Molecular identification of CTX-M, TEM and SHV β-lactamases in �Klebsiella pneumoniae isolated from respiratory system of patients in the ICU of educational hospitals in Tehran

Background: Extended-spectrum beta-lactamases (ESBL) producing isolates of Klebsiella pneumoniae which have been increased in the hospitals were resulting in limitation of therapeutic options. The aims of this study were to evaluate the antibiotic susceptibility pattern and presence of ESBL genes in clinical isolates of Klebsiella pneumoniae from patients admitted to the intensive care units (ICUs). Materials and Methods: In this descriptive cross-sectional study, a total of 65 Klebsiella pneumoniae strains were isolated from ICUs of educational hospitals in Tehran. Identification was performed using biochemical tests and the antimicrobial susceptibility was performed as recommended by the Clinical and Laboratory Standards Institute (CLSI). Molecular analysis of the ESBL genes was performed by Multiplex PCR (M-PCR). Results: Most of the isolates were resistant to Cotrimoxazole (72.3), Gentamicin (67.7) and Ampicillin (69.2) and the highest susceptibility was seen for Ciprofloxacin (50.8) Tetracycline (49.2), Imipenem (46.3) and Ceftriaxone (43.1). Among the ESBL-producing genes, blaCTX-M (55.3 ) was the most prevalent, followed by blaTEM (41.5 ) and blaSHV (10.7 ). The results showed that 1.5 of the isolates had concurrently blaTEM/ blaSHV and blaSHV/ blaCTX-M genes and 21.6 of isolates the blaTEM/ blaCTX-M genes. Conclusion: These findings reveal the high prevalence of multi drug resistant and ESBL-producing Klebsiella pneumoniae in patients hospitalized in ICUs and emphasize the need for appropriate infection control policies

The occurrence of riddled basins and blowout bifurcations in a parametric nonlinear system

In this paper, a two parameters family $F_{\beta_1,\beta_2}$ of maps of the plane living two different subspaces invariant is studied. We observe that, our model exhibits two chaotic attractors $A_i$, $i=0,1$, lying in these invariant subspaces and identify the parameters at which $A_i$ has a locally riddled basin of attraction or becomes a chaotic saddle. Then, the occurrence of riddled basin in the global sense is investigated in an open region of $\beta_1\beta_2$-plane. We semi-conjugate our system to a random walk model and define a fractal boundary which separates the basins of attraction of the two chaotic attractors, then we describe riddled basin in detail. We show that the model undergos a sequence of bifurcations: "a blowout bifurcation", "a bifurcation to normal repulsion" and "a bifurcation by creating a new chaotic attractor with an intermingled basin". Numerical simulations are presented graphically to confirm the validity of our results.Comment: 26 pages, 15 figure

A multiscale deep learning model for elastic properties of woven composites

Time-consuming and costly computational analysis expresses the need for new methods for generalizing multiscale analysis of composite materials. Combining neural networks and multiscale modeling is favorable for bypassing expensive lower-scale material modeling, and accelerating coupled multi-scale analyses (FE2). In this work, neural networks are used to replace the time-consuming micromechanical finite element analysis of unidirectional composites, representing the local material properties of yarns in woven fabric composites in a multiscale framework. Leveraging the fast multiscale data generation procedure, we presented a second neural networks model to estimate the elastic engineering coefficients of a particular weave architecture based on a broad range of dry resin and fiber properties and yarn fiber volume fraction. As an outcome, this paper provides the user with a generalized, neural network-based approach to tackle the balance of computational efficiency and accuracy in the multiscale analysis of elastic woven composites

Effectiveness of Problem-Focused Coping Strategies on the Burden on Caregivers of Hemodialysis Patients

