Natural Products from Annonaceae as Potential Antichagasic Agents

Chagas disease, a neglected tropical disease, is endemic in 21 Latin American countries and particularly prevalent in Brazil. Chagas disease has drawn more attention in recent years due to its expansion into non-endemic areas. The aim of this work was to computationally identify and experimentally validate the natural products from an Annonaceae family as antichagasic agents. Through the ligand-based virtual screening, we identified 57 molecules with potential activity against the epimastigote form of T. cruzi. Then, 16 molecules were analyzed in the in vitro study, of which, six molecules displayed previously unknown antiepimastigote activity. We also evaluated these six molecules for trypanocidal activity. We observed that all six molecules have potential activity against the amastigote form, but no molecules were active against the trypomastigote form. 13-Epicupressic acid seems to be the most promising, as it was predicted as an active compound in the in silico study against the amastigote form of T. cruzi, in addition to having in vitro activity against the epimastigote form.     

Direct and Enantioselective Vinylogous Michael Addition of α‐Alkylidenepyrazolinones to Nitroolefins Catalyzed by Dual Cinchona Alkaloid Thioureas

While several protocols exist for the asymmetric functionalization of pyrazolinones at the α‐position relying on nucleophilic addition or annulation procedures, use of α‐alkylidene electron‐rich analogues in asymmetric vinylogous coupling to carbon electrophiles is substantially an uncharted domain. We now report, for the first time, that alkylidenepyrazolinones carrying an enolizable carbon at the γ‐position efficiently participate in direct and asymmetric, catalytic vinylogous Michael‐type additions to nitroolefins providing the expected adducts in high yields, with complete γ‐site selectivity and with extraordinary levels of enantio‐, diastereo‐, and geometrical selectivities. Both enantiomeric adducts were equally accessed by employing a quasi‐enantiomeric quinine‐ or quinidine‐based thiourea catalyst pair.

     

Aqueous and Solvent‐Free Uncatalyzed Three‐Component Vinylogous Mukaiyama–Mannich Reactions of Pyrrole‐Based Silyl Dienolates

A catalyst‐free, environmentally benign three‐component vinylogous Mukaiyama–Mannich reaction of pyrrole‐based silyl dienolates is presented, which works effectively in both aqueous and solvent‐free environments. Both lipophilic and hydrophilic aldehyde candidates are suitable substrates, allowing access to a rich repertoire of unsaturated vicinal aminolactam structures with virtually complete γ‐site selectivity and moderate to good anti‐diastereoselectivity. The utility of this technology is highlighted by protecting group‐free synthesis of densely hydroxylated, sugar‐related lactam frameworks. The role of water as an indispensable H‐bonding reaction propeller is demonstrated.     

Space anthropology: physical and cultural adaptation in outer space

Humans are the product of biologic and cultural adaptation to our Planet achieved over million years of Primates and Hominids species evolution which has led us to a specific development of intelligence, speech, and manual capability. Interface usability mainly depends on human characteristics that are also modified by variations in the environment. In outer space, body shapes may be different, things may not be in the expected place and models of conventional social relationships may be hardly transferred to prolonged missions. The process known as exaptation, according to which traits developed by a species as a response to a specific need are later “recycled” with new functions in a different environment, will be considered. Biologic and cultural built-in mechanisms belonging to our past cannot be left out in the analysis of design and man–machine interface in the Outer Space.     

BIXIN POWDER PRODUCTION IN CONICAL SPOUTED BED UNITS

Recent work has demonstrated that the red carotenoid bixin is easily extracted from Bixa orellana seeds by particle attrition and impact rather than by solvent extraction. This technique may require a previous step for drying seeds at a safe temperature to preserve pigment quality. A spouted bed (SB) with a draft tube is the most appropriate equipment to process both seed drying and bixin extraction at low operational costs. Operational parameters of the SB unit are optimized as a function of the powder production rate. The maximum air inlet temperature for drying the seeds is also specified. A high performance liquid chromatography method has been developed for the semi-quantitative determination of bixin content in the powder produced. Results show that this SB unit can be more competitive than ball mill equipment.     

Attention and reaction to distress in infancy: A longitudinal study.

The primary aim of this study was to verify whether early individual differences in look duration are related to general mechanisms of the infant nervous system that draw together attention and emotion. Thirty-one infants were observed at 3, 5, and 11 months of age. Facial expressions of pain and distress were observed by means of C. Izard's (1979) Maximally Discriminative Facial Movement Coding System 90 s after routine pediatric vaccinations. Several measures of visual attention were taken experimentally in a separate testing session. Significant correlations between measures of attention and duration of facial expressions of pain and distress were found at each age level. Infants who showed pain or distress for a shorter time period also paid attention for a shorter time period and vice versa. The main conclusion is that individual differences combining control of both pain and attention can be identified from early infancy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Liver transplantation for small hepatocellular carcinoma: the tumor-node-metastasis classification does not have prognostic power

Tumoral recurrence rate and survival of patients with hepatocellular carcinoma (HCC) treated by orthotopic liver transplantation (OLT) depend on tumor stage. Thereby, from the beginning of our program, we selected only patients with solitary tumors < or = 5 cm without vascular invasion, thus avoiding the use of the tumor-node-metastasis (TNM) staging system as a selection tool. The present study reports the results obtained in 58 consecutive patients (52 +/- 8 years, 47 males) with HCC (7 incidentals) transplanted between 1989 and 1995. Transplantation was indicated because of tumor diagnosis in 40 cases and advanced liver failure in 18. Mean tumor size at staging was 28.2 +/- 12.1 mm. No adjuvant treatment was applied during the waiting period (58.9 +/- 45.1 days). The pathological tumor-node-metastasis (pTNM) classification allocated 15 patients to stage I, 19 to stage II, 11 to stage IIIA, and 13 to stage IVA showing preoperative understaging in 43% of the cases with known tumor. After a median follow up of 31 months, only two patients have shown tumor recurrence and fifteen have died, the 1-, 3-, and 5-year survival being 84%, 74%, and 74%. All HCV+ patients remain infected and 94% showed significant liver disease (6 cirrhosis). Six patients have had a second transplant. In conclusion, the application of restrictive criteria not following the TNM staging system prompts excellent results for liver transplantation in patients with HCC, both in terms of survival and disease recurrence, even without applying adjuvant treatment; however, the survival data should be tempered by the appearance of complications that may worsen the long-term prognosis.     

An I/Q mismatch-free switched-capacitor complex sigma-delta Modulator

This paper presents a technique to suppress the mismatch between the in-phase (I) and quadrature-phase (Q) channels of a switched-capacitor complex sigma-delta modulator that is used for the analog-to-digital conversion of a real intermediate-frequency radio signal. The mismatch is suppressed through time sharing of the critical capacitors, i.e., the input sampling capacitor and the capacitor of the feedback digital-to-analog converter, between the I and Q channels. Circuit simulations verifying the proposed technique are presented.