Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 16 de 16
Filter
1.
Neurosci Lett ; 811: 137333, 2023 08 10.
Article in English | MEDLINE | ID: mdl-37311507

ABSTRACT

OBJECTIVE: Prospective memory (PM) refers to the ability to perform expected actions in the future. The purpose of this study is to investigate the role of stimuli with emotional content on the prospective memory, with particular attention to different age groups. METHODS: Starting from an experimental paradigm used in a previous study (by Cona et al., 2015), we evaluated whether emotional cues (positive, negative, or neutral images) did influence a prospective memory task based on the event during the performance of an ongoing n-back task in three different age groups. RESULTS: A difference emerged between the three investigated groups indicating that positive emotional cues were remembered better than negative and neutral ones. In addition, older subjects resulted slower than others in responding to stimuli and showed the tendency to make more errors in the prospective memory task. CONCLUSIONS: As hypothesized, a difference in the performance of the task appears as due to age. In general, the younger participants take the test more accurately (i.e., with fewer errors). This could be explained because the prospective memory deteriorates with increasing age. Behavioral results do not yet allow us to answer the research question on the role of emotional material in prospective memory; more research is needed to clarify these issues.


Subject(s)
Cues , Memory, Episodic , Humans , Emotions , Mental Recall
2.
Water Res ; 149: 522-532, 2019 02 01.
Article in English | MEDLINE | ID: mdl-30500687

ABSTRACT

Quantification of the (spatially distributed) natural contributions to the chemical signature of groundwater resources is an emerging issue in the context of competitive groundwater uses as well as water regulation and management frameworks. Here, we illustrate a geostatistically-based approach for the characterization of spatially variable Natural Background Levels (NBLs) of target chemical species in large-scale groundwater bodies yielding evaluations of local probabilities of exceedance of a given threshold concentration. The approach is exemplified by considering three selected groundwater bodies and focusing on the evaluation of NBLs of ammonium and arsenic, as detected from extensive time series of concentrations collected at monitoring boreholes. Our study is motivated by the observation that reliance on a unique NBL value as representative of the natural geochemical signature of a reservoir can mask the occurrence of localized areas linked to diverse strengths of geogenic contributions to the groundwater status. We start from the application of the typical Pre-Selection (PS) methodology to the scale of each observation borehole to identify local estimates of NBL values. The latter are subsequently subject to geostatistical analysis to obtain estimates of their spatial distribution and the associated uncertainty. A multimodel framework is employed to interpret available data. The impact of alternative variogram models on the resulting spatial distributions of NBLs is assessed through probabilistic weights based on model identification criteria. Our findings highlight that assessing possible impacts of anthropogenic activities on groundwater environments with the aim of designing targeted solutions to restore a good groundwater quality status should consider a probabilistic description of the spatial distribution of NBLs. The latter is useful to provide enhanced information upon which one can then build decision-making protocols embedding the quantification of the associated uncertainty.


Subject(s)
Arsenic , Groundwater , Water Pollutants, Chemical , Environmental Monitoring
3.
Nanoscale ; 8(28): 13678-86, 2016 Jul 14.
Article in English | MEDLINE | ID: mdl-27376633

ABSTRACT

Tuning the intermolecular interactions among suitably designed molecules forming highly ordered self-assembled monolayers is a viable approach to control their organization at the supramolecular level. Such a tuning is particularly important when applied to sophisticated molecules combining functional units which possess specific electronic properties, such as electron/energy transfer, in order to develop multifunctional systems. Here we have synthesized two tetraferrocene-porphyrin derivatives that by design can selectively self-assemble at the graphite/liquid interface into either face-on or edge-on monolayer-thick architectures. The former supramolecular arrangement consists of two-dimensional planar networks based on hydrogen bonding among adjacent molecules whereas the latter relies on columnar assembly generated through intermolecular van der Waals interactions. Scanning Tunneling Microscopy (STM) at the solid-liquid interface has been corroborated by cyclic voltammetry measurements and assessed by theoretical calculations to gain multiscale insight into the arrangement of the molecule with respect to the basal plane of the surface. The STM analysis allowed the visualization of these assemblies with a sub-nanometer resolution, and cyclic voltammetry measurements provided direct evidence of the interactions of porphyrin and ferrocene with the graphite surface and offered also insight into the dynamics within the face-on and edge-on assemblies. The experimental findings were supported by theoretical calculations to shed light on the electronic and other physical properties of both assemblies. The capability to engineer the functional nanopatterns through self-assembly of porphyrins containing ferrocene units is a key step toward the bottom-up construction of multifunctional molecular nanostructures and nanodevices.

