Low dose tranexamic acid effect on post-coronary artery bypass grafting bleeding

Objective: This study investigated the effects of low-dose tranexamic acid on post-coronary artery bypass surgery bleeding. Background: Diffuse microvascular bleeding is still a common problem after cardiac procedures. This study was designed to evaluate the hemostatic effects of low-dose tranexamic acid in on-pump coronary artery bypass graft surgery. Methods: In this prospective randomized placebo-controlled study, 150 patients who were candidates for coronary artery bypass were enrolled and randomly assigned to 1 of 2 groups (tranexamic acid or placebo). Total drainage volume and the need for transfusion as well as surgical complications were recorded and compared in the 2 groups. Results: There was significantly less mediastinal chest tube drainage up to 48 h in the tranexamic acid group (432±210 mL) compared to the placebo group (649±235 mL, p=0.006). In the placebo group, 43 (58) patients were given allogeneic blood during hospital stay compared to 22 (25) in the tranexamic acid group (p<0.001). No significant difference in postoperative complications was seen. Conclusion: The use of low-dose tranexamic acid can significantly reduce blood loss and need for transfusion, with no increase in complications. © The Author(s) 2012 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav

Effect of retransfusion of heparin remaining in the salvaged blood on postoperative blood loss in coronary artery bypass grafting: Comparison with homologous blood transfusion (running title: Postoperative blood loss in CABG)

Background: One of the typical problems of cell savers is the retransfusion of the heparin added to the system. The aim of this study was to determine whether or not heparin, remaining in the prepared sample of retransfusion blood, might be responsible for disturbance in coagulation and increase in blood loss. Methods: Fifty patients undergoing coronary artery bypass grafting surgery (CABG) were randomly divided into two groups: group C (n=25) received cell-saver blood and group H (n=25) received homologous blood. Volumes of the intraoperative autologous and homologous transfusion, activated clotting time (ACT) of the transfused bloods, and ACT and amount of blood loss in the patients were measured intra and postoperatively. Results: There was no statistical difference between the groups in terms of demographics, preoperative characteristics, or operative details. Cell saver was used in 25 cases, and the average volume of blood autotransfused was 504± 158 mL. A significant statistical difference was observed in the mean volumes (460±200 vs. 80±160 mL; P = 0.0001) of perioperative allogeneic blood transfusions between groups H and C. Despite significant further cell-saver blood transfusion (504± 158 cc vs. 338±123 cc; P=0.001) and a significantly longer ACT of cell-saver blood than homologous blood (959±85 sec vs. 478±58 sec; P =0.0001) intraoperatively, there was no significant difference between the two groups in terms of postoperative blood loss (510 ± 270 cc in group H vs. 454 ± 150 cc in group C; P =0.362). Conclusion: Utilization of a cell saver was safe, with no increased risk of bleeding despite heparin added to the system

Impact of garlic tablets on nosocomial infections in hospitalized patients in intensive care units.

BACKGROUND Nosocomial infections are one of the main causes of mortality and morbidity in hospitals, especially in intensive care units (ICUs). OBJECTIVE The aim of this study was to examine the impact of garlic tablets on nosocomial infections in hospitalized patients in intensive care units. METHODS This clinical trial was carried out on 94 patients, admitted to the intensive care units in Kashani and Al-Zahra hospitals from January 21, 2014 to December 20, 2014. Firstly, the patients were randomly selected by simple sampling, then they were assigned into case and control groups. The case group administered one 400 mg garlic tablet daily for 6 days and the control group received placebo. During the study, inflammatory blood factors and infection occurrence in the two groups were compared. The Data were analyzed by SPSS software version 22 through descriptive tests such as independent t-test, Chi-square test, ANOVA and exact Fisher test for the analyses of primary and secondary outcomes. RESULTS During the study period, 78 cases of intravenous catheter tip were sent to laboratory for culture, of which, 37 cases were in the intervention group and 41 in the control group. Culture results of Catheter tips was positive in 5 cases and all five cases were in the control group. Frequency distribution of catheter tip culture was significantly higher in the control group than that of the intervention group (p=0.03). CONCLUSION Based on the results of our study, in people with weakened immune systems and in people with high incidence of opportunistic infections, it is necessary to strengthen their body's immune system stimulants before dealing with these infectious agents, and cause decrease in the diseases insusceptible people. It was suggested that garlic supplementation has shown to be effective in patients admitted to ICU, who are highly susceptible to nosocomial infection, and it can be used for the prevention of septicemia and urinary tract infections. However, further research with larger sample size is needed. TRIAL REGISTRATION The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the Irct ID: IRCT207406156480N6. FUNDING Shahrekord University of Medical Sciences financially supported this research

High porosity and light weight graphene foam heat sink and phase change material container for thermal management

