123 research outputs found
Palladium-catalyzed synthesis of mixed anhydrides via carbonylative telomerization
For the first time, mixed carboxylic anhydrides were accessed directly via homogeneous palladium catalysis from 1,3-butadiene and carboxylic acids. Under carbonylative telomerization conditions, the respective mixed 3,8-nonadienoic anhydrides are formed in a single reaction step with yields of up to 82%. These very reactive mixed anhydrides can then be used for consecutive reactions in a one-pot manner and selectively transfer the newly formed unsaturated C9 unit. Possible changes in the proposed mechanism were discussed and in a first example, the mixed anhydrides were utilized to form amides
The Effect of Neutrophil-lymphocyte Ratio on 10-year Survival Outcomes Following Elective Open and EVAR Procedures
Objectives: The neutrophil-lymphocyte ratio (NLR) is a useful and inexpensive inflammatory marker associated with surgical outcomes. This study evaluates the effects of NLR on survival after elective endovascular (EVAR) and open aortic repair (OAR) of abdominal aortic aneurysm.
Methods: We retrospectively reviewed patients from 1989 to 2019 who underwent elective OAR or EVAR at two separate academic centers. Baseline comorbidities were assessed. A receiver operating characteristic (ROC) curve was used to determine a cutoff point where NLR was associated with outcome. Kaplan-Meier survival analysis was used to compare survival through 10-year follow-up.
Results: Overall, 437 patients (mean age, 72.0 6 10.1 years; 74.1% male) underwent 213 EVARs and 224 OARs. Median duration of follow-up was 4.55 years. The analysis of the ROC curve yielded an NLR of 3.94 with the highest specificity and sensitivity for 10-year survival. Baseline characteristics were similar between groups, except for an increased age in the group with NLR \u3e3.94 (73.5 vs 70.9 years; P ¼ .008) (Table). KaplanMeier analysis revealed that patients with NLR \u3e3.94 had decreased 10-year survival (37.2% vs 54.2%; P ¼ .0001) (Fig). By univariate analysis, NLR \u3e3.94 (P ¼ .0001), chronic obstructive pulmonary disease (P ¼ .006), and increased age (P ¼ .0001) were associated with increased mortality. On multivariable cox regression analysis, an NLR \u3e3.94 (odds ratio [OR], 1.69; 95% confidence interval [CI], 1.19-2.40), increased age (OR, 1.05; 95% CI, 1.03-1.07), and chronic obstructive pulmonary disease (OR, 1.44; 95% CI, 1.01-2.07) were associated with increased risk of mortality. Between OAR and EVAR, no difference in late survival was noted (49.9% vs 43.5%; P ¼ .24).
Conclusions: An NLR \u3e3.94 is associated with increased mortality over a 10-year follow-up period after open and endovascular aortic repair. Future studies to further understand the driving force between an elevated NLR and increased mortality are warranted
Specific pathway abundances in the neonatal calf faecal microbiome are associated with susceptibility to Cryptosporidium parvum infection: a metagenomic analysis.
