bluuebunny/crossref_metadata_2025 huggingface dataset:
In Situ Bioreactors and Deep Drain‐Pipe Installation to Reduce Nitrate Losses in Artificially Drained Fields
Authors: Jaynes Dan B. , Kaspar Tom C. , Moorman Tom B. , Parkin Tim B.
Published: February 2008

Nitrate in water removed from fields by subsurface drain (‘tile’) systems is often at concentrations exceeding the 10 mg N L−1 maximum contaminant level (MCL) set by the USEPA for drinking water and has been implicated in contributing to the hypoxia problem within the northern Gulf of Mexico. Because previous research shows that N fertilizer management alone is not sufficient for reducing NO3 concentrations in subsurface drainage below the MCL, additional approaches are needed. In this field study, we compared the NO3 losses in tile drainage from a conventional drainage system (CN) consisting of a free‐flowing pipe installed 1.2 m below the soil surface to losses in tile drainage from two alternative drainage designs. The alternative treatments were a deep tile (DT), where the tile drain was installed 0.6 m deeper than the conventional tile depth, but with the outlet maintained at 1.2 m, and a denitrification wall (DW), where trenches excavated parallel to the tile and filled with woodchips serve as additional carbon sources to increase denitrification. Four replicate 30.5‐ by 42.7‐m field plots were installed for each treatment in 1999 and a corn–soybean rotation initiated in 2000. Over 5 yr (2001–2005) the tile flow from the DW treatment had annual average NO3 concentrations significantly lower than the CN treatment (8.8 vs. 22.1 mg N L−1). This represented an annual reduction in NO3 mass loss of 29 kg N ha−1 or a 55% reduction in nitrate mass lost in tile drainage for the DW treatment. The DT treatment did not consistently lower NO3 concentrations, nor reduce the annual NO3 mass loss in drainage. The DT treatment did exhibit lower NO3 concentrations in tile drainage than the CN treatment during late summer when tile flow rates were minimal. There was no difference in crop yields for any of the treatments. Thus, denitrification walls are able to substantially reduce NO3 concentrations in tile drainage for at least 5 yr.
Assessment of Chlorophyll‐a as a Criterion for Establishing Nutrient Standards in the Streams and Rivers of Illinois
Authors: Royer Todd V. , David Mark B. , Gentry Lowell E. , Mitchell Corey A. , Starks Karen M. , Heatherly Thomas , Whiles Matt R.
Published: February 2008

Nutrient enrichment is a frequently cited cause for biotic impairment of streams and rivers in the USA. Efforts are underway to develop nutrient standards in many states, but defensible nutrient standards require an empirical relationship between nitrogen (N) or phosphorus (P) concentrations and some criterion that relates nutrient levels to the attainment of designated uses. Algal biomass, measured as chlorophyll‐a (chl‐a), is a commonly proposed criterion, yet nutrient–chl‐a relationships have not been well documented in Illinois at a state‐wide scale. We used state‐wide surveys of >100 stream and river sites to assess the applicability of chl‐a as a criterion for establishing nutrient standards for Illinois. Among all sites, the median total P and total N concentrations were 0.185 and 5.6 mg L−1, respectively, during high‐discharge conditions. During low‐discharge conditions, median total P concentration was 0.168 mg L−1, with 25% of sites having a total P of ≥0.326 mg L−1 Across the state, 90% of the sites had sestonic chl‐a values of ≤35 μg L−1, and watershed area was the best predictor of sestonic chl‐a During low discharge there was a significant correlation between sestonic chl‐a and total P for those sites that had canopy cover ≤25% and total P of ≤0.2 mg L−1 Results suggest sestonic chl‐a may be an appropriate criterion for the larger rivers in Illinois but is inappropriate for small rivers and streams. Coarse substrate to support benthic chl‐a occurred in <50% of the sites we examined; a study using artificial substrates did not reveal a relationship between chl‐a accrual and N or P concentrations. For many streams and rivers in Illinois, nutrients may not be the limiting factor for algal biomass due to the generally high nutrient concentrations and the effects of other factors, such as substrate conditions and turbidity.
Phosphorus Loss from an Agricultural Watershed as a Function of Storm Size
Authors: Sharpley Andrew N. , Kleinman Peter J. A. , Heathwaite A. Louise , Gburek William J. , Folmar Gordon J. , Schmidt John P.
Published: February 2008

Phosphorus (P) loss from agricultural watersheds is generally greater in storm rather than base flow. Although fundamental to P‐based risk assessment tools, few studies have quantified the effect of storm size on P loss. Thus, the loss of P as a function of flow type (base and storm flow) and size was quantified for a mixed‐land use watershed (FD‐36; 39.5 ha) from 1997 to 2006. Storm size was ranked by return period (<1, 1–3, 3–5, 5–10, and >10 yr), where increasing return period represents storms with greater peak and total flow. From 1997 to 2006, storm flow accounted for 32% of watershed discharge yet contributed 65% of dissolved reactive P (DP) (107 g ha−1 yr−1) and 80% of total P (TP) exported (515 g ha−1 yr−1). Of 248 storm flows during this period, 93% had a return period of <1 yr, contributing most of the 10‐yr flow (6507 m3 ha−1; 63%) and export of DP (574 g ha−1; 54%) and TP (2423 g ha−1; 47%). Two 10‐yr storms contributed 23% of P exported between 1997 and 2006. A significant increase in storm flow DP concentration with storm size (0.09–0.16 mg L−1) suggests that P release from soil and/or area of the watershed producing runoff increase with storm size. Thus, implementation of P‐based Best Management Practice needs to consider what level of risk management is acceptable.
The New Gold Rush: Fueling Ethanol Production while Protecting Water Quality
Authors: Simpson Thomas W. , Sharpley Andrew N. , Howarth Robert W. , Paerl Hans W. , Mankin Kyle R.
Published: February 2008

