Pressure-induced reversal of Peierls-like distortions elicits the polyamorphic transition in GeTe and GeSe.

While polymorphism is prevalent in crystalline solids, polyamorphism draws increasing interest in various types of amorphous solids. Recent studies suggested that supercooling of liquid phase-change materials (PCMs) induces Peierls-like distortions in their local structures, underlying their liquid-liquid transitions before vitrification. However, the mechanism of how the vitrified phases undergo a possible polyamorphic transition remains elusive. Here, using high-energy synchrotron X-rays, we can access the precise pair distribution functions under high pressure and provide clear evidence that pressure can reverse the Peierls-like distortions, eliciting a polyamorphic transition in GeTe and GeSe. Combined with simulations based on machine-learned-neural-network potential, our structural analysis reveals a high-pressure state characterized by diminished Peierls-like distortion, greater coherence length, reduced compressibility, and a narrowing bandgap. Our finding underscores the crucial role of Peierls-like distortions in amorphous octahedral systems including PCMs. These distortions can be controlled through pressure and composition, offering potentials for designing properties in PCM-based devices.

Pair Distribution Function from Liquid Jet Nanoparticle Suspension using Femtosecond X-ray Pulses.

X-ray scattering data measured on femtosecond timescales at the SACLA X-ray Free Electron Laser (XFEL) facility on a suspension of HfO2 nanoparticles in a liquid jet were used for pair distribution function (PDF) analysis. Despite a non-optimal experimental setup resulting in a modest Qmax of ~8 Å-1 , a promising PDF was obtained. The main features were reproduced when comparing the XFEL PDF to a PDF obtained from data measured at the PETRA III synchrotron light source. Refining structural parameters such as unit cell dimension and particle size from the XFEL PDF provided reliable values. Although the reachable Qmax limited the obtainable information, the present results indicate that good quality PDFs can be obtained on femtosecond timescales if the experimental conditions are further optimized. The study therefore encourages a new direction in ultrafast structural science where structural features of amorphous and disordered systems can be studied.

Towards pump-probe single-crystal XFEL refinements for small-unit-cell systems.

Serial femtosecond crystallography for small-unit-cell systems has so far seen very limited application despite obvious scientific possibilities. This is because reliable data reduction has not been available for these challenging systems. In particular, important intensity corrections such as the partiality correction critically rely on accurate determination of the crystal orientation, which is complicated by the low number of diffraction spots for small-unit-cell crystals. A data reduction pipeline capable of fully automated handling of all steps of data reduction from spot harvesting to merged structure factors has been developed. The pipeline utilizes sparse indexing based on known unit-cell parameters, seed-skewness integration, intensity corrections including an overlap-based combined Ewald sphere width and partiality correction, and a dynamically adjusted post-refinement routine. Using the pipeline, data measured on the compound K4[Pt2(P2O5H2)4]·2H2O have been successfully reduced and used to solve the structure to an R1 factor of ∼9.1%. It is expected that the pipeline will open up the field of small-unit-cell serial femtosecond crystallography experiments and allow investigations into, for example, excited states and reaction intermediate chemistry.

Synchrotron X-ray Electron Density Analysis of Chemical Bonding in the Graphitic Carbon Nitride Precursor Melamine.

Melamine is a precursor and building block for graphitic carbon nitride (g-CN) materials, a group of layered materials showing great promise for catalytic applications. The synthetic pathway to g-CN includes a polycondensation reaction of melamine by evaporation of ammonia. Melamine molecules in the crystal organize into wave-like planes with an interlayer distance of 3.3 Šsimilar to that of g-CN. Here we present an extensive investigation of the experimental electron density of melamine obtained from modelling of synchrotron radiation X-ray single-crystal diffraction data measured at 25 K with special focus on the molecular geometry and intermolecular interactions. Both intra- and interlayer structures are dominated by hydrogen bonding and π-interactions. Theoretical gas-phase optimizations of the experimental molecular geometry show that bond lengths and angles for atoms in the same chemical environment (C-N bonds in the ring, amine groups) differ significantly more for the experimental geometry than for the gas-phase-optimized geometries, indicating that intermolecular interactions in the crystal affects the molecular geometry. In the experimental crystal geometry, one amine group has significantly more sp3 -like character than the others, hinting at a possible formation mechanism of g-CN. Topological analysis and energy frameworks show that the nitrogen atom in this amine group participates in weak intralayer hydrogen bonding. We hypothesize that melamine condenses to g-CN within the layers and that the unique amine group plays a key role in the condensation process.

