513 research outputs found
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Bifidobacterial Dominance of the Gut in Early Life and Acquisition of Antimicrobial Resistance.
Bifidobacterium species are important commensals capable of dominating the infant gut microbiome, in part by producing acids that suppress growth of other taxa. Bifidobacterium species are less prone to possessing antimicrobial resistance (AMR) genes (ARGs) than other taxa that may colonize infants. Given that AMR is a growing public health crisis and ARGs are present in the gut microbiome of humans from early life, this study examines the correlation between a Bifidobacterium-dominated infant gut microbiome and AMR levels, measured by a culture-independent metagenomic approach both in early life and as infants become toddlers. In general, Bifidobacterium dominance is associated with a significant reduction in AMR in a Bangladeshi cohort, both in the number of acquired AMR genes present and in the abundance of AMR genes. However, by year 2, Bangladeshi infants had no significant differences in AMR related to their early-life Bifidobacterium levels. A generalized linear model including all infants in a previously published Swedish cohort found a significant negative association between log-transformed total AMR and Bifidobacterium levels, thus confirming the relationship between Bifidobacterium levels and AMR. In both cohorts, there was no change between early-life and later-life AMR abundance in high-Bifidobacterium infants but a significant reduction in AMR abundance in low-Bifidobacterium infants. These results support the hypothesis that early Bifidobacterium dominance of the infant gut microbiome may help reduce colonization by taxa containing ARGs.IMPORTANCE Infants are vulnerable to an array of infectious diseases, and as the gut microbiome may serve as a reservoir of AMR for pathogens, reducing the levels of AMR in infants is important to infant health. This study demonstrates that high levels of Bifidobacterium are associated with reduced levels of AMR in early life and suggests that probiotic interventions to increase infant Bifidobacterium levels have the potential to reduce AMR in infants. However, this effect is not sustained at year 2 of age in Bangladeshi infants, underscoring the need for more detailed studies of the biogeography and timing of infant AMR acquisition
Inexpensive current-voltage system with electronically-controlled resistance under xenon arc light for solar cell efficiency measurements
Crystalline silicon solar cell efficiency is required in order to accurately determine its performance and evaluate the fabrication process. Extensive automation has led to development of expensive instrumentation. In this study, simple, inexpensive method for measuring solar cell efficiency is reported. A controllable direct current (dc) illumination intensity method based on low power xenon arc lamps was designed and constructed. Low resistance electrical contacts were formed with conventional front surface probes and back surface Au-plated metal plate with vacuum attachment. In order to measure current-voltage (I-V) response, variable resistance approach was chosen. Commercially available, low cost electronic loads power supply is used to precisely vary resistance while measuring cell voltage and current. The resistance is controllably varied from a short circuit to an open circuit position on the I-V curve while measuring cell voltage and current. Plotting current as a function of voltage generates the characteristic solar cell I-V response. Solar cell efficiency measurements were recorded and plotted using LabVIEW program. The light intensity was varied by increasing number of high intensity discharge (HID) 50 W from 1 to four in order to vary respective illumination intensities from 330 to 1200 W/m2 range. The variation in light intensity was aimed at investigation of the electronic loads power supply at low and high currents. This I-V tester has been applied to different types of solar cell to validate its performance. Solar cells measured as part of this study included commercial silicon solar cell and laboratory solar cells with phosphorus oxytrichloride (POCl3) and phosphoric acid (H3PO4) emitter formation. This I-V measurement system for commercial cell exhibited an efficiency of 15.83% and efficiency of 16.2% and 13.3% for solar cells with POCl3 and H3PO emitters
Design, Synthesis and Biological Evaluation of Novel Pyrimido[4,5-d]pyrimidine CDK2 Inhibitors as Anti-Tumor Agents
