Synthesis, structure and dioxygen reactivity of a bis(µ-iodo)dicopper(I) complex supported by the [N-(3,5-di-tert-butyl-2-hydroxybenzyl)-N,N-di-(2-pyridylmethyl)]amine ligand

The air-sensitive bis(µ-iodo)dicopper(I) complex 1 supported by [N-(3,5-di-tert-butyl-2-hydroxybenzyl)-N,N-di-(2-pyridylmethyl)]amine (L) has been prepared by treating copper(I) iodide with L in anhydrous THF. Compound 1 crystallizes as a dimer in space group C2/c. Each copper(I) center has distorted tetrahedral N2I2 coordination geometry with Cu–N(pyridyl) distances 2.061(3) and 2.063(3) Å, Cu–I distances 2.6162(5) and 2.7817(5) and a CuCu distance of 2.9086(8) Å. Complex 1 is rapidly oxidized by dioxygen in CH2Cl2 with a 1 : 1 stoichiometry giving the bis(µ-iodo)peroxodicopper(II) complex [Cu(L)(µ-I)]2O2 (2). The reaction of 1 with dioxygen has been characterized by UV-vis, mass spectrometry, EPR and Cu K-edge X-ray absorption spectroscopy at low temperature (193 K) and above. The mass spectrometry and low temperature EPR measurements suggested an equilibrium between the bis(µ-iodo)peroxodicopper(II) complex 2 and its dimer, namely, the tetranuclear (peroxodicopper(II))2 complex [Cu(L)(µ-I)]4O4 (2). Complex 2 undergoes an effective oxo-transfer reaction converting PPh3 into OPPh3 under anaerobic conditions. At sufficiently high concentration of PPh3, the oxygen atom transfer from 2 to PPh3 was followed by the formation of [Cu(PPh3)3I]. The dioxygen reactivity of 1 was compared with that known for other halo(amine)copper(I) dimers

Electron Paramagnetic Resonance Studies of Succinate:Ubiquinone Oxidoreductase from Paracoccus denitrificans

Electron paramagnetic resonance (EPR) studies of succinate:ubiquinone oxidoreductase (SQR) from Paracoccus denitrificans have been undertaken in the purified and membrane-bound states. Spectroscopic “signatures” accounting for the three iron-sulfur clusters (2Fe-2S, 3Fe-4S, and 4Fe-4S), cytochromeb, flavin, and protein-bound ubisemiquinone radicals have been obtained in air-oxidized, succinate-reduced, and dithionite-reduced preparations at 4–10 K. Spectra obtained at 170 K in the presence of excess succinate showed a signal typical of that of a flavin radical, but superimposed with another signal. The superimposed signal originated from two bound ubisemiquinones, as shown by spectral simulations. Power saturation measurements performed on the air-oxidized enzyme provided evidence for a weak magnetic dipolar interaction operating between the oxidized 3Fe-4S cluster and the oxidized cytochrome b. Power saturation experiments performed on the succinate- and dithionite-reduced forms of the enzyme demonstrated that the 4Fe-4S cluster is coupled weakly to both the 2Fe-2S and the 3Fe-4S clusters. Quantitative interpretation of these power saturation experiments has been achieved through redox calculations. They revealed that a spin-spin interaction between the reduced 3Fe-4S cluster and the cytochrome b (oxidized) may also exist. These findings form the first direct EPR evidence for a close proximity (≤2 nm) of the high potential 3Fe-4S cluster, situated in the succinate dehydrogenase part of the enzyme, and the low potential, low spin b-heme in the membrane anchor of the enzyme

Tinklalaidės neformaliajame mokymesi: socialinių medijų naudojimas asmeninės mokymosi aplinkos, asmeninio mokymosi tinklo kūrimui

