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Surveillance of antimicrobial resistance among gram-negative bacteria (GNB) is of critical importance, but data for Peru are not available. To fill this gap, a non-interventional hospital-based surveillance study was conducted in 15 hospitals across Peru from July 2017 to October 2019. Consecutive unique blood culture isolates of key GNB (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter spp.) recovered from hospitalized patients were collected for centralized antimicrobial susceptibility testing, along with linked epidemiological and clinical data. A total of 449 isolates were included in the analysis. Resistance to third-generation cephalosporins (3GCs) was present in 266 (59.2%) GNB isolates. Among E. coli (n = 199), 68.3% showed 3GC resistance (i.e., above the median ratio for low- and middle-income countries in 2020 for this sustainable development goal indicator). Carbapenem resistance was present in 74 (16.5%) GNB isolates, with wide variation among species (0% in E. coli, 11.0% in K. pneumoniae, 37.0% in P. aeruginosa, and 60.8% in Acinetobacter spp. isolates). Co-resistance to carbapenems and colistin was found in seven (1.6%) GNB isolates. Empiric treatment covered the causative GNB in 63.3% of 215 cases. The in-hospital case fatality ratio was 33.3% (92/276). Pseudomonas aeruginosa species and carbapenem resistance were associated with higher risk of in-hospital death. In conclusion, an important proportion of bloodstream infections in Peru are caused by highly resistant GNB and are associated with high in-hospital mortality.
Assuntos
Infecções por Bactérias Gram-Negativas , Sepse , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Escherichia coli , Prevalência , Peru/epidemiologia , Mortalidade Hospitalar , Farmacorresistência Bacteriana , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Carbapenêmicos , Bactérias Gram-Negativas , Klebsiella pneumoniae , Pseudomonas aeruginosa , Sepse/tratamento farmacológico , Testes de Sensibilidade MicrobianaRESUMO
Polyaniline (PANI) composites have gained momentum as supercapacitive materials due to their high energy density and power density. However, some drawbacks in their performance remain, such as the low stability after hundreds of charge-discharge cycles and limitations in the synthesis scalability. Herein, we report for the first time PANI-Graphitic oxidized carbon nitride composites as potential supercapacitor material. The biomimetic polymerization of aniline assisted by hematin, supported by phosphorous and oxygen-modified carbon nitrides (g-POCN and g-OCN, respectively), achieved up to 89% yield. The obtained PAI/g-POCN and PANI/g-OCN show enhanced electrochemical properties, such as conductivity of up to 0.0375 S/cm, specific capacitances (Cs) of up to 294 F/g (at high current densities, 5 A/g) and a stable operation after 500 charge-discharge cycles (at 3 A/g). In contrast, the biomimetic synthesis of Free PANI, assisted by stabilized hematin in cosolvents, exhibited lower performance properties (65%). Due to their structural differences, the electrochemical properties of Free PANI (conductivity of 0.0045 S/cm and Cs of up to 82 F/g at 5 A/g) were lower than those of nanostructured PANI/g-POCN and g-OCN supports, which provide stability and improve the properties of biomimetically synthesized PANI. This work reveals the biomimetic synthesis of PANI, assisted by hematin supported by modified carbon nitrides, as a promising strategy to produce nanostructured supercapacitors with high performance.
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The present investigation involves the coordinative chain transfer polymerization (CCTP) of biobased terpenes in order to obtain sustainable polymers from myrcene (My) and farnesene (Fa), using the ternary Ziegler-Natta catalyst system comprising [NdV3]/[Al(i-Bu)2H]/[Me2SiCl2] and Al(i-Bu)2H, which acts as cocatalyst and chain transfer agent (CTA). The polymers were produced with a yield above 85% according to the monomeric consumption at the end of the reaction, and the kinetic examination revealed that the catalyst system proceeded with a reversible chain transfer mechanism in the presence of 15-30 equiv. of CTA. The resulting polyterpenes showed narrow molecular weight distributions (Mw/Mn = 1.4-2.5) and a high percent of 1,4-cis microstructure in the presence of 1 equiv. of Me2SiCl2, having control of the molecular weight distribution in Ziegler-Natta catalytic systems that maintain a high generation of 1,4-cis microstructure.
