Feasibility study of nitrogen removal with the mecellulose wasted liquor as an external carbon source in the two-stage denitrification process

The utilization of mecellulose wasted liquor (MWL) as an external carbon source was investigated to find an alternative for methanol in the two-stage denitrification pilot process. The pilot plant was supplied with the raw water from the J-Municipal Sewage Treatment Plant (J-MSTP) in Korea. The raw water of J-Municipal Sewage Treatment Plant contains low and high concentration of biodegradable organics and nitrogen source, respectively, due to the inflow of industrial wastewater and landfill leachate. Methanol was fed to provide external carbon source for high concentration of nitrogen source removal by denitrification in this J-Municipal Sewage Treatment Plant, and thus this study was performed to test effects to the effluent quality and efficiencies of nitrogen source removal with an alternative carbon source for the cost reduction. The 6.5mg 1(-1) and 5.7mg l(-1) of total nitrogen (TN) concentration in the effluent were achieved with mecellulose and methanol, whereas mecellulose and methanol were fed to give the same ratio of gCODgNO,-N(-1), respectively. The 60% of COD in mecellulose wasted liquor was used as a carbon source for denitrification and the stable denitrification rate was earned when one half of the required total carbon source for denitrification was fed to pre-anoxic tank in the pilot plant. The required gCODgNO,-N(-1) ratio with mecellulose wasted liquor was 1.4 times higher than with methanol. Mecellulose wasted liquor is feasible to be used as external carbon source for organic loading, nitrogen and phosphorus removal. If mecellulose wasted liquor is considered as an alternative external carbon source to substitute methanol 26-28m3 mecellulose wasted liquor per 1 m3 methanol will be required. However, to meet with the effluent standard (10 mg BOD l(-1)) for J-Municipal Sewage Treatment Plant, the feed concentration of mecellulose wasted liquor should be recommended to be lower than 200 mgl(-1).

Hydrogen-mediated spin-spin interaction in ZnCoO

The effect of hydrogen impurities on the electronic and magnetic properties of ZnO-based diluted magnetic semiconductors is examined through first-principles pseudopotential calculations. We suggest that interstitial H can mediate a strong short-ranged ferromagnetic spin-spin interaction between neighboring magnetic impurities through the formation of a bridge bond. Results based on first-principles total-energy calculations and Monte Carlo simulations indicate that such H-mediated spin-spin interactions can lead to high temperature ferromagnetism.

Direct measurements of Ab and Ac using vertex and kaon charge tags at the SLAC detector

Exploiting the manipulation of the SLAC Linear Collider electron-beam polarization, we present precise direct measurements of the parity-violation parameters A(c) and A(b) in the Z-boson-c-quark and Z-boson-b-quark coupling. Quark-antiquark discrimination is accomplished via a unique algorithm that takes advantage of the precise SLAC Large Detector charge coupled device vertex detector, employing the net charge of displaced vertices as well as the charge of kaons that emanate from those vertices. From the 1996-1998 sample of 400 000 Z decays, produced with an average beam polarization of 73.4%, we find A(c)=0.673+/-0.029(stat)+/-0.023(syst) and A(b)=0.919+/-0.018(stat)+/-0.017(syst).

Application of remote monitoring and automatic control system using neural network for small wastewater treatment plants in Korea

For this study, an automatic control system has been developed by using a neural network and internet-based remote monitoring system for efficient operation of plants that have a serious variance of influent loading and have difficulties in appropriate maintenance, just like small wastewater treatment plants in Korea. In the control algorithm, ORP was used as the main sensor for control. At the point where the ORP value was judged to reach the "nitrate knee" of denitrification and phosphorus release, ORP indicated the state of lower saturation read by the neural network and then changed the operating condition from the reduction state to the oxidation state. For example, if ORP indicates the state of higher saturation at the point of "nitrogen breakpoint" or "ammonia valley" of nitrification, the neural network reads it and cuts off the oxygen supply and mixing. The dORP data have been used as one of the main input for the neural network. After the operation of lab-scale cyclic aeration process using an automatic control system, it has been found that regardless of loading variance, more than 95% of organic matters and more than 60% of nitrogen and phosphorus have been removed. Assuming that an internet-connected computer and a basic web browser are available, this study has developed a remote monitoring system that can monitor the operating status of small plants or any troubles with them.