The use of second-generation web technology (WEB2) in education is emphasising the role of social media as educational sources. Researchers that are analysing personal learning environments (Schaffert, Kalz, 2009; Dabbagh, Kitsantas, 2012), personal learning networks (Couros, 2010) suggest the importance of social media, although this emphasis is attributed to the collaborative interaction of learners. To comprehensively assess the potential of podcasts as social media in the creation of personal learning environments, personal learning networks, the research described in this article does not restrict the definition of podcasts as the potential of collaboration provided by social media. In this article, attention is directed towards the potential of podcasts in the creation of personal learning environment and personal learning networks. By using integrated information behaviour module analysis to determine if the students of Lithuanian higher education institutions value the potential of informal learning provided by podcasts. To determine if these technologies are used for the formation of personal learning environments, personal learning networks, a discussion group research was conducted. During the research the analysis of participant podcast usage showed there is interaction between media content used for recreation and media content used for formal and informal learning. This means that the participants of the research use podcasts to create personal learning environments. On the other hand, this interaction is minimal, created only by the learners and reasoned by the search of educational podcasts. The analysis of the experiences of the discussion participants revealed that the collaborative interaction between learners involved in the research in searching, sharing and using podcasts in the process of learning is not intensive, it is typically fragmented. This allows to point out that the communities that use podcasts for informal learning are not forming. This shows that the potential of podcasts in creating a learning network is not fulfilled, and that podcasts don’t inspire participatory learning.Antrosios kartos saityno technologijų (WEB2) naudojimas mokymesi nurodo socialinių medijų kaip mokymosi šaltinių, išteklių reikšmės augimą. Šiame straipsnyje dėmesys atkreipiamas į tinklalaidžių potencialą besimokančiųjų asmeninės mokymosi aplinkos, asmeninio mokymosi tinklo kūrimui. Mokslininkai, analizuojantys asmeninę mokymosi aplinką (Schaffert, Kalz, 2009; Dabbagh, Kitsantas, 2012), asmeninius mokymosi tinklus (Couros, 2010), nurodo išskirtinę socialinių medijų svarbą. Tačiau toks socialinių medijų sureikšminimas siejamas su besimokančiųjų bendradarbiaujamosios sąveikos užtikrinimu. Šiame straipsnyje pristatomame tyrime siekiant visapusiškai įvertinti tinklalaidžių kaip socialinių medijų potencialą kuriant asmeninę mokymosi aplinką, asmeninį mokymosi tinklą, neapsiribota tik jų kaip socialinių medijų teikiamų bendradarbiavimo galimybių įvertinimu. Taikant integruoto informacinės elgsenos modelio tyrimo prieigą nustatant, kaip Lietuvos aukštųjų mokyklų studentai vertina tinklalaidžių neformaliojo savaiminio mokymosi potencialą: ar šios technologijos naudojamos asmeninei mokymosi aplinkai, asmeniniam mokymosi tinklui formuoti, buvo atliktas diskusijų grupių tyrimas. Tyrimo metu atlikta diskusijos dalyvių tinklalaidžių naudojimo analizė parodė, kad yra formuojama sąveika tarp pramogoms ir formaliajam bei neformaliajam mokymuisi naudojamo šių naujųjų medijų turinio. Tai reiškia, kad tyrimo dalyviai tinklalaides naudoja asmeninės mokymosi aplinkos kūrimui. Tačiau ši sąveika yra minimali, kuriama tik pačių besimokančiųjų, ji grindžiama mokymosi turinio tinklalaidžių saviieška. Diskusijos dalyvių patirčių analizė atskleidė, kad bendradarbiaujamoji sąveika tarp tyrime dalyvavusių besimokančiųjų ieškant, dalijantis, naudojant tinklalaides mokymuisi nėra intensyvi, jai būdingas fragmentiškumas. Tai leidžia pastebėti, kad neformaliojo mokymosi naudojant tinklalaides bendruomenės nesiformuoja. Tai rodo, kad tinklalaidžių potencialas neišnaudojamas dalyvaujamojo mokymosi tinklo kūrimui, tinklalaidės neinspiruoja dalyvaujamojo mokymosi