Renewable fuel production, particularly grain‐based ethanol, is expanding rapidly in the USA. Although subsidized grain‐based ethanol may provide a competitively priced transportation fuel, concerns exist about potential environmental impacts. This contribution focuses on potential water quality implications of expanded grain‐based ethanol production and potential impacts of perennial‐grass–based cellulosic ethanol. Expanded grain‐based ethanol will increase and intensify corn production. Even with recommended fertilizer and land conservation measures, corn acreage can be a major source of N loss to water (20–40 kg ha−1 yr−1). A greater acreage of corn is estimated to increase N and P loss to water by 37% (117 million kg) and 25% (9 million kg), respectively, and measures to encourage adoption of conservation practices are essential to mitigate water quality impairments. Dried distiller's grains remaining after ethanol production from corn grain are used as animal feed and can increase manure P content and may increase N content. Cellulosic fuel‐stocks from perennials such as switchgrass and woody materials have the potential to produce ethanol. Although production, storage, and handling of cellulosic materials and conversion technology are limitations, accelerating development of cellulosic ethanol has the potential to reduce dependence on grain fuel‐stocks and provide water quality and other environmental benefits. All alternative fuel production technologies could have environmental impacts. There is a need to understand these impacts to help guide policy and help make programmatic and scientific decisions that avoid or mitigate unintended environmental consequences of biofuel production.
A Membrane-Based Flow-through Hybridization Technology: A Rapid
and Versatile tool for Molecular Diagnostics
Authors: Chow K.F.J.
Published: February 2008

Genetic diseases remain an important cause of ailment, morbidity and death for children and adults. Despite the
recent advances of tools for molecular diagnosis such as DNA chips and protein arrays which are capable of analyzing
many genes, SNPs and proteins, few of these systems have been applied in clinical diagnosis because the apparatus are
still expensive and many of the genetic tests are less likely to be developed commercially. Hence most genetic tests are
still being performed through conventional methods such as Dot-Blot hybridization and Slot-blot hybridization in clinical
laboratories worldwide. The expensive, time consuming and labor-intensive nature of these tests make them unaffordable
for popular use. The availability of a low-cost diagnostic system will make molecular testing cost efficient and become
readily available worldwide. In this report, we evaluated the Flow-through hybridization system. Our results show that
Flow-through hybridization method produces higher sensitivity in 5 to 15 minutes compared to those obtained through
conventional hybridization in hours to overnight respectively without sacrificing specificity. An apparatus can also be
readily adopted for membrane-based home-brew tests, R&D development as well as other commercially available diagnostic
kits, hence making the Flow-through method a useful tool for molecular diagnosis.
Relationship of Apolipoprotein B Levels to the Number of Risk Factors for Metabolic Syndrome
Authors: Clarenbach Jacob J. , Grundy Scott M. , Palacio Natalia , Lena Vega Gloria
Published: February 2008

Low-density lipoprotein cholesterol (LDL-C) is the primary target of lipid-lowering therapy. However, all lipoproteins containing apolipoprotein B (apo B) appear to be atherogenic. Preferred targets of therapy therefore may include either the cholesterol in all apo B-containing lipoproteins (non-high-density lipoprotein cholesterol [non-HDL-C]) or total apo B itself. Apo B can be measured by three methods: chemically, by nuclear magnetic resonance (NMR), and by immunoassay. This study compares the first two methods as a function of the number of metabolic risk factors in patients with metabolic syndrome. Plasma lipid, lipoprotein cholesterol, and apo B levels were measured in 274 adults with varying numbers of metabolic syndrome components. Low-density lipoprotein (LDL) particle sizes were measured by gel electrophoresis and by NMR. Total apo B was estimated chemically and by conversion of NMR lipoprotein particle number, assuming one apo B molecule per lipoprotein particle. As the number of metabolic syndrome components increased, apo B rose by both chemical and NMR methods, but by chemical methods, increases were in the triglyceride-rich fraction, whereas by NMR, they were in LDL. The correlation between total apo B measured by the two methods was only moderate ( r = .73). Further, non-HDL-C was more highly correlated with total apo B measured chemically than either LDL-C or total apo B by NMR. Non-HDL-C correlates highly with total apo B in patients with metabolic syndrome and had advantages as a target of therapy over LDL-C or NMR apo B.
Endothelin-1 in Humans is Increased by Oxygen-Derived Radicals Ex Vivo and in Vivo
Authors: Knappe Dorit , Sill Bjoern , Tharun Bjoern , Koester Ralf , Baldus Stephan , Muenzel Thomas , Meinertz Thomas , Kähler Jan
Published: February 2008

