4,061 research outputs found
Geographical variation in antimicrobial use and multiresistant pathogens in Brazilian intensive care units: a nationwide study
Introduction: Geographical analyses of antibiotic use identify regions with the highest consumption and help design policies for strategic patient groups.Methodology: We conducted a cross-sectional study based on official data available in July 2022 from Brazilian Health Surveillance Agency (Anvisa). Antibiotics are reported as a defined daily dose (DDD) per 1,000 patient-days, and central line-associated bloodstream infection (CLABSI) is defined according to Anvisa criteria. We also considered multi-drug resistant (MDR) as the critical pathogens the World Health Organization listed. We measured antimicrobial use and CLABSI trends per ICU bed using the compound annual growth rate (CAGR). Results: we evaluated the regional variation in CLABSI by multidrug-resistant pathogens and the antimicrobial use in 1,836 hospital intensive care units (ICUs). In 2020, the leader in use in intensive care units (ICUs) in the North was piperacillin/tazobactam (DDD = 929.7) in the Northeast. Midwest and South were meropenem (DDD = 809.4 and DDD = 688.1, respectively), and Southeast was ceftriaxone (DDD = 751.1). The North has reduced polymyxin use (91.1%), and ciprofloxacin increased (439%) in the South. There was an increase in CLABSI by carbapenem-resistant Pseudomonas aeruginosa in the North region (CAGR = 120.5%). Otherwise, CLABSI by vancomycin-resistant Enterococcus faecium (VRE) increased in all regions except the North (CAGR =-62.2%), while that carbapenem-resistant Acinetobacter baumannii increased in the Midwest (CAGR = 27.3%). Conclusions: we found heterogeneity in antimicrobial use patterns and CLABSI etiology among Brazilian ICUs. Although Gram-negative bacilli were the primary responsible agent, we observed a notable increase trend of CLABSI by VRE
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Suppression of erythropoiesis by dietary nitrate.
In mammals, hypoxia-triggered erythropoietin release increases red blood cell mass to meet tissue oxygen demands. Using male Wistar rats, we unmask a previously unrecognized regulatory pathway of erythropoiesis involving suppressor control by the NO metabolite and ubiquitous dietary component nitrate. We find that circulating hemoglobin levels are modulated by nitrate at concentrations achievable by dietary intervention under normoxic and hypoxic conditions; a moderate dose of nitrate administered via the drinking water (7 mg NaNOā/kg body weight/d) lowered hemoglobin concentration and hematocrit after 6 d compared with nonsupplemented/NaCl-supplemented controls. The underlying mechanism is suppression of hepatic erythropoietin expression associated with the downregulation of tissue hypoxia markers, suggesting increased pOā. At higher nitrate doses, however, a partial reversal of this effect occurred; this was accompanied by increased renal erythropoietin expression and stabilization of hypoxia-inducible factors, likely brought about by the relative anemia. Thus, hepatic and renal hypoxia-sensing pathways act in concert to modulate hemoglobin in response to nitrate, converging at an optimal minimal hemoglobin concentration appropriate to the environmental/physiologic situation. Suppression of hepatic erythropoietin expression by nitrate may thus act to decrease blood viscosity while matching oxygen supply to demand, whereas renal oxygen sensing could act as a brake, averting a potentially detrimental fall in hematocrit.This work was supported by British Heart Foundation Studentship FS/09/050 (to T.A.). A.J.M. thanks the Research Councils UK for supporting his academic fellowship and the WYNG Foundation of Hong Kong for support. J.L.G is supported by the European Union Framework 7 Inheritance project, R.S.J. is supported by a Wellcome Trust Principal research fellowship, and M.F. is supported by funds from the Faculty of Medicine, University of Southampton
Anisotropic crack propagation and deformation in dentin observed by four-dimensional X-ray nano-computed tomography
Understanding the cracking behaviour of biological composite materials is of practical importance. This paper presents the first study to track the interplay between crack initiation, microfracture and plastic deformation in three dimensions (3D) as a function of tubule and collagen fibril arrangement in elephant dentin using in situ X-ray nano-computed tomography (nano-CT). A nano-indenter with a conical tip has been used to incrementally indent three test-pieces oriented at 0Ā°, 45Ā° and 70Ā° to the long axis of the tubules (i.e. radial to the tusk). For the 0Ā° sample two significant cracks formed, one of which linked up with microcracks in the axial-radial plane of the tusk originating from the tubules and the other one occurred as a consequence of shear deformation at the tubules. The 70Ā° test-piece was able to bear the greatest loads despite many small cracks forming around the indenter. These were diverted by the microstructure and did not propagate significantly. The 45Ā° test-piece showed intermediate behaviour. In all cases strains obtained by digital volume correlation were well in excess of the yield strain (0.9%), indeed some plastic deformation could even be seen through bending of the tubules. The hoop strains around the conical indenter were anisotropic with the smallest strains correlating with the primary collagen orientation (axial to the tusk) and the largest strains aligned with the hoop direction of the tusk
Transcatheter indirect mitral annuloplasty induces annular and left atrial remodelling in secondary mitral regurgitation
Aims
Mitral annuloplasty using the Carillon Mitral Contour System (CMCS) reduces secondary mitral regurgitation (SMR) and leads to reverse left ventricular remodelling. The aim of this study was to evaluate the effect of the CMCS on the mitral valve annulus (MA) and left atrial volume (LAV).
