16 research outputs found
A Miniature RFID Antenna at UHF Band using Meander-Line Technique
This paper displays a new design of a small antenna proposed for radio-frequency identification (RFID) applications in the UHF band (ultra-high frequency). Our antenna is constituted of two rectangular patches linked together with a meander line. Using this technique reduction in antenna size of equal to 62% with respect to the conventional antenna was achieved. The antenna has a simple structure and small antenna size of 60 x 74mm2 or 0.184 λ0 x 0.226 λ0. It has been fabricated on a low-cost FR4 substrate and measured to validate the simulation performances.The measured bandwidth is around 54.4 MHz (889.3 - 943.7 MHz) with reflection coefficient less than 10 dB, which covers all of the American RFID band (902 - 928 MHz), Chinese RFID band (920.5 - 924.5 MHz), Korea Republic and Japan RFID band ( 917 - 923.5 MHz).The design and simulations have been effected by electromagnetic simulators HFSS and CST microwave studio. A good accord is getting between the simulated and measured results. This antenna is intended for the reader of RFID applications
Hypoxia enhances ILC3 responses through HIF-1α-dependent mechanism
Group 3 innate lymphoid cells (ILC3) have a prominent role in the maintenance of intestine mucosa homeostasis. The hypoxia-inducible factor (HIF) is an important modulator of immune cell activation and a key mechanism for cellular adaptation to oxygen deprivation. However, its role on ILC3 is not well known. In this study, we investigated how a hypoxic environment modulates ILC3 response and the subsequent participation of HIF-1 signaling in this process. We found increased proliferation and activation of intestinal ILC3 at low oxygen levels, a response that was phenocopied when HIF-1α was chemically stabilized and was reversed when HIF-1 was blocked. The increased activation of ILC3 relied on a HIF-1α-dependent transcriptional program, but not on mTOR-signaling or a switch to glycolysis. HIF-1α deficiency in RORyt compartment resulted in impaired IL-17 and IL-22 production by ILC3 in vivo, which reflected in a lower expression of their target genes in the intestinal epithelium and an increased susceptibility to Clostridiodes difficile infection. Taken together, our results show that HIF-1α activation in intestinal ILC3 is relevant for their functions in steady state and infectious conditions
Reviewing the <i>Clostridioides difficile</i> Mouse Model: Insights into Infection Mechanisms
Clostridioides difficile is an anaerobic, spore-forming bacterium associated with intestinal infection, manifesting a broad spectrum of gastrointestinal symptoms, ranging from mild diarrhea to severe colitis. A primary risk factor for the development of C. difficile infection (CDI) is antibiotic exposure. Elderly and immunocompromised individuals are particularly vulnerable to CDI. A pivotal aspect for comprehending the complexities of this infection relies on the utilization of experimental models that mimic human CDI transmission, pathogenesis, and progression. These models offer invaluable insights into hostâpathogen interactions and disease dynamics, and serve as essential tools for testing potential therapeutic approaches. In this review, we examine the animal model for CDI and delineate the stages of infection, with a specific focus on mice. Our objective is to offer an updated description of experimental models employed in the study of CDI, emphasizing both their strengths and limitations
Substrates for the tree of seed germination of carmar (Carthamus tinctorius L.)
The objective of this work was to evaluate the different substrates in the germination potential of safflower seeds. A completely randomized design was used, with five substrates: paper roll, between paper, on paper; Between sand and sand. Seeds of two safflower cultivars were used, with four replicates of 50 seeds each. It was evaluated: percentage of germination (GER); First germination count (GPC); Germination speed index (IVG); Mean germination time (TMG); Percentage of dead seeds (SM); Length of seedling (CP); Root length (CR) and shoot length (CPA). The data were submitted to analysis of variance and the means were compared by the Tukey test, at 5% probability, using the statistical program SISVAR 5.1. It was observed that: the germination (G) of the safflower seeds did not differ between any of the substrates, varying between 77.5% and 85.25%; For the first germination count (PCG), mean germination time (TMG), germination velocity index (IVG) and root length (CR), the best substrates were between paper, paper and sand; And the substrates between paper and sand obtained better results for seedling length and shoot length
Yield and validation of the scanner for use in the estimation of number of sunflower grains
The commercial exploitation of sunflower is based on the extraction of oil from the achenes and the bran produced, being one of the most important oil supplying species in the world. The objective of the work was to verify the yield of grains from commercial crops in the sunflower and to validate the method of using the scanner for the seed count. The data were collected in two commercial crops, located in the municipalities of Diamantino-MT and Campo Novo dos Parecis-MT. The variables were evaluated between January and July 2014: grain yield, grain yield components and plant height. The seed count was done manually and through an HP Photosmart C4480 All-in-One Scanner scanner, and the images were processed to estimate the number of seeds per chapter in the Quant.v program. 1.0.2. Grain yield data were correlated with grain yield components. The mass of achenes per chapter showed a significant correlation with grain yield. In order to calibrate the digitized images, 1190 and 1107 seeds in the agrobel and aguara varieties, respectively, are adequate, and the seed counting method with the digitizer is accurate and can replace the manual method, in addition, it allows to work with larger samples of achenes per chapter with less time spent
