42 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

    Isolation of oleuropein from olive leaf by effective method and investigation of its antimicrobial properties

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    215-223Natural products play an important role in the production and development of food and medicine. In olive tree cultivation and olive processing industry, vast amounts of by-products are yielded. Olive leaves constitute the major by-product of olive industry. Olive leaf is potential source of phenolic compounds. Plant polyphenols have attracted great interest due to their antimicrobial activities. It was aimed to isolate the oleuropein compound from olive leaf and to identify its antimicrobial effects in this research. In the first stage, methanol extract was obtained from the olive leaf. After then, ethyl acetate extract (including oleuropein with 93.5% purity) procured from methanol extract. Ethyl acetate extract was subjected to chromatographic technique to obtain oleuropein in high purity (97.6%). The structure of oleuropein was determined by spectroscopic method including 1H and 13C NMR besides comparing isolated oleuropein with the standard commercially obtained. Antimicrobial activity of methanol extract, ethyl acetate extract and oleuropein was investigated on Bacillus subtilis, Candida tropicalis, Lactobacillus brevis, Lactobacillus plantarum, Proteus vulgaris, Saccharomyces cerevisiae, Salmonella enteritidis microorganisms by 96-well microtiter plate method. It was determined that MIC (Minimum Inhibitory Concentration) values of olive leaf products ranged between 1:1 (50 mg/mL) and 1:8 (6.25 mg/mL) for tested microorganisms

    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

    FTIR spectroscopic and quantum-chemical studies on some tribromoindenes and their isomers

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    Combined experimental and computational studies on molecular structure of newly synthesised transtirans 1,2,3-tribromo-1,2,3-trihydro-(1)H-benz[f]indene (TTTBI) were reported. Also, only computational studies were done for cis-trans-1,2,3-tribromo-1,2,3-trihydro-(1)H-benz[f]indene (CTTBI) and cis-cis-1,2,3-tribromo-1,2,3-trihydro-(1)H-benz[f]indene (CCTBI) in order to understand the vibrational spectra and molecular parameters of them. The geometry optimization and vibrational wave numbers of the title molecules were carried out with the Gaussian98 program package by using Hartree-Fock (HF) and Density Functional Theory (DFT) with B3LYP functional and 6-31G (d) basis set. All calculations were done for the title compounds in their ground states. Especially for CTTBI and CCTBI, which could not be synthesized yet, these kind of pre-calculations take an important role for their synthesis process. Also crystal structural parameters of TTTBI by single-crystal X-ray diffraction method was used as input for computational study of it. Observed and calculated vibrational wave numbers were compared. Because the use of benz[f]indene as a cyclopentadienyl ligand attracted much attention because an annulated benzo ring might increase both the stereocontrol and productivity of catalytic system, TTTBI and other computationally studied and modeled two molecules may play an important role of other types of compounds as a starting structures

    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

    Persistent nesting by <i>Anthophora</i> Latreille, 1803 (Hymenoptera: Apidae) bees in ash adjacent to an active volcano

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    Ground-nesting bees use a variety of substrates in which to establish cells and complete their reproductive cycles. Here we document the highly aberrant occurrence of a solitary bee species, Anthophora squammulosa Dours, 1870 (Hymenoptera: Apidae: Anthophorini), nesting within meters of an active volcanic crater in Nicaragua, Central America. The nest location is exposed to continuous, strongly acidic gas emissions (>2.7 ppm of SO2), and sporadic vent clearing episodes that blanket the surrounding area with ash and tephra. An assessment of floral resources available within the expected homing distance of the species was cross-referenced with pollen carried by females returning to their nests. At this site, A. squammulosa appears to forage almost exclusively on a single plant, Melanthera nivea (L.) Small, 1903 (Asteraceae), that is adapted to volcanic acidic rain, despite being widely accepted as a generalist bee in the remainder of its range. Notwithstanding the extreme nature of the site, and the co-occurrence of specialist natural enemies and predators, the possibility exists that the site is selected for its beneficial attributes, such as the loose, well-drained substrate and the absence of vegetation. The converse is that the site is sub-optimal with the population constrained by habitat patchiness and limited dispersal options
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