187 research outputs found
Ten year review of melanoma with regression
Melanoma with regression is seen in 10-35% of cutaneous melanomas. We retrospectively reviewed our experience with these unusual melanomas
Balancing the Intermolecular Forces in Peptide Amphiphiles for pH-Triggered Self-Assembly
The design of novel self-assembling biomaterials that change morphology in response to
specific stimuli can lead to much advancement in designing next generation sensors, diagnostic
and therapeutic agents. We have previously developed a new class of self-assembling materials
known as peptide amphiphiles (PA) that transform from spherical micelles to nanofibers in the
slightly acidic environment of cancerous tissue, as a novel mechanism to enhance their
accumulation at the tumor site relative to normal tissue. A typical PA that we construct consists
of an alkyl tail, followed by an amino acid sequence, and terminated with a MRI imaging agent.
However, designing this vehicle that will transform under a specific pH value in vivo requires a
more detailed understanding of the relative attractive hydrophobic and the repulsive electrostatic
forces in these surfactant-like molecules. Here, we specifically studied how the alkyl chain
length, the number of anionic amino acids in the moleculeâs charged region, and the number of
tyrosine (Y) residues in the its beta sheet region affect the sphere to nanofiber transition pH,
starting from palmitoyl-YYAAEEEEK(DO3A:Gd)-NH2. In general, it was shown that increasing
the alkyl chain length promotes nanofiber formation under a given set of conditions, while
increasing the number of charged amino acids promotes micelle formation. Furthermore, it was
determined that the addition of a fifth glutamic acid shifts the pH of the sphere to nanofiber
transition to a slightly more acidic value as compared to the deletion of a single methylene group
or tyrosine residue.2013 Mayers Summer Research FellowshipNo embargoAcademic Major: Chemistr
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Final Report - Advanced Conceptual Models for Unsaturated and Two-Phase Flow in Fractured Rock
The Department of Energy Environmental Management Program is faced with two major issues involving two-phase flow in fractured rock; specifically, transport of dissolved contaminants in the Vadose Zone, and the fate of Dense Nonaqueous Phase Liquids (DNAPLs) below the water table. Conceptual models currently used to address these problems do not correctly include the influence of the fractures, thus leading to erroneous predictions. Recent work has shown that it is crucial to understand the topology, or ''structure'' of the fluid phases (air/water or water/DNAPL) within the subsurface. It has also been shown that even under steady boundary conditions, the influence of fractures can lead to complex and dynamic phase structure that controls system behavior, with or without the presence of a porous rock matrix. Complicated phase structures within the fracture network can facilitate rapid transport, and lead to a sparsely populated and widespread distribution of concentrated contaminants; these qualities are highly difficult to describe with current conceptual models. The focus of our work is to improve predictive modeling through the development of advanced conceptual models for two-phase flow in fractured rock
Computer assisted analysis of discontinuous rock masses
Online access for this thesis was created in part with support from the Institute of Museum and Library Services (IMLS) administered by the Nevada State Library, Archives and Public Records through the Library Services and Technology Act (LSTA). To obtain a high quality image or document please contact the DeLaMare Library at https://unr.libanswers.com/ or call: 775-784-6945.A computerized data handling system has been developed to assist in analysis of discontinuous rock masses
Outcomes of breech birth by mode of delivery: a population linkage study
Background: Trial evidence supports a policy of caesarean section for singleton breech presentations at term but vaginal breech birth is considered a safe option for selected women. Aims: To provide recent Australian data on outcomes associated with intended mode of delivery for term breech singletons in women who meet conservative eligibility criteria for vaginal breech birth. Materials and Methods: Birth and hospital records from 2009 to 2012 in New South Wales were used to identify women with non-anomalous pregnancies who would be considered eligible for vaginal breech birth. Intended mode of delivery was inferred from labour onset and management. Results: Of 10,133 women with term breech singleton pregnancies, 5,197 (51.3%) were classified as eligible for vaginal breech delivery. Of these, 6.8% intended vaginal breech birth, 76.4% planned caesarean section, and intention could not be determined