Temperature-dependent evolutions of excitonic superfluid plasma frequency in a srong excitonic insulator candidate, Ta2_2NiSe5_5

We investigate an interesting anisotropic van der Waals material, Ta$_{2}$NiSe$_{5}$, using optical spectroscopy. Ta$_{2}$NiSe$_{5}$ has been known as one of the few excitonic insulators proposed over 50 years ago. Ta$_{2}$NiSe$_{5}$ has quasi-one dimensional chains along the $a$-axis. We have obtained anisotropic optical properties of a single crystal Ta$_{2}$NiSe$_{5}$ along the $a$- and $c$-axes. The measured $a$- and $c$-axis optical conductivities exhibit large anisotropic electronic and phononic properties. With regard to the $a$-axis optical conductivity, a sharp peak near 3050 cm$^{-1}$ at 9 K, with a well-defined optical gap ($\Delta^{EI} \simeq$ 1800 cm$^{-1}$) and a strong temperature-dependence, is observed. With an increase in temperature, this peak broadens and the optical energy gap closes around $\sim$325 K($T_c^{EI}$). The spectral weight redistribution with respect to the frequency and temperature indicates that the normalized optical energy gap ($\Delta^{EI}(T)/\Delta^{EI}(0)$) is $1-(T/T_c^{EI})^2$. The temperature-dependent superfluid plasma frequency of the excitonic condensation in Ta$_{2}$NiSe$_{5}$ has been determined from measured optical data. Our findings may be useful for future research on excitonic insulators.Comment: 17 pages, 5 figure

A Human Embryo of Carnegie Stage 13

A human embryo obtained from a salpinx resected for the treatment of an ectopic gestation was serially sectioned and observed. Four chambers of the heart were well delineated, though not completely separated. The dorsal pancreas was observed while the ventral pancreas was not yet formed. It was hard to clearly demarcate the cecal area because of no obvious dilatation. The septum transversum was nearly completely occupied by the hepatic parenchyme. The gall bladder-cyctic duct primordium was also observed. The intestine distal to the duodenum was attached to the posterior body wall by a prominent dorsal mesentery. The respiratory tree showed primary bronchi, and no mesenchymal differentiation around the tree was achieved yet. The mesonephric system showed variable developmental features depending on their location in the body. The mesonephric duct was already connected to the cloaca, and some localized dilatation of the duct surrounded by mesenchymal condensation, which would become the metanephric blastema, foretold the formation of the ureteric bud. The otocyst had been completely separated from the skin ectoderm and the endolymphatic duct had begun to form. Eye primordium observed was the optic cup. The well established lense placode impended to invaginate. Although this embryo showed a few characteristics of stage 14, it may be reasonable to regard this embryo as an older member of stage 13, considering the overall developmental status

A Human Embryo of Carnegie Stage 12

A human embryo obtained from a salpinx removed for the treatment of tubal gestation was serially sectioned and observed. On gross examination, the embryo showed three prominent pharyngeal arches, but not the cervical sinus. The upper arm bud had just begun to appear with a slight elevation in the skin ectoderm. Both the anterior and posterior neuropores had already been closed. The heart was at the cardiac loop stage. The respiratory diverticulum, the dorsal pancreas and the beginning of the omental bursa had appeared. In the pharyngeal region, the adenohypophyseal pocket and the thyroid anlage were observed. The optic evagination showed no regional differentiation yet. From the above findings, we concluded that this embryo belonged to Carnegie stage 12

The Globular Cluster System of M60 (NGC 4649). I. CFHT MOS Spectroscopy and Database

We present the measurement of radial velocities for globular clusters in M60, giant elliptical galaxy in the Virgo cluster. Target globular cluster candidates were selected using the Washington photometry based on the deep 16\arcmin \times 16\arcmin images taken at the KPNO 4m and using the $VI$ photometry derived from the HST/WFPC2 archive images. The spectra of the target objects were obtained using the Multi-Object Spectrograph (MOS) at the Canada-France-Hawaii Telescope (CFHT). We have measured the radial velocity for 111 objects in the field of M60: 93 globular clusters (72 blue globular clusters with $1.0\le(C-T_1)<1.7$ and 21 red globular clusters with $1.7\le(C-T_1)<2.4$), 11 foreground stars, 6 small galaxies, and the nucleus of M60. The measured velocities of the 93 globular clusters range from $\sim 500$ km s$^{-1}$ to $\sim 1600$ km s$^{-1}$, with a mean value of $1070_{-25}^{+27}$ km s$^{-1}$, which is in good agreement with the velocity of the nucleus of M60 ($v_{\rm gal}=1056$ km s$^{-1}$). Combining our results with data in the literature, we present a master catalog of radial velocities for 121 globular clusters in M60. The velocity dispersion of the globular clusters in the master catalog is found to be $234_{-14}^{+13}$ km s$^{-1}$ for the entire sample, $223_{-16}^{+13}$ km s$^{-1}$ for 83 blue globular clusters, and $258_{-31}^{+21}$ km s$^{-1}$ for 38 red globular clusters.Comment: 29 pages, 8 figures. To appear in Ap

Endometrial Stromal Sarcoma Presenting as Prevesical Mass Mimicking Urachal Tumor

Endometrial stromal sarcoma (ESS) is a mesenchymal neoplasm that usually occurs as a primary tumor of the uterine corpus, but rarely arises in other sites, such as the ovary, pelvic cavity, mesentery, omentum and intestine. Herein, we present a rare case of low-grade ESS presented as prevesical mass. A 60-yr-old woman who had undergone total hysterectomy for endometriosis eleven years ago was presented with incidentally detected prevesical pelvic mass. Since malignant transformation of urachal remnants was possible, the mass was suspected to be a urachal tumor. Extraction of the mass was performed, and the histopathologic diagnosis was low-grade ESS. In summary, prevesical tumor is rare but in patients with endometriosis, we suggest endometriosis and its possible malignant changes should be taken into account in the differential diagnosis of prevesical mass

Sustained, Photocatalytic CO₂ Reduction to CH₄ in a Continuous Flow Reactor by Earth-Abundant Materials: Reduced Titania-Cu₂O Z-Scheme Heterostructures

Photocatalytic conversion of CO₂ and water vapor to hydrocarbon fuels is a promising approach for storing solar energy while reducing greenhouse gas emissions. However, still certain issues including low product yields, limited photocatalyst stability and relatively high cost have hampered practical implementation of this technology. In the present work, a unique strategy is adopted to synthesize a stable, and inexpensive photocatalyst comprised of earth-abundant materials: a reduced titania-Cu₂O Z-scheme heterostructure. Under illumination for 6 h, the optimized reduced titania-Cu₂O photocatalyst enables 0.13 % photoreduction of highly diluted CO₂ with water vapors to 462nmol g⁻¹ of CH₄ while showing excellent stability over seven testing cycles (42 h). Our studies show the Z-scheme inhibits Cu₂O photocorrosion, while its synergistic effects with reduced titania result in sustained CH₄ formation in a continuous flow photoreactor. To the best of our knowledge stability exhibited by the reduced titania-Cu₂O Z-scheme is the highest for any Cu-based photocatalyst