103 research outputs found

    Studies of CH Activation in Unsaturated Amides and Esters by Trinuclear Metal Carbonyl Clusters of Osmium

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    The chemistry of the reaction of Os3(CO)10(NCCH3)2 with representatives of unsaturated amides and esters, RCOCHCH2 (R=(CH3)2N, CH3O) has been investigated. In these reactions, it has been observed that a CH bond on the β-carbon atom is readily activated by triosmium carbonyl clusters. The activation of β-carbon C-H bond in unsaturated amides and esters provides a robust platform for studying multicenter C-H bond transformations and for C-C bond formation via hydrogen shift and CO insertion processes. In this work, proposed mechanistic approaches have been taken in order to better understand and study the relationship between the characterized species. In addition, a few non-identified species have been predicted to exist. Furthermore, recommendations on how this work can be further studied and improved have been made. A series of activated unsaturated amides and esters: Os2(CO)6(µ-H)(µ O=C(N(CH3)2)CHCH), 1, Os4(CO)12(µ- O=C(N(CH3)2)CHCH)2, 2, Os3(CO)9(µ-O=C(N(CH3)2)CH2CHCCHC(N(CH3)2)=O), 3, Os3(CO)8(µ-O=C(N(CH3)2)CHCH)2, 4, Os6(CO)20(µ-H)(µ-O=C(N(CH3)2) CHCH), 5, HOs3(CO)10(µ-O=C(N(CH3)2)CHCH), 6, Os5(CO)15(µ-O=C(N(CH3)2)CHCH)2, 7, and Os3(CO)9(µ-H)(µ-O=C(OCH3)CHCH), 8, were synthesized and isolated. They are described in Chapter 1. Each of the new compounds has been characterized by FT-IR, NMR (1H), mass-spectra and single crystal X-ray diffraction analysis

    Neighborhood Semantics for Basic and Intuitionistic Logic

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    In this paper we present a neighborhood semantics for Intuitionistic Propositional Logic (IPL). We show that for each Kripke model of the logic there is a pointwise equivalent neighborhood model and vice versa. In this way, we establish soundness and completeness of IPL with respect to the neighborhood semantics. The relation between neighborhood and topological semantics are also investigated. Moreover, the notions of bisimulation and n-bisimulation between neighborhood models of IPL are defined naturally and some of their basic properties are proved. We also consider Basic Propositional Logic (BPL), a logic weaker than IPL introduced by Albert Visser, and introduce and study its neighborhood models in the same manner

    The effect of sulfoxo-bilactam-21-crown -7 on spermatogenesis in immature Balb/c mice

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    زمینه و هدف: کراون اترها ملکول های میزبان برای یون های فلزی و غیر فلزی هستند. توانایی کراون اترها در کنترل سیکل و تغییر فعالیت برخی از آنزیم ها گزارش شده است. در این مطالعه اثر یک کراون اتر جدید (سولفوکسو- بی لاکتام- 21- کراون-7) بر روی بافت بیضه و اسپرماتوژنز مورد بررسی قرار گرفته است. روش بررسی: در این مطالعه 24 سر موش نابالغ کوچک آزمایشگاهی (Balb/C) به سه گروه گروه کنترل (هیچ ماده ای دریافت نکردند)، شم )فقط توئین 80 دریافت کردند) و تجربی )سولفوکسو- بی لاکتام- 21- کراون-7 دریافت کردند) تقسیم شدند. Lethal dose 50 (LD50) دارو، به میزان 40 میلی گرم بر کیلوگرم تعیین شد. بر این اساس، دوز 20 میلی گرم بر کیلوگرم از این کراون اتر به روش درون صفاقی هر روز به مدت یک هفته به گروه تجربی تزریق شد. دو هفته پس از آخرین تزریق، حیوانات بیهوش شده و کشته شدند. خون جهت اندازه گیری هورمون از قلب گرفته شد. بافت بیضه، استخراج شد و جهت مطالعات بافت شناسی فیکس گردید. داده ها توسط آنالیز واریانس یکطرفه (ANOVA) و به دنبال آن تست توکی آنالیز شدند. یافته ها: تزریق درون صفاقی سولفوکسو- بی لاکتام- 21- کراون-7 (20 میلی گرم بر کیلوگرم) تغییر معنی داری در تعداد اسپرماتوگنی نوع A و B، اسپرماتوسیت اولیه و سلول های لیدیک در گروه تجربی در مقایسه با گروه کنترل و شم نشان نداد. افزایش هورمون جنسی مردانه، تستوسترون (001/0

    Seroprevalence of and Risk Factors for Toxoplasma gondii among Pregnant Women in Abyek Township of Qazvin Province , Iran (2013)

