bluuebunny/crossref_metadata_2025 huggingface dataset:
Autoimmune pancreatitis
Authors: Igaz Péter , Tulassay Zsolt
Published: May 2008

Az autoimmun pancreatitis a krónikus pancreatitis ritka oka. Klinikai jelentősége mégsem lebecsülendő, mivel részben a rosszindulatú hasnyálmirigyráktól történő elkülönítése nehézséget okozhat, részben pedig az idült pancreatitisek többségétől eltérően jól kezelhető, szteroidkezelésre teljes regressziója is előfordulhat. Klinikai képe nem jellegzetes, az elzáródásos sárgaság, hasi fájdalom, fogyás gyakori. A képalkotó vizsgálatok jellemzően a pancreas diffúz megnagyobbodását és a Wirsung-vezeték egyenetlen szűkületét mutatják. Autoimmun pancreatitisben szenvedőkben az IgG4-immunglobulin növekedett szérumkoncentrációját, autoantitesteket és IgG4-pozitív immunsejtek jelenlétét mutatták ki más szövettani jellegzetességek mellett. A hasnyálmirigy érintettsége mellett egyéb szervek is megbetegedhetnek, így pl. sclerotisáló cholangitisszel, sialoadenitisszel, retroperitonealis fibrosissal, Riedel-strumával és gyulladásos bélbetegségekkel való társulását is leírták. Mindezek alapján az autoimmun pancreatitis rendszerbetegségnek tartható, szisztémás IgG4-asszociált sclerotisáló kórkép egyik megjelenési formájaként.
Release Mortality of Undersized Fish from the Snapper–Grouper Complex off the North Carolina Coast
Authors: Overton Anthony S. , Zabawski John , Riley Kenneth L.
Published: May 2008

Red porgy Pagrus pagrus, scamps Mycteroperca phenax, and gags M. microlepis support valuable recreational and commercial fisheries in North Carolina. Fish in the snapper–grouper complex are managed to prevent overfishing and maintain a stable spawning stock. We investigated postrelease mortality of 263 undersized red porgy, scamps, and gags that were captured by angling and subjected to short-term (2 h) and long-term (48 h) holding experiments. Fish were caught at depths ranging from 15 to 45 m using traditional bottom-fishing hook-and-line gear. Catch per unit effort ranged from 0.11 to 1.80 fish/rod-hour (FRH) for sublegal-sized fish and from 0.06 to 0.50 FRH for legal-sized fish. Nontarget species predominated in the catch (N = 1,135), but the red porgy was the most frequently caught individual species (N = 196). The effects of short-term (2-h) holding within species were similar between fish held in different locations (oxygenated live well or cage anchored to the seafloor); mortality did not differ between the two holding location groups. Mortality of fish subjected to short-term holding in the live well was 6.1%; mortality of fish in the submerged cage was 10.5% for the 2-h holding period and 12.3% for the 48-h holding period. There was no significant effect of anatomical hook location on mortality of gags or scamps. However, hook location significantly affected survival of red porgy; individuals hooked in the lip were 11.34 times more likely to survive than fish hooked in other locations. The results of this study suggest that short-term holding is appropriate for assessing mortality of undersized fish caught offshore in a hook-and-line fishery.
Association of the GABRB3 Gene with Nonsyndromic Oral Clefts
Authors: Inoue Hiroki , Kayano Shuji , Aoki Yoko , Kure Shigeo , Yamada Atsushi , Hata Akira , Matsubara Yoichi , Suzuki Yoichi
Published: May 2008

Objective:

Nonsyndromic oral clefts are common craniofacial anomalies classified into two subgroups: cleft lip with or without cleft palate and isolated cleft palate. Nonsyndromic oral clefts are multifactorial diseases, with both genetic and environmental factors involved in their pathogenesis. The inhibitory neurotransmitter, γ-aminobutyric acid plays a role in normal embryonic, and particularly facial, development and γ-aminobutyric acid receptor type A β-3 subunit (GABRB3) knockout mice have been shown to have cleft palate. The GABRB3 gene is therefore a strong candidate gene for nonsyndromic oral clefts. We investigated here whether genetic variations of the GABRB3 gene affect the risk for nonsyndromic oral clefts.

Method:

In this case-control study, a total of 178 Japanese patients with cleft lip with or without cleft palate and 374 unrelated controls were recruited and were genotyped for six single nucleotide polymorphisms and a dinucleotide repeat marker of the GABRB3 gene.

Results:

None of the single nucleotide polymorphisms showed complete linkage disequilibrium with other single nucleotide polymorphisms. In a case-control association study with the six-locus haplotype of the gene, TGTGCT haplotype frequency in patients with cleft lip with or without cleft palate was significantly higher than in the controls (corrected p value = .029). None of the alleles of the dinucleotide repeat marker showed significant association with cleft lip with or without cleft palate.

Conclusions:

Our data suggest that the GABRB3 gene is involved in the pathogenesis of cleft lip with or without cleft palate in the Japanese population.
Timing of Palatal Surgery and Speech Outcome
Authors: Chapman Kathy L. , Hardin-Jones Mary A. , Goldstein Jeffrey A. , Halter Kelli Ann , Havlik Robert J. , Schulte Julie
Published: May 2008

Objective:

To examine the impact of age and lexical status at the time of primary palatal surgery on speech outcome of preschoolers with cleft palate.

