bluuebunny/crossref_metadata_2025 huggingface dataset:
The innovative moving bed biofilm reactor/solids contact reaeration process for secondary treatment of municipal wastewater
Authors: Rusten Bøjrn , McCoy Mike , Proctor Robert , Siljudalen Jon G.
Published: September 2006

The innovative moving bed biofilm reactor/solids contact reaeration (MBBR/SCR) process has been chosen for a new wastewater treatment plant serving a population of 200 000 at Moa Point, Wellington, New Zealand. Because the MBBR/SCR combination was new, a pilot‐scale demonstration project was made part of the contract. Thorough pilot tests using a wide range of organic loads under both steady and transient‐flow conditions demonstrated that the MBBR/SCR process produced the required effluent quality at loads higher than used in the original design. At 3 days mean cell residence time (MCRT) in the SCR stage, a final effluent with a 5‐day biochemical oxygen demand (BOD5) of less than 10 mg/L was achieved at an organic load on the MBBR of 15 g BOD5/m2·d (5.0 kg BOD5/m3·d). With the same MCRT, a final effluent of less than 15 mg BOD5/L was achieved at an organic load on the MBBR of 20 g BOD5/m2·d (6.7 kg BOD5/m3·d). Dynamic loading tests demonstrated that a good‐quality effluent was produced with a diurnal peak‐hour load on the MBBR of more than 40 g BOD5/m2·d (13.3 kg BOD5/m3·d). The MBBR/SCR process was more compact and significantly cheaper than a conventional trickling filter/solids contact or activated‐sludge process at the Moa Point site.
Production and decomposition of nitrous oxide during biological denitrification
Authors: Spector Marshall
Published: September 2006

Nitrate (NO3) was reduced with methanol (MeOH) over denitrification‐filter sludge in a closed reactor. The initial reaction product was nitrous oxide (N2O). It accumulated to a maximum (N2Omax) and was then rapidly reduced to nitrogen (N2). At the time of maximum accumulation (tmax), 50 to 80% of the nitrate‐nitrogen reduced was in the form of N2O. These results led to a higher estimate of N2O emission from biological denitrification than previously considered. The results also suggest the concept of a multistage anoxic reactor in which nitrate can be reduced to N2 with minimal emission of N2O. The design would provide for retention of N2O in the upstream stages and reduction of N2O downstream.
Chemistry of heavy metal precipitates resulting from reactions with Thio‐Red®
Authors: Henke Kevin R.
Published: September 2006

Thio‐Red® is a commercial product that is widely used to precipitate divalent heavy metal contaminants from water. To gain a better understanding of how Thio‐Red® reacts with dissolved divalent metals, the product was added to laboratory aqueous solutions, each of which contained one of several dissolved copper, lead, mercury, and zinc compounds. In all of the solutions, precipitates rapidly formed after adding Thio‐Red®. X‐ray diffraction analyses of the precipitates detected ordinary metal sulfides rather than metal thiocarbonates. Further investigations identified reactions that may be responsible for the formation of the precipitates.
Virus removal by advanced membrane filtration for wastewater reclamation
Authors: Iranpour Reza
Published: September 2006

Measurements of indigenous and seeded male‐specific (MS2) bacteriophages were made in an effort to gain insight into the response of membrane filtration systems to varying virus concentrations and varying flow rates at the Terminal Island Treatment Plant, operated by the City of Los Angeles Bureau of Sanitation. Bacteriophages were seeded into secondary effluent that had been filtered through a trimedia filter. The seeded effluent was then processed by microfiltration (MF) and reverse osmosis (RO) pilot units for which the Department of Water and Power was evaluating effluent water quality parameters in conjunction with a water reclamation project. The samples were assayed for virus. The seeded tests utilized higher concentrations of MS2 viruses and sampled the process streams with higher time resolution than those used by other researchers in comparable experiments. As expected from the physics of RO process, the RO unit reduced the virus concentration below the threshold of detection, but the MF membranes consistently reduced virus concentrations by less than one log unit (order of magnitude). This MF performance differs from most results of similar tests carried out elsewhere, but it was consistently observed, despite substantial variability in the virus removal factor, as revealed by the high time resolution of the measurements. Budgetary limits prevented extending this research to clarify the indications in the data that removal efficiency may be affected by the MF unit's backwash cycle, or the membrane flux, but if these results can be verified, they may provide valuable insight for improved membrane technology and planning for large‐scale membrane‐based water reclamation.
Cocurrent biological nitrification and denitrification in wastewater treatment
Authors: Spector Marshall
Published: September 2006

Repetitive conditioning of recycle activated sludge (RAS) under strict anaerobic conditions gradually changes the products of ammonia oxidation from nitrite and nitrate to nitrous oxide (N2O) and nitrogen (N2). Nitrite inhibits oxygen respiration of anaerobically conditioned sludge; biochemical oxygen demand (BOD) is then oxidized by nitrite, which is reduced to N2O and N2. When anaerobic RAS conditioning is initially imposed on a nitrifying system, Nitrobacter species continue to oxidize nitrite to nitrate and thus reduce the nitrite available to oxidize BOD. However, Nitrobacter in the mixed liquor gradually tend to wash out because the sole source of Nitrobacter energy, the oxidation of nitrite to nitrate, is diminished to the extent that nitrite is reduced. Incorporation of an RAS conditioning zone to the activated‐sludge process results in evolution of a nonfilamentous biomass, which affects both cocurrent biological nitrification and denitrification (CBND) and biological phosphorus removal (BPR). The initial feed zone may be either aerobic or anaerobic. A final anoxic denitrification zone is desirable for removal of residual nitrite plus nitrate (NOx) from aeration effluent. Nitrous oxide, the main reaction product of CBND, promotes both global warming and destruction of the stratospheric ozone layer.
Evaluation of methods to detect and control nitrification inhibition with specific application to incinerator flue‐gas scrubber water
Authors: Daigger Glen T. , Sadick Thomas E.
Published: September 2006

