermore, overexpression of exogenous human OCT4A in cleaved parthenotes generated blastocysts with increased XIST expression levels. However, increased XIST expression was not observed when exogenous OCT4A was obtained from early blastocysts. These results suggest the possibility that OCT4A would be directly or indirectly involved in XIST expression in earlier stage porcine embryos rather than blastocysts. PMID:26255835

  18. Distinct mechanisms regulate Cdx2 expression in the blastocyst and in trophoblast stem cells

    PubMed Central

    Rayon, Teresa; Menchero, Sergio; Rollán, Isabel; Ors, Inmaculada; Helness, Anne; Crespo, Miguel; Nieto, Andres; Azuara, Véronique; Rossant, Janet; Manzanares, Miguel

    2016-01-01

    The first intercellular differences during mammalian embryogenesis arise in the blastocyst, producing the inner cell mass and the trophectoderm. The trophectoderm is the first extraembryonic tissue and does not contribute to the embryo proper, its differentiation instead forming tissues that sustain embryonic development. Crucial roles in extraembryonic differentiation have been identified for certain transcription factors, but a comprehensive picture of the regulation of this early specification is still lacking. Here, we investigated whether the regulatory mechanisms involved in Cdx2 expression in the blastocyst are also utilized in the postimplantation embryo. We analyzed an enhancer that is regulated through Hippo and Notch in the blastocyst trophectoderm, unexpectedly finding that it is inactive in the extraembryonic structures at postimplantation stages. Further analysis identified other Cdx2 regulatory elements including a stem-cell specific regulatory sequence and an element that drives reporter expression in the trophectoderm, a subset of cells in the extraembryonic region of the postimplantation embryo and in trophoblast stem cells. The cross-comparison in this study of cis-regulatory elements employed in the blastocyst, stem cell populations and the postimplantation embryo provides new insights into early mammalian development and suggests a two-step mechanism in Cdx2 regulation. PMID:27256674

  19. Effect of L-carnitine on in vitro developmental rate, the zona pellucida and hatching of blastocysts and their cell numbers in mouse embryos

    PubMed Central

    Khanmohammadi, Nasrin; Movahedin, Mansoureh; Safari, Manouchehr; Sameni, Hamid Reza; Yousefi, Behpour; Jafari, Behnaz; Zarbakhsh, Sam

    2016-01-01

    L-carnitine (LC) is an antioxidant with the ability to promote the growth in vitro embryo. Objective: The goal was to evaluate the effect of LC on some indicators of embryo development and blastocyst quality including zona pellucid (ZP) thickness, the hatching of blastocysts and their cell numbers. Materials and Methods: Mouse embryos were randomly divided into five groups and incubated with different concentrations of LC (I; 0, II; 0.5, III; 1, IV; 2 and V; 4 mg/ml) from 2-cell to hatched blastocyst. The percentage of blastocysts and hatched blastocysts was calculated. Blastocysts ZP thickness was measured and the number of blastocyst cells was counted using Hoechst and propidium iodide (PI) staining. Results: The results showed concentration of 0.5 mg/ml of LC had an antioxidant effect as in this group, the percentage of blastocysts and hatched blactocysts (p=0.01), the ZP thickness (p=0.00) and the number of blastocyst inner cell mass were significantly more favorable than the control group (p=0.03); and concentration of 4 mg/ml of LC had a toxic effect on embryo development and blastocyst quality (p=0.00). Conclusion: The results suggest that LC may increase the number of blastocyst cells, which probably helps to expand the blastocyst and thinning of the ZP thickness and, therefore, creating a successful hatching for implantation. PMID:27921089

  20. Probing electron transfer mechanisms in Shewanella oneidensis MR-1 using a nanoelectrode platform and single-cell imaging.

    PubMed

    Jiang, Xiaocheng; Hu, Jinsong; Fitzgerald, Lisa A; Biffinger, Justin C; Xie, Ping; Ringeisen, Bradley R; Lieber, Charles M

    2010-09-28

    Microbial fuel cells (MFCs) represent a promising approach for sustainable energy production as they generate electricity directly from metabolism of organic substrates without the need for catalysts. However, the mechanisms of electron transfer between microbes and electrodes, which could ultimately limit power extraction, remain controversial. Here we demonstrate optically transparent nanoelectrodes as a platform to investigate extracellular electron transfer in Shewanella oneidensis MR-1, where an array of nanoholes precludes or single window allows for direct microbe-electrode contacts. Following addition of cells, short-circuit current measurements showed similar amplitude and temporal response for both electrode configurations, while in situ optical imaging demonstrates that the measured currents were uncorrelated with the cell number on the electrodes. High-resolution imaging showed the presence of thin, 4- to 5-nm diameter filaments emanating from cell bodies, although these filaments do not appear correlated with current generation. Both types of electrodes yielded similar currents at longer times in dense cell layers and exhibited a rapid drop in current upon removal of diffusible mediators. Reintroduction of the original cell-free media yielded a rapid increase in current to ∼80% of original level, whereas imaging showed that the positions of > 70% of cells remained unchanged during solution exchange. Together, these measurements show that electron transfer occurs predominantly by mediated mechanism in this model system. Last, simultaneous measurements of current and cell positions showed that cell motility and electron transfer were inversely correlated. The ability to control and image cell/electrode interactions down to the single-cell level provide a powerful approach for advancing our fundamental understanding of MFCs.

  1. Epigenetic differences between male and female bovine blastocysts produced in vitro.

    PubMed

    Bermejo-Alvarez, P; Rizos, D; Rath, D; Lonergan, P; Gutierrez-Adan, A

    2008-01-17

    Epigenetic differences between male and female bovine blastocysts provide a plausible link between physiological and gene transcription differences observed between male and female embryos. The aim of this study was to examine sex-related epigenetic differences in bovine blastocysts produced in vitro. Oocytes were matured in vitro and inseminated with frozen-thawed sex-sorted (X or Y) and unsorted (control) bull sperm. Zygotes were cultured to blastocyst stage and were analyzed for embryo sexing, mtDNA content, telomere lengths, methylation analysis, and quantification of mRNA transcripts of DNA methyltransferases (Dnmt1, Dnmt3a, Dnmt3b) HMT1 hnRNP methyltransferase-like 2 (Hmt1), and interleukin enhancer binding factor 3 (Ilf3). There was a difference (P < 0.05) in the mean mtDNA copy number between male (410,000 +/- 23,000) and female (360,000 +/- 21,000) blastocysts. Telomere length was shorter in male blastocysts (P < 0.01). The level of methylation in a sequence near a variable number of tandem repeats minisatellite region [variable number of tandem repeats (VNTR)] in males (39.8% +/- 4.8) was higher than in females (23.7% +/- 3.1) (P < 0.05); however, no differences were found in other regions analyzed. Moreover, transcription differences between sexes were observed for Dnmt3a, Dnmt3b, Hmt1, and Ilf3. These results provide evidence of epigenetic differences between male and female bovine in vitro produced embryos and suggest that before initiation of gonadal differentiation, epigenetic events may modulate the difference between speed of development, metabolism, and transcription observed during preimplantation development between male and female embryos.

  2. Messenger RNAs in metaphase II oocytes correlate with successful embryo development to the blastocyst stage.

    PubMed

    Biase, Fernando Henrique; Everts, Robin Edward; Oliveira, Rosane; Santos-Biase, Weruska Karyna Freitas; Fonseca Merighe, Giovana Krempel; Smith, Lawrence Charles; Martelli, Lúcia; Lewin, Harris; Meirelles, Flávio Vieira

    2014-02-01

    The mRNAs accumulated in oocytes provide support for embryo development until embryo genomic activation. We hypothesized that the maternal mRNA stock present in bovine oocytes is associated with embryo development until the blastocyst stage. To test our hypothesis, we analyzed the transcriptome of the oocyte and correlated the results with the embryo development. Our goal was to identify genes expressed in the oocyte that correlate with its ability to develop to the blastocyst stage. A fraction of oocyte cytoplasm was biopsied using micro-aspiration and stored for further expression analysis. Oocytes were activated chemically, cultured individually and classified according to their capacity to develop in vitro to the blastocyst stage. Microarray analysis was performed on mRNA extracted from the oocyte cytoplasm fractions and correlated with its ability to develop to the blastocyst stage (good quality oocyte) or arrest at the 8-16-cell stage (bad quality oocyte). The expression of 4320 annotated genes was detected in the fractions of cytoplasm that had been collected from oocytes matured in vitro. Gene ontology classification revealed that enriched gene expression of genes was associated with certain biological processes: 'RNA processing', 'translation' and 'mRNA metabolic process'. Genes that are important to the molecular functions of 'RNA binding' and 'translation factor activity, RNA binding' were also enriched in oocytes. We identified 29 genes with differential expression between the two groups of oocytes compared (good versus bad quality). The content of mRNAs expressed in metaphase II oocytes influences the activation of the embryonic genome and enables further develop to the blastocyst stage.

  3. The spatiotemporal hormonal orchestration of human folliculogenesis, early embryogenesis and blastocyst implantation.

    PubMed

    Atwood, Craig S; Vadakkadath Meethal, Sivan

    2016-07-15

    The early reproductive events starting with folliculogenesis and ending with blastocyst implantation into the uterine endometrium are regulated by a complex interplay among endocrine, paracrine and autocrine factors. This review examines the spatiotemporal integration of these maternal and embryonic signals that are required for successful reproduction. In coordination with hypothalamic-pituitary-gonadal (HPG) hormones, an intraovarian HPG-like axis regulates folliculogenesis, follicular quiescence, ovulation, follicular atresia, and corpus luteal functions. Upon conception and passage of the zygote through the fallopian tube, the contribution of maternal hormones in the form of paracrine secretions from the endosalpinx to embryonic development declines, with autocrine and paracrine signaling becoming increasingly important as instructional signals for the differentiation of the early zygote/morula into a blastocyst. These maternal and embryonic signals include activin and gonadotropin-releasing hormone 1 (GnRH1) that are crucial for the synthesis and secretion of the 'pregnancy' hormone human chorionic gonadotropin (hCG). hCG in turn signals pre-implantation embryonic cell division and sex steroid production required for stem cell differentiation, and subsequent blastulation, gastrulation, cavitation and blastocyst formation. Upon reaching the uterus, blastocyst hatching occurs under the influence of decreased activin signaling, while the attachment and invasion of the trophoblast into the endometrium appears to be driven by a decrease in activin signaling, and by increased GnRH1 and hCG signaling that allows for tissue remodeling and the controlled invasion of the blastocyst into the uterine endometrium. This review demonstrates the importance of integrative endocrine, paracrine, and autocrine signaling for successful human reproduction.

  4. Epidermal growth factor improves developmental competence and embryonic quality of singly cultured domestic cat embryos

    PubMed Central

    THONGKITTIDILOK, Chommanart; THARASANIT, Theerawat; SONGSASEN, Nucharin; SANANMUANG, Thanida; BUARPUNG, Sirirak; TECHAKUMPHU, Mongkol

    2015-01-01

    This study examined the influence of EGF on the expression of EGF receptors (EGFR) and developmental competence of embryos cultured individually versus those cultured in groups. Cat oocytes were in vitro matured and fertilized (IVM/IVF), and cleaved embryos were randomly assigned to one of seven culture conditions: one group each in which embryos were subjected to group culture supplemented with or without 5 ng/ml EGF and five groups in which embryos were subjected to single-embryo culture supplemented with EGF (0, 5, 25, 50 or 100 ng/ml). Morulae, blastocysts and hatching blastocysts were assessed at days 5 and 7; post IVF, respectively, and total blastocyst cell numbers were assessed at day 7. Relative mRNA expressions of EGFR of 2–4-cell embryos, 8–16-cell embryos, morulae and blastocysts cultured in groups or singly with or without EGF supplementation were examined. OCT3/4 and Ki67 in blastocysts derived from the group or single-embryo culture systems with or without EGF supplementation were localized. A higher rate of embryos cultured in groups developed to blastocysts than individually incubated cohorts. Although EGF increased blastocyst formation in the single-embryo culture system, EGF did not affect embryo development in group culture. Expression levels of EGFR decreased in morulae and blastocysts cultured with EGF. An increased ratio of Ki67-positive cells to the total number of cells in the blastocyst was observed in singly cultured embryos in the presence of EGF. However, EGF did not affect the expression of OCT3/4. These findings indicate that EGF enhanced developmental competence of cat embryos cultured singly by stimulating cell proliferation and modulating the EGFR expression at various developmental stages. PMID:25985792

  5. Epidermal growth factor improves developmental competence and embryonic quality of singly cultured domestic cat embryos.

    PubMed

    Thongkittidilok, Chommanart; Tharasanit, Theerawat; Songsasen, Nucharin; Sananmuang, Thanida; Buarpung, Sirirak; Techakumphu, Mongkol

    2015-01-01

    This study examined the influence of EGF on the expression of EGF receptors (EGFR) and developmental competence of embryos cultured individually versus those cultured in groups. Cat oocytes were in vitro matured and fertilized (IVM/IVF), and cleaved embryos were randomly assigned to one of seven culture conditions: one group each in which embryos were subjected to group culture supplemented with or without 5 ng/ml EGF and five groups in which embryos were subjected to single-embryo culture supplemented with EGF (0, 5, 25, 50 or 100 ng/ml). Morulae, blastocysts and hatching blastocysts were assessed at days 5 and 7; post IVF, respectively, and total blastocyst cell numbers were assessed at day 7. Relative mRNA expressions of EGFR of 2-4-cell embryos, 8-16-cell embryos, morulae and blastocysts cultured in groups or singly with or without EGF supplementation were examined. OCT3/4 and Ki67 in blastocysts derived from the group or single-embryo culture systems with or without EGF supplementation were localized. A higher rate of embryos cultured in groups developed to blastocysts than individually incubated cohorts. Although EGF increased blastocyst formation in the single-embryo culture system, EGF did not affect embryo development in group culture. Expression levels of EGFR decreased in morulae and blastocysts cultured with EGF. An increased ratio of Ki67-positive cells to the total number of cells in the blastocyst was observed in singly cultured embryos in the presence of EGF. However, EGF did not affect the expression of OCT3/4. These findings indicate that EGF enhanced developmental competence of cat embryos cultured singly by stimulating cell proliferation and modulating the EGFR expression at various developmental stages.

  6. Single-stage Dynamic Reanimation of the Smile in Irreversible Facial Paralysis by Free Functional Muscle Transfer

    PubMed Central

    Thiele, Jan; Bannasch, Holger; Stark, G. Bjoern; Eisenhardt, Steffen U.

    2015-01-01

    Unilateral facial paralysis is a common disease that is associated with significant functional, aesthetic and psychological issues. Though idiopathic facial paralysis (Bell’s palsy) is the most common diagnosis, patients can also present with a history of physical trauma, infectious disease, tumor, or iatrogenic facial paralysis. Early repair within one year of injury can be achieved by direct nerve repair, cross-face nerve grafting or regional nerve transfer. It is due to muscle atrophy that in long lasting facial paralysis complex reconstructive methods have to be applied. Instead of one single procedure, different surgical approaches have to be considered to alleviate the various components of the paralysis. The reconstruction of a spontaneous dynamic smile with a symmetric resting tone is a crucial factor to overcome the functional deficits and the social handicap that are associated with facial paralysis. Although numerous surgical techniques have been described, a two-stage approach with an initial cross-facial nerve grafting followed by a free functional muscle transfer is most frequently applied. In selected patients however, a single-stage reconstruction using the motor nerve to the masseter as donor nerve is superior to a two-stage repair. The gracilis muscle is most commonly used for reconstruction, as it presents with a constant anatomy, a simple dissection and minimal donor site morbidity. Here we demonstrate the pre-operative work-up, the post-operative management, and precisely describe the surgical procedure of single-stage microsurgical reconstruction of the smile by free functional gracilis muscle transfer in a step by step protocol. We further illustrate common pitfalls and provide useful tips which should enable the reader to truly comprehend the procedure. We further discuss indications and limitations of the technique and demonstrate representative results. PMID:25868011

  7. Single-stage dynamic reanimation of the smile in irreversible facial paralysis by free functional muscle transfer.

    PubMed

    Thiele, Jan; Bannasch, Holger; Stark, G Bjoern; Eisenhardt, Steffen U

    2015-03-01

    Unilateral facial paralysis is a common disease that is associated with significant functional, aesthetic and psychological issues. Though idiopathic facial paralysis (Bell's palsy) is the most common diagnosis, patients can also present with a history of physical trauma, infectious disease, tumor, or iatrogenic facial paralysis. Early repair within one year of injury can be achieved by direct nerve repair, cross-face nerve grafting or regional nerve transfer. It is due to muscle atrophy that in long lasting facial paralysis complex reconstructive methods have to be applied. Instead of one single procedure, different surgical approaches have to be considered to alleviate the various components of the paralysis. The reconstruction of a spontaneous dynamic smile with a symmetric resting tone is a crucial factor to overcome the functional deficits and the social handicap that are associated with facial paralysis. Although numerous surgical techniques have been described, a two-stage approach with an initial cross-facial nerve grafting followed by a free functional muscle transfer is most frequently applied. In selected patients however, a single-stage reconstruction using the motor nerve to the masseter as donor nerve is superior to a two-stage repair. The gracilis muscle is most commonly used for reconstruction, as it presents with a constant anatomy, a simple dissection and minimal donor site morbidity. Here we demonstrate the pre-operative work-up, the post-operative management, and precisely describe the surgical procedure of single-stage microsurgical reconstruction of the smile by free functional gracilis muscle transfer in a step by step protocol. We further illustrate common pitfalls and provide useful tips which should enable the reader to truly comprehend the procedure. We further discuss indications and limitations of the technique and demonstrate representative results.

  8. Guanine radical reaction processes: a computational description of proton transfer in X-irradiated 9-ethylguanine single crystals.

    PubMed

    Jayatilaka, Nayana; Nelson, William H

    2008-12-25

    Computational methods based on DFT procedures have been used to investigate proton-transfer processes in irradiated 9-ethylguanine crystals. Previous experimental results from X-irradiation and study of this system at 10 K found significant concentrations of two main products, R1, formed by N7-hydrogenation of the purine ring, and R2, the primary one-electron oxidation product (Jayatilaka, N.; Nelson, W. H. J. Phys. Chem. B 2007, 111, 7887). The objective of this work is to describe the processes leading to these products using computational methods that take into account molecular packing and bulk dielectric properties. The basic concept is that a proton will transfer following ionization if the net electronic energy of the system, consisting of the donor plus the acceptor plus any intervening molecules, becomes lower. Three approaches were used to investigate this concept, two based on energies computed for single molecules and one based on energies computed for two-molecule clusters arranged as in the crystals. The results are that the methods successfully predict the observed behavior, that it is energetically favorable on one-electron reduction for proton H1 to transfer from a neutral molecule to N7 of the neighbor, forming the N7-hydrogenated product, and that there is virtually no energy advantage for a proton to transfer upon one-electron oxidation. The results also support the proposal that the C8 H-addition radical, found only upon irradiation at 300 K, was the product of intramolecular transfer of the H7 proton to C8 in a process apparently requiring sufficient thermal energy for activation. Finally, the computations predict hyperfine couplings and tensors in very good agreement with those from experiment, thereby providing additional evidence for the success of the computations in describing the experimental observations.

  9. Oxidative catalysis using the stoichiometric oxidant as a reagent: an efficient strategy for single-electron-transfer-induced tandem anion-radical reactions.

    PubMed

    Kafka, František; Holan, Martin; Hidasová, Denisa; Pohl, Radek; Císařová, Ivana; Klepetářová, Blanka; Jahn, Ullrich

    2014-09-08

    Oxidative single-electron transfer-catalyzed tandem reactions consisting of a conjugate addition and a radical cyclization are reported, which incorporate the mandatory terminal oxidant as a functionality into the product.

  10. Timing of cell division in human cleavage-stage embryos is linked with blastocyst formation and quality.

    PubMed

    Cruz, María; Garrido, Nicolás; Herrero, Javier; Pérez-Cano, Inmaculada; Muñoz, Manuel; Meseguer, Marcos

    2012-10-01

    Noninvasive markers of embryo quality are being sought to improve IVF success. The present study aimed to discover possible associations between embryo division kinetics in the cleavage stage, the subsequent ability of human embryos to reach the blastocyst stage and the resulting blastocyst morphology. A retrospective cohort study analysed 834 embryos from 165 oocyte donation couples using a time-lapse monitoring system that allowed the recording of the exact timings for key events related to embryo development. Timing parameters were categorized into four quartiles. The probability of an embryo developing to a blastocyst was linked to a strict chronology of development. To further evaluate the relationships between these morphokinetic parameters and subsequent blastocyst formation, the ensuing blastocyst morphology was compared with a viability score based on a hierarchical classification of the cleavage-stage morphokinetic parameters. It is concluded that the kinetics of early embryo development and the potential for human embryos to develop to the blastocyst stage on day 5 are closely related and that time-lapse-based evaluation of the exact timing of early events in embryo development is a promising tool for the prediction of blastocyst formation and quality according to the proposed model.

  11. Optical and Electrical Characteristics of Graphene Double Layer Formed by a Double Transfer of Graphene Single Layers.

    PubMed

    Kim, Young Jun; Bae, Gi Yoon; Chun, Sungwoo; Park, Wanjun

    2016-03-01

    We demonstrate formation of double layer graphene by means of a double transfer using two single graphene layers grown by a chemical vapor deposition method. It is observed that shiftiness and broadness in the double-resonance of Raman scattering are much weaker than those of bilayer graphene formed naturally. Transport characteristics examined from transmission line measurements and field effect transistors show the similar behavior with those of single layer graphene. It indicates that interlayer separation, in electrical view, is large enough to avoid correlation between layers for the double layer structure. It is also observed from a transistor with the double layer graphene that molecules adsorpted on two inner graphene surfaces in the double layered structure are isolated and conserved from ambient environment.

  12. Divergence between organometallic and single-electron-transfer mechanisms in copper(II)-mediated aerobic C-H oxidation.

    PubMed

    Suess, Alison M; Ertem, Mehmed Z; Cramer, Christopher J; Stahl, Shannon S

    2013-07-03

    Copper(II)-mediated C-H oxidation is the subject of extensive interest in synthetic chemistry, but the mechanisms of many of these reactions are poorly understood. Here, we observe different products from Cu(II)-mediated oxidation of N-(8-quinolinyl)benzamide, depending on the reaction conditions. Under basic conditions, the benzamide group undergoes directed C-H methoxylation or chlorination. Under acidic conditions, the quinoline group undergoes nondirected chlorination. Experimental and computational mechanistic studies implicate an organometallic C-H activation/functionalization mechanism under the former conditions and a single-electron-transfer mechanism under the latter conditions. This rare observation of divergent, condition-dependent mechanisms for oxidation of a single substrate provides a valuable foundation for understanding Cu(II)-mediated C-H oxidation reactions.

  13. Structural and EPR characterisation of single electron and alkyl transfer products from reaction of dimethyl magnesium with bulky alpha-diimine ligands.

    PubMed

    Bailey, Philip J; Coxall, Robert A; Dick, Caroline M; Fabre, Sylvie; Parsons, Simon; Yellowlees, Lesley J

    2005-09-28

    Treatment of dimethylmagnesium with bulky alpha-diimine ligands provides either the biradical methyl-bridged complexes [(alpha-diimine-.)Mg+(mu-CH3)]2 via single electron transfer (SET), or the product of methyl transfer to an imine carbon atom depending upon conditions.

  14. Optimization of a vitrification protocol for hatched blastocysts from the dromedary camel (Camelus dromedarius).

    PubMed

    Herrid, M; Billah, M; Malo, C; Skidmore, J A

    2016-03-01

    The objective of this study was to modify and optimize a vitrification protocol (open pulled straw) that was originally designed for human oocytes and embryos, to make it suitable for the cryopreservation of camel hatched blastocysts. The original open pulled straw protocol was a complex process with 15-minute exposure of oocytes/embryos in 7.5% ethylene glycol (EG) and 7.5% dimethyl sulfoxide (Me2SO) for equilibration, and cooling in 16% EG + 16% Me2SO + 1 M sucrose. Recognizing a need to better control the cryoprotectant (CPA) concentrations, while avoiding toxicity to the embryos, the effects on the survival rate and developmental potential of camel embryos in vitro were investigated using two different methods of loading the CPAs into the embryos (stepwise and semicontinuous increase in concentration), two different loading temperature/time (room temperature ∼24 °C/15 min and body 37 °C/3 min), and the replacement of Me2SO with EG alone or in combination with glycerol (Gly). A total of 145 in vivo-derived embryos were subjected to these processes, and after warming their morphological quality and integrity, and re-expansion was assessed after 0, 2, 24, 48, 72, and 96 hours of culture. Exposure of embryos in a stepwise method was more beneficial to the survival of embryos than was the semicontinuous process, and loading of CPAs at 37 °C with a short exposure time (3 minutes) resulted in an outcome comparable to the original processing at room temperature with a longer exposure time (15 minutes). The replacement of the Me2SO + EG mixture with EG only or a combination of EG + Gly in the vitrification medium significantly improved the outcome of all these evaluation criteria (P < 0.05). The modified protocol of loading EG at 37 °C for 3 minutes has increased the embryo survival of the original protocol from 67% to 91% and the developmental rate from 57% to 83% at 5-day culture. These results were comparable to or better than those reported in human or other

  15. Studies of Nuclei Close to 132Sn Using Single-Neutron Transfer Reactions

    SciTech Connect

    Jones, K. L.; Pain, S. D.; Kozub, R. L.; Adekola, Aderemi S; Bardayan, Daniel W; Blackmon, Jeff C; Catford, Wilton N; Chae, K. Y.; Chipps, K.; Cizewski, J. A.; Erikson, Luke; Gaddis, A. L.; Greife, U.; Grzywacz, R. K.; Harlin, Christopher W; Hatarik, Robert; Howard, Joshua A; James, J.; Kapler, R.; Krolas, W.; Liang, J Felix; Ma, Zhanwen; Matei, Catalin; Moazen, Brian; Nesaraja, Caroline D; O'Malley, Patrick; Patterson, N. P.; Paulauskas, Stanley; Shapira, Dan; ShrinerJr., J. F.; Sikora, M.; Sissom, D. J.; Smith, Michael Scott; Swan, T. P.; Thomas, J. S.; Wilson, Gemma L

    2009-01-01

    Neutron transfer reactions were performed in inverse kinematics using radioactive ion beams of 132Sn, 130Sn, and 134Te and deuterated polyethylene targets. Preliminary results are presented. The Q-value spectra for 133Sn, 131Sn and 135Te reveal a number of previously unobserved peaks. The angular distributions are compatible with the expected lf7/2 nature of the ground state of 133Sn, and 2p3/2 for the 3.4 MeV state in 131Sn.

  16. Studies of nuclei close to {sup 132}Sn using single-neutron transfer reactions

    SciTech Connect

    Jones, K. J.; Pain, S. D.; Kozub, R. L.; Howard, J. A.; O'Malley, P. D.; Paulauskas, S. V.; Shriner, J. F.; Sissom, D. J.; Adekola, A. S.; Bardayan, D. W.; Blackmon, J. C.; Liang, J. F.; Nesaraja, C. D.; Shapira, D.; Smith, M. S.; Catford, W. N.; Harlin, C.; Patterson, N. P.; Swan, T. P.; Wilson, G. L.

    2009-03-04

    Neutron transfer reactions were performed in inverse kinematics using radioactive ion beams of {sup 132}Sn, {sup 130}Sn, and {sup 134}Te and deuterated polyethylene targets. Preliminary results are presented. The Q-value spectra for {sup 133}Sn, {sup 131}Sn and {sup 135}Te reveal a number of previously unobserved peaks. The angular distributions are compatible with the expected lf{sub 7/2} nature of the ground state of {sup 133}Sn, and 2p{sub 3/2} for the 3.4 MeV state in {sup 131}Sn.

  17. Completely ES cell-derived mice produced by tetraploid complementation using inner cell mass (ICM) deficient blastocysts.

    PubMed

    Wen, Duancheng; Saiz, Nestor; Rosenwaks, Zev; Hadjantonakis, Anna-Katerina; Rafii, Shahin

    2014-01-01

    Tetraploid complementation is often used to produce mice from embryonic stem cells (ESCs) by injection of diploid (2n) ESCs into tetraploid (4n) blastocysts (ESC-derived mice). This method has also been adapted to mouse cloning and the derivation of mice from induced pluripotent stem (iPS) cells. However, the underlying mechanism(s) of the tetraploid complementation remains largely unclear. Whether this approach can give rise to completely ES cell-derived mice is an open question, and has not yet been unambiguously proven. Here, we show that mouse tetraploid blastocysts can be classified into two groups, according to the presence or absence of an inner cell mass (ICM). We designate these as type a (presence of ICM at blastocyst stage) or type b (absence of ICM). ESC lines were readily derived from type a blastocysts, suggesting that these embryos retain a pluripotent epiblast compartment; whereas the type b blastocysts possessed very low potential to give rise to ESC lines, suggesting that they had lost the pluripotent epiblast. When the type a blastocysts were used for tetraploid complementation, some of the resulting mice were found to be 2n/4n chimeric; whereas when type b blastocysts were used as hosts, the resulting mice are all completely ES cell-derived, with the newborn pups displaying a high frequency of abdominal hernias. Our results demonstrate that completely ES cell-derived mice can be produced using ICM-deficient 4n blastocysts, and provide evidence that the exclusion of tetraploid cells from the fetus in 2n/4n chimeras can largely be attributed to the formation of ICM-deficient blastocysts.

  18. Unraveling electronic energy transfer in single conjugated polyelectrolytes encapsulated in lipid vesicles

    PubMed Central

    Karam, Pierre; Ngo, An Thien; Rouiller, Isabelle; Cosa, Gonzalo

    2010-01-01

    A method for the study of conjugated polyelectrolyte (CPE) photophysics in solution at the single-molecule level is described. Extended observation times of single polymer molecules are enabled by the encapsulation of the CPEs within 200-nm lipid vesicles, which are in turn immobilized on a surface. When combined with a molecular-level visualization of vesicles and CPE via cryo-transmission electron microscopy, these single-molecule spectroscopy studies on CPEs enable us to directly correlate the polymer conformation with its spectroscopic features. These studies are conducted with poly[5-methoxy-2-(3-sulfopropoxy)-1,4-phenylene-vinylene] (MPS-PPV, a negatively charged CPE), when encapsulated in neutral and in negatively charged lipid vesicles. MPS-PPV exists as a freely diffusing polymer when confined in negatively charged vesicles. Individual MPS-PPV molecules adopt a collapsed-chain conformation leading to efficient energy migration over multiple chromophores. Both the presence of stepwise photobleaching in fluorescence intensity-time trajectories and emission from low-energy chromophores along the chain are observed. These results correlate with the amplified sensing potential reported for MPS-PPV in aqueous solution. When confined within neutral vesicles, single MPS-PPV molecules adopt an extended conformation upon insertion in the lipid bilayer. In this case emission arises from multiple chromophores within the isolated polymer chains, leading to an exponential decay of the intensity over time and a broad blue-shifted emission spectrum. PMID:20876146

  19. Single-drop reactive extraction/extractive reaction with forced convective diffusion and interphase mass transfer

    NASA Technical Reports Server (NTRS)

    Kleinman, Leonid S.; Red, X. B., Jr.

    1995-01-01

    An algorithm has been developed for time-dependent forced convective diffusion-reaction having convection by a recirculating flow field within the drop that is hydrodynamically coupled at the interface with a convective external flow field that at infinity becomes a uniform free-streaming flow. The concentration field inside the droplet is likewise coupled with that outside by boundary conditions at the interface. A chemical reaction can take place either inside or outside the droplet, or reactions can take place in both phases. The algorithm has been implemented, and for comparison results are shown here for the case of no reaction in either phase and for the case of an external first order reaction, both for unsteady behavior. For pure interphase mass transfer, concentration isocontours, local and average Sherwood numbers, and average droplet concentrations have been obtained as a function of the physical properties and external flow field. For mass transfer enhanced by an external reaction, in addition to the above forms of results, we present the enhancement factor, with the results now also depending upon the (dimensionless) rate of reaction.

  20. Single-drop reactive extraction/extractive reaction with forced convective diffusion and interphase mass transfer

    NASA Technical Reports Server (NTRS)

    Kleinman, Leonid S.; Reed, X. B., Jr.

