Now showing items 1-10 of 22
Menopause, A Universal Female Experience: Lessons from Mexico and Central America
(Current Women’s Health Reviews 4(1), 3-8, 2008)
In Mexico and Central America, women typically experience menopause up to 10 years earlier than their U.S. counterparts. This may be due in part to numerous pregnancies, long periods of lactation, poor nutrition, extreme ...
Efficient syntheses of streptocarpone and (±)-a-dunnione
An efficient divergent synthesis of both streptocarpone and racemic α-dunnione from lawsone are described. A one-pot, formal [3+2] cyclization to form a furanonaphthoquinone directly provided a common intermediate.
Light Reflection by Cuticles of Chrysina Jewel Scarabs: Optical Measurements, Morphology Characterization, and Theoretical Modeling
Cuticles of some Chrysina scarabs are characterized by flat, graded, and twisted structures of nanosized chitin fibrils. As inferred from SEM images, each species has its own spatial period or pitch P which is dependent ...
Richness of cultivable endophytic fungi along an altitudinal gradient in wet forests of Costa Rica
We collected various plant species along an altitudinal gradient ranging from 400 to 2900 m in tropical wet forests of Costa Rica, isolated the associated endophytic fungi, and performed bioinformatic analyses to determine ...
Interplay of the PtsN (EIIANtr) protein of Pseudomonas putida with its target sensor kinase KdpD
The nitrogen phosphotransferase system (PTSNtr) of Pseudomonas putida is a multi-component regulatory device that participates in controlling a variety of physiological processes in a post-translational fashion. A general ...
Brachiopods, sipunculans, enteropneusts and metals from two estuarine tidal flats, Pacific, Costa Rica
Braquiópodos, sipuncúlidos, enteropneustos y metales en dos planicies estuarinas de marea, Pacífico, Costa Rica.
Reports on the abundances and on metal concentrations in intertidal estuarine invertebrates from the Eastern Tropical Pacific are rare. Thus, the objectives of this report are to make accessible data on the abundances ...
Synthesis of Iodinated Naphthoquinones Using Morpholine-Iodine Complex
(Synthetic Communications Vol. 34, No. 18, pp. 3389–3397, 2004, 2004)
The efficient synthesis of 2‐hydroxy‐3‐iodo‐1,4‐naphthoquinone (3), 2‐amino‐3‐iodo‐1,4‐naphthoquinone (4), and 2‐iodo‐1,4‐naphthoquinone (5) have been developed using the parent naphthoquinone in combination with the ...
Metals in coastal mollusks of Costa Rica
Metales en moluscos costeros de Costa Rica
The input of contaminants to coastal ecosystems is a global problem on the rise. Data on metal pollution from tropical sites is often lacking and pilot surveys are urgently needed to provide a general framework to estimate ...
Mastering analytical challenges for the characterization of pentacyclic triterpene mono- and diesters of Calendula officinalis flowers by non-aqueous C30 HPLC and hyphenation with APCI-QTOF-MS
Pentacyclic triterpene mono- and diesters have been isolated from Calendula officinalis flowers. GC–MS, APCI-Exactive Orbitrap HR-MS and NMR allowed to identify the triterpene skeleton in various samples (different triterpene ...
Pristine but metal-rich Río Sucio (Dirty River) is dominated by Gallionella and other iron-sulfur oxidizing microbes
Whether the extreme conditions of acidity and heavy metal pollution of streams and rivers originating in pyritic formations are caused primarily by mining activities or by natural activities of metal-oxidizing microbes ...