Search Results - (Author, Cooperation:G. Grassi)

2018-08-24

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Geosciences

Computer Science

Medicine

Natural Sciences in General

Physics

Geochemistry, Geophysics, Planetary Science

2015-10-24

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

Rotational spectra of both conformers of glyoxal-d1 have been investigated in the 7.8–18 GHz region. The asymmetric isotopic labeling induces in the s-trans conformer a small permanent electric dipole moment. Exploiting the unique properties of a pulsed Fourier transform spectrometer 20 of the extremely weak rotational transitions of s-trans glyoxal-d1 have been observed and assigned. Three rotational constants and four quartic centrifugal distortion constants have been determined from the frequencies of transitions with J≤22. Nuclear quadrupole hyperfine splittings have been resolved for two low J transitions. Approximate values for the quadrupole coupling constants have been obtained therefrom. In addition, 16 transitions of s-cis glyoxal-d1 have been observed and assigned. From the transition frequencies with J≤22 improved rotational constants have been derived along with all quartic centrifugal distortion constants.

Electronic Resource

1365-3040

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Seedlings of Eucalyptus grandis were grown at five different rates of nitrogen supply. Once steady-state growth rates were established, a detailed set of CO2 and water vapour exchange measurements were made to investigate the effects of leaf nitrogen content (N), as determined by nitrogen supply rate, on leaf structural, photosynthetic, respiratory and stomatal properties. Gas exchange data were used to parametrize the Farquhar–von Caemmerer photosynthesis model. Leaf mass per area (LMA) was negatively correlated to N. A positive correlation was observed between both day (Rd) and night respiration (Rn) and N when they were expressed on a leaf mass basis, but no correlation was found on a leaf area basis. An Rd/Rn ratio of 0·59 indicated a significant inhibition of dark respiration by light. The maximum net CO2 assimilation rate at ambient CO2 concentration (Amax), the maximum rate of potential electron transport (Jmax) and the maximum rate of carboxylation (Vcmax) significantly increased with N, particularly when expressed on a mass basis. Although the maximum stomatal conductance to CO2 (gscmax) was positively correlated with Amax, there was no relationship between gscmax and N. Leaf N content influenced the allocation of nitrogen to photosynthetic processes, resulting in a decrease of the Jmax/Vcmax ratio with increasing N. It was concluded that leaf nitrogen concentration is a major determinant of photosynthetic capacity in Eucalyptus grandis seedlings and, to a lesser extent, of leaf respiration and nitrogen partitioning among photosynthetic processes, but not of stomatal conductance.

Electronic Resource

1365-3040

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Prunus avium trees were grown in sand culture for one vegetative season with contrasting N supplies, in order to precondition their N storage capacities. During the spring of the second year a constant amount of 15N was supplied to all the trees, and the recovery of unlabelled N in the new biomass production was used as a direct measure of N remobilization. Destructive harvests were taken during spring to determine the pattern of N remobilization and uptake. Measurements of both xylem sap amino acid profiles and whole tree transpiration rates were taken, to determine whether specific amino acids are translocated as a consequence of N remobilization and if remobilization can be quantified by calculating the flux of these amino acids in the xylem. Whereas remobilization started immediately after bud burst, N derived from uptake by root appeared in the leaves only 3 weeks later. The tree internal N status affected both the amount of N remobilization and its dynamics. The concentration of xylem sap amino acids peaked shortly after bud burst, concurrently with the period of fastest remobilization. Few amino acids and amides (Gln, Asn and Asp) were responsible for most of N translocated through the xylem; however, their relative concentration varied over spring, demonstrating that the transport of remobilized N occurred mainly with Gln whereas transport of N taken up from roots occurred mainly with Asn. Coupling measurements of amino acid N in the xylem sap with transpiration values was well correlated with the recovery of unlabelled N in the new biomass production. These results are discussed in relation to the possibility of measuring the spring remobilization of N in field-grown trees by calculating the flux of N translocation in the xylem.

Electronic Resource

0022-2860

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Physics

Electronic Resource

0022-2860

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Physics

Electronic Resource

0022-2852

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Physics

Electronic Resource

0584-8539

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Physics

Electronic Resource

0009-2614

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Physics

Electronic Resource

0040-4039

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

0040-4039

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

0040-4020

Benzonitrile Oxide ; E/Z hydrazoximes ; Methylhydrazones ; Oxatriazines ; Triazoles ; X-ray Diffraction.

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

0040-4039

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

0040-4039

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

1573-0794

Springer Online Journal Archives 1860-2000

Geosciences

Physics

Abstract Continuous radio-wave monitoring of the Geminid activity in December 1992 and 1993 by using a forward scatter (FS) bistatic radar over the Bologna-Lecce baseline (700 km) in Italy, reveals peculiar structural aspects of the stream in terms of signal amplitude-rate and duration-rate dependence. The observational results of the Geminid display obtained in the two consecutive years with differentiated peak levels of transmitted power, exhibit different time distributions of underdense meteors against the signal received power. Both sets of the data relative to the peak activity in December 12–14, show reflection properties of Geminids which are atypical if compared with echoes from cometary-type showers, with really high echo counts at mid-upper levels of the peak received power. An assymmetric curve of activity of the Geminids complex is evidenced, with the peak flux of smaller particles occurring earlier than that of larger ones.

