Pulmonary pressure increases during acute exacerbation in COPD and clinical outcome

BACKGROUND: Elevated pulmonary pressures can lead to right ventricular dysfunction, worsen respiratory status and increase overall morbidity in COPD patients. Yet, little is known about the impact of right-sided pressure changes during acute exacerbation in COPD (AECOPD) on patient outcomes. Our aim was to determine whether pulmonary pressures are elevated during AECOPD compared with the stable phase and to investigate the association between tricuspid regurgitation (TR) gradient during AECOPD and days alive and out of hospital (DAOH).METHODS: This was a multicentre, prospective study of pulmonary pressures changes in patients with AECOPD and stable-phase COPD. Inclusion criteria were diagnosis of COPD and admission with AECOPD. Transthoracic echocardiography (TTE), including TR gradient, tricuspid annular plane systolic excursion (TAPSE), right ventricular diameter and right atrial parameters, was performed during AECOPD and the stable phase.RESULTS: Of 250 patients, 232 underwent TTE during AECOPD and 107 completed stable-phase follow-up. Reasons for incomplete follow-up included death (n=46), withdrawal (n=23), poor TTE quality (n=21) and unmeasurable TR gradients (n=35). TR gradient increased significantly during AECOPD, with a mean difference of 6.0 (95% CI 2.5-9.6) mmHg, while TAPSE, right ventricular diameter and right atrial size showed no significant changes. Higher TR gradients during AECOPD correlated with lower DAOH.CONCLUSION: TR gradients were significantly elevated during AECOPD, suggesting that transient right-sided pressure spikes are associated with COPD exacerbations. However, the direction of this association remains unclear and further research is needed to determine whether right-sided pressure changes contribute to exacerbations or whether exacerbations themselves drive these pressure spikes.</p

Luis Landero: Entrevista

Business confidence is a well-known leading indicator of future output. Whether it has information about future investment is, however, unclear. We determine how informative business confidence is for investment growth independently of other variables using US business confidence survey data for 1955Q1–2016Q4. Our main findings are: (i) business confidence has predictive ability for investment growth; (ii) remarkably, business confidence has superior forecasting power, relative to conventional predictors, for investment downturns over 1–3-quarter forecast horizons and for the sign of investment growth over a 2-quarter forecast horizon; and (iii) exogenous shifts in business confidence reflect short-lived non-fundamental factors, consistent with the ‘animal spirits’ view of investment. Our findings have implications for improving investment forecasts, developing new business cycle models, and studying the role of social and psychological factors determining investment growth

Crosslinked Polymeric Gels as Loss Circulation Materials: An Experimental Study

Abstract In an oil/gas well drilling operation, loss circulation of the drilling fluid in a thief zone is a major problem without a unique solution. This problem is mitigated by using Loss Circulation Materials (LCM). One method to counter this problem could be the use of gel forming polymer systems; that would gel and seal the undesired zones and prevent losses. In this work interaction of a commercial grade hydrolyzed polyacrylamide (HPAM) and a HPAM derivative with polyethleneimine (PEI) was studied, for the possible use of these polymeric systems as a loss preventive and sealing agent. These studies involved the identification of the optimum polymer/crosslinker concentration followed by their thermal stability testing. Dynamic rheology tests were conducted on the systems in order to examine their pre and post-gelation behavior. Differential Scanning Calorimetry (DSC) was used to study the gelation kinetics of the systems. Selected systems were then tested on a see through flow system to observe their performance in a porous media. It was observed that attaining an optimum polymer/crosslinker identification is an essential first step towards attaining a rigid and stable gel. At optimum concentrations stable gels were obtained. Gel strengths were greatly enhanced by increasing temperature and aging time. This was reflected in both the rheology and the DSC tests. The DSC experiments provided great insight into the gelation mechanics of the polymeric LCM systems. For the best two systems, 100% solution to gel conversion was attained in nearly three and a half hours of total ageing time at 100°C isothermal condition. The same gelants when tested on the see-through flow setup were able to successfully prevent mud loss in a zone having 36% porosity and 300 D permeability at room temperature and moderately high pressure conditions. This paper will build on and substantiate the idea of utilizing cross-linked polymer gels as LCM. It will introduce the findings of a self-fabricated see through experimental setup that related the cross-linked polymeric LCM's behavior with differential pressure, in a porous media.</jats:p

Is full colonoscopic examination necessary in young patients with fresh bleeding per rectum?

