Significant Increase In Resistance Research Articles

The effect of La2O3 and CeO2 modifiers on properties of Ni–Al catalysts for LNG prereforming

Ni/La–Al2O3 and Ni/Ce–Al2O3 catalysts with a small amount of promoters intended for prereforming of LNG were characterized by XRF, N2 adsorption-desorption, XRD, H2 chemisorption, HRTEM and XPS. The catalytic activity was evaluated in methane steam reforming both in the kinetic and diffusion regime, at temperatures characteristic of pre-reforming. Carbonaceous deposit was analysed by TPO-MS method. The nature and location of the coke were studied by HRTEM.La or Ce addition into Ni–Al system causes the increase of the active surface area of Ni by enhancing its dispersion. Studies at kinetic regime have shown that the promoted catalysts have almost twice the activity than reference Ni–Al catalyst. This effect was not confirmed by measurements in the diffusion regime on whole catalyst tablets. Almost identical textural properties of catalysts and diffusive limitations related to them but not the catalytic properties of the material itself appeared to be crucial factors. The presence of La (but not Ce) causes a significant increase in resistance to coking.

Comparison of Field and Laboratory Result of Fiber Reinforced Shotcrete Application

Synthetic fibers, which have become one of the main components of shotcrete, have been studied by many researchers in the laboratory environment. Unfortunately, the results obtained as a result of these researches are not suitable for underground chimneys due to the differences in ambient conditions and application differences. In this study, it is aimed to compare the results of the experiment samples prepared and kept in the laboratory with the mechanical properties of the shotcrete applied in underground conditions. For this purpose, keeping the slump and cement proportions constant, 35 cubic samples were prepared using 2 and 6 kg synthetic fiber for 1 m3 in the laboratory, and 30 cylinder samples and 6 plate samples were prepared for underground. While mechanical experiments were carried out on prepared cube and cylinder samples, the EFNARC plate test and freeze-thaw test were carried out on plate samples. It was observed that the set accelerator made a significant increase in resistance at the end of the 28 days and that the resistance of the samples prepared with polyester fibers in the laboratory environment were very high. As a result of the EFNARC panel tests performed, it was determined that the energy absorption of synthetic fibers increased with fiber amount. Thanks to this study, the energy absorption of the synthetic fiber used has been measured, and the reliability and practicality of the experiments carried out in the laboratory have been increased by evaluating the field conditions and laboratory conditions.

Antimicrobial resistance of Salmonella from poultry meat in Brazil: results of a nationwide survey

Abstract The use of antimicrobials in food-producing animals can lead to increased bacterial resistance. Important information to address this problem can be provided by monitoring antimicrobial resistance (AMR) in foodborne pathogens. As part of preliminary activities for the implementation of AMR surveillance in Brazil, a nationwide survey on AMR in Salmonella enterica isolates from poultry meat was conducted. The survey evaluated 146 Salmonella isolates from poultry meat in 2014, and 163 isolates obtained in 2017. Minimal inhibitory concentrations of 13 antimicrobials were determined by broth microdilution, and isolates were assigned to serotypes by automated ribotyping. High resistance rates were found in 2014 and 2017, in particular to nalidixic acid (84/146, 57.5% and 141/163, 86.5%, respectively), ampicillin (82/146, 56.2% and 125/163, 76.7%), cefotaxime (76/146, 52.1% and 124/163, 76.1%), ceftazidime (73/146, 50.0% and 124/163, 76.1%), ciprofloxacin (83/146, 56.9% and 145/163, 89.0%) and tetracycline (88/146, 60.3% and 135/163, 82.8%). There was a significant increase in resistance to these antibiotics in the second survey period. Salmonella ser. Heidelberg and Salmonella ser. Minnesota were the main serotypes expressing resistance to these antimicrobials. Multidrug resistance was found in 50.7% (74/146) of the isolates from 2014, and in 77.3% (126/163) of isolates from 2017 (P < 0.05). None of the isolates was resistant to azithromycin or meropenem. These findings indicate high and increasing rates of resistance among Salmonella from poultry meat in Brazil, mainly associated with Salmonella ser. Heidelberg and Salmonella ser. Minnesota, stressing the importance of continuous monitoring of AMR in the poultry chain.

