The Role of Momentum Partitioning in Covariance Ion Imaging Analysis.

We present results from a covariance ion imaging study, which employs extensive filtering, on the relationship between fragment momenta to gain deeper insight into photofragmentation dynamics. A new data analysis approach is introduced that considers the momentum partitioning between the fragments of the breakup of a molecular polycation to disentangle concurrent fragmentation channels, which yield the same ion species. We exploit this approach to examine the momentum exchange relationship between the products, which provides direct insight into the dynamics of molecular fragmentation. We apply these techniques to extensively characterize the dissociation of 1-iodopropane and 2-iodopropane dications prepared by site-selective ionization of the iodine atom using extreme ultraviolet intense femtosecond laser pulses with a photon energy of 95 eV. Our assignments are supported by classical simulations, using parameters largely obtained directly from the experimental data.

Exploring the ultrafast and isomer-dependent photodissociation of iodothiophenes via site-selective ionization.

C-I bond extension and fission following ultraviolet (UV, 262 nm) photoexcitation of 2- and 3-iodothiophene is studied using ultrafast time-resolved extreme ultraviolet (XUV) ionization in conjunction with velocity map ion imaging. The photoexcited molecules and eventual I atom products are probed by site-selective ionization at the I 4d edge using intense XUV pulses, which induce multiple charges initially localized to the iodine atom. At C-I separations below the critical distance for charge transfer (CT), charge can redistribute around the molecule leading to Coulomb explosion and charged fragments with high kinetic energy. At greater C-I separations, beyond the critical distance, CT is no longer possible and the measured kinetic energies of the charged iodine atoms report on the neutral dissociation process. The time and momentum resolved measurements allow determination of the timescales and the respective product momentum and kinetic energy distributions for both isomers, which are interpreted in terms of rival 'direct' and 'indirect' dissociation pathways. The measurements are compared with a classical over the barrier model, which reveals that the onset of the indirect dissociation process is delayed by ∼1 ps relative to the direct process. The kinetics of the two processes show no discernible difference between the two parent isomers, but the branching between the direct and indirect dissociation channels and the respective product momentum distributions show isomer dependencies. The greater relative yield of indirect dissociation products from 262 nm photolysis of 3-iodothiophene (cf. 2-iodothiophene) is attributed to the different partial cross-sections for (ring-centred) π∗ ← π and (C-I bond localized) σ∗ ← (n/π) excitation in the respective parent isomers.

Evaluation of Lipopolysaccharide and Interleukin-6 as Useful Screening Tool for Chronic Endometritis.

Universal diagnostic criteria for chronic endometritis (CE) have not been established due to differences in study design among researchers and a lack of typical clinical cases. Lipopolysaccharides (LPSs) have been reported to cause inflammation in the reproductive systems of several animals. This study aimed to elucidate the influence of LPS in the pathogenesis of CE in humans. We investigated whether LPS affected cytokine production and cell proliferation in the endometrium using in vivo and in vitro experiments. LPS concentrations were analyzed between control and CE patients using endometrial tissues. LPS administration stimulated the proliferation of EM-E6/E7 cells derived from human endometrial cells. High LPS concentrations were detected in CE patients. LPS concentration was found to correlate with IL-6 gene expression in the endometrium. Inflammation signaling evoked by LPS led to the onset of CE, since LPS stimulates inflammatory responses and cell cycles in the endometrium. We identified LPS and IL-6 as suitable candidate markers for the diagnosis of CE.

Chiroptical Performances in Self-Assembled Hierarchical Nanosegregated Chiral Intermediate Phases Composed of Two Different Achiral Bent-Core Molecules.