Cryptosporidium parvum is the main cause of calf scour worldwide. With limited therapeutic options and research compared to other Apicomplexa, it is important to understand the parasites' biology and interactions with the host and microbiome in order to develop novel strategies against this infection. The age-dependent nature of symptomatic cryptosporidiosis suggests a link to the undeveloped immune response, the immature intestinal epithelium, and its associated microbiota. This led us to hypothesise that specific features of the early life microbiome could predict calf susceptibility to C. parvum infection. In this study, a single faecal swab sample was collected from each calf within the first week of life in a cohort of 346 animals. All 346 calves were subsequently monitored for clinical signs of cryptosporidiosis, and calves that developed diarrhoea were tested for Rotavirus, Coronavirus, E. coli F5 (K99) and C. parvum by lateral flow test (LFT). A retrospective case–control approach was taken whereby a subset of healthy calves (Control group; n = 33) and calves that went on to develop clinical signs of infectious diarrhoea and test positive for C. parvum infection via LFT (Cryptosporidium-positive group; n = 32) were selected from this cohort, five of which were excluded due to low DNA quality. A metagenomic analysis was conducted on the faecal microbiomes of the control group (n = 30) and the Cryptosporidium-positive group (n = 30) prior to infection, to determine features predictive of cryptosporidiosis. Taxonomic analysis showed no significant differences in alpha diversity, beta diversity, and taxa relative abundance between controls and Cryptosporidium-positive groups. Analysis of functional potential showed pathways related to isoprenoid precursor, haem and purine biosynthesis were significantly higher in abundance in calves that later tested positive for C. parvum (q ≤ 0.25). These pathways are either absent or streamlined in the C. parvum parasites. Though the de novo production of isoprenoid precursors, haem and purines are absent, C. parvum has been shown to encode enzymes that catalyse the downstream reactions of these pathway metabolites, indicating that C. parvum may scavenge those products from an external source. The host has previously been put forward as the source of essential metabolites, but our study suggests that C. parvum may also be able to harness specific metabolic pathways of the microbiota in order to survive and replicate. This finding is important as components of these microbial pathways could be exploited as potential therapeutic targets for the prevention or mitigation of cryptosporidiosis in bovine neonates
Patient–provider perceptions of diabetes and its impact on self-management: a comparison of African-American and White patients
Aims To compare patient–provider differences in diabetes-related perceptions between African-American and White patients and to examine its association with self-care behaviours. Methods One hundred and thirty patient–provider pairs were recruited from the greater Detroit area. Patients and providers completed a survey assessing perceptions about diabetes-related concepts and demographic background. The Diabetes Semantic Differential Scale was used to measure diabetes-related perceptions. Patients also reported the frequency of performing self-care behaviours, including following a healthy eating plan, engaging in physical activity, blood glucose monitoring, and taking medication and/or insulin. Results There were a greater number of patient–provider differences in diabetes-related perceptions for the African-American patients (nine of 18 concepts) compared with the White patients (four of 18 concepts). Stepwise regression analyses found patients’ semantic differential scores to be significantly associated with five self-care behaviours for African-American patients and two self-care behaviours for White patients. Providers’ semantic differential scores emerged as predictors of self-care behaviours for African-American patients, but not for White patients. Conclusions Our findings suggest that compared with White patients, African-Americans differ in a greater number of diabetes-related perceptions than their providers. Patients’ and providers’ perceptions of diabetes care concepts have a significant impact on a greater number of self-care behaviours for African-American patients than White patients. Diabet. Med. 25, 341–348 (2008)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72171/1/j.1464-5491.2007.02371.x.pd
KIF5A and the contribution of susceptibility genotypes as a predictive biomarker for multiple sclerosis