New technological methods of protecting the sur-faces of the parts of transport and lifting machines against fretting corrosion

Damage to the surfaces of parts of transport and lifting machines from fretting wear is accompanied by the emergence of stress concentrators, changes in the mechanical properties of structural elements, weakening of tension and other phenomena, which leads to the destruction of individual structural elements and can cause serious accidents. Thus, the study of the problems of fretting wear, the study of the causes of its occurrence and the development of methods to increase fretting resistance is an urgent task that requires timely solution. Goal. The purpose of the work is to increase the reliability and durability of parts of transport and lifting machines by increasing the fretting resistance of joints by forming special coatings on the contact surfaces of the connecting parts. Methodology. Both analytical methods of research and experimental check of efficiency of the offered methods of increasing resistance against fretting wear of parts’ surfaces were used. Results. A study of the influence of various factors on the intensity and features of fretting processes on the contact surfaces of various parts of transport and lifting machines, substantiated the use of methods of electric spark alloying, epilation, metal plating of surfaces subjected to fretting wear. Originality. A new method of manufacturing a fixed joint type "Shaft - hub" of steel parts is offered, which provides the increased fatigue strength of the shafts in fixed joints and recommendations are developed for the materials used and processing modes. A new method of protecting the parts of the elastic coupling from fretting corrosion is proposed, in which a chemical and physical effect is performed on the surface layer of the parts in contact with friction pairs. A new method is offered for protecting flexible elements of elastic couplings from fretting corrosion and increasing their durability in more severe operating conditions, by changing the quality parameters of their surface layers by applying corrosion-resistant lubricants. Practical value. The use of the proposed technological methods provides a significant increase in resistance to fretting wear of the parts’ surfaces, which is confirmed by the results of the bench tests.

Emerging trends in the antimicrobial resistance among uropathogens

Emerging trends in the antimicrobial resistance among uropathogens - IJMR- Print ISSN No: - 2394-546X Online ISSN No:- 2394-5478 Article DOI No:- 10.18231/2394-5478.2018.0009, Indian Journal of Microbiology Research-Indian J Microbiol Res

Development of magnetosomes-based biosensor for the detection of Listeria monocytogenes from food sample.

Listeriosis through contaminated food is one of the leading causes of premature deaths in pregnant women and new born babies. Here, the authors have developed a magnetosomes-based biosensor for the rapid, sensitive, specific and cost-effective detection of Listeria monocytogenes from food sample. Magnetosomes were extracted from Magnetospirillum sp. RJS1 and then directly bound to anti-Listeriolysin antibody (0.25-1 µg/ml), confirmed in spectroscopy. Listeriolysin (LLO) protein (0.01-7 µg/ml) was optimised in enzyme-linked immunosorbent assay. Magnetosomes was conjugated with LLO antibody (0.25 µg/ml) in optimum concentration to detect LLO protein (0.01 µg/ml). Magnetosomes-LLO antibody complex was 25% cost effective. The magnetosomes-LLO antibody complex was directly stabilised on screen printed electrode using external magnet. The significant increase in resistance (RCT value) on the electrode surface with increase in concentration of LLO protein was confirmed in impedance spectroscopy. The L. monocytogenes contaminated milk and water sample were processed and extracted LLO protein was detected in the biosensor. The specificity of the biosensor was confirmed in cross-reactivity assay with other food pathogens. The detection limit of 101 Cfu/ml in both water and milk sample manifests the sensitive nature of the biosensor. The capture efficiency and field emission scanning electron microscopy confirmed positive interaction of Listeria cells with magnetosomes-antibody complex.

Further SAR on the (Phenylsulfonyl)piperazine Scaffold as Inhibitors of the Aedes aegypti Kir1 (AeKir) Channel and Larvicides.