4.
Environ Sci Pollut Res Int ; 21(3): 1628-1637, 2014 Feb.
Article in English | MEDLINE | ID: mdl-23949112

ABSTRACT

Dissolved arsenic (As) concentrations detected in groundwater bodies of the Emilia-Romagna Region (Italy) exhibit values which are above the regulation limit and could be related to the natural composition of the host porous matrix. To support this hypothesis, we present the results of a geochemical modeling study reproducing the main trends of the dynamics of As, Fe, and Mn concentrations as well as redox potential and pH observed during batch tests performed under alternating redox conditions. The tests were performed on a natural matrix extracted from a deep aquifer located in the Emilia-Romagna Region (Italy). The solid phases implemented in the model were selected from the results of selective sequential extractions performed on the tested matrix. The calibrated model showed that large As concentrations have to be expected in the solution for low crystallinity phases subject to dissolution. The role of Mn oxides on As concentration dynamics appears significant in strongly reducing environments, particularly for large water-solid matrix interaction times. Modeled data evidenced that As is released firstly from the outer surface of Fe oxihydroxides minerals exhibiting large concentrations in water when persistent reducing conditions trigger the dissolution of the crystalline structure of the binding minerals. The presence of organic matter was found to strongly affect pH and redox conditions, thus influencing As mobility.


Subject(s)
Arsenic/analysis , Groundwater/chemistry , Models, Chemical , Water Pollutants, Chemical/analysis , Italy , Minerals/chemistry , Oxidation-Reduction
5.
Sci Total Environ ; 444: 231-40, 2013 Feb 01.
Article in English | MEDLINE | ID: mdl-23274242

ABSTRACT

We investigated the role of iron (Fe) on arsenic (As) release from two samples of a natural deep soil collected in an aquifer body in the Emilia-Romagna Region, Italy. Each sample is representative of a different solid matrix, i.e., sand and vegetal matter. Batch experiments were performed by applying alternating aerobic/anaerobic conditions to the samples under a range of redox and pH conditions, consistent with the corresponding values measured in the field. Arsenic mobilization was triggered by abrupt and rapid changes in redox conditions and displayed a clear correlation with oxidation/reduction potential for both solid matrices. Vegetal matter showed high binding capacity and large As concentration release. Arsenic release was also correlated with Fe released from the solid matrices. Our results suggest that the environmentally critical As concentrations detected in some aquifers in the Emilia-Romagna Region are consistent with (a) the occurrence of high natural As content in the component of the host porous medium associated with vegetal matter and (b) the effect of possible sharp localized (and temporally oscillating) variations in redox conditions.


Subject(s)
Arsenic/chemistry , Soil Pollutants/chemistry , Water Pollutants, Chemical/chemistry , Chemistry, Physical/instrumentation , Chemistry, Physical/methods , Equipment Design , Groundwater/chemistry , Hydrogen-Ion Concentration , Iron/chemistry , Italy , Oxidation-Reduction
7.
Chemistry ; 7(8): 1597-605, 2001 Apr 17.
Article in English | MEDLINE | ID: mdl-11349899

