113 research outputs found
Supermultiplexed optical imaging and barcoding with engineered polyynes
Optical multiplexing has a large impact in photonics, the life sciences and biomedicine. However, current technology is limited by a 'multiplexing ceiling' from existing optical materials. Here we engineered a class of polyyne-based materials for optical supermultiplexing. We achieved 20 distinct Raman frequencies, as 'Carbon rainbow', through rational engineering of conjugation length, bond-selective isotope doping and end-capping substitution of polyynes. With further probe functionalization, we demonstrated ten-color organelle imaging in individual living cells with high specificity, sensitivity and photostability. Moreover, we realized optical data storage and identification by combinatorial barcoding, yielding to our knowledge the largest number of distinct spectral barcodes to date. Therefore, these polyynes hold great promise in live-cell imaging and sorting as well as in high-throughput diagnostics and screening
Association of insulin resistance, hyperleptinemia, and impaired nitric oxide release with in-stent restenosis in patients undergoing coronary stenting
Previously undiagnosed diabetes, impaired glucose tolerance, and insulin resistance are common in patients with acute myocardial infarction and coronary heart disease (CHD) and might be involved in early restenosis after stent implantation. To evaluate whether markers of insulin resistance syndrome, including leptin, and endothelial dysfunction are related to increased rate of early restenosis, we studied nondiabetic patients with CHD after successful coronary stenting
Thin Layer Chromatography Coupled with Surface-Enhanced Raman Scattering as a Facile Method for On-Site Quantitative Monitoring of Chemical Reactions
Femtosecond Dynamics of the Ring Closing Process of Diarylethene: A Case Study of Electrocyclic Reactions in Photochromic Single Crystals
The cyclization reaction of the photochromic diarylethene derivative 1,2-bis(2,4-dimethyl-5-phenyl-3-thienyl)perfluorocyclopentene was studied in its single crystal phase with femtosecond transient absorption spectroscopy. The transient absorption measurements were performed with a robust acquisition scheme that explicitly exploits the photoreversibility of the molecular system and monitors the reversibility conditions. The crystalline system demonstrated 3 × 104 repeatable cycles before significant degradation was observed. Immediately following photoexcitation, the excited state absorption associated with the open-ring conformation undergoes a large spectral shift with a time constant of approximately 200 fs. Following this evolution on the excited state potential energy surface, the ring closure occurs with a time constant of 5.3 ps, which is significantly slower than previously reported measurements for similar derivatives in the solution phase. Time resolved electron diffraction studies were used to further demonstrate the assignment of the transient absorption dynamics to the ring closing reaction. The mechanistic details of the ring closing are discussed in the context of prior computational work along with a vibrational mode analysis using density functional theory to give some insight into the primary motions involved in the ring closing reaction
Diabete gravemente insulino-resistente associato a tumore desmoide della parete addominale
Una paziente di 51 anni affetta da tumore desmoide della parete addominale ha sviluppato una forma di diabete mellito caratterizzata da una gravissima insulino- resistenza. Il difficile controllo glicemico richiedeva dosi progressivamente crescenti di insulina in infusione endovenosa continua. Gli esami ematochimici escludevano una eziologia autoimmune, mentre la natura acquisita e la modalit\ue0 di insorgenza, insieme con la severit\ue0 del quadro di insulino-resistenza, facevano supporre una origine paraneoplastica della malattia. L\u2019impostazione di un trattamento con un farmaco inibitore di specifiche proteine ad attivit\ue0 tirosin-chinasica sovraespresse nel tessuto neoplastico della paziente ha determinato un significativo miglioramento clinico e il raggiungimento di un soddisfacente controllo glicometabolico mediante terapia insulinica sottocutanea
Prediction of response to recombinant human erythropoietin (rHuEpo) in anemia of malignancy.