Zika virus (ZIKV), dengue fever (DENV) and chikungunya (CHIKV) are arboviruses that are spread to humans from the bite of an infected adult female Aedes aegypti mosquito. As there are no effective vaccines or therapeutics for these diseases, the primary strategy for controlling the spread of these viruses is to prevent the mosquito from biting humans through the use of insecticides. Unfortunately, the commonly used classes of insecticides have seen a significant increase in resistance, thus complicating control efforts. Inhibiting the renal inward rectifier potassium (Kir) channel of the mosquito vector Aedes aegypti has been shown to be a promising target for the development of novel mosquitocides. We have shown that Kir1 channels play key roles in mosquito diuresis, hemolymph potassium homeostasis, flight, and reproduction. Previous work from our laboratories identified a novel (phenylsulfonyl)piperazine scaffold as potent AeKir channel inhibitors with activity against both adult and larval mosquitoes. Herein, we report further SAR work around this scaffold and have identified additional compounds with improved in vitro potency and mosquito larvae toxicity.

Retrospective Analysis on Antimicrobial Resistance Trends and Prevalence of β-lactamases in Escherichia coli and ESKAPE Pathogens Isolated from Arabian Patients during 2000-2020.

The production of diverse and extended spectrum β-lactamases among Escherichia coli and ESKAPE pathogens is a growing threat to clinicians and public health. We aim to provide a comprehensive analysis of evolving trends of antimicrobial resistance and β-lactamases among E. coli and ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acine to bacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) in the Arabian region. A systematic review was conducted in Medline PubMed on papers published between January 2000 and February 2020 on countries in the Arab region showing different antibiotic resistance among E. coli and ESKAPE pathogens. A total of n = 119,144 clinical isolates were evaluated for antimicrobial resistance in 19 Arab countries. Among these clinical isolates, 74,039 belonged to E. coli and ESKAPE pathogen. Distribution of antibiotic resistance among E. coli and ESKAPE pathogens indicated that E. coli (n = 32,038) was the predominant pathogen followed by K. pneumoniae (n = 17,128), P. aeruginosa (n = 11,074), methicillin-resistant S. aureus (MRSA, n = 4370), A. baumannii (n = 3485) and Enterobacter spp. (n = 1574). There were no reports demonstrating Enterococcus faecium producing β-lactamase. Analyses revealed 19 out of 22 countries reported occurrence of ESBL (Extended-Spectrum β-Lactamase) producing E. coli and ESKAPE pathogens. The present study showed significantly increased resistance rates to various antimicrobial agents over the last 20 years; for instance, cephalosporin resistance increased from 37 to 89.5%, fluoroquinolones from 46.8 to 70.3%, aminoglycosides from 40.2 to 64.4%, mono-bactams from 30.6 to 73.6% and carbapenems from 30.5 to 64.4%. An average of 36.9% of the total isolates were reported to have ESBL phenotype during 2000 to 2020. Molecular analyses showed that among ESBLs and Class A and Class D β-lactamases, blaCTX-M and blaOXA have higher prevalence rates of 57% and 52.7%, respectively. Among Class B β-lactamases, few incidences of blaVIM 27.7% and blaNDM 26.3% were encountered in the Arab region. Conclusion: This review highlights a significant increase in resistance to various classes of antibiotics, including cephalosporins, β-lactam and β-lactamase inhibitor combinations, carbapenems, aminoglycosides and quinolones among E. coli and ESKAPE pathogens in the Arab region.

Changes in antimicrobial resistance patterns of ocular surface bacteria isolated from horses in the UK: An eight‐year surveillance study (2012‐2019)