A series of 2,5,7-trisubstituted pyrimido[4,5-d]pyrimidine cyclin-dependent kinase (CDK2) inhibitors is designed and synthesized. 6-Amino-2-thiouracil is reacted with an aldehyde and thiourea to prepare the pyrimido[4,5-d]-pyrimidines. Alkylation and amination of the latter ones give different amino derivatives. These compounds show potent and selective CDK inhibitory activities and inhibit in vitro cellular proliferation in cultured human tumor cells
BrightOcular® Cosmetic Iris Implant: A Spectrum from Tolerability to Severe Morbidity
Purpose: The BrightOcular® implants are the newest model of cosmetic iris devices that are currently advertised as safe. The previous generation known as NewColorIris® have had severe ocular side effects and were subsequently withdrawn from the market. There is little literature on the safety profile of BrightOcular® implants. Case Report: Herein we describe two cases with varying degrees of ocular tolerability. The first case had a normal ocular exam 1 year after implantation, whereas the second case had unilateral severe corneal edema requiring explantation of the iris device and Descemet membrane endothelial keratoplasty 9 months after bilateral implantation. Conclusions: These two cases attest to the unpredictability of the results of these cosmetic surgeries. Patients should be counseled about the vision-threatening complications of iris implants
Drawing as a process of psychic mediation along the child´s developmental trajectory
This is an open-access article distributed under the terms and conditions of the Creative Commons Attribution
license (http://creativecommons.org/licenses/by/4.0/).INTRODUCTION: The intrapsychic process of resorting to the symbolic is innate and prepares the child for the organization of his internal world. Throughout the child's developmental trajectory, its playful projective expression, allows us to assess the psychographically internalized stages of development. The present study aims to evaluate the mental representation of the concept of symbolism, size, and perspective of designed percepts along the developmental trajectory (age range from 4 to 12 years).METHODS: Patients were invited to produce two drawings depicting a Healthy Tooth and an Unhealthy Tooth. The qualitative content grid for the analysis of the drawings was originally designed to study the pictorial representations found in the sample. However, in this article, we only intend to present the results obtained regarding Symbolism, Size and Perspective categories that are part of the content analysis grid.RESULTS: Regarding the Symbolism Category, most respondents between 4 and 6 years of age, pictorially represented an Unrealistic Tooth, and from 10 years onwards there is a marked decrease in this pictorial (Un)Realism. Regarding the Size of Teeth Category, from 8 years old onwards the drawings seem to increase in terms of their dimension. When it comes to Perspective Category, the percept drawn in a 2D perspective clearly prevails, regardless of age.CONCLUSION: Results obtained in this study show that the mental representation of (Un)Healthy teeth are early internalized during childhood and the stages of psychographic development seem to be reliable indicators of the development of the mental representation of the child´s symbolism.info:eu-repo/semantics/publishedVersio
Art students: do they really draw what they know about the inner body?
The aim of the present study was to examine seven case studies and ascertain whether the imagos internalized by students of Fine Arts, a Young Person and an Elderly Person can be reworked, after the students have been submitted to a course in Anatomy. In the present study, we have combined two methods - gathering written responses and drawings - and examined what students know about the organs they drew and used a content analysis grid to evaluate the mental representation of the interior of the body of both profiles (Young Person and Elderly Person), before and after academic training (Anatomy classes). The preliminary data collected provided a prima facie scenario for the existence of at least one sequencial comulative progression in the development of the art students drawings. However further research is needed to establish the extent to which this finding might apply beyond the tasks assigned in the present protocol.info:eu-repo/semantics/publishedVersio
Mixed RIS-Relay NOMA-Based RF-UOWC systems
Reconfigurable intelligent surface (RIS), nonorthogonal
multiple access (NOMA), and underwater optical
wireless communication (UOWC) are paradigms of technologies
that drive the development of communications nowadays. In this
paper, we investigate the performance of a NOMA-based RISassisted
hybrid radio frequency (RF)-UOWC system. Due to the
interruption of the direct link between the base station and the
ship floating on the surface of the water, communication will
be carried out via an RIS fixed to an intermediate building.