Endothelin-1, angiotensin II, and oxygen-derived radicals are pivotal factors in the development and progression of atherosclerosis. In vitro studies suggest that generation of oxygen-derived radicals by angiotensin II is an important mechanism increasing endothelin-1 synthesis, which consecutively may trigger effects such as cell proliferation and hypertrophy. The aim of this study was to confirm our previous data in an ex vivo and an in vivo setting. Explanted segments of internal mammary arteries were analyzed for big endothelin-1 expression following incubation with xanthine oxidase, angiotensin II, superoxide dismutase, and catalase to stimulate or to specifically inactivate oxygen-derived radicals. Endothelin-1 concentrations were determined by immunostaining and enzyme-linked immunosorbent assay. Further, oxypurinol was given to patients undergoing coronary angioplasty, a procedure known to increase plasma endothelin-1 concentrations. Angiotensin II and xanthine oxidase dose-dependently increased big endothelin-1 concentrations ( p < .01 and p < .0001); the effects could be inhibited by coincubation with superoxide dismutase and catalase as determined by both semiquantitative immunofluorescence and enzyme-linked immunosorbent assay ( p < .01). Patients undergoing coronary angioplasty exhibited significantly elevated big endothelin-1 concentrations 60 minutes after angioplasty ( p = .03); in patients also receiving oxypurinol immediately after angioplasty, big endothelin-1 concentrations decreased ( p = .001). Our results may explain the association between elevated angiotensin II levels, increased oxidative stress, and increased endothelin-1 concentrations in atherosclerosis. The data therefore support the concept that oxygen-derived free radicals stimulate the release of endothelin-1, which subsequently induces effects such as proliferation and enhanced agonist-induced vasoconstriction, previously attributed directly to angiotensin II.
Adenosine Promotion of Cellular Migration in Bronchial Epithelial Cells is Mediated by the Activation of Cyclic Adenosine Monophosphate–Dependent Protein Kinase A
Authors: Allen-Gipson Diane S. , Spurzem Karl , Kolm Nicole , Spurzem John R. , Wyatt Todd A.
Published: February 2008

Migration of neighboring cells into the injury is important for rapid repair of damaged airway epithelium. We previously reported that activation of the A2A receptors (A2AARs) mediates adenosine-stimulated epithelial wound healing, suggesting a role for adenosine in migration. Because A2AAR increases cyclic adenosine monophosphate (cAMP) levels in many cells, we hypothesized that cAMP-dependent protein kinase A (PKA) is involved in adenosine-mediated cellular migration. To test this hypothesis, we stimulated a human bronchial epithelial cell line with adenosine and/or A2AAR agonist (5′-(N-cyclopropyl)-carboxamido-adenosine [CPCA]) in the presence or absence of adenosine deaminase inhibitor (erythro-9-(2-hydroxy-3-nonyl) adenine hydrochloride [EHNA]). Cells treated with adenosine or CPCA demonstrated a concentration-dependent increase in migration. Similar results were observed in the presence and absence of EHNA. To confirm A2A involvement, we pretreated the cells for 1 hour with the A2A receptor antagonist ZM241385 and then stimulated them with either adenosine or CPCA. To elucidate PKA's role, cells were pretreated for 1 hour with either a PKA inhibitor (KT5720) or a cAMP antagonist analogue (Rp-cAMPS) and then stimulated with adenosine and/or CPCA. Pretreatment with KT5720 or Rp-cAMPS resulted in a significant decrease in adenosine-mediated cellular migration. PKA activity confirmed that bronchial epithelial migration requires cAMP and PKA activity. When cells were wounded and stimulated with CPCA, an increase in PKA activity occurred. Pretreatment for 1 hour with either KT5720 or Rp-cAMPS resulted in a significant decrease in adenosine-mediated PKA activation. These data suggest that adenosine activation of A2AAR augments epithelial repair by increasing airway cellular migration by PKA-dependent mechanisms.
Disparities in Cardiovascular Disease Risk and Treatment
Authors: Colleran Kathleen M. , Richards Allyson , Shafer Keri
Published: February 2008

Background

Cardiovascular morbidity and mortality can be prevented by identification and modification of specific risk factors. Ethnic minorities have a higher incidence of cardiovascular risk factors. Additionally, ethnic minorities often reside in medically underserved areas and are subject to health care disparities. We hypothesized that ethnic minorities residing in medically underserved areas would experience greater health care disparities related to cardiovascular disease (CVD) prevention and treatment compared with those residing near an urban academic medical center.

Methods

We performed a retrospective chart review ( N = 200) comparing an urban academic medical center with a rural community center. We evaluated the effects of ethnicity, demographics, and the absence or presence of CVD on cardiovascular risk factor prevalence, risk factor reduction, and CVD prevention and treatment.

Results

We found that Hispanics had more cardiovascular risk factors, including diabetes mellitus and low high-density lipoprotein cholesterol, compared with non-Hispanic whites. However, there were no ethnically based differences in risk factor prevalence by location. Additionally, ethnicity had no impact on the management of cardiovascular risk factors. However, patients with CVD residing in the rural location, regardless of ethnicity, received significantly fewer secondary prevention treatments compared with patients residing near the urban academic medical center, including aspirin or antiplatelets ( p < .0001); beta-blockers or calcium channel blockers ( p ≤ .0001); diuretics, angiotensin-converting enzyme inhibitors, or angiotensin receptor blockers ( p = .014); and statins ( p ≤ .0001).