There is increasing interest in the development of multiple sclerosis (MS) biomarkers that reflect central nervous system tissue injury to determine prognosis. We aimed to assess the prognostic value of kinesin superfamily motor protein KIF5A in MS by measuring levels of KIF5A in cerebrospinal fluid (CSF) combined with analysis of single nucleotide polymorphisms (SNPs; rs12368653 and rs703842) located within a MS susceptibility gene locus at chromosome 12q13–14 region. Enzyme-linked immunosorbent assay was used to measure KIF5A in CSF obtained from two independent biobanks comprising non-inflammatory neurological disease controls (NINDC), clinically isolated syndrome (CIS) and MS cases. CSF KIF5A expression was significantly elevated in progressive MS cases compared with NINDCs, CIS and relapsing–remitting MS (RRMS). In addition, levels of KIF5A positively correlated with change in MS disease severity scores (EDSS, MSSS and ARMSSS), in RRMS patients who had documented disease progression at 2-year clinical follow-up. Copies of adenine risk alleles (AG/AA; rs12368653 and rs703842) corresponded with a higher proportion of individuals in relapse at the time of lumbar puncture (LP), higher use of disease-modifying therapies post LP and shorter MS duration. Our study suggests that CSF KIF5A has potential as a predictive biomarker in MS and further studies into the potential prognostic value of analysing MS susceptibility SNPs should be considered
Ethernet-based fronthauling for cloud-radio access networks
Standardization bodies such as IEEE and 3GPP, as well as other interest groups, are in the process of defining and standardizing different functional subdivisions within mobile network base stations, primarily to reduce the data rate requirements imposed on the transport architecture by 4th and 5th generation mobile systems. Ethernet is considered the leading candidate for the transport architecture as it brings benefits from structural and operational convergence in what is now termed the “xhaul” (x signifying front, mid or back). This paper reports on the performance of different functional subdivisions over a bridged Ethernet network and presents some of the main issues that occur when internetworking at the Ethernet transport level. In particular, it examines Priority-based Scheduling within an Ethernet fronthaul, which is also a subject of active standardization by IEEE
Software Defined Networking Opportunities for Intelligent Security Enhancement of Industrial Control Systems
In the last years, cyber security of Industrial Control Systems (ICSs) has become an important issue due to the discovery of sophisticated malware that by attacking Critical Infrastructures, could cause catastrophic safety results. Researches have been developing countermeasures to enhance cyber security for pre-Internet era systems, which are extremely vulnerable to threats. This paper presents the potential opportunities that Software Defined Networking (SDN) provides for the security enhancement of Industrial Control Networks. SDN permits a high level of configuration of a network by the separation of control and data planes. In this work, we describe the affinities between SDN and ICSs and we discuss about implementation strategies
Isotopic exchange processes in cold plasmas of H2/D2 mixtures
12 páginas, 3 tablas, 10 figuras.-Isotope exchange in low pressure cold plasmas of H2/D2 mixtures has been investigated by means of mass spectrometric measurements of neutrals and ions, and kinetic model calculations.
The measurements, which include also electron temperatures and densities, were performed in a stainless steel hollow cathode reactor for three discharge pressures: 1, 2 and 8 Pa, and for mixture
compositions ranging from 100% H2 to 100% D2. The data are analyzed in the light of the model calculations, which are in good global agreement with the experiments. Isotope selective effects are found both in the surface recombination and in the gas-phase ionic chemistry.
The dissociation of the fuel gas molecules is followed by wall recycling, which regenerates H2 and D2 and produces HD. Atomic recombination at the wall is found to proceed through an Eley–Rideal mechanism, with a preference for reaction of the adsorbed atoms with gas phase D atoms. The best fit probabilities for Eley–Rideal abstraction with H and D are:gER H = 1.5 x 10-3, gER D = 2.0 x 10-3. Concerning ions, at 1 Pa the diatomic species H2+,D2+ and HD+, formed directly by electron impact, prevail in the distributions, and at 8 Pa, the triatomic ions H3+, H2D+, HD2+ and D3+, produced primarily in reactions of diatomic ions with molecules, dominate the plasma composition. In this higher pressure regime, the formation of the mixed ions H2D+ and HD2
+ is favoured in comparison with that of H3
+ and D3+, as expected on statistical grounds. The model results predict a very small preference, undetectable within the precision of the measurements, for the generation of triatomic ions with a higher degree of deuteration, which is probably a residual influence at room temperature of the marked zero point energy effects (ZPE), relevant for deuterium fractionation in interstellar space. In contrast,ZPE effects are found to be decisive for the observed distribution of monoatomic ions H+ and D+,
even at room temperature. The final H+/D+ ratio is determined to a great extent by proton (and deuteron) exchange, which favours the enhancement of H+ and the concomitant decrease of D+.This work has been funded by the MICINN of Spain under projects FIS 2007-61686, FIS2010-16455 and CSD2009-00038.
EC acknowledges also funding from the JdC program of the MICINN.Peer reviewe
Real-time time-domain fluorescence lifetime imaging including single-shot acquisition with a segmented optical image intensifier
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