Heterometal Dopant Changes the Mechanism of Proton-Coupled Electron Transfer at the Polyoxovanadate-Alkoxide Surface.

The transfer of two H-atom equivalents to the titanium-doped polyoxovanadate-alkoxide, [TiV5O6(OCH3)13], results in the formation of a V(III)-OH2 site at the surface of the assembly. Incorporation of the group (IV) metal ion results in a weakening of the O-H bonds of [TiV5O5(OH2)(OCH3)13] in comparison to its homometallic congener, [V6O6(OH2)(OCH3)12], resembling more closely the thermodynamics reported for the one-electron reduced derivative, [V6O6(OH2)(OCH3)12]1-. An analysis of early time points of the reaction of [TiV5O6(OCH3)13] and 5,10-dihydrophenazine reveals the formation of an oxidized substrate, suggesting that proton-coupled electron transfer proceeds via initial electron transfer from substrate to cluster prior to proton transfer. These results demonstrate the profound influence of heterometal dopants on the mechanism of PCET with respect to the surface of the assembly.

Season at the time of oocyte collection and frozen embryo transfer outcomes.

STUDY QUESTION: Does the meteorological season at the time of oocyte retrieval affect live birth rates in subsequent frozen embryo transfers? SUMMARY ANSWER: Frozen embryo transfers resulting from oocytes retrieved in summer have 30% increased odds of live birth compared to frozen embryo transfers resulting from oocytes retrieved in autumn, regardless of the season at the time of embryo transfer. WHAT IS KNOWN ALREADY: Season at the time of frozen embryo transfer does not appear to be associated with live birth rate. One study in the northern hemisphere found increased odds of live birth with frozen embryo transfer resulting from oocytes collected in summer when compared to those collected in winter. STUDY DESIGN, SIZE, DURATION: Retrospective cohort study including all frozen embryo transfers performed by a single clinic over eight years, from January 2013 to December 2021. There were 3659 frozen embryo transfers with embryos generated from 2155 IVF cycles in 1835 patients. Outcome data were missing for two embryo transfers, which were excluded from analysis. Outcomes were analysed by the season, temperatures, and measured duration of sunshine at the time of oocyte collection and at the time of frozen embryo transfer. PARTICIPANTS/MATERIALS, SETTING, METHODS: There were no significant differences between patients with oocyte collection or embryo transfers in different seasons. Meteorological conditions on the day of oocyte collection and the day of frozen embryo transfer, and in the preceding 14- and 28-day periods, were collected including mean, minimum, and maximum temperatures, and recorded duration of sunshine hours. Clinical and embryological outcomes were analysed for their association with seasons, temperatures, and duration of sunshine with correction for repeated cycles per participant, age at the time of oocyte retrieval, and quadratic age. MAIN RESULTS AND THE ROLE OF CHANCE: Compared to frozen embryo transfers with oocyte retrieval dates in autumn, transfers with oocyte retrieval dates in summer had 30% increased odds of live birth (odds ratio (OR): 1.30, 95% CI: 1.04-1.62) which remained consistent after adjustment for season at the time of embryo transfer. A high duration of sunshine hours (in the top tertile) on the day of oocyte retrieval was associated with a 28% increase in odds of live birth compared to duration of sunshine hours in the lowest tertile (OR 1.28, 95% CI: 1.06-1.53). Temperature on the day of oocyte retrieval did not independently affect the odds of live birth. The odds of live birth were decreased by 18% when the minimum temperature on the day of embryo transfer was high, compared with low (OR: 0.82, 95% CI: 0.69-0.99), which was consistent after correction for the conditions at the time of oocyte retrieval. LIMITATIONS, REASONS FOR CAUTION: This was a retrospective cohort study, however, all patients during the study period were included and data was missing for only two patients. Given the retrospective nature, causation is not proven and there are other factors that may affect live birth rates and for which we did not have data and were unable to adjust, including pollutants and behavioural factors. We were also not able to stratify results based on specific patient populations (such as poor- or hyper-responders) nor report the cumulative live birth rate per commenced cycle. WIDER IMPLICATIONS OF THE FINDINGS: These findings may be particularly relevant for patients planning oocyte or embryo cryopreservation. Given the increasing utilization of cryopreservation, identification of factors that influence outcomes in subsequent frozen embryo transfers has implications for future therapeutic and management options. Further studies to clarify the physiology underlying the influence of sunshine hours or season on subsequent frozen embryo transfer outcomes are required, including identification of specific populations that may benefit from these factors. STUDY FUNDING/COMPETING INTERESTS: No funding was provided for this study. S.L. has received educational travel assistance from Besins, Merck and Organon outside the submitted work. R.H. is National Medical Director of City Fertility and Medical Director of Fertility Specialists of Western Australia, has received honoraria from MSD, Merck Serono, Origio and Ferring outside the submitted work, and has equity interests in CHA SMG. C.R., M.W., and E.N. declare that they have no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Precision Medicine Approach for Cardiometabolic Risk Factors in Therapeutic Apheresis.

