229 research outputs found
New TiO2 based photocatalysts for the degradation of organic pollutants in water
No full textIn the last years a new category of TiO2 based composites prepared by impregnation of bare polycrystalline TiO2 powders with different sensitizers (i.e. phthalocyanines, porphyrins) permitted the improvement of the photocatalytic degradation of 4-nitrophenol (4-NP) under UV1-3 as well as under visible light irradiation.4 On the other hand growing interest devoted to the photodegradation of organic pollutants in water solutions by means of economically advantageous and environmental friendly processes are regarding this topic.
Continuing our research in this area, we report here our recent results concerning: i) the preparation of new TiO2 and TiO2 based photocatalysts containing Fe and Cu species; ii) improvement of the photodegradation processes and conditions.
1. Mele, G.; Del Sole, R.; Vasapollo, G.; García-López, E.; Palmisano, L.; Schiavello, M. J. Catal. 2003, 217, 334. 2. Mele, G. ; Del Sole, R.; Vasapollo, G.; Marcì, G.; Garcìa-Lòpez, E.; Palmisano, L.; Coronado, J. M.; Hernández-Alonso, M. D.; Malitesta, C.; Guascito, R. J. Phys Chem. B 2005, 109, 12347. 3. Mele, G.; García-López, E.; Palmisano, L.; Dyrda, G.; Słota, R. J. Phys. Chem. C, 2007, 111, 6581. 4. Wang, C.; Li, J.; Mele, G.; Yang, G. M.; Zhang, F. X.; Palmisano, L.; Vasapollo, G. Appl. Catal. B: Environ. 2007, 76, 218
Use of formic or oxalic acid for the regioselective hydrocarboxylation of alkenes and alkynes catalyzed by palladium/carbon and 1,4-bis(diphenylphosphino)butane
No full textAlkenes and alkynes react with carbon monoxide and either formic acid or oxalic acid catalyzed by Pd/C and 1,4-bis(diphenylphosphino)butane, affording straight chain carboxylic acids in good regioselectivity
Hemodynamic guided treatment of hypertensive disorders in pregnancy: is it time to change our mind?
No full textSARS-CoV-2, Endothelial Dysfunction, and the Renin-Angiotensin System (RAS): A Potentially Dangerous Triad for the Development of Pre-Eclampsia
No full textSARS-CoV-2 represents the greatest epidemiological, clinical, and social challenge the human being has had to face in this century. SARS-CoV-2 is not merely a respiratory virus, as its target cells range from upper airway respiratory cells to pulmonary cells but also and above all to the cardiovascular cells, such as pericytes and endothelial cells. Indeed, the pathology related to SARS-CoV-2, COVID-19, may be defined as a thromboinflammatory syndrome in its most severe form, characterized by sepsis-induced coagulopathy (SIC) and disseminated intravascular coagulopathy (DIC), which is prevalent in individuals already presenting a chronic level of inflammation (e.g., obese individuals, elderly) and hypertension. Pregnancy is not only an inflammatory-prone condition but is characterized by a consistent rearrangement of the blood circulation and coagulation profile. Cardiac output increases while arterial systolic and diastolic pressure decrease, regardless of the activation of the RAS system. ACE2, the SARS-CoV-2 entry receptor into the host cells, which transforms Ang II in Ang 1–7, is highly expressed in endothelial, smooth muscle cells and pericytes of placental villi, regulating blood pressure and fetal development. Pre-eclampsia is a pregnancy disorder characterized by hypertension and low levels of ACE2, endothelial dysfunction, and a high production of pro-inflammatory cytokines, resembling COVID-19 manifestations. Whereas pre-eclampsia and COVID-19 have overlapping clinical features, a role for SARS-CoV-2 as a leading cause of pre-eclampsia in COVID-19 positive pregnant women has not been clarified yet. In this mini-review, we will explore the possibility of the existence of such a link, focusing on the role of endothelial dysfunction and RAS in both pre-eclampsia and SARS-CoV-2-induced COVID-19 pathogenesis
Correlation of nitrosyl (NO) stretching frequencies with coordination modes in metal complexes of C-nitroso compounds
No full textIt is shown that the previous use of IR spectroscopy for detn. of the co-ordination mode of p-nitrosodimethylaniline (I) is generally unreliable owing to a faulty assignment of the NO stretching frequency for I itself
Fetal growth restriction and maternal cardiac function
