Resumo Infecções do trato respiratório inferior (ITRIs) são as infecções mais comuns entre pacientes internados em unidade de terapia intensiva (UTI). Pseudomonas aeruginosa é a causa mais comum de ITRIs e está associada ao aumento da mortalidade. Diferentes espécies de Pseudomonas exibem diferentes perfis genéticos e resistência variada as drogas. O presente estudo determina a epidemiologia molecular através do método de fingerprinting de DNA e resistência as drogas de P. aeruginosa isoladas de pacientes com LTRIs internados em UTI. Um total de 79 P. aeruginosa isoladas de pacientes com ITRIs internados em UTI foram caracterizados por Polimorfismo de Comprimento de Fragmentos de Restrição (RFLP), DNA Polimórfico Amplificado ao Acaso (RAPD) e PCR Extrapalindrômico Repetitivo (REP-PCR). A resistência aos antibióticos foram determinadas pelos ensaios de concentrações inibitória mínima (MIC), enquanto os genes MDR, blaTEM, blaOXA, blaVIM, blaCTX-M-15 foram detectados pela reação em cadeia da polimerase (PCR). Das 137 Pseudomonas sp isoladas de pacientes de UTI, 57,7% dos isolados foram relatados como P. aeruginosa. A prevalência geral de P. aeruginosa entre os pacientes incluídos foram de 34,5%. A análise RAPD renderam 45 padrões diferentes com 72 clusters com nível de similaridade de 57% a 100%. A análise RFLP renderam 8 padrões diferentes com 14 clusters com 76% a 100% de similaridade. A análise de PCR do REP produziram 37 padrões diferentes com 65 clusters com nível de similaridade de 56% a 100%. Não houveram correlações entre os diferentes padrões de DNA observados entre os três diferentes métodos. Predominantes dos isolados (46,8%) eram resistentes à amicacina. Dos 79 isolados, 60,8% foram positivos para o gene blaTEM e 39,2% foram positivos para o gene blaOXA. P. aeruginosa foi predominantemente isolado de pacientes com ITRIs internados em UTI. A diferença no nível de similaridade observado entre os três métodos de fingerprinting do DNA indica que há alta variabilidade inter-strain. A alta variabilidade genética e os padrões de resistência indicam que devemos monitorar continuamente a tendência na prevalência e resistência a antibióticos de P. aeruginosa, especialmente em pacientes com ITRIs internados em UTI.

Abstract Lower respiratory tract infections (LRTIs) caused by Pseudomonas aeruginosa are the most common infection among hospitalized patients, associated with increased levels of morbidity, mortality and attributable health care costs. Increased resistant Pseudomonas worldwide has been quite meaningful to patients, especially in intensive care unit (ICUs). Different species of Pseudomonas exhibit different genetic profile and varied drug resistance. The present study determines the molecular epidemiology through DNA fingerprinting method and drug resistance of P. aeruginosa isolated from patients with LTRIs admitted in ICU. A total of 79 P. aeruginosa isolated from patients with LRTIs admitted in ICU were characterized by Restriction Fragment Length Polymorphism (RFLP), Random Amplified Polymorphic DNA (RAPD) and Repetitive Extrapalindromic PCR (REP-PCR). Antibiotic resistance was determined by minimum inhibitory concentration (MIC) assay while MDR genes, viz, blaTEM, blaOXA, blaVIM, blaCTX-M-15 were detected by polymerase chain reaction (PCR). Of the 137 Pseudomonas sp isolated from ICU patients, 57.7% of the isolates were reported to be P. aeruginosa. The overall prevalence of P. aeruginosa among the all included patients was 34.5%. The RAPD analysis yielded 45 different patterns with 72 clusters with 57% to 100% similarity level. The RFLP analysis yielded 8 different patterns with 14 clusters with 76% to 100% similarity level. The REP PCR analysis yielded 37 different patterns with 65 clusters with 56% to 100% similarity level. There was no correlation among the different DNA patterns observed between the three different methods. Predominant of the isolates (46.8%) were resistant to amikacin. Of the 79 isolates, 60.8% were positive for blaTEM gene and 39.2% were positive for blaOXA gene. P. aeruginosa was predominantly isolated from patients with LRTIs admitted in ICU. The difference in the similarity level observed between the three DNA fingerprinting methods indicates that there is high inter-strain variability. The high genetic variability and resistance patterns indicates that we should continuously monitor the trend in the prevalence and antibiotic resistance of P. aeruginosa especially in patients with LRTIs admitted in ICU.

Oxidative stress plays an important role in the development of diabetic cardiomyopathy. In the present study, we determined whether the effect of astragalus polysaccharides (APS) on diabetic cardiomyopathy was associated with its impact on oxidative stress. Streptozotocin (STZ)-induced diabetic mice and heterozygous superoxide dismutase (SOD2+/-) knockout mice were administered APS. The hemodynamics, cardiac ultrastructure, and the apoptosis, necrosis and proliferation of cardiomyocytes were assessed to evaluate the effect of APS on diabetic and oxidative cardiomyopathy. Furthermore, H2O2 formation, oxidative stress/damage, and SOD activity in cardiomyocytes were evaluated to determine the effects of APS on cardiac oxidative stress. APS therapy improved hemodynamics and myocardial ultrastructure with reduced apoptosis/necrosis, and enhanced proliferation in cardiomyocytes from both STZ-induced diabetic mice and heterozygous SOD2+/- knockout mice. In addition, APS therapy reduced H2O2 formation and oxidative stress/damage, and enhanced SOD activity in both groups of mice. Our findings suggest that APS had benefits in diabetic cardiomyopathy, which may be partly associated with its impact on cardiac oxidative stress.

Combining Global Positioning System (GPS) and Short Message Service (SMS), this paper develops a realistic system, called Mobile Navigation and Tracking System (MNTS), to provide navigation and target tracking services. MNTS is an Android based mobile application which integrated many enhanced mechanisms for navigation and target tracking services. MNTS not only provides users with the GPS navigation capability, but also supports Quick Response (QR) code decoding, nearby scenic spot searching, friend positioning and target tracking. In target tracking, MNTS utilizing SMS mainly adopts two proposed novel approaches: location prediction and dynamic threshold to reduce the number of short message transmissions while maintaining location accuracy within an acceptable range. Location prediction utilizes the current target’s location, moving speed, bearing to predict its next location. When the distance between the predicted location and the actual location exceeds a threshold, the target sends a short message to the tracker to update the actual location. Based on the movement speed of the target, the threshold is dynamically adjusted to balance the location accuracy and the number of short messages. Furthermore, as MNTS is free and open-source software, service providers or developers can easily extend their own services based on this system.

The relationship between the aspect ratio and physical fields in aluminium reduction cells wase studied numerically. The aspect ratio was firstly defined and 7 kinds of 320 kA cells with different aspect ratios were put forward. By using numerical simulation, the relationship between the aspect ratio and the electric-magnetic flow fields, magnetohydrodynamic stabilities, and thermal stability was discussed. It is concluded that the electric-magnetic flow field distributions are greatly affected by the aspect ratio. From the perspective of magnetohydrodynamics stability, the larger the aspect ratio is, the more stable the cell will be. A larger aspect ratio is more beneficial for the thermal stability under the same current density.