ABSTRACT

A fullerene derivative (5) in which a dinuclear ruthenium complex is covalently linked to a fulleropyrrolidine (FP) through a rigid spacer has been prepared through azomethine ylide cycloaddition to C60. Electrochemical and photophysical studies revealed that ground-state electronic interactions between the bimetallic ruthenium chromophore and the FP moiety are small. The absorption spectrum of 5 displays a metal-to-ligand charge transfer (MLCT) transition at about 620 nm in CH2Cl2 which is shifted by nearly 160 nm relative to that of a previously reported mononuclear dyad (8). The photophysical investigations have also shown that both in dichloromethane and acetonitrile the photoexcited MLCT state of dyad 5 transforms into the fullerene triplet excited state with a quantum yield of 0.19 and that, contrary to mononuclear dyad 8, electron transfer, if any under the applied conditions, is negligible relative to energy transfer.


Subject(s)
Energy Transfer , Fullerenes , Metalloporphyrins/chemistry , Photosensitizing Agents/chemistry , Ruthenium/chemistry , Carbon , Electrochemistry , Molecular Structure , Oxygen/chemistry , Photolysis , Singlet Oxygen , Spectrophotometry, Atomic , Spectrophotometry, Ultraviolet
8.
Surgery ; 128(4): 660-7, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11015100

ABSTRACT

BACKGROUND: In this study of laparoscopic splenectomy (LS), we evaluate prospectively gathered perioperative patient data and review lessons learned in the evolution of this procedure. METHODS: At 2 university medical centers between November 1993 and March 2000, there were 203 patients (122 female patients and 81 male patients) who underwent LS after preoperative evaluation. RESULTS: LS was successfully completed in 197 patients (97%). The mean operative time was 145.5 minutes and the length of stay averaged 2.7 days with 143 (70.4%) staying less than 48 hours. The most common indication was idiopathic thrombocytopenic purpura (ITP). Six patients required conversion to open splenectomy (OS), with only 2 conversions in the last 163 cases. No deaths were attributed to the procedure. Complications occurred in 19 patients (9.3%). Thirty accessory spleens were identified in 25 patients (12.3%). Seventeen patients (8.4%) underwent concomitant procedures, most commonly cholecystectomy. CONCLUSIONS: LS by the lateral approach is both safe and feasible in patients of all ages.


Subject(s)
Laparoscopy , Purpura, Thrombocytopenic, Idiopathic/surgery , Splenectomy/methods , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Postoperative Complications , Prospective Studies , Splenic Diseases/surgery , Treatment Outcome
9.
Semin Hematol ; 37(3): 267-74, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10942221

ABSTRACT

Splenectomy remains the definitive treatment for idiopathic thrombocytopenic purpura (ITP). Issues related to timing of splenectomy, perioperative management of platelet count, deep vein thrombosis prophylaxis, and preoperative vaccination are not standardized. Predicting the outcome of splenectomy is desirable but, again, consistent evidence for a particular approach is lacking. Laparoscopic splenectomy, first introduced in 1991, has removed some of the barriers to acceptance of splenectomy and may well change its place in the various treatment algorithms. This article reviews current knowledge with respect to laparoscopic splenectomy and provides an analysis of current evidence regarding issues of safety, efficacy, and cost effectiveness. Surgical technique is briefly reviewed. The information is drawn from a comprehensive analysis of the literature, as well as my own large experience with laparoscopic splenectomy, the majority of which has been focused on laparoscopic splenectomy for ITP.


Subject(s)
Laparoscopy , Purpura, Thrombocytopenic, Idiopathic/surgery , Splenectomy/methods , Chronic Disease , Costs and Cost Analysis , Humans , Splenectomy/economics , Splenectomy/standards , Treatment Failure
10.
J Environ Monit ; 2(5): 529-33, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11254061

ABSTRACT

The QUASH UE-Project was designed to assess the reliability of normalisation approaches to compensate the influence of natural process affecting the distribution and concentration of contaminants in sediment. The focus of this paper was to test the influence on normalisation procedures of an inorganic matrix using a sample collected in the Venice Lagoon, Italy.


