Clinical deterioration despite syringomyelia resolution after successful foramen magnum decompression for Chiari malformation - Case series.

INTRODUCTION: Neurosurgical treatment is recommended for symptomatic syringomyelia and the post-operative radiological resolution of the syringomyelia is associated with an improvement or at least stability of the patient's pre-operative symptoms. METHODS: We reviewed syringomyelia treatment in our centre over the last five years for clinical outcome, surgical complications, post operative MRI and long term symptom resolution. RESULTS: 50 cases of symptomatic syringomyelia underwent foramen magnum decompression and expansile watertight duroplasty. While the outcomes for majority are similar to what published in literature, three of them developed typical syringomyelia symptoms after initial good recovery and radiological resolution of syrinx. CONCLUSION: Syringomyelia symptoms may appear or worsen following successful surgical treatment and radiological resolution of syrinx and it is important to counsel young people and their family regarding this.

Autobiographical memory loss following a right prefrontal lobe tumour resection: a case report and review of the literature.

INTRODUCTION: The right prefrontal lobe has not traditionally been considered eloquent brain. Resection of tumours within this region does not typically lead to permanent functional impairment. In this report, we highlight the case of a patient who developed autobiographical memory loss following an uncomplicated resection of a right prefrontal tumour. CASE MATERIAL: A previously fit and well 15-year old presented with a persistent right-sided headache. An MRI demonstrated an expanded right mid-frontal gyrus with changes consistent with a low-grade tumour. The patient underwent a right-sided craniotomy and resection of the lesion which was confirmed as a WHO grade II diffuse astrocytoma. Postoperatively, the patient reported profound retrograde amnesia for a range of memory components, in particular autobiographical memory and semantic memory. Postoperative imaging showed a good resection margin with no evidence of underlying brain injury. Over an 18-month period, the patient showed no improvement in autobiographical memory; however, significant relearning of semantic knowledge took place and her academic performance was found to be in line with expectations for her age. CONCLUSION: In this report, we discuss a case and review the literature on the role of the right prefrontal cortex in memory and caution on the perception of right prefrontal non-eloquence.

Phosphate adsorption from wastewater using zirconium (IV) hydroxide: Kinetics, thermodynamics and membrane filtration adsorption hybrid system studies.

Excessive phosphate in wastewater should be removed to control eutrophication of water bodies. The potential of employing amorphous zirconium (Zr) hydroxide to remove phosphate from synthetic wastewater was studied in batch adsorption experiments and in a submerged membrane filtration adsorption hybrid (MFAH) reactor. The adsorption data satisfactorily fitted to Langmuir, pseudo-first order and pseudo-second order models. Langmuir adsorption maxima at 22 °C and pHs of 4.0, 7.1, and 10.0 were 30.40, 18.50, and 19.60 mg P/g, respectively. At pH 7.1 and temperatures of 40 °C and 60 °C, they were 43.80 and 54.60 mg P/g, respectively. The thermodynamic parameters, ΔG° and ΔS° were negative and ΔH° was positive. FTIR, zeta potential and competitive phosphate, sulphate and nitrate adsorption data showed that the mechanism of phosphate adsorption was inner-sphere complexation. In the submerged MFAH reactor experiment, when Zr hydroxide was added at doses of 1-5 g/L once only at the start of the experiment, the removal of phosphate from 3 L of wastewater containing 10 mg P/L declined after 5 h of operation. However, when Zr hydroxide was repeatedly added at 5 g/L dose every 24 h, satisfactory removal of phosphate was maintained for 3 days.

Adsorptive removal of heavy metals from water using sodium titanate nanofibres loaded onto GAC in fixed-bed columns.

