1,804 research outputs found
Reworked acritarchs as provenance indicators in the Lower Palaeozoic of Denmark
No full textProfuse and well-preserved acritarchs were recovered from subsurface Lower Palaeozoic successions cored by the boreholes Slagelse-1 and Pernille-1 (Danish-North German Basin). Together with Llandovery in situ microphytoplankton, reworked Cambrian and Ordovician species occur. The reworked Ordovician acritarchs show a clear Perigondwanan palaeobiogeographic affinity and indicate elastic sedimentary input from a Perigondwanan-related terrane located south of the East European Platform. Microfloral similarity enables identification of the detrital source area with the Avalonia Terrane. The present data also suggest that development of a foreland basin marginal to the Caledonian Deformation Front in the Danish-North German Basin started in Early Silurian times
Quantitative evaluation of microplankton palaeobiogeography in the Ordovician-Early Silurian of the northern Trans European Suture Zone: implications for the timing of the Avalonia-Baltica collision
No full textQuantitative analysis of assemblage similarity among chitinozoan and acritarch associations recovered from various sedimentary sequences across the Trans European Suture Zone (TESZ: southern Baltic Sea and northern Germany region), permits evaluation of changes in microplankton palaeobiogeography during the Ordovician in the study area. The present data confirm strong palaeobiogeographic differences between the lower Ordovician of the Rugen area, and the coeval domains of the East European Platform (EEP), corroborating the idea that the subsurface of Rugen should be considered palaeogeographically as the eastern extension of Avalonia. Cluster analysis of chitinozoan assemblages from numerous wells in the Rugen area, and one well from the southern margin of the EEP indicates that chitinozoan bioprovincialism reached its maximum during the Llanvirn; during this period, the Rugen microplankton communities were clearly Gondwanan in character. Calculations using the coefficient of similarity support the conclusion of a high similarity between Llanvirn acritarch assemblages from the Rugen subsurface and from coeval Perigondwana localities (e.g. Tunisia). Since the early Caradoc, this Gondwanan affinity of the Rugen microfossils starts to lessen, and becomes negligible during the late Caradoc. During latest Caradoc-early Ashgilll through Llandovery times the chitinozoan assemblages from either side of the TESZ are undistinguishable. If palaeobiogeographical differentiation is primarily related to palaeolatitudinal distance, then the present data support closure of the Tornquist Ocean during late Caradoc-Ashgill times. The presence of reworked Llanvirn acritarchs of Perigondwanan affinity in middle Ashgill sedimentary sequences at the southern margin of the EEP, clearly shows that by this time erosion of an uplifted area was taking place. Accordingly, the closure of the Tornquist Ocean, and consequent Avalonia-Baltica collision must have taken place during the time interval between the middle Caradoc and the early middle Ashgill (Rawtheyan). New chitinozoan data from boreholes H 2 and K 5, offshore of Rugen Island, northern Germany, allow for precise biostratigraphic dating. In the pre-Devonian part of H 2, Siphonochitina formosa indicates an Abereiddian (Early Llanvirn) age, facilitating correlation with boreholes Binz 1/73 and Lohme 2/70 of Rugen. In borehole K 5, the occurrence of Belonechitina robusta and Tanuchitina bergstroemi permits attribution of the investigated pre-Carboniferous sequence to the middle-late Caradoc, and, possibly, early Ashgill. (C) 2001 Elsevier Science B.V. All rights reserved
Timing of the Avalonia-Baltica plate convergence as inferred from palaeogeographic and stratigraphic data of chitinozoan assemblages in west Pomerania, northern Poland
No full textOrdovician-Silurian palynostratigraphy (Chitinozoa and acritarchs) of the G14-1/86 borehole, southern Baltic Sea
No full textBorehole G 14-1/86, located in the Baltic Sea between the Tornquist Zone and the Caledonian Deformation Front/Thor Suture, penetrates a Lower Palaeozoic sedimentary succession deposited on the south-western margin of the East European Platform. Detailed palynological analysis of the Ordovician and Silurian successions enables precise dating and facilitates provenance interpretation of the sedimentary sequence. The following chitinozoan biozones are identified: Cyatho-chitina primitiva Biozone (early - early late Arenig); Laufeldochitina striata Biozone (late Abereiddian - late Llandeilan) and Ancyrochitina merga Biozone (Cautleyan - Rawtheyan, middle Ashgill). A further chitinozoan assemblage is possible to be correlated with the global Spinachitina maennili Biozone (uppermost Rhuddanian - lower Telychian). A relatively diversified acritarch assemblage of Ashgill age (independently dated by Chitinozoa) also occurs. This assemblage contains numerous reworked forms of Llanvirn, Tremadoc and late Cambrian ages. The reworked Llanvirn acritarchs are typical of the high-latitude Perigondwanan micro-phytoplankton palaeobioprovince and testify to detrital input of Gondwanan-related source during the Ashgill, suggesting that by this time the Tornquist Ocean was closed