Subject(s)
Environmental Monitoring , Environmental Pollutants/analysis , Geologic Sediments/chemistry , Organic Chemicals/analysis , Reference Values , Reproducibility of Results
11.
Arch Surg ; 134(11): 1263-9, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10555644

ABSTRACT

HYPOTHESIS: Laparoscopic splenectomy (LS) provides health benefits to patients compared with open splenectomy (OS) in terms of perioperative morbidity, complications, and patient recuperation. DESIGN: Prospective operative and outcome data of LS patients were compared with those of OS patients (historical controls). SETTING: Data were gathered, and patients were evaluated and treated at 2 McMaster University teaching hospitals in Hamilton, Ontario, and at the University of Kentucky Chandler Medical Center, Lexington, also a teaching hospital. PATIENTS: From January 1, 1994, through October 31, 1998, a total of 210 patients were studied. Of them, 147 patients from 3 university teaching hospitals underwent LS. These patients were matched with 63 OS patients according to age, sex, spleen weight, indication for splenectomy, and preoperative morbidity score. INTERVENTIONS: A total of 147 patients evaluated for elective splenectomy underwent LS. MAIN OUTCOME MEASURES: Spleen weight, operative time, intraoperative blood loss, postoperative hospital stay, perioperative complications, and cost. RESULTS: No significant difference in mean spleen weight was found between groups. Mean operative time was significantly longer for LS, but intraoperative blood loss was significantly lower. Mean postoperative hospital stay was significantly lower and perioperative complications significantly fewer for LS patients. Mean cost for LS with no complications was slightly lower than for OS. CONCLUSIONS: Compared with OS, the lateral approach to LS takes longer to perform but results in reduced blood loss, shorter postoperative stay, and fewer complications. Mean weighted cost of LS is lower than OS at the study institutions. A prospective, randomized, controlled trial comparing these techniques is planned.


Subject(s)
Laparoscopy , Splenectomy/methods , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Humans , Laparoscopy/adverse effects , Male , Middle Aged , Postoperative Complications/epidemiology , Prospective Studies , Splenectomy/adverse effects
12.
13.
N Engl J Med ; 336(21): 1494-8, 1997 May 22.
Article in English | MEDLINE | ID: mdl-9154768

ABSTRACT

BACKGROUND: High-dose intravenous immune globulin produces a temporary rise in the platelet count in patients with idiopathic thrombocytopenic purpura. Splenectomy may also be effective, but it is not possible to predict which patients will have a good response. We hypothesized that the response to intravenous immune globulin predicts the response to splenectomy. METHODS: We studied retrospectively 30 patients with idiopathic thrombocytopenic purpura who had first been treated with immune globulin and then undergone splenectomy. The responses to the two treatments were classified on the basis of the platelet count as poor (<50,000 per cubic millimeter), good (50,000 to 150,000 per cubic millimeter), or excellent (>150,000 per cubic millimeter). RESULTS: All nine patients who had poor responses to intravenous immune globulin also had poor responses to splenectomy at one year. Of the 21 patients with good or excellent responses to intravenous immune globulin, 19 had good or excellent responses to splenectomy. CONCLUSIONS: Patients with idiopathic thrombocytopenic purpura who have good or excellent responses to intravenous immune globulin are likely to have good or excellent responses to splenectomy, whereas patients who have poor responses to intravenous immune globulin are unlikely to have good or excellent responses to splenectomy.