Two procedures for determining the maximum specific growth rate of nitrifying bacteria in the presence of inhibitors were evaluated. One procedure uses a population of nitrifying bacteria and a short‐term (6‐hour) batch assay to determine the impact of the test wastewater on the maximum specific growth rate of the nitrifiers. The difference in the specific nitrification rate for the subject population between a control and the test wastewater quantifies the effect of the constituents in the test wastewater on the nitrifier maximum specific growth rate. The second procedure uses batch fill‐and‐draw bioreactors operated under steady‐state conditions to determine the minimum mean cell residence time for growth of the nitrifiers. The need to assess nitrification inhibition at two large municipal wastewater treatment plants provided the opportunity to evaluate these two procedures. Incineration of biosolids is practiced at both of these plants, and it was shown that in‐plant recycle of the multiple‐hearth flue‐gas scrubber water can be inhibitory to nitrification. Results from extensive testing indicated that hydrocyanic acid (HCN), present in the scrubber water, is the probable inhibitor. Consistent results were obtained at both plants. They indicated that HCN concentrations on the order of 0.1 to 0.2 mg/L resulted in a reduction in the nitrifier maximum specific growth rate of approximately 50%. Treatment methods were evaluated at each plant and implemented. At one plant, aerobic biological treatment of the incinerator sidestream is being practiced. At the other facility, cyanide is thermally destroyed in afterburners before contact with the wet scrubbing system.
Evaluation of commercial ultrafiltration systems for treating automotive oily wastewater
Authors: Kim B.R. , Kalis E.M. , Florkey D.L. , Swatsenbarg S.L. , Luciw L. , Bailey C.H. , Gaines W.A. , Phillips J.H. , Kosokowsky G.B.
Published: September 2006

Currently at Ford Motor Company, oily wastewater is batch treated by chemical deemulsification whose performance depends on determining optimum chemical dosages and is occasionally inconsistent because of influent fluctuations. Therefore, a pilot study was conducted at the Ford Romeo Engine Plant, Romeo, Michigan, to study treatment of raw oily wastewater and skim oil (from chemical deemulsification) using commercially available ultrafiltration (UF) systems as an alternative to chemical deemulsification. The study found that most UF membranes performed consistently and reliably, producing average permeate oil and grease (O&G) concentrations of less than 100 mg/L, a typical discharge limit for an automotive plant. In addition, tubular membranes typically outperformed spiral‐wound membranes in permeate flux and washing frequency. While all UF systems performed consistently well for removing O&G, the treated effluent still had a chemical oxygen demand (COD) of 100 to 2 000 mg/L, which is comparable to that found in typical chemically treated wastewater. This indicates that many dissolved organics are not removed by either chemical or UF treatment. Metals (such as copper and zinc) were found to be effectively removed by UF when the pH was greater than 8. Most membranes used as a second stage produced retentate with O&G of more than 40%. All attempts at UF skim oil treatment were unsuccessful because of high oil viscosity, which made pumping it through a membrane system almost impossible. Chemical reactions during the chemical deemulsification process might have been responsible for the high viscosity.
Solids separation parameters for secondary clarifiers
Authors: Hasselblad Serena , Xu Shulan
Published: September 2006

Efficient separation of solids and supernatant is crucial in an activated‐sludge system because the performance of the system depends on the return of active biological solids to the biological reactor. For optimization and planning of the process, dynamic models describing the settling process are available. To use these models for simulations, parameters that characterize biomass settling must be known. The one‐dimensional model used in this work requires characteristic settling parameters from repeatedly performed batch tests. However, the model, together with its characteristic parameters, applies better to deep circular clarifiers than to rectangular ones. This work describes a new method to find the alternative settling parameters VA and nA, from dynamic measurements in a full‐scale rectangular clarifier, to be used for simulations of the same clarifier. Results from simulations of the movement of sludge blanket height in different clarifiers using the parameters VA and nA agreed well with full‐scale performance.
Evaluation of methods for estimating stormwater pollutant loads
Authors: Charbeneau Randall J. , Barrett Michael E.
Published: September 2006

This paper investigates a number of methods that can be used to generate constituent concentrations for use in stormwater modeling. These include the use of event mean concentrations (EMCs) and pollutant buildup and washoff formulations. Suspended solids data collected in the Austin, Texas, area from single‐land‐use watersheds were used to evaluate the usefulness of these methods. Use of a single EMC for all urban land uses was shown to provide a reasonable estimate of solids loads. This suggests that increases in total suspended solids loads resulting from development will be primarily a function of the increase in runoff volume, which in turn may be related to increased impervious cover. Water quality data did not indicate a strong correlation between initial pollutant load on the watershed and length of the antecedent dry period; however, the concentration of suspended solids in stormwater runoff does follow a simple washoff model.
Gasification of char from wastewater solids pyrolysis
Authors: Lee Kun M.
Published: September 2006

