31 research outputs found

    Extinctions of aculeate pollinators in Britain and the role of large-scale agricultural changes

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    Pollinators are fundamental to maintaining both biodiversity and agricultural productivity, but habitat destruction, loss of flower resources, and increased use of pesticides are causing declines in their abundance and diversity. Using historical records we assessed the rate of extinction of bee and flower-visiting wasp species in Britain, from the mid 19th century to the present. The most rapid phase of extinction appears to be related to changes in agricultural policy and practice beginning in the 1920s, before the agricultural intensification prompted by the Second World War, often cited as the most important driver of biodiversity loss in Britain. Slowing of the extinction rate from the 1960s onwards may be due to prior loss of the most sensitive species and/or effective conservation programs

    Crystal structure and computational study of 3,4-dihydroxy-3-hydroxymethyl-9-methyl-6-methylidene-3a,4,5,6,6a,9,9a,9b-octahydroazuleno[4,5-b]furan-2,8(3H,7H)-dione

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    In the molecule of title compound, C15H20O6, also known as cynarinin A, the cyclopentane ring having twist conformation and a gamma-lactone ring assuming an envelope conformation are trans-and cis-fused, respectively, to a cycloheptane ring adopting a twist-chair conformation. In the crystal, O-H center dot center dot center dot O hydrogen bonds link neighbouring molecules, forming a three-dimensional network. Theoretical calculations of the molecular structure using the CNDO approximation and MOPAC PM3 geometry optimization are in satisfactory agreement with the results of the X-ray structure analysis

    Syntheses, neural protective activities, and inhibition of glycogen synthase kinase-3beta of substituted quinolines.

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    A new series of fifteen 5-, 6-, and 8-appended 4-methylquinolines were synthesized and evaluated for their neural protective activities. Selected compounds were further examined for their inhibition of glycogen synthase kinase-3β (GSK-3β) and protein kinase C (PKC). Two most potent analogs, compounds 3 and 10, show nanomolar protective activities in amyloid β-induced MC65 cells and enzymatic inhibitory activities against GSK-3β, but poor PKC inhibitory activities. Using normal mouse model, the distribution of the most potent analog 3 in various tissues and possible toxic effects in the locomotors and inhibition of liver transaminases activities were carried out. No apparent decline of locomotor activity and no inhibition of liver transaminases were found. The compound appears to be safe for long-term use in Alzheimer’s disease mouse model

    Comparison of Pheochromocytoma-Specific Morbidity and Mortality among Adults with Bilateral Pheochromocytomas Undergoing Total Adrenalectomy vs Cortical-Sparing Adrenalectomy

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    Importance: Large studies investigating long-term outcomes of patients with bilateral pheochromocytomas treated with either total or cortical-sparing adrenalectomies are needed to inform clinical management. Objective: To determine the association of total vs cortical-sparing adrenalectomy with pheochromocytoma-specific mortality, the burden of primary adrenal insufficiency after bilateral adrenalectomy, and the risk of pheochromocytoma recurrence. Design, Setting, and Participants: This cohort study used data from a multicenter consortium-based registry for 625 patients treated for bilateral pheochromocytomas between 1950 and 2018. Data were analyzed from September 1, 2018, to June 1, 2019. Exposures: Total or cortical-sparing adrenalectomy. Main Outcomes and Measures: Primary adrenal insufficiency, recurrent pheochromocytoma, and mortality. Results: Of 625 patients (300 [48%] female) with a median (interquartile range [IQR]) age of 30 (22-40) years at diagnosis, 401 (64%) were diagnosed with synchronous bilateral pheochromocytomas and 224 (36%) were diagnosed with metachronous pheochromocytomas (median [IQR] interval to second adrenalectomy, 6 [1-13] years). In 505 of 526 tested patients (96%), germline mutations were detected in the genes RET (282 patients [54%]), VHL (184 patients [35%]), and other genes (39 patients [7%]). Of 849 adrenalectomies performed in 625 patients, 324 (52%) were planned as cortical sparing and were successful in 248 of 324 patients (76.5%). Primary adrenal insufficiency occurred in all patients treated with total adrenalectomy but only in 23.5% of patients treated with attempted cortical-sparing adrenalectomy. A third of patients with adrenal insufficiency developed complications, such as adrenal crisis or iatrogenic Cushing syndrome. Of 377 patients who became steroid dependent, 67 (18%) developed at least 1 adrenal crisis and 50 (13%) developed iatrogenic Cushing syndrome during median (IQR) follow-up of 8 (3-25) years. Two patients developed recurrent pheochromocytoma in the adrenal bed despite total adrenalectomy. In contrast, 33 patients (13%) treated with successful cortical-sparing adrenalectomy developed another pheochromocytoma within the remnant adrenal after a median (IQR) of 8 (4-13) years, all of which were successfully treated with another surgery. Cortical-sparing surgery was not associated with survival. Overall survival was associated with comorbidities unrelated to pheochromocytoma: of 63 patients who died, only 3 (5%) died of metastatic pheochromocytoma. Conclusions and Relevance: Patients undergoing cortical-sparing adrenalectomy did not demonstrate decreased survival, despite development of recurrent pheochromocytoma in 13%. Cortical-sparing adrenalectomy should be considered in all patients with hereditary pheochromocytoma

    COMPARISON OF PHYTOCHEMICALS AND ANTIOXIDANT CAPACITY OF HYPERICUM PERFORATUM; WILD PLANT PARTS AND IN VITRO SAMPLES

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    The aim of study is to compare the phytochemicals and free radical scavenging activities in methanol extracts of flower, leaf, stem in vitro plantlet, callus of Hypericum perforatum L. In vitro cultures of H. perforatum was established by using MS-B5 medium contained plant growth regulators such as BAP, TDZ and picloram. Total phenolics and flavonoids were analysed by spectrophotometric methods.The stem was the richest in total phenolics (228.9 mg GAE/g extract) and flavonoids (102.4 mg QE/g extract). Quinic acid, gallic acid, (+)-catechin, ferulic acid, vanillic acid, p-coumaric acid, caffeic acid, and quercetin were determinated by LC-MS/MS. Free radical scavenging activities (ABTS and DPPH) of all samples were detected as IC50 values, and was compared to standards such as trolox and ascorbic acid. As a result, the stem exhibited the stronger antioxidant activities than other samples, and vanillic acid, ferulic acid and gallic acid could be produced by in vitro culture

    Impact of implementation of auxiliary bias-windings on controllable inductors for power electronic converters

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    The authors thank the SUMIDA Components & Modules GmbH in Obernzell, Germany, for manufacturing or machining most of the ferrite cores which were used to generate the presented measurement results. Proceedings of the 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe), held 7-11 September 2020 in Lyon, France.Parts of the work presented in this paper have been supported by the German Federal Ministry of Education and Research (BMBF). Project funding reference number: 16EMO0234
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