Heavy metals are serious pollutants in aquatic environments. A study was undertaken to remove Cu, Cd, Ni, Pb and Zn individually (single metal system) and together (mixed metals system) from water by adsorption onto a sodium titanate nanofibrous material. Langmuir adsorption capacities (mg/g) at 10(-3)M NaNO3 ionic strength in the single metal system were 60, 83, 115 and 149 for Ni, Zn, Cu, and Cd, respectively, at pH 6.5 and 250 for Pb at pH 4.0. In the mixed metals system they decreased at high metals concentrations. In column experiments with 4% titanate material and 96% granular activated carbon (w/w) mixture at pH 5.0, the metals breakthrough times and adsorption capacities (for both single and mixed metals systems) decreased in the order Pb>Cd, Cu>Zn>Ni within 266 bed volumes. The amounts adsorbed were up to 82 times higher depending on the metal in the granular activated carbon+titanate column than in the granular activated carbon column. The study showed that the titanate material has high potential for removing heavy metals from polluted water when used with granular activated carbon at a very low proportion in fixed-bed columns.

Spinal dural arteriovenous fistulas--presentation, management and outcome in a single neurosurgical institution.

OBJECTIVE: To compare the outcome, with respect to treatment modality, of patients treated with spinal dural arteriovenous fistulas (SDAVF). METHOD: Retrospective cohort study of patients with SDAVF assessed at a single tertiary referral centre, between 1999 and 2009. Intervention type, pre-/ post-intervention Aminoff-Logue disability score (ALDS) and recurrence rate were obtained from medical records. RESULTS: 26 patients were identified with 23 receiving intervention. All patients initially received super selective angiogram, with 13 undergoing endovascular embolization at this stage, after discussion between the surgeon and interventional radiologist. Six patients who underwent embolization had a recurrence. The remaining 10 patients had fistulas marked during angiography, and were then treated surgically, after discussion. One of these recurred. The difference in recurrence rate between the two intervention types was not statistically significant. Fistulas treated with the embolization material onyx were twice as likely to recur as those treated with the alternative material, histoacryl-lipiodol. There was a statistically significant difference between the modes of intervention in relation to clinical outcome. Surgeries lead to an improvement in neurology, whereas treatment via embolization did not. Neurological improvement was seen in non-recurring cases, however deterioration in neurological function occurred with fistula recurrence. CONCLUSION: Super selective angiography is effective in defining the relevant vascular anatomy and allows for precise fistula localization during any potential subsequent surgery. Onyx was associated with a higher recurrence rate, suggesting it is less suitable as an embolization material for SDAVF treatment. Surgery appeared to correlate to reversal of neurological impairment seen at presentation, possibly due to a lower recurrence rate. The study is limited by small patient numbers, emphasizing the need for further studies of SDAVF patients.

Performance of submerged membrane bioreactor (SMBR) with and without the addition of the different particle sizes of GAC as suspended medium.

In this study the effect of different particle sizes of granular activated carbon (GAC) on the performance of a submerged membrane bioreactor (SMBR) was investigated. The sizes of GAC used were 150-300, 300-600 and 600-1200 µm. The SMBR was operated at a filtration flux of 20 L/m(2)h. The removal of dissolved organic carbon (DOC) and chemical oxygen demand (COD) with the addition of GAC was 95%. The concentration of biopolymers, humic, building block and low molecular weight neutral and acids in the SMBR effluent was reduced by 20%, 66-76%, 20-50%, 30-56%, respectively. It helped to reduce the sludge volume index (SVI) and transmembrane pressure (TMP) development by 30-40% and 58%, respectively. However, the removal of NH4(+) and PO4(3-) was relatively low of 35-45% and 34-43%, respectively. The SMBR effluent was rich in PO4(3-) and was removed/recovered using hydrated ferric oxide (HFO). The removal of PO4(3-) was almost 90%.

Effect of imposed flux on fouling behavior in high rate membrane bioreactor.

The influence of imposed flux and aeration rates on membrane fouling in a submerged membrane bioreactor was studied. The experiments were conducted at four imposed fluxes and three aeration rates. The effect of flux on the reduction of membrane fouling was much higher than that caused by aeration rate. A lower flux of 20 L/m(2) h produced 75 times more water than a higher flux of 40 L/m(2) h with an aeration rate of 2 L/min. Low flux showed slightly higher removal of NH(4)-N and 93-96% removal of dissolved organic matter and chemical oxygen demand. Imposed flux also had a significant effect on the composition of organics present in the soluble microbial product (SMP) and extracellular polymeric substances (EPS). At a higher flux, both SMP and EPS had organics of high molecular weight (MW) of around 48 kDa as well as lower MW organics below 200 Da.

