Synthesis, characterization and its photoluminescence properties of group I-III-VI2 CuInS2 nanocrystals

We report the synthesis, characterization, and photoluminescence (PL) properties of colloidal I-III-VI2 CuInS2 and CuInS2/ZnS nanocrystals (NCs). Absorption shoulder and PL bands of the NCs are located at higher energy than those of band gap energy of bulk crystals due to a quantum-confinement effect. The PL band has a relatively large Stokes-shift, broad linewidth, and long decay-time, which suggests that the PL originates from a recombination of confined-excitions associated with donor(s) and/or acceptor(s). We found that quantum yield of the PL depends strongly on the photon-energy of excitation light and that it is up to 40-50% in resonant excitation at the energy positions corresponding to the absorption shoulder. Detailed properties and possible dynamics will be described. We also present preliminary results of PL properties focused on single NCs. There exist highluminescent NCs exhibiting so-called PL blinking as similar with II-VI NCs, while the others are dark NCs. 73.21.La, 78.47.jd, 78.67.Bf, 78.67.H

Synthesis, characterization, and its PL dynamics of colloidal type II CdTe/CdSe nanocrystals

We describe our improved synthesis and optical properties of high quality type II CdTe/CdSe nanocrystals (NCs). Specifically, clear shell-thickness dependences have been observed in the absorption and photoluminescence (PL) spectra and PL decay profiles as well. The magnitude of the lowest absorption band decreases drastically with large redshift as the shell thickness increases. The origin will be discussed on the bases of the model where the spatial configuration of the lowest electron-hole pair in the NCs changes from that of type I to type II as the shell thickness increases. As for the PL lifetime of the lowest electron-hole excitations, substantial increase is observed with increasing shell thickness. This can also be understood by considering the spatial configuration; spatial overlap between electron and hole wavefunctions decreases with increasing shell thickness, thus the lifetime increases. As for the NCs with extremely thin shell (∼1 ML; 1 ML = 0.35 nm), the PL lifetime seems much longer than expected. This suggests that the thin shells seem imperfect and work rather a kind of trap sites than layers

Synthesis, characterization, and its PL dynamics of colloidal type II CdTe/CdSe nanocrystals

We describe our improved synthesis and optical properties of high quality type II CdTe/CdSe nanocrystals (NCs). Specifically, clear shell-thickness dependences have been observed in the absorption and photoluminescence (PL) spectra and PL decay profiles as well. The magnitude of the lowest absorption band decreases drastically with large redshift as the shell thickness increases. The origin will be discussed on the bases of the model where the spatial configuration of the lowest electron-hole pair in the NCs changes from that of type I to type II as the shell thickness increases. As for the PL lifetime of the lowest electron-hole excitations, substantial increase is observed with increasing shell thickness. This can also be understood by considering the spatial configuration; spatial overlap between electron and hole wavefunctions decreases with increasing shell thickness, thus the lifetime increases. As for the NCs with extremely thin shell (∼1 ML; 1 ML = 0.35 nm), the PL lifetime seems much longer than expected. This suggests that the thin shells seem imperfect and work rather a kind of trap sites than layers

Synthesis and Antimicrobial Evaluation of Side-Chain Derivatives based on Eurotiumide A

Side-chain derivatives of eurotiumide A, a dihydroisochroman-type natural product, have been synthesized and their antimicrobial activities described. Sixteen derivatives were synthesized from a key intermediate of the total synthesis of eurotiumide A, and their antimicrobial activities against two Gram-positive bacteria, methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MSSA and MRSA), and a Gram-negative bacterium, Porphyromonas gingivalis, were evaluated. The results showed that derivatives having an iodine atom on their aromatic ring instead of the prenyl moiety displayed better antimicrobial activity than eurotiumide A against MSSA and P. gingivalis. Moreover, we discovered that a derivative with an isopentyl side chain, which is a hydrogenated product of eurotiumide A, is the strongest antimicrobial agent against all three strains, including MRSA

Phosphoinositide 3-kinase signaling pathway mediated by p110α regulates invadopodia formation

Inhibition of p110α or of the downstream PI3K signaling pathway components PDK1 and Akt, as well as phosphoinositide sequestration, blocks invadopodia formation in breast cancer cells

Suppression of cartilage degeneration by intra-articular injection of heparan sulfate 6-O endosulfatase in a mouse osteoarthritis model