During the last decade, graphene foam emerged as a promising high porosity 3-dimensional (3D) structure for various applications. More specifically, it has attracted significant interest as a solution for thermal management in electronics. In this study, we investigate the possibility to use such porous materials as a heat sink and a container for a phase change material (PCM). Graphene foam (GF) was produced using chemical vapor deposition (CVD) process and attached to a thermal test chip using sintered silver nanoparticles (Ag NPs). The thermal conductivity of the graphene foam reached 1.3 W m(-1)K(-1), while the addition of Ag as a graphene foam silver composite (GF/Ag) enhanced further its effective thermal conductivity by 54%. Comparatively to nickel foam, GF and GF/Ag showed lower junction temperatures thanks to higher effective thermal conductivity and a better contact. A finite element model was developed to simulate the fluid flow through the foam structure model and showed a positive and a non-negligible contributions of the secondary microchannel within the graphene foam. A ratio of 15 times was found between the convective heat flux within the primary and secondary microchannel. Our paper successfully demonstrates the possibility of using such 3D porous material as a PCM container and heat sink and highlight the advantage of using the carbon-based high porosity material to take advantage of its additional secondary porosity

Investigation of Poisoning Prevalence and its Related Factors in Patients Referred to Farsan’s Hospital During 2018-2019, Iran

Background and aims: Poisoning is one of the main medical emergencies that is divided into intentional and unintentional types. According to previous records on poisoning attributed to Farsan’s hospital, Iran, the current study focused on investigating its prevalence, type, and poisonous agent. Methods: In the descriptive-analytical cross-sectional study, the registered data of 557 poisoned patients during 2018-2019 were used by a consensus method. Age, gender, residence, type, and agent of poisoning and hospitalization were employed as explanatory variables. Data were extracted from medical records and entered into the standard checklist. Descriptive statistics such as frequency, percentage, mean, and standard deviation were applied for data analysis. Finally, the chi-square test and independent t test were used to analyze variables in SPSS 22.0. Results: Among a total of 557 poisoning cases, 70% were intentional, 52.1% were related to males, 66% lived in cities, 38.2% were in the age group of 16-30 years, and 58% were associated with drug and opioid use. In addition, 31.4% occurred in spring and about 85% of them were discharged in 2 days. The poisonous agent was different between genders (P ≤ 0.001). Intentional poisoning was more prevalent in youth compared to the elderly and children. Further, poisonous agents demonstrated a significant difference according to the poisoning type, as in intentional poisoning opioids, drugs, and toxins had been used more than the other agents (P ≤ 0.001). Conclusion: In this study, most poisoning cases were intentional, related to males and young individuals, and those residing in cities, and occurred via opioids and drugs. Therefore, it is suggested that more comprehensive studies should be conducted about the cultural and socioeconomic status of vulnerable groups and provide them with appropriate training and attention. Keywords: Poisoning Intentional Poisonous Agent Farsa

Reliability investigation of a carbon nanotube array thermal interface material

As feature density increases within microelectronics, so does the dissipated power density, which puts an increased demand on thermal management. Thermal interface materials (TIMs) are used at the interface between contacting surfaces to reduce the thermal resistance, and is a critical component within many electronics systems. Arrays of carbon nanotubes (CNTs) have gained significant interest for application as TIMs, due to the high thermal conductivity, no internal thermal contact resistances and an excellent conformability. While studies show excellent thermal performance, there has to date been no investigation into the reliability of CNT array TIMs. In this study, CNT array TIMs bonded with polymer to close a Si-Cu interface were subjected to thermal cycling. Thermal interface resistance measurements showed a large degradation of the thermal performance of the interface within the first 100 cycles. More detailed thermal investigation of the interface components showed that the connection between CNTs and catalyst substrate degrades during thermal cycling even in the absence of thermal expansion mismatch, and the nature of this degradation was further analyzed using X-ray photoelectron spectroscopy. This study indicates that the reliability will be an important consideration for further development and commercialization of CNT array TIMs