RESUMO
The interest in the Coordinative Chain Transfer Polymerization (CCTP) of a family of naturally occurring hydrocarbon monomers, namely terpenes, for the production of high-performance rubbers is increasing year by year. In this work, the synthesis of poly(ß-myrcene) via CCTP is introduced, using neodymium versatate (NdV3), diisobutylaluminum hydrade (DIBAH) as the catalytic system and dimethyldichlorosilane (Me2SiCl2) as the activator. A bimodal distribution in the GPC signal reveals the presence of two populations at low conversions, attributable to dormants (arising from reversible chain transfer reactions) and dead chains (arising from termination and irreversible chain transfer reactions); a unimodal distribution is generated at medium and high conversions, corresponding to the dominant species, the dormant chains. Additionally, a mathematical kinetic model was developed based on the Method of Moments to study a set of selected experiments: ([ß-myrcene]0:[NdV3]0:[DIBAH]0:[Me2SiCl2]0 = 660:1:2:1, 885:1:2:1, and 533:1:2:1). In order to estimate the kinetic rate constant of the systems, a minimization of the sum of squared errors (SSE) between the model predicted values and the experimental measurements was carried out, resulting in an excellent fit. A set of the Arrhenius parameters were estimated for the ratio [ß-myrcene]0:[NdV3]0:[DIBAH]0:[Me2SiCl2]0 = 660:1:2:1 in a temperature range between 50 to 70 °C. While the end-group functionality (EGF) was predominantly preserved as the ratio [ß-myrcene]0:[NdV3]0 was decreased, higher catalytic activity was obtained with a high ratio.
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The overuse of fossil-based resources to produce thermoplastic materials and rubbers is dramatically affecting the environment, reflected in its clearest way as global warming. As a way of reducing this, multiple efforts are being undertaken including the use of more sustainable alternatives, for instance, those of natural origin as the main feedstock alternative, therefore having a lower carbon footprint. Contributing to this goal, the synthesis of bio-based rubbers based on ß-myrcene and trans-ß-farnesene was addressed in this work. Polymyrcene (PM) and polyfarnesene (PF) were synthesized via coordination polymerization using a neodymium-based catalytic system, and their properties were compared to the conventional polybutadiene (PB) and polyisoprene (PI) also obtained via coordination polymerization. Moreover, different average molecular weights were also tested to elucidate the influence over the materials' properties. The crosslinking of the rubbers was carried out via conventional and efficient vulcanization routes, comparing the final properties of the crosslinking network of bio-based PM and PF with the conventional fossil-based PB and PI. Though the mechanical properties of the crosslinked rubbers improved as a function of molecular weight, the chemical structure of PM and PF (with 2 and 3 unsaturated double bonds, respectively) produced a crosslinking network with lower mechanical properties than those obtained by PB and PI (with 1 unsaturated double bond). The current work contributes to the understanding of improvements (in terms of crosslinking parameters) that are required to produce competitive rubber with good sustainability/performance balance.
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STUDY OBJECTIVES: Our aim is to evaluate the presence of REM sleep without atonia (RWA), the objective hallmark of REM sleep Behaviour Disorder (RBD), as prodromal marker of Parkinson's disease (PD), in an adult cohort of 22q11.2 deletion syndrome (22qDS). METHODS: Sleep quality was assessed by means of Pittsburgh quality scale index (PSQI), and RBD symptoms by means of RBD questionnaire-Hong-Kong (RBDQ-HK). Attended domiciliary video-Polysomnography (v-PSG) were performed in 26 adults (18-51 years, 14 females) 22qDS patients. Electromyogram during REM sleep was analyzed by means of SINBAR procedure at 3-second time resolution (miniepochs). RESULTS: An overall poor sleep quality was observed in the cohort and high RBDQ-HK score in 7 of the 26 patients, two additional patients with positive dream enactment reported by close relatives had low score of RBDQ-HK. Nevertheless, SINBAR RWA scores were lower than cut-off threshold for RWA (mean 5.5%, range 0-12.2%). TST and the percentage of light sleep (N1) were increased, with preserved proportions of N2 and N3. Participants reported poor quality of sleep (mean PSQI > 5), with prolonged sleep latency in the v-PSG. No subjects exhibit evident dream enactment episodes during recording sessions. CONCLUSIONS: RWA was absent in the studied cohort of 22qDS adult volunteers according to validated polysomnographic criteria. High RBDQ-HK scores do not correlate with v-PSG results among 22qDS individuals.