To identify temporal changes in antimicrobial resistance of ocular surface bacteria isolated from clinically symptomatic equine eyes in the South West of the UK. Retrospective. Clinical and laboratory records of horses treated for suspected bacterial ocular surface disease (ulcerative and non-ulcerative) at a single facility between January 2011 and December 2019 were reviewed. Cases were included if they underwent ocular surface sampling, aerobic bacterial culture, and antimicrobial susceptibility testing. Cases were split into two time periods based on when sampling occurred: "early" (2012-2015) and "late" (2016-2019) to enable identification of temporal trends in resistance to chloramphenicol, gentamicin, fusidic acid, neomycin, cloxacillin, ofloxacin, and polymyxin B. A total of 125 samples from 110 horses were included in analyses. Culture-positive isolates were identified in 76/110 (60.8%) samples. Principal isolates included Staphylococci spp. (n=45; 64.3%), Streptococcispp. (n=14; 20%), and Enterobacterspp. (n=11; 15.7%). There was a significant increase in resistance to chloramphenicol over time (P=.007) and a decrease in resistance to ofloxacin that approached significance (P=.059). Chloramphenicol (100%) and gentamicin (85.7%) had the highest overall in-vitro efficacy during the early and late periods, respectively. There was no significant difference in the type of bacteria isolated across the two time periods. These results suggest a potential increase in resistance to chloramphenicol among bacteria isolated from the ocular surface of horses in the South West UK, reinforcing the value of surveillance to guide the empirical use of antimicrobials.

Chemical Composition and Effectiveness of Ocimum basilicum L. Extracts on the Adhesion of Candida albicans and C. dubliniensis on Acrylic Surfaces of Removable Orthodontic Appliances

The outbreak of diseases caused by Candida species is growing. These opportunistic pathogens can produce biofilm on non-biological surfaces, such as removable orthodontic appliances. Over the past two decades, there has been a significant increase in resistance to several types of antifungal drugs. Recently, there is a growing interest in using herbal plants and their extracts as an alternative to antifungal drugs. A common plant is basil, which belongs to Lamiaceae family. This study aimed to determine the effect of basil extracts on the adhesion of C. albicans and C. dubliniensis to acrylic surfaces of removable orthodontic appliances. Basil dried leaves were macerated in ethanol to extract its constituent, and then the extract was dissolved in water and fractioned by other solvents, including n-hexane and ethyl acetate, successively. The minimum inhibitory concentrations (MIC) of the extracts against standard species of Candida were determined by the broth microdilution method based on clinical and laboratory standard institute (CLSI) protocol. Afterward, adherence and biofilm formation tests were done on acrylic specimens in the vicinity of proper concentration of fractions with the help of the Crystal Violet and spectrophotometry method. MIC for ethyl acetate fraction, n-hexane fraction, ethanol crude extract, and the aqueous fraction was 1024, 2048, ≥2048, >2048 µg/ml, respectively. Inhibition of adherence and biofilm formation for Candida albicans and Candida dubliniensis in the vicinity of ethyl acetate fraction was 73% and 78%, respectively. In the vicinity of n-hexane fraction was 65% and 78%, respectively. Two fractions could inhibit the growth, adherence, and biofilm formation of two Candida species.

Emergence of macrolide-resistant Streptococcus pyogenes emm12 in southern Taiwan from 2000 to 2019

Group A Streptococcus (GAS) is an important pathogen causing morbidity and mortality worldwide. Surveillance of resistance and emm type has important implication to provide helpful information on the changing GAS epidemiology and empirical treatment. To study the emergence of resistant GAS in children with upper respiratory tract infection (URTI), a retrospective study was conducted from 2000 to 2019 in southern Taiwan. Microbiological studies, including antibiotic susceptibility, were performed. GAS emm types and sequences were determined by molecular methods. The population was divided into two separate decades to analyze potential changes over time. The 1st decade was 2000-2009; the 2nd decade was 2010-2019. Multivariate analyses were performed to identify independent risk factors associated with macrolide resistance between these periods. A total of 320 GAS from 339 children were enrolled. Most of the children (75%) were under 9 years of age. The most common diagnosis was scarlet fever (225, 66.4%), and the frequency increased from 54.8% in the 1st to 77.9% in the 2nd decade (p<0.0001). There was a significant increase in resistance to erythromycin and azithromycin from 18.1%, 19.3% in the 1st to 58.4%, 61.0% in the 2nd decade (p<0.0001). This was associated with clonal expansion of the GAS emm12-ST36 which carrying erm(B) and tet(M) from 3.0% in the 1st to 53.2% in the 2nd decade (p<0.0001). Significant emergence of macrolide-resistant GAS emm12-ST36 in children supports the need for continuing surveillance and investigation for the clonal virulence.

