Ultrasound, photoacoustic, and magnetic resonance imaging to study hyperacute pathophysiology of traumatic and vascular brain injury.

BACKGROUND AND PURPOSE: Cerebrovascular dynamics and pathomechanisms that evolve in the minutes and hours following traumatic vascular injury in the brain remain largely unknown. We investigated the pathophysiology evolution in mice within the first 3 hours after closed-head traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH), two significant traumatic vascular injuries. METHODS: We took a multimodal imaging approach using photoacoustic imaging, color Doppler ultrasound, and MRI to track injury outcomes using a variety of metrics. RESULTS: Brain oxygenation and velocity-weighted volume of blood flow (VVF) values significantly decreased from baseline to 15 minutes after both TBI and SAH. TBI resulted in 19.2% and 41.0% ipsilateral oxygenation and VVF reductions 15 minutes postinjury, while SAH resulted in 43.9% and 85.0% ipsilateral oxygenation and VVF reduction (p < .001). We found partial recovery of oxygenation from 15 minutes to 3 hours after injury for TBI but not SAH. Hemorrhage, edema, reduced perfusion, and altered diffusivity were evident from MRI scans acquired 90-150 minutes after injury in both injury models, although the spatial distribution was mostly focal for TBI and diffuse for SAH. CONCLUSIONS: The results reveal that the cerebral oxygenation deficits immediately following injuries are reversible for TBI and irreversible for SAH. Our findings can inform future studies on mitigating these early responses to improve long-term recovery.

Dietary Intake Correlated to Waist-To-Hip Ratio in Patients on Maintenance Hemodialysis.

OBJECTIVE: Individuals with end-stage kidney disease (ESKD) receiving maintenance hemodialysis (MHD) are at risk for protein-energy wasting (PEW). Inadequate dietary intake and altered anthropometrics are two criteria of the PEW diagnosis. This study explored whether individuals with ESKD on MHD meet the National Kidney Foundation Kidney Disease Outcome Quality Initiative (NKF-KDOQI) 2020 guidelines for nutritional adequacy on a dialysis treatment day (DD) and explored the relationship between dietary energy [DEI] and protein [DPI] intake and anthropometrics. METHODS: This was a secondary analysis of clinical and demographic data for 142 adults from the Rutgers Nutrition and Kidney Disease database. The study assessed the relationships between DEI, DPI, and anthropometrics, including body mass index (BMI), BMI category, waist circumference, and waist-to-hip ratio (WHR) using Pearson's or Spearman's correlation and one-way ANOVA. RESULTS: The sample had a median age of 55.7 years; 58% were male, 83.8% were Black/African American, with a median dialysis vintage of 42.0 months (e.g., 3.5 years). Seventy-five percent of the data sample were overweight or obese. The WHR was 1.0 ± 0.8 cm for males and 0.9 ± 0.1 for females. DEI and DPI on a DD did not meet the NKF-KDOQI 2020 guidelines. Median DEI was 17.6 ± 8.4 kcal/kg and DPI was 0.7 ± 0.4 g/kg. In the total sample, significant positive correlations were found between DEI (r = 0.74, P = 0.03) and DPI (r = 0.18, P = 0.037) and WHR. In females, a significant positive correlation was identified between DPI and WHR (r = 0.26, P = 0.046). CONCLUSIONS: These findings suggest that the nutritional intake of individuals with ESKD receiving MHD is inadequate to meet NKF-KDOQI 2020 guidelines on a DD. WHR may be a useful tool to assess alterations in anthropometrics related to DEI or DPI in this population, but more research is warranted.

Metabolic and physical function are improved with lifelong 15% calorie restriction in aging male mice.

