122 resultados para Ag recovery
Resumo:
Biomaterials releasing silver (Ag) are of interest because of their ability to inhibit pathogenic bacteria including antibiotic-resistant strains. In order to investigate the potential of nanometre-thick Ag polymer (Ag/amino-hydrocarbon) nanocomposite plasma coatings, we studied a comprehensive range of factors such as the plasma deposition process and Ag cation release as well as the antibacterial and cytocompatible properties. The nanocomposite coatings released most bound Ag within the first day of immersion in water yielding an antibacterial burst. The release kinetics correlated with the inhibitory effects on the pathogens Pseudomonas aeruginosa or Staphylococcus aureus and on animal cells that were in contact with these coatings. We identified a unique range of Ag content that provided an effective antibacterial peak release, followed by cytocompatible conditions soon thereafter. The control of the in situ growth conditions for Ag nanoparticles in the polymer matrix offers the possibility to produce customized coatings that initially release sufficient quantities of Ag ions to produce a strong adjacent antibacterial effect, and at the same time exhibit a rapidly decaying Ag content to provide surface cytocompatibility within hours/days. This approach seems to be favourable with respect to implant surfaces and possible Ag-resistance/tolerance built-up.
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BACKGROUND: Protocols for enhanced recovery provide comprehensive and evidence-based guidelines for best perioperative care. Protocol implementation may reduce complication rates and enhance functional recovery and, as a result of this, also reduce length-of-stay in hospital. There is no comprehensive framework available for pancreaticoduodenectomy. METHODS: An international working group constructed within the Enhanced Recovery After Surgery (ERAS(®)) Society constructed a comprehensive and evidence-based framework for best perioperative care for pancreaticoduodenectomy patients. Data were retrieved from standard databases and personal archives. Evidence and recommendations were classified according to the GRADE system and reached through consensus in the group. The quality of evidence was rated "high", "moderate", "low" or "very low". Recommendations were graded as "strong" or "weak". RESULTS: Comprehensive guidelines are presented. Available evidence is summarised and recommendations given for 27 care items. The quality of evidence varies substantially and further research is needed for many issues to improve the strength of evidence and grade of recommendations. CONCLUSIONS: The present evidence-based guidelines provide the necessary platform upon which to base a unified protocol for perioperative care for pancreaticoduodenectomy. A unified protocol allows for comparison between centres and across national borders. It facilitates multi-institutional prospective cohort registries and adequately powered randomised trials.
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To report a case of clinical and electrophysiological recovery in Leber hereditary optic neuropathy (LHON) with G3460A Mutation. A 10-year-old boy with a three-month history of painless bilateral sequential visual loss upon presentation underwent visual acuity (diminished), anterior and posterior segment examination (normal), fluorescein angiography (normal), Goldman kinetic perimetry (bilateral central scotomata), genetic (a point G3460A mutation) and electrophysiological investigation (undetectable pattern visual evoked potentials (VEP); low amplitude, broadened and reduced flash VEPs and loss of the N95 component in the pattern electroretinograms). Diagnosis of LHON was made. Eighteen months later vision and electrophysiological tests results began spontaneously improving. Kinetic perimetry revealed reduced density and size of scotomata. Two years later, there had been further electrophysiological improvement. This report describes both clinical and electrophysiological improvement in LHON with G3460A mutation.
