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.

Chiari I malformation without hydrocephalus: acute intracranial hypertension managed with endoscopic third ventriculostomy (ETV)

INTRODUCTION

In a small subset of patients, a Chiari malformation can present with signs of raised intracranial pressure due to obstruction of cerebrospinal fluid flow or with the raised intracranial pressure as the primary pathological driving force resulting in tonsillar herniation.

CASE REPORT

The authors report a unique case in a 14-year-old boy with a Chiari malformation type 1-syringomyelia complex with slit-like ventricles. We have successfully managed the acute presentation of raised intracranial pressure, mimicking idiopathic intracranial hypertension, utilizing a frameless stereotactic image-navigated endoscopic third ventriculostomy alone. We present the preoperative and postoperative radiological and ophthalmological findings and discuss the possible mechanisms related to the pathophysiology and treatment in this case. The patient's symptoms resolved immediately postoperatively with resolution of papilledema. At 18-month follow-up, the patient remains entirely asymptomatic and the need for craniovertebral decompression appears to have been obviated.

CONCLUSION

We advocate that in the Chiari malformation type 1-syringomyelia complex with normal or small ventricles, patients presenting with isolated signs and symptoms of raised intracranial pressure alone can be safely and effectively managed with an electromagnetic-guided stereotactic endoscopic third ventriculostomy as a primary treatment option.

Acute bilateral anterior circulation stroke due to anomalous cerebral vasculature: a case report

INTRODUCTION

Simultaneous bilateral cerebrovascular infarction is relatively rare and its initial presentation as a space-occupying lesion is extremely uncommon. However, bilateral infarction can result from unilateral occlusion of anomalous cerebral vasculature.

CASE PRESENTATION

We report the case of a man presenting with lower limb weakness and aphasia of acute onset with initial computerised tomography suggesting bifrontal neoplasm. However, further investigation confirmed bilateral anterior cerebral artery territory infarction with a hypoplastic left anterior cerebral artery with the right anterior cerebral artery supplying both frontal lobes (an anatomical variant). We present the clinical and diagnostic features of this presentation and attempt to ascertain, by reviewing existent medical literature, the frequency and patterns of structural variations in cerebral vasculature.

CONCLUSION

Simultaneous bilateral cerebral infarction can be the result of a unilateral cerebral artery occlusion and this can potentially mimic a space-occupying lesion. Anomalies of cerebral vasculature are not as rare as is usually believed and this should be borne in mind when investigating unusual presentations of cerebrovascular infarction.

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.

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.

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.

Heterogeneity of PLAG1 gene rearrangements in pleomorphic adenoma

Pleomorphic adenoma (PA), a benign mixed salivary gland tumor, has been associated with abnormal karyotypes in up to 70% of cases, with nonrandom involvement of 8q12, the locus of the pleomorphic adenoma (PLAG1) gene. In this study, cytogenetics and fluorescence in situ hybridization (FISH) were used to investigate PLAG1 involvement in PA from seven patients. There were two males and five females ranging in age from 25 to 65 years. Samples of parotid gland tissue from the tumor sites, set up as solid tumor cultures, showed a normal karyotype in two cases [46,XY;46,XX] and cytogenetic abnormalities in five cases (71%). The abnormalities comprised one variant translocation [t(1;4;8)(p32;q35;q12)], two classic translocations [t(5;8)(p13;q12)], one novel deletion [del(12)(p11.2p12.1)], and a novel insertion [ins(9;8)(p22;q12q21.1)]. FISH was performed in all cases by using two probes from the RP11 library, flanking PLAG1; a sequence 1.48 megabases (Mb) upstream and another 2.27 Mb downstream, covering a total area of 3.8 Mb. The PLAG1 gene was intact and normally situated in four cases - the 46,XY, 46,XX, del(12p), and one t(5;8). PLAG1 was disrupted in three cases - one t(5;8), ins(9;8), and t(1;4;8). In addition, genomic instability was seen in two cases, one with PLAG1 amplification in the form of a homogeneously staining region, and the other in der(8) ring formation. The data provide further unique cases showing the complexity of PLAG1 gene rearrangements in PA.

Self-inflicted penetrating head injury in a patient with manic-depressive disorder

A 32-year-old Caucasian male with a history of repeated self-injury drilled a hole in his skull using a power tool and subsequently introduced intracerebrally a binding wire from a sketch pad. An emergency craniotomy was performed around the site of cranial injury, and the foreign body was carefully extracted. The wire was located partially in the subdural space and partially in the right hemisphere of the brain. The patient made an excellent recovery and was referred to a psychiatrist for further treatment. This is a rare case of unusual and complex repetitive self-destructive behavior without apparent suicidal intent. The pertinent literature is reviewed and the surgical and psychiatric implications of such injuries are discussed.