Chronic calorie restriction (CR) results in lengthened lifespan and reduced disease risk. Many previous studies have implemented 30-40% calorie restriction to investigate these benefits. The goal of our study was to investigate the effects of calorie restriction, beginning at 4 months of age, on metabolic and physical changes induced by aging. Male C57BL/6NCrl calorie restricted and ad libitum fed control mice were obtained from the National Institute on Aging (NIA) and studied at 10, 18, 26, and 28 months of age to better understand the metabolic changes that occur in response to CR in middle age and advanced age. Food intake was measured in ad libitum fed controls to assess the true degree of CR (15%) in these mice. We found that 15% CR decreased body mass and liver triglyceride content, improved oral glucose clearance, and increased all limb grip strength in 10- and 18-month-old mice. Glucose clearance in ad libitum fed 26- and 28-month-old mice is enhanced relative to younger mice but was not further improved by CR. CR decreased basal insulin concentrations in all age groups and improved insulin sensitivity and rotarod time to fall in 28-month-old mice. The results of our study demonstrate that even a modest reduction (15%) in caloric intake may improve metabolic and physical health. Thus, moderate calorie restriction may be a dietary intervention to promote healthy aging with improved likelihood for adherence in human populations.

Functional Status and Engagement in Physical Activity Among Maintenance Dialysis Patients: A Mixed Methods Study.

Rationale & Objective: People receiving maintenance hemodialysis (HD) experience significant activity barriers but desire the ability to do more and remain independent. To learn about how to help people who require dialysis stay active, a mixed methods study was designed to assess functional status and explore participants' lived activity experiences. Study Design: A concurrent mixed methods design was chosen to increase understanding of the real-life activity experiences of people who require dialysis through in-depth interviews paired with functional status measures. The qualitative findings were fully integrated with the quantitative results to link characteristics associated with different physical activity levels. Setting & Participants: A purposive sample of 15 adult patients receiving maintenance HD for at least 3 months was recruited from 7 dialysis centers in Newark, New Jersey. Analytical Approach: Thematic analysis using principles of interpretive phenomenology. Fully integrated quantitative and qualitative data with joint displays and conversion mixed methods. Results: Participants had a median age of 58 years and were predominantly African American (83%) and men (67%). Three descriptive categories were generated about the participants. They described physical activity as a routine daily activity rather than structured exercise. All participants experienced substantial hardship in addition to chronic kidney disease and expressed that family, friends, and faith were essential to their ability to be active. An overarching theme was generated for participants' mindsets about physical activity. Within the mindset theme, we discerned 3 subthemes comprising characteristics of participants' mindsets by levels of engagement in physical activity. Limitations: While code saturation and trends in functional status measures were achieved with 15 participants, a larger sample size would allow for deeper meaning saturation and statistical inference. Conclusions: Patients receiving maintenance HD with an engaged mindset exhibited more adaptive coping skills, moved more, wanted to help others, and had a normal body weight habitus. These participants employed adaptive coping skills to carry out daily life activities of importance, highlighting the value of adaptive coping to help overcome the challenges of being physically active.

Current methods for developing predictive energy equations in maintenance dialysis are imprecise.

PURPOSE: For individuals receiving maintenance dialysis, estimating accurate resting energy expenditure (REE) is essential for achieving energy balance, and preventing protein-energy wasting. Dialysis-specific, predictive energy equations (PEEs) offer a practical way to calculate REE. Three PEEs have been formulated via similar methods in different demographic samples; the Maintenance Haemodialysis Equation (MHDE REE), Vilar et al. Equation (Vilar REE) and the Fernandes et al. Equation (Cuppari REE). We compared them in a US cohort and assessed precision relative to measured REE (mREE) from indirect calorimetry. Because of expected imprecision at the extremes of the weight distribution, we also assessed the PEEs stratified by body mass index (BMI) subgroups. METHODS: This analysis comprised of 113 individuals from the Rutgers Nutrition and Kidney Database. Estimated REE (eREE) was calculated for each PEE, and agreement with mREE was set at > 50% of values within the limits of ±10%. Reliability and accuracy were determined using intraclass correlation (ICC) and a Bland Altman plot, which analysed the percentage difference of eREE form mREE. RESULTS: Participants were 58.4% male and 81.4% African American. Mean age was 55.8 ± 12.2 years, and the median BMI was 28.9 (IQR = 25.3 - 34.4) kg/m2. The MHDE REE achieved 58.4% of values within ±10% from mREE; Cuppari REE achieved 47.8% and Vilar REE achieved 46.0% agreement. Reliability was good for the MHDE REE (ICC = 0.826) and Cuppari REE (ICC = 0.801), and moderate for the Vilar REE (ICC = 0.642) (p < .001 for all). The equations performed poorly at the lowest and highest BMI categories. CONCLUSION: Dialysis-specific energy equations showed variable accuracy. When categorized by BMI, the equations performed poorly at the extremes, where individuals are most vulnerable. Innovation is needed to understand these variances and correct the imprecision in PEEs for clinical practice.KEY MESSAGESPotentially impacting over millions of patients worldwide, our long-term goal is to understand energy expenditure (EE) across the spectrum of CKD (stages 1-5) in adults and children being treated with dialysis or transplantation, with the intent of providing tools for the health professional that will improve the delivery of quality care.Our research has identified and focussed on disease-specific factors which account for 60% of the variance in predicting EE in patients on MHD, but significant gaps remain.Thus, our central hypotheses are that (1) there are unique disease-specific determinants of EE and (2) prediction of EE for individuals diagnosed with CKD can be vastly improved with a model that combines these factors with more sophisticated approaches.

