[Clinical analysis of carotid artery stenting with severe stenosis and extracranial distortion under proximal protection technique].

Objective: To investigate the feasibility, efficacy and safety of endovascular reconstruction of the carotid artery with severe stenosis and extracranial distortion under proximal protection. Methods: A retrospective analysis of 21 patients with severe carotid stenosis and extracranial distortion who were admitted to the Second Affiliated Hospital of Soochow University between January 2011 and August 2017, of which 16 patients were symptomatic stenosis with acute ischemic stroke. All the patients were treated with carotid artery stenting under (CAS) proximal protection technique, and assessed with the National Institutes of Health Stroke Scale (NIHSS) before the treatment and hospital discharge. The clinical outcome and vascular morphology were followed-up regularly after the treatment. Results: Twenty-one patients were successfully completed the CAS procedure under the proximal protection technique, the average blocking time was 241.0 (232.5-261.0) seconds. Nine patients received 1block attempt, 6 patients received 2 block attempts, and the other 6 patients received 3 block attempts. Three patients experienced transient ischemic attack (TIA) during the procedure, the maximum duration of TIA was 10 minutes. In 16 patients with symptomatic stenosis, there were no significant differences in NIHSS score before CAS procedure and hospital discharge (P>0.05). The residual stenosis rate of the carotid artery after stenting was(13±6)%, compared with preoperative (87±16)%, which appeared a significant difference (t=19.948, P<0.05). All the patients had no adverse events such as myocardial infarction, recurrent ischemic stroke and death in the follow-up period. Restenosis was assessed in 6 patients by DSA or CTA and no restenosis was found. Conclusion: Endovascular reconstruction of the carotid artery with severe stenosis and extracranial distortion under proximal protection technique has been proven as a safe and effective therapy.

Efficacy of Mechanical Thrombectomy Using Stent Retriever and Balloon-Guiding Catheter.

PURPOSE: Intra-arterial therapy of acute ischemic stroke has developed rapidly in recent years. Due to proven efficacy in randomized trials, stent retrievers were replacing first-generation thrombectomy devices and have been defined as method of choice. However, aspiration catheters or a combination of several techniques have shown promising rates of successful recanalizations. To create a basis for comparison of the new approaches according to real-world data, we determined the first pass recanalization rate of an evidence-based standard technique with the use of a stent retriever in combination with a balloon-guiding catheter. The assessment was based on the number of required passages and reperfusion rate, but not on clinical results. METHODS: Patients from our institution with anterior circulation occlusions and mechanical thrombectomy by using stent retrievers in combination with balloon-guiding catheters were analyzed retrospectively. Reperfusion was graded with the "thrombolysis in cerebral infarction" (TICI) classification on post-interventional angiograms. Additionally, the number of passes and the duration of the recanalization procedure were recorded. RESULTS: Between 2014 and July 2017, 201 patients met the inclusion criteria. Successful recanalization, defined as a TICI scale 2b/3, was 91% (TICI 2b was achieved in 44% and TICI 3 in 47%) after the procedure. After the first passage, successful recanalization was achieved in 65% of the patients. Mean number of passes was 1.4 (1-5 passes) for all patients. Median duration of the procedure was 49 min (0:11-2:35 h). CONCLUSIONS: Even a standard thrombectomy technique with the use of a stent retriever together with a balloon-guiding catheter provides reasonable recanalization rates with only one passage. The results can be taken as benchmark for alternative and more complex techniques.

Prognostic role of hypochloremia in acute ischemic stroke patients.

