16 research outputs found
Informationの多変数解析への応用について
The Paleocene–Eocene Thermal Maximum (PETM), at ca. 55.8 Ma, is one of the most studied instances of past greenhouse gas-induced global warming. As such, it provides a rich opportunity to examine the impact of such global change on local climates. The effects of increased continental and sea surface temperatures on local precipitation and humidity during the PETM remain poorly constrained and studies reveal complex, regional differences; whilst some localities appear to experience a net increase in humidity, others exhibit the opposite. Crucially, there are few records of hydrological change from tropical regions. Recent onshore drilling expeditions in Tanzania have yielded expanded sedimentary sections, deposited in a marine environment, that span much of the Late Cretaceous and Paleogene and show exceptionally good preservation of both calcareous microfossils and organic matter. The PETM interval has previously been constrained by both biostratigraphy and carbon isotopic records and spans ca. 7 m of section. Lipid distributions, including various terrestrial, marine and bacterial biomarkers and their hydrogen isotopic compositions, as well as mineralogy, were used to examine East African vegetation and hydrological responses to the global change occurring at the PETM. Although total organic carbon contents decrease, the concentrations of both higher plant (n-alkanes, n-alkanoic acids) and soil bacterial (glycerol dialkyl glycerol tetraethers) biomarkers increase dramatically at the onset of the PETM negative carbon isotope excursion (CIE), suggesting an increased discharge of fluvial sedimentary organic matter. Similarly, mineralogical indicators of terrestrial input – including Ti/Al and Si/Al ratios, quartz contents and, notably, the proportion of kaolinite – also increase at the onset of the CIE. However, higher plant leaf wax n-alkanes (C27, C29 and C31) become more deuterium-enriched throughout the same interval, suggesting a more arid and/or hotter, rather than a more humid, environment. This evidence collectively suggests an East African early PETM climate characterised by overall hot and arid conditions punctuated by intense, perhaps seasonal, precipitation events. These data match observations from other locations at mid-latitudes, suggesting that the humid climate often suggested for the PETM was not globally widespread
Adipose-derived stem cells in novel approaches to breast reconstruction: their suitability for tissue engineering and oncological safety
Adipose-derived stem cells (ADSCs) are rapidly becoming the gold standard cell source for tissue engineering strategies and hold great potential for novel breast reconstruction strategies. However, their use in patients with breast cancer is controversial and their
oncological safety, particularly in relation to local disease recurrence, has been questioned. In vitro, in vivo, and clinical studies using ADSCs report conflicting data on their suitability for adipose tissue regeneration in patients with cancer. This review aims to provide an overview of the potential role for ADSCs in breast reconstruction and to examine the evidence relating to the oncologic safety of their use in patients with breast
cancer
Dielectric characterization of ex vivo ovine and human adrenal glands for microwave thermal ablation applications
Historically, adrenal glands diseases causing hypertension, such as Primary Aldosteronism (PA), have been treated through pharmacotherapy or surgical resection. Given the shortcomings of the available treatment options, the interest in alternative and less invasive treatment modalities such as microwave ablation (MWA), has increased. In order to develop and optimize this novel electromagnetic-based therapy, an accurate knowledge of the dielectric properties of human adrenal glands, as well as preclinical animal models, is crucial. In particular, ovine models represent a feasible animal model to test the safety and performances of MWA. In this study, the dielectric properties of ovine adrenal glands and of normal and diseased human adrenal glands are characterized ex vivo in the microwave frequency range. The dielectric properties of the two functional tissues (cortex and medulla) composing ovine adrenal glands are measured using the open-ended coaxial probe technique and represented with a two pole Cole-Cole model in the frequency range from 0.5 GHz to 8 GHz. This paper presents the first dielectric data of normal and diseased human adrenal tissues, including a functioning adenoma responsible for PA and it compares the human data with data from the animal model.peer-reviewe
Lipid lowering therapy, low-density lipoprotein level and risk of intracerebral hemorrhage – a meta-analysis
The association of lipid lowering therapy and intracerebral hemorrhage risk is controversial.
We performed a cumulative meta-analysis of lipid lowering trials that reported intracerebral hemorrhage. Statin, fibrate, ezetimibe, PCSK9, and CETP trials were included. We explored whether the association of lipid lowering therapy and risk of intracerebral hemorrhage may vary by baseline low-density lipoprotein (LDL) level, mean change in LDL or baseline cardiovascular risk of population.