In this paper, chiral intermediate phases composed of two achiral molecules are fabricated by utilizing nanophase separation and molecular hierarchical self-organization. An achiral bent-core guest molecule, exhibiting a calamitic nematic and a dark conglomerate phase according to the temperature, is mixed with another achiral bent-core host molecule possessing a helical nanofilament to separate the phases between them. Two nanosegregated phases are identified, and considerable chiroptical changes, such as circular dichroism and circularly polarized luminescence, are detected at the transition temperatures between the different nanophase-separated states. The nanosegregated chiral phase-wherein the helical nanofilament and dark conglomerate phases are phase-separated-exhibits the highest chiroptical intensities. The luminescence dissymmetry factor, |glum|, in this phase is amplified by an order of magnitude compared with that of another nanosegregated phase, wherein the helical nanofilament and nematic phases are phase-separated.

The effect of the structure of a helical nanofilament of the B4 phase of bent-core liquid crystals on the nano-phase separation mixed with a rod-like cholesteric liquid crystal mixture.

We studied the structure of a helical nano-filament of the B4 phase in mixtures of a cholesteric liquid crystal mixture and a bent-core molecule using a resonant soft X-ray scattering (RSoXS) technique. In this system, nanophase separation occurs and it was already found that an unexpected new functional chiral smectic structure in the rod-like molecule rich region is constructed by the strong interaction between bent-core and rod-like molecules. In this paper, we focused on the structure of the helical filament in the bent-core liquid crystalline molecule rich region in this mixing system, and it was found that the pitch of the helical filament decreases and the coherence of the helical structure increases.

Disentangling sequential and concerted fragmentations of molecular polycations with covariant native frame analysis.

We present results from an experimental ion imaging study into the fragmentation dynamics of 1-iodopropane and 2-iodopropane following interaction with extreme ultraviolet intense femtosecond laser pulses with a photon energy of 95 eV. Using covariance imaging analysis, a range of observed fragmentation pathways of the resulting polycations can be isolated and interrogated in detail at relatively high ion count rates (∼12 ions shot-1). By incorporating the recently developed native frames analysis approach into the three-dimensional covariance imaging procedure, contributions from three-body concerted and sequential fragmentation mechanisms can be isolated. The angular distribution of the fragment ions is much more complex than in previously reported studies for triatomic polycations, and differs substantially between the two isomeric species. With support of simple simulations of the dissociation channels of interest, detailed physical insights into the fragmentation dynamics are obtained, including how the initial dissociation step in a sequential mechanism influences rovibrational dynamics in the metastable intermediate ion and how signatures of this nuclear motion manifest in the measured signals.

Specific chemical bond relaxation unraveled by analysis of shake-up satellites in the oxygen single site double core hole spectrum of CO2.

We recently developed [A. Ferté, et al., J. Phys. Chem. Lett., 2020, 11, 4359] a method to compute single site double core hole (ssDCH or K-2) spectra. We refer to that method as NOTA+CIPSI. In the present paper this method is applied to the O K-2 spectrum of the CO2 molecule, and we use this as an example to discuss in detail its convergence properties. Using this approach, theoretical spectra in excellent agreement with the experimental one are obtained. Thanks to a thorough interpretation of the shake-up states responsible for the main satellite peaks and through comparison with the O K-2 spectrum of CO, we can highlight the clear signature of the two non-equivalent carbon oxygen bonds in the oxygen ssDCH CO2 dication.

Multi-channel photodissociation and XUV-induced charge transfer dynamics in strong-field-ionized methyl iodide studied with time-resolved recoil-frame covariance imaging.

The photodissociation dynamics of strong-field ionized methyl iodide (CH3I) were probed using intense extreme ultraviolet (XUV) radiation produced by the SPring-8 Angstrom Compact free electron LAser (SACLA). Strong-field ionization and subsequent fragmentation of CH3I was initiated by an intense femtosecond infrared (IR) pulse. The ensuing fragmentation and charge transfer processes following multiple ionization by the XUV pulse at a range of pump-probe delays were followed in a multi-mass ion velocity-map imaging (VMI) experiment. Simultaneous imaging of a wide range of resultant ions allowed for additional insight into the complex dynamics by elucidating correlations between the momenta of different fragment ions using time-resolved recoil-frame covariance imaging analysis. The comprehensive picture of the photodynamics that can be extracted provides promising evidence that the techniques described here could be applied to study ultrafast photochemistry in a range of molecular systems at high count rates using state-of-the-art advanced light sources.