OBJECTIVES: The impact of electrolyte imbalance on clinical outcomes after acute ischemic stroke (AIS) is still not understood. We investigated the association between hypochloremia and hyponatremia upon hospital admission and in-hospital mortality in AIS patients. MATERIALS AND METHODS: A total of 3314 AIS patients enrolled from December 2013 to May 2014 across 22 hospitals in Suzhou city were included in this study. Hypochloremia was defined as having a serum chloride concentration <98 mmol/L and hyponatremia as having a serum sodium concentration <135 mmol/L. The Cox proportional hazard model was used to examine the effect of hypochloremia and hyponatremia on all-cause in-hospital mortality in AIS patients. RESULTS: During hospitalization, 118 patients (3.6%) died from all causes. Multivariable model adjusted for age, sex, baseline National Institutes of Health Stroke Scale score, serum sodium, and other potential covariates showed that hypochloremia was associated with a 2.43-fold increase in the risk of in-hospital mortality (hazard ratio [HR] 2.43; 95% confidence interval [CI], 1.41-4.19; P=.001). However, no significant association between hyponatremia (P=.905) and in-hospital mortality was observed. Moreover, the multivariable analysis found that serum chloride (HR=0.92, 95% CI 0.88-0.98; P=.004) but not serum sodium (P=.102) was significantly associated with in-hospital mortality. CONCLUSIONS: Hypochloremia at admission was independently associated with in-hospital mortality in AIS patients.

Effects of increasing nurse staffing on missed nursing care.

BACKGROUND: Inadequate nurse staffing has been reported to lead nurses to omit required nursing care. In South Korea, to reduce informal caregiving by patient families and sitters and to improve the quality of nursing care, a public hospital operated by the Seoul Metropolitan Government has implemented a policy of increasing nurse staffing from 17 patients per registered nurse to 7 patients per registered nurse in 4 out of 13 general nursing units since January 2013. AIM: The study aims to compare missed nursing care (omission of required care) in high-staffing (7 patients per nurse) units vs. low-staffing (17 patients per nurse) units to examine the effects of nurse staffing on missed care. METHODS: A nurse survey conducted in July 2013 targeted all staff nurses in all four high-staffing and all nine low-staffing units; 115 nurses in the high-staffing units (response rate = 94.3%) and 117 nurses in the low-staffing units (response rate = 88.6%) participated. Missed nursing care was measured using the MISSCARE survey that included 24 nursing care elements. Nurses were asked how frequently they had missed each element on a 4-point scale from 'rarely' to 'always'. RESULTS: Overall, nurses working in high-staffing units had a significantly lower mean score of missed care than those in low-staffing units. Seven out of 24 nursing care elements were missed significantly less often in high-staffing (vs. low-staffing) units: turning, mouth care, bathing/skin care, patient assessments in each shift, assistance with toileting, feeding and setting up meals. CONCLUSION: The findings suggest that increasing nurse staffing is associated with a decrease in missed care. Less omission of required nursing care is expected to improve nursing surveillance and patient outcomes, such as patient falls, pressure ulcers and pneumonia. IMPLICATIONS FOR NURSING AND HEALTH POLICY: Adequate nurse staffing should be ensured to reduce unmet nursing needs and improve patient outcomes.

Morphometry of the pituitary gland and hypothalamus in long-term survivors of childhood trauma.

PURPOSE: Chronic pituitary dysfunction is increasingly recognized as a sequela of traumatic brain injury (TBI). Our aim was to rule out any late morphometric changes of the pituitary gland and hypothalamus in survivors of TBI during childhood requiring intensive care. METHODS: We assessed morphometric abnormalities of the sella region and hypothalamus in patients who sustained TBI during childhood. The patients showed no clinical hormonal dysfunction at the acute phase and pituitary hormone levels at the time of our study were within normal limits. From the 18 enrolled patients in the magnetic resonance study, five were removed due to morphological changes or anatomical variations. We studied the MRI of 13 male survivors (mean age 27 years, mean time after trauma 20 years) and compared them to 13 male control subjects who were matched in terms of age (mean age, 26 years), education and ethnicity. Analyses of the pituitary gland and sella on a midsagittal T2- and T1-weighted image were performed. We used voxel-based morphometry (VBM), an unbiased MRI morphometric method to investigate hypothalamic region in this group of patients. RESULTS: There was only a trend towards a reduced pituitary gland width in the patient group compared to controls. However, no significant morphological and morphometric abnormality was seen and VBM showed no hypothalamic grey matter loss. CONCLUSION: In the absence of hormonal dysfunction, no persisting morphometric changes of the pituitary gland and hypothalamus were seen in survivors of childhood TBI requiring intensive care.