Hemodynamic changes in limb shaking TIA associated with anterior cerebral artery stenosis

Limb shaking TIA is a rare but well-known feature of severe carotid artery stenosis. The authors report a patient who developed recurrent shaking movements of a leg. An angiogram showed the focal stenosis of the anterior cerebral artery. Ictal and postacetazolamide SPECT scans suggested a local hyperfunction of cortical neurons and an impaired hemodynamic reserve in the vicinity of the ischemic area.

Patterns of failure in gastric carcinoma after D2 gastrectomy and chemoradiotherapy: a radiation oncologist's view

The risk of locoregional recurrence in resected gastric adenocarcinoma is high, but the benefit of adjuvant treatment remains controversial. In particular, after extended lymph node dissection, the role of radiotherapy is questionable. Since 1995, we started a clinical protocol of adjuvant chemoradiotherapy after D2 gastrectomy and analysed the patterns of failure for 291 patients. Adjuvant chemotherapy consisted of five cycles of fluorouracil and leucovorin, and concurrent radiotherapy was given with 4500 cGy from the second cycle of chemotherapy. With a median follow-up of 48 months, 114 patients (39%) showed any type of failure, and the local and regional failures were seen in 7% (20 out of 291) and 12% (35 out of 291), respectively. When the recurrent site was analysed with respect to the radiation field, in-field recurrence was 16% and represented 35% of all recurrences. Our results suggest that adjuvant chemoradiotherapy has a potential effect on reducing locoregional recurrence. Moreover, low locoregional recurrence rates could give a clue as to which subset of patients could be helped by radiotherapy after D2 gastrectomy. However, in order to draw a conclusion on the role of adjuvant radiotherapy, a randomised study is needed.

A prospective, randomized trial of endoscopic band ligation versus endoscopic hemoclip placement for bleeding gastric Dieulafoy's lesions

BACKGROUND AND STUDY AIMS

Dieulafoy's lesion is a rare cause of massive gastrointestinal hemorrhage, most commonly in the proximal stomach. Mechanical endoscopic methods have recently become the standard therapeutic approach. However, there have been few studies comparing the efficacy of different mechanical endoscopic methods in treating gastric Dieulafoy's lesions. This study was therefore carried out to compare the hemostatic efficacy and safety of endoscopic band ligation (EBL) and endoscopic hemoclip placement (EHP) in the treatment of bleeding gastric Dieulafoy's lesions.

PATIENTS AND METHODS

Between January 2002 and October 2003, 26 consecutive patients with bleeding gastric Dieulafoy's lesions were prospectively enrolled and were randomly assigned to undergo EBL (13 patients) or EHP (13 patients). Demographic characteristics, endoscopic variables, and outcome parameters, including rates of hemostasis and recurrent bleeding, were analyzed.

RESULTS

One O-ring was applied in each case in the EBL group, and the median number of hemoclips applied was one (range one to four) in the EHP group. There were no significant differences between the groups with regard to age, sex, presence of shock, initial hemoglobin level, coagulopathy, concurrent diseases, location of the lesion, type of bleeding stigmata, blood transfusion requirements, or hospitalization periods. Primary hemostasis was achieved in all 26 patients. There was one case of recurrent bleeding in each group; secondary hemostasis was achieved with EBL in one of these patients and by endoscopic epinephrine injection in the other. There were no second episodes of recurrent bleeding, no procedure-related complications, no cases in which surgery was needed, and no bleeding-related deaths in either group.

CONCLUSIONS

In this small study, no differences were detected in the efficacy or the safety of EBL vs. EHP in the management of bleeding gastric Dieulafoy's lesions.

