Fish populations are globally threatened by overharvesting and habitat degradation. The ability to bank fish embryos by cryopreservation
could be crucial for preserving species diversity, for ...aquaculture (allowing circannual fish farming), and for managing fish
models used in human biomedical research. However, no nonmammalian embryo has ever been successfully cryopreserved. For fish,
low membrane permeability prevents cryoprotectants from entering the yolk to prevent cryodamage. Here, we present evidence
of a membrane mechanism hindering cryopreservation of fish and propose a novel solution to this obstacle. Zebrafish ( Danio rerio ) embryos have rectifying membranes that allow water to leave but not to reenter readily. This feature may be an evolutionary
trait that allows freshwater embryos to grow in hypoosmotic environments without osmoregulatory organs. However, this trait
may also prevent successful fish embryo cryopreservation because both water and cryoprotectants must move into and out of
cells. As a solution, we injected zebrafish embryos with mRNA for the aquaporin-3 water channel protein and demonstrated increased
membrane permeability to water and to a cryoprotectant. Modeling indicates that sufficient cryoprotectant enters aquaporin-3-expressing
zebrafish embryos to allow cryopreservation.
Crotonaldehyde, an αβ-unsaturated aldehyde, and a potent alkylating agent, is present in many foods and beverages, ambient air and tobacco smoke. A previous study indicated that two metabolites, ...3-hydroxy-1- methylpropylmercapturic acid (HMPMA) and 2-carboxy1-1-methylethylmercapturic acid (CMEMA), were excreted in rat urine after subcutaneous injection of crotonaldehyde. Herein, we report the development of a method based on liquid chromatography with tandem mass spectrometry (LC-MS/MS) and deuterated analytes as internal standards, for the determination of HMPMA and CMEMA in human urine. The limits of quantification of the method were 92 and 104 ng/mL for HMPMA and CMEMA, respectively. The calibration curves for both compounds were linear up to 7500 ng/mL with R2 >0.99. It was found that cigarette smokers excreted about three to five-fold more HMPMA, and only slightly elevated amounts of CMEMA, in their urine compared to non-smokers. In smokers, we also found significant correlations between the urinary excretion levels of HMPMA (but not CMEMA) and several markers of exposure for smoking, including the daily cigarette consumption, carbon monoxide in exhaled breath, salivary cotinine, and nicotine plus five of its major metabolites in urine. Smoking cessation or switching from smoking conventional cigarettes to experimental cigarettes with lower crotonaldehyde delivery led to significant reductions of urinary HMPMA excretion, but not CMEMA excretion. Alcohol consumption did not influence either urinary HMPMA or CMEMA excretion. We conclude that HMPMA is a potentially useful biomarker for smoking-related exposure to crotonaldehyde.
Evidence-based psychological treatments (EBPTs) are clusters of interventions, but it is unclear how providers actually implement these clusters in practice. A disaggregated measure of EBPTs was ...developed to characterize clinicians' component-level evidence-based practices and to examine relationships among these practices. Survey items captured components of evidence-based treatments based on treatment integrity measures. The Web-based survey was conducted with 75 U.S. Department of Veterans Affairs (VA) substance use disorder (SUD) practitioners and 149 non-VA community-based SUD practitioners. Clinician's self-designated treatment orientations were positively related to their endorsement of those EBPT components; however, clinicians used components from a variety of EBPTs. Hierarchical cluster analysis indicated that clinicians combined and organized interventions from cognitive-behavioral therapy, the community reinforcement approach, motivational interviewing, structured family and couples therapy, 12-step facilitation, and contingency management into clusters including empathy and support, treatment engagement and activation, abstinence initiation, and recovery maintenance. Understanding how clinicians use EBPT components may lead to improved evidence-based practice dissemination and implementation.
Photographs visually capture experiences within life that are often not captured by language alone. Photography is a powerful tool for understanding human experience and a useful healing strategy. ...When photographs are used as an entree for interviewing participants, stories are elicited and a new view of their lives is revealed. As a person relates the story behind a photograph, new insights emerge about his or her human experience. With photography, other dimensions of observation and knowledge surrounding human experience emerge. This article discusses the use of photography as an aesthetic technique for nursing inquiry. A discussion of the uses of photography within nursing inquiry and suggestions for its use within method are presented.
Background: Attempts to modify traditional fluid resuscitation have been based on animal models that evaluate several variables including anesthesia. This study presents the effects of early saline ...resuscitation from severe uncontrolled hemorrhage in unanesthetized rats.
Methods: Sixty-three female Sprague-Dawley rats were equally divided into three groups: group A, nonresuscitated; and groups B and C, resuscitated with isotonic saline (40 and 80 mL/kg, respectively). Hemodynamics, blood loss, survival time, and mortality were recorded for 360 minutes after the hemorrhage, which was initiated by 75% resection of the tail.
Results: In group C, 80 mL/kg of saline significantly lowered mortality (24% vs 76% and 71% for groups A and B, respectively) with concomitant increases in mean survival time (241 ± 103 min vs 146 ± 108 and 175 ± 92 min for groups A and B, respectively). There were no statistically significant differences in blood loss, hematocrit, or hemodynamic parameters among the groups.
Conclusions: Early and adequate isotonic saline resuscitation of unanesthetized rats improved outcome despite continuing hemorrhage. The significantly lower mortality rate and increased survival time were not a result of transiently improved arterial pressure and did not correlate with blood loss. No significant bleeding increases were noted in the resuscitated groups. (Surgery 1998;124:568-74.)
In this work, we have experimentally and by simulations investigated the effect of making small perturbations of the size of the border holes adjacent to the planar photonic crystal waveguide (PCW). ...The waveguide is created by removing one row of holes in the nearest-neighbour direction of air holes placed on a triangular lattice with pitch Lambda=380 nm in a silicon-on-insulator (SOI) material
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