Amyloid-ß disrupts unitary calcium entry through endothelial NMDA receptors in mouse cerebral arteries.

Transient increases in intracellular Ca2+ activate endothelium-dependent vasodilatory pathways. This process is impaired in cerebral amyloid angiopathy, where amyloid-ß(1-40) accumulates around blood vessels. In neurons, amyloid-ß impairs the Ca2+-permeable N-methyl-D-aspartate receptor (NMDAR), a mediator of endothelium-dependent dilation in arteries. We hypothesized that amyloid-ß(1-40) reduces NMDAR-elicited Ca2+ signals in mouse cerebral artery endothelial cells, blunting dilation. Cerebral arteries isolated from 4-5 months-old, male and female cdh5:Gcamp8 mice were used for imaging of unitary Ca2+ influx through NMDAR (NMDAR sparklets) and intracellular Ca2+ transients. The NMDAR agonist NMDA (10 µmol/L) increased frequency of NMDAR sparklets and intracellular Ca2+ transients in endothelial cells; these effects were prevented by NMDAR antagonists D-AP5 and MK-801. Next, we tested if amyloid-ß(1-40) impairs NMDAR-elicited Ca2+ transients. Cerebral arteries incubated with amyloid-ß(1-40) (5 µmol/L) exhibited reduced NMDAR sparklets and intracellular Ca2+ transients. Lastly, we observed that NMDA-induced dilation of pial arteries is reduced by acute intraluminal amyloid-ß(1-40), as well as in a mouse model of Alzheimer's disease, the 5x-FAD, linked to downregulation of Grin1 mRNA compared to wild-type littermates. These data suggest that endothelial NMDAR mediate dilation via Ca2+-dependent pathways, a process disrupted by amyloid-ß(1-40) and impaired in 5x-FAD mice.

Association of persistent tachycardia with early myocardial dysfunction in children undergoing allogeneic hematopoietic cell transplantation.

Cancer survivors who have undergone hematopoietic cell transplantation (HCT) are at risk for myocardial dysfunction. Children who receive allogenic HCT encounter systemic inflammation resulting in tachycardia and hypertension. The effect of these abnormalities on myocardial function is not known. The aim of this study was to determine whether cardiac dysfunction early after HCT can be predicted by tachycardia or hypertension, within a retrospective single-center sample of pediatric HCT recipients. Early tachycardia or hypertension was defined as a majority of values taken from infusion date to 90 days post-infusion being abnormal. Ejection fraction <53% determined systolic dysfunction. A composite score of accepted pediatric diastolic abnormalities determined diastolic dysfunction. Among 80 subjects (median age 8 years), early tachycardia, systolic dysfunction, and diastolic dysfunction were present in 64%, 25%, and 48% of the sample, respectively. In multivariable models, early tachycardia was an independent predictor of early systolic dysfunction (OR = 12.6 [1.4-112.8], p = 0.024) and diastolic dysfunction (OR = 3.9 [1.3-11.5], p = 0.013). Tachycardia and cardiac dysfunction are common and associated with one another in the early period after pediatric HCT. Future studies may elucidate the role of tachycardia and myocardial dysfunction early after HCT as important predictors of future cardiovascular dysfunction.

