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Lead and zinc mines are a primary source of environmental (post)-transition metal contamination resulting in major water pollution. In this study, the use of biochar amended with wood ash (WAS) was evaluated as a method to remediate zinc and lead contaminated mine water. Water from Nantymwyn lead mine, with zinc and lead concentrations as high as 12.1 mg/L and 1.7 mg/L respectively was used. The contact time for WAS to immobilise zinc and lead (1 min to 24 h), immobilisation mechanisms and maximum measured removal of lead and zinc were studied. FTIR spectroscopy and XPS was used to characterise WAS and the aqueous modelling program PHREEQC (pH redox equilibrium) was used to analyse mine water speciation. The fast removal performance of a biochar is a key indicator of its viability to be used as a green remediator. If the required contact time to remediate contaminated water is too long the sorbent becomes impractical. This study demonstrated that WAS removed 97% of zinc and 86% of lead within the first minute of contact with the mine water (0.5 g of WAS per 20 mL of mine water), with a maximum measured removal of 14.8 mg/g for zinc and 23.7 mg/g for lead (using 0.1g – 0.002 g of WAS per 40 mL of mine water). Fast removal was primarily a result of precipitation, and subsequent capture by WAS, and ion exchange. These findings show that WAS has the potential to be scaled up and deployed at mine sites to remediate contaminated water.

The exponential growth in the use of motor vehicles is a key contributor to freshwater degradation. Current remediation techniques require prohibitively expensive contaminant treatment and extraction. Biochar represents an inexpensive option to ameliorate contaminants from motorway runoff. Biochar from Norway spruce (Picea abies (L.) Karst.) was produced under fast pyrolysis-gasification (450–500 °C for 90 s) and amended with wood ash and basaltic rock dust to evaluate sorption of Pb, Cu, Zn and Cd. The column study, designed to mimic field conditions, confirmed that unamended biochar can bind contaminants for short periods, but that the addition of amendments, particularly wood ash, significantly improves contaminant removal. Wood ash-amended biochar removed 98–100% of all contaminants during the study, driven by pH (r = 0.73–0.74; p

The pollution of aqueous environments by metals has continued to increase due to anthropogenic activities such as mining, waste disposal, industrial activities and the use of motor vehicles.

Correction for ‘Treatment of mine water for the fast removal of zinc and lead by wood ash amended biochar’ by Stuart Cairns et al., Environ. Sci.: Adv., 2022, 1, 506–516, https://doi.org/10.1039/d2va00085g.

Heavy metals in motorway adjoined aqueous environments have increased at an alarming rate over recent years. This increase has been primarily attributed to anthropogenic activities such as the increase of motor vehicle use. Current remediation techniques, such as balancing ponds have the potential to leave toxic residue with the associated removal costs often proving prohibitive. In this study biochar and wood ash amended biochar were evaluated as remediators of inorganic vehicular pollutants found in motorway runoff, specifically Pb, Cu, Zn and Cd. Biochar from European larch (Larix decidua (L.) Karst.) was produced via fast pyrolysis-gasification (485–530 °C for 90 s) and amended with wood ash post pyrolysis. Pristine larch biochar (BC), larch biochar cold mixed with wood ash (WA) and larch biochar sintered with wood ash (WAS) were studied to evaluate metal immobilisation mechanisms and maximum removal capacities. This study demonstrates that the amendment of biochar with wood ash increases Pb, Cu, Zn, and Cd immobilisation by an order of magnitude compared to BC. The addition of wood ash increases pH whilst adding minerals causing precipitation. Precipitation and ion exchange dominate metal immobilisation and were not correlated to surface area. Sustainability of feedstock, low feedstock/production costs and maximum measured contaminant removal (61.5 mg/g, 38.9 mg/g, 12.1 mg/g and 10.2 mg/g for Pb, Cu, Zn and Cd respectively) indicate that wood ash amended biochar is a viable option to immobilise Pb, Cu, Zn and Cd from motorway runoff.