Effect of organic loading rate on organic matter and foulant characteristics in membrane bio-reactor.

In this study, the influence of organic loading rate (OLR) on the performance of a membrane bio-reactor (MBR) was investigated. The MBR was operated with 6 different OLRs between 0.5 and 3.0 kg COD/m(3)d. The hydrodynamic parameters of the MBR were kept constant. The hydraulic retention time and sludge retention time were kept at 8h and 40 d respectively. From the experimental investigation, it was found that the removal efficiency of DOC, COD and NH(4)-N decreased when OLRs were increased from 0.5 to 3.0 kg COD/m(3)d. Higher OLRs of 2.75-3.0 kg COD/m(3)d resulted in a higher transmembrane pressure development. The fractionation of organic matters showed more hydrophilic substances with higher OLRs. A detailed organic matter characterization of membrane foulant, soluble microbial product and extracellular polymeric substances showed that bio-polymers type substances together with humic acid and lower molecular neutral and acids were responsible for membrane fouling.

Biofiltration as pre-treatment to water harvesting and recycling.

This paper presents the results of the long term biofilter experiments conducted with raw stormwater collected from a canal at Carlton, in Sydney. Anthracite and granular activated carbon (GAC) were used as a single filter media in biofilter columns. Media heights of 75 and 40 cm were used. The filter columns were operated at filtration velocities of 0.12 and 0.25 m/h. The removal efficiency for turbidity and DOC for the GAC filter media were found to be 75% and almost 100% respectively. The removal efficiency for the anthracite filter was much lower. Molecular weight distribution analysis showed an almost similar trend to the DOC removal. Compared with anthracite filter media, the GAC biofilter removed a much larger range of organic compounds present in the stormwater. The GAC biofilter removes organic matter earlier as compared to anthracite. Based on a limited sample of stormwater, the removal efficiency for phosphorus was upto 74% and that of nitrogen was up to 30%. In general GAC filter shows higher heavy metal removal efficiency than anthracite. The removal of zinc, iron, lead and nickel were good. However the concentration of heavy metal in the raw surface water sample was low.

Valuing stormwater, rainwater and wastewater in the soft path for water management: Australian case studies.

A Water Sensitive City is now commonly acknowledged best practice for designing the cities of the future. In Australia, the National Water Initiative has allocated high priority towards offering insight into successful water sensitive urban development projects, to facilitate capacity building within the industry. This paper shares innovative water sensitive projects implemented at Kogarah City Council, in Sydney. Four key projects are discussed, demonstrating how stormwater, rainwater and wastewater can be incorporated into decentralised water systems to offer sustainable water management of the future. The case studies included in the paper highlight Kogarah's journey towards the Soft Path for Water Management.

Hybrid filtration method for pre-treatment of stormwater.

In this study the hybrid filtration process (combining fibre filter with deep bed dual media filtration) was investigated as pre-treatment to stormwater. This process was investigated in-terms of reduction in turbidity, dissolved organic carbon (DOC), colour, headloss development across the filters, suspended solids removal, organic matter removal, nutrients and heavy matter (such as iron, copper, lead, zinc) removal efficiency. A comparison was made between the hybrid filter with single media (sand) deep bed filter and fibre filter. It was found that the hybrid filtration system successfully removed turbidity (98%), colour (99%), suspended solids (99%), and DOC (55%). The removal efficiency of heavy metal was relatively low as the concentration of heavy metals present in stormwater was low. The removal efficiency of nitrate, nitrite and phosphorous (as orthophosphate) was 27, 35 and 72% respectively. Hybrid filtration processes showed a better reduction of Modified Fouling Index (MFI) value (from 15.500 s/l(2) to 9 s/l(2)) compared with single media sand, anthracite and fibre filter which were 35 s/l(2), 13 s/l(2)and 14 s/l(2) respectively when operated at FeCl(3) dose of 15 mg/l.