Patient-Centered Model for Protein-Energy Wasting: Stakeholder Deliberative Panels.

OBJECTIVE: Integrating the patient's voice into research prioritization is essential for solving problems that patients care the most about in terms of health, symptom management, and survival. We used deliberative processes for adapting the existing model of protein-energy wasting (PEW) to one that includes stakeholder priorities, addressing gaps from the initial concept. DESIGN AND METHODS: From September 2015- to December 2017, two diverse, deliberative panels of stakeholders (one for patients and one for clinicians) were recruited from local communities and national networks and met four times to provide an insight into developing a patient-centered model for PEW. After each stakeholder meeting, the research team added the factors and outcomes that reached consensus, using a content analysis. The stakeholder members were then able to confirm what had been collected from an earlier panel discussion and offer additional feedback. The final model was approved by stakeholders. RESULTS: There were eight patient and twelve clinician stakeholders who participated in the panels. Factors and outcomes were only added or modified to the existing model, but none were deleted from the original PEW model. Critical factors identified by the stakeholders were ones related to lifestyle, treatment, and psychosocial aspects. The most important outcomes selected by stakeholders were living longer, staying out of the hospital, and being able to do more. CONCLUSIONS: The approved patient-centered model for PEW represents a testable model for researchers which incorporates the patient's voice. Garnering this insight should assist in the prioritization of projects for a maximal value to patients and their families by future investigators.

Compassion fatigue in nursing: A concept analysis.

AIM: The aim of this article is to clarify the concept of compassion fatigue to develop methods for prevention and mitigation of compassion fatigue in the nursing profession. BACKGROUND: Compassion fatigue occurs when nurses develop declining empathetic ability from repeated exposure to others' suffering. Conceptual clarity is vital to curtail compassion fatigue via preventative and restorative measures at the individual and organizational level. DESIGN: Concept analysis. DATA SOURCES: Databases searched were OVID, CINAHL Complete, Science Direct, Academic One File, Criminal Justice Abstracts, Education Full Text (H.W. Wilson), PsycARTICLES, PsycINFO, Social Work Abstracts, and Teacher Reference Center. Keywords included concept analysis, compassion fatigue, secondary traumatic stress, burnout, vicarious traumatization, compassion satisfaction, nursing, psychology, and social work. The timeline for data collection was from 1990 to 2017. METHODS: Walker and Avant's method of concept analysis. RESULTS: Compassion fatigue occurred across disciplines. Nurses were predisposed to compassion fatigue by repeated exposure of others' suffering, high stress environments, and the continuous giving of self. The consequences of compassion fatigue negatively impacted the nurse, patient, organization, and healthcare system. CONCLUSION: All nurses are at risk for compassion fatigue. Prevention of compassion fatigue is achieved through professional boundaries, self-care measures, self-awareness, and education on the concept at the individual and organizational level.

Is Nutrition Specific Quality of Life Associated With Nutritional Status?

OBJECTIVE: The study purpose was to explore the relationship between nutritional status, as measured by Subjective Global Assessment (SGA), and Health Related Quality of Life measured using the Nutrition Specific Quality of Life (NS-QoL), tool among participants on maintenance hemodialysis (MHD). The study aim was to determine if NS-QoL may be an adjuvant tool for detecting changes in nutritional status among patients on MHD. DESIGN, SETTING, AND SUBJECTS: This is a cross-sectional, secondary analysis of data from a multi-center study. Participants were adult (>18) men and women on MHD (n = 145) recruited from 3 institutions in the Northeastern United States. METHODS: Statistical tests were conducted to determine the relationship between key demographic characteristics (age, sex, dialysis vintage, gender, and ethnicity) and SGA and NS-QoL. Spearman's correlation examined the relationship between the independent variable, SGA and the dependent variable, NS-QoL. A univariate general linear model was conducted to adjust for confounding variables. MAIN OUTCOME MEASURE: The relationship between overall SGA score and composite NS-QoL score. RESULTS: The sample consisted of 85 men (58.6%), with a mean age of 55.3 ± 11.9 years, who were largely African-American (84.1%) and non-Hispanic (77.2%). Mean SGA score was 5.5 ± 1.0, and the mean NS-QoL composite score was 9.51 ± 3.77. No key demographic characteristics had a statistically significant relationship with SGA, whereas sex (P < .001) and race (P = .015) both had statistically significant relationships with NSQoL. After adjusting for the variables of race and sex, NS-QoL score was positively correlated with SGA composite score (P = .042); as NS-QoL score increased so did the SGA score. CONCLUSION: The present study found a positive linear correlation between NS-QoL composite score and SGA, as well as 5 SGA subcomponent scores and NS-QoL. These findings indicate that NS-QoL can complement the SGA to provide information about a patient's nutritional status.

