Structural diagenetic attributes of the late Cretaceous Williams fork sandstones with implications for petrophysical interpretation and fracture prediction, Piceance Basin, Colorado

textDiagenetic and structural aspects of tight gas sandstones must be addressed concurrently in order to fully understand low-permeability sandstones and to better predict their reservoir quality attributes that arise from a combination of pore-scale and fracture distribution characteristics. This dissertation focuses on aspects of rock evolution that are germane to concurrent structural and diagenetic evolution, such as loading and thermal history, rock mechanical property evolution, and fracture timing. I tested the hypothesis that the cement precipitation step, governed by thermal exposure and grain surface attributes, governs how sandstone attributes evolve using observations from the Late Cretaceous Williams Fork sandstones from the Piceance Basin, Colorado. My research shows that essential information for predicting and understanding fracture patterns in sandstone can be obtained by unraveling cement precipitation (diagenetic) history. Fractures depend on the mechanical properties existing during fracture growth. I show that key rock mechanical properties (subcritical crack index, Young's modulus and Poisson's ratio), petrophysical behavior, and reservoir quality depend in a systematic way on time-temperature history and the intrinsic grain surface attributes of these sandstones. I classified the Williams Fork lithofacies petrographically and correlated those with log responses to create a model that can be used to predict reservoir quality and diagenesis directly from well logs. I determined rock mechanical characteristics by measuring the subcritical crack index (SCI), a mechanical property that influences fracture distribution characteristics, and by examining log-derived bulk mechanical properties. To quantify the influence of quartz cementation on the SCI and to determine the range of SCI values for sandstone of given framework composition at different diagenetic stages, I measured SCI on Williams Fork core samples and their outcrop equivalents. Diagenetic modeling is applied to determine the sandstone characteristics during fracturing.Geological Science

Quartz types, authigenic and detrital, in the Upper Cretaceous Eagle Ford Formation, South Texas, USA

Lithologic heterogeneity of the Eagle Ford Formation in South Texas arises from mixing of extrabasinal grains of siliciclastic composition with intrabasinal grain assemblages composed dominantly of marine carbonate with a lesser component of biosiliceous debris. Detrital quartz in particular is derived from both extrabasinal and intrabasinal sources, posing a challenge for the use of bulk compositional data for mudrock classification. Extrabasinal detrital quartz supplied along a major axis of siliciclastic influx, the Woodbine depositional system of East Texas, is reduced to a minor part of the grain assemblage in South Texas. Petrographic evidence and point count results indicate that around 85 percent of total quartz in these rocks, equal to about 12.6 volume percent, is authigenic. Thus, significant quantities of authigenic silica are not restricted to siliceous mudrocks, but can be found in carbonate-rich mudrocks as well. Formerly opaline skeletons of radiolaria, the dominant source of silica for authigenic quartz precipitation, are only poorly preserved by replacements including calcite, dolomite, pyrite, and quartz. Dissolved silica released by dissolution of radiolarians, and perhaps also by volcanic glass dissolution is re-precipitated in a variety of forms, including matrix-dispersed microquartz cement, fillings within primary intragranular pores, and grain replacement of both calcareous and siliceous allochems. The mass balance of dissolved silica mobilized from radiolarians and other reactive silicates and the precipitation of authigenic quartz is uncertain because the initial volumes of now-dissolved detrital material versus the final volume of authigenic material (quartz and other authigenic silicates) cannot be determined with accuracy

Inhibition of the Notch Pathway Promotes Flap Survival by Inducing Functional Neoangiogenesis