for 16.8%. Women intending vaginal delivery had higher rates of neonatal morbidity (6.0% vs. 2.1%), neonatal birth trauma (7.4% vs. 0.9%), Apgar <4 at 1 minute (10.5% vs. 1.1%), Apgar<7 at 5 minutes (4.3% vs. 0.5%), and NICU/SCN admissions (16.2% vs. 6.6%) than those planning caesarean section. Increased perinatal risks remained after adjustment for maternal characteristics. Severe maternal morbidity (1.4% vs. 0.7%) and postpartum readmission (4.6% vs. 4.0%) were higher in the intended vaginal compared to planned caesarean births but these differences were not statistically significant. Conclusions: In a population of women classified as being eligible for vaginal breech birth, intended vaginal delivery was associated with higher rates of neonatal morbidity than planned caesarean section.NHMRC, AR
Oxidative stress, protein glycation and nutrition â interactions relevant to health and disease throughout the lifecycle
Protein glycation has been studied for over a century now and plays an important role in disease pathogenesis throughout the lifecycle. Strongly related to diabetic complications, glycation of Hb has become the gold standard method for diabetes diagnosis and monitoring. It is however attracting attention in normoglycaemia as well lately. Longitudinal studies increasingly suggest a positive relationship between glycation and the risk of chronic diseases in normoglycaemic individuals, but the mechanisms behind this association remain unclear. The interaction between glycation and oxidative stress may be particularly relevant in the normoglycaemic context, as suggested by recent epidemiological and in vitro evidence. In that context nutritional and lifestyle factors with an influence on redox status, such as smoking, fruit and vegetable and antioxidants consumption, may have the capacity to promote or inhibit glycation. However, experimental data from controlled trials are lacking the quality and rigour needed to reach firm conclusions. In the present review, we discuss the importance of glycation for health through the lifecycle and focus on the importance of oxidative stress as a driver for glycation. The importance of nutrition to modulate glycation is discussed, based on the evidence available and recommendations towards higher quality future research are made
Mildly Hydrophobic Biobased Mulch: A Sustainable Approach to Controlling Bare Soil Evaporation
© 2020 The Authors. Vadose Zone Journal published by Wiley Periodicals LLC on behalf of Soil Science Society of America Mulching with polyethylene film is the conventional approach to decrease evaporative water loss from agricultural soils, but it is not environmentally sustainable. In this study, a laboratory experiment was conducted to test the potential utility of partially polymerized soybean oil (PSO) coated sands as a surface treatment to reduce bare soil evaporation. Evaporation was tracked for 23.8 d from saturated sand columns treated with a surface layer (1 or 2 cm) of either coated medium sand (MS-PSO) or coated coarse sand (CS-PSO). The water drop penetration time (WDPT) was used to assess the hydrophobicity of fresh PSO-coated sands; the saturated hydraulic conductivity (Ks) and particle density (Ïs) were measured as well. The WDPT was also tested on MS-PSO and CS-PSO samples aged in four separate environmental conditions for 20â21 d. Both PSO-coated sands were mildly hydrophobic, and the surface treatment layers reduced evaporative loss by 83â96% over bare soil, which is similar to previous work using extremely hydrophobic chemically treated sands. Freshly coated MS-PSO had a higher WDPT score and lower Ks than CS-PSO. After the environmental aging tests, the MS-PSO and CS-PSO samples remained mildly hydrophobic. Notably, CS-PSO had a low initial WDPT (âŒ1.09 to âŒ2.58 s) and a high Ks (2.66 Ă 10â1 cm sâ1), suggesting coarse PSO-coated sands will permit infiltration. Given these findings, PSO-coated sand has the potential to be developed into a sustainable alternative to polyethylene film mulch
Contribution of Changing Risk Factors to the Trend in Breech Presentation at Term
Background: Recent population-wide changes in perinatal risk factors may affect rates of breech presentation at birth, and have implications for the provision of breech services and clinical training in breech management. Aims: To determine the trend in breech presentation at term and investigate whether changes in maternal and pregnancy characteristics explain the observed trend. Materials and Methods: All singleton term (â„37 week) births in New South Wales during 2002 â 2012 were identified through birth and associated hospital records. Annual rates of breech presentation were determined. Logistic regression modelling was used to predict expected rates of breech presentation over time and these were compared with observed rates. A priori