423 research outputs found
Mesoporous Titania: Synthesis, Properties and Comparison with Non-Porous Titania
Some relevant physico-chemical and photocatalytic properties of ordered mesoporous TiO2 as obtained by template-assisted synthesis methods are reported. After a review of the crucial aspects related to different synthesis procedures reported by the literature, the focus is pointed on the (often) superior physico-chemical properties of ordered mesoporous TiO2 with respect to (commercial) bulk TiO2. Those are essentially higher specific surface area and ordered mesoporosity; possibility to control the formation of different crystalline phases by varying the synthesis conditions and possibility to obtain films, nanoparticles with different morphologies and/or materials with hierarchical porosity. Although mesoporous TiO2 is extensively studied for many applications in the fields of photocatalysis, energy and biomedicine, this chapter focuses on the use of mesoporous TiO2 in environmental photocatalysis, by putting in evidence how the physico-chemical properties of the material may affect its photocatalytic behaviour and how mesoporous TiO2 behaves in comparison with commercial TiO2 samples
Towards the semi-synthesis of phosphorylated mimics of glycosaminoglycans: Screening of methods for the regioselective phosphorylation of chondroitin
Glycosaminoglycan (GAG) mimics carrying phosphate rather than sulfate anionic groups have been poorly
investigated, in spite of their interesting perspectives. While some GAG-mimicking phosphorylated polymers
have been reported, to the best of our knowledge no phosphorylated polysaccharides having the same backbone
of natural sulfated GAGs have been accessed yet. To fill this gap, in this work two standard phosphorylation
protocols and two recently reported procedures have been screened on a set of polysaccharide species composed
by microbial sourced chondroitin and three partially protected, semi-synthetic derivatives thereof. A detailed
structural characterization by 1H, 13C and 31P NMR spectroscopy revealed the higher versatility of the innovative,
biomimetic reaction employing monopotassium salt of phosphoenolpyruvate (PEP–K) with respect to
standard phosphorylating agents (phosphoric acid or phosphorus oxychloride). Indeed, PEP-K and H3PO4 gave
similar results in the regioselective phosphorylation of the primary hydroxyls of unprotected chondroitin, while
only the former reacted on partially protected chondroitin derivatives in a controlled, regioselective fashion,
affording chondroitin phosphate (CP) polysaccharides with different derivatization patterns. The reported results
represent the first, key steps towards the systematic semi-synthesis of phosphorylated GAGs as a new class of
GAG mimics and to the evaluation of their biological activities in comparison with native sulfated GAGs
Emergency decompressive craniectomy after removal of convexity meningiomas
BACKGROUND: Convexity meningiomas are benign brain tumors that are amenable to complete surgical resection and are associated with a low complication rate. The aim of this study was to identify factors that result in acute postoperative neurological worsening after the removal of convexity meningiomas. METHODS: Clinical evaluation and neuroradiological analysis of patients who underwent removal of a supratentorial convexity meningioma were reviewed. Patients were selected when their postoperative course was complicated by acute neurological deterioration requiring decompressive craniectomy. RESULTS: Six patients (mean age: 43.3 years) underwent surgical removal of a supratentorial convexity meningioma. Brain shift (mean: 9.9 mm) was evident on preoperative imaging due to lesions of varying size and perilesional edema. At various times postoperatively, patient consciousness worsened (up to decerebrate posture) with contralateral paresis and pupillary anisocoria. Computed tomography revealed no postoperative hematoma, however, did indicate increased brain edema and ventricular shift (mean: 12 mm). Emergency decompressive craniectomy and brief ventilator assistance were performed in all patients. Ischemia of the ipsilateral posterior cerebral artery occurred in 3 patients and hydrocephalus occurred in 2 patients. Outcome was good in 2, fair in 2, 1 patient had severe disability, and 1 patient died after 8 months. CONCLUSIONS: Brain shift on preoperative imaging is a substantial risk factor for postoperative neurological worsening in young adult patients after the removal of convexity meningiomas. Emergency decompressive craniectomy must be considered because it is effective in most cases. Other than consciousness impairment, there is no reliable clinical landmark to guide the decision to perform decompressive craniectomy; however, brain ischemia may have already occurred
