115 research outputs found
Comparison of Ten Metal-Doped LaFeO3 Samples on Photocatalytic Degradation of Antibiotics in Water under Visible Light: Role of Surface Area and Aqueous Phosphate Ions
Doping semiconducting oxides, such as LaFeO3 (LF), with metallic elements is a good strategy to improve the performance of photocatalysts. In this study, LF and ten different nanopowders metal-doped at the La or Fe site of LaFeO3 were evaluated in the photocatalytic degradation of ciprofloxacin (CP) and oxytetracycline (OTC). The following metals were used in the doping (mol%) process of LF: Pd 3% and 5%; Cu 10%; Mg 5%, 10%, and 20%; Ga 10%; Y 10% and 20%; and Sr 20%. The doped samples were synthetized using a citrate auto-combustion technique. From the X-ray diffraction (XRD) data, only a single crystalline phase, namely an orthorhombic perovskite structure, was observed except for trace amounts of PdO in the sample with Pd 5%. The specific surface area (SSA) ranged from 9 m(2) g(-1) (Ga 10%) to 20 m(2) g(-1) (Mg 20%). SEM images show that all samples were constituted from agglomerates of particles whose sizes ranged from ca. 20 nm (Mg 20%) to ca. 100 nm (Pd 5%). Dilute aqueous solutions (5 x 10(-6) M) prepared for both CP and OTC were irradiated for 240 min under visible-light and in the presence of H2O2 (10(-2) M). The results indicate a 78% removal of OTC with Cu 10% doped LF in a phosphate buffer (pH = 5.0). The degradation of CP is affected by pH and phosphate ions, with 78% (in unbuffered solution) and 54% (in phosphate buffer, pH = 5.0) removal achieved with Mg 10% doped LF. The reactions follow a pseudo-first order kinetic. Overall, this study is expected to deepen the assessment of photocatalytic activity by using substrates with different absorption capacities on photocatalysts
Experimental and calculated circular dichroism spectra of monoaza[5]helicenes
Circular dichroism (CD) spectra have been measured in the range of 400–200 nm on CH3OH solutions of both enantiomers for the
almost complete series of monoaza[5]helicenes, namely the molecules where the hetero N atom occupies positions 1, 3, 4, 5, 6, and 7,
respectively (the 2 isomer is missing due to difficulties in the synthesis). CD spectra recorded at controlled room temperature allow
one to define precise racemization rates, that are nicely interpreted on the basis of DFT molecular orbital calculations. Time-dependent
DFT methods provide us with calculated CD and UV spectra, that are compared with the corresponding experimental data. We discuss
the role of the N atom in determining the height of the racemization barrier and in shaping the appearance of the CD spectra
Clinical autonomic nervous system laboratories in Europe. A joint survey of the European Academy of Neurology and the European Federation of Autonomic Societies
Background and purpose: Disorders of the autonomic nervous system (ANS) are common conditions, but it is unclear whether access to ANS healthcare provision is homogeneous across European countries. The aim of this study was to identify neurology-driven or interdisciplinary clinical ANS laboratories in Europe, describe their characteristics and explore regional differences. Methods: We contacted the European national ANS and neurological societies, as well as members of our professional network, to identify clinical ANS laboratories in each country and invite them to answer a web-based survey. Results: We identified 84 laboratories in 22 countries and 46 (55%) answered the survey. All laboratories perform cardiovascular autonomic function tests, and 83% also perform sweat tests. Testing for catecholamines and autoantibodies are performed in 63% and 56% of laboratories, and epidermal nerve fiber density analysis in 63%. Each laboratory is staffed by a median of two consultants, one resident, one technician and one nurse. The median (interquartile range [IQR]) number of head-up tilt tests/laboratory/year is 105 (49–251). Reflex syncope and neurogenic orthostatic hypotension are the most frequently diagnosed cardiovascular ANS disorders. Thirty-five centers (76%) have an ANS outpatient clinic, with a median (IQR) of 200 (100–360) outpatient visits/year; 42 centers (91%) also offer inpatient care (median 20 [IQR 4–110] inpatient stays/year). Forty-one laboratories (89%) are involved in research activities. We observed a significant difference in the geographical distribution of ANS services among European regions: 11 out of 12 countries from North/West Europe have at least one ANS laboratory versus 11 out of 21 from South/East/Greater Europe (p = 0.021). Conclusions: This survey highlights disparities in the availability of healthcare services for people with ANS disorders across European countries, stressing the need for improved access to specialized care in South, East and Greater Europe
Consensus protocol for EEG and amplitude-integrated EEG assessment and monitoring in neonates
The aim of this work is to establish inclusive guidelines on electroencephalography (EEG) applicable to all neonatal intensive care units (NICUs). Guidelines on ideal EEG monitoring for neonates are available, but there are significant barriers to their implementation in many centres around the world. These include barriers due to limited resources regarding the availability of equipment and technical and interpretive round-the-clock personnel. On the other hand, despite its limitations, amplitude-integrated EEG (aEEG) (previously called Cerebral Function Monitor [CFM]) is a common alternative used in NICUs. The Italian Neonatal Seizure Collaborative Network (INNESCO), working with all national scientific societies interested in the field of neonatal clinical neurophysiology, performed a systematic literature review and promoted interdisciplinary discussions among experts (neonatologists, paediatric neurologists, neurophysiologists, technicians) between 2017 and 2020 with the aim of elaborating shared recommendations. A consensus statement on videoEEG (vEEG) and aEEG for the principal neonatal indications was established. The authors propose a flexible frame of recommendations based on the complementary use of vEEG and aEEG applicable to the various neonatal units with different levels of complexity according to local resources and specific patient features. Suggestions for promoting cooperation between neonatologists, paediatric neurologists, and neurophysiologists, organisational restructuring, and teleneurophysiology implementation are provided
Chemistry and microstructure of cement pastes admixed with organic liquids
The influence of organic admixtures on hydration process of cement pastes have been investigated to assess the possibility of immobilizing toxic organic wastes in cement-based materials. The model organic waste used is a mixture of water, methanol and 2-chloroaniline: 100/76/4 volume ratios, respectively. Four pastes were obtained admixing this solution with two different cements (ordinary and white Portland), with weight ratios equal to 0.40 and 0.65, respectively; in addition, cement pastes without organic wastes were prepared (water to cement ratio 0.40). The progress of hydration process of these six series of samples was monitored for the first 8 months of ageing by thermogravimetric analysis; moreover, a detailed microstructural investigation on mature pastes was performed by quantitative X-ray diffraction and scanning electron microscopy. Dynamic leach tests were carried out on samples cured for 28 days, according to the international standards
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