Electronic Resource

0391-4240

History

SAGGI

1432-1041

Key words Amiodarone analogues ; 5′-T4 deiodinase ; Deiodination

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Abstract Objectives: Amiodarone (AMI) has proven to be a potent anti-arrhythmic compound. Due to the structural similarity between AMI and thyroid hormone, it is possible that the drug could inhibit the activity of the 5′-thyroxine-deiodinase. Methods: AMI analogues resulting from (1) dealkylation, (2) deiodination and (3) deamination were synthesised and used as inhibitors in an in vitro biotransformation reaction of thyroxine (T4) to 3,3′,5′-triiodothyronine (T3). Using high-performance liquid chromatography and ultraviolet detection for quantifying T3, it was found that the 5′-T4 deiodinase type I was involved in the reaction. On separate occasions, AMI or an AMI analogue was added to the reaction as an inhibitor. Results: All studied AMI analogues inhibited 5′-T4 deiodination competitively (K i value range 25–360 μM). In the concentration range of 1–1000 μM, AMI and its N-desethylated, deiodinated analogues inhibited 5′-T4 deiodination very weakly. AMI analogues with a hydroxyl group at the 4-position were strong inhibitors. Moreover, diiodo-AMI analogues inhibited 5′-T4 deiodination more strongly than their corresponding monoiodo- or deiodinated derivatives. Conclusion: It is likely that the degraded products of AMI could be responsible for thyroid dysfunction toxicosis in AMI therapy.

Electronic Resource

1432-1041

algorithm ; viloxazine ; depression ; side effects ; depressive symptoms ; Hamilton Rating Scale

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Summary Ninety-six depressed outpatients from 5 centres were given viloxazine 200–400 mg/day. The treatment produced significant clinical improvement as evaluated by the Hamilton Rating Scale for Depression. Thirteen patients dropped-out because of possible side effects. Many untoward symptoms were described by all the patients. To distinguish between illness-related symptoms (IRSs) and potential side effect symptoms (SESs) a new approach was taken, using an algorithm that provides a decision strategy based on the time course both of the symptom and the illness. By this procedure, 90 of the 187 claimed untoward symptoms were identified as IRSs. Of the 97 potential SESs, only 36 were spontaneously volunteered, and the remaining 61 symptoms were elicited on specific questioning. Whenever possible, volunteered potential SESs were assessed to determine the relationship between the drug treatment and the adverse reaction. It was found that only a few instances of gastric disturbance and exacerbation of anxiety were probably violxazine-related.

Electronic Resource

1432-5233

Albumin ; Diabetes ; Dialysis ; High risk ; Incidence

Springer Online Journal Archives 1860-2000

Medicine

Abstract Different incidence rates of new diabetic patients on dialysis are reported in various settings; although prevalence of this disease is often considered a marker of acceptance policy, rates are thought to be influenced also by genetic, epidemiological and other characteristics of a population (genetic composition, age distribution, lifestyle). Moreover, since features of a general population are often not stable (as in the setting analysed) changes at this level may have important reflections in the incidence of diabetics with end-stage renal disease (ESRD). In the region studied (Piedmont, northern Italy, about 4400 000 inhabitants, 20 dialysis centres, open acceptance since the mid-1970s, yearly information on 100% of patients, gathered by a Dialysis and Transplantation Registry) the incidence of diabetic patients with ESRD (389 cases recorded 1981–1990: 222 males, 167 females: mean age at start increasing from 55.5 years in 1981–1985 to 58.7 years in 1986–1990) differs according to age and sex. Incidence was higher in males, and rose from 6.23/year patients per million population (p.m.p.) in 1981–1982 to 12.88/year p.m.p. in 1989–1990, with a peak at age 60–69 (from 18.46/year p.m.p. in 1981–1982, to 46.12/year p.m.p. in 1989–1990). While relatively stable in the younger age groups from 1981 to 1990, incidence increased in the elderly (males age 70–79: 7.12/year p.m.p. in 1981–1982, 26.08/year p.m.p. in 1989–1990). As regards clinical and metabolic patterns, at the first update, in 1986–1990, 88.3% of diabetic patients were hypertensive or taking hypotensive drugs; albumin levels were below the normal range (〈3.5 g/dl) in 30.3%; cholesterol levels were below the normal range (〈150 mg/dl) in 16.15%. As regards entry criteria, creatinine clearances ranged from 〈1 to 14 ml/min (mean values at first update: 3.45±2.76 ml/min). In conclusion, presentation of diabetic patients with ESRD is changing. The stability of incidence in the younger age groups confirms the appropriateness of an open acceptance policy, at least for these ages. The increase in the elderly probably reflects the longer lifespan of diabetic patients in the overall population, while the influence of a hidden preselection must be further assessed. Since this cohort increasingly requires in-hospital high-tolerance treatment, future provision of dialysis needs must take into account the trend towards an increase in this high-risk elderly population.

Electronic Resource