    1995-01-01

    An algorithm has been developed for the forced convective diffusion-reaction problem for convection inside and outside a droplet by a recirculating flow field hydrodynamically coupled at the droplet interface with an external flow field that at infinity becomes a uniform streaming flow. The concentration field inside the droplet is likewise coupled with that outside by boundary conditions at the interface. A chemical reaction can take place either inside or outside the droplet or reactions can take place in both phases. The algorithm has been implemented and results are shown here for the case of no reaction and for the case of an external first order reaction, both for unsteady behavior. For pure interphase mass transfer, concentration isocontours, local and average Sherwood numbers, and average droplet concentrations have been obtained as a function of the physical properties and external flow field. For mass transfer enhanced by an external reaction, in addition to the above forms of results, we present the enhancement factor, with the results now also depending upon the (dimensionless) rate of reaction.

  1. Debating Elective Single Embryo Transfer after in vitro Fertilization: A Plea for a Context-Sensitive Approach

    PubMed Central

    Ezugwu, EC; Van der Burg, S

    2015-01-01

    The number of embryos transferred after in vitro fertilization (IVF) have been a topic of debate for over a decade now. Due to the risk associated with multiple pregnancy, there has been a global effort at reducing the multiple pregnancy rates to a minimum while maintaining an acceptable level of successful IVF pregnancy rate. Elective single embryo transfer (eSET) is advocated in most European countries. In Belgium and Sweden, eSET is mandatory for couples with a good prognosis. However, despite clinical recommendations and policy statements, patients in clinical practice frequently do request for the transfer of multiple embryos in order to have twins. Such requests conflict with policy guidelines and create an ethical dilemma for physicians: Should the physician do as the couple requests, and there with respect the autonomy of patients, or adhere to medical policy that takes the health of the mother and children at heart? This article provides an exploration of the arguments found in the literature that plays a role in the discussion on this topic and eventually argues that what a physician should do depends on the specificities of the context in which patients and physicians are implicated. These contextual issues can be taken into account in a shared decision-making procedure, which allows reflections and the responsibilities of both patients and physicians to be attended in decision about assisted reproduction. PMID:25745568

  2. Quantifying kinetics from time series of single-molecule Förster resonance energy transfer efficiency histograms.

    PubMed

    Benke, Stephan; Nettels, Daniel; Hofmann, Hagen; Schuler, Benjamin

    2017-03-17

    Single-molecule fluorescence spectroscopy is a powerful approach for probing biomolecular structure and dynamics, including protein folding. For the investigation of nonequilibrium kinetics, Förster resonance energy transfer combined with confocal multiparameter detection has proven particularly versatile, owing to the large number of observables and the broad range of accessible timescales, especially in combination with rapid microfluidic mixing. However, a comprehensive kinetic analysis of the resulting time series of transfer efficiency histograms and complementary observables can be challenging owing to the complexity of the data. Here we present and compare three different methods for the analysis of such kinetic data: singular value decomposition, multivariate curve resolution with alternating least square fitting, and model-based peak fitting, where an explicit model of both the transfer efficiency histogram of each species and the kinetic mechanism of the process is employed. While each of these methods has its merits for specific applications, we conclude that model-based peak fitting is most suitable for a quantitative analysis and comparison of kinetic mechanisms.

  3. Quantitative description of the lie-to-sit-to-stand-to-walk transfer by a single body-fixed sensor.

    PubMed

    Bagalà, Fabio; Klenk, Jochen; Cappello, Angelo; Chiari, Lorenzo; Becker, Clemens; Lindemann, Ulrich

    2013-07-01

    Sufficient capacity and quality of performance of complex movement patterns during daily activity, such as standing up from a bed, is a prerequisite for independent living and also may be an indicator of fall risk. Until now, the transfer from lying-to-sit-to-stand-to-walk (LSSW) was investigated by functional testing, subjective rating or for activity classification of subtasks. The aim of this study was to use a single body-fixed inertial sensor to describe the complex movement of the LSSW transfer. Fifteen older patients of a geriatric rehabilitation clinic (median age 81 years) and ten young, healthy persons (median age 37 years) were instructed to stand up from bed in a continuous movement and to start walking. Data acquisition was performed using an inertial measurement unit worn on the lower back. Parameters extracted from the sensor outputs were able to correctly classify the subjects into a correct group with sensitivity and specificity between 90% and 100%. ICCs 3,1 of the descriptive parameters ranged between 0.85 and 0.95 in the cohort of older patients. The different strategies adopted to transfer from lying to standing up were estimated through an extended Kalman filter. The results obtained in this study suggest the usability of the instrumented LSSW test in clinical settings.

  4. Exciton Recombination, Energy-, and Charge Transfer in Single- and Multilayer Quantum-Dot Films on Silver Plasmonic Resonators

    NASA Astrophysics Data System (ADS)

    Shin, Taeho; Cho, Kyung-Sang; Yun, Dong-Jin; Kim, Jinwoo; Li, Xiang-Shu; Moon, Eui-Seong; Baik, Chan-Wook; Il Kim, Sun; Kim, Miyoung; Choi, Jun Hee; Park, Gyeong-Su; Shin, Jai-Kwang; Hwang, Sungwoo; Jung, Tae-Sung

    2016-05-01

    We examine exciton recombination, energy-, and charge transfer in multilayer CdS/ZnS quantum dots (QDs) on silver plasmonic resonators using photoluminescence (PL) and excitation spectroscopy along with kinetic modeling and simulations. The exciton dynamics including all the processes are strongly affected by the separation distance between QDs and silver resonators, excitation wavelength, and QD film thickness. For a direct contact or very small distance, interfacial charge transfer and tunneling dominate over intrinsic radiative recombination and exciton energy transfer to surface plasmons (SPs), resulting in PL suppression. With increasing distance, however, tunneling diminishes dramatically, while long-range exciton-SP coupling takes place much faster (>6.5 ns) than intrinsic recombination (~200 ns) causing considerable PL enhancement. The exciton-SP coupling strength shows a strong dependence on excitation wavelengths, suggesting the state-specific dynamics of excitons and the down-conversion of surface plasmons involved. The overlayers as well as the bottom monolayer of QD multilayers exhibit significant PL enhancement mainly through long-range exciton-SP coupling. The overall emission behaviors from single- and multilayer QD films on silver resonators are described quantitatively by a photophysical kinetic model and simulations. The present experimental and simulation results provide important and useful design rules for QD-based light harvesting applications using the exciton-surface plasmon coupling.

  5. Quantifying kinetics from time series of single-molecule Förster resonance energy transfer efficiency histograms

    NASA Astrophysics Data System (ADS)

    Benke, Stephan; Nettels, Daniel; Hofmann, Hagen; Schuler, Benjamin

    2017-03-01

    Single-molecule fluorescence spectroscopy is a powerful approach for probing biomolecular structure and dynamics, including protein folding. For the investigation of nonequilibrium kinetics, Förster resonance energy transfer combined with confocal multiparameter detection has proven particularly versatile, owing to the large number of observables and the broad range of accessible timescales, especially in combination with rapid microfluidic mixing. However, a comprehensive kinetic analysis of the resulting time series of transfer efficiency histograms and complementary observables can be challenging owing to the complexity of the data. Here we present and compare three different methods for the analysis of such kinetic data: singular value decomposition, multivariate curve resolution with alternating least square fitting, and model-based peak fitting, where an explicit model of both the transfer efficiency histogram of each species and the kinetic mechanism of the process is employed. While each of these methods has its merits for specific applications, we conclude that model-based peak fitting is most suitable for a quantitative analysis and comparison of kinetic mechanisms.

  6. Exciton Recombination, Energy-, and Charge Transfer in Single- and Multilayer Quantum-Dot Films on Silver Plasmonic Resonators

    PubMed Central

    Shin, Taeho; Cho, Kyung-Sang; Yun, Dong-Jin; Kim, Jinwoo; Li, Xiang-Shu; Moon, Eui-Seong; Baik, Chan-Wook; Il Kim, Sun; Kim, Miyoung; Choi, Jun Hee; Park, Gyeong-Su; Shin, Jai-Kwang; Hwang, Sungwoo; Jung, Tae-Sung

    2016-01-01

    We examine exciton recombination, energy-, and charge transfer in multilayer CdS/ZnS quantum dots (QDs) on silver plasmonic resonators using photoluminescence (PL) and excitation spectroscopy along with kinetic modeling and simulations. The exciton dynamics including all the processes are strongly affected by the separation distance between QDs and silver resonators, excitation wavelength, and QD film thickness. For a direct contact or very small distance, interfacial charge transfer and tunneling dominate over intrinsic radiative recombination and exciton energy transfer to surface plasmons (SPs), resulting in PL suppression. With increasing distance, however, tunneling diminishes dramatically, while long-range exciton-SP coupling takes place much faster (>6.5 ns) than intrinsic recombination (~200 ns) causing considerable PL enhancement. The exciton-SP coupling strength shows a strong dependence on excitation wavelengths, suggesting the state-specific dynamics of excitons and the down-conversion of surface plasmons involved. The overlayers as well as the bottom monolayer of QD multilayers exhibit significant PL enhancement mainly through long-range exciton-SP coupling. The overall emission behaviors from single- and multilayer QD films on silver resonators are described quantitatively by a photophysical kinetic model and simulations. The present experimental and simulation results provide important and useful design rules for QD-based light harvesting applications using the exciton-surface plasmon coupling. PMID:27184469

  7. SCC-DFTB Energy Barriers for Single and Double Proton Transfer Processes in the Model Molecular Systems Malonaldehyde and Porphycene

    SciTech Connect

    Walewski, L.; Krachtus, D; Fischer, S.; Smith, Jeremy C; Bala, P.; Lesyng, B.

    2005-09-01

    Self-consistent charge-density functional tight-binding SCC-DFTB is a computationally efficient method applicable to large (bio)molecular systems in which (bio)chemical reactions may occur. Among these reactions are proton transfer processes. This method, along with more advanced ab initio techniques, is applied in this study to compute intramolecular barriers for single and double proton transfer processes in the model systems, malonaldehyde and porphycene, respectively. SCC-DFTB is compared with experimental data and higher-level ab initio calculations. For malonaldehyde, the SCC-DFTB barrier height is 3.1 kcal/mol in vacuo and 4.2 kcal/mol in water solution. In the case of porphycene, the minimum energy pathways for double intramolecular proton transfer were determined using the conjugate peak refinement (CPR) method. Six isomers of porphycene were ordered according to energy. The only energetically allowed pathway was found to connect two symmetrical trans states via an unstable cis-A isomer. The SCC-DFTB barrier heights are 11.1 kcal/mol for the trans-cis-A process, and 7.4 kcal/mol for the reverse cis-A-trans one with the energy difference of 3.7 kcal/mol between the trans- and cis-A states. The method provides satisfactory energy results when compared with reference ab initio and experimental data.

  8. Debating Elective Single Embryo Transfer after in vitro Fertilization: A Plea for a Context-Sensitive Approach.

    PubMed

    Ezugwu, Ec; der Burg, S Van

    2015-01-01

    The number of embryos transferred after in vitro fertilization (IVF) have been a topic of debate for over a decade now. Due to the risk associated with multiple pregnancy, there has been a global effort at reducing the multiple pregnancy rates to a minimum while maintaining an acceptable level of successful IVF pregnancy rate. Elective single embryo transfer (eSET) is advocated in most European countries. In Belgium and Sweden, eSET is mandatory for couples with a good prognosis. However, despite clinical recommendations and policy statements, patients in clinical practice frequently do request for the transfer of multiple embryos in order to have twins. Such requests conflict with policy guidelines and create an ethical dilemma for physicians: Should the physician do as the couple requests, and there with respect the autonomy of patients, or adhere to medical policy that takes the health of the mother and children at heart? This article provides an exploration of the arguments found in the literature that plays a role in the discussion on this topic and eventually argues that what a physician should do depends on the specificities of the context in which patients and physicians are implicated. These contextual issues can be taken into account in a shared decision-making procedure, which allows reflections and the responsibilities of both patients and physicians to be attended in decision about assisted reproduction.

  9. Automated Hydrogen/Deuterium Exchange Electron Transfer Dissociation High Resolution Mass Spectrometry Measured at Single-Amide Resolution

    NASA Astrophysics Data System (ADS)

    Landgraf, Rachelle R.; Chalmers, Michael J.; Griffin, Patrick R.

    2012-02-01

    Hydrogen deuterium exchange mass spectrometry (HDX-MS) is a well established method for the measurement of solution-phase deuterium incorporation into proteins, which can provide insight into protein conformational mobility. However, most HDX measurements are constrained to regions of the protein where pepsin proteolysis allows detection at peptide resolution. Recently, single-amide resolution deuterium incorporation has been achieved by limiting gas-phase scrambling in the mass spectrometer. This was accomplished by employing a combination of soft ionization and desolvation conditions coupled with the radical-driven fragmentation technique electron transfer dissociation (ETD). Here, a hybrid LTQ-Orbitrap XL is systematically evaluated for its utility in providing single-amide deuterium incorporation for differential HDX analysis of a nuclear receptor upon binding small molecule ligands. We are able to show that instrumental parameters can be optimized to minimize scrambling and can be incorporated into an established and fully automated HDX platform making differential single-amide HDX possible for bottom-up analysis of complex systems. We have applied this system to determine differential single amide resolution HDX data for the peroxizome proliferator activated receptor bound with two ligands of interest.

  10. Experimental Investigation of the Discharge Coefficient and Impingement Heat Transfer Characteristics of a Single Jet in Cross Flow

    NASA Astrophysics Data System (ADS)

    Roberts, Brian

    This experimentation investigates the local heat transfer characteristics of an impinging jet with the effects of cross flow. The jet is formed by a single round hole with a diameter of 0.25 inches, sharp edges and a length to diameter ratio of 4. For one combination of impingement plate spacing and cross flow to jet flow mass velocity ratio, detailed photographs of a sheet of liquid crystal were taken. These photographs were then used to create a Nusselt number contour plot. Observations are made regarding the comparison of the Nusselt number contour plots with and without cross flow. Comparisons are also made to data in open literature citing the degradation of the average Nusselt number with cross flow to that without cross flow. While the main focus of this study was the heat transfer of an impinging jet, a large amount of discharge coefficient data was also gathered for a single, sharp edged, round hole in the presence of cross flow. It compared very well to other investigator's data and a correlation relating the discharge coefficient to the mass velocity ratio is reported.

  11. Study of sequential dexter energy transfer in high efficient phosphorescent white organic light-emitting diodes with single emissive layer.

    PubMed

    Kim, Jin Wook; You, Seung Il; Kim, Nam Ho; Yoon, Ju-An; Cheah, Kok Wai; Zhu, Fu Rong; Kim, Woo Young

    2014-11-12

    In this study, we report our effort to realize high performance single emissive layer three color white phosphorescent organic light emitting diodes (PHOLEDs) through sequential Dexter energy transfer of blue, green and red dopants. The PHOLEDs had a structure of; ITO(1500 Å)/NPB(700 Å)/mCP:Firpic-x%:Ir(ppy)3-0.5%:Ir(piq)3-y%(300 Å)/TPBi(300 Å)/Liq(20 Å)/Al(1200 Å). The dopant concentrations of FIrpic, Ir(ppy)3 and Ir(piq)3 were adjusted and optimized to facilitate the preferred energy transfer processes attaining both the best luminous efficiency and CIE color coordinates. The presence of a deep trapping center for charge carriers in the emissive layer was confirmed by the observed red shift in electroluminescent spectra. White PHOLEDs, with phosphorescent dopant concentrations of FIrpic-8.0%:Ir(ppy)3-0.5%:Ir(piq)3-0.5% in the mCP host of the single emissive layer, had a maximum luminescence of 37,810 cd/m(2) at 11 V and a luminous efficiency of 48.10 cd/A at 5 V with CIE color coordinates of (0.35, 0.41).

  12. Study of Sequential Dexter Energy Transfer in High Efficient Phosphorescent White Organic Light-Emitting Diodes with Single Emissive Layer

    NASA Astrophysics Data System (ADS)

    Kim, Jin Wook; You, Seung Il; Kim, Nam Ho; Yoon, Ju-An; Cheah, Kok Wai; Zhu, Fu Rong; Kim, Woo Young

    2014-11-01

    In this study, we report our effort to realize high performance single emissive layer three color white phosphorescent organic light emitting diodes (PHOLEDs) through sequential Dexter energy transfer of blue, green and red dopants. The PHOLEDs had a structure of; ITO(1500 Å)/NPB(700 Å)/mCP:Firpic-x%:Ir(ppy)3-0.5%:Ir(piq)3-y%(300 Å)/TPBi(300 Å)/Liq(20 Å)/Al(1200 Å). The dopant concentrations of FIrpic, Ir(ppy)3 and Ir(piq)3 were adjusted and optimized to facilitate the preferred energy transfer processes attaining both the best luminous efficiency and CIE color coordinates. The presence of a deep trapping center for charge carriers in the emissive layer was confirmed by the observed red shift in electroluminescent spectra. White PHOLEDs, with phosphorescent dopant concentrations of FIrpic-8.0%:Ir(ppy)3-0.5%:Ir(piq)3-0.5% in the mCP host of the single emissive layer, had a maximum luminescence of 37,810 cd/m2 at 11 V and a luminous efficiency of 48.10 cd/A at 5 V with CIE color coordinates of (0.35, 0.41).

  13. Enhancement of adoptive T cell transfer with single low dose pretreatment of doxorubicin or paclitaxel in mice.

    PubMed

    Hsu, Fei-Ting; Chen, Tzu-Chun; Chuang, Hui-Yen; Chang, Ya-Fang; Hwang, Jeng-Jong

    2015-12-29

    Ex vivo expansion of CD8+ T-cells has been a hindrance for the success of adoptive T cell transfer in clinic. Currently, preconditioning with chemotherapy is used to modulate the patient immunity before ACT, however, the tumor microenvironment beneficial for transferring T cells may also be damaged. Here preconditioning with single low dose of doxorubicin or paclitaxel combined with fewer CD8+ T-cells was investigated to verify whether the same therapeutic efficacy of ACT could be achieved. An E.G7/OT1 animal model that involved adoptive transfer of OVA-specific CD8+ T-cells transduced with a granzyme B promoter-driven firefly luciferase and tomato fluorescent fusion reporter gene was used to evaluate this strategy. The result showed that CD8+ T-cells were activated and sustained longer in mice pretreated with one low-dose Dox or Tax. Enhanced therapeutic efficacy was found in Dox or Tax combined with 2x106 CD8+ T-cells and achieved the same level of tumor growth inhibition as that of 5x106 CD8+ T-cells group. Notably, reduced numbers of Tregs and myeloid derived suppressor cells were shown in combination groups. By contrast, the number of tumor-infiltrating cytotoxic T lymphocytes and IL-12 were increased. The NF-κB activity and immunosuppressive factors such as TGF-β, IDO, CCL2, VEGF, CCL22, COX-2 and IL-10 were suppressed. This study demonstrates that preconditioning with single low dose Dox or Tax and combined with two fifth of the original CD8+ T-cells could improve the tumor microenvironment via suppression of NF-κB and its related immunosuppressors, and activate more CD8+ T-cells which also stay longer.

  14. SU-E-QI-15: Single Point Dosimetry by Means of Cerenkov Radiation Energy Transfer (CRET)

    SciTech Connect

    Volotskova, O; Jenkins, C; Xing, L

    2014-06-15

    Purpose: Cerenkov light is generated when a charged particles with energy greater then 250 keV, moves faster than the speed of light in a given medium. Both x-ray photons and electrons produce optical Cerenkov photons during the static megavoltage linear accelerator (LINAC) operational mode. Recently, Cerenkov radiation gained considerable interest as possible candidate as a new imaging modality. Optical signals generated by Cerenkov radiation may act as a surrogate for the absorbed superficial radiation dose. We demonstrated a novel single point dosimetry method for megavoltage photon and electron therapy utilizing down conversion of Cerenkov photons. Methods: The custom build signal characterization system was used: a sample holder (probe) with adjacent light tight compartments was connected via fiber-optic cables to a photon counting photomultiplier tube (PMT). One compartment contains a medium only while the other contains medium and red-shifting nano-particles (Q-dots, nanoclusters). By taking the difference between the two signals (Cerenkov photons and CRET photons) we obtain a measure of the down-converted light, which we expect to be proportional to dose as measured with an adjacent ion chamber. Experimental results are compared to Monte Carlo simulations performed using the GEANT4 code. Results: The signal correlation between CR signal, CRET readings and dose produced by LINAC at a single point were investigated. The experimental results were compared with simulations. The dose linearity, signal to noise ratio and dose rate dependence were tested with custom build CRET based probe. Conclusion: Performance characteristics of the proposed single point CRET based probe were evaluated. The direct use of the induced Cerenkov emission and CRET in an irradiated single point volume as an indirect surrogate for the imparted dose was investigated. We conclude that CRET is a promising optical based dosimetry method that offers advantages over those already proposed.

  15. Single-Phase Active Boost Rectifier with Power Factor Correction for Wireless Power Transfer Applications

    SciTech Connect

    Chinthavali, Madhu Sudhan; Onar, Omer C; Miller, John M; Tang, Lixin

    2013-01-01

    Wireless Power Transfer (WPT) technology is a novel research area in the charging technology that bridges utility and the automotive industries. There are various solutions that are currently being evaluated by several research teams to find the most efficient way to manage the power flow from the grid to the vehicle energy storage system. There are different control parameters that can be utilized to compensate for the change in the impedance. To understand the power flow through the system this paper presents a novel approach to the system model and the impact of different control parameters on the load power. The implementation of an active front-end rectifier on the grid side for power factor control and voltage boost capability for load power regulation is also discussed.

  16. Heat and mass transfer in semiconductor melts during single-crystal growth processes

    NASA Astrophysics Data System (ADS)

    Kakimoto, Koichi

    1995-03-01

    The quality of large semiconductor crystals grown from melts is significantly affected by the heat and mass transfer in the melts. The current understanding of the phenomena, especially melt convection, is reviewed starting from the results of visualization using model fluids or silicon melt, and continuing to the detailed numerical calculations needed for quantitative modeling of processing with solidification. The characteristics of silicon flows are also reviewed by focusing on the Coriolis force in the rotating melt. Descriptions of flow instabilities are included that show the level of understanding of melt convection with a low Prandtl number. Based on hydrodynamics, the origin of the silicon flow structure is reviewed, and it is discussed whether silicon flow is completely turbulent or has an ordered structure. The phase transition from axisymmetric to nonaxisymmetric flow is discussed using different geometries. Additionally, surface-tension-driven flow is reviewed for Czochralski crystal growth systems.

  17. Generalization Effects in Evaluative Conditioning: Evidence for Attitude Transfer Effects from Single Exemplars to Social Categories

    PubMed Central

    Glaser, Tina; Kuchenbrandt, Dieta

    2017-01-01

    The present research investigated whether evaluatively conditioned attitudes toward members of a social category (CSs) generalize to other stimuli belonging to the same category as the CSs (generalization at the stimulus level) and to the category itself (generalization at the category level). In four experiments, USs were paired with schematic or naturalistic CSs belonging to certain fictitious groups. Afterward, attitudes toward the CSs, toward non-presented exemplars of the CS category, and toward the CS category were assessed. Results revealed evidence for generalization effects in EC on both the stimulus and the category level. Transfer effects were greater when participants’ awareness of the CS–US contingency (CA) was high. Moreover, we found differences in generalization between the stimulus and category level, indicating that different processes might contribute to the effects. Theoretical and practical implications such as using EC as a tool for changing attitudes toward social groups will be discussed. PMID:28197118

  18. Electron Transfer between Cytochrome C and Cytochome C Peroxidase in Single Crystals

    SciTech Connect

    Kang, Seong A.; Marjavaara, Pieti J.; Crane, Brian R.

    2010-11-10

    Cytochrome c (Cc) and cytochrome c peroxidase (CcP) form an important redox pair for understanding interprotein electron transfer (ET). Measurements of ET rates from photoexcited CcP substituted with Zn porphyrin to either yeast Fe(III)Cc or horse Fe(III)Cc in crystals reveal that the molecular associations found in the respective crystal structures determine solution reactivity. Similar forward rates for yeast isozyme-1 Cc (yCc) and yCc homologue horse Cc (hCc), despite different orientations relative to CcP, suggest small-amplitude conformational gating of ET even in the crystalline state; faster back ET in the yCc compared to the hCc complex agrees with the relative coupling between redox sites predicted by the structures.

  19. Device study, chemical doping, and logic circuits based on transferred aligned single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Wang, Chuan; Ryu, Koungmin; Badmaev, Alexander; Patil, Nishant; Lin, Albert; Mitra, Subhasish; Wong, H.-S. Philip; Zhou, Chongwu

    2008-07-01

    In this paper, high-performance back-gated carbon nanotube field-effect transistors based on transferred aligned carbon nanotubes were fabricated and studies found that the on/off ratio can reach 107 and the current density can reach 1.6μA/μm after electrical breakdown. In addition, chemical doping with hydrazine was used to convert the p-type aligned nanotube devices into n-type. These devices were further utilized to demonstrate various logic circuits, including p-type metal-oxide-semiconductor inverters, diode-loaded inverters, complementary metal-oxide-semiconductor inverters, NAND, and NOR gates. This approach could work as the platform for future nanotube-based nanoelectronics.

  20. Effects of synchronous and asynchronous embryo transfer on postnatal development, adult health, and behavior in mice.

    PubMed

    López-Cardona, Angela P; Fernández-González, Raúl; Pérez-Crespo, Miriam; Alén, Francisco; de Fonseca, Fernando Rodriguez; Orio, Laura; Gutierrez-Adan, Alfonso

    2015-10-01

    Asynchronous embryo transfer (ET) is a common assisted reproduction technique used in several species, but its biological effects on postnatal and early development remain unknown. The aim of this study was to determine whether asynchronous ET produces long-term effects in mice. Postnatal development, animal weight, systolic blood pressure (SBP), relative organ weight (liver, spleen, kidneys, heart, lungs, brain, and testicles), and behavior (assessed in open-field and elevated plus maze tests) were assessed in CD1 mice produced by different ET procedures: 1) the transfer of Day 3.5 (D3.5) blastocysts to the uterus (BL-UT); 2) the transfer of D3.5 blastocysts to the oviduct (BL-OV); or 3) the transfer of D0.5 zygotes to the oviduct (Z-OV). In vivo conceived animals served as controls (CT). The transfer of blastocysts to the uterus or zygotes to the oviduct was defined as synchronous, and transfer of blastocysts to the oviduct was defined as asynchronous. Both synchronous and asynchronous ET resulted in increased weight at birth that normalized thereafter with the exception of asynchronous ET females. In this group, female BL-OV, a clear lower body weight was recorded along postnatal life when compared with controls (P < 0.05). No effects on animal weight were produced during postnatal development in the synchronous ET groups (BL-UT, Z-OV, and CT). Both synchronous and asynchronous ET had impacts on adult (Wk 30) organ weight. SBP was modified in animals derived from blastocyst but not zygote ET. Effects on behavior (anxiety in the plus maze) were only detected in the BL-UT group (P < 0.05). Our findings indicate that zygotes are less sensitive than blastocysts to ET and that both synchronous and asynchronous blastocyst ET may have long-term consequences on health, with possible impacts on weight, arterial pressure, relative organ weight, and behavior.

  1. The Dnmt3b splice variant is specifically expressed in in vitro-manipulated blastocysts and their derivative ES cells.

    PubMed

    Horii, Takuro; Suetake, Isao; Yanagisawa, Eikichi; Morita, Sumiyo; Kimura, Mika; Nagao, Yasumitsu; Imai, Hiroshi; Tajima, Shoji; Hatada, Izuho

    2011-10-01

    Manipulation of preimplantation embryos in vitro, such as in vitro fertilization (IVF), in vitro culture (IVC), intracytoplasmic sperm injection (ICSI), somatic cell nuclear transfer (SCNT) and other assisted reproduction technologies (ART), has contributed to the development of infertility treatment and new animal reproduction methods. However, such embryos often exhibit abnormal DNA methylation patterns in imprinted genes and centromeric satellite repeats. These DNA methylation patterns are established and maintained by three DNA methyltransferases: Dnmt1, Dnmt3a and Dnmt3b. Dnmt3b is responsible for the creation of methylation patterns during the early stage of embryogenesis and consists of many alternative splice variants that affect methylation activity; nevertheless, the roles of these variants have not yet been identified. In this study, we found an alternatively spliced variant of Dnmt3b lacking exon 6 (Dnmt3bΔ6) that is specific to mouse IVC embryos. Dnmt3bΔ6 also showed prominent expression in embryonic stem (ES) cells derived from in vitro manipulated embryos. Interestingly, IVC blastocysts were hypomethylated in centromeric satellite repeat regions that could be susceptible to methylation by Dnmt3b. In vitro methylation activity assays showed that Dnmt3bΔ6 had lower activity than normal Dnmt3b. Our findings suggest that Dnmt3bΔ6 could induce a hypomethylation status especially in in vitro manipulated embryos.

  2. Cloned calves derived from somatic cell nuclear transfer embryos cultured in chemically defined medium or modified synthetic oviduct fluid.

    PubMed

    Jang, Goo; Hong, So Gun; Lee, Byeong Chun

    2011-03-01

    Somatic cell nuclear transfer (SCNT) is considered to be a critical tool for propagating valuable animals. To determine the productivity calves resulting from embryos derived with different culture media, enucleated oocytes matured in vitro were reconstructed with fetal fibroblasts, fused, and activated. The cloned embryos were cultured in modified synthetic oviduct fluid (mSOF) or a chemically defined medium (CDM) and developmental competence was monitored. After 7 days of culturing, the blastocysts were transferred into the uterine horn of estrus-synchronized recipients. SCNT embryos that were cultured in mSOF or CDM developed to the blastocysts stages at similar rates (26.6% vs. 22.5%, respectively). A total of 67 preimplantational stage embryos were transferred into 34 recipients and six cloned calves were born by caesarean section, or assisted or natural delivery. Survival of transferred blastocysts to live cloned calves in the mSOF and the CDM was 18.5% (to recipients), 9.6% (to blastocysts) and 42.9% (to recipients), 20.0% (to blastocysts), respectively. DNA analysis showed that all cloned calves were genetically identical to the donor cells. These results demonstrate that SCNT embryos cultured in CDM showed higher viability as judged by survival of the calves that came to term compared to blastocysts derived from mSOF cultures.

  3. Mitochondrial DNA variations in ova and blastocyst: implications in assisted reproduction.

    PubMed

    Shamsi, Monis Bilal; Govindaraj, Periyasamy; Chawla, Latika; Malhotra, Neena; Singh, Neeta; Mittal, Suneeta; Talwar, Pankaj; Thangaraj, Kumarasamy; Dada, Rima

    2013-03-01

    Mitochondrial DNA (mtDNA) of oocyte is critical for its function, embryo quality and development. Analysis of complete mtDNA of 49 oocytes and 18 blastocysts from 67 females opting for IVF revealed 437 nucleotide variations. 40.29% samples had either disease associated or non-synonymous novel or pathogenic mutation in evolutionarily conserved regions. Samples with disease associated mtDNA mutations had low fertilization rate and poor embryo quality, however no difference in implantation or clinical pregnancy rate was observed. Screening mtDNA from oocyte/blastocyst is a simple, clinically reliable method for diagnostic evaluation of female infertility and may reduce risk of mtDNA disease transmission.

  4. Effects of lead on the male mouse as investigated by in vitro fertilization and blastocyst culture

    SciTech Connect

    Johansson, L.; Sjoeblom, P.; Wide, M.

    1987-02-01

    Long-term exposure of male mice to inorganic lead (lead chloride, 1 g/liter) in the drinking water reduces their fertility. The cause of this reduction, expressed as a decrease in the number of mated females showing inplantations, was investigated, using an in vivo fertilization method. It was found that spermatozoa from lead-exposed males had a significantly lower ability to fertilize mouse eggs than those from unexposed males. Preimplantation embryos, isolated from uterine horns of mice mated with lead-exposed males. Preimplantation embryos, isolated from uterine horns of mice mated with lead-exposed males, were examined. No morphologically abnormal embryos were found. However, when cultured in vitro over the implantation period, blastocysts of the group mated with lead-exposed males showed an increased frequency of delayed hatching from the zona pellucida or an inability to hatch. Among blastocysts from this group a decreased frequency of inner cell mass development was also found.