The relationship between the distinct ratios of benserazide and carbidopa to levodopa and motor complications in Parkinson's disease: A retrospective cohort study.

BACKGROUND: In Japan, only two medications of immediate-release levodopa with distinct ratios of decarboxylase inhibitor (DCI), namely levodopa/benserazide 100/25 mg and levodopa/carbidopa 100/10 mg, are available for the treatment of Parkinson's disease (PD). The relationship between the difference in the DCI to levodopa ratio and the development of motor complications in long-term administration of levodopa is unknown. PURPOSE: We assessed the duration from initiation of levodopa/DCI to the emergence of motor fluctuations in patients with PD treated with levodopa/benserazide and levodopa/carbidopa. METHODS: We retrospectively assessed the disease course, especially the period from the onset of motor symptoms or initiation of levodopa/DCI to the emergence of motor fluctuations, in patients with PD who were initially treated with either levodopa/benserazide (300/75 mg/day) or levodopa/carbidopa (300/30 mg/day). RESULTS: Of the 186 candidates, 52 patients were enrolled. The mean duration to the emergence of motor fluctuations in the levodopa/carbidopa group was significantly longer than that in the levodopa/benserazide group (5.0 ± 1.4 vs 3.1 ± 1.2 years, p < 0.01). The mean duration from onset of motor symptoms to the emergence of motor fluctuations in the levodopa/carbidopa group was also significantly longer than that in the levodopa/benserazide group (6.6 ± 1.6 vs 4.7 ± 1.3 years, p < 0.01). CONCLUSION: Our study suggests that levodopa/carbidopa therapy with a DCI to levodopa ratio of 1:10 may delay the occurrence of motor fluctuations when compared to levodopa/benserazide therapy with that of 1:4. The difference in the blending ratio of levodopa/DCI may influence the disease progression in PD.

Direct observation of one-dimensional disordered diffusion channel in a chain-like thermoelectric with ultralow thermal conductivity.

Structural disorder, highly effective in reducing thermal conductivity, is important in technological applications such as thermal barrier coatings and thermoelectrics. In particular, interstitial, disordered, diffusive atoms are common in complex crystal structures with ultralow thermal conductivity, but are rarely found in simple crystalline solids. Combining single-crystal synchrotron X-ray diffraction, the maximum entropy method, diffuse scattering, and theoretical calculations, here we report the direct observation of one-dimensional disordered In1+ chains in a simple chain-like thermoelectric InTe, which contains a significant In1+ vacancy along with interstitial indium sites. Intriguingly, the disordered In1+ chains undergo a static-dynamic transition with increasing temperature to form a one-dimensional diffusion channel, which is attributed to a low In1+-ion migration energy barrier along the c direction, a general feature in many other TlSe-type compounds. Our work provides a basis towards understanding ultralow thermal conductivity with weak temperature dependence in TlSe-type chain-like materials.

Recurrent HyperCKemia with Immunological Involvement of the Endomysial Capillaries in Neuromyelitis Optica.

A 55-year-old woman with neuromyelitis optica (NMO) had recurrent myalgias with hyperCKemia. A muscle biopsy suggested nonspecific myopathic changes. Regarding immunohistochemistry, the expression of both major histocompatibility complex class I and myxovirus resistance protein A was observed in the endomysial capillaries, suggesting immunological involvement of these capillaries, whereas both C5b9 (membrane attack complex) and aquaporin 4 immunofluorescence stainings were normal. The present findings led us to conclude that one possible mechanism for hyperCKemia in NMO underlying the immunological involvement of the endomysial capillaries was an as-yet-unidentified factor that triggered damage to the integrity of the sarcolemma and thereby cause CK leakage into the serum.

Prognostic evaluation of branch atheromatous disease in the pons using carotid artery ultrasonography.

