18 research outputs found

    Introduction of organic solvent solutions into inductively coupled plasma-atomic emission spectrometry using a microwave assisted sample introduction system

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    A microwave assisted sample introduction system based on the use of a TM010 cavity (MWDS2) has been employed for the introduction of 10% w/w organic solvent solutions in inductively coupled plasma atomic emission spectrometry (ICP-AES). Ethanol, propan-2-ol, formic and acetic acids have been used. Firstly, the effect of the incident microwave power and the sample uptake rate on the emission signal was evaluated. For all matrices tested, the higher emission signals were obtained when operating at the highest microwave power (i.e., 290 W) and sample uptake rate (400 mL/min). Results with the MWDS2 were compared with those afforded by a desolvation system based on the use of a domestic microwave oven (MWDS) and by a conventional sample introduction system (CS). The MWDS2 provides the highest emission signals (up to 7 and 17 times higher than those with the MWDS and the CS, respectively). As regards the matrix effects originated by the organic solutions, results demonstrate that the use of a microwave-based sample introduction system, mainly the MWDS2, affords a noticeable reduction in the matrix effects originated by the use of organic solvent solutions in ICP-AES with a conventional sample introduction system. This behaviour can be explained by taking into account the solution transport rates afforded by the different sample introduction systems. For all the analytical lines and matrices tested and operating at 400 mL/min, the MWDS2 gives rise to signal values that are, on average, 1.2 times the signal obtained with water. For the MWDS and the CS, this factor takes values of 1.6 and 2.0, respectively. Transient matrix effects have been observed operating with the MWDS2 when switching between water and an organic matrix solution. These transient effects result in a drift time about 4.5 times higher than those with a CS

    Employment and Industrial Relations in the Gig Economy: Challenges Resulted from the Employment Status

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    Bilgi ve iletişim teknolojilerinin yaygınlaşması ile platformlar üzerinden şahsen veya sanal olarak bir defaya mahsus yapılan görevler veya işlerden oluşan yeni bir piyasa gelişmektedir. Görevlerin arz ve talebini eşleştiren bu yeni piyasa, gig ekonomisi olarak tanımlanmakta ve gig ekonomisinde platform ve çalışan sayısı giderek artmaktadır. Gig ekonomisi birçok kişiye esnek çalışma ve ek kazanç fırsatları sunmasına rağmen, istihdam korumalarının yanı sıra, örgütlenme ve toplu pazarlık hakkının kullanımında yaşanan zorluklar ve kısıtlamalarla gündeme gelmektedir. Bu açıdan, gig-tabanlı çalışanlar platformlar tarafından özel sözleşmelerde çoğunlukla bağımsız yüklenici veya serbest çalışan olarak sınıflandırılmaktadır. Bu bağlamda, bu çalışma, temel olarak, gig ekonomisinin ayırt edici özellikleri, gig-tabanlı çalışma koşulları ve modelleri ile istihdam statüsünden kaynaklanan istihdamın korunması, örgütlenme ve toplu pazarlık açısından yaşanan zorluklara ilişkin ülke örnekleri ile yapılandırılmış kavramsal-teorik bir inceleme sunmayı ve bir takım sosyal politikalar önermeyi amaçlamaktadır.A new market consisting of one-off tasks or jobs performed personally or virtually through platforms is developing based on the widespread usage of information and communication technologies. The new market which matches the supply and demand of those tasks is described as the gig economy and the number of platforms and workers in the gig economy gradually increases. Although the gig economy offers opportunities for many people to get flexible work and additional earnings, it remains on the agenda the restrictions and challenges experienced in the usage of employment protections and rights to organise and collective bargaining. In this sense, gig-based workers are often classified as independent contractors or self-employed or freelancers in private contracts by the platforms running in the gig economy. In this context, this study mainly aims to present a conceptual-theoretical review structured with country instances related to the distinctive features of the gig economy, gig-based working conditions and models, and challenges experienced in terms of employment protections, organisation, and collective bargaining which result from employment statu and suggest a range of social policie