Among 39 trials (287,651 participants), lipid lowering therapy was not associated with a statistically significant increased risk of intracerebral hemorrhage (ICH) in primary and secondary prevention trials combined (odds ratio [OR], 1.12; 95% confidence interval [CI], .98-1.28). Lipid lowering was associated with an increased risk of ICH in secondary prevention trials (OR, 1.18; 95% CI, 1.00-1.38), but not in primary prevention trials (OR, 1.01; 95% CI, .78-1.30), but the test for interaction was not significant (P for interaction¿=¿.31). Meta-regression of baseline LDL or difference in LDL reduction between active and control did not explain significant heterogeneity between studies for ICH risk. Of 1000 individuals treated for 1 year for secondary prevention, we estimated 9.17 (95% CI, 5.78-12.66) fewer ischemic strokes and .48 (95% CI, .06-1.02) more ICH, and a net reduction of 8.69 in all stroke per 1000 person-years.
The benefits of lipid lowering therapy in prevention of ischemic stroke greatly exceed the risk of ICH. Concern about ICH should not discourage stroke clinicians from prescribing lipid lowering therapy for secondary prevention of ischemic stroke.peer-reviewed2020-03-1
Lipid lowering therapy, low-density lipoprotein level and risk of intracerebral hemorrhage – a meta-analysis
The association of lipid lowering therapy and intracerebral hemorrhage risk is controversial.
We performed a cumulative meta-analysis of lipid lowering trials that reported intracerebral hemorrhage. Statin, fibrate, ezetimibe, PCSK9, and CETP trials were included. We explored whether the association of lipid lowering therapy and risk of intracerebral hemorrhage may vary by baseline low-density lipoprotein (LDL) level, mean change in LDL or baseline cardiovascular risk of population.
Among 39 trials (287,651 participants), lipid lowering therapy was not associated with a statistically significant increased risk of intracerebral hemorrhage (ICH) in primary and secondary prevention trials combined (odds ratio [OR], 1.12; 95% confidence interval [CI], .98-1.28). Lipid lowering was associated with an increased risk of ICH in secondary prevention trials (OR, 1.18; 95% CI, 1.00-1.38), but not in primary prevention trials (OR, 1.01; 95% CI, .78-1.30), but the test for interaction was not significant (P for interaction¿=¿.31). Meta-regression of baseline LDL or difference in LDL reduction between active and control did not explain significant heterogeneity between studies for ICH risk. Of 1000 individuals treated for 1 year for secondary prevention, we estimated 9.17 (95% CI, 5.78-12.66) fewer ischemic strokes and .48 (95% CI, .06-1.02) more ICH, and a net reduction of 8.69 in all stroke per 1000 person-years.
The benefits of lipid lowering therapy in prevention of ischemic stroke greatly exceed the risk of ICH. Concern about ICH should not discourage stroke clinicians from prescribing lipid lowering therapy for secondary prevention of ischemic stroke.peer-reviewed2020-03-1
The Eocene−Oligocene transition in Nanggulan, Java:lithostratigraphy, biostratigraphy and foraminiferal stable isotopes
Stratigraphy and sedimentology of the Upper Cretaceous to Paleogene Kilwa Group, southern coastal Tanzania
The geology of southern coastal Tanzania has remained poorly understood since the first comments on its stratigraphy were made
over 100 years ago. However, new field surveys combined with shallow drilling along the coast between Kilwa and Lindi are beginning
to resolve the depositional history and structural evolution of this region over the past 85 Ma. Here we present the first attempt to synthesize
the results of these studies to provide a coherent sedimentological, litho- and sequence stratigraphic framework, including new
geological maps, for the Upper Cretaceous and Paleogene of the coastal zone.
Santonian to Oligocene sediments crop out along a broad coastal belt south of the Rufiji River from the Kilwa peninsula to Lindi
Creek in southern Tanzania. During �55 Ma, over 1 km of a broadly homogeneous, mid to outer shelf clay-dominated succession
was deposited across the passive margin, which we define here as the Kilwa Group. This lies disconformably across the shelf on Albian
marls and is itself unconformably overlain by shallow water Miocene clays and more recent limestones, sands and gravels. Four formations
can be identified within the Kilwa Group on the basis of characteristic secondary lithologies and facies, described here for the first
time; the Nangurukuru, Kivinje, Masoko and Pande Formations. These formations include conformable stratigraphic intervals through
both the Paleocene–Eocene and Eocene–Oligocene boundaries. Within the Kilwa Group, 12 sequence stratigraphic cycles can be identified
at present, demonstrating relatively uniform and continual subsidence across the margin from Santonian to Early Oligocene time.
A further major bounding surface is present between the Upper Cretaceous and Paleogene, but this may become partly conformable in
the Lindi area. Although the principal lithology in all formations is clay or claystone, there are more permeable intervals containing pervasive
coarser siliciclastic sediments and these have yielded traces of crude oil which is likely to have migrated from lower in the succession.
The Kilwa Group thus also provides important new evidence for petroleum play development in the southern coastal zone