Self-nucleation of isotactic poly(1-butene) in the trigonal modification

Isotactic poly(1-butene) (i-PBu) is a polyolefin of industrial relevance which exhibits an interesting polymorphism. Upon cooling from the relaxed melt at atmospheric pressure, a tetragonal phase (Form II) develops. However, being metastable, this structure slowly evolves upon aging in the stable trigonal modification (Form I). Another trigonal modification, denoted Form I′, can also crystallize directly from the melt if proper conditions are met, e.g., high pressure, low tacticity, ultrathin samples etc. In this work, we aim to verify whether, by acting on the nucleation stage via a proper thermal history, the direct formation of the trigonal polymorph from the melt in a bulk sample is possible. Nucleation of i-PBu has been tailored by means of the self-nucleation technique, imposed on previously aged samples (Form I). DSC and temperature-resolved WAXS show that different crystallization pathways can be observed, depending on the residual concentration of Form I self-nuclei. With decreasing self-nucleation temperature we first encounter “cross-nucleation” of the tetragonal crystal on trigonal nuclei, followed by concomitant crystallization of Form II and Form I′ and eventually the sole formation of the trigonal modification (Form I′).     

The Role of Testosterone in the Elderly: What Do We Know?

Testosterone is the most important hormone in male health. Aging is characterized by testosterone deficiency due to decreasing testosterone levels associated with low testicular production, genetic factors, adiposity, and illness. Low testosterone levels in men are associated with sexual dysfunction (low sexual desire, erectile dysfunction), reduced skeletal muscle mass and strength, decreased bone mineral density, increased cardiovascular risk and alterations of the glycometabolic profile. Testosterone replacement therapy (TRT) shows several therapeutic effects while maintaining a good safety profile in hypogonadal men. TRT restores normal levels of serum testosterone in men, increasing libido and energy level and producing beneficial effects on bone density, strength and muscle as well as yielding cardioprotective effects. Nevertheless, TRT could be contraindicated in men with untreated prostate cancer, although poor findings are reported in the literature. In addition, different potential side effects, such as polycythemia, cardiac events and obstructive sleep apnea, should be monitored. The aim of our review is to provide an updated background regarding the pros and cons of TRT, evaluating its role and its clinical applicability in different domains.     

Influence of genotype,harvest time and plant part on polyphenolic composition of globe artichoke [Cynara cardunculus L. var. scolymus (L.) Fiori]

Globe artichoke is an ancient herbaceous plant native to the Mediterranean Basin. The edible part of the plant (head) is particularly rich in polyphenols, whose therapeutic properties are well documented. A field experiment was conducted in Sicily (south Italy) to examine the influence of genotype and harvest time on the polyphenol content and profile of different head parts. The concentrations of 19 phenolic compounds were determined by HPLC-DAD-ESI/MSⁿ analysis. It was observed that individual phenolic substances were preferentially accumulated in specific head parts and genotypes. Apigenin 7-O-glucuronide was found to be the major flavonoid, with 6298 mg kg⁻¹ DM in ‘Romanesco clone C3’ receptacle, whereas chlorogenic acid represented the main caffeoylquinic acid, reaching 14841 mg kg⁻¹ DM in the inner bracts of ‘Violetto di Sicilia’. Our findings prove also the influence of climatic conditions on the phenolic profile and thus suggest giving specific consideration to harvest time.     

Cholesterol photosensitised oxidation of horse meat slices stored under different packaging films

The effect of the type of packaging film (transparent vs. light-protecting red film) was evaluated on the formation of cholesterol oxidation products (COPs) in refrigerated horse meat slices stored in retail conditions under light exposure for 8 h. In meat wrapped with a transparent film, COPs increased from 233 (control) to 317 μg/g of fat, whereas the red film delayed cholesterol oxidation and offered protection against COPs formation, since COPs decreased from 173 (control) to 139 μg/g of fat after 8 h of light exposure. In addition, light opened the epoxy ring and led to the formation of triol, which was actually absent at T_0. A proper packaging film may represent a useful strategy to retard oxidative degradation in a light-sensitive, high pigment- and fat-containing food, such as horse meat.     