Preparation of titanium dioxide nanoparticles from electrocoagulated sludge using sacrificial titanium electrodes.

A comprehensive investigation of electrocoagulation using sacrificial titanium (Ti) electrodes in wastewater was carried out. The effects of specific process variables, such as initial pH, mixing, current density, initial organic loading, and ionic/electrolyte strength were first optimized to produce recyclable Ti-based sludge. The sludge was incinerated at 600 degrees C to produce functional TiO(2) photocatalyst. X-ray diffraction analysis revealed that TiO(2) produced at optimum electrocoagulation conditions was mostly anatase structure. The specific surface area of the synthesized TiO(2) photocatalyst was higher than that of the commercially available and widely used Degussa P-25 TiO(2). Furthermore, energy dispersive X-ray and X-ray photoelectron spectroscopy analyses showed that in additional to titanium and oxygen, this photocatalyst is also composed of carbon and phosphorus. These elements were mainly doped as a substitute site for the oxygen atom. Transmission electron microscopy images exhibited sharply edged nanorods, round nanoparticles, and nanotubes with nonuniform shapes showing some structural defects. Photodecomposition of gaseous acetaldehyde by this photocatalyst was also conducted under UV and visible light irradiation to study the photocatalytic properties of the doped TiO(2) photocatalyst. While no photocatalytic activity was observed under visible light irradiation, this doped TiO(2) photocatalyst exhibited high photocatalytic activity under UV light.

Analysis of first flush to improve the water quality in rainwater tanks.

Although most Australians receive their domestic supply from reticulated mains or town water, there are vast areas with very low population densities and few reticulated supplies. In many of these areas rainwater collected in tanks is the primary source of drinking water. Heavy metals have recently become a concern as their concentration in rain water tanks was found to exceed recommended levels suitable for human consumption. Rainwater storage tanks also accumulate contaminants and sediments that settle to the bottom. Although not widely acknowledged, small amounts of contaminants such as lead found in rain water (used as drinking water) may have a cumulative and poisonous effect on human health over a life time. This is true for certain factors that underlie many of the chronic illnesses that are becoming increasingly common in contemporary society. The paper reports on a study which is part of a project that aims to develop a cost effective in-line filtration system to improve water quality in rainwater tanks. To enable this, the characteristics of rainwater need to be known. One component of this characterization is to observe the effects of the first flush on a rainwater tank. Samples of the roof runoff collected from an urban residential roof located in the Sydney Metropolitan Area in the initial first few millimetres of rain were analysed. The results show that bypassing the first 2 mm of rainfall gives water with most water quality parameters compliant with the Australian Drinking Water Guidelines (ADWG) standards. The parameters that did not comply were lead and turbidity, which required bypassing approximately the first 5 mm of rainfall to meet ADWG standards. Molecular weight distribution (MWD) analysis showed that the concentration of rainwater organic matter (RWOM) decreased with increasing amount of roof runoff.

Membranes coupled with physico chemical treatment in water reuse.

In this study, short-term experiments were conducted with different configurations of membrane hybrid systems to treat biological treated sewage effluent containing refractory organic pollutants: (i) submerged hollow fiber microfiltration (SMF) alone; (ii) spiral flocculator (SF)-SMF without settling; (iii) SF-PAC-SMF without settling and (iv) SMF with magnetic ion exchange resin MIEX pretreatment. The results indicated that the pre-flocculation of SF could improve the mitigation of membrane fouling significantly even when the system was operated at a high membrane filtration rate. The transmembrane pressure (TMP) of SF-PAC-SMF only increased marginally (0.8 kPa over 8 hours). SF-SMF without the addition of powdered activated carbon (PAC) also took a relatively long duration for the TMP to increase. The TMP only increased by 2.5 kPa over 8 hours. The SF-PAC-MF system resulted in a high dissolved organic carbon (DOC) removal of more than 96%. When used as pre-treatment to submerged membranes, the fluidized bed MIEX contactor could remove a significant amount of organic matter in wastewater. This pre-treatment helped to reduce the membrane fouling and kept the TMP low during the membrane operation.