Quantitative evaluation of intercellular local deformation of human oocytes during Piezo-assisted intracytoplasmic sperm injection using video-based motion analysis.

OBJECTIVE: To evaluate the relationship between the quantitative properties of local deformation of the ooplasm during Piezo-assisted intracytoplasmic sperm injection (Piezo-ICSI) and oocyte developmental fate after Piezo-ICSI. DESIGN: Video-based motion analysis and case-control study. SETTING: Private fertility center. PATIENT(S): A total of 99 couples assigned to the standard Piezo-ICSI program. INTERVENTION(S): Video recordings of the sperm injection process during Piezo-ICSI. MAIN OUTCOME MEASURE(S): Quantitative deformation properties consisting of the orientation of deformation perpendicular (Perp) or parallel (Para) to the oolemma and the mechanical response of the ooplasm (elongation, contraction, and total): Perp-elongation, Perp-contraction, Perp-total, Para-elongation, Perp-contraction, and Para-total. RESULT(S): The deformation parameters were compared among different angular ranges of 30°-60°, 60°-90°, 90°-120°, and 120°-150° (defined as 0° at the 3 o'clock puncture site). The Perp-total value at 30°-60° was significantly greater than that at the other angles (130.2 vs. 57.7-85.5, respectively) primarily due to substantially greater Perp-elongation values. The Para-total value at 30°-60° was significantly greater than that at the other angles (20.1 vs. 6.7-10.3, respectively) primarily due to substantially smaller Para-contraction values. The deformation parameters of the ooplasm adjacent to the first polar body were also compared among different developmental fates (fertilization failure, cleavage arrest, and blastocyst development). The Perp-total value of oocytes derived from blastocyst formation was significantly smaller than those derived from other developmental fates (58.1 vs. 70.0-87.3, respectively). CONCLUSION(S): The Piezo-ICSI process induced deformation with various mechanical behaviors in different regions within a single oocyte. Furthermore, the exposure of the ooplasm adjacent to the first polar body to excessive deformation was found to be a possible trigger for adverse fertilization and embryo development after Piezo-ICSI.

Photoelectron based soft x-ray detector for removing high order x rays.

Soft x-ray absorption spectroscopy (XAS) in the low energy region below 200 eV is important to investigate chemical and biological phenomena under an atmospheric condition since it covers K-edges of Li and B and L-edges of Si, P, S, and Cl. Monochromatic soft x rays usually include not only first order x rays but also high order x rays due to the high order diffraction of a plane grating monochromator. It is difficult to measure XAS in the low energy region under an atmospheric helium condition since the transmitted soft x rays mostly consist of the high order x rays due to the low transmission of the first order x rays. In this study, we have developed a photoelectron based soft x-ray (PBSX) detector, where the Au 4f photoelectrons emitted by the first order x rays are separated from those by the high order x rays using a difference in kinetic energies of photoelectrons. By using the PBSX detector, we have successfully obtained Si L-edge XAS spectra of the SiC and polymer/SiC films that mainly include the first order x rays by removing the major contributions of the second order x rays at the C K-edge and the fifth order x rays at the O K-edge. In the future, several physical, chemical, and biological phenomena in solution will be investigated by XAS in the low energy region with the PBSX detector.

Advanced Computation Method for Double Core Hole Spectra: Insight into the Nature of Intense Shake-up Satellites.