Participants:

Forty children (33 to 42 months) with nonsyndromic cleft palate participated in the study. Twenty children (Group 1) were less lexically advanced and younger (mean age  =  11 months) and 20 children (Group 2) were more lexically advanced and older (mean age  =  15 months) when palatal surgery was performed.

Main Outcome Measures:

Samples of the children's spontaneous speech were compared on 11 speech production measures (e.g., size of consonant inventory, total consonants correct, % correct for manner of articulation categories, compensatory articulation usage, etc.). Next, listeners rated a 30-second sample of each child's connected speech for articulation proficiency and hypernasality, separately, using direct magnitude estimation (DME).

Results:

Group differences were noted for 4 of the 11 speech production measures. Children in Group 1 exhibited larger consonant inventories (and true consonant inventories) and more accurate production of nasals and liquids compared to children in Group 2. On the DME task, significant group differences were found for ratings of articulation proficiency and hypernasality. Children in Group 1 exhibited better articulation and less hypernasality than children in Group 2.

Conclusions:

The findings suggested that children who were less lexically advanced and younger at the time of palatal surgery exhibited better articulation and resonance outcomes at 3 years of age.
Seasonal effects of central leptin infusion on secretion of melatonin and prolactin and on SOCS-3 gene expression in ewes
Authors: Zieba D A , Szczesna M , Klocek-Gorka B , Molik E , Misztal T , Williams G L , Romanowicz K , Stepien E , Keisler D H , Murawski M
Published: May 2008

Recent studies have demonstrated photoperiodic changes in leptin sensitivity of seasonal mammals. Herein, we examined the interaction of season (long days (LD) versus short days (SD)) and recombinant ovine leptin (roleptin) on secretion of melatonin and prolactin (PRL) and on mRNA expression of suppressor of cytokine signaling-3 (SOCS-3) in the medial basal hypothalamus (MBH) in sheep. Twenty-four Polish Longwool ewes, surgically fitted with third ventricle (IIIV) cannulas, were utilized in a replicated switchback design involving 12 ewes per season. Within-season and replicate ewes were assigned randomly to one of three treatments (four ewes/treatment) and infused centrally three times at 0, 1 and 2 h beginning at sunset. Treatments were 1) control, Ringer–Locke buffer; 2) L1, roleptin, 0.5 μg/kg BW; and 3) L2, roleptin, 1.0 μg/kg BW. Jugular blood samples were collected at 15-min intervals beginning immediately before the start of infusions and continued for 6 h. At the end of blood sampling, a washout period of at least 3 days elapsed before ewes were re-randomized and treated with one of the treatments described above (four ewes/treatment). Ewes were then killed and brains were collected for MBH processing. Leptin treatments increased (P<0.001) circulating leptin concentrations compared with controls during both seasons in a dose-dependent manner. Overall, mean plasma concentrations of melatonin were greater (P<0.001) during LD than SD. However, leptin treatments increased melatonin concentrations during SD in a dose-dependent manner and decreased it during LD. Similarly, plasma concentrations of PRL were greater (P<0.001) during LD than SD. However, unlike changes in melatonin, circulating PRL decreased (P<0.001) in response to leptin during LD. Semi-quantitative PCR revealed that leptin increased (P<0.001) SOCS-3 expression in the MBH region during LD in a dose-dependent manner. Data provide evidence that secretion of photoperiodic hormones such as melatonin and PRL are inversely regulated by leptin during SD and LD. However, the increase in expression of SOCS-3 in the MBH during LD compared with SD fails to fully explain these effects.
Platelet‐Rich Plasma and Connective Tissue Grafts in the Treatment of Gingival Recessions: A Histometric Study in Dogs
Authors: Suaid Fabricia Ferreira , Carvalho Marcelo Diniz , Santamaria Mauro Pedrine , Casati Marcio Zaffalon , Nociti Francisco Humberto , Sallum Antonio Wilson , Sallum Enilson Antônio
Published: May 2008

Background: The aim of this study was to histometrically evaluate the healing process of gingival recessions treated with platelet‐rich plasma (PRP) in combination with a subepithelial connective tissue graft (SCTG) and to compare it to that obtained with SCTG alone.

Methods: Six mongrel dogs were used in the experiment. Gingival recessions (5 × 7 mm) were surgically created and exposed to plaque accumulation for 1 month. Contralateral defects were randomly assigned to the test group (SCTG + PRP) or the control group (SCTG). Dogs were sacrificed 45 days after the surgeries, and the blocks containing the experimental specimens were processed for histologic analysis. The histometric parameters evaluated were length of sulcular and junctional epithelium, connective tissue adaptation, new cementum, new bone, and defect extension.

Results: A greater length of new cementum was observed in the sites treated with PRP (2.18 ± 0.78 mm) compared to the control group (1.19 ± 0.62 mm) (P ≤0.05). No statistically significant differences were observed in the remaining parameters. The extension of total epithelium (sulcular and junctional epithelium) was 2.04 ± 0.57 mm for the test group and 2.49 ± 0.82 mm for the control group. The new connective tissue adjacent to the root without cementum formation was 0.29 ± 0.28 mm and 0.23 ± 0.18 mm for the test and control groups, respectively. Bone position was −0.57 ± 0.95 mm for the test group and −0.46 ± 1.34 mm for the control group.

