Digital and experimental rock analysis of proppant injection into naturally fractured coal

Proppant-laden fluid injection has been applied to many low permeability reservoirs, such as coal seams, to enhance permeability and thus production. While there are several laboratory-scale experimental studies on proppant placement in hydraulic fractures, the possible infiltration of proppant into natural fractures and its effect on overall permeability has received little attention. We study proppant injection into a naturally fractured coal sample by a combination of experimental and digital rock technologies. The sample was imaged using a helical X-ray computed tomography (micro-CT) scanner in as-received condition. Then, proppants of different size ranges were gradually injected into the sample, using a purpose-built X-ray transparent core flooding system, and the permeability was measured at different effective stresses. Subsequently, the propped sample was re-imaged and registered to the as-received image to map the internal changes. The experimental results indicated almost no permeability change of the sample after proppant injection. While proppant collection in the outlet proved passage of the proppant through the sample, observation of the sample indicated that some of the proppants were accumulated on the inlet face of the core and created a filter leading to no permeability increment. Micro-CT images confirmed that proppants were effectively placed in the sample and kept the fractures open. Numerical computation of permeability, using the digital coal sample in which accumulated proppants at the coal surface were excluded, indicated a significant increase in the sample permeability. Such an increase resulted from the opening of the fractures, particularly in the outlet region. This demonstrated the significance of proppant size selection for coal seam hydraulic fracturing. While proppants were successfully placed in the fractures, the experiment measured the permeability of the system, including proppants accumulated on the inlet, and could not effectively map the internal changes. This, therefore, needs to be considered when an experimental program for proppant injection is executed. To accurately monitor the internal changes, application of digital rock technology is recommended for such experiments

Microbiologically influenced corrosion of cable bolts in underground coal mines: The effect of Acidithiobacillus ferrooxidans

Reports on corrosion failure of cable bolts, used in mining and civil industries, have been increasing in the past two decades. The previous studies found that pitting corrosion on the surface of a cable bolt can initiate premature failure of the bolt. In this study, the role of Acidithiobacillus ferrooxidans (A. ferrooxidans) bacterium in the occurrence of pitting corrosion in cable bolts was studied. Stressed coupons, made from the wires of cable bolts, were immersed in testing bottles containing groundwater collected from an underground coal mine and a mixture of A. ferrooxidans and geomaterials. It was observed that A. ferrooxidans caused pitting corrosion on the surface of cable bolts in the near-neutral environment. The presence of geomaterials slightly affected the pH of the environment; however, it did not have any significant influence on the corrosion activity of A. ferrooxidans. This study suggests that the common bacterium A. ferrooxidans found in many underground environments can be a threat to cable bolts’ integrity by creating initiation points for other catastrophic failures such as stress corrosion cracking

Eltrombopag for the treatment of immune thrombocytopenia: The aegean region of Turkey experience

Objective: Immune thrombocytopenia (ITP) is an immune-mediated disease characterized by transient or persistent decrease of the platelet count to less than 100x109/L. Although it is included in a benign disease group, bleeding complications may be mortal. With a better understanding of the pathophysiology of the disease, thrombopoietin receptor agonists, which came into use in recent years, seem to be an effective option in the treatment of resistant cases. This study aimed to retrospectively assess the efficacy, long-term safety, and tolerability of eltrombopag in Turkish patients with chronic ITP in the Aegean region of Turkey. Materials and Methods: Retrospective data of 40 patients with refractory ITP who were treated with eltrombopag in the Aegean region were examined and evaluated. Results: The total rate of response was 87%, and the median duration of response defined as the number of the platelets being over 50x109/L was 19.5 (interquartile range: 5-60) days. In one patient, venous sinus thrombosis was observed with no other additional risk factors due to or related to thrombosis. Another patient with complete response and irregular follow-up for 12 months was lost due to sudden death as the result of probable acute myocardial infarction. Conclusion: Although the responses to eltrombopag were satisfactory, patients need to be monitored closely for overshooting platelet counts as well as thromboembolic events. © 2015 Turkish Society of Hematology. All rights reserved

Efficient delivery of RNA Interference to peripheral neurons in vivo using herpes simplex virus

Considerable interest has been focused on inducing RNA interference (RNAi) in neurons to study gene function and identify new targets for disease intervention. Although small interfering RNAs (siRNAs) have been used to silence genes in neurons, in vivo delivery of RNAi remains a major challenge limiting its applications. We have developed a highly efficient method for in vivo gene silencing in dorsal root ganglia (DRG) using replication-defective herpes simplex viral (HSV-1) vectors. HSV-mediated delivery of short-hairpin RNA (shRNA) targeting reporter genes resulted in highly effective and specific silencing in neuronal and non-neuronal cells in culture and in the DRG of mice in vivo including in a transgenic mouse model. We further establish proof of concept by demonstrating in vivo silencing of the endogenous trpv1 gene. These data are the first to show silencing in DRG neurons in vivo by vector-mediated delivery of shRNA. Our results support the utility of HSV vectors for gene silencing in peripheral neurons and the potential application of this technology to the study of nociceptive processes and in pain gene target validation studies