Mercury recovery from cold cathode fluorescent lamps using thermal desorption technology.

Cold cathode fluorescent lamps (CCFLs) are globally used components of high technology products. A large amount of mercury in waste CCFLs is being recovered by thermal desorption technology in Taiwan. However, the complexity of the samples affects the thermal desorption efficiency and increases costs. This study identifies the mercury release behaviour of amalgam, phosphor and mercury-containing components as well as waste CCFLs by bench scale thermal desorption test. The results show that the mercury was released from amalgam and mercury/fluorescent powder from a real treatment plant at temperatures between 550 degrees C to 850 degrees C, which is much higher than from cinnabar at 300 degrees C to 380 degrees C and that of pure mercury, high pressure mercury lamps, and fluorescent tubes containing mercury/fluorescent-powder at 50 degrees C to 250 degrees C. In addition, the experiment also showed the mercury release peak of the mercury/fluorescent powders from a real treatment plant occurs at much higher temperatures than that of commercial phosphor at 50 degrees C to 200 degrees C. Thus, complete separation of the cracked CCFLs is necessary to effectively recover phosphor and mercury at low financial and energy cost.

A material flow of lithium batteries in Taiwan.

Li batteries, including secondary and cylindrical/button primary Li batteries, are used worldwide in computers, communications and consumer electronics products. However, there are several dangerous issues that occur during the manufacture, shipping, and storage of Li batteries. This study analyzes the material flow of lithium batteries and their valuable heavy metals in Taiwan for the year 2006 by material flow analysis. According to data from the Taiwan Environmental Protection Administration, Taiwan External Trade Development Council, Bureau of Foreign Trade, Directorate General of Customs, and the Li batteries manufactures/importers/exporters. It was found that 2,952,696 kg of Li batteries was input into Taiwan for the year 2006, including 2,256,501 kg of imported Li batteries and 696,195 kg of stock Li batteries in 2005. In addition, 1,113,867 and 572,215 kg of Li batteries was domestically produced and sold abroad, revealing that 3,494,348 kg of different types of Li batteries was sold in Taiwan. Of these domestically sold batteries, 504,663 and 146,557 kg were treated domestically and abroad. Thus, a total of 2,843,128 kg of Li batteries was stored by individual/industry users or illegally disposed. In addition, it was also observed that 2,120,682 kg of heavy metals contained in Li batteries, including Ni, Co, Al, Cu and Ni, was accumulated in Taiwan, with a recycled value of 38.8 million USD. These results suggest that these heavy metals should be recovered by suitable collection, recycling and reuse procedures.

Treating high-mercury-containing lamps using full-scale thermal desorption technology.

The mercury content in high-mercury-containing lamps are always between 400 mg/kg and 200,000 mg/kg. This concentration is much higher than the 260 mg/kg lower boundary recommended for the thermal desorption process suggested by the US Resource Conservation and Recovery Act. According to a Taiwan EPA survey, about 4,833,000 cold cathode fluorescent lamps (CCFLs), 486,000 ultraviolet lamps and 25,000 super high pressure mercury lamps (SHPs) have been disposed of in the industrial waste treatment system, producing 80, 92 and 9 kg-mercury/year through domestic treatment, offshore treatment and air emissions, respectively. To deal with this problem we set up a full-scale thermal desorption process to treat and recover the mercury from SHPs, fluorescent tube tailpipes, fluorescent tubes containing mercury-fluorescent powder, and CCFLs containing mercury-fluorescent powder and monitor the use of different pre-heating temperatures and desorption times. The experimental results reveal that the average thermal desorption efficiency of SHPs and fluorescent tube tailpipe were both 99.95%, while the average thermal desorption efficiencies of fluorescent tubes containing mercury-fluorescent powder were between 97% and 99%. In addition, a thermal desorption efficiency of only 69.37-93.39% was obtained after treating the CCFLs containing mercury-fluorescent powder. These differences in thermal desorption efficiency might be due to the complexity of the mercury compounds contained in the lamps. In general, the thermal desorption efficiency of lamps containing mercury-complex compounds increased with higher temperatures.