Lipoprotein apheresis (LA) is currently the most powerful intervention possible to reach a maximal reduction of lipids in patients with familial hypercholesterolemia and lipoprotein(a) hyperlipidemia. Although LA is an invasive method, it has few side effects and the best results in preventing further major cardiovascular events. It has been suggested that the highly significant reduction of cardiovascular complications in patients with severe lipid disorders achieved by LA is mediated not only by the potent reduction of lipid levels but also by the removal of other proinflammatory and proatherogenic factors. Here we performed a comprehensive proteomic analysis of patients on LA treatment using intra-individually a set of differently sized apheresis filters with the INUSpheresis system. This study revealed that proteomic analysis correlates well with routine clinical chemistry in these patients. The method is eminently suited to discover new biomarkers and risk factors for cardiovascular disease in these patients. Different filters achieve reduction and removal of proatherogenic proteins in different quantities. This includes not only apolipoproteins, C-reactive protein, fibrinogen, and plasminogen but also proteins like complement factor B (CFAB), protein AMBP, afamin, and the low affinity immunoglobulin gamma Fc region receptor III-A (FcγRIIIa) among others that have been described as atherosclerosis and metabolic vascular diseases promoting factors. We therefore conclude that future trials should be designed to develop an individualized therapy approach for patients on LA based on their metabolic and vascular risk profile. Furthermore, the power of such cascade filter treatment protocols may improve the prevention of cardiometabolic disease and its complications.

Different growth regimes in InP nanowire growth mediated by Ag nanoparticles.

We report on the existence of two different regimes in one-step Ag-seeded InP nanowire growth. The vapor-liquid-solid-mechanism is present at larger In precursor flows and temperatures, ∼500 °C, yielding high aspect ratio and pure wurtzite InP nanowires with a semi-spherical metal particle at the thin apex. Periodic diameter oscillations can be achieved under extreme In supersaturations at this temperature range, showing the presence of a liquid catalyst. However, under lower temperatures and In precursor flows, large diameter InP nanowires with mixed wurtzite/zincblende segments are obtained, similarly to In-assisted growth. Chemical composition analysis suggest that In-rich droplet formation is catalyzed at the substrate surface via Ag nanoparticles; this process might be facilitated by the sulfur contamination detected in these nanoparticles. Furthermore, part of the original Ag nanoparticle remains solid and is embedded inside the actual catalyst, providing an in situ method to switch growth mechanisms upon changing In precursor flow. Nevertheless, our Ag-seeded InP nanowires exhibit overall optical emission spectra consistent with the observed structural properties and similar to Au-catalyzed InP nanowires. We thus show that Ag nanoparticles may be a suitable replacement for Au in InP nanowire growth.

High Concentrations of Measles Neutralizing Antibodies and High-Avidity Measles IgG Accurately Identify Measles Reinfection Cases.