The high sensitivity of proton transfer reaction-mass spectrometry (PTR-MS) makes it a suitable analytical tool for detecting trace compounds. Its specificity is primarily determined by the accuracy of identifying the m/ z of the product ions specific to a particular compound. However, specificity can be enhanced by changing the product ions (concentrations and types) through modifying the reduced electric field. For current PTR-MS systems, this is not possible for trace compounds that would only be present in the reaction chamber of a PTR-MS for a short time (seconds). For such circumstances, it is necessary to change the reduce electric field swiftly if specificity enhancements are to be achieved. In this paper we demonstrate such a novel approach, which permits any compound that may only be present in the drift tube for seconds to be thoroughly investigated. Specifically, we have developed hardware and software which permits the reaction region's voltages to be rapidly switched at a frequency of 0.1-5 Hz. We show how this technique can be used to provide a higher confidence in the identification of compounds than is possible by keeping to one reduced electric field value through illustrating the detection of explosives. Although demonstrated for homeland security applications, this new technique has applications in other analytical areas and disciplines where rapid changes in a compound's concentration can occur, for example, in the Earth's atmosphere, plant emissions and in breath. Importantly, this adaptation provides a method for improved selectivity without expensive instrumental changes or the need for high mass resolution instruments.

BACKGROUND: Though possession of androgenic anabolic steroids (AAS) is illegal, non-prescription use of AAS persists. METHODS: We describe two Caucasian males (aged 25 and 45 years) with cholestatic hepatitis following ingestion of the dietary supplement Mass-Drol ('Celtic Dragon') containing the AAS 2α-17α-dimethyl-etiocholan-3-one,17β-ol. RESULTS: Despite substantial hyperbilirubinaemia peak gamma-glutamyl transferase (GGT) remained normal. Besides 'bland' intralobular cholestasis, liver biopsy in both found deficiency of canalicular expression of ectoenzymes as seen in ATP8B1 disease. In the older patient, bile salt export pump marking (encoded by ABCB11) was focally diminished. We hypothesized that AAS had either induced inhibition of normal ATP8B1/ABCB11 expression or triggered initial episodes of benign recurrent intrahepatic cholestasis (BRIC) type 1/or 2. On sequencing, ATP8B1 was normal in both patients although the younger was heterozygous for the c.2093G>A mutation in ABCB11, a polymorphism previously encountered in drug-induced liver injury. CONCLUSION: AAS marketed as dietary supplements continue to cause hepatotoxicity in the UK; underlying mechanisms may include unmasking of genetic cholestatic syndromes.

A key issue with any analytical system based on mass spectrometry with no initial separation of compounds is to have a high level of confidence in chemical assignment. This is particularly true for areas of security, such as airports, and recent terrorist attacks have highlighted the need for reliable analytical instrumentation. Proton transfer reaction mass spectrometry is a useful technology for these purposes because the chances of false positives are small owing to the use of a mass spectrometric analysis. However, the detection of an ion at a given m/z for an explosive does not guarantee that that explosive is present. There is still some ambiguity associated with any chemical assignment owing to the presence of isobaric compounds and, depending on mass resolution, ions with the same nominal m/z. In this article we describe how for the first time the use of a radio frequency ion-funnel (RFIF) in the reaction region (drift tube) of a proton transfer reaction−time-offlight− mass spectrometer (PTR-ToF-MS) can be used to enhance specificity by manipulating the ion−molecule chemistry through collisional induced processes. Results for trinitrotoluene, dinitrotoluenes, and nitrotoluenes are presented to demonstrate the advantages of this new RFIF-PTR-ToF-MS for analytical chemical purposes

Please refer to fig 1 for an algorithmic representation of the recommendations, and tables 1–3 for a risk stratification of endoscopic procedures and medical conditions requiring anticoagulant or antiplatelet therapy. Aspirin therapy can be continued for all endoscopic procedures. Figure 1 Guidelines for the management of patients on warfarin or clopidogrel undergoing endoscopic procedures. AF, atrial fibrillation; EMR, endoscopic mucosal resection; ERCP, endoscopic retrograde cholangiopancreatography; EUS, endoscopic ultrasound; FNA, fine needle aspiration; INR, international normalised ratio; LMWH, low molecular weight heparin; PEG, percutaneous endoscopic gastroenterostomy; VTE, venous thromboembolism. View this table: Table 1 Risk stratification of endoscopic procedures based on risk of haemorrhage View this table: Table 2 Risk stratification for discontinuation of anticoagulant therapy View this table: Table 3 Risk stratification for discontinuation of clopidogrel ### 1.1 Acute gastro-intestinal haemorrhage Acute gastro-intestinal haemorrhage in patients on anticoagulant or antiplatelet agents is a high-risk situation. The immediate risk to the patient from haemorrhage may outweigh the risk of thrombosis as a result of stopping anticoagulant or antiplatelet therapy. Patients need to be assessed on an individual basis, and it is not possible to give unequivocal guidance to cover all situations. For patients with high-risk conditions on warfarin, then this can be discontinued with or without substitution of heparin depending on the severity of haemorrhage and risk of discontinuing anticoagulant therapy. There is a high risk of acute myocardial infarction or death if clopidogrel is discontinued in patients with coronary stents, particularly early after implantation, but extending up to 1 year after this. Endoscopy should be attempted as soon as safely possible after urgent liaison between the patient’s cardiologist and the consultant specialist undertaking endoscopy. Clopidogrel should not be discontinued without discussion with a cardiologist. If clopidogrel therapy needs to be discontinued in this context, then this should be limited to a maximum of 5 days as the risk of stent thrombosis increases after this interval. (Evidence grade III. Recommendation grade B.) Early therapeutic endoscopic intervention may achieve haemostasis with minimal or no cessation of anticoagulant or antiplatelet therapy, and should be the first aim. (Evidence grade IV. Recommendation grade C.) ### 1.2 Low-risk endoscopic procedures Anticoagulation or antiplatelet therapy should be continued. (Evidence grade IV. Recommendation grade C.) If warfarin is continued then it should be ensured that the international normalised ratio (INR) does not exceed the therapeutic range: (Evidence grade IV. Recommendation grade C.)