Conclusion: Within the limits of this study, the combination of PRP with SCTG was more effective in promoting new cementum formation than the graft alone.
A Rare Case of Malignant Fibrous Histiocytoma of the Gingiva
Authors: Agnihotri Rupali , Bhat K. Mahalinga , Bhat G. Subraya
Published: May 2008

Background: Malignant fibrous histiocytoma (MFH) is an aggressive, high‐grade tumor with poor prognosis. It is the most common soft tissue sarcoma in adults, usually occurring retroperitoneally in extremities. MFH of the head and neck is rare. Cases with primary involvement of only the oral soft tissues have been reported; a few occurred in the gingiva. Its clinical features include a painless enlarging mass, which may or may not be ulcerated.

Methods: A 20‐year‐old female patient presented with a non‐healing necrotic ulceration of 4 months’ duration on the maxillary anterior labial gingiva. Based on her history and agricultural background, a provisional diagnosis of chronic fungal and chronic bacterial infection was given. The patient was placed on a topical antifungal in combination with antibiotic therapy for 10 days. Because the lesion failed to respond to the initial therapy, an incisional biopsy was performed. The lesion was diagnosed as MFH based on clinical, histopathologic, and immunohistochemical findings.

Results: The patient was referred to the Department of Oncology and Oral and Maxillofacial Surgery, Manipal College of Dental Sciences, Manipal, for further evaluation and treatment; the lesion was treated by resection of the premaxilla, and a splint was placed. She was followed up for 3 months with improvement in her condition.

Conclusions: Because MFH is rare in the oral cavity, misdiagnosis may not be unusual based on the initial clinical examination. Any suspicious lesion that is unresponsive to treatment must be subjected to histopathologic evaluation to arrive at a final diagnosis.
Treatment of Periodontal Intrabony Defects With Demineralized Freeze‐Dried Bone Allograft in Combination With Platelet‐Rich Plasma: A Comparative Clinical Trial
Authors: Piemontese Matteo , Aspriello Simone Domenico , Rubini Corrado , Ferrante Luigi , Procaccini Maurizio
Published: May 2008

Background: The aim of the present randomized, double‐masked, clinical trial was to compare platelet‐rich plasma (PRP) combined with a demineralized freeze‐dried bone allograft (DFDBA) to DFDBA mixed with a saline solution in the treatment of human intrabony defects.

Methods: Sixty interproximal intrabony osseous defects in 60 healthy, non‐smoking subjects diagnosed with chronic periodontitis were treated in this study. Thirty subjects each were randomly assigned to the test group (PRP + DFDBA) or the control group (DFDBA + saline). Clinical and radiographic measurements were made at baseline and at the 12‐month evaluation.

Results: Compared to baseline, the 12‐month results indicated that both treatment modalities resulted in significant changes in all clinical parameters (gingival index, bleeding on probing, probing depth, clinical attachment level, and gingival recession; P <0.001) and radiographic parameters (hard tissue fill and bone depth reduction; P <0.001). However, the test group exhibited statistically significantly greater changes compared to the control group in probing depth reduction (4.3 ± 1.7 mm versus 2.6 ± 2.2 mm; P <0.05) and clinical attachment gain (3.5 ± 2.1 mm versus 2.3 ± 2.4 mm; P <0.001).

Conclusions: Treatment with a combination of PRP and DFDBA led to a significantly greater clinical improvement in intrabony periodontal defects compared to DFDBA with saline. No statistically significant differences were observed in the hard tissue response between the two treatment groups, which confirmed that PRP had no effect on hard tissue fill or gain in new hard tissue formation.
Simulated Fate and Transport of Metolachlor in the Unsaturated Zone, Maryland, USA
Authors: Bayless E. Randall , Capel Paul D. , Barbash Jack E. , Webb Richard M. T. , Hancock Tracy L. Connell , Lampe David C.
Published: May 2008

An unsaturated‐zone transport model was used to examine the transport and fate of metolachlor applied to an agricultural site in Maryland, USA. The study site was instrumented to collect data on soil‐water content, soil‐water potential, ground water levels, major ions, pesticides, and nutrients from the unsaturated zone during 2002–2004. The data set was enhanced with site‐specific information describing weather, soils, and agricultural practices. The Root Zone Water Quality Model was used to simulate physical, chemical, and biological processes occurring in the unsaturated zone. Model calibration to bromide tracer concentrations indicated flow occurred through the soil matix. Simulated recharge rates were within the measured range of values. The pesticide transport model was calibrated to the intensive data collection period (2002–2004), and the calibrated model was then used to simulate the period 1984 through 2004 to examine the impact of sustained agricultural management practices on the concentrations of metolachlor and its degradates at the study site. Simulation results indicated that metolachlor degrades rapidly in the root zone but that the degradates are transported to depth in measurable quantities. Simulations indicated that degradate transport is strongly related to the duration of sustained use of metolachlor and the extent of biodegradation.
Herbicide Sorption Coefficients in Relation to Soil Properties and Terrain Attributes on a Cultivated Prairie
Authors: Farenhorst A. , Papiernik S. K. , Saiyed I. , Messing P. , Stephens K. D. , Schumacher J. A. , Lobb D. A. , Li S. , Lindstrom M. J. , Schumacher T. E.
Published: May 2008