Exhaled Nitric Oxide is Associated with Allergic Inflammation in Children

Exhaled nitric oxide (eNO) has been proposed as a noninvasive marker of airway inflammation in asthma. In asthmatic patients, exhaled NO levels have been shown to relate with other markers of eosinophilic recruitment, which are detected in blood, sputum, bronchoalveolar lavage fluid and bronchial biopsy samples. The purpose of this study was to assess the possible relationship between eNO and allergic inflammation or sensitization in childhood asthma and allergic rhinitis. Subjects consisted of 118 asthmatic children, 79 patients with allergic rhinitis, and 74 controls. Their age ranged from 6 to 15 yr old. eNO level, peripheral blood eosinophil count, eosinophil cationic protein (ECP), serum total IgE level and specific IgE levels were measured. Methacholine challenge test and allergic skin prick test for common allergens were performed in all subjects. Atopic group (n = 206, 44.48 ± 30.45 ppb) had higher eNO values than non-atopic group (n = 65, 20.54 ± 16.57 ppb, P < 0.001). eNO level was significantly higher in patients with asthma (42.84 ± 31.92 ppb) and in those with allergic rhinitis (43.59 ± 29.84 ppb) than in healthy controls (27.01 ± 21.34 ppb, P < 0.001) but there was no difference between asthma and allergic rhinitis group. eNO also had significant positive correlations with Dermatophagoides pteronyssinus IgE level (r = 0.348, P < 0.001), Dermatophagoides farinae IgE level (r = 0.376, P < 0.001), and the number of positive allergens in skin prick test (r = 0.329, P = 0.001). eNO had significant positive correlations with peripheral blood eosinophil count (r = 0.356, P < 0.001), serum total IgE level (r = 0.221, P < 0.001), and ECP (r = 0.436, P < 0.001). This study reveals that eNO level is associated with allergic inflammation and the degree of allergic sensitization

Polyphenols enhance the activity of alkylating agents in leukaemia cell lines

Polyphenols have been shown to sensitize solid tumours to alkylating agents such as cisplatin, and induce apoptosis and/or cell-cycle arrest. Here, we assess the effects of five polyphenols alone and in combination with three alkylating agents: cisplatin, cyclophosphamide and chlorambucil in lymphoid and myeloid leukaemia cells lines, and non-tumour control cells. In lymphoid leukaemia cell lines there was a synergistic reduction in ATP and glutathione levels, an induction of cell cycle arrest, DNA damage and apoptosis when quercetin, apigenin, emodin and rhein were combined with cisplatin and cyclophosphamide; and when apigenin and rhein were combined with chlorambucil. In myeloid leukaemia cells quercetin, apigenin and emodin showed a similar synergistic effect with all alkylating agents; however antagonistic effects were observed with some or all alkylating agents when combined with emodin, rhein and cis-stilbene. All synergistic effects were associated with reduced glutathione levels, DNA damage and apoptosis; whilst during antagonism the reverse effects were observed. The combination of alkylating agents, particularly cisplatin with polyphenols could be promising for the treatment of lymphoid leukaemias, with apigenin showing the greatest effects. Likewise in myeloid cells apigenin also synergised the action of all alkylating agents, suggesting that apigenin may also be beneficial in myeloid leukaemias

A 680,000-person megastudy of nudges to encourage vaccination in pharmacies

Encouraging vaccination is a pressing policy problem. To assess whether text-based reminders can encourage pharmacy vaccination and what kinds of messages work best, we conducted a megastudy. We randomly assigned 689,693 Walmart pharmacy patients to receive one of 22 different text reminders using a variety of different behavioral science principles to nudge flu vaccination or to a business-as-usual control condition that received no messages. We found that the reminder texts that we tested increased pharmacy vaccination rates by an average of 2.0 percentage points, or 6.8%, over a 3-mo follow-up period. The most-effective messages reminded patients that a flu shot was waiting for them and delivered reminders on multiple days. The top-performing intervention included two texts delivered 3 d apart and communicated to patients that a vaccine was “waiting for you.” Neither experts nor lay people anticipated that this would be the best-performing treatment, underscoring the value of simultaneously testing many different nudges in a highly powered megastudy

Discovery of a heat-generated compound DHD derived from Patrinia villosa water extract with inhibitory effects on colon cancer cells viability and migration