Resistance to Antibiotics of Uropathogen Bacteria Isolated From Urine and Blood in Pediatric Cancer Patients: A Single Center, 12-year Study.

Resistant pathogens have become a major healthcare problem in children with cancer, causing different kinds of infections such as the bloodstream ones, most common, and most frequently described and the urinary tract ones, of which less data are available. We analyzed and compared the proportions, and the trends of resistance in pathogens isolated from blood and urines in children with cancer followed in IRCCS Istituto Giannina Gaslini, Genova, Italy, from January 2007 to December 2018. Overall, 345 strains detected in urines and 282 in bloodstream infections were analyzed. Enterobacteriales were the most frequently isolated pathogens. During the study period in urines, there was a significant increase of resistance to ceftazidime, ciprofloxacin, piperacillin/tazobactam, and trimethoprim-sulfamethoxazole, but pathogens from blood were significantly more frequently resistant to amikacin, piperacillin/tazobactam, and combination therapy piperacillin/tazobactam+amikacin, even if with a decreasing trend during the study period. These data confirm the importance of surveillance of isolated microorganism and antibiotic resistance in cancer children.

Dual-crystallization waterproofing technology for topical treatment of concrete

Concrete structures and pavements are subjected to various durability problems associated with moisture penetration through the pores and the capillary networks. Published data on waterproofing has provided conflicting and inaccurate information on crystalline-based technologies. Chem-Crete Pavix DCE is a patented, dual-crystalline waterproofing technology with performance characteristics which are materially distinct from other crystalline-based technologies. It combines hygroscopic crystallization, hydrophilic crystallization and hydrophobic characteristics. This publication presents the results of experimental research work on the significant characteristics of the dual-crystallization waterproofing technology as a treatment for existing or fully cured concrete. A program of laboratory testing has been completed in compliance with applicable ASTM and AASHTO standards using common concrete design mixes, in addition to cored specimens obtained from existing concrete pavements. The investigated experimental parameters included pore size, density, permeability, water absorption, resistance to cycles of freezing and thawing, chloride ion penetration, and mechanical properties of the surface, including pull-off strength, abrasion resistance and the coefficient of friction.Treated concrete has been found to have higher density, less voids, less surface area, and lower permeability than untreated specimens. These characteristics yielded significant reduction in water absorption, significant increase in resistance to damage from freezing and thawing and to biological attack, and significant reduction in chloride ion penetration, without negative impacts on mechanical properties.

Printed Strain Sensor with High Sensitivity and Wide Working Range Using a Novel Brittle-Stretchable Conductive Network.

There are few reports on resistive strain sensors that exhibit both high sensitivity and a wide working range under stretching. We have newly developed a high-performance strain sensor based on a brittle-stretchable conductive network that consists of both brittle and stretchable conductive layers and is fabricated on a stretchable substrate using the screen-printing method. Adding strain usually generates structural cracks in brittle conductive layers leading to a significant increase in resistance, while a stretchable conductive layer bridges these cracks to maintain the conductive pathways under high-strain conditions. This novel conductive network endows superior electrical-mechanical performance to the strain sensors, which possess high sensitivity (gauge factor > 870) over the entire working range (∼100%). Additionally, the developed sensors showed unique anisotropic bend-sensing characteristics, which could be used to detect the bending directions. This high degree of comprehensive performance results in a strain sensor with the capability for full-range human motion detection and robotic motion sensing.

Genome‐wide association mapping of Fusarium langsethiae infection and mycotoxin accumulation in oat (Avena sativa L.)

Fusarium langsethiae is a symptomless pathogen of oat panicles that produces T-2 and HT-2 mycotoxins, two of the most potent trichothecenes produced by Fusarium fungi in cereals. In the last few years, the levels of these mycotoxin in oat grain has increased and the European commission have already recommended a maximum level for of 1000 μg kg-1 for unprocessed oat for human consumption. The optimal and most sustainable way of combating infection and mycotoxin contamination is by releasing resistant oat varieties. Here the objective was to determine if we could identify any genomic loci associated with either the accumulation of F. langsethiae DNA or mycotoxins in the grain. In each of two years, field trials were conducted wherein 190 spring oat varieties were inoculated with a mixture of three isolate of the pathogen. Mycotoxins were quantified using liquid chromatography-tandem mass spectrometry. Varieties were genotyped using 16,863 genotyping by sequencing markers. Genome-wide association studies associated 5 SNPs in the linkage group Mr06 with T-2 + HT-2 mycotoxin accumulation. Markers were highly correlated, and a single QTL was identified. The marker avgbs_6K_95238.1 mapped within genes showing similarity to lipase, lipase-like or lipase precursor mRNA sequences and zinc-finger proteins. These regions have previously been shown to confer a significant increase in resistance to Fusarium species.

