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  • Author: Andrei Bogdan x
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Abstract

Pounding effects during earthquake is a subject of high significance for structural engineers performing in the urban areas. In this paper, two ways to account for structural pounding are used in a MATLAB code, namely classical stereomechanics approach and nonlinear viscoelastic impact element. The numerical study is performed on SDOF structures acted by ELCentro recording. While most of the studies available in the literature are related to Newmark implicit time integration method, in this study the equations of motion are numerical integrated using central finite difference method, an explicit method, having the main advantage that in the displacement at the ith+1 step is calculated based on the loads from the ith step. Thus, the collision is checked and the pounding forces are taken into account into the equation of motion in an easier manner than in an implicit integration method. First, a comparison is done using available data in the literature. Both linear and nonlinear behavior of the structures during earthquake is further investigated. Several layout scenarios are also investigated, in which one or more weak buildings are adjacent to a stiffer building. One of the main findings in this paper is related to the behavior of a weak structure located between two stiff structures.

Abstract

Chronic lymphocytic leukemia (CLL) has a heterogeneous clinical course. Among useful markers in identifiyng patients with poor outcome are unmutated IgVH, ZAP-70 and CD38 expression. Both ZAP-70 and CD38 were shown to be capable of identifying aggressive CLL.

We analysed data from 35 patients diagnosed with CLL based on morphological and immunophenotypical criteria. In all cases peripheral blood immunophenotyping was performed as initial diagnostic test. Immunohistochemical expression of ZAP-70 and CD38 was evaluated on 21 cases of lymph node biopsies and 14 cases of bone marrow biopsies, performed at the time of diagnosis. In addition in-situ hybridization for EBER-1 was evaluated.

The median age of patients was 60 years and we noted a slight male predominance. The immunophenotypic criteria (C23+, CD5+, CD20+, CD10-, CD3-, cyclinD1-) for B-cell CLL were achieved in all 35 patients. We found that CLL cases showing expression of both markers (ZAP-70+CD38+ patients) are characterised by an unfavourable clinical course as compared with cases that did not show expression of markers (ZAP-70-CD38- patients). Our data showed significant differences in terms of overall survival at 5 years between the two groups. We also found statistically significant differences between patients ZAP-70-CD38- and patients with one or both positive markers (ZAP-70+ and/or CD38+).

Prognostic information given by ZAP-70 and CD38 could be used in guiding treatment decisions and they probably should be recommended to all patients with B-CLL in trying to obtain a more clear profile of the disease at the time of diagnosis.

Abstract

Background. Endoscopic retrograde cholangiopancreatography has evolved significantly in recent years. The increase in complexity and range of applications has not been adequately reflected in an improvement of training methods for ERCP, with many endoscopists failing to meet required performance standards during their training period and limited available data on their performance immediately after completing training. We aimed to analyze the performance of an independent operator from a developing country after the completion of formal training with regard to procedure and patient-related outcomes.

Methods. We conducted an observational study of ERCPs performed by a young endoscopist from a referral center. Data about the procedure, cannulation technique (including use of precut), trainee involvement and procedure-related outcomes was retrieved and analyzed from a prospectively maintained database on quality in ERCP (the QUASIE initiative).

Results. Data from 679 consecutive ERCPs conducted or supervised by one endoscopist with < 200 independent procedures prior to the study period were included in the final analysis. Cannulation rates significantly improved over time, from 90% to 96% (p = 0.016). Use of precut techniques changed significantly over time, with an initial increase followed by a subsequent decrease as overall cannulation rates improved. Trainee involvement was significantly associated with prolonged cannulation times (p = 0.003) and use of precut (p = 0.001), but did not impact on technical success or patient safety.

Conclusions. Independent practice of ERCP after the training period is characterized by ongoing changes in technique, especially with regard to cannulation and use of precut, showing significant improvements in performance over time.

Abstract

Background and aims. Selective cannulation of the desired duct is a key element in ERCP procedures and an important step in the training of fellows. However, there is limited data about technical success and patient safety for ERCPs conducted in a training setting.We aimed to evaluate the impact of trainee involvement on the cannulation technique and procedure related outcomes at ERCP.

