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2.
Int J Parasitol Parasites Wildl ; 24: 100965, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39132512

RESUMEN

The detection of severe limb malformations in metamorphosing northern leopard frogs (Rana pipiens) from a Colorado pond in August 2022 prompted questions about the cause(s) and concern over the implications. Northern leopard frogs, which are a Tier 1 Species of Greatest Conservation Need in Colorado, have declined over much of their range in the state, particularly along the Front Range. Although malformations in amphibians have been reported in other parts of the USA, they are rare in Colorado, and the current case represents the most severe hotspot reported in the state for over 70 years. Across three survey events in late summer and early fall of 2022, approximately 68% of captured leopard frogs (late-stage larvae and metamorphic frogs) exhibited one or more malformations. Malformations exclusively affected the hind limbs and were dominated by skin webbings (51.7% of the total), bony triangles (32.2%), and extra limbs or digits (11%). Many animals had multiple malformations that limited the movement of one or both limbs (average of 2.3 malformations per malformed frog). Dissection of a subset of animals coupled with 28S rDNA genetic sequencing revealed the occurrence of the trematode Ribeiroia ondatrae at an average of 75.2 trematode cysts (metacercariae) per frog. The parasite was also detected in 2.6% of dissected snails (Helisoma trivolvis), which function as the trematode's first intermediate host. The relatively high loads of infection detected here - coupled with the similarity of observed malformations to those previously linked to R. ondatrae in experimental studies and from other malformation hotspots in the USA - offer compelling evidence that the current case is the result of parasite infection. Unresolved questions include why malformation prevalence was so high in 2022 and the degree to which such abnormalities will affect population persistence for local leopard frogs, particularly if malformations continue.

3.
JBMR Plus ; 8(5): ziae019, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38634075

RESUMEN

Understanding the genetic basis of cortical bone traits can allow for the discovery of novel genes or biological pathways regulating bone health. Mice are the most widely used mammalian model for skeletal biology and allow for the quantification of traits that cannot easily be evaluated in humans, such as osteocyte lacunar morphology. The goal of our study was to investigate the effect of genetic diversity on multi-scale cortical bone traits of 3 long bones in skeletally-mature mice. We measured bone morphology, mechanical properties, material properties, lacunar morphology, and mineral composition of mouse bones from 2 populations of genetic diversity. Additionally, we compared how intrabone relationships varied in the 2 populations. Our first population of genetic diversity included 72 females and 72 males from the 8 inbred founder strains used to create the Diversity Outbred (DO) population. These 8 strains together span almost 90% of the genetic diversity found in mice (Mus musculus). Our second population of genetic diversity included 25 genetically unique, outbred females and 25 males from the DO population. We show that multi-scale cortical bone traits vary significantly with genetic background; heritability values range from 21% to 99% indicating genetic control of bone traits across length scales. We show for the first time that lacunar shape and number are highly heritable. Comparing the 2 populations of genetic diversity, we show that each DO mouse does not resemble a single inbred founder, but instead the outbred mice display hybrid phenotypes with the elimination of extreme values. Additionally, intrabone relationships (eg, ultimate force vs. cortical area) were mainly conserved in our 2 populations. Overall, this work supports future use of these genetically diverse populations to discover novel genes contributing to cortical bone traits, especially at the lacunar length scale.

4.
bioRxiv ; 2023 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-37333124

RESUMEN

Understanding the genetic basis of cortical bone traits can allow for the discovery of novel genes or biological pathways regulating bone health. Mice are the most widely used mammalian model for skeletal biology and allow for the quantification of traits that can't easily be evaluated in humans, such as osteocyte lacunar morphology. The goal of our study was to investigate the effect of genetic diversity on multi-scale cortical bone traits of three long bones in skeletally-mature mice. We measured bone morphology, mechanical properties, material properties, lacunar morphology, and mineral composition of mouse bones from two populations of genetic diversity. Additionally, we compared how intra-bone relationships varied in the two populations. Our first population of genetic diversity included 72 females and 72 males from the eight Inbred Founder strains used to create the Diversity Outbred (DO) population. These eight strains together span almost 90% of the genetic diversity found in mice (Mus musculus). Our second population of genetic diversity included 25 genetically unique, outbred females and 25 males from the DO population. We show that multi-scale cortical bone traits vary significantly with genetic background; heritability values range from 21% to 99% indicating genetic control of bone traits across length scales. We show for the first time that lacunar shape and number are highly heritable. Comparing the two populations of genetic diversity, we show each DO mouse does not resemble a single Inbred Founder but instead the outbred mice display hybrid phenotypes with the elimination of extreme values. Additionally, intra-bone relationships (e.g., ultimate force vs. cortical area) were mainly conserved in our two populations. Overall, this work supports future use of these genetically diverse populations to discover novel genes contributing to cortical bone traits, especially at the lacunar length scale.