Continuous electricity production from leachate in a novel upflow air-cathode membrane-free microbial fuel cell.

In this study, a novel microbial fuel cell, i.e. upflow air-cathode membrane-free microbial fuel cell (UAMMFC) was reported and its performance in electricity generation from original leachate was examined. The experimental results demonstrated that the UAMMFC could continuously generate electricity from leachate (0.3V; REX=150 Omega) for an operational period of time (50 h). The maximum volumetric power reached 12.8 W/m3 at current density of 41 A/m3 (93 Omega). NH4+-N elimination from the leachate was shown to be a consequence of electrochemistry-independent oxidation occurred in the MFC. Increasing organic loading rate from 0.65 to 5.2 kgCOD/m3 d resulted in a decrease of overall Coulombic efficiency (CE) from 14.4% to 1.2%. The low CE obtained here should be attributed to severe oxygen diffusion from the open-to-air cathode.

Efficacy and prognosis of a short course of prednisolone therapy for pediatric epilepsy.

PURPOSE: To evaluate the efficacy and safety of adjunctive prednisolone therapy in children with cryptogenic epileptic encephalopathy, other than infantile spasms, and to determine its prognosis. METHODS: Prednisolone, 2mg/kg per day for 6 weeks, tapered for a further 2 weeks, was given in combination with previously prescribed antiepileptic drugs. A retrospective assessment of 41 children thus treated included measurements of seizure frequency, electroencephalographic findings, global assessments of cognitive function, and adverse drug events. Long-term patient prognoses over a mean follow-up period of 3 years and 5 months (range, 14-90 months) were also examined. RESULTS: Of 41 patients, 32 had Lennox-Gastaut syndrome, 4 had Doose syndrome, 1 had Otahara syndrome, 2 had Landau-Kleffner syndrome, and 2 had other unspecified generalized epilepsies. After prednisolone therapy, 73% (30/41) of patients showed a reduction in seizure frequency of >50%, and 59% (24/41) became seizure free. However, only seven patients (four with Lennox-Gastaut syndrome, two with Doose syndrome, and one with unspecified generalized epilepsy) who became seizure free remained free of seizures at the time of the final follow-up. Electroencephalographic findings and global assessments of cognitive function correlated well with seizure outcomes. No significant demographic factors influenced the efficacy of prednisolone or patient prognoses after prednisolone tapering. Most adverse events were transient, or were tolerated well with conservative management, with maintenance of the medication. CONCLUSION: Prednisolone therapy may be a safe and effective adjunct in patients with cryptogenic epileptic encephalopathies, but the high relapse rate is of concern.

Performance and microbial diversity of a membrane bioreactor treating real textile dyeing wastewater.

The textile industry is one of the major industries of Taiwan but unfortunately it produces toxic and low biodegradable wastewater. To remedy this problem, this study compared the performance of the membrane bioreactor (MBR) and sequencing batch reactor (SBR) processes for treating real textile dyeing wastewater. The microbial diversity of the MBR process was also identified by a combination of culturing methods and molecular biotechnology. The removal efficiencies of the MBR process for color, COD, BOD, and SS were 54, 79, 99, and 100%, respectively, all higher than the corresponding parameters for the SBR process: i.e., 51, 70, 96, and 60%. All the above four parameters for the MBR effluent meet the criteria of the Taiwan EPA, while on the other hand, for the SBR process, only color and COD meet the Taiwan EPA effluent criteria. Furthermore, the genus Microbacterium, in particular Microbacterium aurum, was the most predominant population, accounting for 70.6% of the total isolates, and might be responsible for the degradation of the dyeing wastewater. Another two textile dyeing degradation bacteria, Paenibacillus azoreducens and Bacillus sp., were also observed as predominant bacteria in MBR sludge.

Abnormal heating of low-energy electrons in low-pressure capacitively coupled discharges.

