PTFE-Doped CeO2 Films: Synthesis, Characterization and Properties

Multi-functional hybrid films were developed by doping PTFE into CeO2 by co-sputtering of CeO2 and PTFE targets. The hybrid films formed on borosilicate glass substrate containing from 5 to 15 vol. % PTFE in CeO2 showed UV shielding, high indentation hardness, hydrophobicity, optical transmittance in visible light, and high bending crack resistance. Optical properties of 100 nm thick CeO2 -5 vol. % PTFE film revealed UV light shielding of more than 80 % at 380 nm and visible light transmittance higher than 80 %. Indentation hardness measured under the load of 0.001mN was more than 16,000N/mm2 of 2.7 times higher than the glass substrate. No crack in the film was observed by bending 1.5 cm in diameter. Furthermore, the hydrophobic surface property was evaluated by the water contact angle to be higher than 90 degrees. Preliminary characterization of the CeO2-PTFE film using XPS and XMA revealed that chemical states of F in sputter doped PTFE in CeO2 can be considered to exist as C-F and Ce-F compounds. On the other hand, chemical states of Ce changed partially from Ce+4 (CeO2) to Ce+3 (Ce2O3 or CeF3) with increasing doped PTFEF in the film.In this rapid communication, we preliminary described the optical, mechanical and chemical properties of newly developed hybrid CeO2-PTFE films prepared by sputtering

Sinorhizobium Meliloti, A Bacterium Lacking The Autoinducer-2 (AI-2) Synthase, Responds To AI-2 Supplied By Other Bacteria

Many bacterial species respond to the quorum-sensing signal autoinducer-2 (AI-2) by regulating different niche-specific genes. Here, we show that Sinorhizobium meliloti, a plant symbiont lacking the gene for the AI-2 synthase, while not capable of producing AI-2 can nonetheless respond to AI-2 produced by other species. We demonstrate that S. meliloti has a periplasmic binding protein that binds AI-2. The crystal structure of this protein (here named SmlsrB) with its ligand reveals that it binds (2R,4S)-2-methyl-2,3,3,4-tetrahydroxytetrahydrofuran (R-THMF), the identical AI-2 isomer recognized by LsrB of Salmonella typhimurium. The gene encoding SmlsrB is in an operon with orthologues of the lsr genes required for AI-2 internalization in enteric bacteria. Accordingly, S. meliloti internalizes exogenous AI-2, and mutants in this operon are defective in AI-2 internalization. S. meliloti does not gain a metabolic benefit from internalizing AI-2, suggesting that AI-2 functions as a signal in S. meliloti. Furthermore, S. meliloti can completely eliminate the AI-2 secreted by Erwinia carotovora, a plant pathogen shown to use AI-2 to regulate virulence. Our findings suggest that S. meliloti is capable of \u27eavesdropping\u27 on the AI-2 signalling of other species and interfering with AI-2-regulated behaviours such as virulence

Lepton-Flavour Violation in Ordinary and Supersymmetric Grand Unified Theories

By an explicit calculation we show that in ordinary SU(5) logarithmic divergence in the amplitude of $\mu \to e\gamma$ cancels among diagrams and remaining finite part is suppressed by at least $1/M_{GUT}^2$. In SUSY SU(5), when the effect of flavour changing wave function renormalization is taken into account such logarithmic correction disappears, provided a condition is met among SUSY breaking masses. In SUGRA-inspired SUSY GUT the remaining logarithmic effect is argued not to be taken as a prediction of the theory.Comment: 8 pages, LaTeX209 file, using axodraw.st

The importance of early arthroscopy in athletes with painful cartilage lesions of the ankle: a prospective study of 61 consecutive cases