In the United States, approximately 9% of the measles cases reported from 2012 to 2014 occurred in vaccinated individuals. Laboratory confirmation of measles in vaccinated individuals is challenging since IgM assays can give inconclusive results. Although a positive reverse transcription (RT)-PCR assay result from an appropriately timed specimen can provide confirmation, negative results may not rule out a highly suspicious case. Detection of high-avidity measles IgG in serum samples provides laboratory evidence of a past immunologic response to measles from natural infection or immunization. High concentrations of measles neutralizing antibody have been observed by plaque reduction neutralization (PRN) assays among confirmed measles cases with high-avidity IgG, referred to here as reinfection cases (RICs). In this study, we evaluated the utility of measuring levels of measles neutralizing antibody to distinguish RICs from noncases by receiver operating characteristic curve analysis. Single and paired serum samples with high-avidity measles IgG from suspected measles cases submitted to the CDC for routine surveillance were used for the analysis. The RICs were confirmed by a 4-fold rise in PRN titer or by RT-quantitative PCR (RT-qPCR) assay, while the noncases were negative by both assays. Discrimination accuracy was high with serum samples collected ≥3 days after rash onset (area under the curve, 0.953; 95% confidence interval [CI], 0.854 to 0.993). Measles neutralizing antibody concentrations of ≥40,000 mIU/ml identified RICs with 90% sensitivity (95% CI, 74 to 98%) and 100% specificity (95% CI, 82 to 100%). Therefore, when serological or RT-qPCR results are unavailable or inconclusive, suspected measles cases with high-avidity measles IgG can be confirmed as RICs by measles neutralizing antibody concentrations of ≥40,000 mIU/ml.

Atomic-resolved depth profile of strain and cation intermixing around LaAlO3/SrTiO3 interfaces.

Novel behavior has been observed at the interface of LaAlO3/SrTiO3 heterostructures such as two dimensional metallic conductivity, magnetic scattering and superconductivity. However, both the origins and quantification of such behavior have been complicated due to an interplay of mechanical, chemical and electronic factors. Here chemical and strain profiles near the interface of LaAlO3/SrTiO3 heterostructures are correlated. Conductive and insulating samples have been processed, with thicknesses respectively above and below the commonly admitted conductivity threshold. The intermixing and structural distortions within the crystal lattice have been quantitatively measured near the interface with a depth resolution of unit cell size. A strong link between intermixing and structural distortions at such interfaces is highlighted: intermixing was more pronounced in the hetero-couple with conductive interface, whereas in-plane compressive strains extended deeper within the substrate of the hetero-couple with the insulating interface. This allows a better understanding of the interface local mechanisms leading to the conductivity.

Testicular function in a birth cohort of young men.

