Optical properties of the ZnSe nanocrystals embedded in PMMA matrix

In this paper we report linear and nonlinear optical properties of the thin films based on nanocrystals ZnSe embedded in centrosymmetric matrix PMMA, deposited by spin coating technique. Absorption and emission spectroscopy are shown respectively a blue shift and a strong band emission near the band gap of bulk material ZnSe, which is tunable with particles size. Blue shift of the absorption edge used to evaluate the average size of nanoparticles by using the E.M.A model. The size of NCs of ZnSe was estimated to 1.98 nm, compared to the exciton Bohr radius of bulk material. We established a strong quantum confinement state for the NCS ZnSe. Using Nd:YAG laser at 1064 nm in picoseconds regime, Second order susceptibilities were measured by SHG technique. The obtained value was four order of magnitude larger compared with the bulk (ZnSe) value

Linear and nonlinear optical properties of the CdSe nanocrystals embedded in PMMA matrix

CdSe nanocrystals (NCs) were prepared using a colloidal solution and dispersed in polymethylmethacrylate (PMMA) matrix. Using spin coating technique, thin films deposited on glass substrates were prepared. Their structural and optical properties were investigated by X-ray diffraction, atomic force microscopy (AFM) and UV-visible absorption, respectively. The absorption spectra of these dispersed NCs exhibit excitonic peaks resulting from the electron-hole coupling transitions. Due to a quantum confinement effect, a blue shift is deduced by comparison of such transition with respect to reported bulk band gap. Assuming a spherical like shape for these NCs, the crystallites radius (R) was estimated by applying the effective mass approximation model and was about 2.92 nm. Such a weak radius value compared to Bohr radius (RB = 5.5 nm) leads to a strong quantum confinement regime. Moreover, the influence of this confinement effect on nonlinear optical (NLO) properties was also studied. Quadratic and cubic NLO properties were investigated by second and third harmonic generation techniques (SHG and THG) with a Q-switched Nd:YAG laser working at 1064 nm fundamental wavelength. The NLO susceptibilities Χ<2>eff, Χ<3>eff were measured to be equal to 2.27.10-10(m/V) and 2.28.10-20(m2/V2), respectively

Sex differences in the association between plasma copeptin and incident type 2 diabetes: the Prevention of Renal and Vascular Endstage Disease (PREVEND) study

AIMS/HYPOTHESIS: Vasopressin plays a role in osmoregulation, glucose homeostasis and inflammation. Therefore, plasma copeptin, the stable C-terminal portion of the precursor of vasopressin, has strong potential as a biomarker for the cardiometabolic syndrome and diabetes. Previous results were contradictory, which may be explained by differences between men and women in responsiveness of the vasopressin system. The aim of this study was to evaluate the usefulness of copeptin for prediction of future type 2 diabetes in men and women separately. METHODS: From the Prevention of Renal and Vascular Endstage Disease (PREVEND) study, 4,063 women and 3,909 men without diabetes at baseline were included. A total of 208 women and 288 men developed diabetes during a median follow-up of 7.7 years. RESULTS: In multivariable-adjusted models, we observed a stronger association of copeptin with risk of future diabetes in women (OR 1.49 [95% CI 1.24, 1.79]) than in men (OR 1.01 [95% CI 0.85, 1.19]) (p (interaction) < 0.01). The addition of copeptin to the Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR) clinical model improved the discriminative value (C-statistic,+0.007, p = 0.02) and reclassification (integrated discrimination improvement [IDI] = 0.004, p < 0.01) in women. However, we observed no improvement in men. The additive value of copeptin in women was maintained when other independent predictors, such as glucose, high sensitivity C-reactive protein (hs-CRP) and 24 h urinary albumin excretion (UAE), were included in the model. CONCLUSIONS/INTERPRETATION: The association of plasma copeptin with the risk of developing diabetes was stronger in women than in men. Plasma copeptin alone, and along with existing biomarkers (glucose, hs-CRP and UAE), significantly improved the risk prediction for diabetes in women

Towards precise completion of deformable shapes

According to Aristotle, “the whole is greater than the sum of its parts”. This statement was adopted to explain human perception by the Gestalt psychology school of thought in the twentieth century. Here, we claim that when observing a part of an object which was previously acquired as a whole, one could deal with both partial correspondence and shape completion in a holistic manner. More specifically, given the geometry of a full, articulated object in a given pose, as well as a partial scan of the same object in a different pose, we address the new problem of matching the part to the whole while simultaneously reconstructing the new pose from its partial observation. Our approach is data-driven and takes the form of a Siamese autoencoder without the requirement of a consistent vertex labeling at inference time; as such, it can be used on unorganized point clouds as well as on triangle meshes. We demonstrate the practical effectiveness of our model in the applications of single-view deformable shape completion and dense shape correspondence, both on synthetic and real-world geometric data, where we outperform prior work by a large margin

Exploring the Influence of Sr Concentration on the Structural and Catalytic Properties of CuO/SrSO4 Nanocomposites for Organic Dye Degradation