Micropalaeontology of a Moroccan Ordovician deposit yielding soft-bodied organisms showing Ediacara-like preservation
No full textA newly discovered locality of an hitherto unknown age, but now estimated to the Late Ordovician, in south-eastern Morocco has yielded numerous specimens of problematic soft-bodied metazoans preserved in coarse sandstones. The excellent preservation of the recovered specimens permits an improved understanding of both the palaeobiology of these Ordovician metazoans and the taphonomic processes associated with them. This style of soft-tissue preservation is closely comparable to that of the late Neoproterozoic problematic Ediacaran organisms, and is virtually absent in the Phanerozoic. Palynological analysis (chitinozoans and acritarchs) of shaly intercalations in an ophiuroid-bearing sandstone slab facilitates accurate identification of the site as belonging to the Upper Ktaoua Formation and thus a relative dating of the associated fossils. The chitinozoan assemblage is relatively well preserved, moderately diverse and closely comparable to the previously described chitinozoan fauna from the Upper Ktaoua Formation (Rawtheyan, late middle Ashgill age). Acritarchs are abundant but mostly ill-preserved; nonetheless they clearly indicate an undifferentiated Ashgill age, consistent with the chitinozoan chronostratigraphic result. These datings prove that the newly discovered Moroccan metazoan assemblage contains one of the oldest known paropsonemids, and possibly some of the youngest protolyelloids and aglaspidids. The new finds also show that Ediacara-like coarse-elastic preservation did not completely vanish with the onset of the Phanerozoic. (C) Etditions scientifiques et medicales Elsevier SAS
Recent Developments on the Elution by Characteristic Points Method for Rapid and Accurate Determination of Adsorption Isotherms
No full textAdsorption isotherms are the most important pieces of information needed to understand the analytical and preparative separation system. Several methods are used for their determinations. In this poster we will analyze the elution by characteristic point method (ECP) that is faster and also consumes less amounts analyte and solvent as compared to classic methods such as the frontal analysis (FA) and the perturbation peak method. Classically, ECP is conducted by integrating the diffuse part of an overloaded elution profile, which means that just one single overloaded elution profile and a calibration curve is needed to determine the adsorption isotherm. However, the ECP method is derived assuming that the column has infinite efficiency and that the injection profile is rectangular. All deviation from this will lead to errors in the determined adsorption isotherm. Because the adsorption isotherm is also integrated, a continuous diffuse part of the elution profiles is required. This means that adsorption isotherms from only tailing and fronting peaks could classically only be determined. In this poster we will present: (i) A method to experimentally achieve rectangular injection-profiles [1]. (ii) Determination of the raw slope of the adsorption isotherm data without integrating the elution profile. (iii) Strategies to expand the ECP method for the determination of more complex adsorption isotherms including such containing inflection points [3]. [1] J. Samuelsson, T. Fornstedt, Anal. Chem. 80 (2008) 7887. [2] J. Samuelsson, T. Undin, A. Törncrona, T. Fornstedt, J. Chromatogr. A 1217 (2010) 7215. [3]. J. Samuelsson, T. Undin, T. Fornstedt, J. Chromatogr. A, under review</p
Effect of Desmodium adscendens fraction F1 (DAF1) on tone and agonist-induced contractions of guinea pig airway smooth muscle
No full textPT: J; CR: ADDY ME, 1984, J ETHNOPHARMACOL, V11, P283 ADDY ME, 1986, J ETHNOPHARMACOL, V18, P13 ADDY ME, 1987, PHYTOTHER RES, V1, P1080 BURKA JF, 1985, PROSTAGLANDINS, V29, P529 CONSTANTINE JW, 1965, J PHARM PHARMACOL, V17, P384 LULICH KM, 1979, CLIN EXP PHARM PHYSL, V6, P625 OREHEK J, 1973, NATURE-NEW BIOL, V245, P84 SAAD MH, 1983, CAN J PHYSIOL PHARM, V61, P876 SAMUELSSON B, 1983, SCIENCE, V220, P568 SCHULMAN ES, 1982, J APPL PHYSIOL, V53, P589 STILL WC, 1978, J ORG CHEM, V43, P2923 WASSERMAN MA, 1983, ADV PROSTAGLANDIN TH, V12, P133; NR: 12; TC: 8; J9: PHYTOTHER RES; PG: 6; GA: AX428Source type: Electronic(1
Elderly patients undergoing colorectal cancer surgery : can care be further improved?