No full textCardiac output rises in pregnancy, and most of this increase occurs in the first trimester. Both heart rate and stroke volume contribute to this increase, which, coupled with a decrease in mean arterial pressure, determines a reduction of maternal total vascular resistance (TVR) in physiological pregnancy. The absence of a 'correct' maternal cardiovascular compensatory response (absence of increase in cardiac output, heart rate, stroke volume, left ventricular mass and decrease in maternal TVR), in addition to abnormal trophoblastic invasion, might be one of the factors that could determine a reduced placental perfusion and, eventually, the development of fetal intrauterine growth restriction (IUGR). In fact, pregnancies complicated by IUGR appear to lack the stimulus to induce the hemodynamic changes typically present in physiological pregnancy such as the increase in preload, maternal heart rate, stroke volume, the enlargement of the left atrium and, above all, the reduction of TVR. It is difficult to establish whether these hemodynamic alterations found in IUGR patients develop from the early stages of pregnancy, but if future studies are able to support this hypothesis, this will open the opportunity to identify patients in a preclinical state and eventually treat them with new pharmacological protocol
Nitrogen-oxygen bond length/stretching frequency relationships in C-nitroso compounds and their coordination complexes
No full textThe mode of coordination of monomeric C-nitroso compds. to metals is discussed. In contrast to previous studies it is proposed that an understanding of the ν(N-O)/r(N-O) and r(C-N)/r(N-O) relationships in the noncoordinated nitroso compds. is of primary importance for assessment of the coordination mode. Both ν(N-O)/r(N-O) and r(C-N)/r(N-O) have linear interrelationships in C-nitroso compds. and the coordination compds. of RNO have the same ν(N-O)/r(N-O) relationship as the noncoordinated monomers. Previous correlations of Δν(N-O) with coordination mode are therefore correlations of r(N-O) with coordination mode. σ-N and σ-O complexes of arom. RNO conform to the same r(C-N)/r(N-O) equation (within a very small error) as the noncoordinated monomers. The extent of deviation from the r(C-N)/r(N-O) relationship for complexes of aliph. RNO is of a similar order of magnitude to that which occurs when C-nitroso monomers form the trans dimer. The coordination mode of aliph. RNO is, with one exception, σ-N. Nitrosobenzene has a variety of coordination modes to transition metals but does not display σ-O coordination. p-Nitrosodimethylaniline undergoes σ-O coordination to d10 metals
Pre-eclampsia: One name, two conditions - The case for early and late disease being different
No full textThe identification of a patient simply as "preeclamptic" on the basis of elevated blood pressure and proteinuria is not sufficient to express the real haemodynamic adaptation of that mother. The importance of measuring cardiac output, stroke volume and total vascular resistance (TVR) is increasingly consistent with bedside observations from these patints. Clinicians should understand that to differentiate between the types of pre-eclampsia they should try to obtain as much information from the heart and cardiovascular system of the mother. The presence of elevated TVR characterizes more frequently the early "placental" PE. The presence of reduced TVR characterizes more frequently the late "metabolic" PE. These data, and not only the blood pressure alone, will help in the choice of the best treatment to be utilized in the effort of gaining days or weeks to induce foetal lung maturation and prepare the best possible maternal and neonatal conditions at birth. © 2013 Cambridge University Press
Restricted physical activity and maternal rest improve fetal growth: should we look for the reason in the cardiovascular modifications?
No full textIntrauterine growth restriction seems to be characterized
by a high-resistance, low cardiac output state that is detectable
at 22 to 24 weeks’ gestation in the preclinical stages of the
disease.2 This cardiovascular profile seems to be present at
different degrees of expression in the early and the late forms
of the disease. The low cardiac output may be because of 2
main reasons, namely the hypovolemic state and the possible
mechanical compression of the inferior vena cava.
During physical activity, the blood flow may be redirected
to the muscles. In case of normal plasma volume expansion
and maternal cardiovascular performance, physical activity
may have no effect on placental perfusion and fetal growth. If
plasma volume is not adequate and cardiac output is lower
than it should be, the redirection of part of the blood flow to
the muscles might steal precious blood from the placenta
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