The sorption of 2,4‐D and glyphosate herbicides in soil was quantified for 287 surface soils (0–15 cm) collected in a 10 × 10 m grid across a heavily eroded, undulating, calcareous prairie landscape. Other variables that were determined included soil carbonate content, soil pH, soil organic carbon content (SOC), soil texture, soil loss or gain by tillage and water erosion, and selected terrain attributes and landform segments. The 2,4‐D sorption coefficient (Kd) was significantly associated with soil carbonate content (−0.66;P< 0.001), soil pH (−0.63;P< 0.001), and SOC (0.47;P< 0.001). Upper slopes were strongly eroded and thus had a significantly greater soil carbonate content and less SOC compared with lower slopes that were in soil accumulation zones. The 2,4‐D Kdwas almost twice as small in upper slopes than in lower slopes. The 2,4‐D Kdwas also significantly associated with nine terrain attributes, particularly with compounded topographic index (0.59;P< 0.001), gradient (−0.48;P< 0.001), mean curvature (−0.43;P< 0.001), and plan curvature (−0.42P< 0.001). Regression equations were generated to estimate herbicide sorption in soils. The predicted power of these equations increased for 2,4‐D when selected terrain attributes were combined with soil properties. In contrast, the variation of glyphosate sorption across the field was much less dependent on our measured soil properties and calculated terrain attributes. We conclude that the integration of terrain attributes or landform segments in pesticide fate modeling is more advantageous for herbicides such as 2,4‐D, whose sorption to soil is weak and influenced by subtle changes in soil properties, than for herbicides such as glyphosate that are strongly bound to soil regardless of soil properties.
Occurrence and Fate of Pesticides in Four Contrasting Agricultural Settings in the United States
Authors: Steele Gregory V. , Johnson Henry M. , Sandstrom Mark W. , Capel Paul D. , Barbash Jack E.
Published: May 2008

Occurrence and fate of 45 pesticides and 40 pesticide degradates were investigated in four contrasting agricultural settings—in Maryland, Nebraska, California, and Washington. Primary crops included corn at all sites, soybeans in Maryland, orchards in California and Washington, and vineyards in Washington. Pesticides and pesticide degradates detected in water samples from all four areas were predominantly from two classes of herbicides—triazines and chloroacetanilides; insecticides and fungicides were not present in the shallow ground water. In most samples, pesticide degradates greatly exceeded the concentrations of parent pesticide. In samples from Nebraska, the parent pesticide atrazine [6‐chloro‐N‐ethyl‐N′‐(1‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine] was about the same concentration as the degradate, but in samples from Maryland and California atrazine concentrations were substantially smaller than its degradate. Simazine [6‐chloro‐N,N′‐diethyl‐1,3,5‐triazine‐2,4‐diamine], the second most detected triazine, was detected in ground water from Maryland, California, and Washington. Metolachlor [2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐N‐(2‐methoxy‐1‐methylethyl)acetamide] rarely was detected without its degradates, and when they were detected in the same sample metolachlor always had smaller concentrations. The Root‐Zone Water‐Quality Model was used to examine the occurrence and fate of metolachlor at the Maryland site. Simulations accurately predicted which metolachlor degradate would be predominant in the unsaturated zone. In analyses of relations among redox indicators and pesticide variance, apparent age, concentrations of dissolved oxygen, and excess nitrogen gas (from denitrification) were important indicators of the presence and concentration of pesticides in these ground water systems.
Sorption of Aromatic Compounds to Clay Mineral and Model Humic Substance–Clay Complex: Effects of Solute Structure and Exchangeable Cation
Authors: Zhang Yingjie , Zhu Dongqiang , Yu Hongxia
Published: May 2008

Clay minerals and humic substance (HS)–clay complexes are widely distributed in soil environments. Improved predictions on the uptake of organic pollutants by soil require a better understanding of fundamental mechanisms that control the relative contribution from organic and inorganic constituents. Five selected aromatic compounds varying in electronic structure, including nonpolar phenanthrene (PHEN), 1,2,4,5‐tetrachlorobenzene (TeCB), polar 1,3‐dinitrobenzene (DNB), 2,6‐dichlorobenzonitrile (dichlobenil [DNL]), and 1‐naphthalenyl methylcarbamate (carbaryl [CBL]), were sorbed separately from aqueous solution to Na+–, K+–, Cs+–, and Ca2+–saturated montmorillonites with and without the presence of dissolved HS at pH about 6. Upon normalizing for hydrophobic effects by solute aqueous solubility, the overall trend of sorptive affinity to HS‐free K+–clay is DNB ≫ DNL, CBL > PHEN, TeCB, indicating preferential adsorption of the polar solutes. With the presence of HS, sorption of PHEN, TeCB, and CBL increases by several times compared with the pure clay, attributed to HS‐facilitated hydrophobic partition (PHEN and TeCB) or H‐bonding (CBL). The enhanced sorption of PHEN by HS is cation dependent, where Cs+ shows the strongest facilitative effect. Coadsorption of HS does not affect sorption of DNB and DNL to clays except that of DNB to Ca2+–clay because cation–dipole interactions between the polar group (NO2 or CN) of solute and weakly hydrated exchangeable cations dominate the overall sorption.
Enzyme‐Based Resource Allocated Decomposition and Landscape Heterogeneity in the Florida Everglades
Authors: Penton C. Ryan , Newman Susan
Published: May 2008