Conclusions

Hispanics have more CVD risk factors than non-Hispanic whites but receive equivalent prevention initiatives. Residing in a rural, medically underserved area, regardless of ethnicity, was associated with the largest CVD treatment and health care disparity.
An Overlooked Source of Physician-Scientists
Authors: Puljak Livia
Published: February 2008

A shortage of physician-scientists in the United States is an ongoing problem. Various recommendations have been made to address this issue; however, none of them have ameliorated the situation. Foreign medical school graduates with postdoctoral training in the United States are an overlooked and untapped resource for combating the dearth of physician-scientists. Evaluation of the scientific staff at the University of Texas Southwestern Medical Center revealed that 11% of all postdoctoral fellows were international medical graduates. Interestingly, a survey taken by these individuals revealed a lack of institutional and/or mentor support for career development and preparation for becoming physician-scientists. Foreign postdoctoral fellows with medical degrees are not even eligible for physician-scientist grants and awards since they are not US citizens. Although physicians educated in the United States usually matriculate from medical school with high educational debt that prevents most of them from entering into scientific careers, doctors trained outside the United States generally have minimal, if any, debt. Furthermore, many of them have a keen interest in remaining in the United States once they complete their postdoctoral training. Thus, foreign-trained medical professionals who have pursued scientific training in the United States can be one of the solutions for the current dearth of physician-scientists.
Successful Surgical Management of a Ruptured True Pancreaticoduodenal Artery Aneurysm following Failed Transcatheter Embolization
Authors: Sharif Muhammad A. , O'Donnell Mark E. , Johnston Lynn C. , Lau Luk L.
Published: February 2008

A ruptured splanchnic artery aneurysm is a rare clinical entity. Its diagnosis requires a high index of clinical suspicion, and management usually requires a multidisciplinary approach. We present a case of ruptured true pancreaticoduodenal artery aneurysm in an 83-year-old woman who was initially treated with transcatheter embolization, but it failed to arrest the bleeding, and she subsequently required laparotomy and surgical ligation. The clinical course and management are discussed with a review of the literature.
Foam Sclerotherapy for the Treatment of Varicose Veins
Authors: Bergan John , Cheng Van
Published: February 2008

Treatment of venous insufficiency with liquid sclerotherapy is considered by some to be an unfulfilled promise. It was heralded in the first half of the last century to be a replacement for surgery, but as recurrences of varicose veins appeared in limbs treated with injection techniques, surgery reappeared and was dominant in the last half of the century. Just as saphenous stripping was proved to be superior to proximal ligation, both were replaced by use of electromagnetic energy, such as radiofrequency and laser venous ablation, as a means of taking the saphenous veins out of the circulation. Now reports of recurrent varices in 20 to 50% of operated cases are making some physicians look to alternatives in treating varicose veins. Foam sclerotherapy must be looked upon as an entirely new method of treatment. It is useful in all types of varices and is proven to be safe, simple, cheap, reliable, and repeatable.
STAT3 Sensitizes Insulin Signaling by Negatively Regulating Glycogen Synthase Kinase-3β
Authors: Moh Akira , Zhang Wenjun , Yu Sidney , Wang Jun , Xu Xuming , Li Jiliang , Fu Xin-Yuan
Published: February 2008

OBJECTIVE— Glucose homeostasis is achieved by triggering regulation of glycogen synthesis genes in response to insulin when mammals feed, but the underlying molecular mechanism remains largely unknown. The aim of our study was to examine the role of the signal transducers and activators of transcription 3 (STAT3) in insulin signaling.

RESEARCH DESIGN AND METHODS— We generated a strain of mice carrying a targeted disruption of Stat3 gene in the liver (L-Stat3−/− mice). Hepatocytes of the L-Stat3−/− mice were isolated to establish cell lines for mechanistic studies. Nuclear translocation and DNA-protein interaction of STAT3 was analyzed with immunofluorescent and chromatin immunoprecipitation methods, respectively. Levels of glucose, insulin, leptin, and glucagon were profiled, and putative downstream molecules of STAT3 were examined in the presence of various stimuli in L-Stat3−/− and control mice.

RESULTS— STAT3 was found to sensitize the insulin signaling through suppression of GSK-3β, a negative regulator of insulin signaling pathway. During feeding, both mRNA and protein levels of GSK-3β decreased in Stat3f/+ mice, which reflected the need of hepatocytes for insulin to induce glycogen synthesis. In contrast, the L-Stat3−/− mice lost this control and showed a monophasic increase in the GSK-3β level in response to insulin. Administration of GSK-3β inhibitors lithium chloride and L803-mts restored glucose homeostasis and rescued the glucose intolerance and impaired insulin response in L-Stat3−/− mice.

CONCLUSIONS— These data indicate that STAT3 sensitizes insulin signaling by negatively regulating GSK-3β. Inactivation of STAT3 in the liver contributes significantly to the pathogenesis of insulin resistance.
Selective Activation of Peroxisome Proliferator–Activated Receptor (PPAR)α and PPARγ Induces Neoangiogenesis Through a Vascular Endothelial Growth Factor–Dependent Mechanism
Authors: Biscetti Federico , Gaetani Eleonora , Flex Andrea , Aprahamian Tamar , Hopkins Teresa , Straface Giuseppe , Pecorini Giovanni , Stigliano Egidio , Smith Roy C. , Angelini Flavia , Castellot John J. , Pola Roberto
Published: February 2008

OBJECTIVE—Peroxisome proliferator–activated receptors (PPARs) are therapeutic targets for fibrates and thiazolidinediones, which are commonly used to ameliorate hyperlipidemia and hyperglycemia in type 2 diabetes. In this study, we evaluated whether activation of PPARα and PPARγ stimulates neoangiogenesis.

RESEARCH DESIGN AND METHODS—We used selective synthetic PPARα and PPARγ agonists and investigated their angiogenic potentials in vitro and in vivo.

RESULTS—Activation of PPARα and PPARγ leads to endothelial tube formation in an endothelial/interstitial cell co-culture assay. This effect is associated with increased production of the angiogenic cytokine vascular endothelial growth factor (VEGF). Neovascularization also occurs in vivo, when PPARα and PPARγ agonists are used in the murine corneal angiogenic model. No vascular growth is detectable when PPARα and PPARγ agonists are respectively used in PPARα knockout mice and mice treated with a specific PPARγ inhibitor, demonstrating that this angiogenic response is PPAR mediated. PPARα- and PPARγ-induced angiogenesis is associated with local VEGF production and does not differ in extent and morphology from that induced by VEGF. In addition, PPARα- and PPARγ-induced in vitro and in vivo angiogenesis may be significantly decreased by inhibiting VEGF activity. Finally, in corneas treated with PPARα and PPARγ agonists, there is increased phosphorylation of endothelial nitric oxide synthase and Akt.

