1,875 research outputs found
Dissociation Energies of the Ga2, In2, and GaIn Molecules
The group III metal dimers Ga2 and In2 and the newly identified intermetallic molecule GaIn were investigated in a Knudsen cell-mass spectrometric study of the vapors over gallium–indium alloys. From the all-gas equilibria analyzed by the second-law and third-law methods the following dissociation energies were derived; D00 (Ga2)=110.8±4.9 kJ mol−1, D00 (In2)=74.4±5.7 kJ mol−1, D00 (GaIn)=90.7±3.7 kJ mol−1. The value here measured for the dissociation energy of In2 is discussed and compared with a previous experimental determination and with the results of more recent theoretical investigations
Scaling theory of DNA confined in nanochannels and nanoslits
A scaling analysis is presented of the statistics of long DNA confined in
nanochannels and nanoslits. It is argued that there are several regimes in
between the de Gennes and Odijk limits introduced long ago. The DNA chain folds
back on itself giving rise to a global persistence length which may be very
large owing to entropic deflection. Moreover, there is an orientational
excluded-volume effect between the DNA segments imposed solely by the
nanoconfinement. These two effects cause the chain statistics to be intricate
leading to nontrivial power laws for the chain extension in the intermediate
regimes. It is stressed that DNA confinement within nanochannels differs from
that in nanoslits because the respective orientational excluded-volume effects
are not the same.Comment: 5 pages, 1 figure Several corrections, some minor changes in the text
and replacement of one referenc
Rapid review on covid-19, work-related aspects, and age differences
The COVID-19 pandemic significantly impacted the labor market and multiple aspects of work and workers’ life. The present rapid review analyzes this impact considering the effects that COVID-19 pandemic had on employment and work-related aspects across different age groups. A comprehensive literature search was performed on scientific contributions published between 2019 and March 2021, resulting in 36 papers pertinent to the scope of this review. Findings were grouped according to different topics, all linked to age: occupational risk, implications on the labor market (i.e., job loss and reemployment, job insecurity, turnover intentions and retirement, and healthcare workers’ return-to-work phase), remote work, and key individual and organizational resources and strategies. Overall, the review revealed variability across age groups in the impact this pandemic had on employment and several work-related aspects (i.e., occupational risk, remote work). Findings supported an age-differential effect of normative history-graded events such as the current pandemic, highlighting different responses and consequences depending on workers’ age
Experimental and Computational Study of the New Gaseous Molecules OMnF and OMnF[Sub 2]
The new gaseous species OMnF and OMnF2 were identified and studied by high-temperature Knudsen Cell Mass Spectrometry. Their thermochemical atomization energies were derived through the study of several all-gas equilibria in the temperature range 1735–1913 K. FTIR matrix isolation experiments together with ab initio and density functional calculations were performed to determine the molecular parameters, bond distances, and vibrational frequencies of OMnF(g) and OMnF2(g) . The results allowed us to evaluate a set of thermal functions for the new species that were used in the evaluation of the equilibrium data. The proposed atomization energies and enthalpies of formation are DaH0 + (OMnF,g)5(90365) kJ mol21, DfH298.15 + (OMnF,g)5(229765) kJ mol21, and DaH0 + (OMnF2 ,g)5(1470670) kJ mol21, DfH298.15 + (OMnF2 ,g)5(2789670) kJ mol21
Workaholism, intensive smartphone use, and the sleep-wake cycle: A multiple mediation analysis
Recent contributions have reported sleep disorders as one of the health impairment outcomes of workaholism. A possible factor affecting the sleep-wake cycle might be the intensive use of smartphones. The current study aimed to explore the role of intensive smartphone use in the relationship between workaholism and the sleep-wake cycle. Two serial multiple mediation models were tested on a sample of 418 employees, who filled self-report questionnaires measuring workaholism, use of smartphones, sleep quality and daytime sleepiness, using conditional process analysis for testing direct and indirect effects. Results supported our hypotheses regarding two serial multiple mediation models-that intensive smartphone use and poor sleep quality mediated the relationship between workaholism and daytime sleepiness, and that smartphone use and daytime sleepiness mediated the relationship between workaholism and poor quality of sleep. Although the use of a cross-sectional design and the snowball technique for collecting data can be considered as possible limitations, the current study is one of the first to document the potential detrimental role of the intensive smartphone use on the workaholism-sleep disorders relationship
Biochemical effects of urapidil on red cell membrane ion transport systems in a population of elderly essential hypertensives.