    Liquid-sample introduction in plasma spectrometry

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    Plasma-spectrometry techniques, namely inductively coupled plasma atomic emission spectrometry (ICP-AES) and plasma-based mass spectrometry (MS), are the most commonly used in analytical laboratories for elemental analysis in a wide variety of samples. In these techniques, the quality of the analysis strongly depends on appropriate selection of the sample-introduction system. For liquid samples, it basically comprises a nebulizer, which transforms the bulk solution into an aerosol, and a spray chamber, which modifies the characteristics of this aerosol and transports it to the plasma base through an injector tube. Sometimes, a desolvation system is incorporated to reduce the solvent load into the plasma. This article describes the different components of the sample-introduction system, emphasizing their main advantages and drawbacks. A review of the processes that affect the aerosol between generation and reaching the plasma is also included

    Immunization with antigenic extracts of Leishmania associated with Montanide ISA 763 adjuvant induces partial protection in BALB/c mice against Leishmania (Leishmania) amazonensis infection

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    Background/Purpose: A proper adjuvant has a relevant role in vaccine formulations to generate an effective immune response. In this study, total Leishmania antigen (TLA) formulated with Montanide ISA 763 or R848 as adjuvants were evaluated as a first generation Leishmania vaccine in a murine model. Methods: Immunization protocols were tested in BALB/c mice with a subcutaneous prime/boost regimen with an interval of 3 weeks. Mice immunized with unadjuvanted TLA and phosphate-buffered saline (PBS) served as control groups. On Day 21 and Day 36 of the protocol, we evaluated the humoral immune response induced by each formulation. Fifteen days after the boost, the immunized mice were challenged with 1 × 105 promastigotes of Leishmania (Leishmania) amazonensis in the right footpad (RFP). The progress of the infection was followed for 10 weeks; at the end of this period, histopathological studies were performed in the RFP. Results: Vaccines formulated with Montanide ISA 763 generated an increase in the production of immunoglobulin G (IgG; p < 0.05) compared with the control group. There were no statistically significant differences in IgG1 production between the study groups. However, immunization with TLA-Montanide ISA 763 resulted in an increase in IgG2a compared to the unadjuvanted control (p < 0.001). Also noteworthy was the fact that a significant reduction in swelling and histopathological damage of the RFP was recorded with the Montanide ISA 763 formulation. Conclusion: We conclude that the immunization of BALB/c mice with a vaccine formulated with TLA and Montanide ISA 763 generated a protective immune response against L. (L.) amazonensis, characterized by an intense production of IgG2a.Fil: Cargnelutti, Diego Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo; ArgentinaFil: Salomón, María Cristina. Universidad Nacional de Cuyo; ArgentinaFil: Celedon, Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Garcia Bustos, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; ArgentinaFil: Morea, Gastón. Universidad Nacional de Cuyo; ArgentinaFil: Cuello Carrión, Fernando Darío. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo; ArgentinaFil: Scodeller, Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo; Argentin

    Negotiating limits on algorithmic management in digitalised services: cases from Germany and Norway

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    Artificial intelligence (AI)-based algorithms are increasingly used to monitor employees and to automate management decisions. In this article, we ask how worker representatives adapt traditional collective voice institutions to regulate the adoption and use of these tools in the workplace. Our findings are based on a comparative study of union and works council responses to algorithmic management in contact centres from two similar telecommunications companies in Germany and Norway. In both case studies, worker representatives mobilised collective voice institutions to protect worker privacy and discretion associated with remote monitoring and workforce management technologies. However, they relied on different sources of institutional power, connected to co-determination rights, enforcement of data protection laws, and labour cooperation structures.Negotiating limits on algorithmic management in digitalised services: cases from Germany and NorwayacceptedVersio

    Head-to-Head Comparison of Three Vaccination Strategies Based on DNA and Raw Insect-Derived Recombinant Proteins against Leishmania