BACKGROUND: Branch atheromatous disease is an ischemic stroke, involving occlusion or severe stenosis of the perforating artery, causing neurologic symptoms and serious sequelae. We aimed to investigate initial morphometric and hemodynamic characteristics of the vertebral artery immediately post-onset to predict lesion expanding. METHODS: This case-control study collected demographic, historical, and physical examination data from 44 patients with branch atheromatous disease in the pons at admission. The maximum ischemic pons area and stenosis rate in the basilar artery were calculated using magnetic resonance images. Diameter, velocity, and flow volume of the vertebral arteries were measured using carotid artery ultrasonography. Correlations between ischemic lesion extent and these parameters were investigated. RESULTS: Patients were assigned to groups of less (Group 1) or more (Group 2) than the median maximum ischemic area in the pons, calculated from magnetic resonance images (121.6 mm2). Modified Rankin scale scores were significantly worse in Group 2. Blood pressure and blood findings were similar between groups. Group 2 showed significantly higher basilar artery stenosis rates. Flow volume, velocity, peak systolic velocity, and end-diastolic velocity in the vertebral artery on both sides were significantly decreased in Group 2. CONCLUSIONS: Deteriorated vertebral artery hemodynamics caused a more extensive ischemic lesion in branch atheromatous disease in the pons. Evaluation of the vertebral using carotid artery ultrasonography in the acute phase may be useful for predicting disease progression.

Nonsystemic vasculitic neuropathy in a patient with IgG-monoclonal gammopathy of undetermined significance: A case report.

RATIONALE: Monoclonal gammopathy of undetermined significance (MGUS) is a plasma cell proliferative disorder that consistently precedes multiple myeloma. Peripheral neuropathy in patients with IgG-MGUS tends to vary in clinical phenotype. We report a rare case of a patient with IgG-MGUS who had nonsystemic vasculitic neuropathy (NSVN). PATIENT CONCERNS: A 56-year-old Japanese woman presented with progressive sensory ataxia with episodic paresthesia. Her clinical and laboratory values were compatible with IgG-MGUS. A nerve conduction study suggested possible chronic inflammatory demyelinating polyneuropathy. However, intravenous immunoglobulin therapy was not effective. A sural nerve biopsy specimen revealed mildly reduced myelinated fiber density and myelin ovoid formation, with epineural arterioles infiltrated by inflammatory cells. DIAGNOSES: We accordingly diagnosed her condition as NSVN. INTERVENTIONS: She was accordingly started on oral prednisolone (40 mg/d) at 3 months after the onset of her neurological symptoms. OUTCOMES: At 1 year after the oral prednisolone treatment was begun, the patient's neurological symptoms showed no worsening. LESSONS: These findings indicate NSVN as a possible cause of peripheral neuropathy in patients with IgG-MGUS. Cumulatively, our findings highlight the need for a nerve biopsy for peripheral neuropathy in patients with IgG-MGUS as a possible cause of NSVN. The early diagnosis of NSVN is expected to be beneficial for such patients.

A flexible proximity sensor formed by duplex screen/screen-offset printing and its application to non-contact detection of human breathing.

We describe a flexible capacitance-type sensor that can detect an approaching human without contact, fabricated by developing and applying duplex conductive-ink printing to a film substrate. The results of our calculations show that the difference in size between the top and bottom electrodes of the sensor allows for the spatial extension of the electric field distribution over the electrodes. Hence, such a component functions as a proximity sensor. This thin and light device with a large form factor can be arranged at various places, including curved surfaces and the back of objects such that it is unnoticeable. In our experiment, we attached it to the back of a bed, and found that our device successfully detected the breathing of a subject on the bed without contacting his body. This should contribute to reducing the physical and psychological discomfort among patients during medical checks, or when their condition is being monitored.

Efficient Detection and Purification of Cell Populations Using Synthetic MicroRNA Switches.