STUDY QUESTION: By investigating a birth cohort with a high ongoing participation rate to derive an unbiased population, what are the parameters and influences upon testicular function for a population not selected with regard to fertility? SUMMARY ANSWER: While varicocele, cryptorchidism and obesity may impact on human testicular function, most common drug exposures and the presence of epididymal cysts appear to have no or minimal adverse impact. WHAT IS KNOWN ALREADY: The majority of previous attempts to develop valid reference populations for spermatogenesis have relied on potentially biased sources such as recruits from infertility clinics, self-selected volunteer sperm donors for research or artificial insemination or once-fertile men seeking vasectomy. It is well known that studies requiring semen analysis have low recruitment rates which consequently question their validity. However, there has been some concern that a surprisingly high proportion of young men may have semen variables that do not meet all the WHO reference range criteria for fertile men, with some studies reporting that up to one half of participants have not meet the reference range for fertile men. Reported median sperm concentrations have ranged from 40 to 60 million sperm/ml. STUDY DESIGN, SIZE AND DURATION: The Western Australian Pregnancy Cohort (Raine) was established in 1989. At 20-22 years of age, members of the cohort were contacted to attend for a general follow-up, with 753 participating out of the 913 contactable men. Of these, 423 men (56% of participants in the 20-22 years cohort study, 46% of contactable men) participated in a testicular function study. Of the 423 men, 404 had a testicular ultrasound, 365 provided at least one semen sample, 287 provided a second semen sample and 384 provided a blood sample. PARTICIPANTS/MATERIALS, SETTING, METHODS: Testicular ultrasound examinations were performed at King Edward Memorial Hospital, Subiaco, Perth, for testicular volume and presence of epididymal cysts and varicoceles. Semen samples were provided and analysed by standard semen assessment and a sperm chromatin structural assay (SCSA) at Fertility Specialists of Western Australia, Claremont, Perth. Serum blood samples were provided at the University of Western Australia, Crawley, Perth and were analysed for serum luteinizing hormone (LH), follicular stimulating hormone (FSH), inhibin B, testosterone, dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA), estradiol, estrone and the primary metabolites of DHT: 5α-androstane-3α,17ß-diol (3α-diol) and 5-α androstane-3-ß-17-beta-diol (3ß-diol). Serum steroids were measured by liquid chromatography, mass spectrometry and LH, FSH and inhibin B were measured by ELISA assays. MAIN RESULTS AND THE ROLE OF CHANCE: Cryptorchidism was associated with a significant reduction in testicular (P = 0.047) and semen (P = 0.027) volume, sperm concentration (P = 0.007) and sperm output (P = 0.003). Varicocele was associated with smaller testis volume (P < 0.001), lower sperm concentration (P = 0.012) and total sperm output (P = 0.030) and lower serum inhibin B levels (P = 0.046). Smoking, alcohol intake, herniorrhaphy, an epididymal cyst, medication and illicit drugs were not associated with any significant semen variables, testicular volume or circulating reproductive hormones. BMI had a significantly negative correlation with semen volume (r = -0.12, P = 0.048), sperm output (r = -0.13, P = 0.02), serum LH (r = -0.16, P = 0.002), inhibin B (r = -0.16, P < 0.001), testosterone (r = -0.23, P < 0.001) and DHT (r = -0.22, P < 0.001) and a positive correlation with 3αD (r = 0.13, P = 0.041) and DHEA (r = 0.11, P = 0.03). Second semen samples compared with the first semen samples in the 287 participants who provided two samples, with no significant bias by Bland-Altman analysis. Testis volume was significantly correlated positively with sperm concentration (r = 0.25, P < 0.001) and sperm output (r = 0.29, P < 0.001) and inhibin B (r = 0.42, P < 0.001), and negatively correlated with serum LH (r = -0.24, P < 0.001) and FSH (r = -0.32, P < 0.001). SCSA was inversely correlated with sperm motility (r = -0.20, P < 0.001) and morphology (r = -0.16, P = 0.005). WHO semen reference criteria were all met by only 52 men (14.4%). Some criteria were not met at first analysis in 15-20% of men, including semen volume (<1.5 ml, 14.8%), total sperm output (<39 million, 18.9%), sperm concentration (<15 million/ml, 17.5%), progressive motility (<32%, 14.4%) and morphologically normal sperm (<4%, 26.4%), while all five WHO criteria were not met in four participants (1.1%). LIMITATIONS AND REASONS FOR CAUTION: This was a large cohort study; however, potential for recruitment bias still exists. Men who did not participate in the testicular evaluation study (n = 282) did not differ from those who did (n = 423) with regard to age, weight, BMI, smoking or circulating reproductive hormones (LH, FSH, inhibin B, T, DHT, E2, E1, DHEA, 3α-diol, 3ß-diol), but were significantly shorter (178 versus 180 cm, P = 0.008) and had lower alcohol consumption (P = 0.019) than those who did participate. WIDER IMPLICATIONS OF THE FINDINGS: This study demonstrated the feasibility of establishing a birth cohort to provide a relatively unbiased insight into population-representative sperm output and function and of investigating its determinants from common exposures. While varicocele, cryptorchidism and obesity may impact on human testicular function, most common drug exposures and the presence of epididymal cysts appear to have little adverse impact, and this study suggests that discrepancies from the WHO reference ranges are expected, due to its derivation from non-population-representative fertile populations.