Batch experiments were carried out to evaluate the effects of reaction temperature, reaction time, and char‐to‐steam ratio on the gasification of char from wastewater solids pyrolysis. The batch experiments revealed that more than 97% volatile solids reduction efficiency can be attained by maintaining reaction temperature at 950 to 1 000°C, reaction time at 30 minutes, and char‐to‐steam ratio at 1:10. The increase in reaction temperature resulted in a reduction in hydrogen‐to‐carbon monoxide (H2/CO) and carbon dioxide‐to‐carbon monoxide (CO2/CO) ratios, suggesting that the carbon–steam reaction reaches equilibrium at 800°C and higher. However, the Boudourd reaction continued to progress toward more product formation with the increase in temperature.
Increasing substrate for polyphosphate‐accumulating bacteria in municipal wastewater through hydrolysis and fermentation of sludge in primary clarifiers
Authors: Christensson Magnus , Lie Ewa , Jönsson Karin , Johansson Per , Welander Thomas
Published: September 2006

The possibility of improving enhanced biological phosphorus removal (EBPR) by increasing the level of substrate for biological polyphosphate‐accumulating bacteria in influent wastewater, achieved through enhanced hydrolysis and fermentation of primary sludge in the primary clarifiers, was studied at a full‐scale University of Cape Town plant for more than 1 year. The sludge level in the clarifiers was increased to create anaerobic conditions and to increase the solids retention time in the clarifiers. Recirculation of sludge from the bottom to the top of the clarifiers was begun to wash out the fermentation products formed in the sludge phase into the water leaving the clarifiers. The performance of the EBPR plant improved considerably after enhanced hydrolysis and fermentation were established in the primary clarifier. Daily analyses at the treatment plant and laboratory‐scale fermentation experiments on sludge from the clarifiers showed that the soluble chemical oxygen demand (COD) in the wastewater increased by up to 10 mg CODIL. Measurements of volatile fatty acid potential (VFA‐potential) yielded an increase of 5 to 10 mg/L VFA‐COD. Long‐term fermentations in the laboratory showed that another 15 to 20 mg/L of VFA‐COD could be derived from the sludge, should the hydrolysis and fermentation be prolonged and optimized; if applied to a full‐scale wastewater treatment plant, this process would require the use of a separate reactor.
Anaerobic sequencing batch reactor treatment of dilute wastewater at psychrophilic temperatures
Authors: Dague Richard R. , Banik Gouranga C. , Ellis Timothy G.
Published: September 2006

Anaerobic treatment of dilute wastewater was studied using three laboratory‐scale anaerobic sequencing batch reactors (ASBRs), each with an active volume of 6 L. The reactors were fed a synthetic substrate made from nonfat dry milk supplemented with nutrients and trace metals. The chemical oxygen demand (COD) and 5‐day biochemical oxygen demand (BOD5) of the feed were 600 mg/L and 285 mg/L, respectively. Steady‐state performance data were collected over a time period of 2 years at reactor temperatures of 5, 7.5, 10, 12.5, 15, 17.5, 20, and 25°C. Hydraulic retention times (HRTs) were maintained at 24, 16, 12, 8, and 6 hours. Steady‐state process kinetics and removal efficiencies were evaluated for the various conditions. Results showed that the ASBR process was capable of achieving more than 90% soluble COD (SCOD) and BOD5, removal at temperatures of 20°C and 25°C at all HRTs. At a temperature of 5°C and a 6‐hour HRT, SCOD and BOD5, removals were 62% and 75%, respectively. At intermediate temperatures ranging from 5 to 25°C and HRTs between 24 and 6 hours, removal of soluble organic matter ranged from 62 to 90% for COD and from 75 to 90% for BOD5. In all cases, solids retention times were high enough to maintain good performance. Substrate removal rates and half‐saturation coefficients were also determined at all temperatures. The temperature correction coefficient was determined to be 1.08 in the temperature range of 7.5 to 25°C. It is concluded that the ASBR has unique characteristics that enable efficient removal of organics during treatment of dilute wastewaters at low temperatures.
Dual role of activated carbon process for water reuse
Authors: Kuo Jih‐Fen , Stahl James F. , Chen Ching‐Lin , Bohlier Paul V.
Published: September 2006

Four granular activated carbon (GAC) filters went into service in 1977 at the County Sanitation Districts of Los Angeles County's Pomona Water Reclamation Plant to treat 0.44 m3/s (10 mgd) of wastewater for reuse. This article provides long‐term operational information for similar water reuse applications. The GAC filters successfully served dual roles as tertiary filters and adsorbers of organics. After 10 regenerations with an average 10% makeup of virgin carbon per regeneration, the iodine number dropped from 1 000 mg/g to a leveled‐off value of 600 mg/g; the molasses number increased from 170 to 250; apparent density decreased slightly; and mean particle diameter decreased from 1.65 mm to 1.2 mm. The ash content increased steadily from the initial 6.5% to more than 15% after 15 regenerations. After 20 regenerations, the GAC filters still exerted a total organic carbon removal from more than 80% initially to a level of 20%. The removal of true color by the regenerated carbon decreased from 90% initially to 30%. With the provisions of an after‐burner and a wet Venturi scrubber, the air emissions from the carbon regeneration facility were effectively controlled. The energy and labor costs become the dominant operation and maintenance costs as the regeneration frequency increases.
Two‐stage biotransformation of 2,4,6‐trinitrotoluene under nitrogen‐rich and nitrogen‐limiting conditions
Authors: VanderLoop Sarah L. , Suidan Makram T. , Moteleb Moustafa A. , Maloney Stephen W.
Published: September 2006