Isolation of specific cell types, including pluripotent stem cell (PSC)-derived populations, is frequently accomplished using cell surface antigens expressed by the cells of interest. However, specific antigens for many cell types have not been identified, making their isolation difficult. Here, we describe an efficient method for purifying cells based on endogenous miRNA activity. We designed synthetic mRNAs encoding a fluorescent protein tagged with sequences targeted by miRNAs expressed by the cells of interest. These miRNA switches control their translation levels by sensing miRNA activities. Several miRNA switches (miR-1-, miR-208a-, and miR-499a-5p-switches) efficiently purified cardiomyocytes differentiated from human PSCs, and switches encoding the apoptosis inducer Bim enriched for cardiomyocytes without cell sorting. This approach is generally applicable, as miR-126-, miR-122-5p-, and miR-375-switches purified endothelial cells, hepatocytes, and insulin-producing cells differentiated from hPSCs, respectively. Thus, miRNA switches can purify cell populations for which other isolation strategies are unavailable.

Factors affecting the development of somatic cell nuclear transfer embryos in Cattle.

Nuclear transfer is a complex multistep procedure that includes oocyte maturation, cell cycle synchronization of donor cells, enucleation, cell fusion, oocyte activation and embryo culture. Therefore, many factors are believed to contribute to the success of embryo development following nuclear transfer. Numerous attempts to improve cloning efficiency have been conducted since the birth of the first sheep by somatic cell nuclear transfer. However, the efficiency of somatic cell cloning has remained low, and applications have been limited. In this review, we discuss some of the factors that affect the developmental ability of somatic cell nuclear transfer embryos in cattle.

Developmental ability of somatic cell nuclear transferred embryos aggregated at the 8-cell stage or 16- to 32-cell stage in cattle.

Aggregation of somatic cell nuclear transfer (SCNT) embryos in mice is reported to improve full-term development. In the present study, we attempted to improve the development of SCNT embryos by aggregation in cattle. In Experiment 1, to examine the effect of the timing of aggregation on in vitro development of cumulus-cell NT embryos, we aggregated two or three SCNT embryos (2X or 3X embryos) at the 1-cell, 8-cell and 16- to 32-cell stages. Irrespective of the timing of aggregation, 3X embryos developed to the blastocyst stage at a high rate. However, aggregation did not improve the total blastocyst formation rate of the embryos used. The cell numbers of 3X embryos aggregated at the 1-cell stage and 2X embryos tended to be higher than that of single NT embryos (1X embryos). Furthermore, a significant increase in cell number was observed in 3X embryos aggregated at the 8-cell stage and 16- to 32-cell stage. In Experiment 2, we used fibroblast cells as nuclear donors and examined in vitro development of 3X embryos aggregated at the 8-cell stage and 16- to 32-cell stage. As a result, 3X embryos had high blastocyst formation rates and higher cell numbers than 1X embryos, which was consistent with the results of Experiment 1. In Experiment 3, we examined the full-term developmental ability of 3X embryos aggregated at the 8-cell stage and 16- to 32-cell stage. After transfer of fibroblast-derived NT embryos into recipient animals, a significantly higher pregnancy rate was obtained on Day 60 in 3X embryos than in 1X embryos. Two embryos aggregated at 8-cell stage and one embryo aggregated at the 16- to 32-cell stage developed to term, while no pregnancies derived from 1X embryos that lasted to Day 60. However, two of the cloned calves were stillborn. These results suggest that aggregation of the 8-cell stage or 16- to 32-cell stage SCNT embryos may improve the pregnancy rate, but that it cannot reduce the high incidence of fetal loss and stillbirth, which is often observed in bovine SCNT.

Treatment with a histone deacetylase inhibitor after nuclear transfer improves the preimplantation development of cloned bovine embryos.

We examined the effects of treatment with histone deacetylase inhibitors (HDACi), trichostatin A (TSA) and scriptaid (SCR), on the blastocyst formation rate in bovine somatic cell nuclear transferred (SCNT) embryos derived from fibroblast cells. Three fibroblast cell lines (L1, L2 and L3) were used as somatic cell donors to produce SCNT embryos (L1, L2 and L3 embryos, respectively). In Experiment 1, we compared the in vitro developmental competence of L1 embryos treated with various concentrations of TSA for different time periods following chemical activation. Embryos treated with 5 nM TSA for 20 h showed a significantly increased blastocyst formation rate compared with untreated controls. In Experiment 2, we examined the effect of TSA (5 nM) treatment of L1, L2 and L3 embryos as well as the effect of treatment of L1, L2 and L3 embryos with various concentrations of SCR on in vitro developmental competence. It was found that 5 nM TSA treatment significantly increased the blastocyst formation rate in L1 and L3 embryos but did not have an influence on the development of L2 embryos. On the other hand, 5 nM SCR treatment significantly increased the blastocyst formation rates of L1 and L2 embryos compared with controls. However, there was no significant increase in the blastocyst formation rate of L3 embryos when they were treated with SCR. In Experiment 3, acetylation of H4K12 was examined in donor cells and pronuclear-stage L1, L2 and L3 embryos treated with 5 nM TSA or 5 nM SCR by immunostaining. The level of H4K12 acetylation was different among donor cells. The staining intensities in the TSA-treated L1 and L3 embryos and SCR-treated L2 embryos were significantly higher than those of untreated embryos. These results suggest that HDACi treatment of bovine SCNT embryos improves the blastocyst formation rate; however, the optimal treatment conditions may differ among donor cell lines.