  5. Monozygotic twins with discordant karyotypes following preimplantation genetic screening and single embryo transfer: case report

    PubMed Central

    Gaillyova, Renata; Travnik, Pavel; Oracova, Eva; Vesela, Katerina; Hromadova, Lenka; Vesely, Jan; Musilova, Petra; Rubes, Jiri; Kadlecova, Jitka; Slamova, Iva; Makaturova, Eva; Vranova, Vladimira

    2010-01-01

    Purpose To report a case of monozygotic monochorial diamniotic twins with discordant karyotypes. Methods and results The pregnancy was achieved following a treatment cycle with intracytoplasmic sperm injection (ICSI) and preimplantation genetic screening (PGS) for chromosomes X, Y, 13, 16, 18, 21, 22. One embryo euploid for studied chromosomes was transferred. Prenatal ultrasonography revealed monozygotic twins. One fetus had growth retardation, multiple organ abnormalities and polyhydramnion. The other twin had normal ultrasound appearance. Delivery on week 29 of gestation resulted in the birth of two females, a stillborn twin with karyotype 45,XX,-13[12]/46,XX,r(13)[3] and a healthy twin with normal karyotype. Conclusions The discordance in the twins’ karyotypes originated from a mosaic embryo. Structural chromosomal abnormality of the affected twin could not be revealed using standard PGS investigation. Embryo splitting occurred probably due to apoptotic process in an early stage of embryo development. Apoptosis represents one of the possible mechanisms which can explain the embryo twinning process globally. PMID:20700760

  6. The Effects of Perioperative Analgesia on Litter Size in Crl:CD1(ICR) Mice Undergoing Embryo Transfer

    PubMed Central

    Goulding, David R; Myers, Page H; Goulding, Eugenia H; Blankenship, Terry L; Grant, Mary F; Forsythe, Diane B

    2010-01-01

    The objective of this study was to evaluate the effect on litter size of 2 analgesics used perioperatively during mouse embryo transfer surgery. Day 2.5 pseudopregnant CD1 mice (n = 96) were divided equally into 2 analgesic treatment groups and a saline control group. Each mouse received a single, subcutaneous dose of buprenorphine hydrochloride (0.1 mg/kg), flunixin meglumine (2.5 mg/kg), or saline immediately after induction of anesthesia with 2.5% isoflurane. Each mouse then was prepared for aseptic surgery. Blastocysts had previously been collected from C57BL/6NCrl female mice that were synchronized and superovulated by using pregnant mare serum gonadotropin and human chorionic gonadotropin and mated with C57BL/6NTac male mice 3.5 d before collection. Viable blastocysts were pooled, and 8 were selected arbitrarily and transplanted into the right uterine horn of each pseudopregnant CD1 mouse. Mice were monitored throughout pregnancy, and the number of pups at birth was documented. No statistically significant difference was found between the 3 groups. These results indicate that perioperative analgesic treatment with buprenorphine or flunixin in the CD1 mouse undergoing embryo transfer is not associated with increased embryonic loss. PMID:20819387

  7. Innate immunity in an in vitro murine blastocyst model using embryonic and trophoblast stem cells.

    PubMed

    Aikawa, Hiroaki; Tamai, Miho; Mitamura, Keisuke; Itmainati, Fakhria; Barber, Glen N; Tagawa, Yoh-ichi

    2014-03-01

    The immune system has two broad components-innate and adaptive immunity. Adaptive immunity becomes established only after the onset of hematopoiesis, whereas the innate immune system may be actively protecting organisms from microbial invasion much earlier in development. Here, we address the question of whether the innate immune system functions in the early-stage embryo, i.e., the blastocyst. The innate immune system was studied by using in vitro blastocyst models, e.g., embryonic stem (ES) and trophoblast stem (TS) cell cultures. The expression of Toll-like receptors (TLR)-2, -3, and -5 could be detected in both ES and TS cells. The expression of interferon (IFN)-β was induced by the addition of polyinosinic:polycytidylic acid [poly(I:C)] in TS cells, but not ES cells, although TLR-3 was expressed at the same level in both cell types. In turn, ES cells responded to IFN-β exposure by expressing IFN-induced anti-viral genes, e.g., RNA-dependent protein kinase and 2', 5'-oligoadenylate synthetase (OAS). Neither a reduction in ES cell proliferation nor cell death in these cultures was observed after IFN-β stimulation. Furthermore, OAS1a expression was induced in ES/TS co-cultures after poly(I:C) stimulation, but was not induced when either cell type was cultured alone. In conclusion, TS cells react to poly(I:C) stimulation by producing IFN-β, which induces IFN-inducible genes in ES cells. This observation suggests that the trophectoderm, the outer layer of the blastocyst, may respond to viral infection, and then induce anti-viral gene expression via IFN-β signaling to the blastocyst inner cell mass.

  8. HIPPO pathway members restrict SOX2 to the inner cell mass where it promotes ICM fates in the mouse blastocyst.

    PubMed

    Wicklow, Eryn; Blij, Stephanie; Frum, Tristan; Hirate, Yoshikazu; Lang, Richard A; Sasaki, Hiroshi; Ralston, Amy

    2014-10-01

    Pluripotent epiblast (EPI) cells, present in the inner cell mass (ICM) of the mouse blastocyst, are progenitors of both embryonic stem (ES) cells and the fetus. Discovering how pluripotency genes regulate cell fate decisions in the blastocyst provides a valuable way to understand how pluripotency is normally established. EPI cells are specified by two consecutive cell fate decisions. The first decision segregates ICM from trophectoderm (TE), an extraembryonic cell type. The second decision subdivides ICM into EPI and primitive endoderm (PE), another extraembryonic cell type. Here, we investigate the roles and regulation of the pluripotency gene Sox2 during blastocyst formation. First, we investigate the regulation of Sox2 patterning and show that SOX2 is restricted to ICM progenitors prior to blastocyst formation by members of the HIPPO pathway, independent of CDX2, the TE transcription factor that restricts Oct4 and Nanog to the ICM. Second, we investigate the requirement for Sox2 in cell fate specification during blastocyst formation. We show that neither maternal (M) nor zygotic (Z) Sox2 is required for blastocyst formation, nor for initial expression of the pluripotency genes Oct4 or Nanog in the ICM. Rather, Z Sox2 initially promotes development of the primitive endoderm (PE) non cell-autonomously via FGF4, and then later maintains expression of pluripotency genes in the ICM. The significance of these observations is that 1) ICM and TE genes are spatially patterned in parallel prior to blastocyst formation and 2) both the roles and regulation of Sox2 in the blastocyst are unique compared to other pluripotency factors such as Oct4 or Nanog.

  9. Occurrence of amitotic division of trophoblast cell nuclei in blastocysts of the western spotted skunk (Spilogale putorius latifrons).

    PubMed

    Isakova, Galina K; Mead, Rodney A

    2004-01-01

    A cytogenetic examination of spreaded cells of diapausing and early activated blastocysts obtained from 7 female western spotted skunks was performed. Mitosis was not observed in 1626 cells obtained from 9 diapausing blastocysts; however, 12 (1.5%) figures of diploid mitosis were seen in 851 cells from 5 early activated embryos. Diameter of the cell nuclei varied from 4 to 29 microm during diapause, and from 5 to 40 microm in activated blastocyst, and the heterogeneity in nuclear size was significantly different between diapausing and activated embryos (P<0.01). About 80% of nuclei from diapausing blastocysts measured 9 to 16 microm, whereas a similar percentage of nuclei from activated blastocysts ranged from 15 to 27 microm. Many enlarged nuclei exhibited morphological features characteristic of mammalian polytene (i.e. endopolyploid with polytenic organization of chromosomes) trophoblast cells. The number of silver stained nucleoli in all the nuclei did not exceed 2, which corresponds to the number of nucleolus organizers in the diploid karyotype in this species of skunk and suggests the polytene organization of chromosomes in enlarged nuclei. About 10% of large interphase nuclei were observed to undergo amitosis, i.e. direct division by constriction. The resulting nuclear fragments in diapausing blastocysts usually had normal morphology and active nucleoli. In activated embryos, nearly 15% of amitotically divided nuclei appeared to be dividing into fragments of unequal size, one of which had normal cell nuclear morphology and extremely large silver positive nucleoli, and the other fragment exhibited signs of cell death. We interpret these data as indicating that 1) amitotic division of trophoblast endopolyploid cell nuclei in the skunk blastocysts may generate new trophoblast cells which contribute to increased cell number during both diapause and activation stages, and 2) activation of blastocysts after diapause is related to the production of trophoblast

  10. Single quantum vibrational energy transfer from HCl (v=2) and HBr(v=2)

    SciTech Connect

    Dasch, C.J.; Moore, C.B.

    1980-04-01

    HCl (v=2) and HBr (v=2) have been directly excited with a pulsed optical parametric oscillator at 295 K. The relaxation in hydrogen halide mixtures proceeds largely by single quantum V--V exchange. Measured total relaxation rates include HCl..-->..HCl 9.5 +- 0.7; HCl..-->..HBr 9.3 +- 0.6; HCl..-->..DCl 1.3 +- 0.2; HBr..-->..HBr 6.2 +- 0.5; and HBr..-->..HCl (1.0 +- 0.2) x 10/sup 4/ Torr/sup -1/ s/sup -1/. The two quantum exchange rate for HCl (v=2)+ HBr (v=0) is <1 x 10/sup 3/ Torr/sup -1/ s/sup -1/. Upper limits on the V--R, T self-relaxation rates of HCl (v=2) and HBr (v=2) are 2 x and 1 x 10/sup 4/ Torr/sup -1/ s/sup -1/.

  11. Curcumin prevents methylglyoxal-induced oxidative stress and apoptosis in mouse embryonic stem cells and blastocysts.

    PubMed

    Hsuuw, Yan-Der; Chang, Chen-Kang; Chan, Wen-Hsiung; Yu, Jau-Song

    2005-12-01

    Methylglyoxal (MG) is a reactive dicarbonyl compound endogenously produced mainly from glycolytic intermediates. Elevated MG levels in diabetes patients are believed to contribute to diabetic complications. MG is cytotoxic through induction of apoptosis. Curcumin, the yellow pigment of Curcuma longa, is known to have antioxidant and anti-inflammatory properties. In the present study, we examined the effect of curcumin on apoptotic biochemical events caused by incubation of ESC-B5 cells with MG. Curcumin inhibited the MG-induced DNA fragmentation, caspase-3 activation, cleavage of PARP, mitochondrial cytochrome c release, and JNK activation. Importantly, curcumin also inhibited the MG-stimulated increase of reactive oxygen species (ROS) in these cells. In addition, we demonstrated that curcumin prevented the MG-induced apoptosis of mouse blastocysts isolated from pregnant mice. Moreover, curcumin significantly reduced the MG-mediated impairment of blastocyst development from mouse morulas. The results support the hypothesis that curcumin inhibits MG-induced apoptosis in mouse ESC-B5 cells and blastocysts by blocking ROS formation and subsequent apoptotic biochemical events.

  12. CXADR is required for AJ and TJ assembly during porcine blastocyst formation.

    PubMed

    Kwon, Jeong-Woo; Kim, Nam-Hyung; Choi, Inchul

    2016-04-01

    Coxsackie virus and adenovirus receptor (CXADR) is a member of the immunoglobulin superfamily as well as a member of the junctional adhesion molecule family of adhesion receptor. In human pre-implantation embryos, CXADR was detected and co-localized with tight junction (TJ) proteins on the membrane of the trophectoderm. However, its physiological roles were not elucidated in terms of blastocyst formation. Here, we reported expression patterns and biological functions of CXADR in porcine pre-implantation embryos. The transcripts of CXADR were detected at all stages of pre-implantation. Particularly, its expression dramatically increased and preferentially localized at the edge of cell-cell contacts, rather than in the nucleus from the eight-cell stage onwards. CXADR expression was knocked down (KD) by microinjecting double-stranded RNA into one-cell parthenotes. The vast majority of CXADR KD embryos failed to develop to the blastocyst stage, and a few developed KD blastocysts did not expand fully. Analysis of adherens junction (AJ)- and TJ-associated genes/proteins using qRT-PCR, immunocytochemistry and assessment of TJ permeability using FITC-dextran uptake assay revealed that the developmental failure and relatively small cavities are attributed to the defects of TJ assembly. In summary, CXADR is necessary for the AJ and TJ assembly/biogenesis during pre-implantation development.

  13. Targeted organ generation using Mixl1-inducible mouse pluripotent stem cells in blastocyst complementation.

    PubMed

    Kobayashi, Toshihiro; Kato-Itoh, Megumi; Nakauchi, Hiromitsu

    2015-01-15

    Generation of functional organs from patients' own cells is one of the ultimate goals of regenerative medicine. As a novel approach to creation of organs from pluripotent stem cells (PSCs), we employed blastocyst complementation in organogenesis-disabled animals and successfully generated PSC-derived pancreas and kidneys. Blastocyst complementation, which exploits the capacity of PSCs to participate in forming chimeras, does not, however, exclude contribution of PSCs to the development of tissues-including neural cells or germ cells-other than those specifically targeted by disabling of organogenesis. This fact provokes ethical controversy if human PSCs are to be used. In this study, we demonstrated that forced expression of Mix-like protein 1 (encoded by Mixl1) can be used to guide contribution of mouse embryonic stem cells to endodermal organs after blastocyst injection. We then succeeded in applying this method to generate functional pancreas in pancreatogenesis-disabled Pdx1 knockout mice using a newly developed tetraploid-based organ-complementation method. These findings hold promise for targeted organ generation from patients' own PSCs in livestock animals.

  14. UDP-Glucuronosyltransferase 1a Enzymes Are Present and Active in the Mouse Blastocyst

    PubMed Central

    Yamauchi, Yasuhiro; Sato, Brittany L.M.; Rougée, Luc R.A.; Ward, Monika A.

    2014-01-01

    The UDP-glucuronosyltransferase (UGT) enzymes are critical for regulating nutrients, hormones, and endobiotics, as well as for detoxifying xenobiotics. Human and murine fetuses are known to express glucuronidation enzymes, but there are currently no data prior to implantation. Here we addressed this gap in knowledge and tested whether Ugt enzymes are already present in preimplantation-stage embryos. Blastocysts were obtained after in vitro fertilization with gametes from B6D2F1 hybrid mice and from embryo culture. Protein expression and localization were determined using pan-specific UGT1A and UGT2B, as well as anti-human isoform-specific antibodies. Immunofluorescence analysis showed that blastocysts expressed Ugt1a globally, in the cytoplasm and nuclei of all of the cells. Western blots demonstrated the presence of Ugt1a6 but not Ugt1a1, Ugt1a3, Ugt1a4, or Ugt1a9. The Ugt2b proteins were not detected by either assay. The level of Ugt activity in murine blastocysts was comparable with that of the adult human liver (per milligram of protein), but the activity of β-glucuronidase, an Ugt-partnering enzyme responsible for substrate regeneration, was lower. Altogether, these data confirm that Ugt1a proteins are present and active in preimplantation murine embryos and point to a potential role for these proteins in implantation and early embryonic and fetal development. PMID:25200869

  15. The effect of the site of laser zona opening on the complete hatching of mouse blastocysts and their cell numbers

    PubMed Central

    Sanmee, Usanee; Piromlertamorn, Waraporn

    2016-01-01

    Objective We studied the effect of the site of laser zona opening on the complete hatching of mouse blastocysts and the cell numbers of the completely hatched blastocysts. Methods Mouse blastocysts were randomly allocated to the inner cell mass (ICM) group (zona opening performed at the site of the ICM, n=125), the trophectoderm (TE) group (zona opening performed opposite to the ICM, n=125) and the control group (no zona opening, n=125). Results The rate of complete hatching of the blastocysts was not significantly different in the ICM and the TE group (84.8% vs 80.8%, respectively; p=0.402), but was significantly lower in the control group (51.2%, p<0.001). The cell numbers in the completely hatched blastocysts were comparable in the control group, the ICM group, and the TE group (69±19.3, 74±15.7, and 71±16.8, respectively; p=0.680). Conclusion These findings indicate that the site of laser zona opening did not influence the rate of complete hatching of mouse blastocysts or their cell numbers. PMID:27689037

  16. Melatonin promotes the in vitro development of pronuclear embryos and increases the efficiency of blastocyst implantation in murine.

    PubMed

    Wang, Feng; Tian, XiuZhi; Zhang, Lu; Tan, DunXian; Reiter, Russel J; Liu, GuoShi

    2013-10-01

    When a defect occurs in the in vitro development of a pronuclear embryo, the interruption of the subsequent implantation limits the success of assisted conception. This common problem remains to be solved. In this study, we observed that melatonin at its physiological concentration (10(-7)  m) significantly promoted the in vitro development of murine pronuclear embryos. This was indicated by the increased blastocyst rate, hatching blastocyst rate, and blastocyst cell number with melatonin treatment. In addition, when these blastocysts were implanted into female recipient mice, the pregnancy rates (95.0% versus control 67.8%), litter sizes (4.1 pups/litter versus control 2.7 pups/litter), and postnatal survival rates of offspring (96.84% versus control 81.24%) were significantly improved compared with their non-melatonin-treated counterparts. Mechanistic studies revealed that melatonin treatment upregulates gene expression of the antioxidant enzyme, superoxide dismutase (SOD), and the anti-apoptotic factor bcl-2 while downregulating the expression of pro-apoptotic genes p53 and caspase-3. Due to these changes, melatonin treatment reduces ROS production and cellular apoptosis during in vitro embryo development and improves the quality of blastocysts. The implantation of blastocysts with higher quality leads to more healthy offspring and increased pup survival.

  17. Fast, long-range, reversible conformational fluctuations in nucleosomes revealed by single-pair fluorescence resonance energy transfer

    NASA Astrophysics Data System (ADS)

    Tomschik, Miroslav; Zheng, Haocheng; van Holde, Ken; Zlatanova, Jordanka; Leuba, Sanford H.

    2005-03-01

    The nucleosome core particle, the basic repeated structure in chromatin fibers, consists of an octamer of eight core histone molecules, organized as dimers (H2A/H2B) and tetramers [(H3/H4)2] around which DNA wraps tightly in almost two left-handed turns. The nucleosome has to undergo certain conformational changes to allow processes that need access to the DNA template to occur. By single-pair fluorescence resonance energy transfer, we demonstrate fast, long-range, reversible conformational fluctuations in nucleosomes between two states: fully folded (closed), with the DNA wrapped around the histone core, or open, with the DNA significantly unraveled from the histone octamer. The brief excursions into an extended open state may create windows of opportunity for protein factors involved in DNA transactions to bind to or translocate along the DNA. conformational transitions | evanescent field fluorescence microscope | nucleosome dynamics | nucleosome opening

  18. Bipolar Latissimus Dorsi Transfer through a Single Incision: First Key–Step in Poland Syndrome Chest Deformity

    PubMed Central

    di Summa, Pietro G.; Raffoul, Wassim

    2016-01-01

    Summary: Poland syndrome is a rare congenital anomaly characterized by a unilateral congenital absence of the sternocostal head of the pectoralis major muscle. The absence of the pectoralis major does not only result in chest asymmetry but also in a missing anterior axillary fold, which is essential for natural anatomical appearance in both male and female patients. In Poland syndrome patients, we perform bipolar latissimus dorsi flap transfer, which can be associated with a sublatissimus implant in women. All procedures are performed through a single short midaxillary incision, and tendon translocation in this technique allows the creation of the anterior axillary fold and thus a natural chest appearance. Moreover, this technique can be performed by any plastic surgeon operating under a basic operating room setting. PMID:27622115

  19. SiC MOSFET Based Single Phase Active Boost Rectifier with Power Factor Correction for Wireless Power Transfer Applications

    SciTech Connect

    Onar, Omer C; Tang, Lixin; Chinthavali, Madhu Sudhan; Campbell, Steven L; Miller , John M.

    2014-01-01

    Wireless Power Transfer (WPT) technology is a novel research area in the charging technology that bridges the utility and the automotive industries. There are various solutions that are currently being evaluated by several research teams to find the most efficient way to manage the power flow from the grid to the vehicle energy storage system. There are different control parameters that can be utilized to compensate for the change in the impedance due to variable parameters such as battery state-of-charge, coupling factor, and coil misalignment. This paper presents the implementation of an active front-end rectifier on the grid side for power factor control and voltage boost capability for load power regulation. The proposed SiC MOSFET based single phase active front end rectifier with PFC resulted in >97% efficiency at 137mm air-gap and >95% efficiency at 160mm air-gap.

  20. Carbene-catalysed reductive coupling of nitrobenzyl bromides and activated ketones or imines via single-electron-transfer process

    PubMed Central

    Li, Bao-Sheng; Wang, Yuhuang; Proctor, Rupert S. J.; Zhang, Yuexia; Webster, Richard D.; Yang, Song; Song, Baoan; Chi, Yonggui Robin

    2016-01-01

    Benzyl bromides and related molecules are among the most common substrates in organic synthesis. They are typically used as electrophiles in nucleophilic substitution reactions. These molecules can also be activated via single-electron-transfer (SET) process for radical reactions. Representative recent progress includes α-carbon benzylation of ketones and aldehydes via photoredox catalysis. Here we disclose the generation of (nitro)benzyl radicals via N-heterocyclic carbene (NHC) catalysis under reductive conditions. The radical intermediates generated via NHC catalysis undergo formal 1,2-addition with ketones to eventually afford tertiary alcohol products. The overall process constitutes a formal polarity-inversion of benzyl bromide, allowing a direct coupling of two initially electrophilic carbons. Our study provides a new carbene-catalysed reaction mode that should enable unconventional transformation of (nitro)benzyl bromides under mild organocatalytic conditions. PMID:27671606

  1. Correlated blinking via time dependent energy transfer in single CdSe quantum dot-dye nanoassemblies

    NASA Astrophysics Data System (ADS)

    Gerlach, Frank; Täuber, Daniela; von Borczyskowski, Christian

    2013-05-01

    Optical confocal spectroscopy on self-assembled single nanoassemblies from CdSe/ZnS quantum dots (QD) and perylene diimide dye molecules demonstrates efficient Förster resonance energy transfer (FRET). Intramolecular dynamics of the flexible dye molecule change the FRET efficiency in course of the detection period of several minutes. This can be followed by correlated observations of luminescence intensities and related spectral shifts of both constituents. Contrary to several experiments on similar assemblies, the FRET efficiencies are by almost one order of magnitude larger in the non-polar liquid solvent TEHOS as compared e.g. to toluene. Experimental and theoretically expected efficiencies are in close agreement with each other.

  2. Subdomain-specific collapse of denatured staphylococcal nuclease revealed by single molecule fluorescence resonance energy transfer measurements.

    PubMed

    Liu, Pengcheng; Meng, Xianglan; Qu, Peng; Zhao, Xin Sheng; Wang, Chih-chen

    2009-09-03

    By using single molecule fluorescence resonance energy transfer (smFRET), the equilibrium denaturation of staphylococcal nuclease (SNase) induced by guanidinium hydrochloride (GdmCl) has been investigated. We have characterized the collapse of the denatured chain and its relation to structure formation. Two mutants, K28C/H124C and K28C/K97C, were constructed and labeled for monitoring the behaviors of the global molecule and the beta subdomain, respectively. For both the labeled mutants, only native and non-native conformations were observed, and the non-native conformations expanded with increasing GdmCl concentrations. The non-native chains of the two derivatives exhibited different changes of persistence length at higher GdmCl concentrations, suggesting a subdomain-specific collapse of the denatured state of SNase. This local chain specific collapse is likely to play a role in modulating the formation of early intermediate during protein folding.

  3. Optical horn antennas for efficiently transferring photons from a quantum emitter to a single-mode optical fiber.

    PubMed

    Grosjean, T; Mivelle, M; Burr, G W; Baida, F I

    2013-01-28

    We theoretically demonstrate highly efficient optical coupling between a single quantum emitter and a monomode optical fiber over remarkably broad spectral ranges by extending the concept of horn antenna to optics. The optical horn antenna directs the radiation from the emitter toward the optical fiber and efficiently phase-matches the photon emission with the fiber mode. Numerical results show that an optical horn antenna can funnel up to 85% of the radiation from a dipolar source within an emission cone semi-angle as small as 7 degrees (antenna directivity of 300). It is also shown that 50% of the emitted power from the dipolar source can be collected and coupled to an SMF-28 fiber mode over spectral ranges larger than 1000 nm, with a maximum energy transfer reaching 70 %. This approach may open new perspectives in quantum optics and sensing.

  4. Biological construction of single-walled carbon nanotube electron transfer pathways in dye-sensitized solar cells.

    PubMed

    Inoue, Ippei; Watanabe, Kiyoshi; Yamauchi, Hirofumi; Ishikawa, Yasuaki; Yasueda, Hisashi; Uraoka, Yukiharu; Yamashita, Ichiro

    2014-10-01

    We designed and mass-produced a versatile protein supramolecule that can be used to manufacture a highly efficient dye-sensitized solar cell (DSSC). Twelve single-walled carbon-nanotube (SWNT)-binding and titanium-mineralizing peptides were genetically integrated on a cage-shaped dodecamer protein (CDT1). A process involving simple mixing of highly conductive SWNTs with CDT1 followed by TiO2 biomineralization produces a high surface-area/weight TiO2 -(anatase)-coated intact SWNT nanocomposite under environmentally friendly conditions. A DSSC with a TiO2 photoelectrode containing 0.2 wt % of the SWNT-TiO2 nanocomposite shows a current density improvement by 80% and a doubling of the photoelectric conversion efficiency. The SWNT-TiO2 nanocomposite transfers photon-generated electrons from dye molecules adsorbed on the TiO2 to the anode electrode swiftly.

  5. Carbene-catalysed reductive coupling of nitrobenzyl bromides and activated ketones or imines via single-electron-transfer process

    NASA Astrophysics Data System (ADS)

    Li, Bao-Sheng; Wang, Yuhuang; Proctor, Rupert S. J.; Zhang, Yuexia; Webster, Richard D.; Yang, Song; Song, Baoan; Chi, Yonggui Robin

    2016-09-01

    Benzyl bromides and related molecules are among the most common substrates in organic synthesis. They are typically used as electrophiles in nucleophilic substitution reactions. These molecules can also be activated via single-electron-transfer (SET) process for radical reactions. Representative recent progress includes α-carbon benzylation of ketones and aldehydes via photoredox catalysis. Here we disclose the generation of (nitro)benzyl radicals via N-heterocyclic carbene (NHC) catalysis under reductive conditions. The radical intermediates generated via NHC catalysis undergo formal 1,2-addition with ketones to eventually afford tertiary alcohol products. The overall process constitutes a formal polarity-inversion of benzyl bromide, allowing a direct coupling of two initially electrophilic carbons. Our study provides a new carbene-catalysed reaction mode that should enable unconventional transformation of (nitro)benzyl bromides under mild organocatalytic conditions.

  6. Complexation of dimethylmagnesium with alpha-diimines; structural and EPR characterisation of single electron and alkyl transfer products.

    PubMed

    Bailey, Philip J; Dick, Caroline M; Fabre, Sylvie; Parsons, Simon; Yellowlees, Lesley J

    2006-04-07

    Treatment of dimethylmagnesium with the alpha-diimine ligands Ar'N=C(R)C(R)=NAr' [R = naphth-1,8-diyl (1), H (2), CH3 (3); Ar' = 2,6-diisopropylphenyl] in diethyl ether provides the neutral methyl-bridged dimeric complexes [(alpha-diimine-.)Mg+(mu-CH3)]2 via single electron transfer (SET) to the coordinated diimine and elimination of a methyl radical. These biradical species have been characterised by EPR spectroscopy and, for the ligand , X-ray crystallography. In the presence of THF the reaction of ligand proceeds to the diamagnetic [(ene-1,2-diamide)Mg(THF)3] complex in which the diimine ligand has been doubly reduced to an ene-diamide by two successive SET processes. Comparison of the structural data for the free ligand with that obtained for the alpha-diimine radical anion and ene-diamide complexes shows the expected increases in C-N, and decreases in C-C, bond lengths within the N-C-C-N unit consistent with the progressive reduction of the ligand. In the case of ligand , reaction at low temperature provides the complex [Mg(mu2-Me){Ar'NC(Me)2C(Me)NAr'}]2 in which methyl transfer to a ligand imine carbon atom has occurred. This species has also been structurally characterised. This contrasts with the formation of the radical species at room temperature, and indicates the involvement of an intermediate in which the radical products of the SET process are held in close proximity by the solvent cage. Two competing processes of methyl radical escape and methyl transfer to the ligand account for the formation of the observed products at different temperatures.

  7. Xanthones as antioxidants: a theoretical study on the thermodynamics and kinetics of the single electron transfer mechanism.

    PubMed

    Martínez, Ana; Hernández-Marin, Elizabeth; Galano, Annia

    2012-04-01

    Mangosteen (Garcinia mangostana) is considered the queen of the tropical fruits. It has a dark red pericarp that is rich in bioactive compounds including xanthones, which have been classified as very good antioxidants from several experimental results. In this work, the antioxidant properties of twenty xanthones isolated from the pericarp of Garcinia mangostana are studied considering the single electron transfer mechanism (SET). According to their most acidic pK(a) value, under physiological conditions the monoanionic form is present in significant amounts. For this reason, eight deprotonated xanthones are also considered in this study. Quantum chemical calculations were performed in order to assess their free radical scavenging capacity in terms of vertical ionization energies and vertical electron affinities. With these two chemical descriptors it is possible to construct a map that allows a straightforward comparison of the electron transfer viability between any pair of reactants. Such a map for the studied xanthones and the free radicals ˙OH and O(2)˙(-), in aqueous solution, indicates that xanthones can either donate or accept electrons in order to deactivate free radicals. A new relationship between the ionization potential and the electron affinity is proposed to predict the thermochemical viability of the SET processes. The electron transfer reactions between xanthones and ˙OH or O(2)˙(-) are endergonic and, therefore, thermodynamically unfeasible. However, the reaction of deprotonated xanthones with ˙OH is exergonic. Thus, the deprotonated xanthones are more reactive than the neutral species through the SET mechanism. The monoanions of xanthones, which are present under physiological conditions were found to react with ˙OH at diffusion-limited rates.

  8. Charge-transfer pipi* excited state in the 7-azaindole dimer. A hybrid configuration interactions singles/time-dependent density functional theory description.

    PubMed

    Gelabert, Ricard; Moreno, Miquel; Lluch, José M

    2006-01-26

    The hybrid configuration interaction singles/time dependent density functional theory approach of Dreuw and Head-Gordon [Dreuw, A.; Head-Gordon, M. J. Am. Chem. Soc. 2004, 126, 4007] has been applied to study the potential energy landscape and accessibility of the charge-transfer pipi* excited state in the dimer of 7-azaindole, which has been traditionally considered a model for DNA base pairing. It is found that the charge-transfer pipi* excited state preferentially stabilizes the product of a single proton transfer. In this situation, the crossing between this state and the photoactive electronic state of the dimer is accessible. It is found that the charge-transfer pipi* excited state has a very steep potential energy profile with respect to any single proton-transfer coordinate and, in contrast, an extremely flat potential energy profile with respect to the stretch of the single proton-transfer complex. This is predicted to bring about a pair of rare fragments of the 7-azaindole dimer, physically separated and hence having very long lifetimes. This could have implications in the DNA base pairs of which the system is an analogue, in the form of replication errors.

  9. Troika of the mouse blastocyst: lineage segregation and stem cells.

    PubMed

    Artus, Jerome; Hadjantonakis, Anna-Katerina

    2012-01-01

    The initial period of mammalian embryonic development is primarily devoted to cell commitment to the pluripotent lineage, as well as to the formation of extraembryonic tissues essential for embryo survival in utero. This phase of development is also characterized by extensive morphological transitions. Cells within the preimplantation embryo exhibit extraordinary cell plasticity and adaptation in response to experimental manipulation, highlighting the use of a regulative developmental strategy rather than a predetermined one resulting from the non-uniform distribution of maternal information in the cytoplasm. Consequently, early mammalian development represents a useful model to study how the three primary cell lineages; the epiblast, primitive endoderm (also referred to as the hypoblast) and trophoblast, emerge from a totipotent single cell, the zygote. In this review, we will discuss how the isolation and genetic manipulation of murine stem cells representing each of these three lineages has contributed to our understanding of the molecular basis of early developmental events.

  10. Heat transfer and oil flow studies on a single-stage-to-orbit control-configured winged entry vehicle

    NASA Technical Reports Server (NTRS)

    Helms, V. T., III; Bradley, P. F.

    1984-01-01

    Results are presented for oil flow and phase change paint heat transfer tests conducted on a 0.006 scale model of a proposed single stage to orbit control configured vehicle. The data were taken at angles of attack up to 40 deg at a free stream Mach number of 10 for Reynolds numbers based on model length of 0.5 x 10 to the 6th power, 1.0 x 10 to the 6th power and 2.0 x 10 to the 6th power. The magnitude and distribution of heating are characterized in terms of angle of attack and Reynolds number aided by an analysis of the flow data which are used to suggest the presence of various three dimensional flow structures that produce the observed heating patterns. Of particular interest are streak heating patterns that result in high localized heat transfer rates on the wing windward surface at low to moderate angles of attack. These streaks are caused by the bow-shock/wing-shock interaction and formation of the wing-shock. Embedded vorticity was found to be associated with these interactions.