In low-pressure capacitively coupled plasmas, high-energy electrons are collisionlessly heated by large rf fields in the sheaths while low-energy electrons are confined in the bulk plasma by the ambipolar potential. Low-energy electrons are typically inefficiently heated due to their low collisionality and the weak rf electric field present in the bulk. It is shown, however, that as a result of the nonlinear interaction between the electron motion and the weak rf field present in the bulk, low-energy electrons can be efficiently heated. Electrons in the bulk that bounce inside the electrostatic potential well with a frequency equal to the rf excitation frequency are efficiently heated by the coherent interaction with the rf field. This resonant collisionless heating can be very efficient and manifest itself as a plateau in the electron energy probability function.

The fate and management of high mercury-containing lamps from high technology industry.

This study investigated the fate and management of high mercury-contained lamps, such as cold cathode fluorescent lamps (CCFLs), ultraviolet lamps (UV lamps), and super high pressure mercury lamps (SHPs), from high technology industries in Taiwan, using material flow analysis (MFA) method. Several organizations, such as Taiwan Environmental Protection Administration, Taiwan External Trade Development Council, the light sources manufactories, mercury-containing lamps importer, high technology industrial user, and waste mercury-containing lamps treatment facilities were interviewed in this study. According to this survey, the total mercury contained in CCFLs, UV lamps, and SHPs produced in Taiwan or imported from other countries was 886kg in year 2004. Among the various lamps containing mercury, 57kg mercury was exported as primary CCFLs, 7kg mercury was wasted as defective CCFLs, and 820kg mercury was used in the high technology industries, including 463kg mercury contained in exported industrial products using CCFLs as components. On the contrary, only 59kg of mercury was exported, including 57kg in CCFLs and 2kg in UV lamps. It reveals that 364kg mercury was consumed in Taiwan during year 2004. In addition, 140kg of the 364kg mercury contained in lamps used by high technology industry was well treated through industrial waste treatment system. Among the waste mercury from high technology industry, 80kg (57%), 53kg (38%), and 7kg (5%) of mercury were through domestic treatment, offshore treatment, and emission in air, respectively. Unfortunately, 224kg waste mercury was not suitable treated, including 199kg mercury contained in CCFL, which is a component of monitor for personal computer and liquid crystal display television, and 25kg non-treated mercury. Thus, how to recover the mercury from the waste monitors is an important challenge of zero wastage policy in Taiwan.

Simultaneous removal of ammonium-nitrogen and sulphate from wastewaters with an anaerobic attached-growth bioreactor.

Some industrial wastewaters may contain ammonium-nitrogen and/or sulphate, which need to be removed before their discharge into natural water bodies to eliminate their severe pollution. In this paper, simultaneous removal of ammonium-nitrogen and sulphate with an anaerobic attached-growth bioreactor of 3.8 L incubated with sulphate reducing bacteria (SRB) was investigated. Artificial wastewater containing sodium sulphate as electron acceptor, ammonium chlorine as electron donor and glucose as carbon source for bacteria growth was used as the feed for the bioreactor. The loading rates of ammonium-nitrogen, sulphate and COD were 2.08 gN/m3 x d, 2.38 gS/m3 x d, 104.17 gCOD/m3 x d, respectively, with a N/S ratio of 1:1.14. The results demonstrated that removal rates of ammonium-nitrogen, sulphate and COD could reach 43.35%, 58.74% and 91.34%, respectively. Meanwhile, sulphur production was observed in effluent as well as molecular nitrogen in biogas, whose amounts increased with time substantially, suggesting the occurrence of simultaneous removal of ammonium-nitrogen and sulphate. This novel reaction provided the possibility to eliminate ammonium-nitrogen and sulphate simultaneously with accomplishment of COD removal from wastewater, making wastewater treatment more economical and sustainable.

Pretreatment with simvastatin reduces myocardial no-reflow by opening mitochondrial K(ATP) channel.