predictors included maternal age, country of birth, parity, smoking during pregnancy, diabetes, pregnancy hypertension, placenta praevia, previous singleton term breech, previous caesarean section, infant sex, gestational age, birthweight, and congenital anomalies. Hospital and Medicare data were used to assess trends in external cephalic version. Results: Among 914,147 singleton term births, 3.1% were breech at delivery. Rates declined from 3.6% in 2002 to 2.7% in 2012 (test for trend p<0.001). Breech presentation was predicted to increase from 3.6% in 2002 to 4.3% in 2012 because of increased maternal age, nulliparity, maternal diabetes, history of breech presentation and previous caesarean section. Use of external cephalic version appears to have increased over time. Conclusions: Breech presentation at delivery has decreased in New South Wales. Increased use of external cephalic version likely accounts for this decline, as changes in risk factors do not.NHMRC, AR
Woman-centred maternity care: what do women say? Protocol for a survey of women receiving maternity care in NSW
Background: Over the past decade or so, recommendations for improvements in maternity care have emphasised the importance of providing woman-centred care. Feedback from women about existing maternity services can help to identify whether services are currently meeting womenâs needs. The present study aims to capture womenâs expectations of, and experiences with maternity care, and to explore whether maternal and birth characteristics are associated with those experiences. Methods: A survey will be undertaken with a sample of approximately 2,000 women who have given birth over a 3-month period at seven public maternity units in two neighbouring health districts in New South Wales (NSW), Australia. The survey will be mailed out three-four months after birth. The study will also examine two strategies intended to increase survey response rates: use of two types of pre-notification letters, and request for consent from women to link survey responses with health information recorded at the time of birth. Data analysis will examine response rate, evidence of sample bias and effect of pre-notification letters; describe expectations and experiences with maternity care and associations with maternal and/or health characteristics; and where possible, compare results with maternity satisfaction data reported by others. Discussion: This study will provide, for the first time in NSW, comprehensive information about womenâs expectations, experiences and satisfaction with maternity services in two local health districts. It will identify aspects of care that are meeting womenâs needs, and areas where care and service provision may be improved in line with the aspirations of Towards Normal Birth. The survey tool may also prove to be appropriate for use by other health districts and/or state-wide.NHMR
Woman-centred maternity care: what do women say? Protocol for a survey of women receiving maternity care in NSW
Background: Over the past decade or so, recommendations for improvements in maternity care have emphasised the importance of providing woman-centred care. Feedback from women about existing maternity services can help to identify whether services are currently meeting womenâs needs. The present study aims to capture womenâs expectations of, and experiences with maternity care, and to explore whether maternal and birth characteristics are associated with those experiences. Methods: A survey will be undertaken with a sample of approximately 2,000 women who have given birth over a 3-month period at seven public maternity units in two neighbouring health districts in New South Wales (NSW), Australia. The survey will be mailed out three-four months after birth. The study will also examine two strategies intended to increase survey response rates: use of two types of pre-notification letters, and request for consent from women to link survey responses with health information recorded at the time of birth. Data analysis will examine response rate, evidence of sample bias and effect of pre-notification letters; describe expectations and experiences with maternity care and associations with maternal and/or health characteristics; and where possible, compare results with maternity satisfaction data reported by others. Discussion: This study will provide, for the first time in NSW, comprehensive information about womenâs expectations, experiences and satisfaction with maternity services in two local health districts. It will identify aspects of care that are meeting womenâs needs, and areas where care and service provision may be improved in line with the aspirations of Towards Normal Birth. The survey tool may also prove to be appropriate for use by other health districts and/or state-wide.NHMR
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