CONCLUSIONS—These findings demonstrate that PPARα and PPARγ activation stimulates neoangiogenesis through a VEGF-dependent mechanism. Neoangiogenesis is a crucial pathological event in type 2 diabetes. The ability of PPARα and PPARγ agonists to induce neoangiogenesis might have important implications for the clinical and therapeutic management of type 2 diabetes.
Monocyte Chemoattractant Protein-1 Deficiency Fails to Restrain Macrophage Infiltration Into Adipose Tissue
Authors: Kirk Elizabeth A. , Sagawa Zachary K. , McDonald Thomas O. , O'Brien Kevin D. , Heinecke Jay W.
Published: February 2008

OBJECTIVE— Monocyte chemoattractant protein-1 (MCP-1), a CC-motif chemokine, has been proposed to play critical roles in insulin resistance and recruitment of monocytes into adipose tissue. We hypothesized that the absence of MCP-1 would improve the former and diminish the latter.

RESEARCH DESIGN AND METHODS— We investigated these two hypotheses by quantifying glucose metabolism and the accumulation of macrophages in adipose tissue of control and MCP-1–deficient (Mcp1−/−) mice after feeding the animals a high-fat diet for 10 or 16 weeks.

RESULTS— We first established that the two strains were in the same genetic background and that macrophage recruitment into inflamed peritoneum was markedly reduced in the MCP-1–deficient animals. In striking contrast, independent studies at two different facilities at either an early or late time point failed to detect any impairment in macrophage accumulation in adipose tissue of fat-fed Mcp1−/− mice. Immunoblot analysis revealed higher levels of Mac2, a macrophage-specific protein, in multiple fat depots of Mcp1−/− mice fed a high-fat diet. These mice also had significantly more adipose tissue than control mice, but their glucose metabolism was similar.

CONCLUSIONS— Our observations suggest that MCP-1 does not play a prominent a role in promoting macrophage recruitment into adipose tissue or in systemic insulin resistance.
Radiographic assessment of the sinuses in patients treated for nasopharyngeal carcinoma
Authors: Raviv Joseph , Downing Lance , Le Quynh-Thu , Hwang Peter
Published: February 2008

Introduction

Patients undergoing therapy for nasopharyngeal carcinoma (NPC) often experience dysfunction of the sinonasal mucosa as a side effect of radiotherapy and chemotherapy. Sinonasal mucosal changes may vary throughout the treatment and posttreatment periods, but little objective data exist characterizing such changes. We evaluated serial radiologic changes of the paranasal sinus mucosa in patients with NPC undergoing treatment.

Methods

Medical and radiographic records were reviewed for all patients treated for NPC between 2004 and 2006 at Stanford University Medical Center. Pretreatment computed tomography (CT) images served as the baseline images for comparison, and posttreatment CT and magnetic resonance imaging (MRI) images were categorized temporally into 3-month intervals, up to 25 months after initiation of treatment. Images were scored in a blinded fashion using the Lund-Mackay (LM) staging system.

Results

Thirty-five patients received treatment for NPC during the study period, of whom 27 had adequate data for analysis and inclusion in the study. The mean pretreatment LM score was 1.41, and a statistically significant increase in LM score was observed at 3, 6, 9, 12, 15, and 18, 22, and 28 months. There was continued progression of radiologic sinus opacification over the first 30 months after treatment.

Conclusions

The treatment of NPC with radiotherapy and chemotherapy is associated with radiologic evidence of sinus mucosal thickening. The extent of mucosal thickening can be expected to progress after treatment for up to 30 months. Patients undergoing treatment for NPC should be monitored carefully throughout the posttreatment period for clinical manifestations of dysfunctional sinonasal mucosa.
Absorbable Biomaterials used within Paranasal Sinuses: An Animal Study
Authors: Stumpe Matthew R. , Handorf Charles , Thompson Jerome W. , Chandra Rakesh K.
Published: February 2008

Background

The purpose of this study was to investigate the quality of mucosal regeneration in the presence of two different resorbable dressings derived from hyaluronic acid (HA): HA-carboxymethyl cellulose (HACMC) and esterified HA (HYAFF). A prospective randomized animal study was performed.

Methods

Twelve New Zealand white rabbits underwent bilateral maxillary sinusomy via a canine fossa approach. Each sinus was stripped circumferentially, except for the mucosa along the medial wall in the region of the natural ostium. Each of the 24 sinuses was then packed with either HACMC (n = 8) or HYAFF (n = 8) or left as an unpacked control (n = 8). After 14 days, each animal was killed and the sinus contents were evaluated histologically by a blinded pathologist.

Results

Criteria for optimal mucosal regeneration included a continuous layer of ciliated columnar epithelium with normal-appearing submucous glands and lack of both inflammatory infiltrate and fibrosis. Optimal regeneration was observed in 5/8 (62.5%) of the HACMC specimens, 1/8 (12.5%) of the HYAFF specimens, and 6/8 (75%) of the controls. The trend toward optimal regeneration using either HACMC or control was statistically significant when compared with HYAFF (p = 0.03). HYAFF specimens also were more likely to exhibit atrophic subepithelial glands in the regenerated mucosa. Polarizable foreign material was observed in 1/8 (12.5%) of the HACMC specimens and 2/8 (25%) of the HYAFF specimens.

