Does Alumina Coating Alter the Solid Permeable Interphase Dynamics in LiMn2O4 Cathodes?

It is well known that the Al2O3 coating of the LiMn2O4 cathodes leads to improvement of the performance of these electrodes. However, the effect of the coating on the fundamental processes occurring on the interface with the active material which results in the formation of the solid permeable interphase is yet to be investigated. These effects should be more pronounced in the first cycle when a dynamic interaction of the active material at high voltage with the electrolyte and binder leads to the formation of this passivation layer. Here, we present a detailed investigation of the solid permeable interphase formation in alumina-coated and uncoated LiMn2O4 electrodes using X-ray absorption spectroscopy and analysis on the electrodes at the predesigned charging/ discharging states. We demonstrate that the alumina coating leads to modification of the solid permeable layer and its dynamics. We also discuss the possible influences of interface modifications via coating on the battery performance

3D printed multi-compartment capsular devices for two-pulse oral drug delivery

In the drug delivery area, versatile therapeutic systems intended to yield customized combinations of drugs, drug doses and release kinetics have drawn increasing attention, especially because of the advantages that personalized pharmaceutical treatments would offer. In this respect, a previously proposed capsular device able to control the release performance based on its design and composition, which could extemporaneously be filled, was improved to include multiple separate compartments so that differing active ingredients or formulations may be conveyed. The compartments, which may differ in thickness and composition, resulted from assembly of two hollow halves through a joint also acting as a partition. The systems were manufactured by fused deposition modeling (FDM) 3D printing, which holds special potential for product personalization, and injection molding (IM) that would enable production on a larger scale. Through combination of compartments having wall thickness of 600 or 1200\u3bcm, composed of promptly soluble, swellable/erodible or enteric soluble polymers, devices showing two-pulse release patterns, consistent with the nature of the starting materials, were obtained. Systems fabricated using the two techniques exhibited comparable performance, thus proving the prototyping ability of FDM versus IM

The perceived ability of gastroenterologists, hepatologists and surgeons can bias medical decision making

Medical errors are a troubling issue and physicians should be careful to scrutinize their own decisions, remaining open to the possibility that they may be wrong. Even so, doctors may still be overconfident. A survey was here conducted to test how medical experience and self-confidence can affect physicians working in the specific clinical area. Potential participants were contacted through personalized emails and invited to contribute to the survey. The \u201crisk-intelligence\u201d test consists of 50 statements about general knowledge in which participants were asked to indicate how likely they thought that each statement was true or false. The risk-intelligence quotient (RQ), a measure of self-confidence, varies between 0 and 100. The higher the RQ score, the better the confidence in personal knowledge. To allow for a representation of 1000 physicians, the sample size was calculated as 278 respondents. A total of 1334 individual emails were sent to reach 278 respondents. A control group of 198 medical students were also invited, of them, 54 responded to the survey. The mean RQ (SD)of physicians was 61.1 (11.4) and that of students was 52.6 (9.9). Assuming age as indicator of knowledge, it was observed that physicians 6434 years had a mean RQ of 59.1 (10.1); those of 35\u201342 years had 61.0 (11.0); in those of 43\u201351 years increased to 62.9 (12.2); reached a plateau of 63.0 (11.5) between 52\u201359 years and decreased to 59.6 (12.1) in respondents 6560 years (r2:0.992). Doctors overestimate smaller probabilities and under-estimate higher probabilities. Specialists in gastroenterology and hepato-biliary diseases suffer from some degree of self-confidence bias, potentially leading to medical errors. Approaches aimed at ameliorating the self-judgment should be promoted more widely in medical education

Mechanically induced cis-to-trans isomerization of carbon–carbon double bonds using atomic force microscopy

Cis-to-trans isomerization of carbon–carbon double bonds can be induced by the application of mechanical force. Using single molecule force spectroscopy by means of atomic force microscopy (AFM) we pulled polymer molecules which contained cis double bonds in the backbone. In the force versus extension profiles of these polymers, a sudden extension increase is observed which is due to the conversion of shorter cis isomers into longer trans isomers. The added length to the polymer results in relaxation in probed force. We find that the isomerization occurs at forces of 800 ± 60 pN, independent of AFM tip and solid substrate chemistries. Investigation of similar polymers which exclusively contained single bonds in the backbone showed no evidence of a similar transition

Retentive device for intravesical drug delivery based on water-induced shape memory response of poly(vinyl alcohol): design concept and 4D printing feasibility