Methods and results
We retrospectively evaluated the data of all patients treated with the CMCS at our centre. Using transthoracic echocardiography, MA diameters were assessed by measuring the anterolateral to posteromedial extend (ALPM) and the anterior to posterior (AP) dimensions, respectively. Also, LAV and left ventricular endādiastolic volume (LVEDV) were assessed. Patients were examined at three time points: baseline, at 20ā60 days (30dFUP), and at 9ā15 months (1yFUP), using paired analysis. From July 2014 until March 2019, 75 cases of severe SMR were treated using CMCS. Cases in which other devices were used in combination (COMBO therapy, n = 35) or in which the device could not be implanted (implant failure, n = 3) were excluded, leaving 37 patients in the present analysis. Analysis at 30dFUP showed a significant reduction of 16% in the mean ALPM diameter (7.27 Ā± 5.40 mm) and 15% in the AP diameter (6.57 Ā± 5.33 mm). Analysis of LAV also showed a significant reduction of 21% (36.61 Ā± 82.67 mL), with no significant change in LVEDV. At 1yFUP, the reduction of both the mean ALPM diameter of 14% (6.24 Ā± 5.70 mm) and the mean AP diameter of 12% (5.46 Ā± 4.99 mm) remained significant and stable. The reduction in LAV was also maintained at 23% (37.03 Ā± 56.91 mL). LAV index was significantly reduced by 17% at 30dFUP (15.44 Ā± 40.98 mL/m2) and by 13% at 1yFUP (11.56 Ā± 31.87 mL/m2), respectively. LVEDV index showed no significant change at 30dFUP and a nonāsignificant 10% reduction at 1yFUP (17.75 Ā± 58.79 mL/m2).
Conclusions
The CMCS successfully treats symptomatic SMR with a stable reduction of not only the AP diameter of the MA, but the current study also demonstrates an additional reduction of the ALPM dimension at both 30dFUP and 1yFUP. We have also shown for the first time that LAV and LAV index are significantly reduced at both 30dFUP and 1yFUP and a nonāsignificant positive remodelling of the LVEDV. This positive left atrial remodelling has not been looked for and demonstrated in earlier randomized studies of CMCS
Super-resolution far-field ghost imaging via compressive sampling
Much more image details can be resolved by improving the system's imaging
resolution and enhancing the resolution beyond the system's Rayleigh
diffraction limit is generally called super-resolution. By combining the sparse
prior property of images with the ghost imaging method, we demonstrated
experimentally that super-resolution imaging can be nonlocally achieved in the
far field even without looking at the object. Physical explanation of
super-resolution ghost imaging via compressive sampling and its potential
applications are also discussed.Comment: 4pages,4figure
Origin of the cataclysmic Late Heavy Bombardment period of the terrestrial planets
Nature, 435, pp. 466-469, http://dx.doi.org./10.1038/nature03676International audienc
The Rho family GEF FARP2 is activated by aPKC iota to control tight junction formation and polarity
The elaboration of polarity is central to organismal development and to the maintenance of functional epithelia. Among the controls determining polarity are the PAR proteins, PAR6, aPKCĪ¹ and PAR3, regulating both known and unknown effectors. Here, we identify FARP2 as a āRIPRā motif-dependent partner and substrate of aPKCĪ¹ that is required for efficient polarisation and junction formation. Binding is conferred by a FERM/FA domainākinase domain interaction and detachment promoted by aPKCĪ¹-dependent phosphorylation. FARP2 is shown to promote GTP loading of Cdc42, which is consistent with it being involved in upstream regulation of the polarising PAR6āaPKCĪ¹ complex. However, we show that aPKCĪ¹ acts to promote the localised activity of FARP2 through phosphorylation. We conclude that this aPKCĪ¹āFARP2 complex formation acts as a positive feedback control to drive polarisation through aPKCĪ¹ and other Cdc42 effectors