No full textIntroduction: Colorectal cancer (CRC) is one of the most common malignancies affecting approximately 6 400 new patients/year in Sweden of which 44% are 75 years and older at diagnosis. In order to identify potential predictors for surgical outcome and areas of improvement, this thesis aims to illuminate different aspects in the care of patients aged 75 years and older, undergoing CRC surgery.Methods: The studies in this thesis make use of a wide range of methods such as epidemiological methods: register based in study I and II, and prospective observational cohort study (IV). Qualitative methods with inductive content analysis were used in study III.Aims and Results: Study I investigated the characteristics of elderly colon cancer patients and how they are managed and treated compared to their younger counterparts when undergoing resection. Elderly patients were less often completely staged, and less often evaluated at a multidisciplinary team conference (MDT) prior to surgery. Furthermore, fewer elderly patients underwent curative resection and were more often subjected to emergency surgery. Study II investigated if there is an association in elderly CRC patients between use of potentially inappropriate medication (PIM) at the time of surgery, and postoperative mortality and length of hospital stay (LOS). Results showed a significant association between use of PIM and increased postoperative mortality and LOS. Study III investigated elderly CRC patients’ experience of healthcare and the information given pre-, peri- and postoperatively. The results showed that feelings of vulnerability, uncertainty, disappointment, loss of control, and exposure were evident during the various phases of surgical care. This was the result of poor information about their cancer and planned treatment, potential impact on daily life and independency, as well as a negative perception of the hospital environment, need for support, and worries about the future. Rehabilitation was perceived as lacking individualisation, and persistent difficulties in regaining appetite and nutritional status prevented a quick recovery. Perception of unclear division of responsibility between care providers was evident after discharge. Study IV investigated if geriatric risk factors identified by a comprehensive geriatric assessment (CGA) performed preoperatively could predict postoperative complications and LOS in elderly patients undergoing CRC surgery. Although no association was seen between the results of individual instruments used in the CGA and postoperative outcome, it was observed that elderly patients tolerated surgery well, and in general regained their preoperative functional status during the follow-up period.Conclusions: Elderly patients are capable of recovering well from elective surgery but there are several areas for improvement. The results revealed age-dependent differences in the surgical care of CRC patients, to the disadvantage of older patients. PIM is associated with worsened outcome and elderly patients perceive the care and information received as lacking individual adaptations. We therefore believe that elderly patients could benefit from a thorough geriatric assessment prior to surgery in order to identify risk patients and adapt and improve peri-operative care in elderly CRC patients.List of scientific papersI. Egenvall M., Schubert Samuelsson K., Klarin I., Lökk J., Sjövall A., Martling, A., Gunnarsson U. Management of colon cancer in the elderly: a population-based study. Colorectal Dis. 2014 Jun;16(6):433-41. https://doi.org/10.1111/codi.12575 II. Schubert Samuelsson K., Egenvall M., Klarin I., Lökk J., Gunnarsson U. Inappropriate drug use in elderly patients is associated with prolonged hospital stay and increased postoperative mortality after colorectal cancer surgery: a population-based study. Colorectal Dis. 2016 Feb;18(2):155-62. https://doi.org/10.1111/codi.13077 III. Schubert Samuelsson K., Iwarzon M., Egenvall M., Klarin I., Lökk J., Gunnarsson U. Elderly peoples’ experiences of health care process and information when undergoing colorectal cancer surgery. [Submitted]IV. Schubert Samuelsson K., Egenvall M., Klarin I., Lökk J., Gunnarsson U. Preoperative geriatric assessment and follow-up of patients 75 years and older undergoing colorectal cancer surgery. [Manuscript]</p
sj-pdf-1-ojs-10.1177_23259671231217725 – Supplemental material for Comparison of Improvement in Patient-Reported Knee Function After Revision and Multiple-Revision ACL Reconstruction Compared With Primary ACL Reconstruction
No full textSupplemental material, sj-pdf-1-ojs-10.1177_23259671231217725 for Comparison of Improvement in Patient-Reported Knee Function After Revision and Multiple-Revision ACL Reconstruction Compared With Primary ACL Reconstruction by Janina Kaarre, Zachary J. Herman, Alberto Grassi, Eric Hamrin Senorski, Volker Musahl and Kristian Samuelsson in Orthopaedic Journal of Sports Medicine</p
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