Enzyme catalyzed reactions are generally considered the rate‐limiting step in organic matter degradation and may be significantly influenced by the structure and composition of plant communities. Changes in these rates have the potential to effect long‐term peat accumulation and influence the topography of a wetland ecosystem. To determine habitat influences on enzyme activities, we examined slough and sawgrass plots within enriched and reference phosphorus (P) sites in the Everglades. Assays were performed for the enzymes involved in carbon (C), nitrogen (N), and P cycling and lignin depolymerization. Enzyme activities were normalized and analyzed in terms of a resource allocation strategy. Plant composition was found to significantly alter the allocation of enzymatic resources due to varying substrate complexities. Potential decomposition in the slough was less influenced by lignin than in the sawgrass habitats. Additionally, an index relating hydrolytic and oxidative enzymes was significantly greater in the slough habitats, whereas C/N ratios were significantly lower. These indices suggest more favorable decomposition conditions and thus slower peat accretion within the slough communities, which may contribute to the development of elevation differences within the sawgrass ridge and slough topography of the Everglades.
Comparative Study of Transport Processes of Nitrogen, Phosphorus, and Herbicides to Streams in Five Agricultural Basins, USA
Authors: Domagalski Joseph L. , Ator Scott , Coupe Richard , McCarthy Kathleen , Lampe David , Sandstrom Mark , Baker Nancy
Published: May 2008

Agricultural chemical transport to surface water and the linkage to other hydrological compartments, principally ground water, was investigated at five watersheds in semiarid to humid climatic settings. Chemical transport was affected by storm water runoff, soil drainage, irrigation, and how streams were linked to shallow ground water systems. Irrigation practices and timing of chemical use greatly affected nutrient and pesticide transport in the semiarid basins. Irrigation with imported water tended to increase ground water and chemical transport, whereas the use of locally pumped irrigation water may eliminate connections between streams and ground water, resulting in lower annual loads. Drainage pathways in humid environments are important because the loads may be transported in tile drains, or through varying combinations of ground water discharge, and overland flow. In most cases, overland flow contributed the greatest loads, but a significant portion of the annual load of nitrate and some pesticide degradates can be transported under base‐flow conditions. The highest basin yields for nitrate were measured in a semiarid irrigated system that used imported water and in a stream dominated by tile drainage in a humid environment. Pesticide loads, as a percent of actual use (LAPU), showed the effects of climate and geohydrologic conditions. The LAPU values in the semiarid study basin in Washington were generally low because most of the load was transported in ground water discharge to the stream. When herbicides are applied during the rainy season in a semiarid setting, such as simazine in the California basin, LAPU values are similar to those in the Midwest basins.
Contribution of Hydrolysis in the Abiotic Attenuation of RDX and HMX in Coastal Waters
Authors: Monteil‐Rivera Fanny , Paquet Louise , Giroux Romain , Hawari Jalal
Published: May 2008

Sinking of military ships, dumping of munitions during the two World Wars, and military training have resulted in the undersea deposition of numerous unexploded ordnances (UXOs). Leaching of energetic compounds such as hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine (RDX) and octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX) from these UXOs may cause adverse ecological effects so that the long‐term fate of these chemicals in the sea should be known. The present study assesses the contribution of alkaline hydrolysis into the natural attenuation of RDX and HMX in coastal waters. Alkaline hydrolysis rates were shown to be unaffected by the presence of sodium chloride, the most common component in marine waters. Kinetic parameters (Ea, ln A, k2) quantified for the alkaline hydrolysis of RDX and HMX in deionized water (30–50°C, pH 10–12) agreed relatively well with abiotic degradation rates determined in sterilized natural coastal waters (50 and 60°C, variable salinity) even if the latter were generally slightly faster than the former. Furthermore, similar products (HCHO, NO2−, O2NNHCH2NHCHO) were obtained on alkaline hydrolysis in deionized water and abiotic degradation in coastal waters. These two findings suggested that degradation of nitramines in sterilized natural coastal waters, away from light, was mainly governed by alkaline hydrolysis. Kinetic calculations using the present parameters showed that alkaline hydrolysis of RDX and HMX in marine waters at 10°C would respectively take 112 ± 10 and 2408 ± 217 yr to be completed (99.0%). We concluded that under natural conditions hydrolysis should not contribute significantly to the natural attenuation of HMX in coastal waters whereas it could play an active role in the natural attenuation of RDX.
Rethinking the Contribution of Drained and Undrained Grasslands to Sediment‐Related Water Quality Problems
Authors: Bilotta G. S. , Brazier R. E. , Haygarth P. M. , Macleod C. J. A. , Butler P. , Granger S. , Krueger T. , Freer J. , Quinton J.
Published: May 2008

Grass vegetation has been recommended for use in the prevention and control of soil erosion because of its dense sward characteristics and stabilizing effect on the soil. A general assumption is that grassland environments suffer from minimal soil erosion and therefore present little threat to the water quality of surface waters in terms of sediment and sorbed contaminant pollution. Our data question this assumption, reporting results from one hydrological year of observations on a field‐experiment monitoring overland flow, drain flow, fluxes of suspended solids, total phosphorus (TP), and molybdate‐reactive phosphorus (<0.45 μm) in response to natural rainfall events. During individual rainfall events, 1‐ha grassland lysimeters yield up to 15 kg of suspended solids, with concentrations in runoff waters of up to 400 mg L−1 These concentrations exceed the water quality standards recommended by the European Freshwater Fisheries Directive (25 mg L−1) and the USEPA (80 mg L−1) and are beyond those reported to have caused chronic effects on freshwater aquatic organisms. Furthermore, TP concentrations in runoff waters from these field lysimeters exceeded 800 μg L−1 These concentrations are in excess of those reported to cause eutrophication problems in rivers and lakes and contravene the ecoregional nutrient criteria in all of the USA ecoregions. This paper also examines how subsurface drainage, a common agricultural practice in intensively managed grasslands, influences the hydrology and export of sediment and nutrients from grasslands. This dataset suggests that we need to rethink the conceptual understanding of grasslands as non‐erosive landscapes. Failure to acknowledge this will result in the noncompliance of surface waters to water quality standards.
Bioreduction of ionic mercury from wastewater in a fixed-bed bioreactor with activated carbon
Authors: Głuszcz Paweł , Zakrzewska Katarzyna , Wagner-Doebler Irene , Ledakowicz Stanisław
Published: May 2008