Materials and methods. We conducted an observational study of all ERCP conducted in an endoscopy unit with an on-going training program. Patient related data and procedure-related data (method of cannulation, time to cannulation, degree of trainee involvement, technical success and procedure-related adverse events) were collected using a standard form. The method of cannulation, time to cannulation and procedure-related adverse events were compared between ERCPs with trainee involvement and those without.

Results. 641 consecutive ERCPs were evaluated and 474 native papilla cases performed by 4 trainers and 3 trainees were included in the final analysis. Trainees were involved in 171 procedures (36.1%), achieving cannulation of the desired duct in 50.8% of the cases. Cannulation rates were similar in the trainee group compared to the control group (91.7% vs. 88.7%) and there was no increase in the rate of adverse events. However, cannulation time was significantly longer in the trainee group with a significant increase in the rate of precut use (32.1% vs. 23.4%, p < 0.001).

Conclusions. Trainee involvement resulted in longer cannulation times and increased use of precut sphincterotomy, but, was not associated with an increased risk of procedure related adverse events.

Abstract

In this paper we analyse the monetary policy of the National Bank of Romania during 2005-2015 by estimating the Taylor rule, on a quarterly basis. We determined the potential GDP by employing the Hodrick-Prescott filter, in order to distinguish between the cyclical and the structural components of the output. Then, we estimated the traditional Taylor rule function (with a classic OLS regression), but slightly modified, as to take into account the forward-looking attitude of the NBR. The results confirm the direct correlation between the monetary policy rate and the output gap on the one hand, and the inflation differential (inflation - inflationtarget) on the other hand. Also, the results show us that NBR paid a higher attention to the dynamics of the inflation versus its target than to the output gap. Last, but not least, the central bank has been also sensitive to the financial stability, as reflected by the results of the incorporation of the ROBOR-EURIBOR spread in the classical Taylor rule.

Abstract

Introduction: Myxofibrosarcoma is a rare subtype of soft tissue sarcoma with a locally infiltrative behavior and ability to determine distant metastases.

Materials and methods: We presented two myxofibrosarcoma cases who benefited from segmental or radical resection.

Management and outcome: In the case of the 80-year-old woman, with grade 3 myxofibrosarcoma, we practiced radical surgery with scapulohumeral disarticulation followed by adjuvant radiotherapy.

The therapeutic option for the 77-year-old man with grade 2 myxofibrosarcoma was segmental resection followed by adjuvant radiotherapy. After three months, the patient was in a good clinical condition with no sign of local recurrence, but with the presence of pulmonary metastases for the patient who benefited of segmental resection.

Discussion: The radical resection had better short-term results, with no local or distant metastases at three months after surgery, although the tumor had a higher grade (G3), compared to segmental resection practiced for a lower grade tumor (G2), in which case the patient developed pulmonary metastasis at three months follow up.

Conclusion: Myxofibrosarcoma represents a challenging situation regarding the management due to its unpredictive clinical course. Our cases raised the following question: should we consider treating it more aggressively in order to obtain good local control and reduce the risk of metastasis?

Abstract

Lung cancer is the main cause of cancer death both in men and women. In spite of progress seen in the early diagnosis of lung cancer, and implementation of new treatment principles for these patients, 5 year survival of non-small cell lung cancer patients undergoing surgery is low. Introduction of anti-angiogenic therapy administered concomitantly with conventional chemotherapy agents represented practically the first success seen in the treatment of lung cancer in the last 20 years. The aim of this paper is to review the literature informations about the importance of VEGF (vascular endothelial growth factor) as a marker of angiogenesis in patients with non-small cell lung cancer. Therefore, we practiced a literature review about these topics: the importance of VEGF in tumor angiogenesis and lymphangiogenesis in patients with non-small cell lung cancer and his importance as a prognostic factor at these patients, the prognostic impact of serum levels of VEGF and of the cellular expression of VEGF at these patients and also we reviewed the value of the antiangiogenic therapy.

Abstract

Background: Snake venom is a complex mixture of biologically active substances. Some peptides and proteins from snake have already demonstrated their therapeutically potential. The venom of Naja haje, an Elapidae member, has been analyzed from this point of view. Understanding the fully biochemical role of its enzymes has determined the scientists to find new separation and identification methods.