The aim of our work was to verify the effect of urapidil on membrane ion transport systems. This was a randomized, double-blind, cross-over study which evaluated the clinical and biochemical effects of urapidil (30 mg twice daily in comparison with placebo) in a group of 10 elderly hypertensive patients (3 male, 7 female ranging from 68 to 90 years, mean age 79.2 +/- 7.6 years). For the evaluation in fresh erythrocytes of principal ion transport systems (cotransport Na+/K+, countertransport Na+/Li+, Na+/K+ ATPase pump. intracellular Na+ and K+) we used the nystatin technique. We found that urapidil activated the red cell membrane ions cotransport system (basal values: 83.7 +/- 50.3 mumol Na+ RBC 1-1.h-1, after 1 month of urapidil therapy: 181.5 +/- 89.3 mumol Na+ RBC 1-1.h-1) (P less than 0.01), without significant changes in the other biochemical parameters evaluated. Our data suggest that one of the mechanisms of the urapidil antihypertensive effect could involve an increase in the membrane sodium cotransport system
Robotic versus open oncological gastric surgery in the elderly. a propensity score-matched analysis
Although there is no agreement on a definition of elderly, commonly an age cutoff of ≥ 65 or 75 years is used. Even if robot-assisted surgery is a validated option for the elderly population, there are no specific indications for its application in the surgical treatment of gastric cancer. The aim of this study is to evaluate the safety and feasibility of robot-assisted gastrectomy and to compare the short and long-term outcomes of robot-assisted (RG) versus open gastrectomy (OG). Patients aged ≥ 70 years old undergoing surgery for gastric cancer at the Department of Surgery of San Donato Hospital in Arezzo, between September 2012 and March 2017 were enrolled. A 1:1 propensity score matching was performed according to the following variables: age, Sex, BMI, ASA score, comorbidity, T stage and type of resection performed. 43 OG were matched to 43 RG. The mean operative time was significantly longer in the RG group (273.8 vs. 193.5 min, p < 0.01). No differences were observed in terms of intraoperative blood loss, an average number of lymph nodes removed, mean hospital stay, morbidity and mortality. OG had higher rate of major complications (6.9 vs. 16.3%, OR 2.592, 95% CI 0.623–10.785, p = 0.313) and a significantly higher postoperative pain (0.95 vs. 1.24, p = 0.042). Overall survival (p = 0.263) and disease-free survival (p = 0.474) were comparable between groups. Robotic-assisted surgery for oncological gastrectomy in elderly patients is safe and effective showing non-inferiority comparing to the open technique in terms of perioperative outcomes and overall 5-year survival
The antitumor drug, 1,3-bis(2-chloroethyl)-1-nitroso-urea, inactivates human nicotinamide mononucleotide adenylyltransferase.
Nicotinamide mononucleotide (NMN) adenylyltransferase (EC 2.7.7.1) from human placenta is rapidly inactivated by 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). A similar inactivation is observed with other C- and N-nitroso compounds. The inactivation by BCNU is dependent on incubation time, temperature and BCNU concentration. Protective reagents for -SH groups, dithiothreitol and beta-mercaptoethanol, and the substrate NMN are very effective in protecting NMN adenylyltransferase from BCNU inactivation and in preserving its catalytic properties, while ATP is less efficient. Incubation of BCNU-inactivated and dialysed NMN adenylyltransferase with dithiothreitol results in a partial recovery of the enzymatic activity
Clinical, magnetic resonance imaging, and histopathologic features of hypothalamic neuronal hamartoma in a young vizsla
Hypothalamic hamartomas (HH) are rare, tumor-like malformations thatoccurduring fetal development and are present at birth. They differ from neoplasms since they are not autonomous and they grow in proportion to normal brain growth, and consequently their relative size to the rest of the brain is the same for the lifetime of the patient. Hamartomas are non-progressive lesions and do not expand, spread or metastasize to other locations. In canine nervous system, vascular, neuronal and peripheral nerve fibers hamartomas have been described; to our knowledge, this is the first report describing the MRI features of a hypothalamic neuronal hamartoma in a dog
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