The Mozart effect in biofeedback visual rehabilitation: a case report
Purpose: To evaluate the usefulness of acoustic biofeedback by means of Mozart's Sonata for Two Pianos in D Major K. 448 to maintain and/or restore visual performance in a patient with macular pucker and glaucoma. Methods: A 74-year-old patient with open angle glaucoma in both eyes and macular pucker in the right eye (RE) underwent visual rehabilitation with acoustic biofeedback by means of the MAIA™ Vision Training Module (Centervue, Padova, Italy) 10 minutes each eye once a week for 5 weeks. The patient was asked to move his eyes according to a sound which changed into Mozart's Sonata for Two Pianos when the patient locked the fixation target. Results: Best-corrected visual acuity improved in his right eye (RE) and was stable in the left eye (LE). Fixation stability improved in both eyes, and retinal sensitivity decreased in the RE and improved in the LE. The characteristic of the macular pucker did not change during the training as demonstrated with optical coherence tomography. The patient was very satisfied with the training, as demonstrated by a 25-item questionnaire (National Eye Institute - Visual Functioning Questionnaire, NEI-VFQ-25). The patient's reading speed and the character size which he was able to read improved in his RE. Conclusion: Music could enhance synaptic plasticity and affect neural learning and fixation training by means of MAIA vision training. Therefore it can improve visual performance in patients with macular pucker, postpone the surgical time, and assure a better quality of life for the patient. © 2011 Salvatore et al
Application of reverse micelle sol-gel synthesis for bulk doping and heteroatoms Surface Enrichment in Mo-Doped TiO 2 nanoparticles
TiO 2 nanoparticles containing 0.0, 1.0, 5.0, and 10.0 wt.% Mo were prepared by a reverse micelle template assisted sol-gel method allowing the dispersion of Mo atoms in the TiO 2 matrix. Their textural and surface properties were characterized by means of X-ray powder diffraction, micro-Raman spectroscopy, N 2 adsorption/desorption isotherms at -196 °C, energy dispersive X-ray analysis coupled to field emission scanning electron microscopy, X-ray photoelectron spectroscopy, diffuse reflectance UV-Vis spectroscopy, and ζ-potential measurement. The photocatalytic degradation of Rhodamine B (under visible light and low irradiance) in water was used as a test reaction as well. The ensemble of the obtained experimental results was analyzed in order to discover the actual state of Mo in the final materials, showing the occurrence of both bulk doping and Mo surface species, with progressive segregation of MoO x species occurring only at a higher Mo content
Effective Inclusion of Sizable Amounts of Mo within TiO2 Nanoparticles Can Be Obtained by Reverse Micelle Sol-Gel Synthesis
Six Mo/TiO2 samples (with 0, 1.0, 2.5, 5.0, 7.5, and 10 wt % Mo nominal contents) were obtained by reverse micelle sol-gel synthesis, followed by calcination at 500 °C. The samples were characterized by means of powder X-ray Diffraction (PXRD), quantitative phase analysis as obtained by Rietveld refinement, field-emission scanning electron microscopy (FE-SEM) coupled with energy-dispersive X-ray analysis, N2 adsorption/desorption at -196 °C, X-ray photoelectron spectroscopy, and diffuse reflectance (DR) UV-vis spectroscopy. As a whole, the adopted characterization techniques showed the inclusion of a sizeable Mo amount, without the segregation of any MoO x phase. Specifically, PXRD showed the occurrence of anatase and brookite with all the studied samples; notwithstanding the mild calcination temperature, the formation of rutile occurred at Mo wt % ≥2.5 likely due to the presence of brookite favoring, in turn, anatase to rutile transition. DR UV-vis and XP spectroscopies allowed determining the samples' band gap energy (E g) and valence band energy, respectively, from which the conduction band energy was calculated; and the observed E g value increase at 10 wt % Mo was ascribed to the Moss-Burstein effect
New retinal imaging for the visualization and analysis of vitreoretinal interface (VRI) by short-wavelength scanning laser ophthalmoscope (swSLO)