Objective: Our goal was to develop an optimal HPLC analytical method for separation and identification of Naja haje snake venom components, known for its neurotoxic activity. In addition, we wanted to find out if crude snake venom could inhibit the development of both Gram-positive and Gram-negative bacterial cultures. Materials and Method: Analysis of venom was performed on a HPLC system using a C16 column with UV detection at 210 nm. The analysis was done using two mobile phases, containing different concentrations of acetonitrile and trifluoroacetic acid aqueous solution at different pH values. An elution gradient was set at a flow of 0.60 mL/min. Bactericidal activity was quantified by measuring inhibition diameter around an aseptically disk filled with crude venom using Staphylococcus aureus and Escherichia coli. Results: An optimal HPLC analytical method has been developed by changing different parameters such as the pH value of mobile phase A or the elution gradient. The best resolution were obtained at a pH value of 7.4, in gradient varying from 5% to 45% in mobile phase B. Microbiological studies of the venom showed that Gram-positive bacteria growth was inhibited by crude venom, while on Gram-negative bacteria growth no effect was observed. Inhibition zone is dose-dependent and fresh crude venom is with 30% more potent than venom freeze and kept at -55°C. Conclusions: A comprehensive catalog of venom composition may serve as a starting point for studying structurefunction correlations of individual toxins for the development of new research tools and drugs of potential clinical use.

Abstract

Tracheoesophageal fistula (TEF) is frequently congenital and requires surgical correction. TEF can also occur secondary to malignant esophageal tumors or benign diseases and these cases are managed by endoscopic means, such as closing the defect with metallic stents. Although esophageal injury can occur secondary to nonsteroidal anti-inflammatory drugs (NSAIDs), TEF secondary to chronic NSAIDs use has not been described in the literature.

We report the case of a male patient with refractory migraine and chronic use of NSAIDs, with a history of esophageal stenosis presenting with acute-onset total dysphagia. Upper gastrointestinal endoscopy and CT-scan revealed TEF located at 25 cm from the incisors. An esophageal stent was placed endoscopically, and 6 weeks a second stent was placed in a stent-in-stent manner to allow removal of both stents. Endoscopic control after the removal of the stents showed the persistence of the fistula, so a third stent was placed as a rescue therapy.

Against medical advice, the patient continued to use OTC painkillers and NSAIDs in large doses. Three months later, he was readmitted with total dysphagia and recent-onset dysphonia. CT scan revealed a new fistula above the already placed stent. A second metallic stent was endoscopically placed through the old stent to close the newly developed fistula. The patient was discharged on the third day with no complications and he remains well at 6 months follow-up.

Due to small cases studies, recurrent TEF remains a therapeutic challenge. Endoscopic therapy is usually an effective solution, but complex cases might require multiple treatment sessions.

Abstract

Introduction

Oxidative stress (OS) seems to be an important mediator of cellular injury, from which sepsis can proceed. Studies have demonstrated the protective effect of controlled hypothermia in sepsis. This study aimed to evaluate its effects on OS parameters in rat hepatic and renal tissue septic after caecal ligation and puncture (CLP).

Material and Methods

Three groups were appointed (10 rats/group): C (control), SN (sepsis normothermic), and SH (sepsis hypothermic). Ten hours from CLP, the liver and kidneys were harvested and total protein concentration, superoxide dismutase (SOD), glutathione peroxidase (GPx) activities, lipid peroxidation level (malondialdehyde (MDA), carbonylated proteins (2,4-dinitrophenylhydrazine (DNPH), and fatty acid profile were analysed.

Results

Sepsis significantly increased SOD and GPx activities in the liver, regardless of the temperature. In renal tissue, GPx activity increased significantly in normothermic conditions and SOD tended to decrease in hypothermic conditions. MDA and DNPH concentrations increase in both tissues after CLP. Hypothermia significantly lowered MDA in the liver but only changed it insignificantly in the kidneys. The DNPH in the liver and kidneys was significantly lower in hypothermic conditions. The unsaturated-to-saturated fatty acids ratio was significantly lower in sepsis, and the fall in temperature raised this ratio.

Conclusion

Experimentally induced sepsis in rats enhances OS in the liver and kidneys. The effect of hypothermia on OS indices is dependent on the type of tissue.