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Introduction: Prior repeated-sprints (6) has become an interesting method to resolve the debate surrounding the principal factors that limits the oxygen uptake (V'O2) kinetics at the onset of exercise [i.e., muscle O2 delivery (5) or metabolic inertia (3)]. The aim of this study was to compare the effects of two repeated-sprints sets of 6x6s separated by different recovery duration between the sprints on V'O2 and muscular de-oxygenation [HHb] kinetics during a subsequent heavy-intensity exercise. Methods: 10 male subjects performed a 6-min constant-load cycling test (T50) at intensity corresponding to half of the difference between V'O2max and the ventilatory threshold. Then, they performed two repeated-sprints sets of 6x6s all-out separated by different recovery duration between the sprints (S1:30s and S2:3min) followed, after 7-min-recovery, by the T50 (S1T50 and S2T50, respectively). V'O2, [HHb] of the vastus lateralis (VL) and surface electromyography activity [i.e., root-mean-square (RMS) and the median frequency of the power density spectrum (MDF)] from VL and vastus medialis (VM) were recorded throughout T50. Models using a bi-exponential function for the overall T50 and a mono-exponential for the first 90s of T50 were used to define V'O2 and [HHb] kinetics respectively. Results: V'O2 mean value was higher in S1 (2.9±0.3l.min-1) than in S2 (1.2±0.3l.min-1); (p<0.001). The peripheral blood flow was increased after sprints as attested by a higher basal heart rate (HRbaseline) (S1T50: +22%; S2T50: +17%; p≤0.008). Time delay [HHb] was shorter for S1T50 and S2T50 than for T50 (-22% for both; p≤0.007) whereas the mean response time of V'O2 was accelerated only after S1 (S1T50: 32.3±2.5s; S2T50: 34.4±2.6s; T50: 35.7±5.4s; p=0.031). There were no significant differences in RMS between the three conditions (p>0.05). MDF of VM was higher during the first 3-min in S1T50 than in T50 (+6%; p≤0.05). Conclusion: The study show that V'O2 kinetics was speeded by prior repeated-sprints with a short (30s) but not a long (3min) inter-sprints-recovery even though the [HHb] kinetics was accelerated and the peripheral blood flow was enhanced after both sprints. S1, inducing a greater PCr depletion (1) and change in the pattern of the fibres recruitment (increase in MDF) compared with S2, may decrease metabolic inertia (2), stimulate the oxidative phosphorylation activation (4) and accelerate V'O2 kinetics at the beginning of the subsequent high-intensity exercise.
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OBJECTIVES: To determine characteristics associated with single and multiple fallers during postacute rehabilitation and to investigate the relationship among falls, rehabilitation outcomes, and health services use. DESIGN: Retrospective cohort study. SETTING: Geriatric postacute rehabilitation hospital. PARTICIPANTS: Patients (n = 4026) consecutively admitted over a 5-year period (2003-2007). MEASUREMENTS: All falls during hospitalization were prospectively recorded. Collected patients' characteristics included health, functional, cognitive, and affective status data. Length of stay and discharge destination were retrieved from the administrative database. RESULTS: During rehabilitation stay, 11.4% (458/4026) of patients fell once and an additional 6.3% (253/4026) fell several times. Compared with nonfallers, fallers were older and more frequently men. They were globally frailer, with lower Barthel score and more comorbidities, cognitive impairment, and depressive symptoms. In multivariate analyses, compared with 1-time fallers, multiple fallers were more likely to have lower Barthel score (adjOR: 2.45, 95% CI: 1.48-4.07; P = .001), cognitive impairment (adjOR: 1.43, 95% CI: 1.04-1.96; P = .026), and to have been admitted from a medicine ward (adjOR: 1.55, 95% CI: 1.03-2.32; P = .035). Odds of poor functional recovery and institutionalization at discharge, as well as length of stay, increased incrementally from nonfallers to 1-time and to multiple fallers. CONCLUSION: In these patients admitted to postacute rehabilitation, the proportion of fallers and multiple fallers was high. Multiple fallers were particularly at risk of poor functional recovery and increased health services use. Specific fall prevention programs targeting high-risk patients with cognitive impairment and low functional status should be developed in further studies.