Management of Septated Malignant Pleural Effusions

Purpose of Review: We review recent studies of patients with septated malignant pleural effusions, to understand what the clinical implications for patients are and what evidence-based methods should be used to manage these effusions. Recent Findings: Fibrinolytics improve effusion size assessed radiologically in patients with a chest drain inserted for septated malignant pleural effusions but this does not translate into an improvement in breathlessness relief or pleurodesis success. Fibrinolytics have also been used in patients with septated effusions associated with indwelling pleural catheters, but dyspnoea relief has not been assessed in this population. Patients with septated effusions or extensive adhesions appear to have a worse prognosis. Summary: Patients with septated malignant pleural effusions have a poor prognosis and do not gain clinical benefit from fibrinolytics via chest drain. The role of fibrinolytics for septated effusions associated with indwelling pleural catheters requires further study

Lot quality survey: an appealing method for rapid evaluation of vaccine coverage in developing countries – experience in Turkey

<p>Abstract</p> <p>Background</p> <p>Vaccine-preventable diseases cause significant morbidity and mortality worldwide and in developing countries in particular. Information on coverage and reasons for non-vaccination is vital to enhance overall vaccination activities. Of the several survey techniques available for investigating vaccination coverage in a given setting, the Lot Quality Technique (LQT) remains appealing and could be used in developing countries by local health personnel of district or rural health authorities to evaluate their performance in vaccination and many other health-related programs. This study aimed to evaluate vaccination coverage using LQT in a selected semi-urban setting in Turkey.</p> <p>Methods</p> <p>A LQT-based cross-sectional study was conducted in Kecioren District on a representative sample of residents aged 12–23 months in order to evaluate coverage for routine childhood vaccines, to identify health units with coverage below 75%, and to investigate reasons for non-vaccination.</p> <p>Results</p> <p>Based on self-reports, coverage for BCG, diphtheria-pertussis-tetanus (DPT-3), oral polio-3, hepatitis-3, and measles vaccines ranged between 94–99%. Coverage for measles was below 75% in five lots. The relatively high educational and socioeconomic status of parents in the study group alone could not minimize the "considerable" risk of vaccine-preventable diseases in the District and dictates a continuity of efforts for improving vaccination rates, with special emphasis on measles. We believe that administrative methods should be backed up by household surveys to strengthen vaccination monitoring and that families should be trained and motivated to have their children fully vaccinated according to the recommended schedule and in a timely manner.</p> <p>Conclusion</p> <p>This study identified vaccine coverage for seven routine vaccines completed before the age of 24 months as well as the areas requiring special attention in vaccination services. The LQT, years after its introduction to health-related research, remains an appealing technique for rapid evaluation of the extent of a variety of local health concerns in developing countries, in rural areas in particular, and is very efficient in determining performance of individual subunits in a given service area. Training of local health personnel on use of the LQT could expedite response to local health problems and could even motivate them in conducting their own surveys tailored to their professional interests.</p

Presence of factors that activate platelet aggregation in mitral stenotic patients' plasma

BACKGROUND: Although the association between mitral stenosis (MS) and increased coagulation activity is well recognized, it is unclear whether enhanced coagulation remains localized in the left atrium or whether this represents a systemic problem. To assess systemic coagulation parameters and changes in platelet aggregation, we measured fibrinogen levels and performed in vitro platelet function tests in plasma obtained from mitral stenotic patients' and from healthy control subjects' peripheral venous blood. METHODS: Sixteen newly diagnosed patients with rheumatic MS (Group P) and 16 healthy subjects (Group N) were enrolled in the study. Platelet-equalized plasma samples were evaluated to determine in vitro platelet function, using adenosine diphosphate (ADP), collagen and epinephrine in an automated aggregometer. In vitro platelet function tests in group N were performed twice, with and without plasma obtained from group P. RESULTS: There were no significant differences between the groups with respect to demographic variables. Peripheral venous fibrinogen levels in Group P were not significantly different from those in Group N. Adenosine diphosphate, epinephrine and collagen-induced platelet aggregation ratios were significantly higher in Group P than in Group N. When plasma obtained from Group P was added to Group N subjects' platelets, ADP and collagen-induced, but not epinephrine-induced, aggregation ratios were significantly increased compared to baseline levels in Group N. CONCLUSION: Platelet aggregation is increased in patients with MS, while fibrinogen levels remain similar to controls. We conclude that mitral stenotic patients exhibit increased systemic coagulation activity and that plasma extracted from these patients may contain some transferable factors that activate platelet aggregation

Monophasic synovial sarcoma of the pharynx: a case report

Synovial sarcomas are a rare form of soft tissue sarcomas. We present a case of a 62 year-old male presenting with a left thyroid lump initially though to be a thyroid adenoma but subsequently diagnosed as a monophasic synovial sarcoma of the pharynx. We discuss the diagnosis and treatment of this case