529 research outputs found
Cyclic Lorentzian Lie Groups
We consider Lie groups equipped with a left-invariant cyclic Lorentzian
metric. As in the Riemannian case, in terms of homogeneous structures, such
metrics can be considered as different as possible from bi-invariant metrics.
We show that several results concerning cyclic Riemannian metrics do not extend
to their Lorentzian analogues, and obtain a full classification of three- and
four-dimensional cyclic Lorentzian metrics
On the symmetries of Siklos spacetimes
We consider the large class of Siklos spacetimes and investigate their relevant symmetries (homothetic and affine vector fields, Ricci, curvature, Weyl and matter collineations). We prove some general results and obtain complete classifications for homogeneous Siklos spacetimes
Pegylated-interferon-α(2a) in clinical practice: how to manage patients suffering from side effects
Introduction: The goal of antiviral therapy in patients with chronic hepatitis C is to slow or halt the progression of fibrosis and prevent the development of cirrhosis. Accordingly, antiviral treatment is proposed for a large population of patients with chronic hepatitis.
Areas covered: The standard-of-care for chronic hepatitis C is the combination of pegylated IFN (PEG-IFN) and ribavirin. The use of these drugs has been correlated with a range of adverse effects, including influenza-like symptoms, hematological changes and neuropsychiatric disturbances. The effects of these adverse events associated with PEG-IFN therapy are manifold and are a major reason why patients decline or stop therapy. This review addresses the screening for adverse event risk factors and guides the patient to success with adherence strategies.
Expert opinion: Knowledge of the side effects correlated with PEG-IFN is very relevant for clinicians because it can allow them to arrange the best methods for treating these effects and avoid the discontinuation of antiviral treatment. Moreover, the use of new antiviral drugs will considerably shorten treatment periods reducing many of the above-described side effects and, thus, increase adherence to scheduled therapy
Litchi chinensis as a Functional Food and a Source of Antitumor Compounds: An Overview and a Description of Biochemical Pathways
Litchi is a tasty fruit that is commercially grown for food consumption and nutritional benefits in various parts of the world. Due to its biological activities, the fruit is becoming increasingly known and deserves attention not only for its edible part, the pulp, but also for its peel and seed that contain beneficial substances with antioxidant, cancer preventive, antimicrobial, and anti-inflammatory functions. Although literature demonstrates the biological activity of Litchi components in reducing tumor cell viability in in vitro or in vivo models, data about the biochemical mechanisms responsible for these effects are quite fragmentary. This review specifically describes, in a comprehensive analysis, the antitumor properties of the different parts of Litchi and highlights the main biochemical mechanisms involved
Multifaceted Health Benefits of Mangifera indica L. (Mango): The Inestimable Value of Orchards Recently Planted in Sicilian Rural Areas
Historically, Mangifera indica L. cultivations have been widely planted in tropical areas
of India, Africa, Asia, and Central America. However, at least 20 years ago its spreading allowed
the development of some cultivars in Sicily, an island to the south of Italy, where the favourable
subtropical climate and adapted soils represent the perfect field to create new sources of production
for the Sicilian agricultural supply chain. Currently, cultivations of Kensington Pride, Keitt, Glenn,
Maya, and Tommy Atkins varieties are active in Sicily and their products meet the requirements
of local and European markets. Mango plants produce fleshy stone fruits rich in phytochemicals
with an undisputed nutritional value for its high content of polyphenolics and vitamins. This review
provides an overview of the antioxidant, anti-inflammatory, and anticancer properties of mango,
a fruit that should be included in everyone\u2019s diet for its multifaceted biochemical actions and
health-enhancing properties
Four-dimensional pseudo-Riemannian homogeneous Ricci solitons
We consider four-dimensional homogeneous pseudo-Riemannian manifolds with
non-trivial isotropy and completely classify the cases giving rise to
non-trivial homogeneous Ricci solitons. In particular, we show the existence of
non-compact homogeneous (and also invariant) pseudo-Riemannian Ricci solitons
which are not isometric to solvmanifolds, and of conformally flat homogeneous
pseudo-Riemannian Ricci solitons which are not symmetric.Comment: 16 pages; Final version, to appear in International Journal of
Geometric Methods in Modern Physic
Enhanced thrombin generation in patients with cirrhosis-induced coagulopathy
BACKGROUND: Prothrombin time (PT) and the international normalized ratio (INR) are still routinely measured in patients with liver cirrhosis to 'assess' their bleeding risk despite the lack of correlation with the two. Thrombin generation (TG) assays are global assays of coagulation that are showing promise in assessing bleeding and thrombosis risks. AIM: To study the relationship between the INR and TG profiles in cirrhosis-induced coagulopathy. METHODS: Seventy-three patients with cirrhosis were studied. All TG parameters were compared with those from a normal control group. Contact activation was prevented using corn trypsin inhibitor. TG was also assayed in the presence of Protac(®). The endogenous thrombin potential (ETP) ratio was derived by dividing the ETP with Protac® by the ETP without Protac®. RESULTS: The INR (mean 1.7) did not correlate with the ETP and the velocity of TG (P > 0.05). There was no difference between the lag time and ETP of the two groups (P > 0.05). The velocity of TG was increased in cirrhosis (67.95 ± 34.8 vs. 45.05 ± 25.9 nM min⁻¹ ; P = 0.016) especially in patients with INRs between 1.21 and 2.0. Both the ETP with Protac(®) and the ETP ratio were increased in cirrhosis (mean 1074 ± 461.4 vs. 818 ± 357.9 nM min, P = 0.004 and 0.80 ± 0.21 vs. 0.44 ± 0.15, P ≤ 0.0001, respectively). CONCLUSION: Despite a raised INR, TG parameters are consistent with a hypercoagulable profile in cirrhosis-related coagulopathy. This confirms that the PT or INR should not be used to assess bleeding risk in these patients, and other parameters, such as TG, need to be explored as clinical markers of coagulopathy
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