An anaerobic fluidized‐bed granular activated carbon bioreactor in series with an activated‐sludge reactor was used to treat a wastewater containing 100 mg/L 2,4,6‐trinitrotoluene (TNT). The performance of the system was evaluated under both nitrogen‐rich and nitrogen‐limiting conditions. When 18 mg/L ammonia‐nitrogen was supplied to the system, the mixed anaerobic culture completely transformed the TNT to unknown products. Effluent ammonia‐nitrogen routinely was more than 21 mg/L, and nitrite was also detected in the anaerobic reactor effluent, possibly indicating two distinct methods of nitrogen removal from the ring. The effluent from this reactor was treated further in an activated‐sludge system. A significant fraction of the TNT transformation products was oxidized in the aerobic stage, resulting in recovery of 82% of influent TNT‐nitrogen and at least 73% TNT‐carbon mineralization in the system. When the anaerobic reactor received only TNT as a nitrogen source, anaerobic reactor effluent ammonia levels remained above 3 mg/L, but nitrite was not detected. The resulting TNT biotransformation products could not be completely identified, but they did persist in the final effluent. The inability of the activated sludge to effect further transformation of some of these compounds was quantified as a substantial reduction in inorganic nitrogen recovery. Only 55% of influent TNT‐nitrogen was recovered in the system during the nitrogen‐limited operation.
Ultraviolet disinfection of marginal effluents: determining ultraviolet absorbance and subsequent estimation of ultraviolet intensity
Authors: Linden Karl G. , Darby Jeannie L.
Published: September 2006

The ultraviolet (UV) absorbance characteristics of effluents with a wide range of water quality were measured using direct and integrating sphere spectroscopy. The point source summation (PSS) method was used to estimate the effect of three UV absorbance measurement techniques (filtered direct, unfiltered direct, and unfiltered integrating sphere) on estimation of UV intensity in a UV reactor. Intensity values estimated from the PSS model were compared with direct intensity measurements made with a chemical actinometer. Use of the integrating sphere method for measuring the UV absorbance of the bulk wastewater was validated experimentally with UV absorbance coefficients derived from chemical actinometry. Absorbance coefficient values derived from direct spectroscopy were significantly different from the actinometrically derived absorbance coefficients. Particulates in wastewater both absorbed and scattered UV light, decreasing the overall available UV radiation for disinfection. As compared to the integrating sphere method, use of either filtered or unfiltered direct absorbance to determine the UV intensity with the PSS model provided an overestimate or underestimate of UV intensity, respectively. No significant differences were observed between the chemical actinometry and point source summation methods of estimating UV intensity after accounting for experimental differences.
Staging of anaerobic processes for reduction of chronically high concentrations of propionic acid
Authors: Duran Metin , Speece R.E.
Published: September 2006

The objective of this research was the reduction of chronic elevated propionate from a bench‐scale, anaerobic completely stirred tank reactor (CSTR) without biomass recycle treating synthetic molasses wastewater. Pretreatment and posttreatment alternatives were specifically examined using a high–food‐to‐microorganism (F/M) contact chamber as the preliminary operation unit in one case and an upflow anaerobic sludge blanket (UASB) reactor as the posttreatment unit in the second case. The high‐F/M contact reactor unit, operated before the main reactor, was a two‐stage (not a two‐phase) configuration. After the feed contacted biomass that was recycled from the main reactor for a period of 1 day in a high‐F/M contact reactor, the entire contents of the high‐F/M contact reactor were transferred back to the main reactor. This brief contact operation resulted in a dramatic decrease in propionate concentrations in the effluent of the main reactor, which had been producing consistently high concentrations for approximately 4 months. After incorporation of the high‐F/M contact reactor in the preliminary treatment step, the propionic acid concentration dropped significantly, from 1 050 mg/L to 300 mg/L. The results of this investigation showed that the contact time and F/M ratio in the high‐F/M reactor were critical parameters in determining the efficacy of the two‐stage configuration. In the second part of the study, the effluent from the main reactor (not incorporating a precontact reactor) was subjected to posttreatment by a UASB reactor filled with granular biomass. After an acclimation period of approximately 1 month, which provided a hydraulic retention time of 1 day in the UASB unit, the concentration of approximately 1 050 mg/L of propionic acid in the main reactor effluent fell to less than the quantification limit of 20 mg/L in the effluent of the UASB posttreatment unit. The overall success of both portions of the study seem to demonstrate the inappropriateness of using a one‐stage CSTR process configuration for anaerobic metabolism of propionate derived from carbohydrate wastewaters.
The Autopsy in Pediatrics and Pediatric Oncology: A Single-Institution Experience
Authors: Buckner Tyler , Blatt Julie , Smith Scott Victor
Published: September 2006

Autopsy rates and clinicopathologic correlations for pediatric autopsies and the subgroup of pediatric oncology autopsies in a large teaching hospital were studied to evaluate the utility of autopsy in these populations. Autopsy records of the University of North Carolina hospitals from 1982 to 2001 were reviewed for all patients less than 18 years of age. Autopsies performed during 1982 to 1991 (decade 1) were compared to those from 1992 to 2001 (decade 2) with respect to absolute numbers of autopsy and rates of unexpected postmortem diagnoses. Postmortem diagnostic discrepancies were subclassified into major and minor categories. The mean number of autopsies per year for decade 1 was 110 ± 24.5, compared with 77.5 ± 40.9 for decade 2 (P < 0.001), a change largely due to a decline in fetal/perinatal (patients < 7 days of age) autopsies. Of 533 pediatric autopsies, 43 were in patients with a primary diagnosis of a neoplasia. At least one antemortem misdiagnosis and/or clinically occult process was identified in 20.5% of all pediatric autopsy cases, and in 25.6% of pediatric oncology cases. These rates did not change significantly over time. In 10 of 43 pediatric oncology cases (23.3%), autopsies provided diagnostic information that was previously unknown to the clinicians. Three of these patients died shortly after presentation. Although autopsy rates for fetal/perinatal cases have declined, those for nonperinatal and pediatric oncology patients remain stable. Autopsy continues to provide diagnostic information that is unknown during the antemortem period, and remains a valuable tool for pediatricians and pediatric oncologists.
Conjunctival Splendore-Hoeppli Phenomenon in a 3-Year-Old Child
Authors: Orhan Diclehan , Kiratli Hayyam , Kocabeyoğlu Sibel
Published: September 2006