We previously reported that heparan sulfate 6-O endosulfatases (Sulfs) were expressed in articular cartilage, and that the Sulf-1 knockout mouse developed severe knee osteoarthritis. In this study, we hypothesised that intra-articular injection of Sulf-1 would prevent cartilage degeneration. After confirming that 1 mg/ml Sulf-1 did not induce ATDC5 cell death in vitro, gene expression of type II collagen and matrix metalloproteinase (MMP)-13 in the presence of Sulf-1 (1-100 ng/ml) were determined by quantitative real-time polymerase chain reaction. Sulf-1 was also injected intra-articularly into mice following surgical destabilisation of the medial meniscus to produce a model of osteoarthritis, and cartilage degeneration was evaluated by safranin O and MMP-13 staining. We also investigated fibroblast growth factor 2 (FGF2)/ extracellular signal-regulated kinase (Erk) cell signalling by western blotting. Exposure to Sulf-1 in vitro increased type II collagen expression and decreased MMP-13 expression in a concentration-dependent manner. Sulf-1 injection into the mouse osteoarthritic knee significantly suppressed glycosaminoglycan loss and MMP-13 expression. Erk1/2 signalling pathway activation was significantly reduced by Sulf-1 and FGF2. These findings indicate that Sulf-1 prevents cartilage degeneration by suppressing MMP-13 via an effect on FGF2/Erk1/2 signalling

MRI Findings of Muscle Damage after Total Hip Arthroplasty Using the Complete Muscle Preserving Anterolateral Supine Approach

Background and Objectives: We performed anterolateral total hip arthroplasty (ALS THA) with the purpose of complete muscle-tendon preservation without muscle-tendon dissection. This study aimed to evaluate muscle damage in the periprosthetic hip joint muscles of patients undergoing ALS THA at 1-year post-operative hip magnetic resonance imaging (MRI). Materials and Methods: We evaluated changes in the muscle cross-sectional area (M-CSA) and fatty atrophy of the periprosthetic muscles. We also assessed the Harris hip score on pre-operative and 12-month post-operative MRI in 66 patients who underwent ALS THA. The grade of M-CSA atrophy was classified into no atrophy, slight atrophy, moderate atrophy, and severe atrophy. Fatty atrophy was classified as improved, no change, and worsened using the Goutallier classification. Results: More than 90% of patients’ M-CSA had no atrophy in the obturator internus (Oi), obturator externus (Oe), gluteus medius (Gmed), and gluteus minimus (Gmin), and some improvement was observed in terms of fatty atrophy. In contrast, M-CSA of the tensor fascia latae (TFL) muscle was clearly decreased, and there was no improvement in the TFL fatty atrophy. However, the presence or absence of TFL atrophy did not affect clinical outcome. Conclusions: We performed the complete muscle preserving procedure, ALS THA, with attention to preserving the Oi and Oe by direct visual confirmation and gentle treatment of the Gmed and Gmin with effective retraction. Post-operative M-CSA atrophy evaluation on MRI showed that the Oi, Oe, Gmed, and Gmin were satisfactorily preserved; however, the TFL was clearly atrophic. In the ALS approach, where entry is made between Gmed and TFL, atrophy of the TFL due to superior gluteal nerve injury must be tolerated to some extent

Synthesis, characterization and its photoluminescence properties of group I-III-VI2 CuInS2 nanocrystals

We report the synthesis, characterization, and photoluminescence (PL) properties of colloidal I-III-VI2 CuInS2 and CuInS2/ZnS nanocrystals (NCs). Absorption shoulder and PL bands of the NCs are located at higher energy than those of band gap energy of bulk crystals due to a quantum-confinement effect. The PL band has a relatively large Stokes-shift, broad linewidth, and long decay-time, which suggests that the PL originates from a recombination of confined-excitions associated with donor(s) and/or acceptor(s). We found that quantum yield of the PL depends strongly on the photon-energy of excitation light and that it is up to 40-50% in resonant excitation at the energy positions corresponding to the absorption shoulder. Detailed properties and possible dynamics will be described. We also present preliminary results of PL properties focused on single NCs. There exist highluminescent NCs exhibiting so-called PL blinking as similar with II-VI NCs, while the others are dark NCs. 73.21.La, 78.47.jd, 78.67.Bf, 78.67.H