Wide industrial use of mercury led to significant mercury pollution of the environment. It requires development of cleanup technologies which would allow treating large volumes of mercury contaminated water in a cost effective and environmentally friendly way. A novel bio-technology, developed from laboratory to industrial scale in Germany at HZI (former GBF), is based on enzymatic reduction of highly toxic Hg(II) to water-insoluble and relatively non-toxic Hg(0) using live mercury resistant bacteria immobilized on a porous carrier material in a fixed-bed bioreactor. Improvement of the original method was based on the use of activated carbon as a carrier for microorganisms and an adsorbent for mercury. Such integration of the process should increase the technology efficiency. In order to compare different carrier materials, activated carbon and pumice stones were used. The strain Pseudomonas putida was immobilized in bioreactors continuously fed with solutions of HgCl2 enriched with nutrients. Simultaneously, experiments in two more reactors were run in the absence of microorganisms to investigate the influence of nutrients on the adsorption process. In the bioreactor with activated carbon, the outlet mercury concentration was approximately 50 % of that supplied with pumice. It may be concluded that the use of activated carbon in a fixed-bed bioreactor enables improvement of the technology by process integration.
Simultaneous production of citric acid and erythritol from crude glycerol by Yarrowia lipolytica Wratislavia K1
Authors: Rymowicz Waldemar , Rywińska Anita , Gładkowski Witold
Published: May 2008

This study shows a possible microbial process for utilization of crude glycerol generated by the biodiesel industry for citric acid and erythritol production. Simultaneous production of citric acid and erythritol under nitrogen-limited conditions with glycerol as the carbon source was achieved with an acetate negative mutant of Y. lipolytica Wratislavia K1 in fed-batch cultivations. The effect of the initial glycerol concentration (from 30–180 g dm−3) on the citrate and erythritol production was investigated. As a result of the experiments, maximum citric acid production (110 g dm−3) and a very high amount of erythritol (81 g dm−3) were determined after 168 h of fed-batch cultivation with the initial glycerol concentration of 150 g dm−3 and the total glycerol concentration of 250 g dm−3. In addition, the citric acid to isocitric acid ratio of the products from this strain was 35.5:1.
Preparation of α-methyl-γ-butyrolactone: Mechanism of its formation and utilization in 2-methyl-1-tetralone synthesis
Authors: Semak Vladislav , Boháč Andrej , Sališová Marta , Addová Gabriela , Danko Peter
Published: May 2008

α-Methyl-γ-butyrolactone (III) has been prepared directly from γ-butyrolactone (I) in 89 % yield by selective monomethylation conditions: K2CO3/DMC/210°C/7 h. The reaction mechanism was elucidated and described. An intermediate and two byproducts: methyl tetrahydro-3-methyl-2-oxofuran-3-carboxylate (II), 3-(methoxycarbonyl)propyl methyl carbonate (IV) and 3-(methoxycarbonyl)butyl methyl carbonate (V) were identified. The high temperature disproportionation of K2CO3 in the presence of dimethyl carbonate to MeOK was observed. The new selective synthesis of 2-methyl-1-tetralone (VI) from α-methyl-γ-butyrolactone (III) by Friedel-Crafts conditions was performed in 79 % yield.
Prediction of excess molar volumes of binary mixtures of organic compounds from refractive indices
Authors: Radović Ivona , Kijevčanin Mirjana , Gabrijel Marijan , Šerbanović Slobodan , Djordjević Bojan
Published: May 2008

The excess molar volumes of 51 binary mixtures containing diverse groups of organic compounds: alcohols (methanol, ethanol, propan-1-ol, butan-1-ol, pentan-1-ol, hexan-1-ol, and heptan-1-ol), (cyclo-) alkanes (hexane, heptane, octane, nonane, decane, undecane, dodecane, and cyclohexane), esters (diethyl carbonate and ethyl chloroacetate), aromatics (o-xylene, m-xylene, p-xylene, and ethylbenzene), ketones (acetone), and ethers (anisole), were predicted from the refractive index data, using three types of equations coupled with several different mixing rules for refractive index calculations: the Lorentz-Lorenz, Dale-Gladstone, Eykman, Arago-Biot, Newton, and the Oster. These systems were chosen since they belong to different classes of organic species forming molecular interactions and intermolecular forces during mixing resulting in positive or negative, smaller or larger deviations from ideal behaviour. The obtained results were analysed in terms of the applied equation and mixing rule, the nature of compounds of the mixtures and the influence of alkyl chain length of the alkane or alcohol molecule.
In situ and ex situ characterization of a Fe-Cr-Ni alloy in mouthwashes and Hank’s solution
Authors: Cestarolli Dane , Alves Valéria , Silva Luís
Published: May 2008

The aim of the present study was to classify the surface oxide layers formed on a Fe-Cr-Ni alloy according to their corrosion resistance in Hank’s solution and mouthwashes by SEM and electrochemical techniques. The SEM micrographs showed the presence of localized corrosion and the polarization curves showed that the passive layer is less stable in the presence of Hank’s solution than of mouthwashes, as a result of the presence of chloride ions.
Synthesis of 2-methyl-2-propoxypropyl isocyanide and its Cu(I) tetraflouroborate complex
Authors: Al-Ktaifani Mahmoud , Nakawa Adnan , Tabbaa Zouheir , Namou Adel
Published: May 2008