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Delayed recovery has been advocated to limit the postoperative stress linked to awakening from anesthesia, but data on this subject are lacking. In this study, we measured oxygen consumption (V(O2)) and plasma catecholamine concentrations as markers of postoperative stress. We tested the hypothesis that delayed recovery and extubation would attenuate metabolic changes after intracranial surgery. Thirty patients were included in a prospective, open study and were randomized into two groups. In Group I, the patients were tracheally extubated as soon as possible after surgery. In Group II, the patients were sedated with propofol for 2 h after surgery. V(O2), catecholamine concentration, mean arterial pressure (MAP), and heart rate (HR) were measured during anesthesia, at extubation, and 30 min after extubation. V(O2) and noradrenaline on extubation and mean V(O2) during recovery were significantly higher in Group II than in Group I (V(O2) for Group I: preextubation 215 +/- 46 mL/min, recovery 198 +/- 38 mL/min; for Group II: preextubation 320 +/- 75 mL/min, recovery 268 +/- 49 mL/min; noradrenaline on extubation for Group I: 207 +/- 76 pg/mL, for Group II: 374 +/- 236 pg/ mL). Extubation induced a significant increase in MAP. MAP, HR, and adrenaline values were not statistically different between groups. In conclusion, delayed recovery after neurosurgery cannot be recommended as a mechanism of limiting the metabolic and hemodynamic consequences from emergence from general anesthesia. IMPLICATIONS: In this study, we tested the hypothesis that delayed recovery after neurosurgery would attenuate the consequences of recovery from general anesthesia. As markers of stress, oxygen consumption and noradrenaline blood levels were higher after delayed versus early recovery. Thus, delayed recovery cannot be recommended as a mechanism of limiting the metabolic and hemodynamic consequences from emergence after neurosurgery.
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BACKGROUND: A major goal of antiretroviral therapy (ART) for HIV-1-infected persons is the recovery of CD4 T lymphocytes, resulting in thorough protection against opportunistic complications. Interruptions of ART are still frequent. The long-term effect on CD4 T-cell recovery and clinical events remains unknown. METHODS: Immunological and clinical endpoints were evaluated in 2491 participants of the Swiss HIV Cohort Study initiating ART during a mean follow-up of 7.1 years. Data were analysed in persons with treatment interruptions (n = 1271; group A), continuous ART, but intermittent HIV-1 RNA at least 1000 copies/ml (n = 469; group B) and continuous ART and HIV-1 RNA constantly less than 1000 copies/ml (n = 751; group C). Risk factors for low CD4 T-cell counts and clinical events were analysed using Cox proportional hazards models. RESULTS: In groups A-C, CD4 T lymphocytes increased to a median of 427, 525 and 645 cells/μl at 8 years. In group A, 63.0 and 37.2% reached above 350 and 500 CD4 T cells/μl, whereas in group B 76.3 and 55.8% and in group C 87.3 and 68.0% reached these thresholds (P < 0.001). CD4 T-cell recovery directly depended on the cumulative duration of treatment interruptions. In addition, participants of group A had more Centers for Disease Control and Prevention B/C events, resulting in an increased risk of death. Major risk factors for not reaching CD4 T cells above 500 cells/μl included lower baseline CD4 T-cell count, higher age and hepatitis C virus co-infection. CONCLUSION: In persons receiving continuous ART larger CD4 T-cell recovery and a reduced risk for opportunistic complications and death was observed. CD4 T-cell recovery was smaller in persons with treatment interruptions more than 6 months.
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BACKGROUND: Enhanced recovery protocols have been proven to decrease complications and hospital stay following elective colorectal surgery. However, these principles have not yet been reported for urgent surgery procedures. We aimed to assess our initial experience with urgent colectomies performed within an established enhanced recovery pathway. METHODS: In a prospective cohort study, all patients undergoing colonic resection between April 2012 and March 2013 were treated according to a standardized enhanced recovery protocol. Urgent surgeries were compared with the elective procedures with regards to baseline characteristics, compliance with enhanced recovery items, and clinical outcome. RESULTS: Patients (N = 28) requiring urgent colonic resection were included and compared with patients undergoing elective colectomy (N = 63). Overall compliance with the protocol was 57% for the urgent compared with 77% for the elective procedures (p = 0.006). The pre-operative compliance was 64 versus 96% (p < 0.001), the intra-operative compliance was 77 versus 86% (p = 0.145), and the post-operative compliance was 49 versus 67% (p = 0.015), for the urgent and elective resections, respectively. Overall, 18 urgent patients (64%) and 32 elective patients (51%) developed postoperative complications (p = 0.261). Median postoperative length of stay was 8 days in the urgent setting compared with 5 days in the elective setting (p = 0.006). CONCLUSIONS: Many of the intra-operative and post-operative enhanced recovery items can also be applied to urgent colectomy, entailing outcomes that approach the results achieved in the elective setting.