A case of benign granulomas of the conjunctiva in a 3-year-old girl is reported. Histologic features of the excised conjunctival lesions were consistent with Splendore-Hoeppli phenomenon. This phenomenon is thought to be a granulomatous reaction to an antigen-antibody precipitate related to parasites or fungi. No causative agent is identified in our patient. Immunohistochemical analysis showed no immunoreactivity for immunoglobulin G (IgG), IgM, IgA, or the C3 component of the complement. We propose that the presence of small amelanotic nodular conjunctival tumors should arouse suspicion related to the Splendore-Hoeppli phenomenon even in early childhood.
Synthesis and evaluation of novel ferrocene‐substituted triadimenol analogues
Authors: Fang Jianxin , Jin Zhong , Hu Yan , Tao Weifeng , Shao Ling
Published: September 2006

In search of potent 1H‐1,2,4‐triazole derivatives with improving antifungal activity, a class of novel ferrocene–triadimenol analogues was synthesized and their biological potential evaluated. Screening data revealed that these new derivatives did not have the antifungal activities of parent compounds, but showed unexpectedly promising plant growth regulatory activity. Copyright © 2006 John Wiley & Sons, Ltd.
Cover Picture: A Myoglobin Functional Model Composed of a Ferrous Porphyrin and a Cyclodextrin Dimer with an Imidazole Linker (Chem. Asian J. 3/2006)
Authors: Kano Koji , Kitagishi Hiroaki , Mabuchi Takahiro , Kodera Masahito , Hirota Shun
Published: September 2006

Science imitates life in a 1:1 inclusion complex (FeIIPorImCD) of 5,10,15,20‐tetrakis(4‐sulfonatophenyl)porphinatoiron(II) (FeIIPor) and an O‐methylated β‐cyclodextrin (ImCD) dimer with an imidazole linker. This complex was found to mimic myoglobin and bind dioxygen and carbon monoxide in aqueous solution. The cover picture shows the image of O2 bound to FeIIPorImCD (the original structure was obtained by MM2 calculations). FeIIPorImCD shows a higher affinity for dioxygen than hemoCD, an analogue with a pyridine axial ligand, but poorer selectivity for carbon monoxide. For more information, see the Full Paper “A Myoglobin Functional Model Composed of a Ferrous Porphyrin and a Cyclodextrin Dimer with an Imidazole Linker” by K. Kano and co‐workers on page 358 ff.
Ultrasonographically guided surgical approach to liver tumours involving the hepatic veins close to the caval confluence
Authors: Torzilli G , Montorsi M , Del Fabbro D , Palmisano A , Donadon M , Makuuchi M
Published: September 2006

Background

Intraoperative ultrasonography (IOUS) may allow a more conservative procedure in patients with liver tumours involving a hepatic vein at the caval confluence. The aim of this study was to determine whether IOUS and colour Doppler IOUS might reduce the rate of major hepatectomy and vascular reconstruction in patients with such tumours.

Methods

Of 133 consecutive patients with a liver tumour who underwent hepatectomy, 22 had involvement of a hepatic vein at the caval confluence. The surgical strategy employed was determined by IOUS findings of the relationship between the tumour and hepatic vein, the presence of accessory veins, and portal flow as measured by colour Doppler IOUS following clamping of the hepatic vein to be resected. Mortality, morbidity, major resection, hepatic vein reconstruction and local recurrence rates were evaluated.

Results

There were no hospital deaths and only one patient suffered major morbidity. Although hepatic vein resection was performed in 15 patients, only two underwent major hepatectomy and none had vascular reconstruction. No patients had tumour recurrence at a mean follow-up of 23 months.

Conclusion

IOUS allowed sparing of the liver parenchyma without tumour recurrence in most patients with a tumour involving a hepatic vein at the caval confluence, avoiding more extensive hepatectomy or vascular reconstruction.
Randomized clinical trial of local gentamicin–collagen treatment in advancement flap repair for anal fistula
Authors: Gustafsson U-M , Graf W
Published: September 2006

Background

Endoanal advancement flap repair is widely used in sphincter-preserving surgery for anal fistula, but the high recurrence rate is a major problem. A possible cause of non-healing is local infection of the flap. The aim of this study was to evaluate whether local antibiotic treatment with gentamicin–collagen improves healing after endoanal advancement flap repair for anal fistula.

Methods

Eighty-three patients (52 men and 31 women; mean age 47 (range 17–71) years) who had endoanal advancement flap repair for anal fistula between September 1998 and January 2004 were randomized to surgery with (42 patients) or without (41 patients) application of gentamicin–collagen beneath the flap. Patients were evaluated at 1–3 and 12 months after surgery for healing and/or recurrence.

Results

The overall healing rate with no recurrence at 1 year after surgery was 57 per cent (47 of 83). Twenty-six of 42 patients randomized to gentamicin–collagen healed primarily compared with 21 of 41 patients randomized to surgery only. There were no overall differences in healing rate according to sex, previous fistula surgery, complexity of fistula, smoking habit or body mass index.