BACKGROUND: Since only a portion of anemic patients outside the uremia setting benefit from erythropoietin treatment, a reliable means of predicting potential responders and nonresponders would be very useful. MATERIALS AND METHODS: We retrospectively reviewed the clinical records of 58 patients with refractory anemia associated with various malignant disorders who had been treated with subcutaneous rHuEpo. The starting rHuEpo dose was 375 U/kg/week for 4 weeks, and was increased to 750 U/kg/week for another 4 weeks if no response was observed. Response was defined as a Hb increase > or = 2 g/dL with no need for blood transfusion. We examined the value of various laboratory parameters (baseline levels, 2-week and 4-week changes) as predictors of response. Endogenous erythropoietin production was evaluated by its serum level and erythroid activity was assessed through reticulocyte count and circulating transferrin receptor. RESULTS: Forty-eight individuals were evaluable, 58% of whom responded to rHuEpo within 8 weeks. Multiple regression analysis showed that 53% of the variation in the 8-week Hb concentration was explained by variations in baseline serum erythropoietin and the 2-week change in serum transferrin receptor (p < 0.001). Based on these two parameters, response prediction in individual patients would have resulted in a sensitivity of 96%, a specificity of 79% and an overall accuracy of 88%. In addition, 58% of the variation in the 8-week Hb was explained by variations in the 4-week changes in Hb and reticulocyte count (p < 0.001). Utilizing these latter parameters and baseline serum erythropoietin, response prediction in individual patients would have resulted in a sensitivity of 92%, a specificity of 82% and an overall accuracy of 88%. CONCLUSIONS: This retrospective analysis suggests that response to rHuEpo can be reasonably predicted by pretreatment serum erythropoietin together with early changes in simple laboratory parameters
Cannonite [Bi2O(SO4)(OH)2] from Alfenza (Crodo, Italy): Crystal structure and morphology
Canonite from Alfenza grows as crowded, radiating, acicular aggregates covering bismuthinite
crystals. Individual crystals have a lozenge-shaped habit on {010}, the presumed cleavage plane of
cannonite. Crystal structure refinements in the P21/c space group of two single crystals led to the
following cell parameters: a = 7.7196(5) A ˚ , b = 13.8856(9), c = 5.6980(4), b = 109.174(1)º (R1 =
0.0424); and a = 7.7100(8), b = 13.8717(14), c = 5.6939(6), b = 109.155(2)º (R1 = 0.0438). Hydrogen
atoms were also localized in the density-difference Fourier map and refined with soft restraints on the
bond distances. Raman and IR spectroscopy confirm the presence of OH groups and the absence of
molecular water, and deliver OH···O geometry wholly comparable with the structure refinement.
Electron microprobe analyses revealed no significant levels of elements other than those expected in
the ideal formula except fluorine which was present up to 0.14 a.p.f.u. The crystal structure can be
described in terms of anion-centred OBi4 edge-sharing tetrahedra forming chains running parallel to z
and strongly cemented along x by isolated SO4 tetrahedra. Each OBi4 tetrahedron is further connected
along y by OH groups, making walls of composition Bi4O2(SO4)2(OH)4 parallel to (010). These walls
are tied to each other along y by fewer Bi–O–S bridges and weaker OH···O bonds
Self-Assembled Monolayers Assisted all Wet Metallization of SU-8 Negative Tone Photoresist
The present work investigates the application of a Self-Assembled Monolayer (SAM) on the widely used negative photoresist SU-8. (3-Aminopropyl) trimethoxysilane (APTMS) is employed to form SAMs on the surface of the polymer through wet silanization in ethanol. The treatment process of SU-8 resin surface is optimized to achieve a well-formed, high quality SAM. Wettability measurements, atomic force microscopy (AFM) and infrared (IR) spectroscopy are employed to follow and optimize the silanization process. Following silanization, the resulting SAMs are employed as adhesion layers for electroless plated metallic layers. For this purpose, the superior affinity of APTMS amine terminal groups towards Pd2+ ions is exploited to activate the surface. Metallic coatings such as Cu, Ni-P or Co-Ni-P are thus deposited by mean of autocatalytic deposition. The surface of metallized samples is analyzed using AFM, scanning electron microscopy (SEM) and glow discharge optical emission spectroscopy (GDOES). Finally, Ni-P is deposited on a micropatterned SU-8 surface to demonstrate the potential of the presented metallization approach for microfabrication
- …