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     Objective: Toxoplasmosis is an important disease which is caused by the coccidian parasite Toxoplasma gondii. The aim of this study was to determineseroprevalence of and risk factors for T. gondii among pregnant women in Abyek township of Qazvin province by enzyme-linked immunosorbentassay method.Methods: Blood samples were taken from 200 pregnant women referred to the health centers of Abyek township. Immunoglobulin M (IgM)and IgGtiters and effects of some factors on incidence of the disease were evaluated. The collected data were statistically analyzed with SPSS 17 using Chisquaretest.Results: Anti toxoplasma IgM and IgG were positive in 2% and 29% respectively. Seropositive subjects were more frequently seen in women withage >30 years compared to younger women. No significant relationship was found between the seroprevalence of T. gondii infection and level ofeducation, residence area, history of abortion and gestational age.Conclusion: It was indicative of having a latent infection due to the previous exposure to toxoplasma parasite in this region.Keywords: Toxoplasma gondii, Prevalence, Pregnant women, Enzyme-linked immunosorbent assay, Immunoglobulin M

    Cross-Reaction between the Crude Hydatid Cyst Fluid Antigens of Human and Animals Origin in Response to Human IgG Class and Subclasses

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    The current work aimed to evaluate the cross-reactivity of human immune sera against crude hydatid fluid antigens of sheep, human, mouse, cattle, as well as B fraction of cystic fluid antigen. 30 balb/c mice were infected with sheep hydatid cyct fluid antigen containing protoscolex after the viability of these protoscolices was assessed. ANOVA was used to test the difference of themean of optical density (OD) values among case and control groups. The highest human IgG class antibody was against antigen B (0.93) and the lowest against cattle HCF antigen (0.32). The differences between responses to these antigens were statistically significant (P < 0.001). The sensitivity and specificity of ELISA test used for evaluating the responses of human total IgG to different hydatid cyst fluid (HCF) antigens among the case and control groups were 100 and 95.8%, respectively. Cross-reaction of human IgG class and subclasses responses was found almost for all the antigens with the best reaction against human and cattle (HCF) antigens and antigen B using a ratio of mean OD value to each antigen divided by the cut-off point value for the same antigen. Human sera showed a considerable cross-reactivity against all antigens by using ELISA

    A Review of Future Studies in the Field of Health Information Technology

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    Introduction: In order to adopt the right technologies, policy makers should have adequate information about the present and future advances. This study aimed to review future studies in the field of health information technology. Method: This review study was conducted in 2015. The databases including Scopus, Web of Science, ProQuest, Ovid Medline, and PubMed were sought between 2000 and 2015. Results: 11 papers were selected for the study. The papers were divided into two groups: forecasting the future of health information technology (n=7) and health information technology foresight (n=4). According to the results, it is better to use foresight approach for big and long-term goals. Conclusion: The results of foresight studies can be useful for making decision and policy-making in the field of health information technology, particularly at the national level

    Identifying and ranking the antecedents of digital ‎marketing development based on blockchain ‎technology ‎(case: aviation industry) ‎‎

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    Blockchain technology is one of the most promising technologies of this ‎century that has the potential to bring about fundamental changes in business ‎models in a wide range of industries. The current research seeks to identify ‎the antecedents of the development of digital marketing based on blockchain ‎technology from the point of view of marketing experts in the aviation ‎industry.This research is practical in terms of orientation and positivist from a ‎philosophical point of view, which was carried out using a mixed method.,In ‎this study, the antecedents of the development of digital marketing based on ‎blockchain technology were first extracted by literature review and semi-‎structured interviews, and with the help of experts, the final factors were ‎identified;Then, these factors in the form of Q cards were provided to ‎‏22‏‎ ‎marketing experts in the aviation industry who were selected purposefully ‎and finally their views were analyzed using exploratory factor analysis.The ‎participants in this research have ‎‏6‏‎ different views and their mental patterns ‎are categorized based on market variables, internal, content, technological, ‎human and environmental factors.The results of this research have given ‎useful insight to managers and decision makers in the aviation industry, so ‎that by knowing these factors, they can strengthen and develop digital ‎marketing in airline companies.

    Role of big data in the future of the banking industry with scenario planning approach

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    This research has been done with the aim of developing Iran's banking scenarios with an emphasis on big data. The current research is practical in terms of orientation and exploratory in terms of the goal. It is also mixed in terms of its philosophical, pragmatic and methodological foundations. To carry out the research in the first stage, 20 key drivers of the research were extracted through literature review and interviews with banking and technology experts. After screening with the fuzzy Delphi method, 8 factors were removed and the rest were evaluated with the Marcus decision making technique. The findings of the research show that the two factors of "technology regulation" and "technology transfer costs" were chosen as key uncertainties for developing research scenarios. Based on these two key uncertainties, four scenarios were developed based on interviews with the focus group with the titles of comprehensive banking, static banking, searching banking, wandering banking. In the comprehensive banking scenario, everything is in its optimal state; Technology transfer costs have decreased and regulators are supportive of the technologies. According to the findings of the research, considering drivers, key uncertainties and alternative scenarios by managers and decision makers can improve the performance and increase the competitive advantage of banks

    Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

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    Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations
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