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We propose a compressive sensing algorithm that exploits geometric properties of images to recover images of high quality from few measurements. The image reconstruction is done by iterating the two following steps: 1) estimation of normal vectors of the image level curves, and 2) reconstruction of an image fitting the normal vectors, the compressed sensing measurements, and the sparsity constraint. The proposed technique can naturally extend to nonlocal operators and graphs to exploit the repetitive nature of textured images to recover fine detail structures. In both cases, the problem is reduced to a series of convex minimization problems that can be efficiently solved with a combination of variable splitting and augmented Lagrangian methods, leading to fast and easy-to-code algorithms. Extended experiments show a clear improvement over related state-of-the-art algorithms in the quality of the reconstructed images and the robustness of the proposed method to noise, different kind of images, and reduced measurements.
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The breccia-hosted epithermal Au-Ag deposit of Rosia Montana is located 7 kin northeast of Abrud, in the northern part of the South Apuseni Mountains, Romania. Estimated total reserves of 214.91 million metric toils (Mt) of ore at 1.46 g/t An and 6.9 g/t Ag (10.1 Moz of An and 47.6 Moz of Ag) make Rosia Montana one of the largest gold deposits in Europe. At this location, Miocene calc-alkaline magmatic and hydrothermal activity was associated with local extensional tectonics within a strike-slip regime related to the indentation of the Adriatic microplate into the European plate during the Carpathian orogenesis. The host rocks of the magmatic complex consist of pre-Mesozoic metamorphosed continental crust covered by Cretaceous turbiditic sediment (flysch). Magmatic activity at Rosia Montana and its surroundings occurred in several pulses and lasted about 7 m.y, Rosia Montana is a breccia-hosted epithermal system related to strong phreatomagmatic activity due to the shallow emplacement of the Montana dacite. The Montana dacite intruded Miocene volcaniclastic material (volcaniclastic breccias) and crops out at Cetate and Carnic Hills. Current mining is focused primarily on the Cetate open pit, which was mapped in detail, leading to the recognition of three distinct breccia bodies: the dacite breccia with a dominantly hydrothermal matrix, the gray polymict breccia with a greater proportion of sand-sized matrix support, and the black polymict breccia, which reached to the surface, contains carbonized tree trunks and has a dominantly barren elastic matrix. The hydrothermal alteration is pervasive. Adularia alteration with a phyllic overprint is ubiquitous; silicification and argillic alteration occur locally. Mineralization consists of quartz, adularia, carbonates (commonly Mn-rich), pyrite, Fe-poor sphalerite, galena, chalcopyrite, tetrahedrite, and native gold and occurs as disseminations, as well as in veins and filling vugs within the Montana dacite and the different breccias. The age of mineralization (12.85 +/- 0.07 Ma) was determined by Ar-40- Ar-39 dating on hydrothermal adularia crystals from vugs in the dacite breccia in the Cetate open pit. Microthermometric measurements of fluid inclusions in quartz phenocrysts from the Montana dacite revealed two fluid types that are absent from the hydrothermal breccia and must have been trapped at depth prior to dacite dome emplacement: brine inclusions (32-55 -wt % NaCl equiv, homogenizing at T-h > 460 degrees C) and intermediate density fluids (4.9-15.6 wt % NaCl equiv, T, between 345 degrees-430 degrees C). Secondary aqueous fluid inclusion assemblages in the phenocrysts have salinities of 0.2 to 2.2 wt percent NaCl equiv and T-h of 200 degrees to 280 degrees C. Fluid inclusion assemblages in hydrothermal quartz from breccias and veins have salinities of 0.2 to 3.4 wt percent NaCl equiv and T-h, from 200 degrees to 270 degrees C. The oxygen isotope composition of several zones of an ore-related epithermal quartz crystal indicate a very constant delta O-18 of 4.5 to 5.0 per mil for the mineralizing fluid, despite significant salinity and temperature variation over time. Following microthermometry, selected fluid inclusion assemblages were analyzed by laser ablation-inductively coupled-plasma mass spectrometry (LA-ICMS). Despite systematic differences in salinity between phenocryst-hosted fluids trapped at depth and fluids from quartz in the epithermal breccias, all fluids have overlapping major and trace cation ratios, including identical Na/K/Rb/Sr/Cs/Ba. Consistent with the constant near-magmatic oxygen isotope composition of the hydrothermal fluids, these data strongly indicate a common magmatic component of these chemically conservative solutes in all fluids. Cu, Pb, Zn, and Mn show variations in concentration relative to the relatively non-reactive alkalis, reflecting the precipitation of sulfide minerals together with An in the epithermal breccia, and possibly of Cu in an inferred subjacent porphyry environment. The magmatic-hydrothermal processes responsible for epithermal Au-Ag mineralization at Rosia Montana are, however, not directly related to the formation of the spatially associated porphyry Cu-Au deposit of Rosia Poieni, which occurred lout 3 m.y. later.