The use of shape memory polymers exhibiting water-induced shape recovery at body temperature and water solubility was proposed for the development of indwelling devices for intravesical drug delivery. These could be administered via catheter in a suitable temporary shape, retained in the bladder for a programmed period of time by recovery of the original shape and eliminated with urine following dissolution/erosion. Hot melt extrusion and fused deposition modeling 3D printing were employed as the manufacturing techniques, the latter resulting in 4D printing because of the shape modifications undergone by the printed item over time. Pharmaceutical-grade poly(vinyl alcohol) was selected based on its hot-processability, availability in different molecular weights and on preliminary data showing water-induced shape memory behavior. Specimens having various original and temporary geometries as well as compositions, successfully obtained, were characterized by differential scanning calorimetry and dynamic-mechanical thermal analysis as well as for fluid uptake, mass loss, shape recovery and release behavior. The samples exhibited the desired ability to recover the original shape, consistent in kinetics with the relevant thermo-mechanical properties, and concomitant prolonged release of a tracer. Although preliminary in scope, this study indicated the viability of the proposed approach to the design of retentive intravesical delivery systems

Microenvironment stimuli HGF and hypoxia differently affected miR-125b and Ets-1 function with opposite effects on the invasiveness of bone metastatic cells : A comparison with breast carcinoma cells

We examined the influence of microenvironment stimuli on molecular events relevant to the biological functions of 1833-bone metastatic clone and the parental MDA-MB231 cells. (i) In both the cell lines, hepatocyte growth factor (HGF) and the osteoblasts\u2019 biological products down regulated nuclear Ets-1-protein level in concomitance with endogenous miR-125b accumulation. In contrast, under hypoxia nuclear Ets-1 was unchanged, notwithstanding the miR-125b increase. (ii) Also, the 1833-cell invasiveness and the expression of Endothelin-1, the target gene of Ets-1/HIF-1, showed opposite patterns under HGF and hypoxia. We clarified the molecular mechanism(s) reproducing the high miR-125b levels with the mimic in 1833 cells. Under hypoxia, the miR-125b mimic maintained a basal level and functional Ets-1 protein, as testified by the elevated cell invasiveness. However, under HGF ectopic miR-125b downregulated Ets-1 protein and cell motility, likely involving an Ets-1-dominant negative form sensible to serum conditions; Ets-1-activity inhibition by HGF implicated HIF-1\u3b1 accumulation, which drugged Ets-1 in the complex bound to the Endothelin-1 promoter. Altogether, 1833-cell exposure to HGF would decrease Endothelin-1 transactivation and protein expression, with the possible impairment of Endothelin-1-dependent induction of E-cadherin, and the reversion towards an invasive phenotype: this was favoured by Ets-1 overexpression, which inhibited HIF-1\u3b1 expression and HIF-1 activity. (iii) In MDA-MB231 cells, HGF strongly and rapidly decreased Ets-1, hampering invasiveness and reducing Ets-1-binding to Endothelin-1 promoter; HIF-1\u3b1 did not form a complex with Ets-1 and Endothelin-1-luciferase activity was unchanged. Overall, depending on the microenvironment conditions and endogenous miR-125b levels, bone-metastatic cells might switch from Ets-1-dependent motility towards colonization/growth, regulated by the balance between Ets-1 and HIF-1

Central factorials under the Kontorovich-Lebedev transform of polynomials

We show that slight modifications of the Kontorovich-Lebedev transform lead to an automorphism of the vector space of polynomials. This circumstance along with the Mellin transformation property of the modified Bessel functions perform the passage of monomials to central factorial polynomials. A special attention is driven to the polynomial sequences whose KL-transform is the canonical sequence, which will be fully characterized. Finally, new identities between the central factorials and the Euler polynomials are found.Comment: also available at http://cmup.fc.up.pt/cmup/ since the 2nd August 201

Highly stable Fe3O4/C composite: a candidate material for all solid-state lithium-ion batteries

Fe3O4 nanoparticles synthesized by a base catalyzed method are tested in an All-Solid-State (ASLB) battery using a sulfide electrolyte. The pristine nanoparticles were morphologically characterized showing an average size of 12 nm. The evaluation of the electrochemical properties shows high specific capacity values of 506 mAhg−1 after 350 cycles at a specific current of 250 mAg−1, with very high stability and coulombic efficiency