Subject(s)
Immunoglobulins, Intravenous/administration & dosage , Purpura, Thrombocytopenic, Idiopathic/therapy , Splenectomy , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Platelet Count , Predictive Value of Tests , Purpura, Thrombocytopenic, Idiopathic/surgery , Retrospective Studies , Sensitivity and Specificity , Treatment Outcome
14.
Surg Endosc ; 10(8): 859-61, 1996 Aug.
Article in English | MEDLINE | ID: mdl-8694957

ABSTRACT

Laparoscopic splenectomy in children has been shown to be safe, to reduce postoperative pain and hospital stay, and to accelerate return to full activities. We describe our experience with a four-port "lateral" approach in 18 patients. Patients were placed in the lateral decubitus position and the table was flexed to separate the left subcostal margin and iliac crest. The camera port was inserted at the umbilicus and additional ports were placed in the epigastrium and left lower quadrant. After mobilization of the splenic flexure a port was inserted in the left flank below the 12th rib for elevation of the spleen. A 30 degrees laparoscope was used and the splenic vessels were controlled with an endo-GIA and/or clips. The spleens were placed in a bag, morcellated, and extracted through a port site. Eight females and 10 males with a median age of 12.5 years (5-17 years) and weight of 55.5 kg (17-124 kg) underwent splenectomy of idiopathic thrombocytopenia purpora (10), spherocytosis (6), elliptocytosis (1), and Hodgkin's disease (1). The median operating time was 160 min (90-300 min) and median blood loss was 105 ml (5-350 ml). Accessory spleens were removed in four cases. Three patients required extensions of a port site to remove large spleens which could not be placed in a bag. The sole complication was a transient pancreatitis with associated pleural effusion. The median postoperative hospital stay was 2 days (1-11 days) and time to full activities was 8 days (3-25 days). The lateral approach affords excellent visualization of the splenic vessels, pancreas, and accessory spleens. This approach is safe and reliable and is our preferred approach for laparoscopic splenectomy in children.


Subject(s)
Laparoscopy/methods , Splenectomy/methods , Splenomegaly/surgery , Adolescent , Child , Child, Preschool , Female , Humans , Length of Stay , Male , Retrospective Studies , Treatment Outcome
15.
Can J Surg ; 36(2): 162-4, 1993 Apr.
Article in English | MEDLINE | ID: mdl-8329032

ABSTRACT

Anastomotic ulcers are a rare late complication of ileocolic resection in children. The authors describe the cases of two patients who presented 10 and 8 years, respectively, after ileocolic resection. Both had suffered from iron-deficiency anemia caused by an anastomotic ulcer. In one patient the anemia improved after resection of the ulcer; in the second patient cholestyramine and a lactose-free diet resolved the problems of anemia and diarrhea. Anastomotic ulceration should be suspected in any child who has undergone an ileocolic anastomosis and subsequently presents with persistent iron-deficiency anemia and occult blood in the stool.


Subject(s)
Anastomosis, Surgical/adverse effects , Anemia, Hypochromic/etiology , Colon/surgery , Ileum/surgery , Intestinal Diseases/etiology , Occult Blood , Child, Preschool , Female , Humans , Infant, Newborn , Intestinal Diseases/diagnosis , Intestinal Diseases/surgery , Male , Reoperation , Time Factors , Ulcer
16.
Can J Surg ; 29(6): 405-7, 1986 Nov.
Article in English | MEDLINE | ID: mdl-3779542

ABSTRACT

The authors reviewed retrospectively 368 breast lumps subjected to fine-needle aspiration cytology alone or to open biopsy as well. Of those lumps for which the results of both studies were available, there were 39 true-positive results, 32 true-negative, 1 false-positive and 7 false-negative results when the definitive findings of fine-needle aspiration biopsy were compared with the histologic features. Also, in the 40 patients in whom the aspirate was suggestive of malignancy or the findings were atypical, 22 had malignant disease on open biopsy and 18 had benign disease. These results are consistent with those reported in the literature and point to the importance of a positive or suggestive report and the current unreliability of a negative report.


Subject(s)
Biopsy, Needle , Breast Neoplasms/pathology , Breast/pathology , Aged , Breast Neoplasms/diagnosis , False Negative Reactions , False Positive Reactions , Female , Humans , Middle Aged , Retrospective Studies
SELECTION OF CITATIONS
SEARCH DETAIL
...