In vitro maturation is associated with increased early embryo arrest without impairing morphokinetic development of useable embryos progressing to blastocysts.

STUDY QUESTIONS: Does polycystic ovarian syndrome (PCOS) or in vitro maturation (IVM) treatment affect embryo development events and morphokinetic parameters after time-lapse incubation? SUMMARY ANSWER: There was an increase in some abnormal phenotypic events in PCOS-IVM embryos as well as an increase in early arrest of PCOS-IVM and PCOS-ICSI embryos; however, IVM treatment or PCOS status did not alter morphokinetic development of embryos suitable for transfer of vitrification. WHAT IS KNOWN ALREADY: IVM has been less successful than standard IVF in terms of clinical pregnancy, implantation and live birth rates. There is currently no information available about the development of IVM embryos according to time-lapse analysis. STUDY DESIGN, SIZE AND DURATION: This article represents a prospective case-control study. The study involved 93 participants who underwent 93 treatment cycles. Cycles were completed between January 2013 and July 2014. PARTICIPANTS/MATERIALS, SETTING AND METHODS: Participants were recruited for the study at Fertility Specialists of WA and Fertility Specialists South, Perth, Western Australia. Of the PCOS diagnosed patients, 32 underwent IVM treatment (PCOS-IVM) and 23 had standard ICSI treatment (PCOS-ICSI). There were 38 patients without PCOS who underwent standard ICSI treatment comprising the control group (control-ICSI). MAIN RESULTS AND THE ROLE OF CHANCE: The PCOS-IVM group showed significantly more embryos with multinucleated two cells (P = 0.041), multinucleated four cells (P = 0.001) and uneven two cells (P = 0.033) compared with the control-ICSI group, but not the PCOS-ICSI group. There were no significant differences in the rates of any abnormal events between the PCOS-ICSI and control-ICSI groups. Embryo arrest between Days 2 and 3 was higher in the PCOS-IVM and PCOS-ICSI groups compared with the control-ICSI group (P < 0.001 and P = 0.001). Embryo arrest from Days 3 to 4 was higher in the PCOS-IVM group compared with both the PCOS-ICSI and control-ICSI groups (P < 0.001). There were no differences in embryo arrest rates across all three groups at the compaction or blastulation stages. Cumulative rates of embryo arrest, from the time to second polar body extrusion (tPB2) to the time to formation of a blastocyst (tB), result in a decreased proportion of useable PCOS-IVM blastocysts compared with the other two treatment groups; however, of the embryos remaining, there was no significant difference in morphokinetic development between the three groups. LIMITATIONS AND REASONS FOR CAUTION: This was a small study using time-lapse analysis of embryo development as the primary end-point. Larger, randomized, clinical trials are required to clarify the implications of time-lapse incubation of IVM embryos and the effects on implantation and ongoing pregnancy. WIDER IMPLICATIONS OF THE FINDINGS: This is the first study to compare the time-lapse analysis of IVM with standard ICSI for patients with and without PCOS. This allows for a more detailed and specific timeline of events from embryos generated using this approach for patients diagnosed with PCOS and shows that embryos generated from IVM have an increased rate of early embryo arrest, however; morphokinetic development is not impaired in embryos that progress to the useable blastocyst stage. STUDY FUNDING/COMPETING INTERESTS: The study was supported by the Women's and Infant's Research Foundation of Western Australia. R.H. is the Medical Director of Fertility Specialists of Western Australia and a shareholder in Western IVF. He has received educational sponsorship from MSD, Merck-Serono and Ferring Pharmaceuticals. The other authors have no competing interests.

In vitro maturation as an alternative to standard in vitro fertilization for patients diagnosed with polycystic ovaries: a comparative analysis of fresh, frozen and cumulative cycle outcomes.