Conclusion

The quality of epithelial regeneration is potentially affected by the form of HA present in the healing milieu. In this series, the most optimal healing characteristics were seen in unpacked controls. Between the preparations of HA studied, HACMC exhibited more favorable healing patterns, which were nearly similar to controls.
Anterior Palate Sensory Impairment after Septal Surgery
Authors: Chandra Rakesh K. , Rohman Grant T. , Walsh William E.
Published: February 2008

Background

This study was performed to present a series of patients who experienced anterior palatal sensory impairment after nasal septal surgery. This phenomenon has not been reported in the English literature to date.

Methods

We reviewed 107 septal surgeries done by the same surgeon over a 3-year period. One hundred one surgeries were septoplasty by technique of submucous resection, three surgeries were septal perforation repairs using a mucosal advancement flap from the nasal floor, two surgeries were excisions of benign septal neoplasms, and one surgery was a closed reduction of a nasal septal fracture.

Results

Overall, 3/107 patients (2.8%) experienced postoperative numbness of the anterior palate. Two of these patients underwent septoplasty, and the third patients underwent repair of septal perforation. A chisel was used to resect a portion of the maxillary crest posterior to the nasal spine in 11 patients, including the 3 patients who reported postoperative numbness. Suction cautery was also used in one of the 3 patients to address bleeding of the nasopalatine artery. Two patients reported concomitant palatal paresthesias with numbness, and both had recovery of normal sensation at 3 months follow-up. The third patient, in whom cautery was used, continued to experience numbness 1 year postoperatively.

Conclusion

Sensory impairment of the anterior palate may result from surgery of the nasal septum and appears to be associated with chisel of the maxillary crest. Cautery should be avoided near the nasopalatine foramen. The relevant surgical anatomy of the nasopalatine nerve is reviewed and discussed in the context of these cases.
Patients with Positive Allergen Test have Less Favorable Outcome after Endoscopic Microdebrider-assisted Inferior Turbinoplasty
Authors: Wu Chen-Chi , Lee Shiann-Yann , Hsu Chuan-Jen , Yeh Te-Huei
Published: February 2008

Background

Endoscopic microdebrider–assisted inferior turbinoplasty is a newly developed surgical technique to treat patients with nasal obstruction. Although the procedure has been reported to be safe and effective, we tested the hypothesis that the prognosis might deteriorate with time in allergic rhinitis patients as identified by a positive allergen test in patients who have a persistent regional inflammation of the nose. We assessed the degree of nasal obstruction in a prospective cohort to investigate whether positive allergen test predicts outcome.

Methods

In 70 consecutive patients, the symptom of nasal obstruction was evaluated subjectively by a visual analog scale (VAS) and objectively by acoustic rhinometry using cross-sectional area of the second notch (CSA-2) and nasal cavity volume before operation, and 3 months, 12 months after operation, respectively. Then, patients were classified and compared according to the multiple-antigen simultaneous test (MAST).

Results

Both MAST+ and MAST− groups showed statistically significant improvement in VAS score, CSA-2, and nasal cavity volume at 12 months after operation (p < 0.01). Of note, MAST+ patients showed less favorable results than MAST− patients at 12 months after operation (p < 0.05).

Conclusion

Microdebrider-assisted inferior turbinoplasty provides effective relief for patients with nasal obstruction. However, such turbinate surgery may be successful only for a short period of time in patients with allergic rhinitis. Our finding suggests that, in selecting appropriate candidates, surgeons should consider criteria other than symptomatology, especially in patients with allergic rhinitis who may have manifestations other than at the level of the inferior turbinate contributing to nasal blockage.
Effects of Nasal Surgery on Sleep Quality in Obstructive Sleep Apnea Syndrome with Nasal Obstruction
Authors: Nakata Seiichi , Noda Akiko , Yasuma Fumihiko , Morinaga Mami , Sugiura Makoto , Katayama Naomi , Sawaki Mine , Teranishi Masaaki , Nakashima Tsutomu
Published: February 2008

Background

The purpose of this study was to evaluate the effects of nasal surgery on nasal resistance, sleep apnea, and sleep quality in adult male patients with obstructive sleep apnea syndrome (OSAS). A prospective study was performed in OSAS patients who underwent isolated nasal surgery in a tertiary referral center.

Methods

During the 3-year study period, 49 OSAS patients suffering from symptomatic nasal obstruction/impaired nasal breathing underwent the standard polysomnography before and after surgery. Polysomnography along with measures of nasal resistance and daytime sleepiness (the Epworth sleepiness scale [ESS] scores) were reviewed also.

Results

Surgery decreased the nasal resistance (0.55 ± 0.37 Pa/cm3 per second versus 0.17 ± 0.19 Pa/cm3 per second; p < 0.001) and ESS scores (11.7 ± 4.1 versus 3.3 ± 1.3; p < 0.001), without changes in the apnea-hypopnea index (AHI; 44.6 ± 22.5 versus 42.5 ± 22.0). Surgery increased nadir oxygen saturation (76.2 ± 10.9% versus 78.8 ± 8.1%; p < 0.01), shortened apnea–hypopnea duration (averaged/maximum; 33.5 ± 7.3/61.1 ± 46.0 versus 28.8 ± 7.4/47.3 ± 36.1 second; p < 0.05/p < 0.01), and improved sleep quality.