BACKGROUND Ankle sprains are common in sports and can sometimes result in a persistent pain condition. PURPOSE Primarily to evaluate clinical symptoms, signs, diagnostics and outcomes of surgery for symptomatic chondral injuries of the talo crural joint in athletes. Secondly, in applicable cases, to evaluate the accuracy of MRI in detecting these injuries. Type of study: Prospective consecutive series. METHODS Over around 4 years we studied 61 consecutive athletes with symptomatic chondral lesions to the talocrural joint causing persistent exertion ankle pain. RESULTS 43% were professional full time athletes and 67% were semi-professional, elite or amateur athletes, main sports being soccer (49%) and rugby (14%). The main subjective complaint was exertion ankle pain (93%). Effusion (75%) and joint line tenderness on palpation (92%) were the most common clinical findings. The duration from injury to arthroscopy for 58/61 cases was 7 months (5.7–7.9). 3/61 cases were referred within 3 weeks from injury. There were in total 75 cartilage lesions. Of these, 52 were located on the Talus dome, 17 on the medial malleolus and 6 on the Tibia plafond. Of the Talus dome injuries 18 were anteromedial, 14 anterolateral, 9 posteromedial, 3 posterolateral and 8 affecting mid talus. 50% were grade 4 lesions, 13.3% grade 3, 16.7% grade 2 and 20% grade 1. MRI had been performed pre operatively in 26/61 (39%) and 59% of these had been interpreted as normal. Detection rate of cartilage lesions was only 19%, but subchondral oedema was present in 55%. At clinical follow up average 24 months after surgery (10–48 months), 73% were playing at pre-injury level. The average return to that level of sports after surgery was 16 weeks (3–32 weeks). However 43% still suffered minor symptoms. CONCLUSION Arthroscopy should be considered early when an athlete presents with exertion ankle pain, effusion and joint line tenderness on palpation after a previous sprain. Conventional MRI is not reliable for detecting isolated cartilage lesions, but the presence of subchondral oedema should raise such suspicion

A niche-mimicking polymer hydrogel-based approach to identify molecular targets for tackling human pancreatic cancer stem cells.

BACKGROUND: Pancreatic adenocarcinoma (PAAD) is one of the most fatal human cancers, but effective therapies remain to be established. Cancer stem cells (CSCs) are highly resistant to anti-cancer drugs and a deeper understanding of their microenvironmental niche has been considered important to provide understanding and solutions to cancer eradication. However, as the CSC niche is composed of a wide variety of biological and physicochemical factors, the development of multidisciplinary tools that recapitulate their complex features is indispensable. Synthetic polymers have been studied as attractive biomaterials due to their tunable biofunctionalities, while hydrogelation technique further renders upon them a diversity of physical properties, making them an attractive tool for analysis of the CSC niche. METHODS: To develop innovative materials that recapitulate the CSC niche in pancreatic cancers, we performed polymer microarray analysis to identify niche-mimicking scaffolds that preferentially supported the growth of CSCs. The niche-mimicking activity of the identified polymers was further optimized by polyethylene glycol (PEG)-based hydrogelation. To reveal the biological mechanisms behind the activity of the optimized hydrogels towards CSCs, proteins binding onto the hydrogel were analyzed by liquid chromatography with tandem mass spectrometry (LC-MS/MS), and the potential therapeutic targets were validated by looking at gene expression and patients' outcome in the TCGA database. RESULTS: PA531, a heteropolymer composed of 2-methoxyethyl methacrylate (MEMA) and 2-(diethylamino)ethyl methacrylate (DEAEMA) (5.5:4.5) that specifically supports the growth and maintenance of CSCs was identified by polymer microarray screening using the human PAAD cell line KLM1. The polymer PA531 was converted into five hydrogels (PA531-HG1 to HG5) and developed to give an optimized scaffold with the highest CSC niche-mimicking activities. From this polymer that recapitulated CSC binding and control, the proteins fetuin-B and angiotensinogen were identified as candidate target molecules with clinical significance due to the correlation between gene expression levels and prognosis in PAAD patients and the proteins associated with the niche-mimicking polymer. CONCLUSION: This study screened for biofunctional polymers suitable for recapitulation of the pancreatic CSC niche and one hydrogel with high niche-mimicking abilities was successfully fabricated. Two soluble factors with clinical significance were identified as potential candidates for biomarkers and therapeutic targets in pancreatic cancers. Such a biomaterial-based approach could be a new platform in drug discovery and therapy development against CSCs, via targeting of their niche

Evolution of central pattern generators for the control of a five-link bipedal walking mechanism

Central pattern generators (CPGs), with a basis is neurophysiological studies, are a type of neural network for the generation of rhythmic motion. While CPGs are being increasingly used in robot control, most applications are hand-tuned for a specific task and it is acknowledged in the field that generic methods and design principles for creating individual networks for a given task are lacking. This study presents an approach where the connectivity and oscillatory parameters of a CPG network are determined by an evolutionary algorithm with fitness evaluations in a realistic simulation with accurate physics. We apply this technique to a five-link planar walking mechanism to demonstrate its feasibility and performance. In addition, to see whether results from simulation can be acceptably transferred to real robot hardware, the best evolved CPG network is also tested on a real mechanism. Our results also confirm that the biologically inspired CPG model is well suited for legged locomotion, since a diverse manifestation of networks have been observed to succeed in fitness simulations during evolution.Comment: 11 pages, 9 figures; substantial revision of content, organization, and quantitative result

Role of the Small GTPase Rho3 in Golgi/Endosome Trafficking through Functional Interaction with Adaptin in Fission Yeast