Association of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) with age of puberty among children living near a chemical plant

Animal studies suggest that perfluorocarbons (PFCs) may alter sexual maturation. Relationships of human PFC exposure with puberty are not clear. We conducted a cross-sectional study to investigate whether perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) were associated with indicators of sexual maturation in a 2005-2006 survey of residents with PFOA water contamination from the Mid-Ohio Valley. Participants were 3076 boys and 2931 girls aged 8-18 years. They were classified as having reached puberty based on either hormone levels (total >50 ng/dL and free >5 pg/mL testosterone in boys and estradiol >20 pg/mL in girls) or onset of menarche. We estimated the odds of having reached puberty classified by these criteria and the fitted median age of reaching puberty in relation to serum PFOA and PFOS concentrations measured when puberty status was assigned. For boys, there was a relationship of reduced odds of reached puberty (raised testosterone) with increasing PFOS (delay of 190 days between the highest and lowest quartile). For girls, higher concentrations of PFOA or PFOS were associated with reduced odds of postmenarche (130 and 138 days of delay, respectively). In conclusion, our study showed a later age of puberty in this population correlated with PFC concentrations.     

Electrical energy metering: Some challenges of the European Directive on Measuring Instruments (MID)

The introduction of static electric energy meter together with voltage and current distortions in the electric networks are revolutionizing the measurement of the electrical energy. Several questions and studies are proposed in the scientific literature concerning with metrological and reliability aspects of the actual electrical energy measurement. The European Directive on Measuring Instruments (MID) represents a different spin on setting the performance and safety requirements for those meters. The International Organization of Legal Metrology (OIML) has published the document D11 discussing recommendations for legislation to meet the MID. An OIML technical committee is drafting the recommendation (IR46) that would give regulatory bodies an easily-adoptable set of requirements and tests to meet the requirements of the MID. With the introduction of the MID directive, the actual discussion involves aspects as the metrological characterization of the meters. The paper proposes an analysis of the test settings imposed by the actual MID-harmonized standards, regarding the electric energy metering. The aim is to check the presence of degree of freedom in the test settings that could compromise both result reliability and the compliance/non-compliance of a given apparatus.     

Antioxidant activity,color chromaticity coordinates,and chemical characterization of monofloral honeys from Morocco

The bioprospecting of several monofloral Moroccan honeys was carried out. The antiradical activity expressed as mmol Trolox equivalents/kg of honey and evaluated by 2,2-diphenyl-1-picrylhydrazyl assay, ranged from 0.15 for euphorb honey to 1.08 for citrus honey. The antioxidant activity expressed as mmol Fe²⁺/kg and evaluated by ferric ion reducing antioxidant power assay, ranged from 0.96 for euphorb honey to 4.74 for orange honey. The total phenol content was evaluated by colorimetric assay, while the color attributes were evaluated as transmittance data. Significant Pearson correlation factors were found between total polyphenol amount and antioxidant activity and between color attributes and antioxidant activity. Furthermore the chemical composition of volatile organic compounds was determined. The volatile organic compounds chemical composition of the studied honeys was mainly represented by terpene and benzene derivatives, Maillard reaction products, isoprenoids, and hydrocarbons. The volatiles fingerprint, as well as a targeted high-performance liquid chromatography analysis of the polar components, was used to tentatively confirm the declared botanical origin of the samples studied.     

Potent,Metabolically Stable 2‐Alkyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐adenines as Adenosine A2A Receptor Ligands

Inhibition of adenosine A_2A receptors has been shown to elicit a therapeutic response in preclinical animal models of Parkinson’s disease (PD). We previously identified the triazolo‐9H‐purine, ST1535, as a potent A_2AR antagonist. Studies revealed that ST1535 is extensively hydroxylated at the ω‐1 position of the butyl side chain. Here, we describe the synthesis and evaluation of derivatives in which the ω‐1 position has been substituted (F, Me, OH) in order to block metabolism. The stability of the compounds was evaluated in human liver microsomes (HLM), and the affinity for A_2AR was determined. Two compounds, (2‐(3,3‐dimethylbutyl)‐9‐methyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐purin‐6‐amine ( 3 b ) and 4‐(6‐amino‐9‐methyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐purin‐2‐yl)‐2‐methylbutan‐2‐ol ( 3 c ), exhibited good affinity against A_2AR (K_i=0.4 nM and 2 nM , respectively) and high in vitro metabolic stability (89.5 % and 95.3 % recovery, respectively, after incubation with HLM for two hours).