ABSTRACT—Age-related endothelial dysfunction could be caused by an alteration in the l-arginine-NO system and the production of oxidative stress in both normotensive and hypertensive individuals. In ...47 normotensive subjects and 49 patients with essential hypertension, we evaluated forearm blood flow (by strain-gauge plethysmography) modifications induced by intrabrachial sodium nitroprusside (1, 2, and 4 μg/100 mL per minute) and acetylcholine (0.15, 0.45, 1.5, 4.5, and 15 μg/100 mL per minute), an endothelium-independent vasodilator and an endothelium-dependent vasodilator, respectively. Acetylcholine was repeated in the presence of the NO synthase inhibitor N-monomethyl-l-arginine (L-NMMA, 100 μg/100 mL per minute), the antioxidant vitamin C (8 mg/100 mL per minute), or both. Vasodilation to acetylcholine, but not to sodium nitroprusside, was lower (P <0.01) in hypertensive patients compared with control subjects. Moreover, in both groups, endothelium-dependent vasodilation declined with aging. In normotensive subjects, the inhibiting effect of L-NMMA on response to acetylcholine decreased in parallel with advancing age, whereas vitamin C increased vasodilation to acetylcholine in only the oldest group (age >60 years). In young hypertensive patients (age <30 years), vasodilation to acetylcholine was sensitive to L-NMMA, whereas in hypertensive patients age >30 years, vitamin C enhanced endothelium-dependent vasodilation and restored the inhibiting effect of L-NMMA on response to acetylcholine. In normotensive individuals, an earlier primary dysfunction of the NO system and a later production of oxidative stress cause age-related reduction in endothelium-dependent vasodilation. These alterations are similar but anticipated in hypertensive patients compared with normotensive subjects.
Abstract Aim of the present study was to evaluate the influence on the global model's accuracy of the strategy adopted to define the average element Young's modulus in subject-specific finite element ...models of bones from computed tomography data. The classic strategy of calculating the Young's modulus from an average element density and the one that averages the Young's moduli directly derived from each voxel Hounsfield Unit were considered. These strategies were applied to the finite element model of a real human femur. The accuracy of the superficial stress and strain predictions was evaluated against experimentally measured values in 13 strain-gauge locations for five different loading conditions. The results obtained for the two material distributions were statistically different. Both models predicted very accurately the superficial stresses, with regression coefficients higher than 0.9 and slopes not significantly different from unity. The second strategy definitely improved the strains prediction accuracy: the regression coefficient raised from 0.69 to 0.79; the average and peak errors decreased from 45.1% to 31.3% and from 228% to 134% of the maximum measured strain, respectively. The stress fields predicted inside the bone were also significantly different. A new software implementing the second strategy was made available in the public domain.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Successful liver transplantation offers the possibility of improved survival among patients with decompensated cirrhosis. However, there is wide variability in access to care and promptness of the ...transplant evaluation process in the United States.
We performed a multicenter retrospective study of 1118 patients who underwent evaluation for liver transplantation at the 6 Veterans Affairs' transplant centers from 2013 to 2018. Of these, 832 patients were evaluated within 30 d and 286 > 30 d after referral. We studied the differential effects of the time from referral to evaluation on pretransplant and posttransplant mortality and transplant list dropout and explored predictors of early transplant evaluation.
Patients in the early evaluation group had a shorter adjusted time from referral to listing by 29.5 d (95% confidence interval CI -50.4, -8.5, P < 0.006), and referral to transplantation by 115.1 d (95% CI -179.5, -50.7, P < 0.0001). On a multivariable Cox hazard model, evaluation within 30 d of referral was associated with a significantly lower pretransplant mortality (adjusted hazard ratio aHR 0.70, 95% CI 0.54-0.91, P < 0.01), but not associated with transplant list dropout (aHR 0.95, 95% CI 0.65-1.39, P = 0.79) or posttransplant death (aHR 1.88, 95% CI 0.72-4.9, P = 0.20). An early evaluation within 30 d was positively associated with a higher MELD at referral (aHR 1.03, 95% CI 1.01-1.06, P = 0.006) and negatively associated with distance from the transplant center (aHR 0.99, 95% CI 0.99-0.99, P = 0.045).
Evaluation of patients referred for liver transplantation within 30 d is associated with a reduction in pretransplant mortality.
The bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae is a severe threat to kiwifruit production worldwide. Many aspects of P. syringae pv. actinidiae biology and ...epidemiology still require in-depth investigation. The infection by and spread of P. syringae pv. actinidiae in xylem and phloem was investigated by carrying out artificial inoculation experiments with histological and dendrochronological analyses of naturally diseased plants in Italy. We found that the bacterium can infect host plants by entering natural openings and lesions. In naturally infected kiwifruit plants, P. syringae pv. actinidiae is present in the lenticels as well as in the dead phloem tissue beneath the lenticels, surrounded by a lesion in the periderm which appears to indicate the importance of lenticels to kiwifruit infection. Biofilm formation was observed outside and inside plants. In cases of advanced stages of P. syringae pv. actinidiae infection, neuroses of the phloem occur, which are followed by cambial dieback and most likely by infection of the xylem. Anatomical changes in wood such as reduced ring width, a drastic reduction in vessel size, and the presence of tyloses were observed within several infected sites. In the field, these changes occur only a year after the first leaf symptoms are observed suggesting a significant time lapse between primary and secondary symptoms. It was possible to study the temporal development of P. syringae pv. actinidiae-induced cambial dieback by applying dendrochronology methods which revealed that cambial dieback occurs only during the growing season.
Incineration has become an attractive option for municipal solid waste (MSW) management, due to its several benefits. In fact, it allows volume and mass reduction of waste and energy recovery from ...MSW combustion. Nevertheless, MSW incineration (MSWI) produces three main types of residues: bottom ash (BA), fly ash (FA) and air pollution control (APC) residues, which require an adequate handling. BA is the most significant by-product from MSWI and is generally considered as non-hazardous waste. Instead, FAs are included as hazardous wastes because are characterised by high content of chlorides, heavy metals and organic compounds. The aim of this paper was to examine the characteristics of MSWI solid residues, the management and reuse of these wastes and their environmental assessment from a life cycle perspective. It was noted that the main components that make up the residues are lead and zinc as well as oxides, mainly CaO, SiO
2
and Al
2
O
3
. Furthermore, it is necessary to take into account the presence of PCDD/F which characterised FA and APC residues, mainly due to chlorine content. Chemical and physical properties of those residues make possible their reuse as construction material, as adsorbent, as well as in geotechnical and agricultural applications. Nevertheless, several studies have demonstrated that a drawback of the reuse of MSWI residues is the existence of heavy metals in elevated concentrations which may affect the environmental quality. In this regard, many studies were aimed to assess the environmental impact related to the introduction of MSWI residues as secondary material in several fields of application.
Ethyl diazoacetate (EDA), which is easily prepared from ethyl glycinate and NaNO2, reacts in situ with alkynes in a water micelle environment without organic solvent to form pyrazoles. The reaction ...is pH dependent, as in the presence of protic catalysis (H2SO4 4 %, pH 3.5) a mixture of 3,5‐ and 4,5‐disubstituted pyrazoles was obtained, while, at pH 5.5, only the 3,5‐disubstituted isomer was obtained. The presence of the surfactant TPGS‐750‐M was crucial to secure clean crude reaction mixtures and high yields of the products. The same protocol was successfully applied to the synthesis of substituted pyrazolines.
In TPGS‐750‐M/water, ethyl diazoacetate can be generated in situ and used for a telescopic process to produce pyrazoles. Regioselectivity is controlled either in the micellar environment or in water by pH alone. The metal‐free reaction takes place in water with 1.5 % surfactant as the only additive and the purification of the pyrazoles can be done by crystallisation if possible.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Investigation into neuropsychiatric symptoms in Parkinson’s disease (PD) is sparse and current drug development is mainly focused on the motor aspect of PD. The tight association of psychosis with an ...impaired quality of life in PD, together with an important underreporting of this comorbid condition, contributes to its actual insufficient assessment and management. Furthermore, the withdrawal from access to readily available treatment interventions is unacceptable and has an impact on PD prognosis. Despite its impact, to date no standardized guidelines to the adequate management of PD psychosis are available and they are therefore highly needed. Readily available knowledge on distinct clinical features as well as early biomarkers of psychosis in PD justifies the potential for its timely diagnosis and for early intervention strategies. Also, its specific characterisation opens up the possibility of further understanding the underlying pathophysiological mechanisms giving rise to more targeted therapeutic developments in the nearer future. A literature review on the most recent knowledge with special focus on specific clinical subtypes and pathophysiological mechanisms will not only contribute to an up to date practical approach of this condition for the health care providers, but furthermore open up new ideas for research in the near future.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Open-skill sports require high levels of visual attention and fast and flexible decision making and action execution. We evaluated whether these sports may counteract the well-known age-related ...declines in executive processing.
Young and middle-age fencers and nonathletes were studied. Participants (N = 40) performed visual motor tasks while reaction times (RTs) and event-related potentials were recorded.
RTs were slower for the older subjects, but accuracy was not impaired. At event-related potential level, the late P3 component was delayed in older subjects, but those who participated in sports showed less delay. The RTs of middle-age and young fencers were comparable; the P1 latency of middle-age fencers was similar to that of the younger subjects; the N1 was enhanced in older, as well as younger, fencers; the N2 component of fencers had shorter latencies and larger amplitudes than nonathletes; and in no-go trials, the P3 component was enhanced in fencers independent of age.
Overall, the practice of open-skill sports was associated with improvement of the executive functions that are already degraded at middle age.
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