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    Parasitic diseases plague billions of people among the poorest, killing millions annually, and causing additional millions of disability-adjusted life years lost. Leishmaniases affect more than 12 million people, with over 350 million people at risk. There is an urgent need for efficacious and cheap vaccines and treatments against visceral leishmaniasis (VL), its most severe form. Several vaccination strategies have been proposed but to date no head-to-head comparison was undertaken to assess which is the best in a clinical model of the disease. We simultaneously assayed three vaccination strategies against VL in the hamster model, using KMPII, TRYP, LACK, and PAPLE22 vaccine candidate antigens. Four groups of hamsters were immunized using the following approaches: 1) raw extracts of baculovirus-infected Trichoplusia ni larvae expressing individually one of the four recombinant proteins (PROT); 2) naked pVAX1 plasmids carrying the four genes individually (DNA); 3) a heterologous prime-boost (HPB) strategy involving DNA followed by PROT (DNA-PROT); and 4) a Control including empty pVAX1 plasmid followed by raw extract of wild-type baculovirus-infected T. ni larvae. Hamsters were challenged with L. infantum promastigotes and maintained for 20 weeks. While PROT vaccine was not protective, DNA vaccination achieved protection in spleen. Only DNA-PROT vaccination induced significant NO production by macrophages, accompanied by a significant parasitological protection in spleen and blood. Thus, the DNA-PROT strategy elicits strong immune responses and high parasitological protection in the clinical model of VL, better than its corresponding naked DNA or protein versions. Furthermore, we show that naked DNA coupled with raw recombinant proteins produced in insect larvae biofactories -the cheapest way of producing DNA-PROT vaccines-is a practical and cost-effective way for potential "off the shelf" supplying vaccines at very low prices for the protection against leishmaniases, and possibly against other parasitic diseases affecting the poorest of the poor.Spanish GovernmentSpanish Government [AGL2008-00748, AGL2010-16678-GAN]Generalitat de Catalunya [2005 FI 01116]Generalitat de Cataluny

    Improved Canine and Human Visceral Leishmaniasis Immunodiagnosis Using Combinations of Synthetic Peptides in Enzyme-Linked Immunosorbent Assay

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    Visceral leishmaniasis is endemic in many areas of tropical and subtropical America where it constitutes a significant public health problem. It is usually diagnosed by enzyme-linked immunosorbent assays (ELISA) using crude Leishmania antigens, but a variety of other immunological methods may also be applied. Although these approaches are useful, historically their sensitivity and specificity have often been compromised by the use of complex mixtures of antigens. In this context, the use of combinations of purified, well-characterized antigens appears preferable and may yield better results. In the present study, combinations of peptides derived from the previously described Leishmania diagnostic antigens A2, NH, LACK and K39 were used in ELISA against sera from 106 dogs and 44 human patients. Improved sensitivities and specificities, close to 100%, for both sera of patients and dogs was observed for ELISA using some combinations of the peptides, including the detection of VL in dogs with low anti-Leishmania antibody titers and asymptomatic infection. So, the use of combinations of B cell predicted synthetic peptides derived from antigens A2, NH, LACK and K39 may provide an alternative for improved sensitivities and specificities for immunodiagnostic assays of VL

    Fatal intrahepatic hemorrhage after nadroparin use for total hip arthroplasty

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    Low-molecular-weight heparins have become the predominant choice for deep venous thrombosis prophylaxis and treatment. However, their use may cause bleeding complications. Intrahepatic bleeding is exceptional and only very few cases have been described. The authors present a unique case of fatal intrahepatic hematoma complicating nadroparin use in a 65-year-old woman with a hepatic cyst who was admitted to hospital for unilateral total hip arthroplasty. At autopsy, hemoperitoneum (2,000ml of blood and clots) was evident. A ruptured sub-capsular hematoma involving the right lobe of the liver was observed. The hemorrhage within the cyst induced by the nadroparin use was likely responsible for the subsequent hepatic hematoma, liver rupture, and death. This case highlights the need for pathologists and surgeons to be aware of the possibility of intrahepatic hematoma in patients who have received low-molecular-weight heparins, undergone major surgery and present postoperative hemodynamic instability, especially in those with preoperative diagnosis of hepatic cyst

