Pressure ulcers and nutritional deficits in elderly long-term care patients: Effects of a comprehensive nutritional program on pressure ulcer healing, length of hospital stay and charges to patients

The elderly are at the highest risk of developing pressure ulcers that result in prolonged hospitalization, high health care costs, increased mortality, and decreased quality of life. The burden of pressure ulcers will intensify because of a rapidly increasing elderly population in the United States (US). Poor nutrition is a major predictor of pressure ulcer formation. The purpose of this study was to examine the effects of a comprehensive, interdisciplinary nutritional protocol on: (1) pressure ulcer wound healing (2) length of hospital stays, and (3) charges for pressure ulcer management. Using a pre-intervention/post intervention quasi-experimental design the study sample was composed of 100 patients 60 years or older, admitted with or acquiring a pressure ulcer. A pre-intervention group (n= 50) received routine pressure ulcer care (standard diet, dressing changes, and equipment). A post-intervention group received routine care plus an interdisciplinary nutrition intervention (physical therapy, speech therapy, occupational therapy, added protein and calories to the diet). Research questions were analyzed using descriptive statistics, frequencies, Chi-Square Tests, and T-tests. Findings indicated that the comprehensive, interdisciplinary nutritional protocol had a significant effect on the rate of wound healing in Week3 and Week4, total hospital length of stay (pre-intervention M= 43.2 days, SD=31.70 versus M=31.77, SID-12.02 post-intervention), and pressure ulcer length of stay (pre-intervention 25.28 days, SD5.60 versus 18.40 days, SD 5.27 post-intervention). Although there was no significant difference in total charges for the pre-intervention group ($727,245.00) compared to the post-intervention group ($702,065.00), charges for speech (m=$5885.12, SD=$332.55), pre albumin (m=$808.52,SD= $332.55), and albumin($278 .88, SD=55.00) were higher in the pre-intervention group and charges for PT ($5721.26, SD$3655.24) and OT($2544 .64, SD=1712.863) were higher in the post-intervention group. Study findings indicate that this comprehensive nutritional intervention was effective in improving pressure ulcer wound healing, decreasing both hospital length of stay for treatment of pressure ulcer and total hospital length of stay while showing no significant additional charges for treatment of pressure ulcers.

Mechanical and electrical properties of single-walled carbon nanotubes synthesized by chemical vapor deposition

Despite the tremendous application potentials of carbon nanotubes (CNTs) proposed by researchers in the last two decades, efficient experimental techniques and methods are still in need for controllable production of CNTs in large scale, and for conclusive characterizations of their properties in order to apply CNTs in high accuracy engineering. In this dissertation, horizontally well-aligned high quality single-walled carbon nanotubes (SWCNTs) have been successfully synthesized on St-cut quartz substrate by chemical vapor deposition (CVD). Effective radial moduli (Eradial) of these straight SWCNTs have been measured by using well-calibrated tapping mode and contact mode atomic force microscopy (AFM). It was found that the measured Eradial decreased from 57 to 9 GPa as the diameter of the SWCNTs increased from 0.92 to 1.91 nm. The experimental results were consistent with the recently reported theoretical simulation data. The method used in this mechanical property test can be easily applied to measure the mechanical properties of other low-dimension nanostructures, such as nanowires and nanodots. The characterized sample is also an ideal platform for electrochemical tests. The electrochemical activities of redox probes Fe(CN)63-/4-, Ru(NH3) 63+, Ru(bpy)32+ and protein cytochrome c have been studied on these pristine thin films by using aligned SWCNTs as working electrodes. A simple and high performance electrochemical sensor was fabricated. Flow sensing capability of the device has been tested for detecting neurotransmitter dopamine at physiological conditions with the presence of Bovine serum albumin. Good sensitivity, fast response, high stability and anti-fouling capability were observed. Therefore, the fabricated sensor showed great potential for sensing applications in complicated solution.^