  11. Ab initio characterization of electron transfer coupling in photoinduced systems: generalized Mulliken-Hush with configuration-interaction singles.

    PubMed

    Chen, Hung-Cheng; Hsu, Chao-Ping

    2005-12-29

    To calculate electronic couplings for photoinduced electron transfer (ET) reactions, we propose and test the use of ab initio quantum chemistry calculation for excited states with the generalized Mulliken-Hush (GMH) method. Configuration-interaction singles (CIS) is proposed to model the locally excited (LE) and charge-transfer (CT) states. When the CT state couples with other high lying LE states, affecting coupling values, the image charge approximation (ICA), as a simple solvent model, can lower the energy of the CT state and decouple the undesired high-lying local excitations. We found that coupling strength is weakly dependent on many details of the solvent model, indicating the validity of the Condon approximation. Therefore, a trustworthy value can be obtained via this CIS-GMH scheme, with ICA used as a tool to improve and monitor the quality of the results. Systems we tested included a series of rigid, sigma-linked donor-bridge-acceptor compounds where "through-bond" coupling has been previously investigated, and a pair of molecules where "through-space" coupling was experimentally demonstrated. The calculated results agree well with experimentally inferred values in the coupling magnitudes (for both systems studied) and in the exponential distance dependence (for the through-bond series). Our results indicate that this new scheme can properly account for ET coupling arising from both through-bond and through-space mechanisms.

  12. Studying 10BE and 11BE Halo States Through The (P,D) Single-Neutron Transfer Reaction

    NASA Astrophysics Data System (ADS)

    Kuhn, Keri; Sarazin, Fred; Tigress Collaboration; (Pcb)2 Collaboration

    2016-09-01

    One-neutron transfer reactions are being used to study single-particle neutron states in nuclei. For one-neutron halo nuclei, such as 11Be, the (p,d) reaction enables the removal of the halo neutron or of one of the core neutrons. This way, it is possible to simultaneously study the halo wavefunction of the 11Be ground-state but also a possible excited halo state in 10Be. The 11Be(p, d)10Be transfer reaction at 10 MeV/nucleon is being investigated at the TRIUMF-ISAC II facility with the Printed Circuit Board Based Charged Particle ((PCB)2) array inside the TRIUMF ISAC Gamma-Ray Escape-Suppressed Spectrometer (TIGRESS). The ground state and first excited state of 10Be can be directly identified using deuteron identification and kinematics from the charged particle array, while the four excited states in10Be around 6 MeV, including the suspected halo state (2- state), are identified using coincident gamma rays from TIGRESS with the identified deuterons. Angular distributions for the 10Be populated states will be shown along with their FRESCO fits. This work is partially supported by the US Department of Energy through Grant/Contract No. DE-FG03- 93ER40789.

  13. Studying 10Be and 11Be Halo States through the (p,d) Single-Neutron Transfer Reaction

    NASA Astrophysics Data System (ADS)

    Kuhn, Keri; Sarazin, Fred; (Pcb)2 Collaboration; Tigress Collaboration

    2015-10-01

    One-neutron transfer reactions are being used to study single-particle neutron states in nuclei. For one-neutron halo nuclei, such as 11Be, the (p,d) reaction enables the removal of the halo neutron or of one of the core neutrons. This way, it is possible to simultaneously study the halo wavefunction of the 11Be ground-state but also a possible excited halo state in 10Be. The 11Be(p, d)10Be transfer reaction at 10 MeV/nucleon is being investigated at the TRIUMF-ISAC II facility with the Printed Circuit Board Based Charged Particle ((PCB)2) array inside the TRIUMF ISAC Gamma-Ray Escape-Suppressed Spectrometer (TIGRESS). The ground state and first excited state of 10Be can be directly identified using deuteron identification and kinematics from the charged particle array, while the four excited states in10Be around 6 MeV, including the suspected halo state (2- state), are identified using coincident gamma rays from TIGRESS with the identified deuterons. Angular distributions for the 10Be populated states will be shown along with their FRESCO fits. This work is partially supported by the US Department of Energy through Grant/Contract No. DE-FG03-93ER40789 (Colorado School of Mines).

  14. Dnmt3l-knockout donor cells improve somatic cell nuclear transfer reprogramming efficiency.

    PubMed

    Liao, Hung-Fu; Mo, Chu-Fan; Wu, Shinn-Chih; Cheng, Dai-Han; Yu, Chih-Yun; Chang, Kai-Wei; Kao, Tzu-Hao; Lu, Chia-Wei; Pinskaya, Marina; Morillon, Antonin; Lin, Shih-Shun; Cheng, Winston T K; Bourc'his, Déborah; Bestor, Timothy; Sung, Li-Ying; Lin, Shau-Ping

    2015-10-01

    Nuclear transfer (NT) is a technique used to investigate the development and reprogramming potential of a single cell. DNA methyltransferase-3-like, which has been characterized as a repressive transcriptional regulator, is expressed in naturally fertilized egg and morula/blastocyst at pre-implantation stages. In this study, we demonstrate that the use of Dnmt3l-knockout (Dnmt3l-KO) donor cells in combination with Trichostatin A treatment improved the developmental efficiency and quality of the cloned embryos. Compared with the WT group, Dnmt3l-KO donor cell-derived cloned embryos exhibited increased cell numbers as well as restricted OCT4 expression in the inner cell mass (ICM) and silencing of transposable elements at the blastocyst stage. In addition, our results indicate that zygotic Dnmt3l is dispensable for cloned embryo development at pre-implantation stages. In Dnmt3l-KO mouse embryonic fibroblasts, we observed reduced nuclear localization of HDAC1, increased levels of the active histone mark H3K27ac and decreased accumulation of the repressive histone marks H3K27me3 and H3K9me3, suggesting that Dnmt3l-KO donor cells may offer a more permissive epigenetic state that is beneficial for NT reprogramming.

  15. Sodium current in single cells from bullfrog atrium: voltage dependence and ion transfer properties.

    PubMed Central

    Clark, R B; Giles, W

    1987-01-01

    1. Whole-cell and patch-clamp techniques (Hamill, Marty, Neher, Sakmann & Sigworth, 1981) have been used to make quantitative measurements of the transient inward sodium current (INa) in single cells from bullfrog atrium. This preparation is particularly suitable for the study of INa: (i) the current density is relatively low, (ii) the cells lack a transverse tubule system, (iii) isolated myocytes can be maintained at reduced temperatures (approximately 8-12 degrees C); therefore kinetics can be studied quantitatively. 2. INa was pharmacologically and kinetically isolated from other transmembrane currents by blocking ICa with CdCl2 (0.2-0.5 mM) or LaCl3 (5 x 10(-6) M), and by using only relatively short voltage-clamp depolarizations which did not activate IK (the delayed rectifier). 3. The voltage dependence of INa in bullfrog atrium is similar to that in amphibian node of Ranvier or fast skeletal muscle. The threshold for activation is approximately -50 mV. The peak of the INa vs. membrane potential relation is near -5 to -10 mV. The reversal potential in 'normal' (115 mM-Na+) Ringer solution is +59.0 mV (S.D. +/- 3.4, n = 10). Reduction of external Na+ concentration to one-third of normal resulted in an approximately -27 mV shift of the reversal potential, close to that expected for a highly Na+-selective conductance. 4. Steady-state inactivation of INa (h infinity), measured with a conventional two-pulse voltage-clamp protocol, spanned the membrane potential range from -90 to -50 mV. The potential dependence of h infinity was well described by a single Boltzmann function with half-inactivation at -71 mV and maximum slope of 6.0 mV. 5. Steady-state activation of INa (m infinity) was determined from fits of INa records to a Hodgkin-Huxley model. The potential dependence of m infinity was fitted to a Boltzmann function with half-activation at -33 mV and maximum slope of 9.5 mV. Thus at temperatures around 10 degrees C there was very little overlap of the m infinity

  16. Spectroscopic Studies of Doping and Charge Transfer in Single Walled Carbon Nanotubes and Lead Sulfide Quantum Dots

    NASA Astrophysics Data System (ADS)

    Haugen, Neale O.

    The use of single wall carbon nanotubes (SW-CNTs) in solar photovoltaic (PV) devices is a relatively new, but quickly growing field. SW-CNTs have found application as transparent front contacts, and high work function back contacts in thin film solar PV. For the utility of SW-CNTs to be fully realized, however, controllable and stable doping as well as long term protection from doping must be achieved. Spectroscopic techniques facilitate detailed investigations of the intrinsic and variable properties of semiconductor materials without the issues of contact deposition and the possibility of sample contamination. Detailed spectroscopic analysis of the doping induced changes in the optical properties of SW-CNTs has revealed normally hidden excited state transitions in large diameter single walled carbon nanotubes for the first time. Spectroscopic monitoring of the degree of doping in SW-CNTs made possible studies of the dopant complex desorption and readsorption energies and kinetics. The long term protection from doping of SW-CNTs exposed to ambient laboratory conditions was achieved as a result of the more detailed understanding of the doping processes and mechanisms yielded by these spectroscopic studies. The application of SW-CNTs to other roles in solar PV devices was another goal of this research. Efficient collection of photogenerated charge carriers in semiconductor quantum dot (QD) based solar photovoltaic devices has been limited primarily by the poor transport properties and high density of recombination sites in the QD films. Coupling semiconductor QDs to nanomaterials with better transport properties is one potential solution to the poor transport within the QD films. This portion of the work investigated the possibility of charge transfer occurring in nano-heterostructures (NHSs) of PbS QDs and SW-CNTs produced through spontaneous self-assembly in solution. Electronic coupling in the form of charge transfer from the QDs to the SW-CNTs is unambiguously

  17. Single software platform used for high speed data transfer implementation in a 65k pixel camera working in single photon counting mode

    NASA Astrophysics Data System (ADS)

    Maj, P.; Kasiński, K.; Gryboś, P.; Szczygieł, R.; Kozioł, A.

    2015-12-01

    Integrated circuits designed for specific applications generally use non-standard communication methods. Hybrid pixel detector readout electronics produces a huge amount of data as a result of number of frames per seconds. The data needs to be transmitted to a higher level system without limiting the ASIC's capabilities. Nowadays, the Camera Link interface is still one of the fastest communication methods, allowing transmission speeds up to 800 MB/s. In order to communicate between a higher level system and the ASIC with a dedicated protocol, an FPGA with dedicated code is required. The configuration data is received from the PC and written to the ASIC. At the same time, the same FPGA should be able to transmit the data from the ASIC to the PC at the very high speed. The camera should be an embedded system enabling autonomous operation and self-monitoring. In the presented solution, at least three different hardware platforms are used—FPGA, microprocessor with real-time operating system and the PC with end-user software. We present the use of a single software platform for high speed data transfer from 65k pixel camera to the personal computer.

  18. Fluorescence resonance energy transfer on single living cells. Application to binding of monovalent haptens to cell-bound immunoglobulin E.

    PubMed Central

    Kubitscheck, U; Kircheis, M; Schweitzer-Stenner, R; Dreybrodt, W; Jovin, T M; Pecht, I

    1991-01-01

    We have determined the specific binding of 2,4-dinitrophenyl (DNP)-haptens to two different monoclonal immunoglobulin (IgE) molecules bound to Fc epsilon-receptors on the cell surface of single, living rat basophilic leukemia cells subclone 2H3 cells. The measurements were performed at 4 degrees, 15 degrees, and 25 degrees C using a recently developed technique that permits the quantitative determination of fluorescence resonance energy transfer between two fluorophores on single cells in a microscope from the photobleaching kinetics of the donor fluorophore. We introduce here a method for performing binding studies on individual attached cells. At 25 degrees C, the titration studies yielded equilibrium binding constants Kint of 9 x 10(8), 8 x 10(8), and 8 x 10(7) M-1 for the monovalent haptens N-2,4-DNP-epsilon-amino-n-caproic acid, N epsilon-2,4-DNP-L-lysine, and N-2,4-DNP-gamma-amino-n-butyric acid, respectively. Our data indicate that the affinity constants for the first two haptens binding to IgE on adherent cells are 4 to 11 times larger than that of the corresponding values obtained by fluorescence quenching experiments with the same haptens and IgE molecules either in solution or bound to cells in suspension. PMID:1832974

  19. Advanced maternal age causes adverse programming of mouse blastocysts leading to altered growth and impaired cardiometabolic health in post-natal life

    PubMed Central

    Velazquez, M.A.; Smith, C.G.C.; Smyth, N.R.; Osmond, C.; Fleming, T.P.

    2016-01-01

    STUDY QUESTION Does advanced maternal age (AMA) in mice affect cardiometabolic health during post-natal life in offspring derived from an assisted reproduction technology (ART) procedure? SUMMARY ANSWER Offspring derived from blastocysts collected from aged female mice displayed impaired body weight gain, blood pressure, glucose metabolism and organ allometry during post-natal life compared with offspring derived from blastocysts from young females; since all blastocysts were transferred to normalized young mothers, this effect is independent of maternal pregnancy conditions. WHAT IS KNOWN ALREADY Although studies in mice have shown that AMA can affect body weight and behaviour of offspring derived from natural reproduction, data on the effects of AMA on offspring cardiometabolic health during post-natal development are not available. Given the increasing use of ART to alleviate infertility in women of AMA, it is pivotal to develop ART–AMA models addressing the effects of maternal aging on offspring health. STUDY DESIGN, SIZE, DURATION Blastocysts from old (34–39 weeks) or young (8–9 weeks) C57BL/6 females mated with young CBA males (13–15 weeks) were either subjected to differential cell staining (inner cell mass and trophectoderm) or underwent embryo transfer (ET) into young MF1 surrogates (8–9 weeks) to produce young (Young-ET, 9 litters) and old (Old-ET, 10 litters) embryo-derived offspring. Offspring health monitoring was carried out for 30 weeks. PARTICIPANTS/MATERIALS, SETTING, METHODS All animals were fed with standard chow. Blood pressure was measured at post-natal Weeks 9, 15 and 21, and at post-natal Week 30 a glucose tolerance test (GTT) was performed. Two days after the GTT mice were killed for organ allometry. Blastocyst cell allocation variables were evaluated by T-test and developmental data were analysed with a multilevel random effects regression model. MAIN RESULTS AND THE ROLE OF CHANCE The total number of cells in blastocysts from

  20. Prepubertal goat oocytes from large follicles result in similar blastocyst production and embryo ploidy than those from adult goats.

    PubMed

    Romaguera, R; Moll, X; Morató, R; Roura, M; Palomo, M J; Catalá, M G; Jiménez-Macedo, A R; Hammami, S; Izquierdo, D; Mogas, T; Paramio, M T

    2011-07-01

    Developmental competence of oocytes from prepubertal females is lower than those from adult females. Oocyte development competence is positively related to follicular diameter. Most of the follicles of prepubertal goat ovaries are smaller than 3 mm. The aim of this study was to compare oocytes of two follicle sizes (< 3 mm and ≥ 3 mm) from prepubertal goats with oocytes from adult goats in relation to their in vitro production and quality of blastocysts. Oocytes from prepubertal goats were obtained from slaughterhouse ovaries and selected according to the follicle diameter whereas oocytes from adult goats were recovered in vivo by LOPU technique without prior selection of follicle size. COCs were IVM for 27 h, IVF at the conventional conditions with fresh semen and presumptive zygotes were cultured in SOF medium for 8 days. Blastocysts obtained were vitrified and after warming their blastocoele re-expansion and the ploidy by FISH technique were assessed. We found significant differences between blastocysts yield of oocytes recovered from follicles smaller than 3 mm of prepubertal goats compared to those from adult goats (5.45% vs 20. 83%, respectively) however, these differences disappear if oocytes were recovered form large follicles (18.07%). A total of 28 blastocysts were analysed and 96.43% showed mixoploidy. Age did not affect the number of embryos with abnormal ploidy or blastocyst re-expansion after warming. Furthermore, the percentage of diploid blastomeres per embryo was similar in the 3 groups studied, adult, prepubertal from follicles ≥ 3 mm and < 3 mm (68.6%, 80.8% and 73.6%, respectively). In conclusion, IVP of blastocysts coming from follicles larger than 3 mm of goats 45 days old were not different to the blastocysts produced from adult goats, both in terms of quantity and quality.

  1. Post-fusion treatment with MG132 increases transcription factor expression in somatic cell nuclear transfer embryos in pigs.

    PubMed

    You, Jinyoung; Lee, Joohyeong; Kim, Jinyoung; Park, Junhong; Lee, Eunsong

    2010-02-01

    The objective of this study was to examine the effect of post-fusion treatment of somatic cell nuclear transfer (SCNT) oocytes with the proteasomal inhibitor MG132 on maturation promoting factor (MPF) activity, nuclear remodeling, embryonic development, and gene expression of cloned pig embryos. Immediately after electrofusion, SCNT oocytes were treated with MG132 and/or caffeine for 2 hr, vanadate for 0.5 hr, or vanadate for 0.5 hr followed by MG132 for 1.5 hr. Of the MG132 concentrations tested (0-5 microM), the 1 microM concentration showed a higher rate of blastocyst formation (25.9%) than 0 (14.2%), 0.5 (16.9%), and 5 microM (16.9%). Post-fusion treatment with MG132, caffeine, and both MG132 and caffeine improved blastocyst formation (22.1%, 21.4%, and 24.4%, respectively), whereas vanadate treatment inhibited blastocyst formation (6.5%) compared to the control (11.1%). When examined 2 hr after fusion and 1 hr after activation, MPF activity remained at a higher (P < 0.05) level in SCNT oocytes that were treated post-fusion with caffeine and/or MG132, but it was decreased by vanadate. The rate of oocytes showing premature chromosome condensation was not altered by MG132 but was decreased by vanadate treatment. In addition, formation of single pronuclei was increased by MG132 compared to control and vanadate treatment. MG132-treated embryos showed increased expression of POU5F1, DPPA2, DPPA3, DPPA5, and NDP52l1 genes compared to control embryos. Our results demonstrate that post-fusion treatment of SCNT oocytes with MG132 prevents MPF degradation and increases expression of transcription factors in SCNT embryos, which are necessary for normal development of SCNT embryos.

  2. Relationship of serum elastin peptide level to single breath transfer factor for carbon monoxide in French coal miners

    PubMed Central

    Frette, C.; Jacob, M. P.; Wei, S. M.; Bertrand, J. P.; Laurent, P.; Kauffmann, F.; Pham, Q. T.

    1997-01-01

    BACKGROUND: Clinical and epidemiological studies have given discordant results on the usefulness of the level of circulating elastin peptide (EP), a potential marker of both elastin destruction (a key phenomenon in pulmonary emphysema) and neosynthesis, for assessing structural changes in the lung extracellular matrix. The aim of the present study was to explore the relationship between levels of EP and forced expiratory volume in one second (FEV1) and single breath transfer factor for carbon monoxide (TLCO and KCO) in coal miners. METHODS: The study population comprised 227 working coal miners aged 34-50 years consisting of 75 miners heavily exposed to underground coal dust with pulmonary radiographs classified as 0/1 or 1/0 by the International Labour Office classification, 75 exposed miners with radiographs classified as normal (0/0), and 77 miners slightly exposed to coal dust with normal radiographs. The subjects answered a standardised questionnaire and performed spirometric tests and a carbon monoxide (CO) transfer test. RESULTS: No association was observed between EP levels and % predicted FEV1 (or FEV1/FVC). The level of EP increased significantly with decreased % predicted TLCO (r = -0.20). Miners in the lowest % predicted KCO quintile had higher EP levels than the rest (3.28 (1.37) vs 2.47 (1.16)). A significantly lower EP level was observed in miners with radiographs classified as 1/0 or 0/1, especially in those with round opacities, compared with miners with a normal radiograph, and in current smokers compared with the rest. CONCLUSIONS: The results of this study suggest that the level of EP may reflect some remodelling activity in emphysema and lung fibrosis. 


 PMID:9516897

  3. Introducing a single-cell-derived human mesenchymal stem cell line expressing hTERT after lentiviral gene transfer.

    PubMed

    Böcker, Wolfgang; Yin, Zhanhai; Drosse, Inga; Haasters, Florian; Rossmann, Oliver; Wierer, Matthias; Popov, Cvetan; Locher, Melanie; Mutschler, Wolf; Docheva, Denitsa; Schieker, Matthias

    2008-08-01

    Human mesenchymal stem cells (hMSCs) can be readily isolated from bone marrow and differentiate into multiple tissues, making them a promising target for future cell and gene therapy applications. The low frequency of hMSCs in bone marrow necessitates their isolation and expansion in vitro prior to clinical use, but due to senescence-associated growth arrest during culture, limited cell numbers can be generated. The lifespan of hMSCs has been extended by ectopic expression of human telomerase reverse transcriptase (hTERT) using retroviral vectors. Since malignant transformation was observed in hMSCs and retroviral vectors cause insertional mutagenesis, we ectopically expressed hTERT using lentiviral gene transfer. Single-cell-derived hMSC clones expressing hTERT did not show malignant transformation in vitro and in vivo after extended culture periods. There were no changes observed in the expression of tumour suppressor genes and karyotype. Cultured hMSCs lack telomerase activity, but it was significantly increased by ectopic expression of hTERT. HTERT expression prevented hMSC senescence and the cells showed significantly higher and unlimited proliferation capacity. Even after an extended culture period, hMSCs expressing hTERT preserved their stem cells character as shown by osteogenic, adipogenic and chondrogenic differentiation. In summary, extending the lifespan of human mesenchymal stem cells by ectopic expression of hTERT using lentiviral gene transfer may be an attractive and safe way to generate appropriate cell numbers for cell and gene therapy applications.

  4. Chirality transfer from a single chiral molecule to 2D superstructures in alaninol on the Cu(100) surface.

    PubMed

    Contini, G; Gori, P; Ronci, F; Zema, N; Colonna, S; Aschi, M; Palma, A; Turchini, S; Catone, D; Cricenti, A; Prosperi, T

    2011-06-21

    The formation of 2D chiral monolayers obtained by self-assembly of chiral molecules on surfaces has been widely reported in the literature. Control of chirality transfer from a single molecule to surface superstructures is a challenging and important aspect for tailoring the properties of 2D nanostructures. However, despite the wealth of investigations performed in recent years, how chiral transfer takes place on a large scale still remains an open question. In this paper we report a coupling of scanning tunneling microscopy and low energy electron diffraction measurements with an original theoretical approach, combining molecular dynamics and essential dynamics with density functional theory, to investigate self-assembled chiral structures formed when alaninol adsorbs on Cu(100). The peculiarity of this system is related to the formation of tetrameric molecular structures which constitute the building blocks of the self-assembled chiral monolayer. Such characteristics make alaninol/Cu(100) a good candidate to reveal chiral expression changes. We find that the deposition of alaninol enantiomers results in the formation of isolated tetramers that are aligned along the directions of the substrate at low coverage or when geometrical confinement prevents long-range order. Conversely, a rotation of 14° with respect to the Cu(100) unit vectors is observed when small clusters of tetramers are formed. An insight to the process leading to a 2D globally chiral surface has been obtained by monitoring molecular assemblies as they grow from the early stages of adsorption, suggesting that the distinctive orientation of the self-assembled monolayer originates from a balance of cooperating forces which start acting only when tetramers pack together to form small clusters.

  5. Postthaw survival of in vitro-produced bovine blastocysts loaded onto the inner surface of a plastic vitrification straw.

    PubMed

    Ha, A-Na; Park, Han-Seul; Jin, Jong-In; Lee, Sang-Ho; Ko, Dae-Hwan; Lee, Dong-Suk; White, Kenneth L; Kong, Il-Keun

    2014-02-01

    In this study, we investigated whether vitrification of an embryo by attachment to the inner surface of a plastic straw, which requires a small volume of vitrification solution, improves the survival of thawed embryos. In vitro-produced Korean native cattle blastocysts were randomly assigned into four groups: (1) blastocysts attached to the inner surface of a plastic straw (aV); (2) blastocysts loaded into the column of a plastic straw (cV); (3) blastocysts directly dropped into liquid nitrogen (dV); and (4) nonvitrified blastocysts (control). The postthaw recovery rate did not significantly differ among the aV, dV, and cV groups (98.3% vs. 81.5% vs. 91.4%). The postthaw survival rate was greater in the control, aV, and dV groups than in the cV group (100%, 87.7%, and 81.8% vs. 26.4%, P < 0.05), but did not significantly differ among the control, aV, and dV groups. The total number of cells per blastocyst did not significantly differ among the groups (134.4 ± 38.9 in control vs. 114 ± 48.1 in aV, 105.6 ± 33.9 in dV, and 102 ± 35.1 in cV group). However, the number of apoptotic cells per blastocyst was higher in the dV and cV groups than in the control group (10.9 ± 9.6 and 14.5 ± 9.5 vs. 0.4 ± 1.4; P < 0.05), but did not significantly differ between the control and aV groups (0.4 ± 1.4 vs. 6.6 ± 9.5). In addition, the blastocoel of each blastocyst was left intact or was mechanically punctured to reduce its volume, and the blastocysts were then vitrified using the aV method. At 12 hours after thawing, the re-expansion rate did not significantly differ among the control, punctured aV, and nonpunctured aV groups (93.3% vs. 85.2% vs. 82.8%). However, at 24 hours after thawing, the hatching rate was greater in the control and punctured aV groups than in the nonpunctured aV group (75% and 62.9% vs. 37.1%; P < 0.05). The total number of cells per blastocyst was greater in the control group than in the nonpunctured aV group (143 ± 37.2 vs. 94.5 ± 18.6; P < 0

  6. Comparison of blastocyst and Sage media for in vitro maturation of human immature oocytes.

    PubMed

    Pongsuthirak, Pallop; Songveeratham, Sorramon; Vutyavanich, Teraporn

    2015-03-01

    In vitro maturation (IVM) of human oocytes is an attractive alternative to conventional assisted reproductive technology (ART) treatment, as it involves no or minimal ovarian stimulation. Currently, commercialized media specifically designed for IVM are often used. These media are expensive, have limited shelf life, and must be ordered in advance. If standard culture media can be used in place of the specialized IVM media, it would simplify management and make IVM more feasible and more widely employed in ART centers around the world, especially in developing countries where resources are scarce. This study was, therefore, conducted to test the hypothesis that blastocyst medium was as good as commercial IVM medium to support maturation and developmental competence of human immature oocytes as previously shown in the mouse system. Immature oocytes were obtained by needle aspiration from 89 pregnant women during cesarean deliveries between April 2012 and February 2013. Sibling oocytes were allocated to Sage IVM media (512 oocytes) or blastocyst medium (520 oocytes) and assessed for maturation 36 hours later. Mature oocytes were inseminated by intracytoplasmic sperm injection and cultured up to 144 hours. There was no difference in maturation rate (65.0% vs 68.7%; P = .218) or fertilization rate (66.9% vs 66.4%; P = .872) of oocytes matured in vitro in both media. There was also no difference in the formation of good-quality blastocysts (46.6% vs 45.9%; P = .889) in the 2 groups. Further study should be done to ascertain implantation and pregnancy potential of these embryos.

  7. ROCK activity regulates functional tight junction assembly during blastocyst formation in porcine parthenogenetic embryos

    PubMed Central

    Kwon, Jeongwoo

    2016-01-01

    The Rho-associated coiled-coil-containing protein serine/threonine kinases 1 and 2 (ROCK1 and ROCK2) are Rho subfamily GTPase downstream effectors that regulate cell migration, intercellular adhesion, cell polarity, and cell proliferation by stimulating actin cytoskeleton reorganization. Inhibition of ROCK proteins affects specification of the trophectoderm (TE) and inner cell mass (ICM) lineages, compaction, and blastocyst cavitation. However, the molecules involved in blastocyst formation are not known. Here, we examined developmental competence and levels of adherens/tight junction (AJ/TJ) constituent proteins, such as CXADR, OCLN, TJP1, and CDH1, as well as expression of their respective mRNAs, after treating porcine parthenogenetic four-cell embryos with Y-27632, a specific inhibitor of ROCK, at concentrations of 0, 10, 20, 100 µM for 24 h. Following this treatment, the blastocyst development rates were 39.1, 20.7, 10.0, and 0% respectively. In embryos treated with 20 µM treatment, expression levels of CXADR, OCLN, TJP1, and CDH1 mRNA and protein molecules were significantly reduced (P < 0.05). FITC-dextran uptake assay revealed that the treatment caused an increase in TE TJ permeability. Interestingly, the majority of the four-cell and morula embryos treated with 20 µM Y-27643 for 24 h showed defective compaction and cavitation. Taken together, our results indicate that ROCK activity may differentially affect assembly of AJ/TJs as well as regulate expression of genes encoding junctional proteins. PMID:27077008

  8. Murine somatic cell nuclear transfer using reprogrammed donor cells expressing male germ cell-specific genes.

    PubMed

    Kang, Hoin; Park, Jong Im; Roh, Sangho

    2016-01-01

    In vivo-matured mouse oocytes were enucleated, and a single murine embryonic fibroblast (control or reprogrammed by introducing extracts from murine testis tissue, which showed expression of male germ cell-specific genes) was injected into the cytoplasm of the oocytes. The rate of blastocyst development and expression levels of Oct-4, Eomes and Cdx-2 were not significantly different in both experimental groups. However, the expression levels of Nanog, Sox9 and Glut-1 were significantly increased when reprogrammed cells were used as donor nuclei. Increased expression of Nanog can be supportive of complete reprogramming of somatic cell nuclear transfer murine embryos. The present study suggested that donor cells expressing male germ cell-specific genes can be reconstructed and can develop into embryos with normal high expression of developmentally essential genes.

  9. Effect of hyaluronan on developmental competence and quality of oocytes and obtained blastocysts from in vitro maturation of bovine oocytes.

    PubMed

    Opiela, Jolanta; Romanek, Joanna; Lipiński, Daniel; Smorąg, Zdzisław

    2014-01-01

    The objective of the present study was to evaluate the effect of hyaluronan (HA) during IVM on meiotic maturation, embryonic development, and the quality of oocytes, granulosa cells (GC), and obtained blastocysts. COCs were matured in vitro in control medium and medium with additional 0.035% or 0.07% of exogenous HA. The meiotic maturity did not differ between the analysed groups. The best rate and the highest quality of obtained blastocysts were observed when 0.07% HA was used. A highly significant difference (P < 0.001) was noted in the mean number of apoptotic nuclei per blastocyst and in the DCI between the 0.07% HA and the control blastocysts (P < 0.01). Our results suggest that addition of 0.035% HA and 0.07% HA to oocyte maturation media does not affect oocyte nuclear maturation and DNA fragmentation. However, the addition of 0.07% HA during IVM decreases the level of blastocysts DNA fragmentation. Finally, our results suggest that it may be risky to increase the HA concentration during IVM above 0.07% as we found significantly higher Bax mRNA expression levels in GC cultured with 0.07% HA. The final concentration of HA being supplemented to oocyte maturation media is critical for the success of the IVP procedure.

  10. Mouse embryo motion and embryonic development from the 2-cell to blastocyst stage using mechanical vibration systems.

    PubMed

    Asano, Yuka; Matsuura, Koji

    2014-06-01

    We investigated the effect of mechanical stimuli on mouse embryonic development from the 2-cell to blastocyst stage to evaluate physical factors affecting embryonic development. Shear stress (SS) applied to embryos using two mechanical vibration systems (MVSs) was calculated by observing microscopic images of moving embryos during mechanical vibration (MV). The MVSs did not induce any motion of the medium and the diffusion rate using MVSs was the same as that under static conditions. Three days of culture using MVS did not improve embryonic development. MVS transmitted MV power more efficiently to embryos than other systems and resulted in a significant decrease in development to the morula or blastocyst stage after 2 days. Comparison of the results of embryo culture using dynamic culture systems demonstrated that macroscopic diffusion of secreted materials contributes to improved development of mouse embryos to the blastocyst stage. These results also suggest that the threshold of SS and MV to induce negative effects for mouse embryos at stages earlier than the blastocyst may be lower than that for the blastocyst, and that mouse embryos are more sensitive to physical and chemical stimuli than human or pig embryos because of their thinner zona pellucida.