Background: The purpose of the study was to evaluate vitreoretinal interface (VRI) alteration with a short-wavelength scanning laser ophthalmoscope (swSLO), the Nidek F-10, and compare the results with those obtained by means of spectral-domain optical coherence tomography (SD-OCT). Methods: Thirty-six eyes were studied (20 patients, mean age 68 ± 12.3 years). All patients underwent a complete ophthalmologic examination, which comprised SD-OCT and Nidek F-10 analysis with short-wavelength blue laser. Eyes were divided into four groups depending on the degree of VRI alteration observed with the swSLO and SD-OCT. Statistical analysis was performed using the Chi-square test. P values less than 0.05 were considered statistically significant. Results: OCT analysis: eight eyes (22%) grade 0 (no abnormalities), 15 eyes (42%) grade 1 (preretinal cellophane); seven (19%) grade 2 (preretinal wrinkling); six (17%) grade 3 (macular pucker or hole). Nidek F-10 analysis: seven (19%) grade 0, 16 (45%) grade 1; seven (19%) grade 2; six (17%) grade 3. Chi-square = 0.099, P = 0.992. There was no statistically significant difference between the two instruments. Conclusion: Nidek F-10 allows both a quantitative and a qualitative evaluation of VRI and is equal to SD-OCT in detecting alteration of the inner portion of the retina, providing an easy way to evaluate and map differences in the inner vitreoretinal surface. © 2011 Vingolo et al, publisher and licensee Dove Medical Press Ltd
Chronic kidney disease and urological disorders: systematic use of uroflowmetry in nephropathic patients
Background. Chronic kidney disease (CKD) is a highly prevalent condition. Urologic disorders are known causes of CKD, but
often remain undiagnosed and underestimated also for their insidious onset and slow progression. We aimed to evaluate
the prevalence of urological unrecognized diseases in CKD patients by uroflowmetry. Methods. We enrolled consecutive stable CKD outpatients. The patients carried out two questionnaires, the International
Prostate Symptom Score and Incontinence Questionnaire-Short Form, and they also underwent uroflowmetry, evaluating
max flow rate (Qmax), voiding time and voided volume values. Results. A total of 83 patients (43 males, mean age of 59.8613.3 years) were enrolled. Our study showed 28 males and 10
females with a significant reduction of Qmax (P<0.001) while 21 females reported a significant increase of Qmax (P<0.001)
with a prevalence of 49.5% of functional urological disease. Moreover, we showed a significant association between Qmax
and creatinine (PÂĽ0.013), estimated glomerular filtration rate (PÂĽ0.029) and voiding volume (PÂĽ0.05). We have not shown
significant associations with age (PÂĽ0.215), body mass index (PÂĽ0.793), systolic blood pressure (PÂĽ0.642) or diastolic blood
pressure (P¼0.305). Moreover, Pearson’s chi-squared test showed a significant association between Qmax altered with CKD
(v2 ÂĽ1.885, PÂĽ0.170) and recurrent infection (v2ÂĽ8.886, PÂĽ0.012), while we have not shown an association with proteinuria
(v2ÂĽ0.484, PÂĽ0.785), diabetes (v2ÂĽ0.334, PÂĽ0.563) or hypertension (v2ÂĽ1.885, PÂĽ0.170).Conclusions. We showed an elevated prevalence of urological diseases in nephropathic patients; therefore, we suggest to
include uroflowmetry in CKD patient assessment, considering the non-invasiveness, repeatability and low cost of
examination. Uroflowmetry could be used to identify previously unrecognized urological diseases, which may prevent the
onset of CKD or progression to end-stage renal disease and reduce the costs of management
Role of Nutrition in Pediatric Patients with Cancer
: Children with cancer are at high risk for developing short-term and long-term nutritional problems related to their underlying disease and side effects of multimodal treatments. Nutritional status (NS) can influence several clinical outcomes, such as overall survival (OS) and event-free survival (EFS), treatment tolerance, risk of developing infections and quality of life (QoL). However, the importance of nutrition in children with cancer is still underestimated. This review focuses on alterations of NS that occurs in children during cancer treatment. In particular, we reviewed the pathogenesis of undernutrition in oncological children, as well as how NS affects treatment tolerance and response, the immune system and the risk of infections of children with cancer. Thanks to recent advances in all types of supportive therapy and to the progress of knowledge on this topic, it has been realized that NS is a modifiable prognostic factor that can be intervened upon to improve the outcome of these patients. Currently, there is a lack of a systematic approach and standard recommendations for nutritional care in the pediatric cancer population. Literature analysis showed that it is essential to define the NS and treat any alterations in a timely manner ensuring proper growth and development. Nutritional follow-up should become an integral part of the care pathway. Regular nutritional monitoring should be performed at diagnosis, during treatment and during follow-up. A close collaboration and sharing of expertise between pediatric oncologists and nutrition specialists, combined with careful and participatory sharing of the feeding experience with the family and the child (after age 6 years), is strongly required
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