Polaron Masses in CH₃NH₃PbX₃ Perovskites Determined by Landau Level Spectroscopy in Low Magnetic Fields

次世代太陽電池材料 ペロブスカイト半導体中の「電子の重さ」の評価に成功 --太陽電池やLED応用へ向けてさらなる期待--. 京都大学プレスリリース. 2021-06-14.We investigate the electron-phonon coupling in CH₃NH₃PbX₃ lead halide perovskites through the observation of Landau levels and high-order excitons at weak magnetic fields, where the cyclotron energy is significantly smaller than the longitudinal optical phonon energy. The reduced masses of the carriers and the exciton binding energies obtained from these data are clearly influenced by polaron formation. We analyze the field-dependent polaronic and excitonic properties, and show that they can be quantitatively reproduced by the Fröhlich large polaron model

A study on cross-reactivity of anti-DNA antibody with glycosaminoglycans.

To study the pathogenesis of lupus nephritis, the cross reactivity between anti-DNA antibody and glycosaminoglycans (GAGs) was investigated. Monoclonal anti-DNA antibodies were obtained from hybridomas by the fusion of MRL/lpr/lpr splenocytes with murine myeloma cells. Some of these monoclonal anti-DNA antibodies showed cross reactivity with GAGs, such as hyaluronic acid, chondroitin sulfate and heparan sulfate. To elucidate the mechanism of cross reactivity, inhibition assays with propanol and polyethylenimine (PEI), a cationic agent, were carried out. Increase of the concentration of PEI (0.6-2.0% vol/vol) resulted in a dose dependent decrease in the binding ability of anti-DNA antibody to GAGs. Propanol, an organic reagent which disrupts the van der Waals bonds between epitopes and paratopes, showed little inhibitory effect on the binding activity of monoclonal anti-DNA antibody to GAGs. These results indicate that the binding of anti-DNA antibody to GAGs is due to a charge interaction rather than van der Waals forces. Anti-DNA antibody which can react with GAGs in the glomerular basement membrane seems to play an important role in the pathogenesis of lupus nephritis.</p

Molecular sieve in bovine descemets membrane as revealed by negative staining.

Descemet's membrane was isolated from the corneas of cows and observed by electron microscopy after negative staining with 1% phosphotungstic acid solution, pH 7.2. Ultrastructurally, bovine Descement's membrane had a very regular hexagonal pattern. Nodes were connected to the six others around each of them by thin filaments to form a hexagon. The distance between the nodes was approximately 120 nm, the diameter of the nodes approximately 30 nm, and the width of the connecting filaments approximately 10 nm. Bovine Descement's membrane was a molecular sieve composed of nodes and filaments substantiating our molecular sieve theory of basement membranes.</p

Spred-2 deficiency exacerbates acetaminophen-induced hepatotoxicity in mice

MAPKs are involved in acetaminophen (APAP)-hepatotoxicity, but the regulatory mechanism remains unknown. Here, we explored the role of Spred-2 that negatively regulates Ras/ERK pathway in APAP-hepatotoxicity. Spred-2 knockout (KO) mice demonstrated exacerbated liver injury, an event that was associated with increased numbers of CD4(+) T, CD8(+) T and NK cells in the liver compared to the control. Levels of CXCL9/CXCL10 that attract and activate these cells were increased in Spred-2 KO-liver. Kupffer cells isolated from Spred-2 KO mice after APAP challenge expressed higher levels of CXCL9/CXCL10 than those from the control. Upon stimulation with APAP or IFN gamma, naive Kupffer cells from Spred-2 KO mice expressed higher levels of CXCL9/CXCL10. NK cell-depletion attenuated APAP-hepatotoxicity with lowered hepatic IFN gamma and decreased numbers of not only NK cells but also CD4(+) T and CD8(+) T cells in the liver. These results suggest that Spred-2 negatively regulates APAP-hepatotoxicity under the control of Kupffer cells and NK cells

Incidentally found abdominal para-aortic and inferior mesenteric root lymph node metastases of prostatic adenocarcinoma in a surgical case with sigmoid colon cancer

We report a rare case of incidentally found metastatic adenocarcinoma in the abdominal para-aortic and inferior mesenteric root lymph nodes originating from the prostate, at the time of surgery in a patient with sigmoid colon cancer. A man in his mid-seventies was scheduled to undergo laparoscopic-assisted sigmoidectomy and regional lymph node dissection. At the beginning of laparoscopic surgery, a caterpillar-like swelling of abdominal para-aortic lymph nodes was found; the diagnosis using frozen sections was a metastatic adenocarcinoma showing cribriform and solid growth patterns different from typical colorectal cancer. The surgical procedure was changed to an abdominal sigmoidectomy with widely extended lymph node dissection, including inferior mesenteric root lymph nodes and sampling of abdominal para-aortic lymph nodes. The resected sigmoid colon cancer was a papillary/tubular adenocarcinoma invading the muscularis with no lymph node metastasis (pT2N0M0/pStage IIA). Additionally, the presence of a metastatic adenocarcinoma showing cribriform and solid growth patterns different from the primary sigmoid colon cancer was confirmed in the abdominal para-aortic and inferior mesenteric root lymph nodes. The metastatic adenocarcinoma cells were positive for prostate-specific antigen (PSA) and negative for CDX2, indicating that the tumor was from the prostate. A total of ten prostatic core needle biopsy specimens also contained a usual (acinar) adenocarcinoma, with a Gleason score of 4 + 5 = 9. Androgen blockade was performed; the serum PSA level was reduced to 0.06 nanograms per microliter in the subsequent five months. Regardless of radiologic images, examination of serum PSA level is recommended before surgery in male surgical colorectal cancer patients more than 60 years old