    Treatment and secondary prevention of venous thromboembolism in cancer

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    Patients with cancer who develop venous thromboembolism (VTE) are at elevated risk for recurrent thrombotic events, even during anticoagulant therapy. The clinical picture is further complicated because these patients are also at increased risk of bleeding while on anticoagulants. In general, there are four key goals of treatment for VTE: preventing fatal pulmonary embolism (PE); reducing short-term morbidities associated with acute leg or lung thrombus; preventing recurrent VTE; and preventing the long-term sequelae of VTE (e.g., post-thrombotic syndrome and chronic thromboembolic pulmonary hypertension). A fifth goal – minimising the risk for bleeding while on anticoagulation – is particularly warranted in patients with cancer. Traditionally, pharmacological treatment of VTE has two phases, with the transition between phases marked by a switch from a rapid-acting, parenterally administered anticoagulant (such as unfractionated heparin (UFH), low-molecular-weight heparin (LMWH), or fondaparinux) to an oral vitamin K antagonist (e.g., warfarin). Recent clinical trials of established agents and the advent of new pharmacological options are changing this paradigm. Low-molecular-weight heparin continued for 6 months is more effective than warfarin in the secondary prevention of VTE in cancer patients without increasing the risk of bleeding and is now the preferred treatment option. Given the impact of VTE on short-term and long-term outcomes in patients with cancer, a group of health-care providers based in the United Kingdom gathered in London in 2009 to discuss recent data on cancer-associated thrombosis and to evaluate how these recommendations can be integrated or translated into UK clinical practice. This article, which is the third of four articles covering key topics in cancer thrombosis, focuses on treatment and secondary prevention of VTE in cancer patients

    Analysis of bioethanol samples through Inductively Coupled Plasma Mass Spectrometry with a total sample consumption system

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    Bioethanol real samples have been directly analyzed through ICP-MS by means of the so called High Temperature Torch Integrated Sample Introduction System (hTISIS). Because bioethanol samples may contain water, experiments have been carried out in order to determine the effect of ethanol concentration on the ICP-MS response. The ethanol content studied went from 0 to 50%, because higher alcohol concentrations led to carbon deposits on the ICP-MS interface. The spectrometer default spray chamber (double pass) equipped with a glass concentric pneumatic micronebulizer has been taken as the reference system. Two flow regimes have been evaluated: continuous sample aspiration at 25 μL min− 1 and 5 μL air-segmented sample injection. hTISIS temperature has been shown to be critical, in fact ICP-MS sensitivity increased with this variable up to 100–200 °C depending on the solution tested. Higher chamber temperatures led to either a drop in signal or a plateau. Compared with the reference system, the hTISIS improved the sensitivities by a factor included within the 4 to 8 range while average detection limits were 6 times lower for the latter device. Regarding the influence of the ethanol concentration on sensitivity, it has been observed that an increase in the temperature was not enough to eliminate the interferences. It was also necessary to modify the torch position with respect to the ICP-MS interface to overcome them. This fact was likely due to the different extent of ion plasma radial diffusion encountered as a function of the matrix when working at high chamber temperatures. When the torch was moved 1 mm plasma down axis, ethanolic and aqueous solutions provided statistically equal sensitivities. A preconcentration procedure has been applied in order to validate the methodology. It has been found that, under optimum conditions from the point of view of matrix effects, recoveries for spiked samples were close to 100%. Furthermore, analytical concentrations for real samples following the preconcentration method and the direct determination were not significantly different. The quantification method was finally based on external calibration with standards containing 50% (v/v) ethanol content.C. Sánchez would like to thank the Ministry of Education, Culture and Sports, Spain for the grant FPU 13/01438
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