Chromate-reducing properties of soluble flavoproteins from Pseudomonas putida and Escherichia coli

Cr(VI) (chromate) is a toxic, soluble environmental contaminant. Bacteria can reduce chromate to the insoluble and less toxic Cr(III), and thus chromate bioremediation is of interest. Genetic and protein engineering of suitable enzymes can improve bacterial bioremediation. Many bacterial enzymes catalyze one-electron reduction of chromate, generating Cr(V), which redox cycles, generating excessive reactive oxygen species (ROS). Such enzymes are not appropriate for bioremediation, as they harm the bacteria and their primary end product is not Cr(III). In this work, the chromate reductase activities of two electrophoretically pure soluble bacterial flavoproteins--ChrR (from Pseudomonas putida) and YieF (from Escherichia coli)-were examined. Both are dimers and reduce chromate efficiently to Cr(III) (kcat/Km = approximately 2 x 10(4) M(-1) x s(-1)). The ChrR dimer generated a flavin semiquinone during chromate reduction and transferred >25% of the NADH electrons to ROS. However, the semiquinone was formed transiently and ROS diminished with time. Thus, ChrR probably generates Cr(V), but only transiently. Studies with mutants showed that ChrR protects against chromate toxicity; this is possibly because it preempts chromate reduction by the cellular one-electron reducers, thereby minimizing ROS generation. ChrR is thus a suitable enzyme for further studies. During chromate reduction by YieF, no flavin semiquinone was generated and only 25% of the NADH electrons were transferred to ROS. The YieF dimer may therefore be an obligatory four-electron chromate reducer which in one step transfers three electrons to chromate and one to molecular oxygen. As a mutant lacking this enzyme could not be obtained, the role of YieF in chromate protection could not be directly explored. The results nevertheless suggest that YieF may be an even more suitable candidate for further studies than ChrR.

The vagus nerve is one route of transneural invasion for intranasally inoculated influenza a virus in mice

Intranasally inoculated neurotropic influenza viruses in mice infect not only the respiratory tract but also the central nervous system (CNS), mainly the brain stem. Previous studies suggested that the route of invasion of virus into the CNS was via the peripheral nervous system, especially the vagus nerve. To evaluate the transvagal transmission of the virus, we intranasally inoculated unilaterally vagectomized mice with a virulent influenza virus (strain 24a5b) and examined the distribution of the viral protein and genome by immunohistochemistry and in situ hybridization over time. An asymmetric distribution of viral antigens was observed between vagal (nodose) ganglia: viral antigen was detected in the vagal ganglion of the vagectomized side 2 days later than in the vagal ganglion of the intact side. The virus was apparently transported from the respiratory mucosa to the CNS directly and decussately via the vagus nerve and centrifugally to the vagal ganglion of the vagectomized side. The results of this study, thus, demonstrate that neurotropic influenza virus travels to the CNS mainly via the vagus nerve.

Doping by large-size-mismatched impurities: the microscopic origin of arsenic- or antimony-doped p-type zinc oxide

Based on first-principles calculations, a model for large-size-mismatched group-V dopants in ZnO is proposed. The dopants do not occupy the O sites as is widely perceived, but rather the Zn sites: each forms a complex with two spontaneously induced Zn vacancies in a process that involves fivefold As coordination. Moreover, an As(Zn)-2V(Zn) complex may have lower formation energy than any of the parent defects. Our model agrees with the recent observations that both As and Sb have low acceptor-ionization energies and that to obtain p-type ZnO requires O-rich growth or annealing conditions.

Persistence of viral RNA segments in the central nervous system of mice after recovery from acute influenza A virus infection

One-hundred thirty-seven BALB/c mice were intranasally inoculated with neurotropic avian influenza A virus (H5N3). Thirty-nine of these mice died within 16 days post-inoculation (PID) and 98 of the mice recovered from the infection. To investigate whether viral antigens and genomes persist in the central nervous system (CNS) of recovered mice, immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) methods were performed. Histopathologically, mild interstitial pneumonia and non-suppurative encephalomyelitis restricted to the basal part of the frontal lobe of the cerebrum, brain stem and thoracic spinal cord were observed in BALB/c mice until 40 PID. Small amounts of viral antigens were detected in the brain and spinal cord and some viral RNA segments (NA, NP, M, PA, HA, NS, PB1) were intermittently detected in the CNS until 48 PID. Immunosuppression of these mice by dexamethazone (DEX) treatment did not increase the frequency of detection of the lesions, viral antigens or genomes. These findings suggest that viral genomes of neurovirulent influenza virus persist with restricted transcriptive activity in the CNS of the mice even after clinical recovery from the infection.