STUDY QUESTION: Is in vitro maturation (IVM) as successful as standard in vitro fertilization (IVF) for the treatment of patients with polycystic ovaries (PCO) in terms of fresh, frozen and cumulative pregnancy outcomes? SUMMARY ANSWER: There was no difference in clinical pregnancy rates in fresh or frozen embryo transfer (FET) cycles between the two treatment groups however, the IVM group showed a lower clinical pregnancy rate cumulatively. There was significantly fewer live births resulting from IVM treatment for both fresh and cumulative cycle outcomes however, there was no difference in live birth rates resulting from FETs between IVM and IVF treatment. WHAT IS KNOWN ALREADY: IVM is well recognized as the only treatment option to eliminate completely the incidence of ovarian hyperstimulation syndrome. However, historically IVM has been less successful than standard IVF in terms of clinical pregnancy, implantation and live birth rates. STUDY DESIGN, SIZE, AND DURATION: This paper represents a retrospective case-control study. The study involved 121 participants who underwent 178 treatment cycles. Cycles were completed between March 2007 and December 2012. All fresh cycles and subsequent FET cycles were included in the analysis to calculate cumulative outcomes. PARTICIPANTS/MATERIALS, SETTING, AND METHODS: All participants were prospectively diagnosed with PCO morphology or polycystic ovarian syndrome (PCOS) and underwent either IVM or standard IVF treatment. Their treatment outcomes were analysed with regard to embryological data, and the rate of biochemical pregnancy, clinical pregnancy and live birth, in addition maternal and neonatal outcomes were assessed. Fifty-six patients underwent 80 cycles of IVM treatment and 65 patients underwent 98 cycles of standard IVF treatment. MAIN RESULTS AND THE ROLE OF CHANCE: For fresh cycles, the differences in the biochemical pregnancy, clinical pregnancy or miscarriage rates between the two treatment groups were not statistically significant. The IVM group showed significantly lower live birth rates in fresh cycles in comparison to standard IVF treatment (18.8 versus 31.0%, P = 0.021). For frozen embryo transfer (FET) cycles the differences in biochemical pregnancy, clinical pregnancy, live birth or miscarriage rates between the two treatments groups were not statistically significant. The cumulative biochemical pregnancy (67.5 versus 83.7%, P = 0.018), clinical pregnancy (51.3 versus 65.3%, P = 0.021) and live birth rates (41.3 versus 55.1%, P = 0.005) were significantly lower in the IVM group in comparison to the standard IVF treatment group. There was no overall difference in the cumulative miscarriage rates between the two treatment groups. There was no difference between treatment methods with regard to the neonatal outcomes, and the IVM group had a significantly lower rate of ovarian hyperstimulation syndrome (0 versus 7.1%, P < 0.001). LIMITATIONS, REASONS FOR CAUTION: This was an observational study and further randomized clinical trials are required to clarify the difference in outcomes between standard IVF and IVM for patients with PCO/PCOS. WIDER IMPLICATIONS OF THE FINDINGS: This is the first study to compare IVM with standard IVF in PCO/PCOS patients using blastocyst development and single embryo transfer. Furthermore, it is the first study to show the results of fresh, frozen and cumulative treatment cycle outcomes between the two groups. Our results show similar success rates to those reported from other groups, particularly in relation to the incidence of miscarriage in fresh IVM cycles and improved success from FET cycles. Maternal and neonatal outcomes are consistent with the limited literature available. STUDY FUNDING/COMPETING INTERESTS: The study was supported by the Women's and Infant's Research Foundation of Western Australia. Professor Hart is Medical Director of Fertility Specialists of Western Australia (FSWA) and a shareholder Western IVF. He has received educational sponsorship from MSD, Merck-Serono and Ferring Pharmaceuticals. T.H. is a consultant with FSWA and a shareholder in Western IVF. She has received educational sponsorship from MSD, Merck-Serono and Ferring Pharmaceuticals. The other authors have no competing interests.