BACKGROUND AND PURPOSE: Simvastatin, a cholesterol-lowering agent, can protect against endothelial dysfunction. However, the effects of simvastatin treatment on the restoration of blood flow to ischemic myocardium are not known. This study sought to assess such effects of simvastatin on an experimental model of myocardial no-reflow and to explore possible mechanisms. EXPERIMENTAL APPROACH: Coronary ligation area and area of no-reflow were determined by myocardial contrast echocardiography in vivo and by histology in mini-pigs randomized into 7 study groups: controls, pretreated with simvastatin for 2 days, treated with 5-hydroxydecanoate (5-HD, the selective mitochondrial K(ATP) channel blocker), treated with simvastatin+5-HD, treated with HMR 1883 (the selective sarcolemmal K(ATP) channel blocker), treated with simvastatin+HMR 1883 and a sham-operated group. The myocardial no-reflow model was induced with 3 h occlusion of the left anterior descending coronary artery followed by 2 h reperfusion. KEY RESULTS: Compared with the control group, simvastatin significantly increased coronary blood flow, decreased the area of no-reflow assessed echocardiographically and reduced the necrotic area, by histology. There was no significant difference in these outcomes between simvastatin and simvastatin+HMR 1883 groups. In contrast, 5-HD abolished the effect of simvastatin. CONCLUSIONS AND IMPLICATIONS: Simvastatin can reduce the area and myocardial no-reflow after ischaemia and reperfusion. This beneficial effect is due to its activation of mitochondrial K(ATP) channels.

Improving the removal of anions by coagulation and dissolved air flotation in wastewater reclamation.

This study investigated the feasibility of improving the removal of anions from a secondary effluent by coagulation/flocculation (Coag/Floc) and dissolved air flotation (DAF) using a pilot-scale wastewater reclamation plant in a high-tech industrial park. The pilot plant was equipped with units of Coag/Floc, DAF, activated carbon beds (AC), microfiltration modules (MF) and a reverse-osmosis membrane (RO). It was operated in-situ continuously for around one year to evaluate the performance of anion removal in two processes - the AC-RO process and the DAF-AC-RO process. Long-term experimental results indicated that combining Coag/Floc, DAF and AC units increased the potential of pretreatment to remove anions. The removal efficiencies in Coag/Floc-DAF units were in the order phosphate > fluoride > chloride > sulfate > silicate. The charged complex of PACl flocs revealed a higher affinity for adsorption onto phosphate and fluoride than on chloride, sulfate and silicate. Comparison of the performance of Coag/Floc-DAF-AC units in the DAF-AC-RO process with that of a single AC unit in the AC-RO process demonstrated that adding Coag/Floc-DAF units increased the removal efficiencies of phosphate, fluoride and silicate by approximately 70.0%, 42.7% and 70.1%, respectively. Most of the phosphate and fluoride were removed in Coag/Floc-DAF units, while most of the silicate escaped from the Coag/Floc-DAF units, and was adsorbed and/or trapped in the AC unit. The quality of reclaimed water in the DAF-AC-RO process complied with the requirements of high-tech industries in cleaning processes. Combined units of Coag/Floc-DAF-AC were therefore recommended for use in pretreatment in wastewater reclamation in high-tech industrial parks.

Different effects of tirofiban and aspirin plus clopidogrel on myocardial no-reflow in a mini-swine model of acute myocardial infarction and reperfusion.