  11. The performance of single- and multi-proxy transfer functions (testate amoebae, bryophytes, vascular plants) for reconstructing mire surface wetness and pH

    NASA Astrophysics Data System (ADS)

    Mitchell, Edward A. D.; Payne, Richard J.; van der Knaap, Willem O.; Lamentowicz, Łukasz; Gąbka, Maciej; Lamentowicz, Mariusz

    2013-01-01

    Peatlands are widely exploited archives of paleoenvironmental change. We developed and compared multiple transfer functions to infer peatland depth to the water table (DWT) and pH based on testate amoeba (percentages, or presence/absence), bryophyte presence/absence, and vascular plant presence/absence data from sub-alpine peatlands in the SE Swiss Alps in order to 1) compare the performance of single-proxy vs. multi-proxy models and 2) assess the performance of presence/absence models. Bootstrapping cross-validation showing the best performing single-proxy transfer functions for both DWT and pH were those based on bryophytes. The best performing transfer functions overall for DWT were those based on combined testate amoebae percentages, bryophytes and vascular plants; and, for pH, those based on testate amoebae and bryophytes. The comparison of DWT and pH inferred from testate amoeba percentages and presence/absence data showed similar general patterns but differences in the magnitude and timing of some shifts. These results show new directions for paleoenvironmental research, 1) suggesting that it is possible to build good-performing transfer functions using presence/absence data, although with some loss of accuracy, and 2) supporting the idea that multi-proxy inference models may improve paleoecological reconstruction. The performance of multi-proxy and single-proxy transfer functions should be further compared in paleoecological data.

  12. Controlled synthesis and transfer of large-area WS2 sheets: from single layer to few layers.

    PubMed

    Elías, Ana Laura; Perea-López, Néstor; Castro-Beltrán, Andrés; Berkdemir, Ayse; Lv, Ruitao; Feng, Simin; Long, Aaron D; Hayashi, Takuya; Kim, Yoong Ahm; Endo, Morinobu; Gutiérrez, Humberto R; Pradhan, Nihar R; Balicas, Luis; Mallouk, Thomas E; López-Urías, Florentino; Terrones, Humberto; Terrones, Mauricio

    2013-06-25

    The isolation of few-layered transition metal dichalcogenides has mainly been performed by mechanical and chemical exfoliation with very low yields. In this account, a controlled thermal reduction-sulfurization method is used to synthesize large-area (~1 cm(2)) WS2 sheets with thicknesses ranging from monolayers to a few layers. During synthesis, WOx thin films are first deposited on Si/SiO2 substrates, which are then sulfurized (under vacuum) at high temperatures (750-950 °C). An efficient route to transfer the synthesized WS2 films onto different substrates such as quartz and transmission electron microscopy (TEM) grids has been satisfactorily developed using concentrated HF. Samples with different thicknesses have been analyzed by Raman spectroscopy and TEM, and their photoluminescence properties have been evaluated. We demonstrated the presence of single-, bi-, and few-layered WS2 on as-grown samples. It is well known that the electronic structure of these materials is very sensitive to the number of layers, ranging from indirect band gap semiconductor in the bulk phase to direct band gap semiconductor in monolayers. This method has also proved successful in the synthesis of heterogeneous systems of MoS2 and WS2 layers, thus shedding light on the controlled production of heterolayered devices from transition metal chalcogenides.

  13. A novel peptide delivers plasmids across blood-brain barrier into neuronal cells as a single-component transfer vector.

    PubMed

    Fu, Ailing; Zhang, Miaomiao; Gao, Feiyan; Xu, Xingran; Chen, Zhangbao

    2013-01-01

    There is no data up to now to show that peptide can deliver plasmid into brain as a single-component transfer vector. Here we show that a novel peptide, RDP (consisted of 39 amino acids), can be exploited as an efficient plasmid vector for brain-targeting delivery. The plasmids containing Lac Z reporter gene (pVAX-Lac Z) and BDNF gene (pVAX-BDNF) are complexed with RDP and intravenously injected into mice. The results of gel retardation assay show that RDP enables to bind DNA in a dose-dependent manner, and the X-Gal staining identity that Lac Z is specifically expressed in the brain. Also, the results of Western blot and immunofluorescence staining of BDNF indicate that pVAX-BDNF complexed with RDP can be delivered into brain, and show neuroprotective properties in experimental Parkinson's disease (PD) model. The results demonstrate that RDP enables to bind and deliver DNA into the brain, resulting in specific gene expression in the neuronal cells. This strategy provides a novel, simple and effective approach for non-viral gene therapy of brain diseases.

  14. Charge transfer of single laser crystallized intrinsic and phosphorus-doped Si-nanocrystals visualized by Kelvin probe force microscopy

    SciTech Connect

    Xu, Jie; Xu, Jun Lu, Peng; Shan, Dan; Li, Wei; Chen, Kunji

    2014-10-07

    Isolated intrinsic and phosphorus doped (P-doped) Si-nanocrystals (Si-NCs) on n- and p-Si substrates are fabricated by excimer laser crystallization techniques. The formation of Si-NCs is confirmed by atomic force microscopy (AFM) and conductive AFM measurements. Kelvin probe force microscopy (KPFM) is then carried out to visualize the trapped charges in a single Si-NC dot which derives from the charge transfer between Si-NCs and Si substrates due to their different Fermi levels. The laser crystallized P-doped Si-NCs have a similar Fermi level around the mid-gap to the intrinsic counterparts, which might be caused by the inactivated impurity atoms or the surface states-related Fermi level pinning. A clear rise of the Fermi level in P-doped Si-NCs is observed after a short time thermal annealing treatment, indicating the activation of dopants in Si-NCs. Moreover, the surface charge quantity can be estimated using a simple parallel plate capacitor model for a quantitative understanding of the KPFM results at the nanoscale.

  15. Self-Assembled Colloidal Particle Clusters from In Situ Pickering-Like Emulsion Polymerization via Single Electron Transfer Mechanism.

    PubMed

    Yuan, Jinfeng; Zhao, Weiting; Pan, Mingwang; Zhu, Lei

    2016-08-01

    A simple route is reported to synthesize colloidal particle clusters (CPCs) from self-assembly of in situ poly(vinylidene fluoride)/poly(styrene-co-tert-butyl acrylate) [PVDF/P(St-co-tBA)] Janus particles through one-pot seeded emulsion single electron transfer radical polymerization. In the in situ Pickering-like emulsion polymerization, the tBA/St/PVDF feed ratio and polymerization temperature are important for the formation of well-defined CPCs. When the tBA/St/PVDF feed ratio is 0.75 g/2.5 g/0.5 g and the reaction temperature is 35 °C, relatively uniform raspberry-like CPCs are obtained. The hydrophobicity of the P(St-co-tBA) domains and the affinity of PVDF to the aqueous environment are considered to be the driving force for the self-assembly of the in situ formed PVDF/P(St-co-tBA) Janus particles. The resultant raspberry-like CPCs with PVDF particles protruding outward may be promising for superhydrophobic smart coatings.

  16. IVF with planned single-embryo transfer versus IUI with ovarian stimulation in couples with unexplained subfertility: an economic analysis.

    PubMed

    van Rumste, Minouche M E; Custers, Inge M; van Wely, Madelon; Koks, Carolien A; van Weering, Hans G I; Beckers, Nicole G M; Scheffer, Gabrielle J; Broekmans, Frank J M; Hompes, Peter G A; Mochtar, Monique H; van der Veen, Fulco; Mol, Ben W J

    2014-03-01

    Couples with unexplained subfertility are often treated with intrauterine insemination (IUI) with ovarian stimulation, which carries the risk of multiple pregnancies. An explorative randomized controlled trial was performed comparing one cycle of IVF with elective single-embryo transfer (eSET) versus three cycles of IUI-ovarian stimulation in couples with unexplained subfertility and a poor prognosis for natural conception, to assess the economic burden of the treatment modalities. The main outcome measures were ongoing pregnancy rates and costs. This study randomly assigned 58 couples to IVF-eSET and 58 couples to IUI-ovarian stimulation. The ongoing pregnancy rates were 24% in with IVF-eSET versus 21% with IUI-ovarian stimulation, with two and three multiple pregnancies, respectively. The mean cost per included couple was significantly different: €2781 with IVF-eSET and €1876 with IUI-ovarian stimulation (P<0.01). The additional costs per ongoing pregnancy were €2456 for IVF-eSET. In couples with unexplained subfertility, one cycle of IVF-eSET cost an additional €900 per couple compared with three cycles of IUI-ovarian stimulation, for no increase in ongoing pregnancy rates or decrease in multiple pregnancies. When IVF-eSET results in higher ongoing pregnancy rates, IVF would be the preferred treatment. Couples that have been trying to conceive unsuccessfully are often treated with intrauterine insemination (IUI) and medication to improve egg production (ovarian stimulation). This treatment carries the risk of multiple pregnancies like twins. We performed an explorative study among those couples that had a poor prognosis for natural conception. One cycle of IVF with transfer of one selected embryo (elective single-embryo transfer, eSET) was compared with three cycles of IUI-ovarian stimulation. The aim of this study was to assess the economic burden of both treatments. The Main outcome measures were number of good pregnancies above 12weeks and costs. We

  17. Differential expression of ezrin/radixin/moesin (ERM) and ERM-associated adhesion molecules in the blastocyst and uterus suggests their functions during implantation.

    PubMed

    Matsumoto, Hiromichi; Daikoku, Takiko; Wang, Haibin; Sato, Eimei; Dey, S K

    2004-03-01

    Development of the blastocyst to implantation competency, differentiation of the uterus to the receptive state, and a cross talk between the implantation-competent blastocyst and the uterine luminal epithelium are all essential to the process of implantation. In the present investigation, we examined the possibility for a potential cross talk between the blastocyst and uterus involving the ezrin/radixin/moesin (ERM) proteins and ERM-associated cytoskeletal cross-linker proteins CD43, CD44, ICAM-1, and ICAM-2. In normal Day 4 blastocysts and after rendering dormant blastocysts to implantation-competent by estrogen in vivo (activated), the outer surface of mural trophectoderm cells showed much higher levels of radixin as compared to those in the polar trophectoderm cells, inner cell mass (ICM), and primitive endoderm. In contrast, ezrin was present on both the mural and the polar trophectoderm cell surfaces of normal Day 4 and activated blastocysts at higher intensity than dormant blastocysts. A distinct localization was noted in the primitive endoderm of dormant blastocysts that was not apparent in activated or normal Day 4 blastocysts. The expression of moesin was modestly higher at the mural trophectoderm of implantation-competent blastocysts, while the localization appeared to be present primarily on the polar trophectoderm cell surface of Day 4 blastocysts. The localization of ERM-associated adhesion molecules CD43, CD44, and ICAM-2 was more intense in the implantation-competent blastocysts compared with the dormant blastocysts. However, while CD44 was present both in the trophectoderm and in ICM, CD43 and ICAM-2 were localized primarily to the trophectoderm. The signal for ICAM-1 was very intense in the ICM but was modest in the trophectoderm. No significant changes in fluorescence intensity were noted between activated and dormant blastocysts. In the receptive uterus on Day 4 of pregnancy, ERM proteins were localized to the uterine epithelium, while on Day 5

  18. Is There a Link Between Expression Levels of Histone Deacetylase/Acetyltransferase in Mouse Sperm and Subsequent Blastocyst Development?

    PubMed

    Kim, Jayeon; Kim, Ji-Hee; Jee, Byung-Chul; Suh, Chang-Suk; Kim, Seok-Hyun

    2015-11-01

    Histone acetylation has been known to be significant in spermatogenesis. Histone acetylation is regulated by the act of histone deacetylases (HDACs) and histone acetyltransferases (HATs). We investigated the link between expression levels of HDACs and HATs in mouse sperm and subsequent blastocyst formation rate. In the univariate analysis, expression levels of HDAC1 and HAT were generally not associated with the blastocyst formation rate. When divided by the mature oocyte number category, a significant positive association was observed between the expression levels of HDAC1 and the blastocyst-forming rate in the highest (> 75th) percentile group (a group with ≥34 mature oocytes). In conclusion, expression of sperm HDAC1 could be considered as a possible predictor of embryo development in mice with high ovarian response.

  19. A High-yield Two-step Transfer Printing Method for Large-scale Fabrication of Organic Single-crystal Devices on Arbitrary Substrates

    PubMed Central

    Deng, Wei; Zhang, Xiujuan; Pan, Huanhuan; Shang, Qixun; Wang, Jincheng; Zhang, Xiaohong; Zhang, Xiwei; Jie, Jiansheng

    2014-01-01

    Single-crystal organic nanostructures show promising applications in flexible and stretchable electronics, while their applications are impeded by the large incompatibility with the well-developed photolithography techniques. Here we report a novel two-step transfer printing (TTP) method for the construction of organic nanowires (NWs) based devices onto arbitrary substrates. Copper phthalocyanine (CuPc) NWs are first transfer-printed from the growth substrate to the desired receiver substrate by contact-printing (CP) method, and then electrode arrays are transfer-printed onto the resulting receiver substrate by etching-assisted transfer printing (ETP) method. By utilizing a thin copper (Cu) layer as sacrificial layer, microelectrodes fabricated on it via photolithography could be readily transferred to diverse conventional or non-conventional substrates that are not easily accessible before with a high transfer yield of near 100%. The ETP method also exhibits an extremely high flexibility; various electrodes such as Au, Ti, and Al etc. can be transferred, and almost all types of organic devices, such as resistors, Schottky diodes, and field-effect transistors (FETs), can be constructed on planar or complex curvilinear substrates. Significantly, these devices can function properly and exhibit closed or even superior performance than the device counterparts fabricated by conventional approach. PMID:24942458

  20. Gene Expression Noise Enhances Robust Organization of the Early Mammalian Blastocyst

    PubMed Central

    Wang, Qixuan; Du, Huijing; Peng, Tao; Chiang, Michael; Cinquin, Olivier; Cho, Ken

    2017-01-01

    A critical event in mammalian embryo development is construction of an inner cell mass surrounded by a trophoectoderm (a shell of cells that later form extraembryonic structures). We utilize multi-scale, stochastic modeling to investigate the design principles responsible for robust establishment of these structures. This investigation makes three predictions, each supported by our quantitative imaging. First, stochasticity in the expression of critical genes promotes cell plasticity and has a critical role in accurately organizing the developing mouse blastocyst. Second, asymmetry in the levels of noise variation (expression fluctuation) of Cdx2 and Oct4 provides a means to gain the benefits of noise-mediated plasticity while ameliorating the potentially detrimental effects of stochasticity. Finally, by controlling the timing and pace of cell fate specification, the embryo temporally modulates plasticity and creates a time window during which each cell can continually read its environment and adjusts its fate. These results suggest noise has a crucial role in maintaining cellular plasticity and organizing the blastocyst. PMID:28114387

  1. Inhibition of Fatty Acid Synthase Reduces Blastocyst Hatching through Regulation of the AKT Pathway in Pigs

    PubMed Central

    Guo, Jing; Kim, Nam-Hyung; Cui, Xiang-Shun

    2017-01-01

    Fatty acid synthase (FASN) is an enzyme responsible for the de novo synthesis of long-chain fatty acids. During oncogenesis, FASN plays a role in growth and survival rather than acting within the energy storage pathways. Here, the function of FASN during early embryonic development was studied using its specific inhibitor, C75. We found that the presence of the inhibitor reduced blastocyst hatching. FASN inhibition decreased Cpt1 expression, leading to a reduction in mitochondria numbers and ATP content. This inhibition of FASN resulted in the down-regulation of the AKT pathway, thereby triggering apoptosis through the activation of the p53 pathway. Activation of the apoptotic pathway also leads to increased accumulation of reactive oxygen species and autophagy. In addition, the FASN inhibitor impaired cell proliferation, a parameter of blastocyst quality for outgrowth. The level of OCT4, an important factor in embryonic development, decreased after treatment with the FASN inhibitor. These results show that FASN exerts an effect on early embryonic development by regulating both fatty acid oxidation and the AKT pathway in pigs. PMID:28107461

  2. Transcriptome Profiling of Rabbit Parthenogenetic Blastocysts Developed under In Vivo Conditions

    PubMed Central

    Naturil-Alfonso, Carmen; Saenz-de-Juano, María dels Desamparats; Peñaranda, David S.

    2012-01-01

    Parthenogenetic embryos are one attractive alternative as a source of embryonic stem cells, although many aspects related to the biology of parthenogenetic embryos and parthenogenetically derived cell lines still need to be elucidated. The present work was conducted to investigate the gene expression profile of rabbit parthenote embryos cultured under in vivo conditions using microarray analysis. Transcriptomic profiles indicate 2541 differentially expressed genes between parthenotes and normal in vivo fertilised blastocysts, of which 76 genes were upregulated and 16 genes downregulated in in vivo cultured parthenote blastocyst, using 3 fold-changes as a cut-off. While differentially upregulated expressed genes are related to transport and protein metabolic process, downregulated expressed genes are related to DNA and RNA binding. Using microarray data, 6 imprinted genes were identified as conserved among rabbits, humans and mice: GRB10, ATP10A, ZNF215, NDN, IMPACT and SFMBT2. We also found that 26 putative genes have at least one member of that gene family imprinted in other species. These data strengthen the view that a large fraction of genes is differentially expressed between parthenogenetic and normal embryos cultured under the same conditions and offer a new approach to the identification of imprinted genes in rabbit. PMID:23251477

  3. Comparison of Cryotop and micro volume air cooling methods for cryopreservation of bovine matured oocytes and blastocysts

    PubMed Central

    PUNYAWAI, Kanchana; ANAKKUL, Nitira; SRIRATTANA, Kanokwan; AIKAWA, Yoshio; SANGSRITAVONG, Siwat; NAGAI, Takashi; IMAI, Kei; PARNPAI, Rangsun

    2015-01-01

    This study was designed to compare the efficiency of the Cryotop method and that of two methods that employ a micro volume air cooling (MVAC) device by analyzing the survival and development of bovine oocytes and blastocysts vitrified using each method. In experiment I, in vitro-matured (IVM) oocytes were vitrified using an MVAC device without direct contact with liquid nitrogen (LN2; MVAC group) or directly plunged into LN2 (MVAC in LN2 group). A third group of IVM oocytes was vitrified using a Cryotop device (Cryotop group). After warming, vitrified oocytes were fertilized in vitro. There were no significant differences in cleavage and blastocyst formation rates among the three vitrified groups, with the rates ranging from 53.1% to 56.6% and 20.0% to 25.5%, respectively; however, the rates were significantly lower (P < 0.05) than those of the fresh control group (89.3% and 43.3%, respectively) and the solution control group (87.3% and 42.0%, respectively). In experiment II, in vitro-produced (IVP) expanded blastocysts were vitrified using the MVAC, MVAC in LN2 and Cryotop methods, warmed and cultured for survival analysis and then compared with the solution control group. The rate of development of vitrified-warmed expanded blastocysts to the hatched blastocyst stage after 24 h of culture was lower in the MVAC in LN2 group than in the solution control group; however, after 48–72 h of culture, the rates did not significantly differ between the groups. These results indicate that the MVAC method without direct LN2 contact is as effective as the standard Cryotop method for vitrification of bovine IVM oocytes and IVP expanded blastocysts. PMID:26119929

  4. Comparison of Cryotop and micro volume air cooling methods for cryopreservation of bovine matured oocytes and blastocysts.

    PubMed

    Punyawai, Kanchana; Anakkul, Nitira; Srirattana, Kanokwan; Aikawa, Yoshio; Sangsritavong, Siwat; Nagai, Takashi; Imai, Kei; Parnpai, Rangsun

    2015-01-01

    This study was designed to compare the efficiency of the Cryotop method and that of two methods that employ a micro volume air cooling (MVAC) device by analyzing the survival and development of bovine oocytes and blastocysts vitrified using each method. In experiment I, in vitro-matured (IVM) oocytes were vitrified using an MVAC device without direct contact with liquid nitrogen (LN2; MVAC group) or directly plunged into LN2 (MVAC in LN2 group). A third group of IVM oocytes was vitrified using a Cryotop device (Cryotop group). After warming, vitrified oocytes were fertilized in vitro. There were no significant differences in cleavage and blastocyst formation rates among the three vitrified groups, with the rates ranging from 53.1% to 56.6% and 20.0% to 25.5%, respectively; however, the rates were significantly lower (P < 0.05) than those of the fresh control group (89.3% and 43.3%, respectively) and the solution control group (87.3% and 42.0%, respectively). In experiment II, in vitro-produced (IVP) expanded blastocysts were vitrified using the MVAC, MVAC in LN2 and Cryotop methods, warmed and cultured for survival analysis and then compared with the solution control group. The rate of development of vitrified-warmed expanded blastocysts to the hatched blastocyst stage after 24 h of culture was lower in the MVAC in LN2 group than in the solution control group; however, after 48-72 h of culture, the rates did not significantly differ between the groups. These results indicate that the MVAC method without direct LN2 contact is as effective as the standard Cryotop method for vitrification of bovine IVM oocytes and IVP expanded blastocysts.

  5. Fusion of blastomeres in mouse embryos under the action of femtosecond laser radiation. Efficiency of blastocyst formation and embryo development

    NASA Astrophysics Data System (ADS)

    Osychenko, A. A.; Zalesskii, A. D.; Krivokharchenko, A. S.; Zhakhbazyan, A. K.; Ryabova, A. V.; Nadtochenko, V. A.

    2015-05-01

    Using the method of femtosecond laser surgery we study the fusion of two-cell mouse embryos under the action of tightly focused femtosecond laser radiation with the fusion efficiency reaching 60%. The detailed statistical analysis of the efficiency of blastomere fusion and development of the embryo up to the blastocyst stage after exposure of the embryos from different mice to a femtosecond pulse is presented. It is shown that the efficiency of blastocyst formation essentially depends on the biological characteristics of the embryo, namely, the strain and age of the donor mouse. The possibility of obtaining hexaploid embryonal cells using the methods of femtosecond laser surgery is demonstrated.

  6. Light-independent reactive oxygen species (ROS) formation through electron transfer from carboxylated single-walled carbon nanotubes in water.

    PubMed

    Hsieh, Hsin-Se; Wu, Renren; Jafvert, Chad T

    2014-10-07

    Promising developments in application of carbon nanotubes (CNTs) have raised concern regarding potential biological and environmental effects upon their inevitable release to the environment. Although some CNTs have been reported to generate reactive oxygen species (ROS) under light, limited information exists on ROS generation by these materials in the dark. In this study, generation of ROS was examined, initiated by electron transfer from biological electron donors through carboxylated single-walled carbon nanotubes (C-SWCNT) to molecular oxygen in water in the dark. In the presence of C-SWCNT, the oxidation of NADH (β-nicotinamide adenine dinucleotide, reduced form) and DTTre (DL-dithiothreitol, reduced form) was confirmed by light absorbance shifts (340 nm to 260 nm during oxidation of NADH to NAD(+), and increased light absorbance at 280 nm during oxidation of DTTre). Production of superoxide anion (O2(•-)) was detected by its selective reaction with a tetrazolium salt (NBT(2+)), forming a formazan product that is visible at 530 nm. A modified acid-quenched N,N-diethyl-p-phenylenediamine (DPD) assay was used to measure the accumulation of H2O2 in C-SWCNT suspensions containing O2 and NADH. In the same suspensions (i.e., containing C-SWCNT, NADH, and O2), pBR322 DNA plasmid was cleaved, although •OH was not detected when using •OH scavenging molecular probes. These results indicate that the oxidation of electron donors by C-SWCNT can be a light-independent source of ROS in water, and that electron shuttling through CNTs to molecular oxygen may be a potential mechanism for DNA damage by this specific CNT and potentially other carbon-based nanomaterials.

  7. Modelling and optimization of transient processes in line focusing power plants with single-phase heat transfer medium

    NASA Astrophysics Data System (ADS)

    Noureldin, K.; González-Escalada, L. M.; Hirsch, T.; Nouri, B.; Pitz-Paal, R.

    2016-05-01

    A large number of commercial and research line focusing solar power plants are in operation and under development. Such plants include parabolic trough collectors (PTC) or linear Fresnel using thermal oil or molten salt as the heat transfer medium (HTM). However, the continuously varying and dynamic solar condition represent a big challenge for the plant control in order to optimize its power production and to keep the operation safe. A better understanding of the behaviour of such power plants under transient conditions will help reduce defocusing instances, improve field control, and hence, increase the energy yield and confidence in this new technology. Computational methods are very powerful and cost-effective tools to gain such understanding. However, most simulation models described in literature assume equal mass flow distributions among the parallel loops in the field or totally decouple the flow and thermal conditions. In this paper, a new numerical model to simulate a whole solar field with single-phase HTM is described. The proposed model consists of a hydraulic part and a thermal part that are coupled to account for the effect of the thermal condition of the field on the flow distribution among the parallel loops. The model is specifically designed for large line-focusing solar fields offering a high degree of flexibility in terms of layout, condition of the mirrors, and spatially resolved DNI data. Moreover, the model results have been compared to other simulation tools, as well as experimental and plant data, and the results show very good agreement. The model can provide more precise data to the control algorithms to improve the plant control. In addition, short-term and accurate spatially discretized DNI forecasts can be used as input to predict the field behaviour in-advance. In this paper, the hydraulic and thermal parts, as well as the coupling procedure, are described and some validation results and results of simulating an example field are

  8. Pregnancy prediction in single embryo transfer cycles after ICSI using QPCR: validation in oocytes from the same cohort.

    PubMed

    Wathlet, Sandra; Adriaenssens, Tom; Segers, Ingrid; Verheyen, Greta; Van Landuyt, Lisbet; Coucke, Wim; Devroey, Paul; Smitz, Johan

    2013-01-01

    Cumulus cell (CC) gene expression is being explored as an additional method to morphological scoring to choose the embryo with the highest chance to pregnancy. In 47 ICSI patients with single embryo transfer (SET), from which individual CC samples had been stored, 12 genes using QPCR were retrospectively analyzed. The CC samples were at the same occasion also used to validate a previously obtained pregnancy prediction model comprising three genes (ephrin-B2 (EFNB2), calcium/calmodulin-dependent protein kinase ID, stanniocalcin 1). Latter validation yielded a correct pregnant/non-pregnant classification in 72% of the samples. Subsequently, 9 new genes were analyzed on the same samples and new prediction models were built. Out of the 12 genes analyzed a combination of the best predictive genes was obtained by stepwise multiple regression. One model retained EFNB2 in combination with glutathione S-transferase alpha 3 and 4, progesterone receptor and glutathione peroxidase 3, resulting in 93% correct predictions when 3 patient and treatment cycle characteristics were included into the model. This large patient group allowed to do an intra-patient analysis for 7 patients, an analysis mimicking the methodology that would ultimately be used in clinical routine. CC related to a SET that did not give pregnancy and CC related to their subsequent frozen/thawed embryos which ended in pregnancy were analyzed. The models obtained in the between-patient analysis were used to rank the oocytes within-patients for their chance to pregnancy and resulted in 86% of correct predictions. In conclusion, prediction models built on selected quantified transcripts in CC might help in the decision making process which is currently only based on subjective embryo morphology scoring. The validity of our current models for routine application still need prospective assessment in a larger and more diverse patient population allowing intra-patient analysis.

  9. Polymerization Induced Self-Assembly of Alginate Based Amphiphilic Graft Copolymers Synthesized by Single Electron Transfer Living Radical Polymerization.

    PubMed

    Kapishon, Vitaliy; Whitney, Ralph A; Champagne, Pascale; Cunningham, Michael F; Neufeld, Ronald J

    2015-07-13

    Alginate-based amphiphilic graft copolymers were synthesized by single electron transfer living radical polymerization (SET-LRP), forming stable micelles during polymerization induced self-assembly (PISA). First, alginate macroinitiator was prepared by partial depolymerization of native alginate, solubility modification and attachment of initiator. Depolymerized low molecular weight alginate (∼12 000 g/mol) was modified with tetrabutylammonium, enabling miscibility in anhydrous organic solvents, followed by initiator attachment via esterification yielding a macroinitiator with a degree of substitution of 0.02, or 1-2 initiator groups per alginate chain. Then, methyl methacrylate was polymerized from the alginate macroinitiator in mixtures of water and methanol, forming poly(methyl methacrylate) grafts, prior to self-assembly, of ∼75 000 g/mol and polydispersity of 1.2. PISA of the amphiphilic graft-copolymer resulted in the formation of micelles with diameters of 50-300 nm characterized by light scattering and electron microscopy. As the first reported case of LRP from alginate, this work introduces a synthetic route to a preparation of alginate-based hybrid polymers with a precise macromolecular architecture and desired functionalities. The intended application is the preparation of micelles for drug delivery; however, LRP from alginate can also be applied in the field of biomaterials to the improvement of alginate-based hydrogel systems such as nano- and microhydrogel particles, islet encapsulation materials, hydrogel implants, and topical applications. Such modified alginates can also improve the function and application of native alginates in food and agricultural applications.

  10. Influence of heat and mass transfer on the ignition and NO x formation in single droplet combustion

    NASA Astrophysics Data System (ADS)

    Moesl, Klaus G.; Schwing, Joachim E.; Fenninger, Wolfgang J.; Sattelmayer, Thomas

    2011-08-01

    The effect of heat and mass transfer on the ignition, and in a second step on the nitrogen oxide (NO x ) generation, of single burning droplets is examined in a numerical study. Spherical symmetry with no gravity and no forced convection is presumed; ambient temperature is set at 500 K, below the auto-ignition point. The essentials of a forced droplet ignition by an external energy source are introduced. Two methods are applied: heat introduction at a fixed radial position r and heat introduction at a fixed local equivalence ratio ϕ r . This study's distinctiveness compared to previous research is its focus on and its combination of partially pre-vaporized droplets and detailed chemistry, both being technically relevant in kerosene and diesel fuel combustion. The fuel of choice is n-decane (C10H22), and NO x production is studied exemplarily as a representative group of pollutant emissions. The conducted simulations show a decrease of NO x formation with an increase of the pre-vaporization rate Uppsi. This decrease is generally valid for both methods of heat introduction. However, results on flame stabilization and NO x production reveal a high sensitivity to parameters of the ignition model. The burning behavior during the initial stages is dominated by the ignition position. Extracting heat from the exhaust gas region of burning droplets shows no impact on the flame position nor on the relative NO x production. As a consequence, a well-founded modeling of the investigated droplet regime needs to resort to an iterative adaptation of the heat introduction parameters based on the findings of droplet burning and exhaust gas production.

  11. Heat-transfer resistance at solid-liquid interfaces: a tool for the detection of single-nucleotide polymorphisms in DNA.

    PubMed

    van Grinsven, Bart; Vanden Bon, Natalie; Strauven, Hannelore; Grieten, Lars; Murib, Mohammed; Monroy, Kathia L Jiménez; Janssens, Stoffel D; Haenen, Ken; Schöning, Michael J; Vermeeren, Veronique; Ameloot, Marcel; Michiels, Luc; Thoelen, Ronald; De Ceuninck, Ward; Wagner, Patrick

    2012-03-27

    In this article, we report on the heat-transfer resistance at interfaces as a novel, denaturation-based method to detect single-nucleotide polymorphisms in DNA. We observed that a molecular brush of double-stranded DNA grafted onto synthetic diamond surfaces does not notably affect the heat-transfer resistance at the solid-to-liquid interface. In contrast to this, molecular brushes of single-stranded DNA cause, surprisingly, a substantially higher heat-transfer resistance and behave like a thermally insulating layer. This effect can be utilized to identify ds-DNA melting temperatures via the switching from low- to high heat-transfer resistance. The melting temperatures identified with this method for different DNA duplexes (29 base pairs without and with built-in mutations) correlate nicely with data calculated by modeling. The method is fast, label-free (without the need for fluorescent or radioactive markers), allows for repetitive measurements, and can also be extended toward array formats. Reference measurements by confocal fluorescence microscopy and impedance spectroscopy confirm that the switching of heat-transfer resistance upon denaturation is indeed related to the thermal on-chip denaturation of DNA.

  12. Nuclear transfer from sexed parent embryos in cattle: efficiency and birth of offspring.

    PubMed

    Le Bourhis, D; Chesne, P; Nibart, M; Marchal, J; Humblot, P; Renard, J P; Heyman, Y

    1998-07-01

    The objectives of this study were to evaluate the efficiency and reliability of embryo sexing from isolated single blastomeres, and after nuclear transfer to examine the influence of the sex of donor embryos on development in vitro and in vivo up to calving. The sex of the donor embryo was determined by revealing a specific Y DNA sequence by PCR and electrophoresis after isolation of one, two, three, or more than five cells. The efficiency of sex determination was over 90% and reliability was 100% independent of the number of blastomeres used. In a second experiment, sex was determined from a single cell and the other cells were used for nuclear transfer. The effect of sex on in vitro development was studied in 386 male and 314 female reconstructed embryos derived from 19 male and 14 female parent embryos, respectively. Developmental competence in vitro of male and female constructs over 7 days was not statistically different (25.2 and 23.1% blastocysts on day 7, respectively; P > 0.05). After the transfer of predetermined male (n = 30) and female (n = 27) cloned embryos into recipient heifers, no effect of sex was observed on pregnancy rates at day 21, 35 and 90, or on calving rates (P > 0.05). These rates did not differ between single and twin transfer (P > 0.05). The sex of the calves born always corresponded to that determined from a single blastomere. These results show that sex can be determined accurately when using a single blastomere before nuclear transfer and that the sex of the parent embryo does not affect in vitro development or in vivo survival rates of cloned embryos.