The effects of antipyretics on influenza virus encephalitis in mice and chicks

To investigate the effect of antipyretics on the murine and poultry models of influenzal encephalitis, we injected large quantities of antipyretics, acetylsalicylic acid (aspirin) and dicrofenac sodium (voltaren). The effect of antipyretic treatment on the murine encephalitis model was unremarkable histologically and immunohistochemically. Whereas in chicks, CNS lesions consisting of perivascular cuffing and gliosis appeared only in those animals treated with the antipyretics and viral antigen was detected mainly in the nuclei of glial cells or vascular endothelia of voltaren-treated animals. We here demonstrate that antipyretic treatment aggravated the hematogenous spread of the influenza virus to the CNS in chicks, but did not affect the transneural infection in mice.

Automatic control and remote monitoring system for biological nutrient removal on small wastewater treatment plants in Korea

Many small-size wastewater treatment plants in Korea's rural communities are designed to remove organic and suspended matter only, and they generally show a large fluctuation in the influent loading compared to municipal wastewater treatment plants (MWWTPs). They also have no professional engineers stationed for efficient operation against mechanical breakdown. For those reasons, the wastewater treatment plants have low efficiency in treatment of nitrogen and phosphorus as well as organic matter. In order to solve those problems, this study developed an automatic control system and RMS (remote monitoring system), which can keep efficiency stable despite any change in the small plants' loading rates and are capable of removing nutrient materials such as nitrogen or phosphorus. According to the results of the Experimental SBR system of the automatic control program, complete nitrification was made under oxic conditions and denitrification occurred as NO3-N concentration decreased by 0.5 mg/l in anoxic conditions and excellent nitrogen removal efficiency was seen generally. The Experimental SBR system created "phosphate release and uptake" effectively and displayed phosphate-removing efficiency up to more than 80% as the concentration of effluent was kept low by 0.4 mg/l. RMS developed in this study transmits a plant's data and operation states to clients in remote locations in real-time interval through the Internet. Therefore, although you are in a remote location, it allows you to see if a plant is properly operated or there is any breakdown.

Endoscopic band ligation for control of acute peptic ulcer bleeding

BACKGROUND AND STUDY AIMS

The use of endoscopic band ligation (EBL) is being extended to treat various causes of upper and lower gastrointestinal bleeding. The aim of this study was to evaluate the usefulness of EBL for control of acute peptic ulcer bleeding and to define the lesions that are most suitable for this technique.

PATIENTS AND METHODS

19 patients with major stigmata of acute peptic ulcer bleeding were treated using EBL; 11 patients had active bleeding and eight patients had a nonbleeding visible vessel.

RESULTS

The site of acute peptic ulcer bleeding was the stomach in 12 patients, the duodenum in four patients, and Billroth II anastomosis in three. Initial hemostasis was achieved in 19 patients (100 %) in a single session. There were no rebleeding episodes in any of the patients, and there was no bleeding-related or procedure-related death. During long-term outpatient follow-up, bleeding did not recur.

CONCLUSIONS

EBL is an effective and safe endoscopic treatment for small-sized nonfibrotic acute peptic ulcer bleeding. Larger studies in patients with acute peptic ulcer bleeding are needed to confirm these promising results.

Comparison of a Commercial Reversed Passive Latex Agglutination Assay to an Enzyme Immunoassay for the Detection of Shiga Toxin-Producing Escherichia coli

A multicenter study was performed to compare the performance of a prototypic reversed passive latex agglutination assay (VTEC Screen "Seiken"; Denka-Seiken, Japan) with the Premier EHEC Enzyme Immunoassay (Meridian Diagnostics, USA) for the detection of Shiga toxin in 554 diarrheal stool samples. Standard culture on sorbitol MacConkey agar and the use of latex agglutination reagents were included to identify the Escherichia coli O157, O26 and O111 serotypes. There was 99% agreement between the VTEC screen and enzyme immunoassay (kappa=0.823). Seventeen samples were positive for toxin by one or both assays. One toxin-positive sample using the enzyme immunoassay and four positive samples using the VTEC Screen could not be confirmed. Serotypes identified included: O157:H7 (n=8), O26 (n=2), O111 (n=1) and O45:H2 (n=1). The VTEC screen is easy to perform and comparable to the Meridian EHEC test for detection of Shiga toxin in clinical samples.