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Wild-type A75/17-Canine distemper virus (CDV) is a highly virulent strain, which induces a persistent infection in the central nervous system (CNS) with demyelinating disease. Wild-type A75/17-CDV, which is unable to replicate in cell lines to detectable levels, was adapted to grow in Vero cells and was designated A75/17-V. Sequence comparison between the two genomes revealed seven nucleotide differences located in the phosphoprotein (P), the matrix (M) and the large (L) genes. The P gene is polycistronic and encodes two auxiliary proteins, V and C, besides the P protein. The mutations resulted in amino acid changes in the P and V, but not in the C protein, as well as in the M and L proteins. Here, a rescue system was developed for the A75/17-V strain, which was shown to be attenuated in vivo, but retains a persistent infection phenotype in Vero cells. In order to track the recombinant virus, an additional transcription unit coding for the enhanced green fluorescent protein (eGFP) was inserted at the 3' proximal position in the A75/17-V cDNA clone. Reverse genetics technology will allow us to characterize the genetic determinants of A75/17-V CDV persistent infection in cell culture.
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OBJECTIVE: To examine characteristics associated with functional recovery in older patients undergoing postacute rehabilitation. DESIGN: Observational study. SETTING: Postacute rehabilitation facility. PARTICIPANTS: Patients (N=2754) aged ≥65 years admitted over a 4-year period. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Functional status was assessed at admission and again at discharge. Functional recovery was defined as achieving at least 30% improvement on the Barthel Index score from admission compared with the maximum possible room for improvement. RESULTS: Patients who achieved functional recovery (70.3%) were younger and were more likely to be women, live alone, and be without any formal home care before admission, and they had fewer chronic diseases (all P<.01). They also had better cognitive status and a higher Barthel Index score both at admission (mean ± SD, 63.3±18.0 vs 59.6±24.7) and at discharge (mean ± SD, 86.8±10.4 vs 62.2±22.9) (all P<.001). In multivariate analysis, patients <75 years of age (adjusted odds ratio [OR]=1.51; 95% confidence interval [CI], 1.16-1.98; P=.003), women (adjusted OR=1.24; 95% CI, 1.01-1.52; P=.045), patients living alone (adjusted OR=1.61; 95% CI, 1.31-1.98; P<.001), and patients without in-home help prior to admission (adjusted OR=1.39; 95% CI, 1.15-1.69; P=.001) remained at increased odds of functional recovery. In addition, compared with those with moderate-to-severe cognitive impairment (Mini-Mental State Examination score <18), patients with mild-to-moderate impairment (Mini-Mental State Examination score 19-23) and those cognitively intact also had increased odds of functional recovery (adjusted OR=1.56; 95% CI, 1.13-2.15; P=.007; adjusted OR=2.21; 95% CI, 1.67-2.93; P<.001, respectively). CONCLUSIONS: Apart from sociodemographic characteristics, cognition is the strongest factor that identifies older patients more likely to improve during postacute rehabilitation. Further study needs to determine how to best adapt rehabilitation processes to better meet the specific needs of this population and optimize their outcome.