  13. Porcine Cloned Embryos Reconstructed with the Cell Nuclei of Tetraploid M-phase Fibroblast Cells Can Restore Normal Diploidy at the Blastocyst Stage.

    PubMed

    Zhao, Q; Qiu, Y G; Tian, J T; Wang, C S; An, T Z

    2016-11-17

    The cell cycle of donor cells as a major factor that affects cloning efficiency remains debatable. G2/M phase cells as a donor can successfully produce cloned animals, but a minimal amount is known regarding nuclear remodeling events. In this study, porcine fetal fibroblasts (PFFs) were carefully synchronized at G1 or M phase as donor cells. Most of the cloned embryos reconstructed from PFFs at G1 (G1-embryos) or M (M-embryos) phase formed a pronucleus-like nucleus (PN) within 6-h post fusion (hpf), but the M-embryos formed PN earlier than the G1-embryos did. Moreover, 77.4% of the M-embryos formed two PNs, whereas the G1-embryos formed a single PN. The rate of extrusion of polar body-like structures by the M-embryos was significantly lower than that extruded by the G1-embryos (26.3% vs. 37.1%, P < 0.05), and DNA synthesis in most embryos in both groups was initiated at 9-12 hpf. Most of the M-embryos were octoploid before the first cleavage. Furthermore, 81.25% of the blastomeres of blastocysts developed from the M-embryos showed abnormal ploidy compared with those developed from the G1-embryos (22.55%). However, some of the blastomeres remained diploid in all the M-embryos tested. A portion of the blastomeres restored normal diploidy in some of the M-embryos at the blastocyst stage. This finding provides an explanation for M-embryos developing to term.

  14. Accumulative charge separation for solar fuels production: coupling light-induced single electron transfer to multielectron catalysis.

    PubMed

    Hammarström, Leif

    2015-03-17

    The conversion and storage of solar energy into a fuel holds promise to provide a significant part of the future renewable energy demand of our societies. Solar energy technologies today generate heat or electricity, while the large majority of our energy is used in the form of fuels. Direct conversion of solar energy to a fuel would satisfy our needs for storable energy on a large scale. Solar fuels can be generated by absorbing light and converting its energy to chemical energy by electron transfer leading to separation of electrons and holes. The electrons are used in the catalytic reduction of a cheap substrate with low energy content into a high-energy fuel. The holes are filled by oxidation of water, which is the only electron source available for large scale solar fuel production. Absorption of a single photon typically leads to separation of a single electron-hole pair. In contrast, fuel production and water oxidation are multielectron, multiproton reactions. Therefore, a system for direct solar fuel production must be able to accumulate the electrons and holes provided by the sequential absorption of several photons in order to complete the catalytic reactions. In this Account, the process is termed accumulative charge separation. This is considerably more complicated than charge separation on a single electron level and needs particular attention. Semiconductor materials and molecular dyes have for a long time been optimized for use in photovoltaic devices. Efforts are made to develop new systems for light harvesting and charge separation that are better optimized for solar fuel production than those used in the early devices presented so far. Significant progress has recently been made in the discovery and design of better homogeneous and heterogeneous catalysts for solar fuels and water oxidation. While the heterogeneous ones perform better today, molecular catalysts based on transition metal complexes offer much greater tunability of electronic and

  15. Molecular cytogenetic analysis of human blastocysts andcytotrophoblasts by multi-color FISH and Spectra Imaging analyses

    SciTech Connect

    Weier, Jingly F.; Ferlatte, Christy; Baumgartner, Adolf; Jung,Christine J.; Nguyen, Ha-Nam; Chu, Lisa W.; Pedersen, Roger A.; Fisher,Susan J.; Weier, Heinz-Ulrich G.

    2006-02-08

    Numerical chromosome aberrations in gametes typically lead to failed fertilization, spontaneous abortion or a chromosomally abnormal fetus. By means of preimplantation genetic diagnosis (PGD), we now can screen human embryos in vitro for aneuploidy before transferring the embryos to the uterus. PGD allows us to select unaffected embryos for transfer and increases the implantation rate in in vitro fertilization programs. Molecular cytogenetic analyses using multi-color fluorescence in situ hybridization (FISH) of blastomeres have become the major tool for preimplantation genetic screening of aneuploidy. However, current FISH technology can test for only a small number of chromosome abnormalities and hitherto failed to increase the pregnancy rates as expected. We are in the process of developing technologies to score all 24 chromosomes in single cells within a 3 day time limit, which we believe is vital to the clinical setting. Also, human placental cytotrophoblasts (CTBs) at the fetal-maternal interface acquire aneuploidies as they differentiate to an invasive phenotype. About 20-50% of invasive CTB cells from uncomplicated pregnancies were found aneuploidy, suggesting that the acquisition of aneuploidy is an important component of normal placentation, perhaps limiting the proliferative and invasive potential of CTBs. Since most invasive CTBs are interphase cells and possess extreme heterogeneity, we applied multi-color FISH and repeated hybridizations to investigate individual CTBs. In summary, this study demonstrates the strength of Spectral Imaging analysis and repeated hybridizations, which provides a basis for full karyotype analysis of single interphase cells.

  16. Determination of blade-to-coolant heat-transfer coefficients on a forced-convection, water-cooled, single-stage turbine

    NASA Technical Reports Server (NTRS)

    Freche, John C; Schum, Eugene F

    1951-01-01

    Blade-to-coolant convective heat-transfer coefficients were obtained on a forced-convection water-cooled single-stage turbine over a large laminar flow range and over a portion of the transition range between laminar and turbulent flow. The convective coefficients were correlated by the general relation for forced-convection heat transfer with laminar flow. Natural-convection heat transfer was negligible for this turbine over the Grashof number range investigated. Comparison of turbine data with stationary tube data for the laminar flow of heated liquids showed good agreement. Calculated average midspan blade temperatures using theoretical gas-to-blade coefficients and blade-to-coolant coefficients from stationary-tube data resulted in close agreement with experimental data.

  17. Derivation of Porcine Embryonic Stem-Like Cells from In Vitro-Produced Blastocyst-Stage Embryos

    PubMed Central

    Hou, Dao-Rong; Jin, Yong; Nie, Xiao-Wei; Zhang, Man-Ling; Ta, Na; Zhao, Li-Hua; Yang, Ning; Chen, Yuan; Wu, Zhao-Qiang; Jiang, Hai-Bin; Li, Yan-Ru; Sun, Qing-Yuan; Dai, Yi-Fan; Li, Rong-Feng

    2016-01-01

    Efficient isolation of embryonic stem (ES) cells from pre-implantation porcine embryos has remained a challenge. Here, we describe the derivation of porcine embryonic stem-like cells (pESLCs) by seeding the isolated inner cell mass (ICM) from in vitro-produced porcine blastocyst into α-MEM with basic fibroblast growth factor (bFGF). The pESL cells kept the normal karyotype and displayed flatten clones, similar in phenotype to human embryonic stem cells (hES cells) and rodent epiblast stem cells. These cells exhibited alkaline phosphatase (AP) activity and expressed pluripotency markers such as OCT4, NANOG, SOX2, SSEA-4, TRA-1-60, and TRA-1-81 as determined by both immunofluorescence and RT-PCR. Additionally, these cells formed embryoid body (EB), teratomas and also differentiated into 3 germ layers in vitro and in vivo. Microarray analysis showed the expression of the pluripotency markers, PODXL, REX1, SOX2, KLF5 and NR6A1, was significantly higher compared with porcine embryonic fibroblasts (PEF), but expression of OCT4, TBX3, REX1, LIN28A and DPPA5, was lower compared to the whole blastocysts or ICM of blastocyst. Our results showed that porcine embryonic stem-like cells can be established from in vitro-produced blastocyst-stage embryos, which promote porcine naive ES cells to be established. PMID:27173828

  18. Derivation of embryonic stem cells from Kunming mice IVF blastocyst in feeder- and serum-free condition.

    PubMed

    Liu, Xiaokun; Wei, Qiang; Zhang, Junhong; Yang, Wanli; Zhao, Xiaoe; Ma, Baohua

    2015-06-01

    Kunming mice are widely used in China; however, it is difficult to isolate embryonic stem cells (ESCs) in conventional derivation condition containing feeder cells and serum. 6-Bromoindirubin-3'-oxime (BIO), a glycogen synthase kinase 3 (GSK3) inhibitor, could facilitate the maintenance of pluripotency of ESCs. Therefore, BIO could be considered as a candidate to replace feeder cells and serum. On the other hand, in vitro fertilization (IVF) is an important technology in assisted reproduction. It is reported that there was some difference in gene expression between IVF and in vivo developed blastocyst. ESCs derived from IVF blastocyst could provide a valuable tool to research the effect of IVF on differentiation and development. In the present study, we established two novel ESC lines from IVF blastocyst of Kunming mice in a feeder- and serum-free condition containing 2.5 μM BIO. In this condition, expanded IVF blastocyst could spontaneously hatch from zonae pellucidae and attached to the gelatin-coated bottom of dishes. ESC-like outgrowth could be observed without overfull trophoblast cells. After further propagation, two Kunming mice ESC lines, designated as KMES1 and KMES2, were obtained. These two novel ESCs shared common morphological characteristics with other rodent ESCs, showed strong alkaline phosphatase activity, and expressed pluripotent markers, including Oct-4, Nanog, and SSEA-1. Embryoid body (EB) and teratoma test indicated that these ESCs could spontaneously differentiate into cells representative of all three embryonic germ layers.

  19. Contribution of oocyte source and culture conditions to phenotypic and transcriptomic variation in commercially produced bovine blastocysts.

    PubMed

    Plourde, Dany; Vigneault, Christian; Lemay, Alexandra; Breton, Lévéke; Gagné, Dominic; Laflamme, Isabelle; Blondin, Patrick; Robert, Claude

    2012-07-01

    Bovine embryo production is practiced worldwide for commercial purposes. A major concern of embryo suppliers is the impact of in vitro production systems on embryo quality. In the present study, we compared Buffalo Rat Liver cell coculture with semidefined, medium-based culture, oocytes recovered postmortem with those obtained from live animals, and in vitro with in vivo embryo development. Gene expression levels in expanded blastocysts were measured using microarray and quantitative RT-PCR. The systems were similar in terms of blastocyst yield and rate of development, whereas embryo productivity was greater for immature oocytes collected in vivo. Although immature oocytes collected in vivo had greater developmental competence, they yielded blastocysts that were indistinguishable (in terms of level of gene expression) from embryos derived from immature oocytes recovered postmortem. Culture conditions had a significant impact on gene expression, particularly among genes involved in lipid metabolism. Numerous uncharacterized novel transcript regions were also influenced by in vitro treatments. In conclusion, ovum pick-up combined with in vitro culture in semidefined medium provided a high blastocyst yield, without the deleterious effects associated with coculture.

  20. Meaning and Measurability of Single-Ion Activities, the Thermodynamic Foundations of pH, and the Gibbs Free Energy for the Transfer of Ions between Dissimilar Materials

    PubMed Central

    Rockwood, Alan L

    2015-01-01

    Considering the relationship between concentration and vapor pressure (or the relationship between concentration and fugacity) single-ion activity coefficients are definable in purely thermodynamic terms. The measurement process involves measuring a contact potential between a solution and an external electrode. Contact potentials are measurable by using thermodynamically reversible processes. Extrapolation of an equation to zero concentration and ionic strength enables determination of single-ion activity coefficients. Single-ion activities can be defined and measured without using any extra-thermodynamic assumptions, concepts, or measurements. This method could serve as a gold standard for the validation of extra-thermodynamic methods for determining single-ion activities. Furthermore, it places the concept of pH on a thermodynamically solid foundation. Contact potential measurements can also be used to determine the Gibbs free energy for the transfer of ions between dissimilar materials. PMID:25919971

  1. TallyHO obese female mice experience poor reproductive outcomes and abnormal blastocyst metabolism which is reversed by metformin

    PubMed Central

    Louden, Erica D.; Luzzo, Kerri M.; Jimenez, Patricia T.; Chi, Tiffany; Chi, Maggie; Moley, Kelle H.

    2015-01-01

    Objective Obese women experience worse reproductive outcomes compared to normal weight women, specifically infertility, pregnancy loss, fetal malformations and developmental delay. The objective of this study was to use a genetic mouse model of obesity in order to recapitulate the human reproductive phenotype and further examine potential mechanisms and therapies. Methods New inbred, polygenic Type 2 diabetic TallyHO mice and age matched control C57BL/6 mice were superovulated to obtain morulae or blastocysts stage embryos which were cultured in human tubal fluid media. Deoxyglucose uptake was performed on insulin-stimulated individual blastocysts. Apoptosis was detected by confocal microscopy using TUNEL assay and Topro-3 nuclear dye. Embryos were scored for %TUNEL positive/total nuclei. AMPK activation, TNFα expression, and adiponectin expression were analyzed by western immunoblot and confocal immunofluorescent microscopy. Lipid accumulation was assayed by Bodipy. Finally all measured parameters were compared between TallyHO mice in morulaes cultured to blastocyst embryos in either human tubal fluid (HTF) media or HTF with 25ug/ml metformin added. Results TallyHo mice developed whole body abnormal insulin tolerance, decreased litter number and increased NEFA. Blastocysts demonstrated increased apoptosis, decreased insulin sensitivity, and decreased activation of AMP activated protein-kinase (AMPK). As a possible cause of the insulin resistance/abnormal P-AMPK, we found that Tumor necrosis Factor (TNFα) expression and lipid accumulation as detected by BODIPY were increased in TallyHO blastocysts and adiponectin was decreased. Culturing TallyHO morulae with the AMPK activator, metformin lead to a reversal of all abnormal findings, including increased p-AMPK, improved insulin-stimulated glucose uptake and normalization of lipid accumulation. Conclusions Women with obesity and insulin resistance experience poor pregnancy outcomes. Previously we have shown in mouse

  2. Biodynamic imaging of live porcine oocytes, zygotes and blastocysts for viability assessment in assisted reproductive technologies

    PubMed Central

    An, Ran; Wang, Chunmin; Turek, John; Machaty, Zoltan; Nolte, David D.

    2015-01-01

    The success of assisted reproductive technologies relies on accurate assessment of reproductive viability at successive stages of development for oocytes and embryos. The current scoring system used to select good-quality oocytes relies on morphologically observable traits and hence is indirect and subjective. Biodynamic imaging may provide an objective approach to oocyte and embryo assessment by measuring physiologically-relevant dynamics. Biodynamic imaging is a coherence-gated approach to 3D tissue imaging that uses digital holography to perform low-coherence speckle interferometry to capture dynamic light scattering from intracellular motions. The changes in intracellular activity during cumulus oocyte complex maturation, before and after in vitro fertilization, and the subsequent development of the zygote and blastocyst provide a new approach to the assessment of preimplant candidates. PMID:25798318

  3. Interplay of hole transfer and host-guest interaction in a molecular dyad and triad: ensemble and single-molecule spectroscopy and sensing applications.

    PubMed

    Wu, Xiangyang; Liu, Fang; Wells, Kym L; Tan, Serena L J; Webster, Richard D; Tan, Howe-Siang; Zhang, Dawei; Xing, Bengang; Yeow, Edwin K L

    2015-02-16

    A new molecular dyad consisting of a Cy5 chromophore and ferrocene (Fc) and a triad consisting of Cy5, Fc, and β-cyclodextrin (CD) are synthesized and their photophysical properties investigated at both the ensemble and single-molecule levels. Hole transfer efficiency from Cy5 to Fc in the dyad is reduced upon addition of CD. This is due to an increase in the Cy5-Fc separation (r) when the Fc is encapsulated in the macrocyclic host. On the other hand, the triad adopts either a Fc-CD inclusion complex conformation in which hole transfer quenching of the Cy5 by Fc is minimal or a quasi-static conformation with short r and rapid charge transfer. Single-molecule fluorescence measurements reveal that r is lengthened when the triad molecules are deposited on a glass substrate. By combining intramolecular charge transfer and competitive supramolecular interaction, the triad acts as an efficient chemical sensor to detect different bioactive analytes such as amantadine hydrochloride and sodium lithocholate in aqueous solution and synthetic urine.

  4. Single-stage Reconstruction of Elbow Flexion Associated with Massive Soft-Tissue Defect Using the Latissimus Dorsi Muscle Bipolar Rotational Transfer.

    PubMed

    Stevanovic, Milan V; Cuéllar, Vanessa G; Ghiassi, Alidad; Sharpe, Frances

    2016-09-01

    In the upper extremity, the latissimus dorsi muscle can be used as an ipsilateral rotational muscle flap for soft-tissue coverage or functional reconstruction of arm and elbow. Patients who have both major soft-tissue loss and functional deficits can be successfully treated with a single-stage functional latissimus dorsi rotational muscle transfer that provides simultaneous soft-tissue coverage and functional reconstruction.

  5. Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F4TCNQ.

    PubMed

    García, Raúl; Herranz, M Ángeles; Leary, Edmund; González, M Teresa; Bollinger, Gabino Rubio; Bürkle, Marius; Zotti, Linda A; Asai, Yoshihiro; Pauly, Fabian; Cuevas, Juan Carlos; Agraït, Nicolás; Martín, Nazario

    2015-01-01

    We describe the synthesis and single-molecule electrical transport properties of a molecular wire containing a π-extended tetrathiafulvalene (exTTF) group and its charge-transfer complex with F4TCNQ. We form single-molecule junctions using the in situ break junction technique using a homebuilt scanning tunneling microscope with a range of conductance between 10 G0 down to 10(-7) G0. Within this range we do not observe a clear conductance signature of the neutral parent molecule, suggesting either that its conductance is too low or that it does not form a stable junction. Conversely, we do find a clear conductance signature in the experiments carried out on the charge-transfer complex. Due to the fact we expected this species to have a higher conductance than the neutral molecule, we believe this supports the idea that the conductance of the neutral molecule is very low, below our measurement sensitivity. This idea is further supported by theoretical calculations. To the best of our knowledge, these are the first reported single-molecule conductance measurements on a molecular charge-transfer species.

  6. Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F4TCNQ

    PubMed Central

    García, Raúl; Herranz, M Ángeles; González, M Teresa; Bollinger, Gabino Rubio; Bürkle, Marius; Zotti, Linda A; Asai, Yoshihiro; Pauly, Fabian; Cuevas, Juan Carlos; Agraït, Nicolás

    2015-01-01

    Summary We describe the synthesis and single-molecule electrical transport properties of a molecular wire containing a π-extended tetrathiafulvalene (exTTF) group and its charge-transfer complex with F4TCNQ. We form single-molecule junctions using the in situ break junction technique using a homebuilt scanning tunneling microscope with a range of conductance between 10 G0 down to 10−7 G0. Within this range we do not observe a clear conductance signature of the neutral parent molecule, suggesting either that its conductance is too low or that it does not form a stable junction. Conversely, we do find a clear conductance signature in the experiments carried out on the charge-transfer complex. Due to the fact we expected this species to have a higher conductance than the neutral molecule, we believe this supports the idea that the conductance of the neutral molecule is very low, below our measurement sensitivity. This idea is further supported by theoretical calculations. To the best of our knowledge, these are the first reported single-molecule conductance measurements on a molecular charge-transfer species. PMID:26199662

  7. Microchip electrophoresis-single wall carbon nanotube press-transferred electrodes for fast and reliable electrochemical sensing of melatonin and its precursors.

    PubMed

    Gomez, Federico José Vicente; Martín, Aída; Silva, María Fernanda; Escarpa, Alberto

    2015-08-01

    In the current work, single-wall carbon nanotube press-transferred electrodes (SW-PTEs) were used for detection of melatonin (MT) and its precursors tryptophan (Trp) and serotonin (5-HT) on microchip electrophoresis (ME). SW-PTEs were simply fabricated by press transferring a filtered dispersion of single-wall carbon nanotubes on a nonconductive PMMA substrate, where single-wall carbon nanotubes act as exclusive transducers. The coupling of ME-SW-PTEs allowed the fast detection of MT, Trp, and 5-HT in less than 150 s with excellent analytical features. It exhibited an impressive antifouling performance with RSD values of ≤2 and ≤4% for migration times and peak heights, respectively (n = 12). In addition, sample analysis was also investigated by analysis of 5-HT, MT, and Trp in commercial samples obtaining excellent quantitative and reproducible recoveries with values of 96.2 ± 1.8%, 101.3 ± 0.2%, and 95.6 ± 1.2% for 5-HT, MT, and Trp, respectively. The current novel application reveals the analytical power of the press-transfer technology where the fast and reliable determination of MT and its precursors were performed directly on the nanoscale carbon nanotube detectors without the help of any other electrochemical transducer.

  8. Cryopreservation method affects DNA fragmentation in trophectoderm and the speed of re-expansion in bovine blastocysts.

    PubMed

    Inaba, Yasushi; Miyashita, Satoshi; Somfai, Tamás; Geshi, Masaya; Matoba, Satoko; Dochi, Osamu; Nagai, Takashi

    2016-04-01

    This study investigated re-expansion dynamics during culture of bovine blastocysts cryopreserved either by slow-freezing or vitrification. Also, the extent and localization of membrane damage and DNA fragmentation in re-expanded embryos were studied. Frozen-thawed embryos showed a significantly lower re-expansion rate during 24 h of post-thawing culture compared to vitrified embryos. Vitrified embryos reached the maximum level of re-expansion rate by 12 h of culture whereas frozen embryos showed a gradual increase in re-expansion rate by 24 h of culture. When assayed by Hoechst/propidium iodide staining there was no difference in the numbers and ratio of membrane damaged cells between re-expanded frozen and vitrified embryos; however, the extent of membrane damage in blastomeres was significantly higher in both groups compared with non-cryopreserved embryos (control). TUNEL assay combined with differential ICM and TE staining revealed a significantly higher number and ratio of TE cells showing DNA-fragmentation in frozen-thawed re-expanded blastocysts compared to vitrified ones; however, vitrification also resulted in an increased extent of DNA fragmentation in TE cells compared with control blastocysts. In frozen-thawed blastocysts increased extent of DNA fragmentation was associated with reduced numbers and proportion of TE cells compared with vitrified and control embryos. The number and ratio of ICM cells and the extent of DNA fragmentation in ICM did not differ among control, frozen and vitrified groups. In conclusion, compared with vitrified embryos, blastocysts preserved by slow-freezing showed a delayed timing of re-expansion which was associated with an increased frequency of DNA fragmentation in TE cells.

  9. Development of a surface array of microscale heaters to measure wall heat transfer underneath single bubbles in nucleate pool boiling

    SciTech Connect

    Kim, J.; Kalkur, T.S.

    1995-12-31

    A novel array of microscale heaters has been developed to measure the heat transfer coefficient at many points underneath individual bubbles during boiling as a function of space and time. This heater array enables the local heat transfer from a surface during the bubble growth and departure process to be measured with very high temporal and spatial resolution, and should allow better understanding of the boiling heat transfer mechanisms by pinpointing when and where in the bubble departure cycle large amounts of wall heat transfer occur. Such information can provide much needed data regarding the important heat transfer mechanisms during the bubble departure cycle, and can serve as benchmarks to validate many of the analytical and numerical models used to simulate boiling. The current array has 148 heaters within a 3 mm diameter circle. Feedback loops similar to those used in hot-wire anemometry are used to keep each heater at a constant temperature, and the power required to do this is directly related to the heat transfer coefficient. A description of the heater performance and construction, the feedback loops, the computer control circuit, and the calibration rig are described.

  10. Birth of Cloned Microminipigs Derived from Somatic Cell Nuclear Transfer Embryos That Have Been Transiently Treated with Valproic Acid.

    PubMed

    Miyoshi, Kazuchika; Kawaguchi, Hiroaki; Maeda, Kosuke; Sato, Masahiro; Akioka, Kohei; Noguchi, Michiko; Horiuchi, Masahisa; Tanimoto, Akihide

    2016-11-01

    In our previous study, we found that treatment of miniature pig somatic cell nuclear transfer (SCNT) embryos with 4 mM valproic acid (VPA), a histone deacetylase inhibitor, for 48 hours after activation enhanced blastocyst formation rate and octamer-binding transcription factor-3/4 (Oct-3/4) gene expression at the late blastocyst stage; however, the production of viable cloned pups failed, when those VPA-treated SCNT embryos were transferred to recipients. This failure suggests that the present VPA treatment is suboptimal. In the present study, we explored the optimal conditions for VPA to have beneficial effects on the development of SCNT embryos. When miniature pig SCNT embryos were treated with 8 mM VPA for 24 hours after activation, both the rates of blastocyst formation and blastocysts expressing the Oct-3/4 gene were significantly (p < 0.05) improved. A similar increase in blastocyst formation was also observed when microminipig-derived cells were used as SCNT donors. Five cloned piglets were obtained after the transfer of 152 microminipig SCNT embryos that had been treated with 8 mM VPA for 24 hours. The results indicated that a short duration of treatment with VPA improves the development of both miniature pig and microminipig SCNT embryos, possibly via an enhanced reprogramming mechanism.

  11. Defined media optimization for in vitro culture of bovine somatic cell nuclear transfer (SCNT) embryos.

    PubMed

    Wang, Li-Jun; Xiong, Xian-Rong; Zhang, Hui; Li, Yan-Yan; Li, Qian; Wang, Yong-Sheng; Xu, Wen-Bing; Hua, Song; Zhang, Yong

    2012-12-01

    The objective was to establish an efficient defined culture medium for bovine somatic cell nuclear transfer (SCNT) embryos. In this study, modified synthetic oviductal fluid (mSOF) without bovine serum albumin (BSA) was used as the basic culture medium (BCM), whereas the control medium was BCM with BSA. In Experiment 1, adding polyvinyl alcohol (PVA) to BCM supported development of SCNT embryos to blastocyst stage, but blastocyst formation rate and blastocyst cell number were both lower (P < 0.05) compared to the undefined group (6.1 vs. 32.6% and 67.3 ± 3.4 vs. 109.3 ± 4.5, respectively). In Experiment 2, myo-inositol, a combination of insulin, transferrin and selenium (ITS), and epidermal growth factor (EGF) were added separately to PVA-supplemented BCM. The blastocyst formation rate and blastocyst cell number of those three groups were dramatically improved compared with that of PVA-supplemented group in Experiment 1 (18.5, 23.0, 24.1 vs. 6.1% and 82.7 ± 2.0, 84.3 ± 4.2, 95.3 ± 3.8 vs. 67.3 ± 3.4, respectively, P < 0.05), but were still lower compared with that of undefined group (33.7% and 113.8 ± 3.4, P < 0.05). In Experiment 3, when a combination of myo-inositol, ITS and EGF were added to PVA-supplemented BCM, blastocyst formation rate and blastocyst cell number were similar to that of undefined group (30.4 vs. 31.1% and 109.3 ± 4.4 vs. 112.0 ± 3.6, P > 0.05). In Experiment 4, when blastocysts were cryopreserved and subsequently thawed, there were no significant differences between the optimized defined group (Experiment 3) and undefined group in survival rate and 24 and 48 h hatching blastocyst rates. Furthermore, there were no significant differences in expression levels of H19, HSP70 and BAX in blastocysts derived from optimized defined medium and undefined medium, although the relative expression abundance of IGF-2 was significantly decreased in the former. In conclusion, a defined culture medium containing PVA, myo-inositol, ITS, and EGF

  12. Optically enhanced charge transfer between C60 and single-wall carbon nanotubes in hybrid electronic devices

    NASA Astrophysics Data System (ADS)

    Allen, Christopher S.; Liu, Guoquan; Chen, Yabin; Robertson, Alex W.; He, Kuang; Porfyrakis, Kyriakos; Zhang, Jin; Briggs, G. Andrew D.; Warner, Jamie H.

    2013-12-01

    In this article we probe the nature of electronic interactions between the components of hybrid C60-carbon nanotube structures. Utilizing an aromatic mediator we selectively attach C60 molecules to carbon nanotube field-effect transistor devices. Structural characterization via atomic force and transmission electron microscopy confirm the selectivity of this attachment. Charge transfer from the carbon nanotube to the C60 molecules is evidenced by a blue shift of the Raman G+ peak position and increased threshold voltage of the transistor transfer characteristics. We estimate this charge transfer to increase the device density of holes per unit length by up to 0.85 nm-1 and demonstrate further optically enhanced charge transfer which increases the hole density by an additional 0.16 nm-1.In this article we probe the nature of electronic interactions between the components of hybrid C60-carbon nanotube structures. Utilizing an aromatic mediator we selectively attach C60 molecules to carbon nanotube field-effect transistor devices. Structural characterization via atomic force and transmission electron microscopy confirm the selectivity of this attachment. Charge transfer from the carbon nanotube to the C60 molecules is evidenced by a blue shift of the Raman G+ peak position and increased threshold voltage of the transistor transfer characteristics. We estimate this charge transfer to increase the device density of holes per unit length by up to 0.85 nm-1 and demonstrate further optically enhanced charge transfer which increases the hole density by an additional 0.16 nm-1. Electronic supplementary information (ESI) available: AFM line scans of the substrate before and after functionalization; scheme for measuring amorphous carbon coverage from TEM images; diameter comparisons of ac-TEM image and simulation of C60 molecule; Raman spectra D peak comparison; optical response of transfer properties of pristine devices; comparison between swept and pulsed Vg measurements

  13. Two culture systems showing a biphasic effect on ovine embryo development from the 1-2 cell stage to hatched blastocysts.

    PubMed

    Ledda, S; Bogliolo, L; Leoni, G; Loi, P; Cappai, P; Naitana, S

    1995-01-01

    This study compared the effect of using either CZB or TCM 199 media on both the development of 1-2 cell ovine embryos from superovulated ewes to the blastocyst stage (Experiment 1), and the hatching process of ovine blastocysts developed in vitro (Experiment 2). For the first 5 d, the CZB medium showed higher rates of embryo development than the TCM 199 medium (p < 0.001). The embryos reaching the > 16 cell stage were 79 vs 52% and 74 vs 20% with or without an oviductal monolayer, respectively, and those reaching the blastocyst stage were 71 vs 46% and 46 vs 13% with or without cells. The CZB medium was less able to support the hatching process of the blastocysts obtained in the first experiment than was the TCM-199 medium + 10% FCS (fetal calf serum) with cells (31 vs 92%; p < 0.001) or without cells (13 vs 66%; p < 0.001). No blastocysts completely escaped from the zona pellucida (ZP) in the CZB medium compared with 80 and 61% in the TCM 199 medium with or without cells, respectively. In Experiment 3, 47% of the blastocysts migrated through the artificial opening of the ZP and hatched completely. After 24 h of culture in the CZB medium, however, they showed blastocoelic cavity breakdown. During the preliminary cleavages, the ovine embryos developed better in CZB medium than in TCM 199, but the latter was more efficient in promoting the hatching process of the blastocysts.

  14. Adoptive transfer of Mammaglobin-A epitope specific CD8 T cells combined with a single low dose of total body irradiation eradicates breast tumors.

    PubMed

    Lerret, Nadine M; Rogozinska, Magdalena; Jaramillo, Andrés; Marzo, Amanda L

    2012-01-01

    Adoptive T cell therapy has proven to be beneficial in a number of tumor systems by targeting the relevant tumor antigen. The tumor antigen targeted in our model is Mammaglobin-A, expressed by approximately 80% of human breast tumors. Here we evaluated the use of adoptively transferred Mammaglobin-A specific CD8 T cells in combination with low dose irradiation to induce breast tumor rejection and prevent relapse. We show Mammaglobin-A specific CD8 T cells generated by DNA vaccination with all epitopes (Mammaglobin-A2.1, A2.2, A2.4 and A2.6) and full-length DNA in vivo resulted in heterogeneous T cell populations consisting of both effector and central memory CD8 T cell subsets. Adoptive transfer of spleen cells from all Mammaglobin-A2 immunized mice into tumor-bearing SCID/beige mice induced tumor regression but this anti-tumor response was not sustained long-term. Additionally, we demonstrate that only the adoptive transfer of Mammaglobin-A2 specific CD8 T cells in combination with a single low dose of irradiation prevents tumors from recurring. More importantly we show that this single dose of irradiation results in the down regulation of the macrophage scavenger receptor 1 on dendritic cells within the tumor and reduces lipid uptake by tumor resident dendritic cells potentially enabling the dendritic cells to present tumor antigen more efficiently and aid in tumor clearance. These data reveal the potential for adoptive transfer combined with a single low dose of total body irradiation as a suitable therapy for the treatment of established breast tumors and the prevention of tumor recurrence.