The effectiveness of public health interventions to reduce the health impact of climate change:a systematic review of systematic reviews
Climate change is likely to be one of the most important threats to public health in the coming years. Yet despite the large number of papers considering the health impact of climate change, few have considered what public health interventions may be of most value in reducing the disease burden. We aimed to evaluate the effectiveness of public health interventions to reduce the disease burden of high priority climate sensitive diseases
Wolbachia and DNA barcoding insects: patterns, potential and problems
Wolbachia is a genus of bacterial endosymbionts that impacts the breeding systems of their hosts. Wolbachia can confuse the patterns of mitochondrial variation, including DNA barcodes, because it influences the pathways through which mitochondria are inherited. We examined the extent to which these endosymbionts are detected in routine DNA barcoding, assessed their impact upon the insect sequence divergence and identification accuracy, and considered the variation present in Wolbachia COI. Using both standard PCR assays (Wolbachia surface coding protein ā wsp), and bacterial COI fragments we found evidence of Wolbachia in insect total genomic extracts created for DNA barcoding library construction. When >2 million insect COI trace files were examined on the Barcode of Life Datasystem (BOLD) Wolbachia COI was present in 0.16% of the cases. It is possible to generate Wolbachia COI using standard insect primers; however, that amplicon was never confused with the COI of the host. Wolbachia alleles recovered were predominantly Supergroup A and were broadly distributed geographically and phylogenetically. We conclude that the presence of the Wolbachia DNA in total genomic extracts made from insects is unlikely to compromise the accuracy of the DNA barcode library; in fact, the ability to query this DNA library (the database and the extracts) for endosymbionts is one of the ancillary benefits of such a large scale endeavor ā for which we provide several examples. It is our conclusion that regular assays for Wolbachia presence and type can, and should, be adopted by large scale insect barcoding initiatives. While COI is one of the five multi-locus sequence typing (MLST) genes used for categorizing Wolbachia, there is limited overlap with the eukaryotic DNA barcode region
Abiotic conditions in cephalopod (Sepia officinalis) eggs: embryonic development at low pH and high pCO2
Low pO(2) values have been measured in the perivitelline fluids (PVF) of marine animal eggs on several occasions, especially towards the end of development, when embryonic oxygen consumption is at its peak and the egg case acts as a massive barrier to diffusion. Several authors have therefore suggested that oxygen availability is the key factor leading to hatching. However, there have been no measurements of PVF pCO(2) so far. This is surprising, as elevated pCO(2) could also constitute a major abiotic stressor for the developing embryo. As a first attempt to fill this gap in knowledge, we measured pO(2), pCO(2) and pH in the PVF of late cephalopod (Sepia officinalis) eggs. We found linear relationships between embryo wet mass and pO(2), pCO(2) and pH. pO(2) declined from > 12 kPa to less than 5 kPa, while pCO(2) increased from 0.13 to 0.41 kPa. In the absence of active accumulation of bicarbonate in the PVF, pH decreased from 7.7 to 7.2. Our study supports the idea that oxygen becomes limiting in cephalopod eggs towards the end of development; however, pCO(2) and pH shift to levels that have caused significant physiological disturbances in other marine ectothermic animals. Future research needs to address the physiological adaptations that enable the embryo to cope with the adverse abiotic conditions in their egg environment
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