Introduction: The plant Patrinia villosa Juss. (PV) has long been used as a medicinal herb for treating intestinal disorders. Pharmacological activities such as anti-oxidation, anti-inflammation, and anti-cancer effects of compounds isolated from PV have been reported, but these bioactive compounds were not derived from PV water extract (PVW). Therefore, in the present study, we aimed to identify the active component(s) of PVW which exhibit inhibitory activities in colon cancer cells viability and migration.Methods: Human colon cancer HCT116 cells were treated with the isolated compounds of PVW and then subjected to MTT and transwell migration assays.Results: Our results showed that an active compound in PVW, 8,9-didehydro-7-hydroxydolichodial (DHD) inhibited cell viability of HCT116 cells, with IC50 value at 6.1 ± 2.2 μM. Interestingly, DHD was not detected in the herbal material of PV. Further investigation revealed that DHD is in fact a heat-generated compound derived from a natural compound present in PV, namely valerosidate. Valerosidate also reduced cell viability in HCT116 cells, with IC50 value at 22.2 ± 1.1 μM. Moreover, both DHD (2.75 μM) and valerosidate (10.81 μM) suppressed cell migration in HCT116 cells, with inhibitory rates at 74.8% and 74.6%, respectively. In addition, western blot results showed that DHD (5.5 μM) could significantly increase p53 expression by 34.8% and PTEN expression by 13.9%, while valerosidate (21.6 μM) could increase expressions of p53 and PTEN by 26.1% and 34.6%, respectively in HCT116 cells after 48 h treatment.Discussion: Taken together, this is the first report that a naturally-occurring valerosidate present in PV could actually transform to DHD by thermal hydrolysis, and both compounds exhibited inhibitory effects on cell viability and migration in HCT116 cells via increasing the expressions of tumor suppressors (p53 and PTEN). Our findings demonstrated that valerosidate is present in raw herb PV but not in PVW, while DHD is present in PVW rather than in raw herb PV. This difference in chemical profiles of raw herb and boiled water extract of PV may affect the anti-cancer activity, and hence further investigations are warranted

Low-Dimensional Palladium Nanostructures for Fast and Reliable Hydrogen Gas Detection

Palladium (Pd) has received attention as an ideal hydrogen sensor material due to its properties such as high sensitivity and selectivity to hydrogen gas, fast response, and operability at room temperature. Interestingly, various Pd nanostructures that have been realized by recent developments in nanotechnologies are known to show better performance than bulk Pd. This review highlights the characteristic properties, issues, and their possible solutions of hydrogen sensors based on the low-dimensional Pd nanostructures with more emphasis on Pd thin films and Pd nanowires. The finite size effects, relative strengths and weaknesses of the respective Pd nanostructures are discussed in terms of performance, manufacturability, and practical applicability

The Role of Age in Predicting the Outcome of Caustic Ingestion in Adults: A Retrospective Analysis

<p>Abstract</p> <p>Background</p> <p>Although the outcomes of caustic ingestion differ between children and adults, it is unclear whether such outcomes differ among adults as a function of their age. This retrospective study was performed to ascertain whether the clinical outcomes of caustic ingestion differ significantly between elderly and non-elderly adults.</p> <p>Methods</p> <p>Medical records of patients hospitalized for caustic ingestion between June 1999 and July 2009 were reviewed retrospectively. Three hundred eighty nine patients between the ages of 17 and 107 years were divided into two groups: non-elderly (< 65 years) and elderly (≥ 65 years). Mucosal damage was graded using esophagogastroduodenoscopy (EGD). Parameters examined in this study included gender, intent of ingestion, substance ingested, systemic and gastrointestinal complications, psychological and systemic comorbidities, severity of mucosal injury, and time to expiration.</p> <p>Results</p> <p>The incidence of psychological comorbidities was higher for the non-elderly group. By contrast, the incidence of systemic comorbidities, the grade of severity of mucosal damage, and the incidence of systemic complications were higher for the elderly group. The percentages of ICU admissions and deaths in the ICU were higher and the cumulative survival rate was lower for the elderly group. Elderly subjects, those with systemic complications had the greatest mortality risk due to caustic ingestion.</p> <p>Conclusions</p> <p>Caustic ingestion by subjects ≥65 years of age is associated with poorer clinical outcomes as compared to subjects < 65 years of age; elderly subjects with systemic complications have the poorest clinical outcomes. The severity of gastrointestinal tract injury appears to have no impact on the survival of elderly subjects.</p