Double core hole spectroscopy is an ideal framework for investigating photoionization shake-up satellites. Their important intensity in a single site double core hole (ssDCH) spectrum allows the exploration of the subtle mix of relaxation and correlation effects associated with the inherent multielectronic character of the shake-up process. We present a high-accuracy computation method for single photon double core-shell photoelectron spectra that combines a selected configuration interaction procedure with the use of non-orthogonal molecular orbitals to obtain unbiased binding energy and intensity. This strategy leads to the oxygen ssDCH spectrum of the CO molecule that is in excellent agreement with the experimental result. Through a combined wave function and density analysis, we highlight that the most intense shake-up satellites are characterized by an electronic reorganization that opposes the core hole-induced relaxation.

Zeeman quantum beats of helium Rydberg states excited by synchrotron radiation.

Quantum beats in fluorescence decay from Zeeman-split magnetic sublevels have been measured for helium Rydberg states excited by synchrotron radiation. The Zeeman quantum beats observed in this prototypical case were fitted with an equation from a theoretical formulation. It is proposed that Zeeman quantum beat measurement can be a useful way to simply evaluate the polarization characteristics of extreme ultraviolet light.

Probing molecular bond-length using molecular-frame photoelectron angular distributions.

The molecular-frame photoelectron angular distributions (MFPADs) in O 1s photoemission from CO2 molecule were measured. Patterns due to photoelectron diffractions were observed in the MFPADs. The polarization-averaged MFPADs were compared with theoretical calculation and were found to be useful in determining the molecular bond-length, which is a component to determine molecular structures.

Pressure-induced local symmetry breaking upon liquid-liquid transition of GeI4 and SnI4.

SnI4 and GeI4 have been confirmed to have another liquid state appearing on compression. To identify the microscopic pathway from the low- to high-pressure liquid states, the structure of these liquids in the appropriate thermodynamic regions was analyzed using a reverse Monte Carlo method. The occurrence of pressure-induced symmetry lowering of molecules, from regular tetrahedral to ammonia-like pyramidal symmetry, was then recognizable in these systems. This symmetry lowering is reflected in the change in shape of the molecular form factor. The latter change occurs abruptly near the expected transition pressure in liquid SnI4, whereas it proceeds gradually in GeI4. This is consistent with our observation that SnI4 seems to undergo a first-order liquid-liquid transition, whereas the transition seems to end up with a crossover in liquid GeI4. Interestingly, when the molecular density becomes high, it is possible for the two-body intermolecular interaction to have a double-minimum character, which offers two characteristic length scales corresponding to two liquid states with different densities. However, quantum chemical calculations show that molecular deformation for this type of symmetry lowering results in an increase in electronic energy, which leaves the problem of the physical origin for this anisotropic deformation. We speculate that this symmetry lowering occurs as a precursor to the whole change in the liquid structure.

Superfluorescence, Free-Induction Decay, and Four-Wave Mixing: Propagation of Free-Electron Laser Pulses through a Dense Sample of Helium Ions.

We report an experimental and numerical study of the propagation of free-electron laser pulses (wavelength 24.3 nm) through helium gas. Ionization and excitation populates the He^{+} 4p state. Strong, directional emission was observed at wavelengths of 469, 164, 30.4, and 25.6 nm. We interpret the emissions at 469 and 164 nm as 4p-3s-2p cascade superfluorescence, that at 30.4 nm as yoked superfluorescence on the 2p-1s transition, and that at 25.6 nm as free-induction decay of the 3p state.

Observation of an optical vortex beam from a helical undulator in the XUV region.

The observation of an optical vortex beam at 60 nm wavelength, produced as the second-harmonic radiation from a helical undulator, is reported. The helical wavefront of the optical vortex beam was verified by measuring the interference pattern between the vortex beam from a helical undulator and a normal beam from another undulator. Although the interference patterns were slightly blurred owing to the relatively large electron beam emittance, it was possible to observe the interference features thanks to the helical wavefront of the vortex beam. The experimental results were well reproduced by simulation.

Hard-X-Ray-Induced Multistep Ultrafast Dissociation.