Shear Bond Strength of Metal Brackets Recycling with Aluminum Oxide

Objective: to evaluate the shear bond strength of metal brackets subjected to recycling with aluminum oxide. Methods: 20 premolars were used, divided into two groups (n = 10) according to the brackets used (G1: Morelli® Light and G2: Morelli® Max). The teeth were autoclaved, included in ¾-inch PVC tubes, perpendicular to the ground. The brackets were fixed on the dental crowns with the TransbondTM XT kit (3M Unitek). The specimens were subjected to thermal cycling. The shear test was performed on the Instron® 5582 testing machine, at a speed of 0.5mm / min. The brackets were recycling with aluminum oxide 24 hours after the test. A new shear was performed, similar to the first. The buccal faces of the teeth were qualified through the IRA in both tests. The data were submitted to statistical analysis using the Kruskal-Wallis, ANOVA and Tukey tests (p &lt;0.05). Results: in the first shear, the bond strength values of Morelli® Max brackets (35,00MPa) were statistically higher than those of Morelli®Light (23,86MPa). In the second, the resistances were statistically similar (Morelli®Max: 37,19 MPa and Morelli®Light: 45,18 MPa). The Morelli® Light bracket was influenced by the recycling of aluminum oxide, with a significant increase in resistance from the first to the second test. There was no significance for the values of the IRA scores in both trials. Conclusion: recycling with aluminum oxide influenced the shear bond strength of the Morelli®Light bracket, causing an increase in adhesion strength; the Morelli® Max bracket was superior to Morelli® Light before recycling; after recycling, the brackets had similar behaviors.

Using the ERFI Function in the Problem of the Shape Optimization of the Compressed Rod

The shape of the optimal rod determined in the work meets the condition of mass conservation in relation to the reference rod. At the same time, this rod shows a significant increase in resistance to axial force. In the examples presented, this increase was &lt;i&gt;80&lt;/i&gt;% and &lt;i&gt;117&lt;/i&gt;%, respectively, for rods with slenderness of 125 and 175. A practical benefit from the use of compression rods of the proposed shapes is clearly visible. The example presented in this publication shows how great the utility in the structural mechanics can be, resulting from the applications of complex analysis (complex numbers). This approach to many problems can find its solutions, while they are lacking in the real numbers domains. What is more, although these are operations on complex numbers, these solutions have often their real representations, as the numerical example shows. There are too few applications of complex numbers in the technique and science, therefore it is obvious that the use of complex analysis should have an increasing range. One of the first people to use complex numbers was Girolamo Cardano. Cardano, using complex numbers, was solving cubic equations, unsolvable to his times – as the famous Franciscan and professor of mathematics Luca Pacioli put it in his paper &lt;i&gt;Summa de arithmetica, geometria, proportioni et proportionalita&lt;/i&gt; (1494). It is worth mentioning that history has given Cardano priority in the use of complex numbers, but most probably they were discovered by another professor of mathematics – Scipione del Ferro (cf. [1]). We can see, that already then, they were definitely important (complex numbers).

Organ blood flow in response to infusion of arginine vasopressin in premature fetal sheep.