IVF versus ICSI for the fertilization of in-vitro matured human oocytes.

Traditional dogma suggests that intracytoplasmic sperm injection (ICSI) should be performed to ensure successful oocyte fertilization in an in-vitro maturation (IVM) cycle. This study postulated that there would be no difference in the fertilization rate when ICSI was compared with IVF. This hypothesis was tested in a randomized trial of IVF versus ICSI in IVM. A total of 150 immature oocytes were collected in eight cycles of IVM for patients diagnosed with polycystic ovarian syndrome (PCOS). Patients were primed with minimal FSH before transvaginal oocyte aspiration. Sibling oocytes were inseminated by 50% IVF and 50% ICSI. There was no significant difference in fertilization, useable or total blastocyst development between the two insemination technique groups. Clinical pregnancy results for combined fresh and cryopreserved transfers were identical between the two insemination techniques with a total of two fresh and five cryopreserved IVF-inseminated embryos resulting in three clinical pregnancies (42.9%) and five fresh and two cryopreserved ICSI-derived embryos resulting in three clinical pregnancies (42.9%). This research has shown IVF to be a legitimate fertilization technique for IVM oocytes in PCOS patients and provides a greater awareness of the use of a fertilization method previously not utilized with IVM. In-vitro maturation (IVM) is an alternative treatment method to traditional IVF. Due to the minimal use of stimulating hormones in this treatment, IVM has a lower risk of ovarian hyperstimulation syndrome, it can be used for fertility preservation in cancer patients and it is more cost conservative. Early research into the effects of IVM showed a hardening effect on the membrane surrounding the egg (the zona pellucida). It was initially believed that, to overcome this hardening in order to allow the egg to be fertilized, spermatozoa would need to be injected into the egg using intracytoplasmic sperm injection. Due to recent advances in hormonal stimulation protocols (FSH priming) and culture conditions, we postulated that, for patients suffering from polycystic ovarian syndrome (PCOS), fertilization, embryo development and clinical pregnancy would not be superior in the injected oocytes compared with those inseminated by IVF. We found that by using the two insemination techniques on sibling oocytes from eight PCOS patients, there was no significant difference in fertilization, useable or total blastocyst development (day 5 or 6 embryos) and that clinical pregnancy results were identical. This research provides a greater awareness of a fertilization technique which is not normally utilized for IVM treatment, providing a less invasive, more cost-effective approach for the patient.

Mapping titanium and tin oxide phases using EELS: an application of independent component analysis.

We study materials that present challenges for conventional elemental mapping techniques and can in some cases be treated successfully using independent component analysis (ICA). In this case the material in question is obtained from a TiO2-SiO2 solid solution that is spinodally decomposed into TiO2 rich-SnO2 rich multilayers. Conventional elemental mapping is difficult because the edges most easily mapped for these elements (Ti-L, Sn-M and O-K) all have onsets within the same 80 eV range. ICA is used to separate entire spectral signals corresponding to particular material phases or molecular units rather than particular elements and is thus able to distinguish between TiO2 and SnO2. We show that quantification of oxide species can be performed by different methods that require extra assumptions, but nevertheless should be feasible in many cases.

Blocking of indium incorporation by antimony in III-V-Sb nanostructures.

The addition of antimony to III-V nanostructures is expected to give greater freedom in bandgap engineering for device applications. One of the main challenges to overcome is the effect of indium and antimony surface segregation. Using several very high resolution analysis techniques we clearly demonstrate blocking of indium incorporation by antimony. Furthermore, indium incorporation resumes when the antimony concentration drops below a critical level. This leads to major differences between nominal and actual structures.

Multi-dimensional and multi-signal approaches in scanning transmission electron microscopes.