Postoperative chemoradiotherapy for gastric cancer

BACKGROUND

We report the results of postoperative chemoradiotherapy after curative resection in gastric cancer patients.

PATIENTS AND METHODS

Patients with gastric cancer staged IB to IV(M0) were treated with chemoradiotherapy after curative resection with extensive (D2) lymph node dissection. Nodal metastases were observed in 261 (90%) patients. The chemotherapy consisted of fluorouracil 400 mg/m(2) plus leucovorin 20 mg/m(2) for 5 days, followed by 4500 cGy of radiotherapy for 5 weeks with fluorouracil and leucovorin on the first 4 days and the last 3 days of radiotherapy. Two 5-day cycles of chemotherapy were given 4 weeks after the completion of radiotherapy.

RESULTS

Of 290 patients accrued, 229 (79%) patients completed chemoradiotherapy as planned. With a median follow-up of 49 months, 114 (34%) patients have relapsed: 33 (29%) locoregional relapses, 76 (67%) peritoneal relapses and 41 (36%) distant metastases. The 5-year overall and relapse-free survivals were 60% and 57%, respectively. Tolerance was acceptable, the main toxicity being neutropenia.

CONCLUSIONS

This postoperative chemoradiotherapy after curative resection of gastric cancer was feasible, with acceptable toxicities. Whether this adjuvant therapy in gastric cancer patients that have undergone a D2 lymph node dissection impacts on survival or reduces the incidence of relapses remains to be studied.

Abdominal amyloidosis: spectrum of radiological findings

Amyloidosis is a disease characterized by the deposition of fibrillar protein amyloid of beta-structure in organs or tissues. It is usually classified as either a primary disease or secondary to a co-existent condition, such as rheumatoid arthritis, tuberculosis, or neoplasm (particularly multiple myeloma or renal cell carcinoma). Amyloid protein deposition can be seen in a variety of organs though it occurs with higher frequency in the gastrointestinal tract, kidney, and heart. Amyloidosis can have a wide spectrum of manifestations in nearly every abdominal organ. Some of these, for example, multiple cystic submucosal masses of the stomach, amyloidosis of the gallbladder, and dirty soft tissue infiltration of the subcutaneous fat, have not yet been covered in the radiological literature. The combination of various imaging techniques and the identification of characteristic computed tomography (CT) hepatic features may help in the differentiation of amyloidosis from other infiltrative diseases; however, confirmative diagnosis can usually only be achieved by tissue biopsy.

Evaluation of the duopath verotoxin test for detection of shiga toxins in cultures of human stools

The Duopath Verotoxin test (Merck KgaA, Darmstadt, Germany) is a newly developed immunochromatographic test for the confirmation of Shiga toxin (Stx)-producing Escherichia coli (STEC) strains from food products. This test detects both Stx 1 (Stx1)-positive and Stx2-positive samples individually with the same device. By modification of the original protocol, the present study evaluated its performance and feasibility for clinical application with human stool samples, consisting of 41 frozen samples known to contain STEC isolates (O157:H7 and non-O157 serotypes) and 250 fresh specimens. The test specimens were polymyxin B extracts of colony sweeps taken from overnight sorbitol-MacConkey agar cultures of stools containing STEC isolates and other bacteria. All 41 frozen STEC-positive stool samples were positive by the Duopath Verotoxin test, as were 2 fresh stool samples with culture-confirmed STEC O157 infection. Thus, 100% sensitivity and no false-positive results were obtained when the Premier EHEC assay (Meridian Bioscience, Cincinnati, Ohio) was used as the "gold standard." The Duopath Verotoxin test is simple to perform and easy to interpret, providing a turnaround time of 24 h. Despite its original intended use, the Duopath Verotoxin test has a great potential for clinical application.