  15. Note: electronic circuit for two-way time transfer via a single coaxial cable with picosecond accuracy and precision.

    PubMed

    Prochazka, Ivan; Kodet, Jan; Panek, Petr

    2012-11-01

    We have designed, constructed, and tested the overall performance of the electronic circuit for the two-way time transfer between two timing devices over modest distances with sub-picosecond precision and a systematic error of a few picoseconds. The concept of the electronic circuit enables to carry out time tagging of pulses of interest in parallel to the comparison of the time scales of these timing devices. The key timing parameters of the circuit are: temperature change of the delay is below 100 fs/K, timing stability time deviation better than 8 fs for averaging time from minutes to hours, sub-picosecond time transfer precision, and a few picoseconds time transfer accuracy.

  16. Blinking fluorescence of single donor-acceptor pairs: important role of "dark'' states in resonance energy transfer via singlet levels.

    PubMed

    Osad'ko, I S; Shchukina, A L

    2012-06-01

    The influence of triplet levels on Förster resonance energy transfer via singlet levels in donor-acceptor (D-A) pairs is studied. Four types of D-A pair are considered: (i) two-level donor and two-level acceptor, (ii) three-level donor and two-level acceptor, (iii) two-level donor and three-level acceptor, and (iv) three-level donor and three-level acceptor. If singlet-triplet transitions in a three-level acceptor molecule are ineffective, the energy transfer efficiency E=I_{A}/(I_{A}+I_{D}), where I_{D} and I_{A} are the average intensities of donor and acceptor fluorescence, can be described by the simple theoretical equation E(F)=FT_{D}/(1+FT_{D}). Here F is the rate of energy transfer, and T_{D} is the donor fluorescence lifetime. In accordance with the last equation, 100% of the donor electronic energy can be transferred to an acceptor molecule at FT_{D}≫1. However, if singlet-triplet transitions in a three-level acceptor molecule are effective, the energy transfer efficiency is described by another theoretical equation, E(F)=F[over ¯](F)T_{D}/[1+F[over ¯](F)T_{D}]. Here F[over ¯](F) is a function of F depending on singlet-triplet transitions in both donor and acceptor molecules. Expressions for the functions F[over ¯](F) are derived. In this case the energy transfer efficiency will be far from 100% even at FT_{D}≫1. The character of the intensity fluctuations of donor and acceptor fluorescence indicates which of the two equations for E(F) should be used to find the value of the rate F. Therefore, random time instants of photon emission in both donor and acceptor fluorescence are calculated by the Monte Carlo method for all four types of D-A pair. Theoretical expressions for start-stop correlators (waiting time distributions) in donor and acceptor fluorescence are derived. The probabilities w_{N}^{D}(t) and w_{N}^{A}(t) of finding N photons of donor and acceptor fluorescence in the time interval t are calculated for various values of the energy

  17. Quantitative Connection between Ensemble Thermodynamics and Single-Molecule Kinetics: A Case Study Using Cryogenic Electron Microscopy and Single-Molecule Fluorescence Resonance Energy Transfer Investigations of the Ribosome.

    PubMed

    Kinz-Thompson, Colin D; Sharma, Ajeet K; Frank, Joachim; Gonzalez, Ruben L; Chowdhury, Debashish

    2015-08-27

    At equilibrium, thermodynamic and kinetic information can be extracted from biomolecular energy landscapes by many techniques. However, while static, ensemble techniques yield thermodynamic data, often only dynamic, single-molecule techniques can yield the kinetic data that describe transition-state energy barriers. Here we present a generalized framework based upon dwell-time distributions that can be used to connect such static, ensemble techniques with dynamic, single-molecule techniques, and thus characterize energy landscapes to greater resolutions. We demonstrate the utility of this framework by applying it to cryogenic electron microscopy (cryo-EM) and single-molecule fluorescence resonance energy transfer (smFRET) studies of the bacterial ribosomal pre-translocation complex. Among other benefits, application of this framework to these data explains why two transient, intermediate conformations of the pre-translocation complex, which are observed in a cryo-EM study, may not be observed in several smFRET studies.

  18. Production of piglets from in vitro-produced embryos following non-surgical transfer.

    PubMed

    Yoshioka, Koji; Noguchi, Michiko; Suzuki, Chie

    2012-03-01

    The objective of this study was to enhance procedures for producing piglets derived from in vitro-produced (IVP) pig embryos by non-surgical embryo transfer (ET). The effects of insertion length for the catheter, asynchrony between the age of donor IVP blastocysts and the recipient estrous cycle, and volume of transfer medium were investigated. The IVP blastocysts at 5 days after in vitro fertilization were placed into porcine zygote medium (PZM)-5 supplemented with 10% (v/v) fetal bovine serum (PZM+FBS) in a 0.25 mL plastic straw (21-40 blastocysts per straw) and then transferred into one uterine horn of recipients using the Takumi(®) catheter for deep intrauterine insertion. Successful production of piglets derived from IVP embryos was achieved following non-surgical ET when the catheter was inserted at more than 30 cm anterior to the spiral guide spirette. The efficiency of piglet production (percentage number of piglet(s) born based on the number of embryos transferred) was greater (P<0.05) in recipients whose estrous cycle was asynchronous to that of donors with a 1-day delay (8.3%) than in those with a 2-day (1.5%) or 3-day (0.9%) delay, while pregnancy and farrowing rates (10-40%) did not differ among treatments. When blastocysts were transferred into recipients with 1.0 or 2.5 mL PZM+FBS, there were no significant differences in farrowing rate (30-40%) or average litter size (4.5-6.7) between treatments. The results of the present study indicate that the insertion length of the deep intrauterine catheter and the degree of asynchrony between donor embryos and recipient estrous cycle influenced on pregnancy and birth outcome following non-surgical transfer of IVP blastocysts.

  19. Impact of the mandatory age-based single-embryo transfer legislation in Turkey on outcome of in vitro fertilization: a multicentre study.

    PubMed

    Ergun, B; Bastu, E; Galandarov, R; Koksal, G; Yumru, H; Attar, E

    2013-08-01

    This study in Turkey evaluated the impact of age-based mandatory single-embryo transfer (SET) legislation with the subsequent increase in frozen-thawed embryo transfer (FT-EU) on pregnancy outcome of in vitro fertilization (IVF) patients. SET, FT-FT and double-embryo transfer were used in 5632 patients after legislation, while traditional IVF and FT-FT approach was used in 6029 patients before legislation. The cumulative pregnancy rate after legislation was slightly lower (38.2%) than before legislation (42.0%) but not significantly so. The single pregnancy rate for SET and traditional IVF were similar between the 2 groups (37.8% versus 28.7%), while multiple pregnancy rates were significantly higher before than after legislation (13.7% versus 0.3%). For FT-ET, the number of cycles was significantly higher after legislation (862 versus 616). SET yielded similar results to traditional IVF. In order to reduce multiple pregnancies without significantly decreasing pregnancy rates, SET might be a successful strategy.

  20. Daily supplementation with ghrelin improves in vitro bovine blastocysts formation rate and alters gene expression related to embryo quality.

    PubMed

    Dovolou, Eleni; Periquesta, Eva; Messinis, Ioannis E; Tsiligianni, Theodora; Dafopoulos, Konstantinos; Gutierrez-Adan, Alfonso; Amiridis, Georgios S

    2014-03-01

    Ghrelin is a gastric peptide having regulatory role in the reproductive system functionality, acting mainly at central level. Because the expression of ghrelin system (ghrelin and its receptor) has been detected in the bovine ovary, the objectives of the present study were to investigate whether ghrelin can affect the developmental potential of in vitro-produced embryos, and to test their quality in terms of relative abundance of various genes related to metabolism, apoptosis and oxidation. In the first experiment, in vitro-produced zygotes were cultured in the absence (control [C]) and in the presence of three concentrations of acylated ghrelin (200 pg/mL [Ghr200], 800 pg/mL [Ghr800]; and 2000 pg/mL [Ghr2000]); blastocyst formation rates were examined on Days 7, 8, and 9. In the second experiment, only the 800 pg/mL dose of ghrelin was used. Zygotes were produced as in experiment 1 and 24 hours post insemination they were divided into 4 groups; in two groups (C; without ghrelin; Ghr800 with ghrelin), embryos were cultured without medium replacement; in the remaining two groups (Control N and GhrN), the culture medium was daily renewed. A pool of Day-7 blastocysts were snap frozen for relative mRNA abundance of various genes related to metabolism, oxidation, implantation, and apoptosis. In experiment 3, embryos were produced as in experiment 2, but in the absence of serum (semi-defined culture medium). In experiment 1, no differences were detected between C, Ghr200, and Ghr2000, although fewer blastocysts were produced in group Ghr800 compared with C. In experiment 2, the lowest blastocysts yield was found in Ghr800, whereas daily renewal of ghrelin (Ghr800N) resulted to increased blastocysts formation rate, which on Day 7 was the highest among groups (P < 0.05). In experiment 3, ghrelin significantly suppressed blastocysts yield. Significant differences were detected in various relative mRNA abundance, giving an overall final notion that embryos produced in the

  1. 78 FR 41070 - Notice of Single-Case Deviation from Competition Requirements: Transfer of Grantee Request for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-09

    ... Competition Requirements: Transfer of Grantee Request for the Detroit Healthy Start Program, Detroit, MI... the Detroit Healthy Start Program, Detroit, MI, Grant Number H49MC00147. SUMMARY: HRSA will be issuing... funding level Institute for Population Health... H49MC00147 MI $1,575,000 $1,575,000 Dated: July 2,...

  2. Forced convection heat transfer to a single and two-phase steam/water mixture in a helical coil with radiant heating

    SciTech Connect

    Vafaie, F.N.

    1981-01-01

    The purpose of this study was to perform an analytical and experimental investigation into the heat transfer characteristics for a once-through steam generator with a helical flow geometry. The application is the receiver for a fixed hemispherical mirror solar concentrator on the Crosbyton Solar Power Project. The working fluid, water, goes successively through the single-phase liquid, two-phase and super-heated vapor regimes in a once-through helically wrapped tube bundle subjected to nonuniform asymmetrical radiant heating. Individual segments of the radiation profile for the receiver were simulated using high intensity, line source quartz lamps providing concentrations of up to 240 suns. A segment of the helical coil was instrumented and mounted in the radiation field. A numerical analysis was developed to predict the local internal heat transfer coeffcients and fluid state based on the measurements obtained in the test procedure discussed above. The results show that there is a significant change in the angular variation of the internal heat transfer coefficient at low quality when compared with values for high quality. The integrated average values of the heat transfer coefficient for the subcooled liquid and two-phase were correlated against dimensionless parameters of the flow such as the Reynolds number, Prandtl number, boiling number and tube-to-coil diameter ratio.

  3. The use of single embryo transfer to reduce the incidence of twins: Implications and questions for practice from the 'towardSET?' project.

    PubMed

    Roberts, Stephen A; McGowan, Linda; Vail, Andy; Brison, Daniel R

    2011-06-01

    In vitro fertilisation treatments where multiple embryos are transferred are associated with high multiple birth rates leading to a corresponding high infant morbidity. Here we review the results from a multidisciplinary project which aimed to combine state of the art statistical modelling of routine clinical data with consideration of patient perspectives to explore options for reducing multiple birth incidence by increased use of single embryo transfer (SET). Modelling was based on a large multicentre cohort, supplemented by analysis of HFEA register data. Patient perspectives were explored in qualitative interviews and focus groups. The data confirm the reduction of around one-third in the chance of a live birth for any couple in moving from double embryo transfer (DET) to SET in a fresh cycle. This can be somewhat offset by appropriate patient and cycle selection for SET, with many suggested schemes performing similarly, although many patients perceive such selection as unfair. If we take a complete cycle perspective, and consider the transfer of all good-quality embryos with cryopreservation then it is possible for SET to match or even outperform DET. However, the additional treatment cycles are seen by patients as physically and emotionally burdensome. Such treatments will require optimisation of embryo freezing policies and a number of options are explored.

  4. Transfer-printing of single DNA molecule arrays on graphene for high resolution electron imaging and analysis

    PubMed Central

    Cerf, Aline; Alava, Thomas; Barton, Robert A.; Craighead, Harold G.

    2011-01-01

    Graphene represents the ultimate substrate for high-resolution transmission electron microscopy, but the deposition of biological samples on this highly hydrophobic material has until now been a challenge. We present a reliable method for depositing ordered arrays of individual elongated DNA molecules on single-layer graphene substrates for high resolution electron beam imaging and electron energy loss spectroscopy analysis. This method is a necessary step towards the observation of single elongated DNA molecules with single base spatial resolution to directly read genetic and epigenetic information. PMID:21919532

  5. Fabrication of N-channel single crystalline silicon (100) thin-film transistors on glass substrate by meniscus force-mediated layer transfer technique

    NASA Astrophysics Data System (ADS)

    Akazawa, Muneki; Sakaike, Kohei; Nakamura, Shogo; Higashi, Seiichiro

    2014-10-01

    We propose a novel low-temperature layer transfer of single crystalline silicon (100) to glass substrate using meniscus force and midair cavity structure. Local transfer of thermally-oxidized silicon-on-insulator (SOI) layer to glass was successfully carried out at 80 °C. N-channel thin-film transistor (TFT) fabricated on glass at 300 °C showed a field-effect mobility of 1097 cm2 V-1 s-1, a threshold voltage of 1.1 V and a subthreshold swing value of 78 mV/dec. Raman scattering analysis suggests such a high mobility of TFT is originated from tensile strain introduced after gate SiO2 film deposition.

  6. Nonradiative Energy Transfer from Individual CdSe/ZnS Quantum Dots to Single-Layer and Few-Layer Tin Disulfide

    SciTech Connect

    Zang, Huidong; Routh, Prahlad K.; Huang, Yuan; Chen, Jia-Shiang; Sutter, Eli; Sutter, Peter; Cotlet, Mircea

    2016-03-31

    We study the combination of zero-dimensional (0D) colloidal CdSe/ZnS quantum dots with tin disulfide (SnS2), a two-dimensional (2D)-layered metal dichalcogenide, results in 0D–2D hybrids with enhanced light absorption properties. These 0D–2D hybrids, when exposed to light, exhibit intrahybrid nonradiative energy transfer from photoexcited CdSe/ZnS quantum dots to SnS2. Using single nanocrystal spectroscopy, we find that the rate for energy transfer in 0D–2D hybrids increases with added number of SnS2 layers, a positive manifestation toward the potential functionality of such 2D-based hybrids in applications such as photovoltaics and photon sensing.

  7. A single Tisbnd Osbnd C linkage induces interfacial charge-transfer transitions between TiO2 and a π-conjugated molecule

    NASA Astrophysics Data System (ADS)

    Fujisawa, Jun-ichi; Matsumura, Shingo; Hanaya, Minoru

    2016-07-01

    Interfacial charge-transfer (ICT) transitions between wide-band-gap semiconductors such as titanium dioxide (TiO2) and π-conjugated molecules enable the absorption of visible light with colorless organic compounds and also direct photoinduced electron transfers across the interfaces. ICT transitions have been reported to be induced by a double Tisbnd Osbnd C linkage of enediol compounds with two hydroxy groups to TiO2. In this Letter, we demonstrate that a single Tisbnd Osbnd C linkage of phenol with one hydroxy group can induce ICT transitions in the visible region. Our result widely opens up the range of organic compounds available for ICT transitions from diol compounds to mono-hydroxy compounds.

  8. Nonradiative Energy Transfer from Individual CdSe/ZnS Quantum Dots to Single-Layer and Few-Layer Tin Disulfide

    DOE PAGES

    Zang, Huidong; Routh, Prahlad K.; Huang, Yuan; ...

    2016-03-31

    We study the combination of zero-dimensional (0D) colloidal CdSe/ZnS quantum dots with tin disulfide (SnS2), a two-dimensional (2D)-layered metal dichalcogenide, results in 0D–2D hybrids with enhanced light absorption properties. These 0D–2D hybrids, when exposed to light, exhibit intrahybrid nonradiative energy transfer from photoexcited CdSe/ZnS quantum dots to SnS2. Using single nanocrystal spectroscopy, we find that the rate for energy transfer in 0D–2D hybrids increases with added number of SnS2 layers, a positive manifestation toward the potential functionality of such 2D-based hybrids in applications such as photovoltaics and photon sensing.

  9. The single-molecule conductance and electrochemical electron-transfer rate are related by a power law.

    PubMed

    Wierzbinski, Emil; Venkatramani, Ravindra; Davis, Kathryn L; Bezer, Silvia; Kong, Jing; Xing, Yangjun; Borguet, Eric; Achim, Catalina; Beratan, David N; Waldeck, David H

    2013-06-25

    This study examines quantitative correlations between molecular conductances and standard electrochemical rate constants for alkanes and peptide nucleic acid (PNA) oligomers as a function of the length, structure, and charge transport mechanism. The experimental data show a power-law relationship between conductances and charge transfer rates within a given class of molecules with the same bridge chemistry, and a lack of correlation when a more diverse group of molecules is compared, in contrast with some theoretical predictions. Surprisingly, the PNA duplexes exhibit the lowest charge-transfer rates and the highest molecular conductances. The nonlinear rate-conductance relationships for structures with the same bridging chemistries are attributed to differences in the charge-mediation characteristics of the molecular bridge, energy barrier shifts and electronic dephasing, in the two different experimental settings.

  10. Mass transfer of single- and double-charged anions through an MA-41L anion-exchange membrane

    SciTech Connect

    Kulikova, O.M.; Sharkova, O.V.; Kulikov, S.M.

    1995-02-20

    Selective anion transfer through an MA-41L anion-exchange membrane in the Cl{sup -}-F{sup -}, Cl{sup -}-SO{sub 4}{sup 2-}, F{sup -}-SO{sub 4}{sup 2-}, and F{sup -}-CO{sub 3}{sup 2-} systems has been studied. The feasibility of partial anion separation in the chloride-sulfate system has been demonstrated. The separation of fluoride ions from accompanying anions was found to be practically impossible.

  11. Fusion of blastomeres in mouse embryos under the action of femtosecond laser radiation. Efficiency of blastocyst formation and embryo development

    SciTech Connect

    Osychenko, A A; Zalesskii, A D; Krivokharchenko, A S; Zhakhbazyan, A K; Nadtochenko, V A; Ryabova, A V

    2015-05-31

    Using the method of femtosecond laser surgery we study the fusion of two-cell mouse embryos under the action of tightly focused femtosecond laser radiation with the fusion efficiency reaching 60%. The detailed statistical analysis of the efficiency of blastomere fusion and development of the embryo up to the blastocyst stage after exposure of the embryos from different mice to a femtosecond pulse is presented. It is shown that the efficiency of blastocyst formation essentially depends on the biological characteristics of the embryo, namely, the strain and age of the donor mouse. The possibility of obtaining hexaploid embryonal cells using the methods of femtosecond laser surgery is demonstrated. (extreme light fields and their applications)

  12. Involvement of endometrial membrane sulphydryl groups in blastocyst implantation: sulphydryl groups as a potential target for contraceptive research.

    PubMed

    Nivsarkar, M; Sethi, A; Bapu, C; Patel, M; Padh, H

    2001-10-01

    The role of membrane sulphydryl groups in blastocyst implantation was studied by masking the membrane sulphydryl groups in the endometrium of Swiss albino mice, Mus musculus, using 10(-5) M cobalt chloride and 0.05 mM as well as 0.005 mM n-ethylmaleimide. Here we show that the blocking of sulphydryl groups with cobalt resulted in a decrease in superoxide radical surge and an increase in superoxide dismutase levels at the time of implantation. We hypothesize that it may be due to either a decrease in membrane fluidity or the unavailability of sulphydryl groups of endometrial membrane, thus preventing blastocyst implantation. These sulphydryl groups can be targeted for future contraceptive research.

  13. DNA methylation in the IGF2 intragenic DMR is re-established in a sex-specific manner in bovine blastocysts after somatic cloning.

    PubMed

    Gebert, Claudia; Wrenzycki, Christine; Herrmann, Doris; Gröger, Daniela; Thiel, Janina; Reinhardt, Richard; Lehrach, Hans; Hajkova, Petra; Lucas-Hahn, Andrea; Carnwath, Joseph W; Niemann, Heiner

    2009-07-01

    The recent identification of an intragenic differentially methylated region (DMR) within the last exon of the bovine Insulin-like growth factor 2 (IGF2) gene provides a diagnostic tool for in-depth investigation of bovine imprinting and regulatory mechanisms which are active during embryo development. Here, we used bisulfite sequencing to compare sex-specific DNA methylation patterns within this DMR in bovine blastocysts produced in vivo, by in vitro fertilization and culture, SCNT, androgenesis or parthenogenesis. In in vivo derived embryos, DNA methylation was removed from this intragenic DMR after fertilization, but partially replaced by the time the embryo reached the blastocyst stage. Among embryos developing in vivo, the level of DNA methylation was significantly lower in female than in male blastocysts. This sexual dimorphism was also found between parthenogenetic and androgenetic embryos, and followed the donor cell sex in SCNT derived blastocysts and is evidence for correct methylation reprogramming in SCNT embryos.

  14. Interspecies Dissemination of a Mobilizable Plasmid Harboring blaIMP-19 and the Possibility of Horizontal Gene Transfer in a Single Patient

    PubMed Central

    Gomi, Ryota; Matsuda, Tomonari; Tanaka, Michio; Nagao, Miki; Takakura, Shunji; Uemoto, Shinji; Ichiyama, Satoshi

    2016-01-01

    Carbapenemase-producing Gram-negative bacilli have been a global concern over the past 2 decades because these organisms can cause severe infections with high mortality rates. Carbapenemase genes are often carried by mobile genetic elements, and resistance plasmids can be transferred through conjugation. We conducted whole-genome sequencing (WGS) to demonstrate that the same plasmid harboring a metallo-β-lactamase gene was detected in two different species isolated from a single patient. Metallo-β-lactamase-producing Achromobacter xylosoxidans (KUN4507), non-metallo-β-lactamase-producing Klebsiella pneumoniae (KUN4843), and metallo-β-lactamase-producing K. pneumoniae (KUN5033) were sequentially isolated from a single patient and then analyzed in this study. Antimicrobial susceptibility testing, molecular typing (pulsed-field gel electrophoresis and multilocus sequence typing), and conjugation analyses were performed by conventional methods. Phylogenetic and molecular clock analysis of K. pneumoniae isolates were performed with WGS, and the nucleotide sequences of plasmids detected from these isolates were determined using WGS. Conventional molecular typing revealed that KUN4843 and KUN5033 were identical, whereas the phylogenetic tree analysis revealed a slight difference. These two isolates were separated from the most recent common ancestor 0.74 years before they were isolated. The same resistance plasmid harboring blaIMP-19 was detected in metallo-β-lactamase-producing A. xylosoxidans and K. pneumoniae. Although this plasmid was not self-transferable, the conjugation of this plasmid from A. xylosoxidans to non-metallo-β-lactamase-producing K. pneumoniae was successfully performed. The susceptibility patterns for metallo-β-lactamase-producing K. pneumoniae and the transconjugant were similar. These findings supported the possibility of the horizontal transfer of plasmid-borne blaIMP-19 from A. xylosoxidans to K. pneumoniae in a single patient. PMID

  15. Cumulative success rates following mild IVF in unselected infertile patients: a 3-year, single-centre cohort study.

    PubMed

    Bodri, Daniel; Kawachiya, Satoshi; De Brucker, Michaël; Tournaye, Herman; Kondo, Masae; Kato, Ryutaro; Matsumoto, Tsunekazu

    2014-05-01

    A 3-year, retrospective, single-centre cohort study was conducted in a private infertility centre to determine cumulative live birth rates (LBR) per scheduled oocyte retrieval following minimal ovarian stimulation/natural-cycle IVF in unselected infertile patients. A total of 727 consecutive infertile patients were analysed who underwent 2876 (median 4) cycles with scheduled oocyte retrieval from November 2008 to December 2011. Natural-cycle IVF or clomiphene-based minimal ovarian stimulation was coupled with single-embryo transfer and increased use of delayed vitrified-warmed blastocyst transfer. Main outcome measures were crude and expected age-specific cumulative LBR per scheduled oocyte retrieval. Crude cumulative LBR were 65%, 60%, 39%, 15% and 5% in patients aged 26-34, 35-37, 38-40, 41-42 and 43-44 years, respectively. No live births occurred in patients aged ⩾ 45 years. Dropout rates per cycle were 13-25%. Success rates gradually reached a plateau, with few additional live births after six cycles. Most of the expected success rate was reached within 6 months with almost maximal rates within 15 months of the first oocyte retrieval. Acceptable cumulative LBR are reached with an exclusive minimal ovarian stimulation/single-embryo transfer policy especially in patients aged <38 years but also in intermediate aged patients (38-40 years).

  16. Highly Efficient Simplified Single-Emitting-Layer Hybrid WOLEDs with Low Roll-off and Good Color Stability through Enhanced Förster Energy Transfer.

    PubMed

    Zhang, Dongdong; Cai, Minghan; Zhang, Yunge; Zhang, Deqiang; Duan, Lian

    2015-12-30

    Single-emitting layer hybrid white organic light-emitting diodes (SEL-hybrid-WOLEDs) usually suffer from low efficiency, significant roll-off, and poor color stability, attributed to the incomplete energy transfer from the triplet states of the blue fluorophores to the phosphors. Here, we demonstrate highly efficient SEL-hybrid-WOLEDs with low roll-off and good color-stability utilizing blue thermally activated delayed fluorescence (TADF) materials as the host emitters. The triplet states of the blue TADF host emitter can be up-converted into its singlet states, and then the energy is transferred to the complementary phosphors through the long-range Förster energy transfer, enhancing the energy transfer from the host to the dopant. Simplified SEL-hybrid-WOLEDs achieve the highest forward-viewing external quantum efficiency (EQE) of 20.8% and power efficiency of 51.2 lm/W with CIE coordinates of (0.398, 0.456) at a luminance of 500 cd/m(2). The device EQE only slightly drops to 19.6% at a practical luminance of 1000 cd/m(2) with a power efficiency of 38.7 lm/W. Furthermore, the spectra of the device are rather stable with the raising voltage. The reason can be assigned to the enhanced Förster energy transfer, wide charge recombination zone, as well as the bipolar charge transporting ability of the host emitter. We believe that our work may shed light on the future development of highly efficient SEL-hybrid-WOLEDs with simultaneous low roll-off and good color stability.

  17. Selenium and vitamin E improve the in vitro maturation, fertilization and culture to blastocyst of porcine oocytes.

    PubMed

    Tareq, K M A; Akter, Quzi Sharmin; Khandoker, M A M Yahia; Tsujii, Hirotada

    2012-01-01

    Selenium (Se) and vitamin E (Vit-E), as integral parts of antioxidant systems, play important roles for sperm and embryos in vitro. In this study, the effects of Se and Vit-E on the maturation, in vitro fertilization and culture to blastocysts of porcine oocytes and accumulation of ammonia in the culture medium during different development stages were investigated. The maturation was performed in modified tissue culture medium (mTCM)-199 supplemented with 10% (v/v) porcine follicular fluid, the fertilization medium was modified Tyrode's albumin lactate pyruvate (mTALP), and the embryo culture medium was modified North Carolina State University (mNCSU)-23. Se in the form of sodium selenite (SS) and seleon-L-methionine (SeMet) and Vit-E at different concentrations were also used. The incorporation and oxidation of (14)C(U)-glucose were assessed with a liquid scintillation counter. In this study, SeMet and SeMet+Vit-E increased oocyte maturation, fertilization and incorporation and oxidation of (14)C(U)-glucose significantly (P<0.05) compared with the control and other treatments. In addition, embryo development, specifically in terms of the numbers of morulae and blastocysts, significantly increased (P<0.05) with SeMet and SeMet+Vit-E. In contrast, the accumulation of ammonia was reduced with SeMet and SeMet+Vit-E compared with other treatments. These findings indicate that SeMet and SeMet+Vit-E may play important roles in reducing the accumulation of ammonia and subsequently in increasing the rate of maturation of porcine oocytes and fertilization, as well as development of the blastocyst and utilization of glucose in in vitro maturation, fertilization and culture to blastocysts of porcine oocytes.

  18. The incorporation and distribution of some heavy metals in mouse blastocysts after intravenous administration. A micro-PIXE application

    NASA Astrophysics Data System (ADS)

    Lindh, Ulf; Nilsson, Ove

    1984-04-01

    The study of heavy metal incorporation into ovi or embryos via the blood of the mother is of great interest to assess the health effects of occupational exposure. Such studies have not been possible on human material. Thus the mouse was chosen as a model for this study. The Studsvik Nuclear Microprobe was used to assess the blastocyst contents of heavy metals. For some of the metals administered to the animals substantial amounts could be revealed in the embryonic tissue.

  19. Scriptaid Upregulates Expression of Development-Related Genes, Inhibits Apoptosis, and Improves the Development of Somatic Cell Nuclear Transfer Mini-Pig Embryos.

    PubMed

    Zhang, Li; Huang, Yuemeng; Wu, Yanjun; Si, Jinglei; Huang, Yanna; Jiang, Qinyang; Lan, Ganqiu; Guo, Yafen; Jiang, Hesheng

    2017-02-01

    The present study was undertaken to investigate the mechanisms by which Scriptaid treatment improves the developmental competence of somatic cell nuclear transfer (SCNT) mini-pig embryos in vitro. We found that treatment with 500 nmol/L Scriptaid for 15 hours significantly improved the development of mini-pig SCNT embryos. Compared with the control group, the blastocyst rate was higher (18.3% vs. 10.7%; p < 0.05). The acetylation level on H3K14 of the Scriptaid-treated group was higher compared with the control group in SCNT embryos at two-cell, four-cell, and blastocyst stages (p < 0.05). After Scriptaid treatment, histone deacetylase gene HDAC5 expression level was significantly decreased in four-cell embryos and blastocysts, while the expression levels of the embryos' development-related genes AKT, Oct4, and apoptosis inhibited gene PGC-1α were significantly increased in blastocysts (p < 0.05). The number of apoptotic cells per blastocyst in the Scriptaid-treated group was lower compared with the control group (p < 0.05). These results indicate that Scriptaid repressed HDCA5 gene expression, increased the acetylation level of H3K14, upregulated the expression of AKT, Oct4, and PGC-1α genes, improved embryos' development, and reduced apoptosis, which favors development of the SCNT mini-pig embryos to blastocysts.

  20. Melatonin improves the quality of in vitro produced (IVP) bovine embryos: implications for blastocyst development, cryotolerance, and modifications of relevant gene expression.

    PubMed

    Wang, Feng; Tian, XiuZhi; Zhou, YanHua; Tan, DunXian; Zhu, ShiEn; Dai, YunPing; Liu, GuoShi

    2014-01-01

    To evaluate the potential effects of melatonin on the kinetics of embryo development and quality of blastocyst during the process of in vitro bovine embryo culture. Bovine cumulus-oocyte complexes (COCs) were fertilized after in vitro maturation. The presumed zygotes were cultured in in vitro culture medium supplemented with or without 10(-7) M melatonin. The cleavage rate, 8-cell rate and blastocyst rate were examined to identify the kinetics of embryo development. The hatched blastocyst rate, mortality rate after thawing and the relevant transcript abundance were measured to evaluate the quality of blastocyst. The results showed that melatonin significantly promoted the cleavage rate and 8-cell embryo yield of in vitro produced bovine embryo. In addition, significantly more blastocysts were observed by Day 7 of embryo culture at the presence of melatonin. These results indicated that melatonin accelerated the development of in vitro produced bovine embryos. Following vitrification at Day 7 of embryo culture, melatonin (10(-7) M) significantly increased the hatched blastocyst rate from 24 h to 72 h and decreased the mortality rate from 48 h to 72 h after thawing. The presence of melatonin during the embryo culture resulted in a significant increase in the gene expressions of DNMT3A, OCC, CDH1 and decrease in that of AQP3 after thawing. In conclusion, melatonin not only promoted blastocyst yield and accelerated in vitro bovine embryo development, but also improved the quality of blastocysts which was indexed by an elevated cryotolerance and the up-regulated expressions of developmentally important genes.