Modeling a Predictive Energy Equation Specific for Maintenance Hemodialysis.

BACKGROUND: Hypermetabolism is theorized in patients diagnosed with chronic kidney disease who are receiving maintenance hemodialysis (MHD). We aimed to distinguish key disease-specific determinants of resting energy expenditure to create a predictive energy equation that more precisely establishes energy needs with the intent of preventing protein-energy wasting. MATERIALS AND METHODS: For this 3-year multisite cross-sectional study (N = 116), eligible participants were diagnosed with chronic kidney disease and were receiving MHD for at least 3 months. Predictors for the model included weight, sex, age, C-reactive protein (CRP), glycosylated hemoglobin, and serum creatinine. The outcome variable was measured resting energy expenditure (mREE). Regression modeling was used to generate predictive formulas and Bland-Altman analyses to evaluate accuracy. RESULTS: The majority were male (60.3%), black (81.0%), and non-Hispanic (76.7%), and 23% were ≥65 years old. After screening for multicollinearity, the best predictive model of mREE (R2 = 0.67) included weight, age, sex, and CRP. Two alternative models with acceptable predictability (R2 = 0.66) were derived with glycosylated hemoglobin or serum creatinine. Based on Bland-Altman analyses, the maintenance hemodialysis equation that included CRP had the best precision, with the highest proportion of participants' predicted energy expenditure classified as accurate (61.2%) and with the lowest number of individuals with underestimation or overestimation. CONCLUSIONS: This study confirms disease-specific factors as key determinants of mREE in patients on MHD and provides a preliminary predictive energy equation. Further prospective research is necessary to test the reliability and validity of this equation across diverse populations of patients who are receiving MHD.

Antagonistic Serotonergic and Octopaminergic Neural Circuits Mediate Food-Dependent Locomotory Behavior in Caenorhabditis elegans.

Biogenic amines are conserved signaling molecules that link food cues to behavior and metabolism in a wide variety of organisms. In the nematode Caenorhabditis elegans, the biogenic amines serotonin (5-HT) and octopamine regulate a number of food-related behaviors. Using a novel method for long-term quantitative behavioral imaging, we show that 5-HT and octopamine jointly influence locomotor activity and quiescence in feeding and fasting hermaphrodites, and we define the neural circuits through which this modulation occurs. We show that 5-HT produced by the ADF neurons acts via the SER-5 receptor in muscles and neurons to suppress quiescent behavior and promote roaming in fasting worms, whereas 5-HT produced by the NSM neurons acts on the MOD-1 receptor in AIY neurons to promote low-amplitude locomotor behavior characteristic of well fed animals. Octopamine, produced by the RIC neurons, acts via SER-3 and SER-6 receptors in SIA neurons to promote roaming behaviors characteristic of fasting animals. We find that 5-HT signaling is required for animals to assume food-appropriate behavior, whereas octopamine signaling is required for animals to assume fasting-appropriate behavior. The requirement for both neurotransmitters in both the feeding and fasting states enables increased behavioral adaptability. Our results define the molecular and neural pathways through which parallel biogenic amine signaling tunes behavior appropriately to nutrient conditions.SIGNIFICANCE STATEMENT Animals adjust behavior in response to environmental changes, such as fluctuations in food abundance, to maximize survival and reproduction. Biogenic amines, such as like serotonin, are conserved neurotransmitters that regulate behavior and metabolism in relation to energy status. Disruptions of biogenic amine signaling contribute to human neurological diseases of mood, appetite, and movement. In this study, we investigated the roles of the biogenic amines serotonin and octopamine in regulating locomotion behaviors associated with feeding and fasting in the roundworm Caenorhabditis elegans We identified neural circuits through which these signals work to govern behavior. Understanding the molecular pathways through which biogenic amines function in model organisms may improve our understanding of dysfunctions of appetite and behavior found in mammals, including humans.