Thermal characterization and thermal tuning in nanostructured materials

In this dissertation, the experimental investigation of the heat transport in crystalline nanostructured materials is studied. Different methods to reduce their thermal conductivity to create user-specific materials are presented as well. It is shown that by using different methods such as the incorporation of additional elements in the crystalline structure, controlling the deposition and embedding metallic nanoinclusions in the semiconductor matrix, it is possible to reduce the thermal conductivity. Thermal conductivity measurements have been conducted by using pulsed photothermal reflectance (PPR) and 3ω techniques at room temperature. The materials studied in this work include Ti-based hard coatings, multilayer TiN/TiAlN coatings and n-type Bi2Te2.7Se0.3 thermoelectric films. Firstly, the effect of the incorporation of Al on the thermal conductivity of TiAlN coatings prepared by a lateral rotating cathode arc (LARC) technique has been investigated. To study this, a series of TiAlN coatings were deposited on stainless steel substrates and the thermal conductivity of the coatings was measured by the PPR technique. The Microstructure of the coatings was analyzed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). These techniques reveal that TiN coating shows a clear columnar structure with a predominant (111) preferential orientation. With the incorporation of Al, the columnar structure of the coatings is disrupted, the grain size of the coatings is decreased and the dislocation density is increased. A significant decrease in thermal conductivity was found with increasing Al content and a minimum thermal conductivity of about 4.63 W/mK was obtained at the Al/Ti atomic ratio of around 0.72. The decrease in thermal conductivity of the TiAlN coatings is explained in terms of increased phonon scattering due to the decrease in the grain size and increasing dislocation density. The effect of the incorporation of Al and Si on the thermal conductivity of the TiAlSiN nanocomposite coatings prepared by the LARC technique has been studied. A series of TiAlSiN nanocomposite coatings were deposited on stainless steel substrates and the room temperature thermal conductivity of the coatings was measured by the PPR technique. A significant decrease in thermal conductivity was found with increasing Al and Si contents and it was shown that the thermal conductivity of the TiAlSiN nanocomposite coatings is about 1.8 W/mK at a (Al+Si)/Ti atomic ratio of around 1.76. The decrease in thermal conductivity of the TiAlSiN nanocomposite coatings can be attributed to the reduced grain size and the formation of a nanocomposite structure which consists of crystalline nanograins embedded in a disordered, lower thermal conductivity than TiAlN, amorphous SiNx matrix. In order to study the effect of a multilayer structure on the thermal conductivity, a series of multilayer [TiN/TiAlN]n coatings with different bilayer numbers n were deposited on stainless steel substrates by the LARC technique. The PPR technique was employed to measure thermal conductivity of the coatings at room temperature. TEM observation and microstructure analysis of multilayer coatings show a lattice mismatch and misfit dislocations at the interfaces between TiN and TiAlN layers, and a decrease of the grain size with increasing number of layers. Results show that the thermal conductivity of the multilayer coatings reduces with increasing bilayer number n. Phonon scattering is increased at the interfaces and grain boundaries due to the existence of misfit dislocations and to the decreasing grain size, respectively. For the study of the effect of metallic nanoinclusions in thermoelectric (TE) film on the thermal conductivity, textured n-type Bi2Te2.7Se0.3 thin films with Pt nanoinclusions were successfully prepared via pulsed laser deposition. The thermal conductivity of the TE films was measured by the 3ω technique. The TEM observation shows that the Pt nanoinclusions are embedded at the grain boundaries of the semiconductor matrix. By introducing Pt nanoinclusions, the thermal conductivity is reduced due to scattering phonon at the grain boundaries.ELECTRICAL and ELECTRONIC ENGINEERIN

An integrated dynamic model to locate a competitive closed-loop supply chain facility under conditions of uncertainty: A case study of the auto parts industry

With the expansion of competitive markets, supply chain management has become one of the critical issues facing businesses. One of the advantages of sustainable competition for companies is to make supply chain activities more efficient and effective. This paper aims at an integrated closed-loop supply chain (CLSC) problem which is multi-objective, multi-product, multi-period, and multi-level with limited capacities and uncertain conditions of demand and return products. The proposed supply chain network consists of five levels in the forward flow. There are five centers in the backward flow as well. The purpose of this network is to determine the optimal number and location of facilities required in each period and the optimal amount of the transfer flow of products or raw materials through different transportation modes between facilities. In this proposed model, three objective functions are taken into consideration. The first one minimizes all the costs. The second objective function maximizes the quality of products. The third objective function seeks to minimize the sum of deviations from the ideal score of the principal component of each supplier. The data of this research are taken from Pishro Diesel Company. To solve the proposed problem, several methods and algorithms have been used, including unscaled goal programming, boundary objectives, three single-objective meta-heuristic algorithms (PSO, RDA, and TGA), and multi-objective meta-heuristic algorithm (MOGA-II). As the results show, considering products and returned parts in products, a simultaneous practice of forward and reverse supply chains leads to better product quality, less damage to the environment, and lower costs for customers

HTCC-Modified Nanoclay for Tissue Engineering Applications: A Synergistic Cell Growth and Antibacterial Efficiency

This paper deals with the synthesis of a biocompatible chitosan ammonium salt N-(2-hydroxy) propyl-3-trimethylammonium chitosan chloride (HTCC) and using it in montmorillonite ion-exchange process. HTCC-modified montmorillonite (Mt) with different chemical ratios was successfully synthesized, and their characteristics have been verified by XRD and FTIR analyses. Produced samples have been evaluated in terms of antibacterial efficiency and biocompatibility (cell culture test). Antibacterial efficiency of synthesized HTCC/Mt samples has been confirmed against both gram negative bacteria (Escherichia coli) and gram positive bacteria (Staphylococcus aureus). The results disclosed that the antibacterial efficiency of HTCC-modified montmorillonite was unexpectedly even more than HTCC. This excellent synergistic effect has been referred to entrapping bacteria between the intercalated structures of HTCC-modified montmorillonite. Then HTCC on clay layers can seriously attack and damage the entrapped bacteria. An extraordinary biocompatibility, cell attachment, and cell growth even more than tissue culture polystyrene (TCPS) have been recorded in the case of this novel kind of modified clay. Due to existing concerns about serious and chronic infections after implant placement, this natural-based bioactive and antibacterial modified clay can be used in electrospun nanofibers and other polymeric implants with promising mechanical properties for tissue engineering applications