Conclusion

The results suggest that nasal surgery is useful for lowering nasal resistance, ameliorating sleep-disordered breathing, and improving sleep quality and daytime sleepiness in OSAS.
Baby Shampoo Nasal Irrigations for the Symptomatic Post-functional Endoscopic Sinus Surgery Patient
Authors: Chiu Alexander G. , Palmer James N. , Woodworth Bradford A. , Doghramji Laurel , Cohen Michael B. , Prince Anthony , Cohen Noam A.
Published: February 2008

Background

Symptoms of postnasal drainage and thickened mucus are commonly seen in patients with chronic rhinosinusitis (CRS) recalcitrant to sinus surgery and conventional medical therapies. Chemical surfactants can act as a mucolytic by reducing water surface tension and have the potential to serve as an antimicrobial agent. Baby shampoo is an inexpensive, commercially available solution containing multiple chemical surfactants. This is an in vitro study of its antimicrobial effects on Pseudomonas biofilms with translation to a clinical study for use as an adjuvant nasal wash in patients with CRS who remain symptomatic despite adequate sinus surgery and conventional medical therapies.

Methods

In vitro testing was performed to determine the optimal concentration of baby shampoo that disrupted preformed bacterial biofilms and inhibited biofilm formation. This concentration was then used in a prospective study of symptomatic post–functional endoscopic sinus surgery (FESS) patients who irrigated twice a day for 4 weeks. Validated outcome forms and objective smell testing was performed before and after therapy.

Results

One percent baby shampoo in normal saline was the optimal concentration for inhibition of Pseudomonas biofilm formation. Baby shampoo had no effect on the eradication of preformed Pseudomonas biofilms. Eighteen patients with CRS with an average of 2.8 surgeries were studied after irrigating with 1% baby shampoo solution. Two patients discontinued use because of minor nasal and skin irritations; 46.6% of patients experienced an overall improvement in their subjective symptoms, and 60% of patients noted improvement in specific symptoms of thickened mucus and postnasal drainage.

Conclusion

Baby shampoo nasal irrigation has promise as an inexpensive, tolerable adjuvant to conventional medical therapies for symptomatic patients after FESS. Its greatest benefit may be in improving symptoms of thickened nasal discharge and postnasal drainage.
Anatomical Reconstruction from Endoscopic Images: Toward Quantitative Endoscopy
Authors: Wang Hanzi , Mirota Daniel , Hager Gregory , Ishii Masaru
Published: February 2008

Background

Recent advances in computational image processing have made it possible to reconstruct camera motion and scene geometry from a series of monocular images. By applying these methods to endoscopic image sequences, it is possible to create detailed, quantitative anatomic reconstructions. Such anatomic reconstructions have many potential clinical uses. Our objectives in this study are to (1) develop a process flow for reconstruction from endoscopic image sequences and (2) present results supporting the hypothesis that such reconstructions can be computed.

Methods

We first outline the overall process flow for endoscopic reconstruction. Then, we present an instantiation of this process flow using recently developed methods in computational vision. We apply these methods to cadaverous specimens for which ground truth endoscopic motion is known.

Results

We are able to produce consistent estimates of endoscopic motion and dense reconstructions of the surrounding anatomy for >65% of 1373 image pairs.

Conclusion

Our study indicates that processing endoscopic images to produce anatomic structure is feasible. Such reconstructions have high potential clinical value for intraoperative navigation, diagnosis, and treatment planning.
A numerical study of grain size effects on the strength and elongation of Al polycrystals using strain gradient plasticity theory
Authors: Zhou L. , Li S. X. , Ke W.
Published: February 2008

By incorporating the constitutive equations based on classical plasticity and the mechanism-based strain gradient plasticity with finite element software, the stress–strain relationships and uniform elongations of Al polycrystals with different grain sizes were studied numerically. The calculation results indicate that grain refinement cannot substantially improve the uniform elongation but can increase the yield strength of Al polycrystals when the grain size is of the order of the micron and submicron scale. The Hall–Petch relationship for yield strength holds and the uniform elongation decreases with decreasing grain size. The calculation results in general agree well with the experiment data.
The anisotropy of deformation for friction stir processed Mg alloy due to the existence of onion rings
Authors: Xinghao Du , Baolin Wu
Published: February 2008

In the present study, it is found that one-pass friction stir processed AZ61 alloy exhibits inferior deformation ability along the longitudinal direction compared with the transverse direction at high temperatures. Based on observation of microstructure and fracture surface, premature onion ring splitting is suggested to be mainly responsible for this anisotropy of deformation behavior. Furthermore, the homogeneous microstructure from multi-pass friction stir processing can cure the premature onion ring splitting and then exhibit isotropic high-temperature superplastic deformation behavior.
A study of the Si-phase growth mechanismin thixocast (A356) alloy during hot deformation
Authors: Haghshenas M. , Zarei-Hanzaki A. , Fatemi-Varzaneh S. M.
Published: February 2008

The microstructure in modified semi-solid thixocast (A356) alloy consists of an α-Al phase with an Al/Si eutectic structure. The silicon phase in the eutectic structure is coral-like with fine fibers. The lack of good ductility in this alloy is related to the presence of silicon fibers. Accordingly, many investigations have been recently conducted to modify the Si morphology through thermomechanical processing on this alloy. In the present work, a thixocast (A356) alloy was deformed at 450 °C, 500 °C and 540 °C through different strain rates. Consequently the silicon fibers were broken into small particles. The results indicated that the Si particles might coarsen at 540 °C when deformed by rates of 0.0005 s−1 and 0.0001 s−1.
The morphology of nitrided iron–chromium alloys; influence of chromium content and nitrogen supersaturation
Authors: Díaz Nicolás Emiliano Vives , Schacherl Ralf Erich , Mittemeijer Eric Jan
Published: February 2008