2-Methyl-2-propoxypropyl isocyanide [CNCH2C(OPr)(CH3)2] and its Cu(I) tetrafluoroborate complex [Cu{CNCH2C(OPr)(CH3)2}4]BF4 were prepared in good yields and purities. Both compounds were fully characterized by IR and NMR spectroscopy.
The natural regeneration of salt marsh on formerly reclaimed land
Authors: Garbutt Angus , Wolters Mineke
Published: May 2008

Question: Does the vegetation of restored salt marshes increasingly resemble natural reference communities over time?

Location: The Essex estuaries, southeast England.

Methods: Abandoned reclamations, where coastal defences had been breached in storm events, and current salt marsh recreation schemes were surveyed giving a chronosequence of salt marsh regeneration from 2 to 107 years. The presence, abundance and height of plant species were recorded and comparisons were made with adjacent reference salt marsh communities at equivalent elevations.

Results: Of the 18 paired sites surveyed, 13 regenerated marshes had fewer species than their adjacent reference marsh, three had an equal number and two had more. The plant communities of only two de‐embankment sites matched that of the reference community. 0–50 year old sites and 51–100 year old sites had fewer species per quadrat than the 101+ year sites and the reference salt marshes. There was a weak relationship between differences in species richness for regenerated and reference marshes and the time since sites were first re‐exposed to tidal inundation. Cover values for the invasive and recently evolved Spartina anglica were greater within regenerated than reference marshes.

Conclusions: Salt marsh plants will colonise formerly reclaimed land relatively quickly on resumption of tidal flooding. However, even after 100 years regenerated salt marshes differ in species richness, composition and structure from reference communities.
The Effect of Alloying on the Bandgap Energy of Nanoscaled Semiconductor Alloys
Authors: Zhu Yong Fu , Lang Xing You , Jiang Qing
Published: April 2008

Based on a model for the size‐dependent bandgap energy of low‐dimensional semiconductor compounds, the alloying effect on the bandgap of nanoscale semiconductors is modeled without any adjustable parameter. The model predicts not only a trend of increasing bandgap with decreasing nanocrystal size but also Végard¢s relationship between the bandgap and the alloy composition when the size drops close to twice that of the critical size for the nanocrystals. The model predictions agree with available experimental results for bandgap changes of pseudo‐binary IIB–VIB chalcogenide semiconductor nanocrystals.
Viscosity of moderately concentrated solutions of polymethyl‐methacrylate in methyl‐methacrylate
Authors: Singh Gurpreet J. , Gupta Santosh K.
Published: May 2008

A Haake® viscometer with the NV cup‐and‐bob sensor is used to measure the viscosity, η, of polymethyl methacrylate (PMMA) solutions in methyl methacrylate (MMA) at several polymer concentrations, weight‐average molecular weights, and temperatures, and under nonreacting conditions. Six polymer samples having different average molecular weights are prepared by polymerizing MMA in a 1‐L batch reactor using 2,2′‐azoisobutyronitrile (AIBN) as the initiator. Our earlier experimental data (at moderate concentrations of the polymer) on the viscosity of PMMA solutions in MMA under reacting conditions is also used. Two general correlations are developed between $ {\eta \over \eta_{\rm sol}} $ and CpolyM with the parameters obtained using genetic algorithm. The tuned correlations for viscosity can be used over an extended range of monomer conversions for model‐based state estimation and on‐line optimal control of the bulk polymerization of MMA. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and characterization of poly(methyl methacrylate)‐grafted silica microparticles
Authors: Derouet Daniel , Ha Thuc Chi Nhan
Published: May 2008

A procedure to synthesize poly(methyl methacrylate)‐grafted silica microparticles was developed by using radical photopolymerization of methyl methacrylate (MMA) initiated from N,N‐diethyldithiocarbamate (DEDT) groups previously bound to the silica surface (grafting “from”). The functionalization of silica microparticles with DEDT groups was performed in two steps: introduction of chlorinated functions onto the surface of silica particles, and then nucleophilic substitution of chlorines by DEDT functions via a SN2 mechanism. The study was performed with a Kieselgel® S silica which was initially chlorinated in surface, either by direct chlorination of silanols with thionyl chloride, or by using a condensation reaction between silanols and a chlorofunctional trialkoxysilane reagent, 4‐(chloromethyl)phenyltrimethoxysilane and chloromethyltriethoxysilane, respectively. Three types of DEDT‐functionalized silica microparticles were prepared with a good control of the reactions, and then characterized by solid‐state 13C and 29Si CP/MAS NMR. Their ability to initiate MMA photopolymerization was studied. The kinetics of MMA photopolymerization was followed by HPLC and 1H‐NMR. Whatever the silica used the grafting progresses very slowly. On the other hand, the conversion of MMA in PMMA grafts is depending on the structure of the DEDT‐functionalized Kieselgel® S used. Poly(methyl methacrylate)‐grafted silica microparticles bearing high length grafts ($ \overline {{\rm DP}_n} $ about 100) were synthesized. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Arginine Dynamics in a Membrane‐Bound Cationic Beta‐Hairpin Peptide from Solid‐State NMR
Authors: Tang Ming , Waring Alan J. , Hong Mei
Published: April 2008