Assuntos
Síndrome de DiGeorge , Transtorno do Comportamento do Sono REM , Adulto , Estudos Transversais , Feminino , Humanos , Polissonografia , Transtorno do Comportamento do Sono REM/diagnóstico , Sono REMRESUMO
Correct processing of blood cultures may impact individual patient management, antibiotic stewardship, and scaling up of antimicrobial resistance surveillance. To assess the quality of blood culture processing, we conducted four assessments at 16 public hospitals across different regions of Peru. We assessed the following standardized quality indicators: 1) positivity and contamination rates, 2) compliance with recommended number of bottles/sets and volume of blood sampled, 3) blood culture utilization, and 4) possible barriers for compliance with recommendations. Suboptimal performance was found, with a median contamination rate of 4.2% (range 0-15.1%), with only one third of the participating hospitals meeting the target value of < 3%; and a median positivity rate of 4.9% (range 1-8.1%), with only 6 out of the 15 surveilled hospitals meeting the target of 6-12%. None of the assessed hospitals met both targets. The median frequency of solitary blood cultures was 71.9% and only 8.9% (N = 59) of the surveyed adult bottles met the target blood volume of 8 - 12 mL, whereas 90.5% (N = 602) were underfilled. A high frequency of missed opportunities for ordering blood cultures was found (69.9%, 221/316) among patients with clinical indications for blood culture sampling. This multicenter study demonstrates important shortcomings in the quality of blood culture processing in public hospitals of Peru. It provides a national benchmark of blood culture utilization and quality indicators that can be used to monitor future quality improvement studies and diagnostic stewardship policies.
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Hemocultura/normas , Hospitais Públicos/normas , Sepse/diagnóstico , Manejo de Espécimes/normas , Hemocultura/estatística & dados numéricos , Humanos , Peru , Controle de Qualidade , Sepse/sangue , Manejo de Espécimes/estatística & dados numéricos , Inquéritos e Questionários/normasRESUMO
El presente estudio se realizó con la finalidad de determinar la prevalencia de portadores de Staphylococcus aureus en personal de salud del Hospital Víctor Lazarte Echegaray, durante el mes de agosto del 2003 y determinar su sensibilidad a los antimicrobianos in vitro. Se tomaron muestras de hisopados nasales y faríngeos a personal de cirugía, UCI-UCIN y sala de operaciones las cuales de cultivaron en medio tioglicolato, agar sangre y agar Manitol. Las cepas aisladas se identificaron mediante las pruebas catalasa, coagulasa, coloración gram, acción sobre el manitol y luego se realizaron antibiogramas mediante el método de Kirby y Bauer. Los resultados muestran una prevalencia de 28,6% en personal de salud, en personal médico 38,5%, en técnicos 23,1 % y en enfermeras el 20,8%. En personal del servicio de UCI-UCIN, se halló 46,7%, en cirugía 28,6% y en SOP 15%. Los portadores nasales fueron el 23,8% y faríngeos el 15,9%. De los antimicrobianos utilizados se presentó 100% de sensibilidad a vancomicina, 94,44% a amikacina, 77,78% a oxacilina y ciprofloxacina, el 72,22% a cefalexina, el 55,56% a amoxil/ac. clavulánico y ceclor, el 27,78% a clindamicina y el 16,67% a penicilina.
The present study was carried out with the purpose of determining the prevalencia of payees of Staphylococcus aureus in personal of health of the Hospital Victor to Rope you Echegaray, during the month of August of the 2003 and to determine its sensibility to the antimicrobianos in vitro. They took samples of nasal and pharyngeal hisopados to personal of surgery, UCI-UCIN and room of operations those which of they cultivated between tioglicolato, agar bleeds and agar Manitol. The isolated stumps were identified by means of the tests catalasa, coagulasa, coloration gram, action on the manitol and then they were carried out antibiogramas by means ofthe method of Kirby and Bauer. The results show a prevalencia of 28,6% in personal of health, inpersonnel medical 38,5%, in technicians 23,1% and in nurses 20,8%. In personal of the service of UCI-UCIN, he/she was 46,7%, in surgery 28,6% and in SOP 15%. The nasal payees were 23,8% and pharyngeal 15,9%. Of the used antimicrobianos 100% of sensibility was presented to vancomicina, 94,44% to amikacina, 77,78% to oxacilina and ciprofloxacina, 72,22% to cefalexina, 55,56% to amoxil/ac. clavulánico and ceclor, 27,78% to clindamicina and 16,67% to penicillin.