Culture of bovine embryos on a polydimethylsiloxane (PDMS) microwell plate.

We fabricated a polydimethylsiloxane (PDMS)-based microwell plate (PDMS-MP) containing 100 microwells with a rounded bottom and examined whether it can be used for culture of individual in vitro fertilized (IVF) embryos or parthenogenetically activated zona-free embryos in cattle. In Experiment 1, we examined the in vitro developmental ability of IVF embryos cultured individually on PDMS-MP. After IVF, 20 embryos were transferred into 100 microl drops on PDMS-MP and cultured individually in each well of PDMS-MP (PDMS group). After 7 days of culture, the embryos in the PDMS group developed to the blastocyst stage at the same rate of those in the control group cultured in a group of 20 embryos without PDMS-MP. There were no differences in total number of cells and the ratio of inner cell mass to total cells between the PDMS and control groups. In Experiment 2, we examined the in vitro developmental ability of parthenogenetically activated zona-free bovine embryos cultured individually on PDMS-MP. The zona-free embryos were cultured individually in each well of a PDMS-MP or in each well produced by pressing a darning needle onto the bottom of a culture dish (WOW group). After 7 days of culture, the blastocyst formation rate and cell number of blastocysts in the PDMS group did not differ from those of the zona-intact embryos in the control group. Also, there were no differences in the blastocyst formation rate and cell number of blastocysts between the WOW and PDMS groups. These results suggest that the culture system using PDMS-MP is useful for individual embryos or zona-free embryos in cattle.

Microinjection of serum-starved mitochondria derived from somatic cells affects parthenogenetic development of bovine and murine oocytes.

Microinjection of isolated mitochondria into oocytes is an effective method to introduce exogenous mitochondrial DNA. In nuclear transfer procedures in which donor cell mitochondria are transferred with nuclei into recipient oocytes; development and survival rates of reconstructed embryos may be also directly influenced by mitochondrial viability. Mitochondrial viability is dramatically affected by cell culture conditions, such as serum starvation prior to nuclear transfer. This study was conducted to examine the influence of exogenous mitochondria using bovine and mouse parthenogenetic models. Mitochondria were isolated from primary cells at confluency and after serum starvation. The bovine oocytes injected with serum-starved mitochondria showed lower rates of morula and blastocyst formation when compared to uninjected controls (P<0.05). However, the developmental rates between non-starved mitochondria injection and controls were not different (P>0.05). The murine oocytes injected with serum-starved mitochondria showed lower rates of development when compared with non-starved mitochondria and controls (P<0.01). In contrast to mitochondria transfer, ooplasm transfer did not affect murine or bovine parthenogenetic development (P>0.05). The overall results showed that injection of serum-starved mitochondria influenced parthenogenetic development of both bovine and murine oocytes. Our results illustrate that the somatic mitochondria introduction accompanying nuclei has the capacity to affect reconstructed embryo development; particularly when using serum-starved cells as donor cells.

Bovine nuclear transfer using fresh cumulus cell nuclei and in vivo- or in vitro-matured cytoplasts.