Conclusion

Endoanal advancement flap repair for anal fistula has a fairly high primary recurrence rate. Healing was not significantly improved by local application of gentamicin–collagen.
Randomized clinical trial of the effects on anal function of Milligan–MorganversusFerguson haemorrhoidectomy
Authors: Jóhannsson H Ö , Påhlman L , Graf W
Published: September 2006

Background

Studies of haemorrhoidectomy usually report postoperative pain, healing and complications, but rarely consider anal function in the longer term. The primary aim of this randomized trial was to compare long-term changes in anal function after open (Milligan–Morgan) and closed (Ferguson) haemorrhoidectomy.

Methods

A total of 225 patients were included in the trial, 115 in the open group and 110 in the closed group. Continence changes were recorded by means of validated questions and an incontinence score. Pain was self-reported using a visual analogue scale.

Results

Postoperative pain and complications did not differ between the groups. Time to recovery was 17 days in the Milligan-Morgan group and 15 days in the Ferguson group. After 1 month the wounds were healed in 57·0 per cent of patients in the open group and 70·6 per cent of those in the closed group (P = 0·058). At 1 year, 78·9 per cent of the Milligan–Morgan group and 85·3 per cent of the Ferguson group reported no continence disturbance (P = 0·072). The incontinence score was improved at 1 year in the closed group (P = 0·015), but was unchanged in the open group (P = 0·645). Patients who had the Ferguson procedure were more satisfied with the outcome of surgery (P = 0·047).

Conclusion

Closed Ferguson haemorrhoidectomy was superior to the open Milligan–Morgan procedure with respect to long-term anal continence and patient satisfaction.
A 10-year review of surgery for desmoid disease associated with familial adenomatous polyposis
Authors: Latchford A R , Sturt N J H , Neale K , Rogers P A , Phillips R K S
Published: September 2006

Background

Desmoid tumours affect 10–25 per cent of patients with familial adenomatous polyposis and represent a major cause of morbidity and mortality. Surgery for intra-abdominal desmoids has traditionally been used as a last resort or to manage obstructive complications. The aim was to review 10 years of desmoid surgery in patients with familial adenomatous polyposis from a single centre.

Methods

Patients who had surgery for desmoid disease between 1994 and 2004 were identified from the Polyposis Registry database and their hospital notes reviewed.

Results

Twenty patients had surgery to remove 32 desmoid tumours (16 intra-abdominal, 12 abdominal wall, four extra-abdominal). Complete clearance was achieved in 19 tumours and, of these, clinically significant recurrence occurred in eight. There was no difference in recurrence rates for site or sex. There was no operative mortality. Intra-abdominal desmoid resection was associated with a mean resection of 45·55 (range 10–200) cm of small bowel. One patient required long-term parenteral feeding. Median follow-up was 5 (range 0·6–10) years. During this period, one patient died (metastatic duodenal cancer); there was no mortality from desmoid disease.

Conclusion

Surgery for intra-abdominal desmoids in selected patients is less hazardous than previously reported. Surgery for abdominal wall and extra-abdominal tumours is safe. However, disease recurrence remains a major problem.
Increased angiogenic response but deficient arteriolization and abnormal microvessel ultrastructure in critical leg ischaemia
Authors: Ho T K , Rajkumar V , Black C M , Abraham D J , Baker D M
Published: September 2006

Background

Ischaemia is known to induce angiogenesis, but the effects of critical leg ischaemia (CLI) on angiogenesis remain unclear. The aim of this study was to examine the physiological angiogenic response in CLI by investigating the extent of neovascularization, characterizing microvessel subtypes and determining the microvessel ultrastructure.

Methods

Gastrocnemius muscles were biopsied from 12 patients with CLI and 12 without leg ischaemia. Microvessels were evaluated immunohistochemically using three endothelial markers (anti-CD31, anti-CD34 and PAL-E) and anti-α smooth muscle actin (SMA) as a mural cell marker to label arterioles. Ki67 was used to demonstrate active cell proliferation. Further microvessel ultrastructural characteristics were determined by transmission electron microscopy.

Results

The CLI group had significantly higher microvessel density and microvessel : muscle fibre ratio for all endothelial subtypes examined (P < 0·001). PAL-E staining demonstrated the highest increase: 4·7 times higher in CLI muscle. There was no significant difference in αSMA-positive microvessel density (P = 0·118) or microvessel : muscle fibre ratio (P = 0·214). Ki67 staining showed no active cell proliferation. Transmission electron microscopy showed CLI microvessels had abnormal morphology, mainly a thick basement membrane.

Conclusion

A physiological angiogenic response was found in CLI, but the microvessels had an abnormal ultrastructure. A lack of active cell proliferation suggests that the angiogenic response may have been exhausted.
Relationships between personal values and reported behavior on ethical scenarios for law students
Authors: Palermo Josephine , Evans Adrian
Published: September 2006

Lawyers' values might be considered to play some role in the decisions that are made in everyday legal practice. This study aimed to explore the effects of personal value hierarchies on ethical decision making within the context of several ethical dilemmas. A questionnaire was administered utilizing hypothetical situations presented in 11 ethical scenarios and including the Rokeach Value Survey. Logistic regression results suggested that different personal values were significant predictors of reported behavioral choices on respective ethical scenarios. However, the most important values associated with behavior consistent with ethical conduct in scenarios were ‘honesty’ and ‘equality’. The implications of results are discussed in the contexts of ethics education in a tertiary educational environment and in relation to regulation for the professions. Copyright © 2006 John Wiley & Sons, Ltd.
The relation of psychopathy to concurrent aggression and antisocial behavior in high‐risk adolescent girls and boys
Authors: Penney Stephanie R. , Moretti Marlene M.
Published: September 2006