Pure CuO and CuO/SrSO4 nanocomposites were synthesized via the hydrothermal method to explore their catalytic efficacy in degrading methylene blue (MB). CuSO4\ub75H2O, NaOH, and SrCl2\ub76H2O were used as primary reagents. XRD characterization unveiled the monoclinic structure (C2/c) of pure CuO NPs, exhibiting well-defined crystallinity with crystallite sizes ranging from 9.64 to 26.08 nm. Notably, samples with Sr concentrations exceeding 2wt% exhibited a secondary SrSO4 phase with an orthorhombic structure (Pnma). Infrared and Raman spectroscopy confirmed Cu-O, S-O, and Sr-O bond vibrations, validating CuO and SrSO4 synthesis. SEM micrographs depicted irregular platelet-like morphology with a surface area of up to 0.061 μm2 and nanometric thickness for pure CuO NPs, while this morphology varied for CuO/SrSO4 nanocomposites. BET analysis revealed a relatively large specific surface area (9.04 to 15.12 m2 /g), potentially advantageous for catalytic activity. Catalytic degradation of MB in aqueous solution by pure CuO NPs exhibited limited efficiency (19.77% in 60 min), markedly enhanced to 100% in 40 min with the addition of H2O2. Despite H2O2 presence, CuO/SrSO4 nanocomposites showed lower MB degradation efficiency due to sulfate SO4 2- ion poisoning. Monitoring the formation of SrSO4 phase is a synthesis strategy to adjust the poisoning effect by sulfate ions. The sample with a Sr concentration of 6 wt% demonstrated the highest degradation rate (83.78% in 40 min), attributed to its larger specific surface area. Furthermore, synthesized materials displayed satisfactory catalytic stability upon recycling for MB degradation

The impact of neoadjuvant therapy in patients with left-sided resectable pancreatic cancer:an international multicenter study

Background: Left-sided pancreatic cancer is associated with worse overall survival (OS) compared with right-sided pancreatic cancer. Although neoadjuvant therapy is currently seen as not effective in patients with resectable pancreatic cancer (RPC), current randomized trials included mostly patients with right-sided RPC. The purpose of this study was to assess the association between neoadjuvant therapy and OS in patients with left-sided RPC compared with upfront surgery. Patients and methods: This was an international multicenter retrospective study including consecutive patients after left-sided pancreatic resection for pathology-proven RPC, either after neoadjuvant therapy or upfront surgery in 76 centers from 18 countries on 4 continents (2013-2019). The primary endpoint was OS from diagnosis. Time-dependent Cox regression analysis was carried out to investigate the association of neoadjuvant therapy with OS, adjusting for confounders at the time of diagnosis. Adjusted OS probabilities were calculated. Results: Overall, 2282 patients after left-sided pancreatic resection for RPC were included of whom 290 patients (13%) received neoadjuvant therapy. The most common neoadjuvant regimens were (m)FOLFIRINOX (38%) and gemcitabine-nab-paclitaxel (22%). After upfront surgery, 72% of patients received adjuvant chemotherapy, mostly a single-agent regimen (74%). Neoadjuvant therapy was associated with prolonged OS compared with upfront surgery (adjusted hazard ratio 0.69, 95% confidence interval 0.58-0.83) with an adjusted median OS of 53 versus 37 months (P = 0.0003) and adjusted 5-year OS rates of 47% versus 35% (P = 0.0001) compared with upfront surgery. Interaction analysis demonstrated a stronger effect of neoadjuvant therapy in patients with a larger tumor (Pinteraction = 0.003) and higher serum carbohydrate antigen 19-9 (CA19-9; Pinteraction = 0.005). In contrast, the effect of neoadjuvant therapy was not enhanced for splenic artery (Pinteraction = 0.43), splenic vein (Pinteraction = 0.30), retroperitoneal (Pinteraction = 0.84), and multivisceral (Pinteraction = 0.96) involvement. Conclusions: Neoadjuvant therapy in patients with left-sided RPC was associated with improved OS compared with upfront surgery. The impact of neoadjuvant therapy increased with larger tumor size and higher serum CA19-9 at diagnosis. Randomized controlled trials on neoadjuvant therapy specifically in patients with left-sided RPC are needed.</p

Management of patients with hypertension and chronic kidney disease referred to Hypertension Excellence Centres among 27 countries. On behalf of the European Society of Hypertension Working Group on Hypertension and the Kidney.

Objective Real-life management of patients with hypertension and chronic kidney disease (CKD) among European Society of Hypertension Excellence Centres (ESH-ECs) is unclear : we aimed to investigate it. Methods A survey was conducted in 2023. The questionnaire contained 64 questions asking ESH-ECs representatives to estimate how patients with CKD are managed. Results Overall, 88 ESH-ECS representatives from 27 countries participated. According to the responders, renin-angiotensin system (RAS) blockers, calcium-channel blockers and thiazides were often added when these medications were lacking in CKD patients, but physicians were more prone to initiate RAS blockers (90% [interquartile range: 70-95%]) than MRA (20% [10-30%]), SGLT2i (30% [20-50%]) or (GLP1-RA (10% [5-15%]). Despite treatment optimisation, 30% of responders indicated that hypertension remained uncontrolled (30% (15-40%) vs 18% [10%-25%]) in CKD and CKD patients, respectively). Hyperkalemia was the most frequent barrier to initiate RAS blockers, and dosage reduction was considered in 45% of responders when kalaemia was 5.5-5.9 mmol/L. Conclusions RAS blockers are initiated in most ESH-ECS in CKD patients, but MRA and SGLT2i initiations are less frequent. Hyperkalemia was the main barrier for initiation or adequate dosing of RAS blockade, and RAS blockers' dosage reduction was the usual management