The usefulness of endoscopic hemoclipping for bleeding Dieulafoy lesions

BACKGROUND AND STUDY AIMS

Dieulafoy lesion is a rare cause of massive gastrointestinal hemorrhage, most commonly from the proximal stomach. Surgery was regarded as the treatment of choice in the past, but recently endoscopic management has become the standard approach. However, the effectiveness of various endoscopic modalities in treating bleeding Dieulafoy lesion has been little studied. This study was therefore done to compare the hemostatic efficacy of endoscopic hemoclipping and epinephrine injection therapy.

PATIENTS AND METHODS

Between January 1998 and December 2001, a consecutive series of 32 patients with bleeding Dieulafoy lesion underwent endoscopic treatment. They were randomly treated either by endoscopic epinephrine injection therapy (n = 16) or by hemoclipping (n = 16). We compared mortality rate, primary hemostasis rate, and rebleeding rate between two groups.

RESULTS

There was no bleeding-related death in either group. There was no significant difference in primary hemostasis rates between the hemoclipping group (93.8 %) and epinephrine injection group (87.5 %, P = 1.00). There was a trend toward a lower rate of need for multiple endoscopic sessions to achieve permanent hemostasis in the hemoclipping group compared with the epinephrine injection group (6.3 % vs. 31.3 %, P = 0.086). Hemoclipping was significantly more effective in preventing recurrent bleeding than epinephrine injection therapy (0 % vs. 35.7 %, P < 0.05). With regard to lesion site, hemoclipping was significantly more effective in preventing recurrent bleeding of gastric body Dieulafoy lesion than epinephrine injection therapy (0 % vs. 50 %, P < 0.05).

CONCLUSIONS

Bleeding from Dieulafoy lesion was well controlled by therapeutic endoscopic procedures. Hemoclipping was more effective for Dieulafoy lesion than epinephrine injection therapy, with less need for subsequent endoscopy.

Improved direct measurement of the parity-violation parameter Ab using a mass tag and momentum-weighted track charge

We present an improved direct measurement of the parity-violation parameter A(b) in the Z boson-b-quark coupling using a self-calibrating track-charge technique applied to a sample enriched in Z-->bb events via the topological reconstruction of the B hadron mass. Manipulation of the Stanford Linear Collider electron-beam polarization permits the measurement of A(b) to be made independently of other Z-pole coupling parameters. From the 1996-1998 sample of 400,000 hadronic Z decays, produced with an average beam polarization of 73.4%, we find A(b)=0.906+/-0.022(stat)+/-0.023(syst).

A double-blind, randomised- placebo, controlled, parallel group, multicentre, flexible-dose escalation study to assess the efficacy and safety of sildenafil administered as required to male outpatients with erectile dysfunction in Korea

The efficacy and safety of sildenafil was evaluated in a randomiSed, double-blind, placebo-controlled, flexible-dose study in Korean men aged 28-78 y with erectile dysfunction (ED) of broad-spectrum aetiology and more than 6 months duration. A total of 133 patients were randomised at six centres in Korea to receive either sildenafil (50 mg initially, increased if necessary to l00 mg or decreased to 25 mg depending on efficacy and tolerance) (n=66) or matching placebo (n=67) taken on an 'as needed' basis l h prior to anticipated sexual activity for a period of 8 weeks. At the end of this time, the primary efficacy variables relating to the achievement and maintenance of erections sufficient for sexual intercourse, and the secondary efficacy variables, which included: (1) the five separate domains of sexual functioning of the International Index of Erectile Function (IIEF) scale, (2) the percentage of successful intercourse attempts, and (3) a global assessment of erections, were all statistically significantly improved by sildenafil in comparison with placebo (P&<0.0001). Treatment-related adverse events occurred in 56.1% of patients receiving sildenafil and 20.9% receiving placebo. The most common adverse events with sildenafil were vasodilatation (flushing), headache and abnormalities in colour vision (31.8, 22.7 and 6.1% of patients, respectively), and most were mild in nature. The efficacy and safety of sildenafil in this population of Korean men appears similar to that reported in other studies in western populations.