Adsorption and removal of arsenic from water by iron ore mining waste.

There is a global need to develop low-cost technologies to remove arsenic from water for individual household water supply. In this study, a purified and enriched waste material (treated magnetite waste, TMW) from the Trai Cau's iron ore mine in the Thai Nguyen Province in Vietnam was examined for its capacity to remove arsenic. The treatment system was packed with TMW that consisted of 75% of ferrous-ferric oxide (Fe(3)O(4)) and had a large surface area of 89.7 m(2)/g. The experiments were conducted at a filtration rate of 0.05 m/h to treat groundwater with an arsenic concentration of 380 microg/L and iron, manganese and phosphate concentrations of 2.07 mg/L, 0.093 mg/L and 1.6 mg/L respectively. The batch experimental results show that this new material was able to absorb up to 0.74 mg arsenic/g. The results also indicated that the treatment system removed more than 90% arsenic giving an effluent with an arsenic concentration of less than 30 microg/L while achieving a removal efficiency of about 80% for Mn(2 + ) and PO(4) (3-). This could be a promising and cost-effective new material for capturing arsenic as well as other metals from groundwater.

Membrane fouling propensity after adsorption as pretreatment in rainwater: a detailed organic characterisation.

Organic characterisation in rainwater was investigated in terms of dissolved organic carbon (DOC) and molecular weight distribution (MWD) after powdered activated carbon (PAC) adsorption. PAC adsorption was used as pretreatment to membrane filtration to reduce membrane fouling. The MW of organic matter in rainwater used in this study was in the range of 43,000 Da to 30 Da. Each peak of organic matter consisted of biopolymers (polysaccharides and proteins), humic and fulvic acids, building blocks, low MW acids (hydrolysates of humic substances), low MW neutrals and amphiphilics. Rainwater contained the majority of hydrophilic compounds up to 72%. PAC adsorption removed 33% of total DOC. The removal efficiencies of the hydrophobic and hydrophilic fractions after PAC adsorption were 50% and 27%, respectively. PAC adsorption was found to preferentially remove the hydrophobic fraction. The majority of the smaller MW of 1,100 Da, 820 Da, 550 Da, 90 Da and 30 Da was removed after PAC adsorption. The MFI values decreased from 1,436 s/L2 to 147 s/L2 after PAC adsorption. It was concluded that PAC adsorption can be used as a pretreatment to membrane filtration with rainwater.

Primary Nocardia farcinica brain abscess with secondary meningitis and ventriculitis in an immunocompetent patient, successfully treated with moxifloxacin.

We report a rare case of Nocardia farcinica occipital brain abscess in an immunocompetent patient with no underlying risk factors successfully treated with the antibiotic moxifloxacin. The patient underwent craniotomy and abscess drainage. Initial post-operative treatment with co-trimoxazole produced a limited response. Despite the development of skull base meningitis and ventriculitis subsequent addition of moxifloxacin produced an excellent outcome.

Dysphagia and hoarse voice: an unusual cause.

We report an unusual presentation and successful treatment of an extracranial skull base carotid aneurysm. The patient presented with a combination of multiple cranial nerve dysfunction and local mass effect. After endovascular treatment of this rare condition her symptoms resolved. The radiological images submitted demonstrate this rare condition well.

Relief of severe retro-orbital pain and vision improvement after optic-nerve decompression in polyostotic fibrous dysplasia: case report and review of the literature.

INTRODUCTION: We describe a case of a 9-year-old girl who developed progressive severe retro-orbital pain and partial visual loss in association with left optic-nerve compression due to polyostotic fibrous dysplasia of the skull. MATERIALS AND METHODS: Intradural decompression of the optic nerve resulted in immediate and complete resolution of the pain as well as a vast visual improvement. CONCLUSION: In cases of fibrous dysplasia of the skull with evidence of optic-nerve compression, relief of retro-orbital pain should be an additional consideration when deciding to proceed with surgical management.