Arginine vasopressin (AVP) infusion has been shown to be a useful strategy for the management of systemic perfusion failure in premature infants. Our objective was to determine the characteristics of the blood flow redistribution induced by AVP infusion in premature fetal sheep. Nine sheep fetuses at 99 to 113days of gestation were continuously infused with AVP. Measurement of blood flow to individual fetal organs was performed using a colored microsphere technique, with measurements performed at 30min before and 90min after the initiation of AVP infusions. The AVP infusion significantly increased blood flow to the medulla oblongata (P < 0.05), and significantly decreased flow to the adrenal glands (from 492.0 ± 239.6 to 364.9 ± 143.3mL/min/100g, P < 0.05) and heart (from 592.6 ± 184.5 to 435.6 ± 137.4mL/min/100g, P < 0.05). The infusion significantly increased the vascular resistance in adrenal glands, kidneys, ileum, colon, heart, and cerebellum. In the brain, except for the cerebellum, no significant increase in resistance was identified. There was no significant response to AVP infusion in cerebral blood flow in mid-gestation fetal sheep. Our observations suggest that, under AVP stimulation, the blood flow to the adrenal glands and myocardium might be decreased due to an increase in vascular resistance.

Resistance Reduction of Conductive Patterns Printed on Textile by Curing Shrinkage of Passivation Layers.

Directly printing conductive ink on textiles is simple and compatible with the conventional electronics manufacturing process. However, the conductive patterns thus formed often show high initial resistance and significant resistance increase due to tensile deformation. Achieving conductive patterns with low initial resistance and reduced deformation-induced resistance increase is a significant challenge in the field of electronic textiles (e-textiles). In this study, the passivation layers printed on conductive patterns, which are necessary for practical use, were examined as a possible solution. Specifically, the reduction of the initial resistance and deformation-induced resistance increase, caused by the curing shrinkage of passivation layers, were theoretically and experimentally investigated. In the theoretical analysis, to clarify the mechanism of the reduction of deformation-induced resistance increase, crack propagation in conductive patterns was analyzed. In the experiments, conductive patterns with and without shrinking passivation layers (polydimethylsiloxane) cured at temperatures of 20–120 °C were prepared, and the initial resistances and resistance increases due to cyclic tensile and washing in each case were compared. As a result, the initial resistance was reduced further by the formation of shrinking passivation layers cured at higher temperatures, and reduced to 0.45 times when the curing temperature was 120 °C. The cyclic tensile and washing tests confirmed a 0.48 and a 0.011 times reduction of resistance change rate after the 100th elongation cycle (10% in elongation rate) and the 10th washing cycle, respectively, by comparing the samples with and without shrinking passivation layers cured at 120 °C.

Changing epidemiology and resistance patterns of pathogens causing neonatal bacteremia.

To conduct a survey of the local prevalent bacteria and antibiotic resistance in a referral tertiary neonatal intensive care unit (NICU), in order to assess the efficacy of local antibiotic policies. We reviewed all positive blood and cerebrospinal fluid cultures obtained between January 2007 and December 2017 in the NICU of Schneider Children's Medical Center of Israel. Early and late-onset bacteremia were defined as episodes occurring within or after the first 3 calendar days of life respectively. Empiric treatment included ampicillin and gentamicin or piperacillin-tazobactam and amikacin for early or late-onset bacteremia respectively. The prevalence and antibiotic resistance of the bacteria were described and compared over time. Eight hundred and twenty nine of 15,947 (5.2%) newborns had at least one episode of bacteremia; 81 had multiple episodes. The most common bacteria were Escherichia coli (32.35%) and group B Streptococcus (19.11%) or coagulase negative Staphylococcus (CoNS) (60.5%) and Klebsiella sp. (12.4%) in early or late-onset bacteremia respectively. Overall, all Gram-positive bacteria were susceptible to vancomycin and most non-CoNS to ampicillin. Nosocomial vs. vertical bacteremia had increased resistance to ampicillin and cephalosporins. Resistance of nosocomial bacteria to piperacillin-tazobactam was 22.4%, to amikacin 3.3%, and to meropenem 1.8%. Changes over time: Gram-negative bacteria had a significant increase in resistance to cotrimoxazole and piperacillin. The resistance to gentamicin doubled. Our empiric antibiotic regimen covers the most frequent isolates. Amikacin may replace gentamicin for selected sick patients in early-onset bacteremia. Piperacillin-tazobactam should be combined with amikacin until susceptibility is available.