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Routine monitoring of inorganic arsenic in groundwater using sensitive, reliable, easy-to-use and affordable analytical methods is integral to identifying sources, and delivering appropriate remediation solutions, to the widespread global issue of arsenic pollution. Voltammetry has many advantages over other analytical techniques, but the low electroactivity of arsenic(V) requires the use of either reducing agents or relatively strong acidic conditions, which both complicate the analytical procedures, and require more complex material handling by skilled operators. Here, we present the voltammetric determination of total inorganic arsenic in conditions of near-neutral pH using a new commercially available 25 µm diameter gold microwire (called the Gold Wirebond), which is described here for the first time. The method is based on the addition of low concentrations of permanganate (10 µM MnO4-) which fulfils two roles: (1) to ensure that all inorganic arsenic is present as arsenate by chemically oxidising arsenite to arsenate and, (2) to provide a source of manganese allowing the sensitive detection of arsenate by anodic stripping voltammetry at a gold electrode. Tests were carried out in synthetic solutions of various pH (ranging from 4.7 to 9) in presence/absence of chloride. The best response was obtained in 0.25 M chloride-containing acetate buffer resulting in analytical parameters (limit of detection of 0.28 µg L-1 for 10 s deposition time, linear range up to 20 µg L-1 and a sensitivity of 63.5 nA ppb-1. s-1) better than those obtained in acidic conditions. We used this new method to measure arsenic concentrations in contrasting groundwaters: the reducing, arsenite-rich groundwaters of India (West Bengal and Bihar regions) and the oxidising, arsenate-rich groundwaters of Mexico (Guanajuato region). Very good agreement was obtained in all groundwaters with arsenic concentrations measured by inductively coupled plasma-mass spectrometry (slope = +1.029, R2 = 0.99). The voltammetric method is sensitive, faster than other voltammetric techniques for detection of arsenic (typically 10 min per sample including triplicate measurements and 2 standard additions), easier to implement than previous methods (no acidic conditions, no chemical reduction required, reproducible sensor, can be used by non-voltammetric experts) and could enable cheaper groundwater surveying campaigns with in-the-field analysis for quick data reporting, even in remote communities.
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BACKGROUND: Complete resection combined with postoperative radiotherapy is ideal for skull base chordomas. The recent literature suggests that the degree of surgical resection is the most important prognostic factor. METHODS: We retrospectively analyzed the clinical data of 16 patients with initial chordoma treated at our center between August 2015 and December 2021 and conducted a retrospective study on the prognosis of surgical treatment of skull base chordoma between 2013 and 2022. RESULTS: According to the Kaplan-Meier method, there was a significant difference in PFS between patients aged > 50 years and < 50 years, and no significant difference was observed in PFS for tumor involvement of the internal carotid artery, dura, or superior or inferior clivus. However, there was still a correlation with prognosis. As observed in the included literature, the 5-year overall survival rate was significantly higher in patients undergoing total skull base chordoma resection than in those undergoing subtotal resection (STR), which in turn was significantly higher than in those undergoing partial resection (PR). Patients undergoing subtotal resection had significantly better 5-year PFS rates than those undergoing PR. CONCLUSION: Our study shows that gross total resection and STR have better survival in patients with skull base chordomas compared to PR.
Asunto(s)
Cordoma , Neoplasias de la Base del Cráneo , Cordoma/cirugía , Estudios de Seguimiento , Humanos , Pronóstico , Estudios Retrospectivos , Base del Cráneo/patología , Neoplasias de la Base del Cráneo/patología , Neoplasias de la Base del Cráneo/radioterapia , Neoplasias de la Base del Cráneo/cirugía , Resultado del TratamientoRESUMEN
ABSTRACT Purpose Various surgical options are available for large proximal ureteral stones, such as extracorporeal shock wave lithotripsy (ESWL), ureteroscopic lithotripsy (URSL), percutaneous nephrolithotomy (PCNL) and laparoscopic ureterolithotomy (LU). However, the best option remains controversial. Therefore, we conducted a network meta-analysis comparing various surgical treatments for proximal ureteral stones ≥10mm to address current research deficiencies. Materials and methods We searched PubMed, Ovid, Scopus (up to June 2019), as well as citation lists to identify eligible comparative studies. All clinical studies including patients comparing surgical treatments for proximal ureteral stones ≥10mm were included. A standard network meta-analysis was performed with Stata SE 14 (Stata Corp, College Station, TX, USA) software to generate comparative statistics. The quality was assessed with level of evidence according to the Oxford Centre for Evidence-based Medicine and risk of bias with the Cochrane Collaboration's Review Manager (RevMan) 5.3 software. Results A total of 25 studies including 2.888 patients were included in this network meta-analysis. Network meta-analyses indicated that LU and PCNL had better stone-free rates and auxiliary procedures. PCNL could result in major complications and severe bleeding. In initial stone-free rate, final stone-free rate, and auxiliary procedures results, SUCRA ranking was: LU> PCNL> URSL> ESWL. In Clavien Dindo score ≥3 complications, SUCRA ranking was: LU> ESWL> URSL> PCNL. In fever, SUCRA ranking was: ESWL> LU> URSL> PCNL. In transfusion, SUCRA ranking was: LU> URSL> ESWL> PCNL. In Cluster analysis, LU had the highest advantages and acceptable side effects. Considering the traumatic nature of PCNL, it should not be an option over URSL. ESWL had the lowest advantages. Conclusions LU have the potential to be considered as the first treatment choice of proximal ureteral stone ≥10mm.
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Humanos , Masculino , Cálculos Ureterales/cirugía , Litotricia , Resultado del Tratamiento , Ureteroscopía , Metaanálisis en Red , Nefrolitotomía Percutánea/efectos adversosRESUMEN
PURPOSE: Various surgical options are available for large proximal ureteral stones, such as extracorporeal shock wave lithotripsy (ESWL), ureteroscopic lithotripsy (URSL), percutaneous nephrolithotomy (PCNL) and laparoscopic ureterolithotomy (LU). However, the best option remains controversial. Therefore, we conducted a network meta-analysis comparing various surgical treatments for proximal ureteral stones ≥10mm to address current research deficiencies. MATERIALS AND METHODS: We searched PubMed, Ovid, Scopus (up to June 2019), as well as citation lists to identify eligible comparative studies. All clinical studies including patients comparing surgical treatments for proximal ureteral stones ≥10mm were included. A standard network meta-analysis was performed with Stata SE 14 (Stata Corp, College Station, TX, USA) software to generate comparative statistics. The quality was assessed with level of evidence according to the Oxford Centre for Evidence-based Medicine and risk of bias with the Cochrane Collaboration's Review Manager (RevMan) 5.3 software. RESULTS: A total of 25 studies including 2.888 patients were included in this network meta-analysis. Network meta-analyses indicated that LU and PCNL had better stone-free rates and auxiliary procedures. PCNL could result in major complications and severe bleeding. In initial stone-free rate, final stone-free rate, and auxiliary procedures results, SUCRA ranking was: LU> PCNL> URSL> ESWL. In Clavien Dindo score ≥3 complications, SUCRA ranking was: LU> ESWL> URSL> PCNL. In fever, SUCRA ranking was: ESWL> LU> URSL> PCNL. In transfusion, SUCRA ranking was: LU> URSL> ESWL> PCNL. In Cluster analysis, LU had the highest advantages and acceptable side effects. Considering the traumatic nature of PCNL, it should not be an option over URSL. ESWL had the lowest advantages. CONCLUSIONS: LU have the potential to be considered as the first treatment choice of proximal ureteral stone ≥10mm.