BACKGROUND: We had previously identified the mutant allele of apm1(+) that encodes a homolog of the mammalian µ1A subunit of the clathrin-associated adaptor protein-1 (AP-1) complex, and we demonstrated the role of Apm1 in Golgi/endosome trafficking, secretion, and vacuole fusion in fission yeast. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we isolated rho3(+), which encodes a Rho-family small GTPase, an important regulator of exocystosis, as a multicopy-suppressor of the temperature-sensitive growth of the apm1-1 mutant cells. Overexpression of Rho3 suppressed the Cl(-) sensitivity and immunosuppressant sensitivity of the apm1-1 mutant cells. Overexpression of Rho3 also suppressed the fragmentation of vacuoles, and the accumulation of v-SNARE Syb1 in Golgi/endosomes and partially suppressed the defective secretion associated with apm1-deletion cells. Notably, electron microscopic observation of the rho3-deletion cells revealed the accumulation of abnormal Golgi-like structures, vacuole fragmentation, and accumulation of secretory vesicles; these phenotypes were very similar to those of the apm1-deletion cells. Furthermore, the rho3-deletion cells and apm1-deletion cells showed very similar phenotypic characteristics, including the sensitivity to the immunosuppressant FK506, the cell wall-damaging agent micafungin, Cl(-), and valproic acid. Green fluorescent protein (GFP)-Rho3 was localized at Golgi/endosomes as well as the plasma membrane and division site. Finally, Rho3 was shown to form a complex with Apm1 as well as with other subunits of the clathrin-associated AP-1 complex in a GTP- and effector domain-dependent manner. CONCLUSIONS/SIGNIFICANCE: Taken together, our findings reveal a novel role of Rho3 in the regulation of Golgi/endosome trafficking and suggest that clathrin-associated adaptor protein-1 and Rho3 co-ordinate in intracellular transport in fission yeast. To the best of our knowledge, this study provides the first evidence of a direct link between the small GTPase Rho and the clathrin-associated adaptor protein-1 in membrane trafficking

Raman Scattering Study of Ba-doped C60 with t1g States

Raman spectra are reported for Ba doped fullerides, BaxC60(x=3,4,and 6). The lowest frequency Hg modes split into five components for Ba4C60 and Ba6C60 even at room temperature, allowing us a quantitative analysis based on the electron-phonon couping theory. For the superconducting Ba4C60, the density of states at the Fermi energy was derived as 7 eV-1, while the total value of electron-phonon coupling \lambda was found to be 1.0, which is comparable to that of K3C60. The tangential Ag(2) mode, which is known as a sensitive probe for the degree of charge transfer on C60 molecule, shows a remarkable shift depending on the Ba concentration, being roughly consistent with the full charge transfer from Ba to C60. An effect of hybridization between Ba and C60 \pi orbitals is also discussed.Comment: 15 pages, 6 figures submitted to Phys. Rev. B (December 1,1998

Molecular Gas in NUclei of GAlaxies (NUGA) I.The counter-rotating LINER NGC4826

We present new high-resolution observations of the nucleus of the counter-rotating LINER NGC4826, made in the J=1-0 and J=2-1 lines of 12CO with the IRAM Plateau de Bure mm-interferometer(PdBI).The CO maps, which achieve 0.8''(16pc) resolution in the 2-1 line, fully resolve an inner molecular gas disk which is truncated at an outer radius of 700pc. The total molecular gas mass is distributed in a lopsided nuclear disk of 40pc radius and two one-arm spirals, which develop at different radii in the disk. The distribution and kinematics of molecular gas in the inner 1kpc of NGC4826 show the prevalence of different types of m=1 perturbations in the gas. Although dominated by rotation, the gas kinematics are perturbed by streaming motions related to the m=1 instabilities. The non-circular motions associated with the inner m=1 perturbations agree qualitatively with the pattern expected for a trailing wave developed outside corotation ('fast' wave). In contrast, the streaming motions in the outer m=1 spiral are better explained by a 'slow' wave. A paradoxical consequence is that the inner m=1 perturbations would not favour AGN feeding. An independent confirmation that the AGN is not being generously fueled at present is found in the low values of the gravitational torques exerted by the stellar potential for R<530pc. The distribution of star formation in the disk of NGC4826 is also strongly asymmetrical. Massive star formation is still vigorous, fed by the significant molecular gas reservoir at R<700pc. There is supporting evidence for a recent large mass inflow episode in NGC4826. These observations have been made in the context of the NUclei of GAlaxies (NUGA) project, aimed at the study of the different mechanisms for gas fueling of AGN.Comment: A&A, 2003, Paper accepted (04/06/03). For a full-resolution version of this paper see http://www.oan.es/preprint