13 research outputs found

    Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

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    Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

    Electrochemical biosensor for sensitive quantification of glyphosate in maize kernels

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    "A graphite-epoxy electrode (GE) modified with multiwalled carbon nanotubes (MWCNTs) and horseradish peroxidase (GE/MWCNTs-HRP) was used to build a glyphosate biosensor whose performance in aqueous solutions depends on the enzyme activity. For the biosensor preparation, MWCNTs were deposited onto the GE surface by electrophoresis using an oxidative treatment (H2SO4/HNO3) in presence of cetyl tributylammonium bromide (CTAB) as a cationic surfactant. The surfactant was further removed from the MWCNTs surface by dipping the electrode in an EtOH/HCl solution. The physical immobilization of HRP and therefore the glyphosate sensing capabilities was tested at pH 4 where the herbicide exhibits one only species. Circular dichroism studies suggested that the secondary structure of HRP changes as a result of its interaction with glyphosate and that this change is intensified by the combination of glyphosate and H2O2, which may explain the decrease of the enzyme catalytic activity with the increase of glyphosate concentration. The glyphosate quantification in doped-maize kernels was highly reproducible and exhibits detection and quantification limits of 1.32 pM and 1.63 pM respectively. The biosensor is also characterized by a high recovery (100 %) and precision (coefficient of variation <1 %) and can be employed in presence of interfering substances such as chlorpyrifos (an organophosphate pesticide) and starch"

    Indirect quantification of glyphosate by SERS Using an incubation process with hemin as the reporter molecule: a contribution to signal amplification mechanism

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    "The indirect determination of the most used herbicide worldwide, glyphosate, was achieved by the SERS technique using hemin chloride as the reporter molecule. An incubation process between hemin and glyphosate solutions was required to obtain a reproducible Raman signal on SERS substrates consisting of silicon decorated with Ag nanoparticles (Si-AgNPs). At 780 nm of excitation wavelength, SERS spectra from hemin solutions do not show extra bands in the presence of glyphosate. However, the hemin bands increase in intensity as a function of glyphosate concentration. This allows the quantification of the herbicide using as marker band the signal associated with the ring breathing mode of pyridine at 745 cm−1. The linear range was from 1 × 10−10 to 1 × 10−5 M and the limit of detection (LOD) was 9.59 × 10−12 M. This methodology was successfully applied to the quantification of the herbicide in honey. From Raman experiments with and without silver nanoparticles, it was possible to state that the hemin is the species responsible for the absorption in the absence or the presence of the herbicide via vinyl groups. Likewise, when the glyphosate concentration increases, a subtle increase occurs in the planar orientation of the vinyl group at position 2 in the porphyrin ring of hemin over the silver surface, favoring the reduction of the molecule. The total Raman signal of the hemin-glyphosate incubated solutions includes a maximized electromagnetic contribution by the use of the appropriate laser excitation, and chemical contributions related to charge transfer between silver and hemin, and from resonance properties of Raman scattering of hemin. Incubation of the reporter molecule with the analyte before the conjugation with the SERS substrate has not been explored before and could be extrapolated to other reporter-analyte systems that depend on a binding equilibrium process"

    ELECTROCHEMICAL STUDY OF CIS-DIFERROCENYLETHENE DERIVATES

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    Ferrocene derivatives have been used in the synthesis of polymeric materials with thermal resistance and nonlinear optical properties, and in the field of supramolecular electrochemistry as redox switching receptors. For these reasons, during the past few years the electrochemical studies on ferrocenyl derivatives have been growing up. In order to characterize molecules with potential uses in the synthesis of polymeric materials and to understand its electrochemical functioning, this paper presents electrochemical studies on these chemicals: 1) cis-diferrocenylethenes derivates (Isopropyl cis-2,3-Diferrocenylacrylate; 2) cis-2,3-Diferrocenylacrylic Acid; 3) cis-2,3- Diferrocenylacrylohydrazide; 4) cis-2,3-Diferrocenylacrylic Acid Piperidide; 5) cis-3,4- Diferrocenyl-2-methylbut-3-en-ol, and 6) cis-1,1-Diphehyl-2,3-Diferrocenylprop-2-en-1-ol. All of the chemicals presented two oxidation processes (I-II), which were thought to be caused by the oxidation of the ferrocene groups, E1/2(I), E1/2(II), ÂżE1/2 (II-I). The comproportionation constant Kcom was calculated. According to this value, it can be proposed that the molecules containing a carbonyl group (1-4) present larger electronic communication compared to molecules with a hydroxy group (5-6). Uv-vis espectra of all compounds in butironitrile solution were obtained. A correlation between Kcom and Âż max was also observed

    COMPETITION BETWEEN THE REACTION MEDIUM AND NANOSTRUCTURED ZnO IN THE PHOTOCATALYTIC DEGRADATION OF ANTHRACENE. TOWARD AN OPTIMAL PROCESS FOR POLYCYCLIC AROMATIC HYDROCARBONS REMEDIATION

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    Contamination with polycyclic aromatic hydrocarbons (PAHs) is considered an important health issue due to the toxicity of these compounds. Photocatalytic degradation of anthracene, a representative molecule of PAHs, using the high quantum yield semiconductor ZnO, has been reported. The solubility of anthracene in water makes necessary to use mixtures with organic solvents in fundamental degradation studies. It is well known that some organic solvents participate in the photochemical transformation of this molecule. In the PAHs photocatalysis, the competition between a semiconductor and solvents has not reported. Therefore, in this work, we decided to study the photocatalytic degradation of anthracene with two common reaction media and nanostructured ZnO. The semiconductor was obtained by a one pot method which consists in an alkaline hydrolysis of Zn(CH3COO)2·2H2O in ethanol. Nanoparticles size in colloidal dispersion was calculated using UV-Vis spectroscopy and High Resolution Transmission Electron Microcopy (HR-TEM). ZnO powder was isolated and characterized by X-ray diffraction to be used in photocatalytic experiments. Surface area determination and photocurrent spectroscopic experiments were also carried out. Linear sweep voltammetries under darkness and UV-Vis irradiation indicate a charge separation due to photoexcitation. Photocatalytic experiments in ethanol:water pH 12 (1:1) and acetone:water pH 12 (1:1), with and without ZnO was explored. The results demonstrated that ethanol:water and acetone:water promotes the photo-transformation of anthracene to 9,10-anthraquinone. Meanwhile, ZnO transformed anthracene to benzoic acid and to 9,10-anthraquinone in ethanol:water and acetone:water, respectively. A faster photochemical kinetic is observed when acetone was used as solvent in the presence and in the absence of ZnO

    Delaying surgery for patients with a previous SARS-CoV-2 infection

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    The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

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    AimThe SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery.MethodsThis was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin.ResultsOverall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P ConclusionOne in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease
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