The present study examined the concurrent relationship between psychopathy characteristics as measured by the PCL:YV and aggressive and antisocial behavior in a sample of 142 high‐risk adolescent girls and boys. The unique relationship between each of three PCL:YV factors (Arrogant and Deceitful Interpersonal Style, Deficient Affective Experience, and Impulsive and Irresponsible Behavioral Style) and outcomes was evaluated to determine which aspects of psychopathy are most crucially linked to aggressive and antisocial behavior in adolescents. Dependent measures were expanded to include both relational and physical forms of aggression to better capture meaningful outcomes for girls and boys. Regression analyses showed that the relationships between psychopathic features and outcomes were equivalent for boys and girls, and that deficits in affect were most consistently associated with aggression. These findings are concordant with the well established finding in developmental research showing that deficits in empathy and affect regulation are associated with aggression. Copyright © 2006 John Wiley & Sons, Ltd.
Diverting multi‐problem youth from juvenile justice: investigating the importance of community influence on placement and recidivism
Authors: Hamilton Zachary K. , Sullivan Christopher J. , Veysey Bonita M. , Grillo Michele
Published: September 2006

In the U.S., diversion has increasingly become one of the most utilized alternatives to detention of delinquent youth. Programs providing diversion can vary greatly. Variations in program design make it difficult to evaluate the effectiveness of program outcomes. Utilizing hierarchical linear modeling, this study examines variations in outcome for ten program sites of the New York State MH/JJ Diversion Project. Program and youth predictors were evaluated on two outcomes: out‐of‐ community placement and recidivism. At the individual level, significant mental health and substance abuse problems, age, prior placements, and use of wraparound funds were predictive of youth placements, while significant substance abuse problems were predictive of recidivism. Program variations were found to have a significant impact on youth outcomes. Specifically, sites providing direct (or “in house”) care had significantly reduced rates of placement. Study results and implications for future research are discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Impact of Epimerization Domains on the Intermodular Transfer of Enzyme‐Bound Intermediates in Nonribosomal Peptide Synthesis
Authors: Stein Daniel B. , Linne Uwe , Hahn Martin , Marahiel Mohamed A.
Published: September 2006

Assembly of bioactive natural compounds through the action of nonribosomal peptide synthetases (NRPSs) relies on the specific interplay of modules and domains along these multiple mega‐enzymes. As the C termini of several bacterial NRPSs often harbor epimerization (E) domains that generate D‐amino acids, these seem to facilitate the ordered intermolecular enzymatic interaction and the directed transfer of intermediates. To elucidate this bifunctional role, E domains in recombinant bimodular proteins derived from the tyrocidine synthetase B were investigated. By utilizing sequent tryptic proteolysis and HPLC Fourier transform ion cyclotron resonance mass spectrometry (FTICR‐MS), we could directly interrogate and determine the formation of intermediates attached to the TycB3‐PCP domain of wild‐type TycB2–3 and to the E domain exchange enzyme TycB2–3‐AT⋅CAT/EtycA. In addition, the two proteins and a version of TycB2–3 fused to the communication‐mediating (COM) domain of TycA were applied in product formation assays with TycB1 to corroborate E domain impact on intermodular NRPS interaction. Significant functional differences between the C‐terminal aminoacyl‐ and peptidyl‐E domains were observed in terms of in trans interaction and misinitiation. E domains originating from elongation modules (peptidyl‐E domains) seem to be optimized for regulation of the progression of peptide bond formation, epimerization, and intermediate transfer to the downstream module, whereas E domains of initiation modules (aminoacyl‐E domains) impair upstream condensation and cause misinitiation. The selection of E domains is therefore decisive for successful application in biocombinatorial engineering of nonribosomal peptides.
A Model for Cell‐Surface‐Exposed Carbohydrate Moieties Suitable for Structural Studies by NMR Spectroscopy
Authors: Mares Jiri , Müller Jan U. , Skirgailiene Audrone , Neumoin Alexey , Bewley Carole A. , Schmidt Richard R. , Zerbe Oliver
Published: September 2006

In the present study a synthetic glycolipid system is presented that can be readily incorporated into phospholipid micelles and that allows the study of cell‐surface‐exposed carbohydrate units by high‐resolution NMR techniques. Here, we present an efficient route for the synthesis of glycolipid compounds that contain mannose, mannobiose, or mannotriose coupled either directly to an alkyl chain or through a poly(ethylene glycol) linker. Furthermore, we have validated our model system by measuring the binding of cyanovirin N (CV‐N), a cyanobacterial protein that binds with nanomolar affinity to the terminal arms of high‐mannose structures of the HIV surface‐envelope glycoprotein gp120, to glycolipids the carbohydrate portions of which comprise the corresponding high‐mannose moieties. From the results of chemical‐shift mapping with uniformly 15N‐labelled CV‐N, we conclude that binding to the protein occurs at sites similar to those involved in binding the nonconjugated carbohydrates. We characterized the insertion of the glycolipids into dodecylphosphocholine (DPC) micelles by measuring translational diffusion, and we observed that the diffusion constants of the glycolipids were very similar to those of the DPC micelles themselves, but significantly deviated from those of the free glycolipids. We also present experimental proof that the glycolipids remain inserted in the micelles while binding to CV‐N. Finally, by addition of a ligand that had a higher affinity to CV‐N but which was not attached did not couple to a lipid anchor, CV‐N could be released from the glycolipid and, hence, from the micelle‐associated state.
A Hybrid Metal Oxide Supercapacitor in Aqueous KOH Electrolyte†
Authors: Wang Xiao‐Feng , You Zheng , Ruan Dian‐Bo
Published: September 2006