Background: Studies have shown that family caregivers of hemodialysis patients experience high levels of burden. However, these caregivers are often neglected, and no studies are available on the effectiveness of coping strategies on the burden of care among these caregivers. Objectives: This study aimed to examine the effectiveness of problem-focused coping strategies (communication skills, anger management, and deep breathing) on the burden on caregivers of hemodialysis patients. Patients and Methods: A randomized controlled clinical trial was conducted on 76 family caregivers of hemodialysis patients referred to Shahid Hasheminejad hemodialysis center in Tehran, Iran. The subjects were equally allocated into two groups of 38. Through a coin-tossing method, caregivers of patients who referred on even or odd days of the week were randomly assigned into the intervention group or the control group, respectively. The intervention group received four training sessions on problem-focused coping strategies, but the control group did not receive any intervention. Both groups answered the caregiver’s burnout inventory at the start and six weeks after the last educational session. Descriptive statistics, chi-square, Fisher’s exact test, independent-samples t-test, and Mann-Whitney U test were used to analyze the data. Results: The majority of caregivers (54%) were in the age range of 35 - 55 years, female (68.4%), and married (70%). No significant difference was found between the baseline mean caregivers’ burden scores of the intervention and control groups (88.56 ± 11.74 vs. 84.97 ± 15.13, P = 0.308). However, the mean caregivers’ burden in the intervention group decreased, and the two groups were significantly different at the end of the study (58.77 ± 6.64 vs. 87.84 ± 11.74, P < 0.001). Conclusions: The current study showed the effectiveness of problem-focused coping strategies on reducing the burden on caregivers of hemodialysis patients. Authorities and policymakers in the healthcare system are responsible for developing strategies to integrate educational programs, such as the program implemented in the current study, into the country’s healthcare system

Evaluation of Radicular Dentin Thickness of Danger Zone in Mandibular First Molars

Objective: Better understanding of the furcation anatomy may serve to decrease the risk of root perforation. The purpose of this study was to measure the thickness of root walls in the danger zone in mandibular first molars.Materials and Methods: The roots of 53 extracted human mandibular first molars were sectioned in the horizontal plane 4 mm below the orifice of the mesial and distal root canals.For each cut surface buccal, lingual, mesial, and distal thickness of the root wall wasmeasured. Mean values of the thickness at each location were calculated and compared by ANOVA and t-test.Results: The results showed that the mean thickness in the distal portion of the mesial root was smaller in comparison to all other portions of the roots (P<0.05) and this difference was statistically significant except for the mesial portion of the distal root (P=0.463). The mean thickness of radicular dentin at the distal aspect of mesial roots was 1.2 millimeter.Conclusion: Our study suggests that knowledge of the root dentin thickness in the danger zone is essential for preventing endodontic mishaps leading to failure

Accuracy of early rapid ultrasound in shock (RUSH) examination performed by emergency physician for diagnosis of shock etiology in critically ill patients

Background: Rapid Ultrasound in Shock (RUSH) is a recently reported emergency ultrasound protocol designed to help clinicians better recognize distinctive shock etiologies in a short time. We tried to evaluate the accuracy of early RUSH protocol performed by emergency physicians to predict the shock type in critically ill patients. Materials and Methods: Our prospective study was approved by the ethics committee of trauma research center, Baqiyatallah University of Medical Science, Iran. We enrolled 52 patients with shock state in the emergency department from April 2013 to October 2013. We performed early bed-side sonographic examination for participants based on RUSH protocol. Patients received all needed standard therapeutic and diagnostic interventions without delay and were followed to document their final diagnosis. Agreement (Kappa index) of initial impression provided by RUSH with final diagnosis, and also sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of RUSH for diagnosis of each shock type were calculated. Results: Fifty-two patients were enrolled in our study. Kappa index was 0.7 (P value = 0.000), reflecting acceptable general agreement between initial impression and final diagnosis. For hypovolemic and obstructive shocks, the protocol had sensitivity of 100 but had lower PPV. For shocks with distributive or mixed etiology, RUSH showed PPV of 100 but had low sensitivity. For cardiogenic shocks, all reliability indices were above 90. Conclusion: We highlight the role of RUSH examination in the hands of an emergency physician in making a rapid diagnosis of shock etiology, especially in ruling out obstructive, cardiogenic, and hypovolemic types