Background and study aims: Guidelines and practices differ regarding evaluation of young Patients with fresh bleeding per rectum (FBPR). The aim of this study was to determine the frequency and site of endoscopic lesions in young Patients with FBPR, and to thereby determine whether full colonoscopic examination is necessary in these Patients. Methods: Consecutive Patients aged 18-50 years who were scheduled to undergo full colonoscopy for FBPR at Aga Khan University Hospital between May 2007 and October 2009 were enrolled in the study after giving informed consent. FBPR was defined as the passing of fresh blood per rectum with or without stools and/or noticing blood in the toilet bowl. Lesions were characterized as proximal or distal to the splenic flexure. Patients with positive family history of colorectal cancer, bleeding requiring blood transfusion, bleeding diathesis, or iron deficiency anemia were excluded. Results: A total of 379 Patients met the inclusion criteria and were analyzed. Of these, 248 Patients (65.4%) were under 40 years of age and 131 (34.6%) were aged 40-50 years. Mean hemoglobin was 12.93 +/- 1.78 g/dL. In Patients \u3c 40 years, seven (2.8%) adenomatous polyps and malignant lesions were found, all of which were located in the distal colon. In Patients aged 40-50 years, 10 (7.6%) adenomatous polyps and malignant lesions were detected, one of which was located in the proximal colon. On univariate analysis, malignant and adenomatous lesions were significant in the 40-50 years age group (P = 0.031, OR, 2.84, 95% CI 1.05-7.65). Conclusion: Endoscopic lesions in Patients younger than 40 years with FBPR are found mostly in the distal colon and hence flexible sigmoidoscopy seems to be a reasonable evaluation tool in young Patients with no other alarm symptoms

An automated context-aware IoT vulnerability assessment rule-set generator

While introducing unprecedented applications, Internet of Things (IoT) has simultaneously provoked acute security challenges, in the form of the vulnerabilities. Mainly because manufacturers overlook the security considerations and produce devices that could be exploited easily. Security systems used for the protection of IoT environment usually deploy traditional rulesets which lack distinct IoT vulnerability assessment elements and therefore are inadequate for providing security to IoT eco-system. Hence, due to the variety and volume of such devices, traditional security solutions need to be more robust for IoT settings. Contrary to the traditional rule-set, IoT device vulnerability identification requires distinct understanding of IoT-specific vulnerability vectors, based on their architecture, resource constrained nature, communication primitives and context awareness. This research work has proposed an automated context-aware IoT vulnerability assessment rule-set framework. Proposed system dynamically identifies IoT devices along with the services running on them, gathers their respective vulnerabilities, transform them into rules and enforce them into the security solutions. The proposed framework has been evaluated on a dataset of 49 IoT devices. According to the results, proposed framework automatically generated rules against all the vulnerabilities present in the network under consideration. Additionally, this research has proposed IoT vulnerability assessment rule-set elements which are necessary to be considered while designing any IoT vulnerability assessment rule-set. With the proposed mechanism, this research work intends to fill the missing lines of defense against rising IoT vulnerabilities. The proposed framework will benefit researchers, security analysts and manufacturers to devise reliable IoT security solutions

Flowing Gels for Loss Circulation Prevention

Abstract Loss circulation is a common problem in drilling operations. It is a problem in which not only the valuable drilling fluid is lost, but also time and money accompany those losses. In order to mitigate this problem various loss circulation materials (LCMs) are being used all over the world. Among those LCMs are crosslinked polymer gel systems. In this work, a polymeric LCM system was studied for its potential use as a loss prevention material. The system studied is composed of polyacrylamide (PAM), phenol and formaldehyde as the main components. Under certain temperature and mixing conditions, their interaction constitutes a strong flowing gel. To study the effectiveness of the system, the gel was tested into a self-fabricated see through flow apparatus to study the effectiveness of the gel system in preventing mud losses under different permeability conditions. The crosslinked polymeric gel system was tested under three different permeability conditions. It was observed that the gel system was effectively able to prevent losses in two of those porous media at room temperature and moderately high-pressure conditions. Of these, the least permeable thief zone had a porosity of 36% and a permeability of 300 D. The same porous media was selected to study the behavior of the gel with respect to time. For this experiment a bulk volume of the gel was prepared and left static in the LCM displacement vessel. The flow experiment was conducted at three different timelines. It was observed that with the passage of time the gel system gets denatured but still remains relatively effective. This paper will highlight and add to the usage of crosslinked organic polymer gelants as LCMs. It will present the findings of an in-house see through flow setup that was used to study the effectiveness of the LCM in relation to the differential pressure across the loss zone.</jats:p