After a short period as a general practitioner, Robert John Cairns developed a special interest in dermatology and trained at St John’s Hospital and St Mary’s Hospital in London. He served as a dermatologist on a short service commission in the Royal Army Medical Corps and was posted to Germany, to military hospitals in …

The activities of hybrid dimers of alkaline phosphatase containing two chemically modified subunits have been investigated. One hybrid species was prepared by dissociation and reconstitution of a mixture of two variants produced by chemical modification of the native enzyme with succinic anhydride and tetranitromethane, respectively. The succinyl-nitrotyrosyl hybrid was separated from the other members of the hybrid set by DEAE-Sephadex chromatography and then converted to a succinyl-aminotyrosyl hybrid by reduction of the modified tyrosine residues with sodium dithionite. A comparison of the activities of these two hybrids with the activities of the succinyl, nitrotyrosyl and aminotyrosyl derivatives has shown that either the subunits of alkaline phosphatase function independently or if the subunits turnover alternately in a reciprocating mechanism, then the intrinsic activity of each subunit must be strongly dependent on its partner subunit.

Key learning points ‘Cocoon syndrome’ is a possible differential in patients with end-stage cirrhosis who present with vomiting and abdominal symptoms. Recurrent inflammation of the peritoneum from spontaneous bacterial peritonitis (SBP) leads to encasement of the bowel. Computed

The British Society of Gastroenterology (BSG) and the Association of Coloproctology for Great Britain and Ireland (ACPGBI) commissioned these guidelines. The aim is to provide guidance on the appropriateness, method, and frequency of screening people with diseases known to be associated with colorectal cancer. There is increasing awareness among relatives of patients with colorectal cancer that they may be at risk from this disease and there is rising demand for screening. These guidelines are for members of gastroenterology teams, primary care physicians, purchasers of health care, and people thought to be at increased risk of colorectal cancer.

The management of hilar strictures is dependent upon their resectability and may therefore require a multidisciplinary approach. However, resectability rates for such tumors are reported to be in the region of 15%–20%, and, therefore, palliative therapy will be the mainstay of treatment for most patients. With the presenting symptoms being those of obstructive jaundice and the consequences of cholestasis, a significant improvement in morbidity can be obtained by achieving biliary drainage. A number of options are available, including the placement of Teflon or expandable metallic endoprostheses by either the endoscopic or percutaneous route. Some considerable debate exists as to which route of stent placement is best, and in many circumstances the decision will depend on the availability of local services. Some have suggested that success rates with percutaneous stenting are superior to those for endoscopic placement, but the latter technique may be associated with fewer complications. In competent hands, endoscopic placement does achieve a high rate of success and it should be remembered that a combined approach may further improve success rates. The debate over the use of plastic versus metallic stents is centered around the higher rates of stent occlusion/migration for plastic stents seen in some studies, although a stent change is usually possible. An additional advantage of metallic stents is that they may provide drainage of the side branches of the biliary tree through the mesh. However, possible drawbacks may be a greater difficulty in placement of a second stent where a first provides inadequate drainage, and cost issues often have to be taken into consideration. Considerable debate exists over the optimum number of stents required to achieve adequate drainage and minimize the risks of cholangitis. There is good evidence that if overfilling of the biliary tree with contrast is avoided with only the segments to be drained visualized, a single stent may be all that is required, while others argue that placement of more than one stent may improve survival. In the following review we discuss these issues, and conclude by considering success rates and complications following endoprosthesis insertion; we also discuss the prognosis of patients treated in this way.