Creation of deep core holes with very short (τ≤1 fs) lifetimes triggers a chain of relaxation events leading to extensive nuclear dynamics on a few-femtosecond time scale. Here we demonstrate a general multistep ultrafast dissociation on an example of HCl following Cl 1s→σ^{*} excitation. Intermediate states with one or multiple holes in the shallower core electron shells are generated in the course of the decay cascades. The repulsive character and large gradients of the potential energy surfaces of these intermediates enable ultrafast fragmentation after the absorption of a hard x-ray photon.

Successful pregnancy by vitrified-warmed embryo transfer for a woman with Kallmann syndrome.

Purpose: Kallmann syndrome is a genetic disorder characterized by hypogonadotropic hypogonadism and anosmia. We report the case of a 31-year-old woman with Kallmann syndrome who successfully gave birth after intracytoplasmic sperm injection (ICSI) and vitrified-warmed embryo transfer, despite relatively ineffective ovarian stimulation. Method: A 30 year-old woman with primary amenorrhea wished to achieve pregnancy. Diagnostic testing results were consistent with Kallmann syndrome. Follicular stimulation was started with human menopausal gonadotropin (hMG; 150 IU/day). After 28 days of treatment, 4 follicles were observed (total hMG; 4200 IU), with a dominant follicle diameter of 23 mm. Ovum pick-up was performed and 2 oocytes, one at metaphase II (MII) and one at the germinal vesicle stage, were obtained. Piezo-ICSI was performed on the MII oocyte and an 8-cell stage embryo was cryopreserved on day 3. Subsequently, embryo transfer was performed after endometrial preparation. Result: A gestational sac and embryo heart activity were confirmed by ultrasonographic monitoring, and a healthy male infant weighing 3246 g was delivered by Caesarean section after 41 weeks 3 days of gestation. Conclusion: This is the first report of a healthy delivery after vitrified-warmed embryo transfer for a woman with Kallmann syndrome. Our experience suggests that ICSI and vitrified-warmed embryo transfer are effective for women with Kallmann syndrome.

sHLA-G and sHLA-I levels in follicular fluid are not associated with successful implantation.

In the field of in vitro fertilization (IVF), useful markers for the prediction of successful implantation for oocyte or embryo selection are essential. It has been reported that sHLA-G (sHLA-G1/HLA-G5) could be detected in the supernatant of the fertilized embryo and in follicular fluid samples (FFs), and that the presence of sHLA-G was related to successful implantation. If sHLA-G could be used as a marker of oocyte selection from multiple FFs, oocytes could be selected without physical contact, thus reducing the likelihood of damage. To investigate the potential for sHLA-G as a marker of oocyte selection from multiple FFs in one patient, protein levels of total protein, sHLA-G, and sHLA-I (sHLA-A, B, and C) were examined in FFs. The variation among multiple FFs in total protein level and sHLA-G level was not related to successful pregnancy. The average sHLA-I levels did not differ in the successful implantation and unsuccessful implantation groups, indicating that sHLA-I levels were not related to successful pregnancy. Furthermore, sHLA-G in FFs was not detected by western blotting, despite being detected by ELISA, while sHLA-I was detected by both ELISA and western blot. These data suggest that sHLA-G in FF might not be a useful marker for oocyte selection as measurements of sHLA-G were inconsistent and there was no association with successful pregnancy. Further, more rigorously tested ELISA systems for detecting sHLA-G in body fluids are necessary before the utility of sHLA-G for diagnosis can be established.

Double core-hole creation by sequential attosecond photoionization.

X-ray fluorescence spectroscopy demonstrates that a single core-hole krypton with a 170-as lifetime can be photoionized again to a double core-hole state by an intense x-ray pulse. The observation indicates that unconventional interaction between intense x rays and atoms is no more negligible in applications with x-ray free-electron lasers. Quantitative analysis of the double core-hole creation including effects of a pulsed and spiky temporal structure enables estimation of the x-ray pulse duration in the sub-10-fs range.