Comparison of Subjective Global Assessment and Protein Energy Wasting Score to Nutrition Evaluations Conducted by Registered Dietitian Nutritionists in Identifying Protein Energy Wasting Risk in Maintenance Hemodialysis Patients.

OBJECTIVE: To compare the 7-point subjective global assessment (SGA) and the protein energy wasting (PEW) score with nutrition evaluations conducted by registered dietitian nutritionists in identifying PEW risk in stage 5 chronic kidney disease patients on maintenance hemodialysis. DESIGN AND METHODS: This study is a secondary analysis of a cross-sectional study entitled "Development and Validation of a Predictive energy Equation in Hemodialysis". PEW risk identified by the 7-point SGA and the PEW score was compared against the nutrition evaluations conducted by registered dietitian nutritionists through data examination from the original study (reference standard). SUBJECTS: A total of 133 patients were included for the analysis. MAIN OUTCOME MEASURES: The sensitivity, specificity, positive and negative predictive value (PPV and NPV), positive and negative likelihood ratio (PLR and NLR) of both scoring tools were calculated when compared against the reference standard. RESULTS: The patients were predominately African American (n = 112, 84.2%), non-Hispanic (n = 101, 75.9%), and male (n = 80, 60.2%). Both the 7-point SGA (sensitivity = 78.6%, specificity = 59.1%, PPV = 33.9%, NPV = 91.2%, PLR = 1.9, and NLR = 0.4) and the PEW score (sensitivity = 100%, specificity = 28.6%, PPV = 27.2%, NPV = 100%, PLR = 1.4, and NLR = 0) were more sensitive than specific in identifying PEW risk. The 7-point SGA may miss 21.4% patients having PEW and falsely identify 40.9% of patients who do not have PEW. The PEW score can identify PEW risk in all patients, but 71.4% of patients identified may not have PEW risk. CONCLUSIONS: Both the 7-point SGA and the PEW score could identify PEW risk. The 7-point SGA was more specific, and the PEW score was more sensitive. Both scoring tools were found to be clinically confident in identifying patients who were actually not at PEW risk.

Effects of sulfate and sulfide on the life cycle of Zizania palustris in hydroponic and mesocosm experiments.

Under oxygenated conditions, sulfate is relatively non-toxic to aquatic plants. However, in water-saturated soils, which are usually anoxic, sulfate can be reduced to toxic sulfide. Although the direct effects of sulfate and sulfide on the physiology of a few plant species have been studied in some detail, their cumulative effects on a plant's life cycle through inhibition of seed germination, seedling survival, growth, and seed production have been less well studied. We investigated the effect of sulfate and sulfide on the life cycle of wild rice (Zizania palustris L.) in hydroponic solutions and in outdoor mesocosms with sediment from a wild rice lake. In hydroponic solutions, sulfate had no effect on seed germination or juvenile seedling growth and development, but sulfide greatly reduced juvenile seedling growth and development at concentrations greater than 320 µg/L. In outdoor mesocosms, sulfate additions to overlying water increased sulfide production in sediments. Wild rice seedling emergence, seedling survival, biomass growth, viable seed production, and seed mass all declined with sulfate additions and hence sulfide concentrations in sediment. These declines grew steeper during the course of the 5 yr of the mesocosm experiment and wild rice populations became extinct in most tanks with concentrations of 250 mg SO4 /L or greater in the overlying water. Iron sulfide precipitated on the roots of wild rice plants, especially at high sulfate application rates. These precipitates, or the encroachment of reducing conditions that they indicate, may impede nutrient uptake and be partly responsible for the reduced seed production and viability.