  1. Trichostatin A affects histone acetylation and gene expression in porcine somatic cell nucleus transfer embryos.

    PubMed

    Cervera, R P; Martí-Gutiérrez, N; Escorihuela, E; Moreno, R; Stojkovic, M

    2009-11-01

    Epigenetic aberrancies likely preclude correct and complete nuclear reprogramming after somatic cell nucleus transfer (SCNT) and may underlie the observed reduced viability of cloned embryos. In the current study, we tested the effects of the histone deacetylase-inhibitor trichostatin A (TSA) on preimplantation development and on histone acetylation and the gene expression of nucleus transfer (NT) porcine (Sus scrofa) embryos. Our results showed that 5 nM TSA for 26 h after reconstitution resulted in embryos (NTTSA) that reached the blastocyst stage at a higher level (48.1% vs. 20.2%) and increased number of cells (105.0 vs. 75.3) than that of the control (NTC) embryos. In addition, and unlike the NTC embryos, the treated embryos displayed a global acetylated histone H4 at lysine 8 profile similar to the in vitro-fertilized (IVF) and cultured embryos during the preimplantation development. Finally, we determined that several transcription factors exert a dramatic amount of genetic control over pluripotency, including Oct4, Nanog, Cdx2, and Rex01, the imprinting genes Igf2 and Igf2r, and the histone deacetyltransferase gene Hdac2. The NT blastocysts showed similar levels of Oct4, Cdx2, and Hdac2 but lower levels of Nanog than those of the IVF blastocyst. However, the NTTSA blastocysts showed similar levels of Rex01, Igf2, and Igf2r as those of IVF blastocysts, whereas the NTC blastocysts showed significantly lower levels for those genes. Our results suggest that TSA improves porcine SCNT preimplantation development and affects the acetylated status of the H4K8, rendering acetylation levels similar to those of the IVF counterparts.

  2. Imaging proprotein convertase activities and their regulation in the implanting mouse blastocyst.

    PubMed

    Mesnard, Daniel; Constam, Daniel B

    2010-10-04

    Axis formation and allocation of pluripotent progenitor cells to the germ layers are governed by the TGF-β-related Nodal precursor and its secreted proprotein convertases (PCs) Furin and Pace4. However, when and where Furin and Pace4 first become active have not been determined. To study the distribution of PCs, we developed a novel cell surface-targeted fluorescent biosensor (cell surface-linked indicator of proteolysis [CLIP]). Live imaging of CLIP in wild-type and Furin- and Pace4-deficient embryonic stem cells and embryos revealed that Furin and Pace4 are already active at the blastocyst stage in the inner cell mass and can cleave membrane-bound substrate both cell autonomously and nonautonomously. CLIP was also cleaved in the epiblast of implanted embryos, in part by a novel activity in the uterus that is independent of zygotic Furin and Pace4, suggesting a role for maternal PCs during embryonic development. The unprecedented sensitivity and spatial resolution of CLIP opens exciting new possibilities to elucidate PC functions in vivo.

  3. Oxytocin receptor is differentially expressed in mouse endometrium and embryo during blastocyst implantation.

    PubMed

    Beretsos, Panagiotis; Loutradis, Dimitris; Koussoulakos, Stauros; Margaritis, Loukas H; Kiapekou, Erasmia; Mastorakos, George; Papaspirou, Irini; Makris, Nikolaos; Makrigiannakis, Antonis; Antsaklis, Aris

    2006-12-01

    The oxytocin (OT)-oxytocin receptor (OTR) system of the mammalian uterus has mainly been studied in relation to its involvement in the onset of labor. The aim of this study was to elucidate the in vivo expression and localization pattern of OTR in the mouse endometrium and embryo during implantation, as well as OTR mRNA expression in the in vitro developing mouse embryo. The expression of OTR or OT was detected immunohistochemically in uterine tissue sections of 5- to 8-week-old female mice between days 4 and 10 of an established pregnancy. In addition, the expression of OTR mRNA was detected by means of reverse transcription polymerase chain reaction (RT-PCR) in mouse oocytes and embryos up to the blastocyst stage. The mean ratios of normalized expression levels of OTR gene in all samples were also calculated. The recorded increase in OTR mRNA immediately after fertilization could mean a possible role of OT in this process, as OTR mRNA gradually decreased after the four-cell stage of pre-embryonic development. The differential expression of OTR during embryonic apposition and embryonic invasion/placentation in the mouse uterus suggests a potential role of OT in the implantation process of the mouse. It is possible that the interaction of OTR with the hormones included in the ovulation induction regiments utilized today in in vitro fertilization (IVF) could be affecting the receptivity/quality of the implanting endometrium.

  4. Free blastocyst and implantation stages in the European brown hare: correlation between ultrasound and histological data.

    PubMed

    Drews, Barbara; Ringleb, Jennifer; Waurich, Romy; Hildebrandt, Thomas Bernd; Schröder, Katharina; Roellig, Kathleen

    2013-01-01

    The European brown hare (Lepus europaeus) is the only species with superconception, whereby the maternal reproductive tract hosts two sets of conceptuses at different developmental stages. The embryonic development of the hare has not yet been described. To understand the mechanism of superconception, we studied oviduct transport and implantation stages by embryo flushing and live high-resolution ultrasound. Ultrasound data of implantation stages is correlated with histology. In the oviduct, a mucin coat is deposited on the zona pellucida. The blastocysts enter the uterine horns on Day 5, 1 day later than in the rabbit, and directly expand approximately threefold. Spacing is accompanied by peristaltic movement of the endometrium. The mucin coat disappears and the conceptuses attach. The yolk-sac expands in the blastocoel and syncytial knobs invade the antimesometrial endometrium. Maternal blood lacunae appear in the mesometrial endometrial folds, which are subsequently invaded by the syncytiotrophoblast. The haemochorial chorioallantoic placenta forms. The yolk-sac cavity is gradually replaced by the allantois and finally by the exocoel. The different reproductive strategies of the precocial hare and the altricial rabbit are discussed. We assume that the lagomorph-specific mucin coat and the hare-specific delay of the oviduct-uterine transition are prerequisites for superconception.

  5. Maternal-zygotic knockout reveals a critical role of Cdx2 in the morula to blastocyst transition.

    PubMed

    Jedrusik, Agnieszka; Cox, Andy; Wicher, Krzysztof B; Glover, David M; Zernicka-Goetz, Magdalena

    2015-02-15

    The first lineage segregation in the mouse embryo generates the inner cell mass (ICM), which gives rise to the pluripotent epiblast and therefore the future embryo, and the trophectoderm (TE), which will build the placenta. The TE lineage depends on the transcription factor Cdx2. However, when Cdx2 first starts to act remains unclear. Embryos with zygotic deletion of Cdx2 develop normally until the late blastocyst stage leading to the conclusion that Cdx2 is important for the maintenance but not specification of the TE. In contrast, down-regulation of Cdx2 transcripts from the early embryo stage results in defects in TE specification before the blastocyst stage. Here, to unambiguously address at which developmental stage Cdx2 becomes first required, we genetically deleted Cdx2 from the oocyte stage using a Zp3-Cre/loxP strategy. Careful assessment of a large cohort of Cdx2 maternal-zygotic null embryos, all individually filmed, examined and genotyped, reveals an earlier lethal phenotype than observed in Cdx2 zygotic null embryos that develop until the late blastocyst stage. The developmental failure of Cdx2 maternal-zygotic null embryos is associated with cell death and failure of TE specification, starting at the morula stage. These results indicate that Cdx2 is important for the correct specification of TE from the morula stage onwards and that both maternal and zygotic pools of Cdx2 are required for correct pre-implantation embryogenesis.

  6. Tight junction protein ZO-2 expression and relative function of ZO-1 and ZO-2 during mouse blastocyst formation

    SciTech Connect

    Sheth, Bhavwanti; Nowak, Rachael L.; Anderson, Rebecca; Kwong, Wing Yee; Papenbrock, Thomas; Fleming, Tom P.

    2008-11-01

    Apicolateral tight junctions (TJs) between epithelial cells are multiprotein complexes regulating membrane polarity and paracellular transport and also contribute to signalling pathways affecting cell proliferation and gene expression. ZO-2 and other ZO family members form a sub-membranous scaffold for binding TJ constituents. We investigated ZO-2 contribution to TJ biogenesis and function during trophectoderm epithelium differentiation in mouse preimplantation embryos. Our data indicate that ZO-2 is expressed from maternal and embryonic genomes with maternal ZO-2 protein associated with nuclei in zygotes and particularly early cleavage stages. Embryonic ZO-2 assembled at outer blastomere apicolateral junctional sites from the late 16-cell stage. Junctional ZO-2 first co-localised with E-cadherin in a transient complex comprising adherens junction and TJ constituents before segregating to TJs after their separation from the blastocyst stage (32-cell onwards). ZO-2 siRNA microinjection into zygotes or 2-cell embryos resulted in specific knockdown of ZO-2 mRNA and protein within blastocysts. Embryos lacking ZO-2 protein at trophectoderm TJs exhibited delayed blastocoel cavity formation but underwent normal cell proliferation and outgrowth morphogenesis. Quantitative analysis of trophectoderm TJs in ZO-2-deficient embryos revealed increased assembly of ZO-1 but not occludin, indicating ZO protein redundancy as a compensatory mechanism contributing to the mild phenotype observed. In contrast, ZO-1 knockdown, or combined ZO-1 and ZO-2 knockdown, generated a more severe inhibition of blastocoel formation indicating distinct roles for ZO proteins in blastocyst morphogenesis.

  7. Influence of Single Skimmer Versus Dual Funnel Transfer on the Appearance of ESI-Generated LiCl Cluster/ß-Cyclodextrin Inclusion Complexes

    NASA Astrophysics Data System (ADS)

    Kellner, Ina D.; Drewello, Thomas

    2015-08-01

    Singly and doubly charged adducts of LiCl with β-cyclodextrin (βCD) of the type (βCD)(LiCl)nLi+ and (βCD)2(LiCl)pLi2 2+ were studied using electrospray ionization mass spectrometry (ESI-MS). Insight into their structural composition was gained by analysis of their collision-induced dissociation (CID) mass spectra. The conditions the ions experience in the transfer region interfacing the ESI source and the mass analyzer were found to have a marked influence on the nature of the detected ions. In one instrument incorporating a single skimmer, individually attached LiCl ion pairs were observed, whereas the dual funnel ion guides of the second instrument allow the detection of previously unknown labile inclusion complexes of (LiCl)n clusters in βCD.

  8. Silver transfer in proustite Ag{sub 3}AsS{sub 3} at high temperatures: Conductivity and single-crystal X-ray studies

    SciTech Connect

    Gagor, Anna Pawlowski, Antoni; Pietraszko, Adam

    2009-03-15

    Single crystals of proustite Ag{sub 3}AsS{sub 3} have been characterised by impedance spectroscopy and single-crystal X-ray diffraction in the temperature ranges of 295-543 and 295-695 K, respectively. An analysis of the one-particle potential of silver atoms shows that in the whole measuring temperature range defects in the silver substructure play a major role in the conduction mechanism. Furthermore, the silver transfer is equally probable within silver chains and spirals, as well as between chains and spirals. The trigonal R3c room temperature phase does not change until the decomposition of the crystal. The electric anomaly of the first-order character which appears near 502 K is related to an increase in the electronic component of the total conductivity resulting from Ag{sub 2}S deposition at the sample surface. - Joint probability density function map of silver atoms at T=695 K.

  9. Pregnancy rate following transfer of in vitro produced lamb derived embryos in two embryonic stages.

    PubMed

    Shirazi, A; Shams-Esfandabadi, N; Ahmadi, E; Jadidi, M; Heidari, B

    2008-03-15

    Ovine embryos were produced by maturation, fertilization and in vitro culture (IVM/IVF/IVC) of oocytes collected from slaughtered prepubertal ewes. At 24 h post IVM, oocytes were fertilized with fresh semen collected from Lori-Bakhtiari breed at a concentration of 1.0 x l0(6) sperm mL(-1). The presumptive ova/embryos were transferred into the embryo culture medium at 22-24 h post IVF. Following 4 to 7 day in culture, embryos (at morula and blastocyst stage, respectively) were transferred surgically to the uterine horn of synchronized recipients. Pregnancy was diagnosed at day 30 by hormonal assay and at days 55 and 140 of gestation by ultrasonography and pregnancies were allowed to go to term. A total of nine ewes received 27 embryos (3 embryos/ewe). Five ewes received 15 embryos at morula stage and four ewes received 12 embryos at blastocyst stage. From those received morula stage embryos one was pregnant on day 30 (20%), though no pregnancy was diagnosed on each of days 55 and 140. While from those received blastocyst stage embryos, three ewes were pregnant on day 30 (75%) and two ewes (50%) remained pregnant on each of days 55 and 140. In conclusion, day 4 IVM-IVF morula stage embryos had a lower survival rate than did day 7 IVM-IVF blastocysts embryos, following transfer to the synchronized recipient ewes.

  10. Mid-luteal serum progesterone concentrations govern implantation rates for cryopreserved embryo transfers conducted under hormone replacement.

    PubMed

    Yovich, John L; Conceicao, Jason L; Stanger, James D; Hinchliffe, Peter M; Keane, Kevin N

    2015-08-01

    This study explores the relevance of mid-luteal serum hormonal concentrations in cryopreserved embryo transfer cycles conducted under hormone replacement therapy (HRT) control and which involved single-embryo transfer (SET) of 529 vitrified blastocysts. Widely ranging mid-luteal oestradiol and progesterone concentrations ensued from the unique HRT regimen. Oestradiol had no influence on clinical pregnancy or live birth rates, but an optimal progesterone range between 70 and 99 nmol/l (P < 0.005) was identified in this study. Concentrations of progesterone below 50 nmol/l and above 99 nmol/l were associated with decreased implantation rates. There was no clear interaction between oestradiol and progesterone concentrations but embryo quality grading did show a significant influence on outcomes (P < 0.001 and P = 0.002 for clinical pregnancy and live birth rates, respectively). Multiple comparison analysis showed that the progesterone effect was influential regardless of embryo grading, body mass index or the woman's age, either at vitrification or at cryopreserved embryo transfer. The results support the argument that careful monitoring of serum progesterone concentrations in HRT-cryopreserved embryo transfer is warranted and that further studies should explore pessary adjustments to optimize concentrations for individual women to enhance implantation rates.

  11. Large aperture deformable mirror with a transferred single-crystal silicon membrane actuated using large-stroke PZT Unimorph Actuators

    NASA Technical Reports Server (NTRS)

    Hishinumat, Yoshikazu; Yang, Eui - Hyeok (EH)

    2005-01-01

    We have demonstrated a large aperture (50 mm x 50 mm) continuous membrane deformable mirror (DM) with a large-stroke piezoelectric unimorph actuator array. The DM consists of a continuous, large aperture, silicon membrane 'transferred' in its entirety onto a 20 x 20 piezoelectric unimorph actuator array. A PZT unimorph actuator, 2.5 mm in diameter with optimized PZT/Si thickness and design showed a deflection of 5.7 [m at 20V. An assembled DM showed an operating frequency bandwidth of 30 kHz and influence function of approximately 30%.

  12. A Critical Evaluation of Studies Employing Alkenyl Halide ’Mechanistic Probe’ as Indicators of Single Electron Transfer Processes.

    DTIC Science & Technology

    1987-07-07

    continuJe on fevers* or r~ecesry andw aenn’fy oy 0ole riumooerl electron transfer mechanistic probes free rdcl OROUP SB-GROUP kinetics radicls ) ’ 8...8217 which are free from complication. IFI AaS7;A’ 21~O~ -13SqA 7 SOrleti CA ,C Uncasified casife "a 0 2EP01 S,3_: N IVIUAL2,b -EEP OIEIroiud Are koc) 2...useful in evaluating the accuracy of past conclusions drawn from alkenyl halide probe experiments and in designing future experiments which are free

  13. 2.0-μm emission and energy transfer of Ho3+/Yb3+ co-doped LiYF4 single crystal excited by 980 nm

    NASA Astrophysics Data System (ADS)

    Yang, Shuo; Xia, Hai-Ping; Jiang, Yong-Zhang; Zhang, Jia-Zhong; Jiang, Dong-Sheng; Wang, Cheng; Feng, Zhi-Gang; Zhang, Jian; Gu, Xue-Mei; Zhang, Jian-Li; Jiang, Hao-Chuan; Chen, Bao-Jiu

    2015-06-01

    Ho3+/Yb3+ co-doped LiYF4 single crystals with various Yb3+ concentrations and ˜ 0.98 mol% Ho3+ concentration are grown by the Bridgman method under the conditions of taking LiF and YF3 as raw materials and a temperature gradient (40 °C/cm-50 °C/cm) for the solid-liquid interface. The luminescent performances of the crystals are investigated through emission spectra, infrared transmittance spectrum, emission cross section, and decay curves under excitation by 980 nm. Compared with the Ho3+ single-doped LiYF4 crystal, the Ho3+/Yb3+ co-doped LiYF4 single crystal has an obviously enhanced emission band from 1850 nm to 2150 nm observed when excited by a 980-nm diode laser. The energy transfer from Yb3+ to Ho3+ and the optimum fluorescence emission around 2.0 μm of Ho3+ ions are investigated. The maximum emission cross section of the above sample at 2.0 μm is calculated to be 1.08×10-20 cm2 for the LiYF4 single crystal of 1-mol% Ho3+ and 6-mol% Yb3+ according to the measured absorption spectrum. The high energy transfer efficiency of 88.9% from Yb3+ to Ho3+ ion in the sample co-doped by Ho3+ (1 mol%) and Yb3+ (8 mol%) demonstrates that the Yb3+ ions can efficiently sensitize the Ho3+ ions. Project supported by the National Natural Science Foundation of China (Grant Nos. 51472125 and 51272109) and the K.C. Wong Magna Fund in Ningbo University, China (Grant No. NBUWC001).

  14. Costs of achieving live birth from assisted reproductive technology: a comparison of sequential single and double embryo transfer approaches

    PubMed Central

    Crawford, Sara; Boulet, Sheree L.; Mneimneh, Allison S.; Perkins, Kiran M.; Jamieson, Denise J.; Zhang, Yujia; Kissin, Dmitry M.

    2016-01-01

    Objective To assess treatment and pregnancy/infant-associated medical costs and birth outcomes for assisted reproductive technology (ART) cycles in a subset of patients using elective double embryo (ET) and to project the difference in costs and outcomes had the cycles instead been sequential single ETs (fresh followed by frozen if the fresh ET did not result in live birth). Design Retrospective cohort study using 2012 and 2013 data from the National ART Surveillance System. Setting Infertility treatment centers. Patient(s) Fresh, autologous double ETs performed in 2012 among ART patients younger than 35 years of age with no prior ART use who cryopreserved at least one embryo. Intervention(s) Sequential single and double ETs. Main Outcome Measure(s) Actual live birth rates and estimated ART treatment and pregnancy/infant-associated medical costs for double ET cycles started in 2012 and projected ART treatment and pregnancy/infant-associated medical costs if the double ET cycles had been performed as sequential single ETs. Result(s) The estimated total ART treatment and pregnancy/infant-associated medical costs were $580.9 million for 10,001 double ETs started in 2012. If performed as sequential single ETs, estimated costs would have decreased by $195.0 million to $386.0 million, and live birth rates would have increased from 57.7%–68.0%. Conclusion(s) Sequential single ETs, when clinically appropriate, can reduce total ART treatment and pregnancy/infant-associated medical costs by reducing multiple births without lowering live birth rates. PMID:26604068

  15. pH-Sensitive photoinduced energy transfer from bacteriorhodopsin to single-walled carbon nanotubes in SWNT-bR hybrids.

    PubMed

    El Hadj, Karim; Bertoncini, Patricia; Chauvet, Olivier

    2013-10-22

    Energy transfer mechanisms in noncovalently bound bacteriorhodopsin/single-walled carbon nanotube (SWNT) hybrids are investigated using optical absorption and photoluminescence excitation measurements. The morphology of the hybrids was investigated by atomic force microscopy. In this study, proteins are immobilized onto the sidewall of the carbon nanotubes using a sodium cholate suspension-dialysis method that maintains the intrinsic optical and fluorescence properties of both molecules. The hybrids are stable in aqueous solutions for pH ranging from 4.2 to 9 and exhibit photoluminescence properties that are pH-dependent. The study reveals that energy transfer from bacteriorhodopsin to carbon nanotubes takes place. So, at pH higher than 5 and up to 9, the SWNTs absorb the photons emitted by the aromatic residues of the protein, inducing a strong increase in intensity of the E11 emissions of SWNTs through their E33 and E44 excitations. From pH = 4.2 to pH = 5, the protein fluorescence is strongly quenched whatever the emission wavelengths, while additional fluorescence features appear at excitation wavelengths ranging from 660 to 680 nm and at 330 nm. The presence of these features is attributed to a resonance energy transfer mechanism that has an efficiency of 0.94 ± 0.02. More, by increasing the pH of the dispersion, the fluorescence characteristics become those observed at higher pH values and vice versa.

  16. Meniscus-force-mediated layer transfer technique using single-crystalline silicon films with midair cavity: Application to fabrication of CMOS transistors on plastic substrates

    NASA Astrophysics Data System (ADS)

    Sakaike, Kohei; Akazawa, Muneki; Nakagawa, Akitoshi; Higashi, Seiichiro

    2015-04-01

    A novel low-temperature technique for transferring a silicon-on-insulator (SOI) layer with a midair cavity (supported by narrow SiO2 columns) by meniscus force has been proposed, and a single-crystalline Si (c-Si) film with a midair cavity formed in dog-bone shape was successfully transferred to a poly(ethylene terephthalate) (PET) substrate at its heatproof temperature or lower. By applying this proposed transfer technique, high-performance c-Si-based complementary metal-oxide-semiconductor (CMOS) transistors were successfully fabricated on the PET substrate. The key processes are the thermal oxidation and subsequent hydrogen annealing of the SOI layer on the midair cavity. These processes ensure a good MOS interface, and the SiO2 layer works as a “blocking” layer that blocks contamination from PET. The fabricated n- and p-channel c-Si thin-film transistors (TFTs) on the PET substrate showed field-effect mobilities of 568 and 103 cm2 V-1 s-1, respectively.

  17. Transfer characteristics and low-frequency noise in single- and multi-layer MoS{sub 2} field-effect transistors

    SciTech Connect

    Sharma, Deepak; Motayed, Abhishek; Shah, Pankaj B.; Amani, Matin; Georgieva, Mariela; Glen Birdwell, A.; Dubey, Madan; Li, Qiliang; Davydov, Albert V.

    2015-10-19

    Leveraging nanoscale field-effect transistors (FETs) in integrated circuits depends heavily on its transfer characteristics and low-frequency noise (LFN) properties. Here, we report the transfer characteristics and LFN in FETs fabricated with molybdenum disulfide (MoS{sub 2}) with different layer (L) counts. 4L to 6L devices showed highest I{sub ON}-I{sub OFF} ratio (≈10{sup 8}) whereas LFN was maximum for 1L device with normalized power spectral density (PSD) ≈1.5 × 10{sup −5 }Hz{sup −1}. For devices with L ≈ 6, PSD was minimum (≈2 × 10{sup −8 }Hz{sup −1}). Further, LFN for single and few layer devices satisfied carrier number fluctuation (CNF) model in both weak and strong accumulation regimes while thicker devices followed Hooge's mobility fluctuation model in the weak accumulation regime and CNF model in strong accumulation regime, respectively. Transfer-characteristics and LFN experimental data are explained with the help of model incorporating Thomas-Fermi charge screening and inter-layer resistance coupling.

  18. Single-event and total-dose effects in geo-stationary transfer orbit during solar-activity maximum period measured by the Tsubasa satellite

    NASA Astrophysics Data System (ADS)

    Koshiishi, H.; Kimoto, Y.; Matsumoto, H.; Goka, T.

    The Tsubasa satellite developed by the Japan Aerospace Exploration Agency was launched in Feb 2002 into Geo-stationary Transfer Orbit GTO Perigee 500km Apogee 36000km and had been operated well until Sep 2003 The objective of this satellite was to verify the function of commercial parts and new technologies of bus-system components in space Thus the on-board experiments were conducted in the more severe radiation environment of GTO rather than in Geo-stationary Earth Orbit GEO or Low Earth Orbit LEO The Space Environment Data Acquisition equipment SEDA on board the Tsubasa satellite had the Single-event Upset Monitor SUM and the DOSimeter DOS to evaluate influences on electronic devices caused by radiation environment that was also measured by the particle detectors of the SEDA the Standard DOse Monitor SDOM for measurements of light particles and the Heavy Ion Telescope HIT for measurements of heavy ions The SUM monitored single-event upsets and single-event latch-ups occurred in the test sample of two 64-Mbit DRAMs The DOS measured accumulated radiation dose at fifty-six locations in the body of the Tsubasa satellite Using the data obtained by these instruments single-event and total-dose effects in GTO during solar-activity maximum period especially their rapid changes due to solar flares and CMEs in the region from L 1 1 through L 11 is discussed in this paper

  19. A single exercise bout enhances the manufacture of viral-specific T-cells from healthy donors: implications for allogeneic adoptive transfer immunotherapy

    PubMed Central

    Spielmann, Guillaume; Bollard, Catherine M.; Kunz, Hawley; Hanley, Patrick J.; Simpson, Richard J.

    2016-01-01

    Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections remain a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). The adoptive transfer of donor-derived viral-specific cytotoxic T-cells (VSTs) is an effective treatment for controlling CMV and EBV infections after HSCT; however, new practical methods are required to augment the ex vivo manufacture of multi-VSTs from healthy donors. This study investigated the effects of a single exercise bout on the ex vivo manufacture of multi-VSTs. PBMCs isolated from healthy CMV/EBV seropositive participants before (PRE) and immediately after (POST) 30-minutes of cycling exercise were stimulated with CMV (pp65 and IE1) and EBV (LMP2A and BMLF1) peptides and expanded over 8 days. The number (fold difference from PRE) of T-cells specific for CMV pp65 (2.6), EBV LMP2A (2.5), and EBV BMLF1 (4.4) was greater among the VSTs expanded POST. VSTs expanded PRE and POST had similar phenotype characteristics and were equally capable of MHC-restricted killing of autologous target cells. We conclude that a single exercise bout enhances the manufacture of multi-VSTs from healthy donors without altering their phenotype or function and may serve as a simple and economical adjuvant to boost the production of multi-VSTs for allogeneic adoptive transfer immunotherapy. PMID:27181409

  20. Ultrasonic nebulization extraction-heating gas flow transfer-headspace single drop microextraction of essential oil from pericarp of Zanthoxylum bungeanum Maxim.

    PubMed

    Wei, Shigang; Zhang, Huihui; Wang, Yeqiang; Wang, Lu; Li, Xueyuan; Wang, Yinghua; Zhang, Hanqi; Xu, Xu; Shi, Yuhua

    2011-07-22

    The ultrasonic nebulization extraction-heating gas flow transfer coupled with headspace single drop microextraction (UNE-HGFT-HS-SDME) was developed for the extraction of essential oil from Zanthoxylum bungeanum Maxim. The gas chromatography-mass spectrometry was applied to the determination of the constituents in the essential oil. The contents of the constituents from essential oil obtained by the proposed method were found to be more similar to those obtained by hydro-distillation (HD) than those obtained by ultrasonic nebulization extraction coupled with headspace single drop microextraction (UNE-HS-SDME). The heating gas flow was firstly used in the analysis of the essential oil to transfer the analytes from the headspace to the solvent microdrop. The relative standard deviations for determining the five major constituents were in the range from 1.5 to 6.7%. The proposed method is a fast, sensitive, low cost and small sample consumption method for the determination of the volatile and semivolatile constituents in the plant materials.

  1. Single-stage Reconstruction of Elbow Flexion Associated with Massive Soft-Tissue Defect Using the Latissimus Dorsi Muscle Bipolar Rotational Transfer

    PubMed Central

    Cuéllar, Vanessa G.; Ghiassi, Alidad; Sharpe, Frances

    2016-01-01

    Introduction: In the upper extremity, the latissimus dorsi muscle can be used as an ipsilateral rotational muscle flap for soft-tissue coverage or functional reconstruction of arm and elbow. Patients who have both major soft-tissue loss and functional deficits can be successfully treated with a single-stage functional latissimus dorsi rotational muscle transfer that provides simultaneous soft-tissue coverage and functional reconstruction. Methods: Our data base was queried for all patients undergoing a rotational latissimus dorsi muscle transfer for simultaneous soft-tissue coverage and functional reconstruction of elbow flexion. Four patients were identified. A chart review documented the mechanism of injury, associated injuries, soft-tissue defect size, number of surgical procedures, length of follow-up, last elbow range of motion, and flexion strength. Results: Four patients with loss of elbow flexion due to traumatic loss of the anterior compartment muscles and the overlying soft tissue underwent simultaneous soft-tissue coverage and elbow flexorplasty using the ipsilateral latissimus dorsi as a bipolar muscle rotational tissue transfer. All flaps survived and had a recovery of Medical Research Council Grade 4/5 elbow flexion strength. No additional procedures were required for elbow flexion. The surgical technique is described and supplemented with surgical technique video and patient outcome. Conclusions: This patient series augments the data provided in other series supporting the safety and efficacy of this procedure which provides both soft-tissue coverage and functional restoration of elbow flexion as a single-stage procedure in the setting of massive traumatic soft-tissue loss of the arm. PMID:27757363

  2. Single-molecule spectroscopy and femtosecond transient absorption studies on the excitation energy transfer process in ApcE(1-240) dimers.

    PubMed

    Long, Saran; Zhou, Meng; Tang, Kun; Zeng, Xiao-Li; Niu, Yingli; Guo, Qianjin; Zhao, Kai-Hong; Xia, Andong

    2015-05-28

    ApcE(1-240) dimers with one intrinsic phycocyanobilin (PCB) chromophore in each monomer that is truncated from the core-membrane linker (ApcE) of phycobilisomes (PBS) in Nostoc sp. PCC 7120 show a sharp and significantly red-shifted absorption. Two explanations either conformation-dependent Förster resonance energy transfer (FRET) or the strong exciton coupling limit have been proposed for red-shifted absorption. This is a classic example of the special pair in the photosynthetic light harvesting proteins, but the mechanism of this interaction is still a matter of intense debate. We report the studies using single-molecule and transient absorption spectra on the interaction in the special pair of ApcE dimers. Our results demonstrate the presence of conformation-dependent FRET between the two PCB chromophores in ApcE dimers. The broad distributions of fluorescence intensities, lifetimes and polarization difference from single-molecule measurements reveal the heterogeneity of local protein-pigment environments in ApcE dimers, where the same molecular structures but different protein environments are the main reason for the two PCB chromophores with different spectral properties. The excitation energy transfer rate between the donor and the acceptor about (110 ps)(-1) is determined from transient absorption measurements. The red-shifted absorption in ApcE dimers could result from more extending conformation, which shows another type of absorption redshift that does not depend on strong exciton coupling. The results here stress the importance of conformation-controlled spectral properties of the chemically identical chromophores, which could be a general feature to control energy/electron transfer, widely existing in the light harvesting complexes.

  3. TallyHO obese female mice experience poor reproductive outcomes and abnormal blastocyst metabolism that is reversed by metformin.

    PubMed

    Louden, Erica D; Luzzo, Kerri M; Jimenez, Patricia T; Chi, Tiffany; Chi, Maggie; Moley, Kelle H

    2014-12-01

    Obese women experience worse reproductive outcomes than normal weight women, specifically infertility, pregnancy loss, fetal malformations and developmental delay of offspring. The aim of the present study was to use a genetic mouse model of obesity to recapitulate the human reproductive phenotype and further examine potential mechanisms and therapies. New inbred, polygenic Type 2 diabetic TallyHO mice and age-matched control C57BL/6 mice were superovulated to obtain morula or blastocyst stage embryos that were cultured in human tubal fluid (HTF) medium. Deoxyglucose uptake was determined for individual insulin-stimulated blastocysts. Apoptosis was detected by confocal microscopy using the terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labelling (TUNEL) assay and Topro-3 nuclear dye. Embryos were scored for TUNEL-positive as a percentage of total nuclei. AMP-activated protein kinase (AMPK) activation, tumour necrosis factor (TNF)-α expression and adiponectin expression were analysed by western immunoblot and confocal immunofluorescent microscopy. Lipid accumulation was assayed by BODIPY. Comparisons were made between TallyHO morulae cultured to blastocyst embryos in either HTF medium or HTF medium with 25 μg mL(-1) metformin. TallyHO mice developed whole body abnormal insulin tolerance, had decreased litter sizes and increased non-esterified fatty acid levels. Blastocysts from TallyHO mice exhibited increased apoptosis, decreased insulin sensitivity and decreased AMPK. A possible cause for the insulin