Determination of pyrrolizidine alkaloids in dietary sources using a spectrophotometric method

Pyrrolizidine alkaloids (PAs) are a class of toxic compounds found in the composition of more than 6000 plants. People can be exposed to PAs by consuming phytotherapeutic products, food from crops contaminated with seeds of some species with high content of PAs, and/ or contaminated animal products like bee products. For this reason we developed and validated a method for quantitative determination of PAs, from the most frequently contaminated food sources, honey and flour. Colorimetric Ehrlich reagent method was used with standard addition (1mg/kg senecionine). The extraction solvent was methanol 50% acidified with citric acid to pH 2-3, as this solvent can be used for alkaloids and N-oxides. We found that, in extracting the alkaloid only once from the dietary sources, the percent of recovery is low (52.5% for honey, and 45.75% for flour). Using successive extractions, three times with the same solvent, the senecionine retrieval percentage increased to 86.0% for honey and 76.0% for flour. The method was validated using the following parameters: selectivity, linearity (0,25- 20 mg/ mL senecionine), accuracy (average recovery 93.5 - 107.93%) and precision (RSD 3,26-4.55%.). The calculated limit of quantification (0.174 mg/ mL) makes this method applicable for determining Pas occurring at toxic levels for consumers

Development of business schools in emerging markets: Learning through adoption and adaptation

The purpose of this study is to contribute to the understanding of the critical resources and capabilities that business schools (BS) have developed to achieve sustainable development. Framed within the resource-based theory, it analyzes seven of the top 50 BS from emerging markets (EM). It argues that these schools have grown through a development process of adopting and adapting business models, including teaching and research methodologies, organizational structures, and business practices; when they consolidated their local leadership, they started to follow a more idiosyncratic process. The findings shed light on the challenges that schools from EM face to deliver local impact while being measured by international standards and have implications for theory development, practice, and policymaking. In terms of theory, the findings show how the Global North model has exerted a determining influence in the development path of BS in EM, and, subsequently, how the pressure to respond to domestic demands has guided the acquisition of resources and the development of capabilities. For practice, the study reveals development patterns, clues about the challenges these BS face, and the range of solutions they have implemented. For policymaking, the case studies offer valuable lessons on how governments can design support systems for BS development

More actors, different play: sphenoethmoid cell intimately related to the maxillary nerve canal and cavernous sinus apex

Abstract The sphenoid sinus is one of the most morphologically variable and surgically important structures of the skull base. Located below the sella turcica, neighbored by parasellar regions, such as the orbital apex, pterygopalatine fossa and lateral sellar region (cavernous sinus), it is clinically related to these and surgically relevant as corridor for various approaches. Moreover, at the sphenoethmoidal junction, important variations occur, most of these related to the presence of the Onodi cells and the intrasinusal protrusions of the optic nerve. That is why any identified and previously undescribed morphological variation at that level must be added to the well-established protocols, clinical and surgical. During a retrospective CT study of the sphenoid sinus anatomical features a previously unreported morphology was encountered and is reported here. It refers to a unilateral sphenoethmoid cell (SEC), Onodi-positive, not only overriding the superior aspect of the sphenoid but also its lateral side to get intimately related to the maxillary nerve. As that SEC expanded medially to the cavernous sinus apex, it altered the usual endosinusal morphological correlations and also added itself within the limits of the Mullan's triangle. It appears so that such postero-infero-lateral extended pneumatization of an Onodi cell alters the surgical landmarks and also can blur clinical pictures, by adding maxillary and pterygopalatine signs and symptoms

Quality of life and special issues in women with inflammatory bowel diseases

Introduction. The impact of inflammatory bowel diseases (IBD) on the quality of life (QoL) of patients is significant and it has important social and professional consequences. Materials and methods. We aimed to describe the patients’ perspective regarding the impact of IBD on their overall QoL and to evaluate the differences between men and women. An observational cross-sectional study, that included 180 patients with IBD in clinical remission, was conducted. All the patients completed a number of 3 questionnaires in order to evaluate the general aspects of their QoL. A separate questionnaire was created regarding gender-specific issues in women with IBD encounter. Also, particular features such as the incidence of anemia and osteoporosis among IBD patients were documented. The data obtained were analyzed and compared between the two gender-classified groups. Results. According to the Short Inflammatory Bowel Disease Questionnaire (SIBDQ), patients had a general perception of a good QoL, but the impact was higher in women. Fatigue and tiredness were severely perceived almost to the same degree regardless of their gender, whereas anxiety and unemployment were more present in men. No significant differences in women with IBD during the active disease and during disease remission were found. Conclusions. The overall quality of life of IBD patients is affected in many aspects, leading to the deterioration of their social and professional lives, for both men and women, but some aspects remain gender-specific and require a personalized standard of care

Determination of pyrrolizidine alkaloids in dietary sources using a spectrophotometric method

Pyrrolizidine alkaloids (PAs) are a class of toxic compounds found in the composition of more than 6000 plants. People can be exposed to PAs by consuming phytotherapeutic products, food from crops contaminated with seeds of some species with high content of PAs, and/ or contaminated animal products like bee products. For this reason we developed and validated a method for quantitative determination of PAs, from the most frequently contaminated food sources, honey and flour. Colorimetric Ehrlich reagent method was used with standard addition (1mg/kg senecionine). The extraction solvent was methanol 50% acidified with citric acid to pH 2-3, as this solvent can be used for alkaloids and N-oxides. We found that, in extracting the alkaloid only once from the dietary sources, the percent of recovery is low (52.5% for honey, and 45.75% for flour). Using successive extractions, three times with the same solvent, the senecionine retrieval percentage increased to 86.0% for honey and 76.0% for flour. The method was validated using the following parameters: selectivity, linearity (0,25- 20 mg/ mL senecionine), accuracy (average recovery 93.5 - 107.93%) and precision (RSD 3,26-4.55%.). The calculated limit of quantification (0.174 mg/ mL) makes this method applicable for determining Pas occurring at toxic levels for consumers

Entrepreneurial Ecosystems and the Catalytic Role of Universities

As there is already a common understanding that economic development can be seen where entrepreneurial activity flourishes, governments became also interested to understand if entrepreneurial ecosystems can be built from scratch like an artificial ecosystem. Many of the local areas (cities, regions or small countries) that received an entrepreneurial label developed to this status mostly through a natural process. Silicon Valley is in this respect the well-known success story. Researchers started to get interest in conceptualizing entrepreneurial ecosystems in the last two decades. They were able to define and identify the key drivers for a successful entrepreneurial ecosystem making analogies with natural ecosystems. This paper aims to synthetize the most important findings in the research in this domain, summarizing the key factors needed to be in place in order for an ecosystem to be considered entrepreneurial with a significant economic, technological and societal impact. The models developed are useful for practitioners and policymakers. Central to such an ecosystem we consider to be higher education and research institutions, as they bring to the ecosystem the elements that are crucial for its success: talented and innovative people, innovations and research outcomes with high potential of commercialization, valuable networks