Abbreviated Steady State Intervals for Measuring Resting Energy Expenditure in Patients on Maintenance Hemodialysis.

BACKGROUND: Indirect calorimetry requires a steady state (SS) protocol to determine measured resting energy expenditure (mREE). Achieving stringent criteria for an SS interval may be difficult for patients on maintenance hemodialysis (MHD), as they may become uncomfortable because of the test itself or their health status. The study aim was to explore if a shortened SS interval was within acceptable limits for bias and precision. MATERIALS AND METHODS: For this cross-sectional secondary analysis, adults (N = 125) who received MHD thrice weekly were enrolled. The indirect calorimetry test was performed for a length of total time ≤30 consecutive minutes. SS was evaluated in accordance with intervals of 10, 5, 4, 3, and 2 minutes. The mREE at the 10-minute SS was compared with the mREE at 5, 4, 3, and 2 minutes, via t tests and Bland-Altman analysis, to determine degree of bias and level of agreement. The a priori alpha level was set at ≤0.5. RESULTS: The sample was primarily male, African American, and non-Hispanic, with a mean ± SD age of 55.4 ± 12.2 years, who reported being on MHD for an average of 62.4 ± 74.3 months. None of the mREE measures were significantly different from that of the 10-minute SS interval. Seventy-two percent of the participants were able to achieve SS at the 10-minute interval, 83.2% at 5 minutes, 87.2% at 4 minutes, and 89.6% for both 3 and 2 minutes. CONCLUSION: For patients on MHD, an abbreviated SS interval of <10 minutes (eg, 5 minutes) yielded valid mREE measurements.

Bioanalytical applications of surface-enhanced Raman spectroscopy: de novo molecular identification.

Surface enhanced Raman scattering (SERS) has become a powerful technique for trace analysis of biomolecules. The use of SERS-tags has evolved into clinical diagnostics, the enhancement of the intrinsic signal of biomolecules on SERS active materials shows tremendous promise for the analysis of biomolecules and potential biomedical assays. The detection of the de novo signal from a wide range of biomolecules has been reported to date. In this review, we examine different classes of biomolecules for the signals observed and experimental details that enable their detection. In particular, we survey nucleic acids, amino acids, peptides, proteins, metabolites, and pathogens. The signals observed show that the interaction of the biomolecule with the enhancing nanostructure has a significant influence on the observed spectrum. Additional experiments demonstrate that internal standards can correct for intensity fluctuations and provide quantitative analysis. Experimental methods that control the interaction at the surface are providing for reproducible SERS signals. Results suggest that combining advances in methodology with the development of libraries for SERS spectra may enable the characterization of biomolecules complementary to other existing methods.

Molecular precursors to gallium oxide thin films.

The donor-functionalised alkoxides [Et(2)Ga(OR)](2)(R = CH(2)CH(2)NMe(2)(1), CH(CH(2)NMe(2))(2)(2), CH(2)CH(2)OMe (3), CH(CH(3))CH(2)NMe(2)(4), C(CH(3))(2)CH(2)OMe (5)) were synthesised by the 1:1 reaction of Et(3)Ga with ROH in hexane or dichloromethane at room temperature. Reaction of Et(3)Ga with excess ROH in refluxing toluene resulted in the isolation of a 1:1 mixture of [Et(2)Ga(OR)](2) and the ethylgallium bisalkoxide [EtGa(OR)(2)](R = CH(2)CH(2)NMe(2)(6) or CH(CH(3))CH(2)NMe(2)(7)). X-ray crystallography showed that compound 6 is monomeric and this complex represents the first structurally characterised monomeric gallium bisalkoxide. Homoleptic gallium trisalkoxides [Ga(OR)(3)](2) were prepared by the 1:6 reaction of [Ga(NMe(2))(3)](2) with ROH (R = CH(2)CH(2)NMe(2)(8), CH(CH(3))CH(2)NMe(2)(9), C(CH(3))(2)CH(2)OMe (10)). The decomposition of compounds 1, 4, 5 and 8 were studied by thermal gravimetric analysis. Low pressure CVD of 1 and 5 resulted in the formation of thin films of crystalline Ga(2)O(3).