The ship works as a relay that redirects the received signal to
two underwater destinations simultaneously. In this paper, we
provide new analytical expressions for the outage probability
(OP), asymptotic analyses of the OP, and diversity order (D) to
gain insights into the system performance. The results showed
that the diversity order depends on the UOWC receiver detection
technique. In the end, we illustrated that the NOMA-based RISassisted
system significantly improves the outage performance of
hybrid RF-UWOC systems over a benchmark systems
Symbiotic ambient backscatter IoT transmission over NOMA-enabled network
Non-orthogonal multiple access (NOMA) and ambient backscatter communication (AmBC) play major roles to enhance spectrum efficiency in wireless communication systems. Besides, the AmBC provides good reinforcement for the current trend towards dispensing batteries for battery-free Internet-of-Things (IoT) devices. In this paper, we propose a symbiotic battery-free IoT system, that exploits the downlink transmission of a NOMA multiplexing enabled cellular network, to permit an IoT spectrum-efficient uplink communication. The IoT backscatter device (BD) performs a symbiotic radio (SR) relation with the cellular source to power its communication by intelligently reflecting the received power. We derive a closed-form expression of the ergodic capacity (EC) of the BD transmission and tight approximations of the ECs of the cellular source transmission, where all channels undergo Nakagami-m fading. Additionally, we validate the analytical results obtained using Monte-Carlo simulations. The influences of several system parameters such as power allocation factor, reflection coefficient, and channels' severity factors have been investigated. Finally, the performance of the proposed system is compared with a benchmark OMA-based system to highlight the achievable performance improvement
Measuring Coverage in MNCH:A Prospective Validation Study in Pakistan and Bangladesh on Measuring Correct Treatment of Childhood Pneumonia
Antibiotic treatment for pneumonia as measured by Demographic and Health Surveys (DHS) and Multiple Indicator Cluster Surveys (MICS) is a key indicator for tracking progress in achieving Millennium Development Goal 4. Concerns about the validity of this indicator led us to perform an evaluation in urban and rural settings in Pakistan and Bangladesh.Caregivers of 950 children under 5 y with pneumonia and 980 with "no pneumonia" were identified in urban and rural settings and allocated for DHS/MICS questions 2 or 4 wk later. Study physicians assigned a diagnosis of pneumonia as reference standard; the predictive ability of DHS/MICS questions and additional measurement tools to identify pneumonia versus non-pneumonia cases was evaluated. Results at both sites showed suboptimal discriminative power, with no difference between 2- or 4-wk recall. Individual patterns of sensitivity and specificity varied substantially across study sites (sensitivity 66.9% and 45.5%, and specificity 68.8% and 69.5%, for DHS in Pakistan and Bangladesh, respectively). Prescribed antibiotics for pneumonia were correctly recalled by about two-thirds of caregivers using DHS questions, increasing to 72% and 82% in Pakistan and Bangladesh, respectively, using a drug chart and detailed enquiry.Monitoring antibiotic treatment of pneumonia is essential for national and global programs. Current (DHS/MICS questions) and proposed new (video and pneumonia score) methods of identifying pneumonia based on maternal recall discriminate poorly between pneumonia and children with cough. Furthermore, these methods have a low yield to identify children who have true pneumonia. Reported antibiotic treatment rates among these children are therefore not a valid proxy indicator of pneumonia treatment rates. These results have important implications for program monitoring and suggest that data in its current format from DHS/MICS surveys should not be used for the purpose of monitoring antibiotic treatment rates in children with pneumonia at the present time
Morphological and imaging evaluation of the metacarpophalangeal and metatarsophalangeal joints in healthy and lame donkeys
The donkey is of socio-economic value yet imaging techniques in both healthy and abnormal limbs are a limiting factor in research and medicine. The objective was to determine anatomical features of both healthy and clinically abnormal donkey metacarpophalangeal and metatarsophalangeal joints (n=13) using anatomical dissection, casting, x-ray and computed tomography. The joint capsule contained two palmar/plantar and two dorsal recesses. The proximal-palmar or plantar recess was larger than the distodorsal recess and potential sites of approaches to the recesses were determined. Soft tissue structures were distinguished using computed tomography at 300mA which was superior to 120mA. This methodology gave better assessments of the synovial tendon sheath, joint recesses and cruciate, collateral and short sesamoidean ligaments. Computed tomography provided outstanding discrimination between the cortex and medulla of the third metacarpal, the proximal sesamoid bones, the proximal phalanx and excellent details of the osseous structures. Although the joints appeared free from exostosis using x-ray; the position and extension of exostosis in pathologically affected donkeys (a novel finding) was revealed using computed tomography with 300mA in comparison to 120mA. The study also provided an anatomical record of the metacarpophalangeal and metatarsophalangeal joints using the latest technology which could impact on clinical situations including anesthesia injection sites
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