OBJECTIVE: To compare the effects of an aspirin-clopidogrel combination with those of the specific glycoprotein IIb/IIIa inhibitor tirofiban on myocardial no-reflow, nitric oxide concentration and activity of nitric oxide synthase (NOS) isoforms in a mini-swine model of acute myocardial infarction and reperfusion. METHODS: Area of no-reflow was determined by both myocardial contrast echocardiography and pathological means in 40 mini-swine randomly assigned to five study groups: eight controls, eight pretreated with aspirin-clopidogrel combination for three days, eight given an intravenous infusion of tirofiban, eight treated with ischaemic preconditioning and eight sham operated. The acute myocardial infarction and reperfusion model was created with 3 h occlusion of the left anterior descending coronary artery followed by 1 h reperfusion. RESULTS: Compared with the control group, tirofiban significantly decreased the area of no-reflow assessed echocardiographically and pathologically, from 78.5% to 22.8% and 82.3% to 23.2%, respectively (both p < 0.01), and increased blood nitric oxide concentration (p < 0.05), enhanced constitutive NOS activity from 0.51 to 0.81 U/mg protein and mRNA expression from 0.47% to 0.66%, but decreased inducible NOS activity from 0.76 to 0.41 U/mg protein and mRNA expression from 0.54% to 0.39% in reflow myocardium (all p < 0.05-0.01). In contrast, the aspirin-clopidogrel combination did not significantly modify the above parameters (all p > 0.05) except for decreasing inducible NOS activity from 0.76 to 0.39 U/mg protein (p < 0.01) and mRNA expression from 0.54% to 0.40% (p < 0.05). CONCLUSIONS: Tirofiban is very effective in attenuating myocardial no-reflow; in contrast, aspirin-clopidogrel combination is totally ineffective. These findings also support the concept that endothelial protection, apart from platelet inhibition, contributes to the beneficial effect of tirofiban on myocardial no-reflow.

The microorganism community in an aerobic denitrification membrane bioreactor by 16S rDNA based molecular biotechnology.

In this study, the performance and microbial community in a submerged membrane bioreactor were investigated for different hydraulic retention times. The removal efficiencies of chemical oxygen demand, total phosphorus, suspended solid and heterotrophic bacteria did not differ significantly with different hydraulic retention times but the total nitrogen removal efficiency increased when the hydraulic retention time increased. Aerobic denitrification occurred during the membrane bioreactor process at hydraulic retention time of 20 hours and Thiosphera pantotropha was identified as the aerobic denitrifier by the clone-denaturing gradient gel electrophoresis method. Another denitrifying Fe+2 oxidizing bacteria was also identified at hydraulic retention time of 20 hours. In contrast, no denitrifying bacteria were identified at hydraulic retention time of 5 hours.

The effect of residual chemical oxygen demand on anoxic and aerobic phosphate uptake and release with various intracellular polymer levels.

This study investigated the anoxic and aerobic phosphate uptake and release reactions and the fraction of denitrifying phosphate-accumulating organisms (DPAOs) under various initial chemical oxygen demand (COD) and residual COD conditions. The results showed that DPAOs and non-DPAOs could release phosphate when high soluble COD was present. Consequently, the phosphate-uptake potential was dynamic and increased when the initial COD increased, the initial polyhydroxyalkanoates (PHA) increased, and the residual COD decreased. Furthermore, the electron acceptor (oxygen of nitrate) has more significant influence on the phosphate uptake/release characteristics, while the residual COD concentrations have little influence on that. The fraction of DPAOs to phosphate-accumulating organisms was 42% when the initial PHA storage was enough by both DPAOs and non-DPAOs. This was closely related to the relative phosphate uptake (47%) in the anoxic zone of the process.

Agrobacterium tumefaciens-mediated transformation of an Oncidium orchid.

The present protocol was aimed at establishing a routine transformation procedure via Agrobacterium tumefaciens for an important Oncidium orchid cultivar. An expression vector containing hptII and gusA genes driven by the cauliflower mosaic virus (CaMV) 35S promoter was successfully introduced into the Oncidium orchid genome by A. tumefaciens. Protocorm-like bodies (PLBs) derived from protocorms, were the target explants for transformation. The transformation was performed through two stages of cocultivation, the first stage occurring on antibiotic-free medium for 3 days, and the subsequent stage on medium containing 100 mg/l timentin for 1 month. Among 1,000 inoculated PLBs, 108 putatively transformed PLBs were proliferated on 5 mg/l hygromycin selection medium. A total of 28 independent transgenic orchid plants were obtained, from which six transgenic lines that were positive for beta-glucuronidase were randomly selected and confirmed by Southern, northern and western blot analyses. These results indicated that the foreign DNA was successfully integrated into the orchid genome and expressed transcriptionally and translationally in these orchid plants. The present transformation method reported is suitable for improving the Oncidium orchid through genetic engineering.