Covalent protein adduction of nitrogen mustards and related compounds

Chemical warfare agents continue to pose a global threat despite the efforts of the international community to prohibit their use in warfare. For this reason, improvement in the detection of these compounds remains of forensic interest. Protein adducts formed by the covalent modification of an electrophilic xenobiotic and a nucleophilic amino acid may provide a biomarker of exposure that is stable and specific to compounds of interest (such as chemical warfare agents), and have the capability to extend the window of detection further than the parent compound or circulating metabolites. This research investigated the formation of protein adducts of the nitrogen mustard chemical warfare agents mechlorethamine (HN-2) and tris(2-chloroethyl)amine (HN-3) to lysine and histidine residues found on the blood proteins hemoglobin and human serum albumin. Identified adducts were assessed for reproducibility and stability both in model peptide and whole protein assays. Specificity of these identified adducts was assessed using in vitro assays to metabolize common therapeutic drugs containing nitrogen mustard moieties. Results of the model peptide assays demonstrated that HN-2 and HN-3 were able to form stable adducts with lysine and histidine residues under physiological conditions. Results for whole protein assays identified three histidine adducts on hemoglobin, and three adducts (two lysine residues and one histidine residue) on human serum albumin that were previously unknown. These protein adducts were determined to be reproducible and stable at physiological conditions over a three-week analysis period. Results from the in vitro metabolic assays revealed that adducts formed by HN-2 and HN-3 are specific to these agents, as metabolized therapeutic drugs (chlorambucil, cyclophosphamide, and melphalan) did not form the same adducts on lysine or histidine residues as the previously identified adducts formed by HN-2 and HN-3. Results obtained from the model peptide and full protein work were enhanced by comparing experimental data to theoretical calculations for adduct formation, providing further confirmatory data. This project was successful in identifying and characterizing biomarkers of exposure to HN-2 and HN-3 that are specific and stable and which have the potential to be used for the forensic determination of exposure to these dangerous agents.

Pressure ulcers and nutritional deficits in elderly long-term care patients : effects of a comprehensive nutritional program on pressure ulcer healing, length of hospital stay and charges to patients

The elderly are at the highest risk of developing pressure ulcers that result in prolonged hospitalization, high health care costs, increased mortality, and decreased quality of life. The burden of pressure ulcers will intensify because of a rapidly increasing elderly population in the United States (US). Poor nutrition is a major predictor of pressure ulcer formation. The purpose of this study was to examine the effects of a comprehensive, interdisciplinary nutritional protocol on: 1) pressure ulcer wound healing 2) length of hospital stays, and 3) charges for pressure ulcer management. Using a pre-intervention/post intervention quasi-experimental design the study sample was composed of 100 patients 60 years or older, admitted with or acquiring a pressure ulcer. A pre-intervention group (n= 50) received routine pressure ulcer care (standard diet, dressing changes, and equipment). A post-intervention group received routine care plus an interdisciplinary nutrition intervention (physical therapy, speech therapy, occupational therapy, added protein and calories to the diet). Research questions were analyzed using descriptive statistics, frequencies, Chi-Square Tests, and T-tests. Findings indicated that the comprehensive, interdisciplinary nutritional protocol had a significant effect on the rate of wound healing in Week3 and Week4, total hospital length of stay (pre-intervention M= 43.2 days, SD=31.70 versus M=31.77, SD=12.02 post-intervention), and pressure ulcer length of stay (pre-intervention 25.28 days, SD5.60 versus 18.40 days, SD 5.27 post-intervention). Although there was no significant difference in total charges for the pre-intervention group ($727,245.00) compared to the post-intervention group ($702,065.00), charges for speech (m=$5885.12, SD=$332.55), pre albumin (m=$808.52,SD= $332.55), and albumin($278 .88, SD=55.00) were higher in the pre-intervention group and charges for PT ($5721.26, SD$3655.24) and OT($2544 .64, SD=1712.863) were higher in the post-intervention group. Study findings indicate that this comprehensive nutritional intervention was effective in improving pressure ulcer wound healing, decreasing both hospital length of stay for treatment of pressure ulcer and total hospital length of stay while showing no significant additional charges for treatment of pressure ulcers.

Mechanical and Electrical Properties of Single-walled Carbon Nanotubes Synthesized by Chemical Vapor Deposition

Despite the tremendous application potentials of carbon nanotubes (CNTs) proposed by researchers in the last two decades, efficient experimental techniques and methods are still in need for controllable production of CNTs in large scale, and for conclusive characterizations of their properties in order to apply CNTs in high accuracy engineering. In this dissertation, horizontally well-aligned high quality single-walled carbon nanotubes (SWCNTs) have been successfully synthesized on St-cut quartz substrate by chemical vapor deposition (CVD). Effective radial moduli (Eradial) of these straight SWCNTs have been measured by using well-calibrated tapping mode and contact mode atomic force microscopy (AFM). It was found that the measured Eradial decreased from 57 to 9 GPa as the diameter of the SWCNTs increased from 0.92 to 1.91 nm. The experimental results were consistent with the recently reported theoretical simulation data. The method used in this mechanical property test can be easily applied to measure the mechanical properties of other low-dimension nanostructures, such as nanowires and nanodots. The characterized sample is also an ideal platform for electrochemical tests. The electrochemical activities of redox probes Fe(CN)63-/4-, Ru(NH3)63+, Ru(bpy)32+ and protein cytochrome c have been studied on these pristine thin films by using aligned SWCNTs as working electrodes. A simple and high performance electrochemical sensor was fabricated. Flow sensing capability of the device has been tested for detecting neurotransmitter dopamine at physiological conditions with the presence of Bovine serum albumin. Good sensitivity, fast response, high stability and anti-fouling capability were observed. Therefore, the fabricated sensor showed great potential for sensing applications in complicated solution.