We examined the effects of the source of recipient oocytes and timing of fusion and activation on the development competence of bovine nuclear transferred (NT) embryos derived from fresh cumulus cells isolated immediately after collection by ovum pickup (OPU). As recipient cytoplasts, we used in vivo-matured oocytes collected from hormone-treated heifers by OPU, or in vitro-matured oocytes from slaughterhouse-derived ovaries. NT embryos were chemically activated immediately (simultaneous fusion and activation, FA) or 2 h (delayed activation, DA) after fusion. When in vitro-matured oocytes were used as recipient cytoplasts, the development rate to the blastocyst stage of NT embryos produced by the DA method (23%) tended to be higher than those by the FA method (15%), but the difference was not significant. NT embryos derived from in vivo-matured cytoplasts have a high blastocyst yield (46%). Pregnancy rate at day 35 did not differ with the timing of fusion and activation (FA vs. DA; 50% vs. 44%) or oocyte source (in vivo- vs. in vitro-matured; 50% vs. 44%). Subsequently, the high fetal losses (88% of pregnancies) were observed with in vitro-matured cytoplasts, whereas no abortions were observed in NT fetuses from in vivo-matured cytoplasts. A total of three embryos derived from fresh cumulus cells developed to term. However, all three cloned calves were stillborn. These results indicate that improvement of development competence after NT is possible by using in vivo-matured oocytes as recipient cytoplasts in bovine NT.

Characterization of a donor mitochondrial DNA transmission bottleneck in nuclear transfer derived cow lineages.

In embryos derived by nuclear-transfer (NT), fusion of donor cells with recipient oocytes resulted in varying patterns of mitochondrial DNA (mtDNA) transmission in NT animals. Distribution of donor cell mtDNA (D-mtDNA) found in offspring of NT-derived founders may also vary from donor cell and host embryo heteroplasmy to host embryo homoplasmy. Here we examined the transmission of mtDNA from NT cows to G(1) offspring. Eleven NT founder cows were produced by fusion of enucleated oocytes (Holstein/Japanese Black) with Jersey/ Holstein oviduct epithelial cells, or Holstein/Japanese Black cumulus cells. Transmission of mtDNA was analyzed by PCR mediated single-strand conformation polymorphism of the D-loop region. In six of seven animals sampled postmortem, heteroplasmy were detected in various tissues, while D-mtDNA could not be detected in blood or hair samples from four live animals. The average proportion of D-mtDNA detected in one NT cow was 7.6%, and those in other cows were <5%. Heteroplasmic NT cows (n = 6) generated a total 12 G(1) offspring. Four of 12 G(1) offspring exhibited high percentages of D-mtDNA populations (range 17-51%). The remaining eight G(1) offspring had slightly or undetectable D-mtDNA (<5%). Generally, a genetic bottleneck in the female germ-line should favor a homoplasmic state. However, proportions of some G(1) offspring maintained heteroplasmy with a much higher percentage of D-mtDNA than their NT dams, which may also reflect a segregation distortion caused by the proposed mitochondrial bottleneck. These results demonstrate that D-mtDNA in NT cows is transmitted to G(1) offspring with varying efficiencies.

In vitro development of equine oocytes from preserved ovaries after intracytoplasmic sperm injection.

In this study, we evaluated the meiotic competence of equine oocytes from ovaries preserved for one day. We also investigated fertilization, cleavage rate, developmental competence and freezability of equine embryos after intracytoplasmic sperm injection (ICSI). After collection from ovaries, the oocytes were classified into two groups comprised of those having compact cumulus layers (Cp) or those having expanded cumulus layers (Ex). Oocytes with a first polar body were subjected to fertilization by ICSI using frozen-thawed stallion spermatozoa and were then cultured in CR1aa medium. The rates of metaphase II-stage oocytes, normal fertilization and cleavage were not significantly different between the two oocyte categories (38.5, 70.0 and 48.7% for CP and 43.5, 60.0 and 58.8% for Ex, respectively). However, the blastocyst development rate of Ex was significantly (P<0.05) higher than that of Cp (25.5 vs. 7.7%). Three Cp-derived and 12 Ex-derived early blastocysts were cryopreserved using the slow cooling protocol, and all of them developed to hatching blastocysts after thawing. These results suggest that equine oocytes fertilized by ICSI can develop to the preimplantation stage in culture conditions similar to those used in the bovine. Furthermore, the Ex oocytes had higher developmental competence than the Cp oocytes, and the in vitro-produced blastocysts had high viability after freezing and thawing.