Is Dosing of Ethambutol as Part of a Fixed-Dose Combination Product Optimal for Mechanically Ventilated ICU Patients with Tuberculosis? A Population Pharmacokinetic Study
Background: Tuberculosis (TB) patients admitted to intensive care units (ICU) have high mortality rates. It is uncertain whether the pharmacokinetics of first-line TB drugs in ICU patients are different from outpatients. This study aims to compare the pharmacokinetics of oral ethambutol in TB patients in ICU versus TB outpatients and to determine whether contemporary dosing regimens achieve therapeutic exposures. Methods: A prospective population pharmacokinetic study of ethambutol was performed in Amazonas State, Brazil. Probability of target attainment was determined using AUC/MIC > 11.9 and Cmax/MIC > 0.48 values. Optimized dosing regimens were simulated at steady state. Results: Ten ICU patients and 20 outpatients were recruited. Ethambutol pharmacokinetics were best described using a two-compartment model with first-order oral absorption. Neither ICU patients nor outpatients consistently achieved optimal ethambutol exposures. The absorption rate for ethambutol was 2-times higher in ICU patients (p < 0.05). Mean bioavailability for ICU patients was >5-times higher than outpatients (p < 0.0001). Clearance and volume of distribution were 93% (p < 0.0001) and 53% (p = 0.002) lower in ICU patients, respectively. Conclusions: ICU patients displayed significantly different pharmacokinetics for an oral fixed-dose combination administration of ethambutol compared to outpatients, and neither patient group consistently achieved pre-defined therapeutic exposures
Circadian rhythm-dependent and circadian rhythm-independent impacts of the molecular clock on type 3 innate lymphoid cells
Many gut functions are attuned to circadian rhythm. Intestinal group 3 innate lymphoid cells (ILC3s) include NKp46(+) and NKp46(-) subsets, which are ROR gamma t dependent and provide mucosal defense through secretion of interleukin-22 (IL-22) and IL-17. Because ILC3s highly express some key circadian clock genes, we investigated whether ILC3s are also attuned to circadian rhythm. We noted circadian oscillations in the expression of clock and cytokine genes, such as REV-ERB alpha, IL-22, and IL-17, whereas acute disruption of the circadian rhythm affected cytokine secretion by ILC3s. Because of prominent and rhythmic expression of REV-ERB alpha in ILC3s, we also investigated the impact of constitutive deletion of REV-ERB alpha, which has been previously shown to inhibit the expression of a ROR gamma t repressor, NFIL3, while also directly antagonizing DNA binding of ROR gamma t. Development of the NKp46(+) ILC3 subset was markedly impaired, with reduced cell numbers, ROR gamma t expression, and IL-22 production in REV-ERB alpha-deficient mice. The NKp46(-) ILC3 subsets developed normally, potentially due to compensatory expression of other clock genes, but IL-17 secretion paradoxically increased, probably because ROR gamma t was not antagonized by REV-ERB alpha. We conclude that ILC3s are attuned to circadian rhythm, but clock regulator REV-ERB alpha also has circadian-independent impacts on ILC3 development and functions due to its roles in the regulation of ROR gamma t440FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULO - FAPESP2018/10165-0This study was supported by NIH grants AI095542, DE025884, and AI134236 (to M.C.); AI134035 (to M.C. and E.M.O.); MH092769 (to T.P.B.); K99 DK118110 (to J.K.B.); and T32 GM007200 (to Q.W.). J.L.F. was supported by FAPESP (2018/10165-0). M.C. receives research support from Pfizer, Crohnâs & Colitis Foundation, and anonymous donors, N
Is the Pharmacokinetics of First-Line Anti-TB Drugs a Cause of High Mortality Rates in TB Patients Admitted to the ICU? A Non-Compartmental Pharmacokinetic Analysis
Background: Patients with tuberculosis (TB) may develop multi-organ failure and require admission to intensive care. In these cases, the mortality rates are as high as 78% and may be caused by suboptimal serum concentrations of first-line TB drugs. This study aims to compare the pharmacokinetics of oral rifampin, isoniazid, pyrazinamide and ethambutol patients in intensive care units (ICU) to outpatients and to evaluate drug serum concentrations as a potential cause of mortality. Methods: A prospective pharmacokinetic (PK) study was performed in Amazonas State, Brazil. The primary PK parameters of outpatients who achieved clinical and microbiological cure were used as a comparative target in a non-compartmental analysis. Results: Thirteen ICU and twenty outpatients were recruited. The clearance and volume of distribution were lower for rifampin, isoniazid, pyrazinamide and ethambutol. ICU thirty-day mortality was 77% versus a cure rate of 89% in outpatients. Conclusions: ICU patients had a lower clearance and volume of distribution for rifampin, isoniazid, pyrazinamide and ethambutol compared to the outpatient group. These may reflect changes to organ function, impeded absorption and distribution to the site of infection in ICU patients and have the potential to impact clinical outcomes