5.
ACS Appl Mater Interfaces ; 5(20): 10221-6, 2013 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-24073919

RESUMEN

Superamphiphobic coatings with excellent repellency to low surface tension liquids and multiple self-healing abilities are very useful for practical applications, but remain challenging to realize. Previous papers on self-healing superamphiphobic coatings have demonstrated limited liquid repellency with single self-healing ability against either physical or chemical damage. Herein, we describe a superamphiphobic fabric that has remarkable multi-self-healing ability against both physical and chemical damages. The superamphiphobicity was prepared by a two-step surface coating technique. Fabric after coating treatment showed exceptional liquid-repellency to low surface tension liquids including ethanol. The fabric coating was also durable to withstand 200 cycles of laundries and 5000 cycles of Martindale abrasion without apparently changing the superamphiphobicity. This highly robust, superamphiphobic fabric may find applications for the development of "smart" functional textiles for various applications.

6.
Adv Mater ; 24(18): 2409-12, 2012 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-22488898

RESUMEN

A superhydrophobic fabric coating made of a crosslinked polydimethylsiloxane elastomer, containing well-dispersed hydrophobic silica nanoparticles and fluorinated alkyl silane, shows remarkable durability against repeated machine washes, severe abrasion, strong acid or base, boiling water or beverages and excellent stain resistance.


Asunto(s)
Nanopartículas/química , Silanos/química , Dióxido de Silicio/química , Elastómeros de Silicona/química , Dimetilpolisiloxanos/química , Flúor/química , Interacciones Hidrofóbicas e Hidrofílicas
7.
Nano Lett ; 10(3): 838-46, 2010 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-20170193

RESUMEN

Low efficiencies and costly electrode materials have limited harvesting of thermal energy as electrical energy using thermo-electrochemical cells (or "thermocells"). We demonstrate thermocells, in practical configurations (from coin cells to cells that can be wrapped around exhaust pipes), that harvest low-grade thermal energy using relatively inexpensive carbon multiwalled nanotube (MWNT) electrodes. These electrodes provide high electrochemically accessible surface areas and fast redox-mediated electron transfer, which significantly enhances thermocell current generation capacity and overall efficiency. Thermocell efficiency is further improved by directly synthesizing MWNTs as vertical forests that reduce electrical and thermal resistance at electrode/substrate junctions. The efficiency of thermocells with MWNT electrodes is shown to be as high as 1.4% of Carnot efficiency, which is 3-fold higher than for previously demonstrated thermocells. With the cost of MWNTs decreasing, MWNT-based thermocells may become commercially viable for harvesting low-grade thermal energy.


Asunto(s)
Suministros de Energía Eléctrica , Electroquímica/instrumentación , Nanotecnología/instrumentación , Nanotubos de Carbono/química , Cristalización/métodos , Transferencia de Energía , Diseño de Equipo , Análisis de Falla de Equipo , Calor , Ensayo de Materiales , Nanotubos de Carbono/ultraestructura , Tamaño de la Partícula
8.
J Biomed Mater Res B Appl Biomater ; 82(1): 37-43, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17078076

RESUMEN

Carbon nanotubes present a new material for the construction of electrodes for electrochemical devices such as batteries, capacitors, and actuators. Such electrodes require high conductivity, strength, and surface area. The latter two requirements are often incompatible. Electrodes composed entirely of carbon nanotubes (bucky paper) have high surface areas but are typically weak, and have insufficient conductivity for practical macroscopic applications. Here we report a technique that uses naturally occurring biopolymers to produce electrodes (free standing films) that exhibit conductivities of 300 S/cm. These composites also have considerable mechanical strength (up to 145 MPa) and sufficient specific capacitance of 19-27 F/g to enable them to be used as freestanding electrodes. One potential application that deserves special attention is that of biocompatible electrodes, where the binder is a biopolymer already used in a range of implants. Preliminary studies reported here show that the new carbon nanotube biopolymer electrodes can foster prolific L929 cell growth.


Asunto(s)
Quitosano/química , ADN de Cadena Simple/química , Microelectrodos , Nanotubos de Carbono/química , Animales , Biopolímeros/química , Línea Celular , Proliferación Celular , Capacidad Eléctrica , Ratones
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