A novel type of composite electrode based on sheet like cobalt oxide particles has been used in supercapacitors. Cobalt oxide cathodically deposited from Co(NO3)2 solution with carbon nanotubes as matrix exhibited large pseudo‐capacitance of 322 F·g−1 in 6 mol·L−1 KOH. A sol‐gel process for the preparation of ultrafine RuO2 particles was developed to design electrodes with large surface area. The composite electrodes were developed by the deposition of RuO2 on the surface of carbon nanotubes. A specific capacitance of 785 F·g−1 can be achieved with the 20% carbon nanotubes loaded. To characterize the metal oxide nanocomposite electrode, a cyclic voltammetry and AC impedance test are executed. This study also reports a hybrid capacitor, which consists of cobalt oxide composite as a cathode and ruthenium oxide composite as an anode. The electrochemical performance of the hybrid capacitor is characterized by a dc charge/discharge test and cyclic voltammograms. The hybrid capacitor shows capacitor behavior with an extended operating voltage of 1.4 V. The maximum energy density and specific power density of the cell reach the value of 23.7 and 8.1 kW·g−1 respectively. The hybrid capacitor exhibits high‐energy density and stable power characteristics.
Geometric and Electronic Properties of Metallofullerene Fe@C60†
Authors: Tang Chun‐Mei , Deng Kai‐Ming , Yang Jin‐Long , Wang Xin
Published: September 2006

The generalized gradient approximation (GGA) based on density functional theory (DFT) was used to analyze the structural and electronic properties of Fe@C60 and C59Fe for comparison. Among the six possible optimized geometries of Fe@C60, the most favorable endohedral site of Fe atom is under the center of a hexagon ring, i.e., Fe@C60‐6. The Energy gap (Eg) of Fe@C60‐6 is smaller than those of C59Fe and C60, indicating the higher chemical reactivity. The magnetic moment of Fe atom in Fe@C60‐6 is preserved to some extent though there is the hybridization between the Fe atom and C atoms of the cage, in contrast to the completely quenched magnetic moment of the Fe atom in C59Fe.
A Cost‐effective Approach for 2‐(t‐Butyl)‐6‐methyl‐4H‐pyrone–A Key Intermediate Toward the Synthesis of Red‐emitting Dyes for OLED Applications†
Authors: Yao Yi‐Shan , Chuai Yu‐Tao , Wang Xue‐Song , Zhang Bao‐Wen
Published: September 2006

In the interest of driving down the cost of DCM‐type light emitting materials, we have found a new approach to prepare 2‐(t‐butyl)‐6‐methyl‐4H‐pyrone, which is cost effective and more amenable to large scale production than the reported method. Furthermore, three new DCM‐type dyes, N,N‐bis‐[p‐(2‐(4‐dicyanomethylene‐6‐t‐butyl‐4H‐ pyran‐2‐yl)‐vinyl)‐phenyl]‐4‐t‐butyl‐aniline (BDCM‐BA), N,N‐bis‐[p‐(2‐(4‐dicyanomethylene‐6‐t‐butyl‐4H‐pyran‐ 2‐yl)‐vinyl)‐phenyl]aniline (BDCM‐A) and N,N‐bis‐[p‐(2‐(4‐dicyanomethylene‐6‐t‐butyl‐4H‐pyran‐2‐yl)‐vinyl)‐ phenyl]‐4‐methoxyl‐aniline (BDCM‐MA) were synthesized in good yields using 2‐(t‐butyl)‐6‐methyl‐4H‐pyrone as starting material. They can be utilized in OLEDs as nondoped red emitting materials as the result of the restricted concentration quenching effect.
Synthesis of 1,2‐Dioxane Type Antimalarial Peroxides†
Authors: Liu He‐Hua , Zhang Qi , Jin Hong‐Xia , Shen Xin , Wu Yi‐Kang
Published: September 2006

Synthesis of five simple analogues of peroxyplakoric acid by using Kobayashi′s method to construct the key 1,2‐dioxane core is detailed.
Synthesis of a Nitro Analogue of Plakoric Acid†
Authors: Zhang Qi , Jin Hong‐Xia , Liu He‐Hua , Wu Yi‐Kang
Published: September 2006

Synthesis of a nitro analogue of plakoric acid is presented. The peroxy bond was incorporated into the substrate structure through a boron trifluoride etherate catalyzed methoxy‐hydroperoxy group partial exchange reaction in diethyl ether with urea‐hydrogen peroxide complex (UHP, a commercially available solid reagent) as the source of the hydrogen peroxide. Under the given conditions, only one of the two methoxyl groups underwent the MeO–OOH exchange and the resulting hydroperoxy hemiketal proceeded directly to the end product through an intramolecular Michael addition of the hydroperoxyl group to the nitro group activated carbon‐carbon double bond.
Proline Catalyzed Asymmetric Aldol Reaction between Methyl Ketones and α‐Ketoesters†
Authors: Wang Ya‐Jun , Shen Zong‐Xuan , Li Bin , Zhang Ya‐Wen
Published: September 2006

Direct asymmetric aldol additions of acetone/and butanone to α‐ketoesters were achieved using L‐proline as a chiral catalyst. Various optically active α‐hydroxyesters were obtained in the yields of 43%–93% with enantioselectivities up to 81% e.e. The steric effect seems to be an important factor which influences the activity and the selectivity of the reaction. Acetone showed higher reactivity than butanone while the latter provided better enantioselectivity in some cases.