Developments in instrumentation are essential to open new fields of science. This clearly applies to electron microscopy, where recent progress in all hardware components and in digitally assisted data acquisition and processing has radically extended the domains of application. The demonstrated breakthroughs in electron optics, such as the successful design and practical realization and the use of correctors, filters and monochromators, and the permanent progress in detector efficiency have pushed forward the performance limits, in terms of spatial resolution in imaging, as well as for energy resolution in electron energy-loss spectroscopy (EELS) and for sensitivity to the identification of single atoms. As a consequence, the objects of the nanoworld, of natural or artificial origin, can now be explored at the ultimate atomic level. The improved energy resolution in EELS, which now encompasses the near-IR/visible/UV spectral domain, also broadens the range of available information, thus providing a powerful tool for the development of nanometre-level photonics. Furthermore, spherical aberration correctors offer an enlarged gap in the objective lens to accommodate nanolaboratory-type devices, while maintaining angström-level resolution for general characterization of the nano-object under study.

Immunity of coated self-ordered silver nanocrystals: a new intrinsic property due to the nanocrystal ordering.

New materials made of two- and three-dimensional superlattices of nanoparticles exhibit unique collective properties arising from the ordering of the nanoparticles. Here, dodecanethiol-coated silver nanocrystals self-assembled in 2D were subjected to oxygen plasma using the reactive ion etching process. The careful investigation by transmission electronic microscopy (TEM) of the same areas before and after exposure allows one to distinguish two behaviors under plasma treatment, which are determined by the level of ordering of the 2D organizations. Higher ordered self-assemblies remain unchanged, while less ordered organizations coalesce into larger nanocrystals with spheroidal shapes that could be single crystals. Electron energy-loss spectroscopy (EELS) measurements show that there is no oxidation of the silver either on the large coalesced nanocrystals or on the stable self-assemblies. A new intrinsic property, immunity of highly self-ordered nanocrystals provided by the ordering, is reported, and a mechanism of the coalescence is proposed.

Extending the analysis of EELS spectrum-imaging data, from elemental to bond mapping in complex nanostructures.

Multiple least squares fitting has been employed for long time in elemental electron energy-loss spectroscopy (EELS) analysis, in particular in biology, but with the hypothesis of a rather stable shape for the used core-loss signals. In the present case, we explore its use for identifying the variations in the edges' fine structures in complex boron nitride samples and in particular for mapping the bonding types of boron in such samples. Details about this improved procedure applied to data acquired in the spectrum-imaging mode are reported here.

2D self-organization of core/shell Co(hcp)/Co nanocrystals.

In this paper we report the preparation of ordered hexagonal 2D arrays of core/shell Cohcp/CoO nanocrystals. A full structural investigation has been carried out using high-resolution transmission electron microscopy, electron diffraction, and electron energy-loss spectroscopy.

Electrochemical and microstructural studies of tantalum and its oxide films for biomedical applications in endovascular surgery.

The most popular coronary stents are made of 316L stainless steel and self-expandable Nitinol. Nevertheless, Ta has already been used to make stents for endovascular surgery and may constitute a good alternative to the other materials because of its higher corrosion resistance and radio-opacity property, which may facilitate the follow-up of stent catheterization. The characterization of Ta and its natural passive oxide films has been performed in a 0.15 M NaCl solution (simulated body fluid - SBF) using anodic polarizations, electrochemical impedance spectroscopy and photoelectrochemical techniques. Changes in microstructure have been observed by atomic force microscopy (AFM). Polarization curves show the existence of a current density increase between 1.40 and 1.80 V. Bode complex plots show that some perturbation of the film occurred in this potential interval which may be associated with a decrease in polarization resistance, Rp, indicating that the film may be less resistant to corrosive attack. Mott-Schottky capacity measurements show that the density of donors, Nd, varies with polarization. The optical band gap, E(g), which is equal to 4.1 eV did not show variations in our experiments. The localized formation on the electrode surface, in the above potential interval of a Ta compound (possibly an oxide-hydroxide) was observed by AFM, and this may explain the appearance of the current density peak and capacity behavior at those potentials.