WOS: 000361609000019PubMed ID: 25180956Objective The Notch pathway seems to function as an antiangiogenic factor, negatively regulating the sprouting effect of vascular endothelial growth factor (VEGF). This function is well defined in embryonic and tumor vasculature. However, little is known about its function in ischemia-induced angiogenesis. In the first part of this study, we investigated the role of Notch in reparative angiogenesis after ischemia. In the second part, we hypothesized that anti-Notch therapy will result in increased angiogenic sprouting. We analyzed the effect of Notch inhibition in the induction of angiogenic sprouting. Methods In the first part, we investigated the effect of ischemia on the Notch ligand delta-like ligand 4 (DLL4). Twenty rats were divided equally into 2 groups. In the surgery group, dorsal skin flap was used as model of ischemia. In the control group, no surgical procedure was performed. DLL4 and VEGF gene expressions were assessed. Immunohistochemical staining was used for detection of DLL4 in tissue materials. Plasma levels of VEGF and DLL4 were measured. In the second part, we investigated the effect of Notch inhibition using a gamma-secretase inhibitor (GSI) on inducing neoangiogenesis. Twenty rats were assigned to 2 equal groups. In all animals, dorsal skin flap was raised and sutured back into its bed. Animals in the GSI-treated group received GSI intravenously after surgery for 3 days. Saline was administered in the control group. Necrotic area measurements, microangiography, and histologic evaluations were performed to compare groups. Results In the first part, VEGF and DLL expressions increased in ischemic tissues (P < 0.01). Immunohistochemical analysis revealed that DLL4 expression was upregulated in capillary endothelial cells after ischemia. Plasma levels for VEGF and DLL4 were higher in the animals that underwent surgery (P < 0.01). In the second part, GSI treatment resulted in higher flap survival rates (P < 0.05). Microscopic analysis exhibited increase in the number of microvascular structures after GSI treatment (P < 0.05). Microangiographic evaluation showed that neovascularization increased in the GSI-applied flaps. Conclusions We present an evidence for the importance of the Notch pathway in the regulation of ischemia-induced angiogenesis. Notch inhibition promotes flap survival by creating a neovasculature that has an increase in vascular density

Familial Mediterranean Fever Mutation Analysis in Pediatric Patients With Inflammatory Bowel Disease: A Multicenter Study

Background: the aim of the study was to evaluate familial Mediterranean fever (FMF) mutation analysis in pediatric patients with inflammatory bowel disease (IBD). The relation between MEFV mutations and chronic inflammatory diseases hos been reported previously

Turkish registry for diagnosis and treatment of acute heart failure: TAKTIK study

WOS: 000392634300003PubMed ID: 28045409Objective: The goal of this study was to develop a national database of patients hospitalized in Turkey with acute heart failure (AHF) using evaluations of diagnostic and therapeutic approaches. Methods: Patient data were collected using an Internet-based survey. A total of 588 patients were enrolled from 36 participating medical centers across the country. Results: Mean age was 62 +/- 13 years and 38% of the patients were female. Ratio of de novo AHF to study cohort was 24%. Coronary heart disease and hypertension were found in 61% and 53% of the patients, respectively. Valvular heart disease was the underlying cause in 46% of heart failure patients. The most frequent factor associated with decompensation was noncompliance with treatment, observed in 34% of patients. Systolic blood pressure was 125 +/- 28 mmHg and heart rate was 93 +/- 22 beats/minute in the cohort. The most common findings on physical examination were inspiratory fine crackles (84%), peripheral edema (64%), and cold extremities in 34%. Mean ejection fraction (EF) measured at admission was 33 +/- 13%. Preserved EF (>=%40) was present in 20% of patients. On admission, 60%, 46%, and 40% of patients were using angiotens-in-converting enzyme inhibitor/angiotensin receptor blocker, beta-blocker, or aldosterone antagonist, respectively. In-hospital events were reported as 3.4% death, 1.6% stroke and 2% myocardial infarction. Conclusion: Compared to previous data collected around the world, AHF patients in Turkey were younger, had more frequently valvular heart disease as the underlying cause, and were more noncompliant with medical treatment, but overall mortality was lower. Drugs shown to reduce mortality, and which also form the basis of guideline-directed medical therapy, are still used inadequately.Turkish Society of CardiologyTurkish Society of Cardiolog

The Frequency of Lysosomal Acid Lipase Deficiency in Children With Unexplained Liver Disease

Objectives: Evidence suggests that lysosomal acid lipase deficiency (LAL-D) is often underdiagnosed because symptoms may be nonspecific. We aimed to investigate the prevalence of LAL-D in children with unexplained liver disease and to identify demographic and clinical features with a prospective, multicenter, cross-sectional study