The site‐specific motion of Arg residues in a membrane‐bound disulfide‐linked antimicrobial peptide, protegrin‐1 (PG‐1), was investigated by using magic‐angle‐spinning solid‐state NMR spectroscopy to better understand the membrane insertion and lipid interaction of this cationic membrane‐disruptive peptide. The C–H and N–H dipolar couplings and 13C chemical shift anisotropies were measured in the anionic POPE/POPG membrane, and were found to be reduced from the rigid‐limit values by varying extents; this indicates the presence of segmental motion. An Arg residue at the β‐turn region of the peptide showed much weaker spin interactions, which indicates larger amplitudes of motion than an Arg residue in the β‐strand region of the peptide. This is consistent with the exposure of the β turn to the membrane surface and the immersion of the β strand in the hydrophobic middle of the membrane, and supports the previously proposed oligomerization of the peptide into β barrels in the anionic membrane. The 13C T2 and 1H T1ρ relaxation times indicate that the β‐turn backbone undergoes large‐amplitude intermediate‐timescale motion in the fluid phase of the membrane; this causes significant line broadening and loss of spectral intensity. This study illustrates the strong correlation between the dynamics and structure of membrane proteins, and the capability of solid‐state NMR spectroscopy to provide detailed information on site‐specific dynamics in complex membrane‐protein assemblies.
Tucker1 model algorithms for fast solutions to large PARAFAC problems
Authors: Van Benthem Mark H. , Keenan Michael R.
Published: April 2008

We describe a method of performing trilinear analysis on large data sets using a modification of the PARAFAC‐ALS algorithm. Our method iteratively decomposes the data matrix into a core matrix and three loading matrices based on the Tucker1 model. The algorithm is particularly useful for data sets that are too large to upload into a computer's main memory. While the performance advantage in utilizing our algorithm is dependent on the number of data elements and dimensions of the data array, we have seen a significant performance improvement over operating PARAFAC‐ALS on the full data set. In one case of data comprising hyperspectral images from a confocal microscope, our method of analysis was approximately 60 times faster than operating on the full data set, while obtaining essentially equivalent results. Copyright © 2008 by John Wiley & Sons, Ltd.
To What Extent Can Viable Bacteria in Atmospheric Aerosols be Dangerous for Humans?
Authors: Safatov Alexandre S. , Andreeva Irina S. , Belan Boris D. , Buryak Galina A. , Emel'yanova Elena K. , Jaenicke Ruprecht , Panchenko Mikhail V. , Pechurkina Natalya I. , Puchkova Larisa I. , Repin Vladimir E. , Saranina Irina V. , Sergeev Alexander N.
Published: April 2008

Multi‐year monitoring of atmospheric bioaerosol in Southwestern Siberia revealed the presence of a large number of various culturable microorganisms. It is known that viable microorganisms can cause directly or provoke different human diseases. It's very difficult to evaluate the danger represented by each microorganism to man directly. Therefore, a relatively simple method is required for evaluation of potential danger represented to man by the whole assembly of culturable microorganisms in an atmospheric aerosol sample. For bacteria, the method can be based on a number of individual characteristics of each microorganism determined in the course of biochemical and other test required for identification of the detected bacterium, and a number of other tests. It is proposed to classify the measured individual characteristics of bacteria under four groups of indices responsible for: (i) potential pathogenicity for man; (ii) the numbers of bacteria in the sample; (iii) resistance to unfavorable environmental factors; (iv) drug resistance of bacteria. Each of four groups of indices is numerically evaluated by a certain integral index, which quantitatively reflects the contribution of experimentally determined characteristics of bacteria. Expert evaluation of the contribution of each characteristic of microorganisms to the corresponding group of indices is performed. The generalized index of potential danger of culturable bacteria in atmospheric aerosols for human health is presented as the product of four integral indices summarizing the normalized individual integral indices for all bacteria detected in the sample. The work presents the results of measuring the variations of all the above indices for atmospheric air samples collected during one year.
Pubertal maturation modifies the regulation of insulin‐like growth factor‐I receptor signaling by estradiol in the rat prefrontal cortex
Authors: Sanz Amaya , Carrero Paloma , Carrero Paloma , Pernía Olga , Garcia‐Segura Luis M.
Published: April 2008

The transition from adolescence to adulthood is accompanied by substantial plastic modifications in the cerebral cortex, including changes in the growth and retraction of neuronal processes and in the rate of synaptic formation and neuronal loss. Some of these plastic changes are prevented in female rats by prepubertal ovariectomy. The ovarian hormone estradiol modulates neuronal differentiation and survival and these effects are in part mediated by the interaction with insulin‐like growth factor‐I (IGF‐I). In this study, we have explored whether the activation by estradiol of some components of IGF‐I receptor signaling is altered in the prefrontal cortex during puberty. Estradiol administration to rats ovariectomized after puberty resulted, 24 h after the hormonal administration, in a sustained phosphorylation of Akt and glycogen synthase kinase 3β in the prefrontal cortex. However, this hormonal effect was not observed in animals ovariectomized before puberty. These findings suggest that during pubertal maturation there is a programming by ovarian hormones of the future regulatory actions of estradiol on IGF‐I receptor signaling in the prefrontal cortex. The modification in the regulation of IGF‐I receptor signaling by estradiol during pubertal maturation may have implications for the developmental changes occurring in the prefrontal cortex in the transition from adolescence to adulthood. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008.