Different iron–chromium alloys (4, 8, 13 and 20 wt.% Cr) were nitrided in NH3/H2 gas mixtures at 580°C. The nitrided microstructure was investigated by X-ray diffraction, light microscopy, hardness measurements and scanning electron microscopy. Composition depth-profiles of the nitrided zone were determined by electron probe microanalysis. Various microstructures develop, depending on the nitriding conditions and the alloy composition (chromium content). The initial development of coherent, sub-microscopical CrN nitrides leads to a state of hydrostatic stress allowing the uptake of excess nitrogen dissolved in the ferrite matrix. It is shown that the outcome of the subsequent discontinuous coarsening process, which leads to a lamellar microstructure, has a close relation to the nitrogen supersaturation. As a result, the occurrence of a distinct gradient in hardness across the nitrided zone can be understood.
Experimental study of the phase relations in the Fe–Zn–Cr system at 600°C
Authors: Ai Meirong , Yin Fucheng , Liu Ya , Wang Xinming , Zhao Manxiu , Su Xuping
Published: February 2008

The isothermal section of the Fe–Zn–Cr ternary system at 600 °C was determined using equilibrated alloys with the aid of a diffusion couple approach. The specimens were investigated by means of scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, electron probe microanalysis and X-ray diffraction. The results showed that (Cr) is in equilibrium with all phases in the system except (α-Fe). A ternary phase with an approximate formula of Fe18Zn79Cr3 was found. The composition ranges of all intermetallic phases in the system were determined. The solubility of Zn in (Cr) is about 2.5 at.%, and that of Cr in the δ, Γ and liquid zinc is 3.1, 5.4 and 1.4 at.%, respectively.
Thermodynamic description of the ternary Pd–Sn–Zn system
Authors: Li Zuoan , Knott Sabine , Mikula Adolf
Published: February 2008

The thermodynamic properties of the liquid Pd–Sn–Zn ternary system were investigated, because the Sn–Zn alloy is a promising lead-free solder and Pd can be used as a substrate material. Using an appropriate galvanic cell, the partial free energies of Zn in liquid Pd–Sn–Zn alloys were determined as a function of concentration and temperature. Thermodynamic properties were obtained for 18 alloys. Their composition was situated on two cross-sections with the constant molar ratios of Pd: Sn = 1:3 and 1:9. The integral Gibbs free energy and the integral enthalpy for the ternary system at 1000 K were calculated by Gibbs–Duhem integration. For the liquid binary Pd–Sn system, some inconsistencies were found in previous CALPHAD results. Considering the latest experimental information, the interaction parameters of the liquid phase were reevaluated. The liquidus temperatures were also determined from EMF measurements.
Cover Picture: Nano‐characterization of Cast Structures by FIB‐Tomography (Adv. Eng. Mater. 01‐02/2008)
Authors: Lasagni F. , Lasagni A. , Engstler M. , Degischer H. P. , Mücklich F.
Published: February 2008

The cover shows the 3D‐FIB reconstruction of an AlSi8Mg5 alloy with: AlFeSiMg aluminides (red), Mg2Si Chinese script (yellow∥, and Si lamellae (cyan/Al‐transparent). The “tomograph” was obtained using SE‐images for drawing the particle contours and low resolution EDS maps for phase identification (analyzed volume [xyz] = 14.0 × 7.9 × 7.0 μm3). More details can be found in the article by F. Lasagni et al. on page 62.
Organic Nanoclusters on Inorganic Nanostructures for Tailoring the Emission Properties of Organic Materials
Authors: Ng Alan Man‐Ching , Djurišić Aleksandra B. , Tam Kai‐Hang , Kwok Wai‐Ming , Chan Wai‐Kin , Tam Wing Yan , Phillips David Lee , Cheah Kok‐Wai
Published: February 2008

Inorganic nanostructures have been intensively studied because of their size‐dependent emission color as a result of quantum confinement effects. In contrast, no significant size dependence of the optical properties is expected for organic nanostructures owing to the weak nearest‐neighbor interactions in molecular crystals; however, the optical properties of organic materials can be significantly affected by aggregation and molecular packing, which can result in large differences between the emission spectra of solutions and thin films. Thus, the emission spectra of organic nanostructures may differ considerably from the bulk material despite the absence of quantum confinement effects. We demonstrate that 3,4,9,10‐perylenetetracarboxylicdiimide (PTCDI) nanoclusters grown on ZnO nanorods exhibit an intense blue‐white photoluminescence, different from the weak red emission of PTCDI films. Light emitting diodes consisting of ZnO nanorods and PTCDI nanoclusters also exhibited white emission.
Tuning the Rate‐Dependent Stiffness of Materials by Exploiting Néel Relaxation of Magnetic Nanoparticles
Authors: Singh Harpreet , Wang Mao , Rutledge Gregory C. , Hatton T. Alan
Published: February 2008

The effective stiffness of materials that are impregnated with magnetic nanoparticles can be modulated by magnetic fields if the nanoparticle Néel relaxation rates are slower than the characteristic deformation rates. A numerical analysis indicates that the deflection of magnetic dipoles against the applied magnetic field on deformation of the material provides the energy absorption necessary for the enhanced stiffness observed in drop ball impact tests. The penetration depth, fraction of the impact energy that is absorbed by the rotating dipoles, and the effective increase in stiffness are shown to depend uniquely on the ratio of the characteristic magnetic energy density relative to the elastic energy density, and on the shape of the impacting object.