845 research outputs found
Proportional-integral-plus control applications of state-dependent parameter models
This paper considers proportional-integral-plus (PIP) control of non-linear systems defined by state-dependent parameter models, with particular emphasis on three practical demonstrators: a microclimate test chamber, a 1/5th-scale laboratory representation of an intelligent excavator, and a full-scale (commercial) vibrolance system used for ground improvement on a construction site. In each case, the system is represented using a quasi-linear state-dependent parameter (SDP) model structure, in which the parameters are functionally dependent on other variables in the system. The approach yields novel SDP-PIP control algorithms with improved performance and robustness in comparison with conventional linear PIP control. In particular, the new approach better handles the large disturbances and other non-linearities typical in the application areas considered
Ex vivo perfusion, arteriography, and autotransplantation procedures for kidney salvage
Three kidneys with arterial lesions that would have been difficult or impossible to repair by standard vascular reconstruction were removed, perfused by the Belzer technique, and returned to host after partial or complete autotransplantation. The fact that kidneys can be studied, dissected, repaired, and constantly salvaged with this technique should have important implications in several aspects of urologic operations
THE EFFECTS OF FIELD EMITTED ELECTRONS ON RF SURFACE
The ever-growing demand for higher RF gradients has
considerably increased the risk of breakdown in
accelerating structures. Field emission is the most
common form of RF breakdown that generates free
electrons capable of inflicting irreversible damages on the
RF surface. This paper presents a systematic experimental
and simulation programme to understand possible sources
and their influence on RF cavity operatio
Arteriography during ex vivo renal perfusion A complication
A case of bilateral renal-cell carcinoma unsuccessfully treated with bench surgery is reported. The reason for failure was apparently the toxicity of the contrast media used during the ex vivo arteriographic studies. Š 1973
Analysing multi-person timing in music and movement : event based methods
Accurate timing of movement in the hundreds of milliseconds range is a hallmark of human activities such as music and dance. Its study requires accurate measurement of the times of events (often called responses) based on the movement or acoustic record. This chapter provides a comprehensive over - view of methods developed to capture, process, analyse, and model individual and group timing [...] This chapter is structured in five main sections, as follows. We start with a review of data capture methods, working, in turn, through a low cost system to research simple tapping, complex movements, use of video, inertial measurement units, and dedicated sensorimotor synchronisation software. This is followed by a section on music performance, which includes topics on the selection of music materials, sound recording, and system latency. The identification of events in the data stream can be challenging and this topic is treated in the next section, first for movement then for music. Finally, we cover methods of analysis, including alignment of the channels, computation of between channel asynchrony errors and modelling of the data set
Investigating the prevalence, predictors, and prognosis of suboptimal statin use early after a non-ST elevation acute coronary syndrome
BACKGROUND:High-potency statin therapy is recommended in the secondary prevention of car-diovascular disease but discontinuation, dose reduction, statin switching, and/or nonadherence occurin practice.OBJECTIVES:To determine the prevalence and predictors of deviation from high-potency statin useearly after a non-ST elevation acute coronary syndrome (NSTE-ACS) and its association with subse-quent major adverse cardiovascular events (MACE) and all-cause mortality (ACM).METHODS:A total of 1005 patients from a UK-based prospective NSTE-ACS cohort study dis-charged on high-potency statin therapy (atorvastatin 80 mg, rosuvastatin 20 mg, or 40 mg daily)were included. At 1 month, patients were divided into constant high-potency statin users, and subop-timal users incorporating statin discontinuation, dose reduction, switching statin to a lower equivalentpotency, and/or statin nonadherence. Follow-up was a median of 16 months.RESULTS:There were 156 suboptimal (w15.5%) and 849 constant statin users. Factors associatedin multivariable analysis with suboptimal statin occurrence included female sex (odds ratio 1.75, 95%confidence interval [CI] 1.14â2.68) and muscular symptoms (odds ratio 4.28, 95% CI 1.30â14.08).Suboptimal statin use was associated with increased adjusted risks of time to MACE (hazard ratio2.10, 95% CI 1.25â3.53,P5.005) and ACM (hazard ratio 2.46, 95% CI 1.38â4.39,P5.003). Sub-group analysis confirmed that the increased MACE/ACM risks were principally attributable to statindiscontinuation or nonadherence.CONCLUSIONS:Conversion to suboptimal statin use is common early after NSTE-ACS and ispartly related to muscular symptoms. Statin discontinuation or non-adherence carries an adverse prog-nosis. Interventions that preserve and enhance statin utilization could improve post NSTE-ACSoutcomes
Confidence College â an online education tool for neurology patients
COVID-19 and its aftermath highlight the importance of patient self-care and involvement in monitoring and improving their health. Resources to guide this are essential. Our objective was to create a web-based patient education tool, to facilitate patient education and empowerment for people with epilepsy, multiple sclerosis and Parkinsonâs disease, available without cost to patients, carers and clinicians. This project was conducted within community and secondary neurology services. Patients and their carers were involved in designing, reviewing and revising the tool, as equal partners with clinicians and digital engineers. A web-based design template was developed with graphics and links to enable patients to create personalised plans. Participants are patients, carers, clinicians (neurology consultants and specialist nurses), neurological charities, the London Neuroscience Clinical Network, NHS England and Shift.ms (a service design team with experience in creating digital services for individuals living with neurological conditions). Shift.ms conducted in-depth interviews. Clinicians used evidence from personal and PubMed databases. Shift.ms analysed and co-ordinated the responses, and designed the pilot tool. Confidence College provides a delivery model for patient education relating to multiple sclerosis, epilepsy and Parkinsonâs disease. It requires follow-up evaluation regarding uptake. This web-based accessible patient empowerment tool has no limit on recurrent use, low maintenance costs and no additional costs in up-scaling the number of users. It is ideally suited for use during and after the COVID-19 pandemic
The effect of a dominant kinase-dead Csf1r mutation associated with adult-onset leukoencephalopathy on brain development and neuropathology
Amino acid substitutions in the kinase domain of the human CSF1R protein are associated with autosomal dominant adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP). To model the human disease, we created a disease-associated mutation (Glu631Lys; E631K) in the mouse Csf1r locus. Previous analysis demonstrated that heterozygous mutation (Csf1rE631K/+) had a dominant inhibitory effect on CSF1R signaling in vitro and in vivo but did not recapitulate the pathology of the human disease. We speculated that leukoencephalopathy in humans requires an environmental trigger and/or epistatic interaction with common neurodegenerative disease-associated alleles. Here we examine the impact of heterozygous Csf1r mutation on microglial phenotype, normal postnatal brain development, age-related changes in gene expression and on two distinct pathologies in which microgliosis is a prominent feature, prion disease and experimental autoimmune encephalitis (EAE). The heterozygous Csf1rE631K/+ mutation reduced microglial abundance and the expression of microglial-associated transcripts relative to wild-type controls at 12 weeks and 43 weeks of age but had no selective effect on homeostatic markers such as P2ry12. An epistatic interaction was demonstrated between Csf1rE631K/+ and Cxc3r1EGFP/+ genotypes leading to dysregulated microglial and neuronal gene expression in both hippocampus and striatum. Heterozygous Csf1rE631K mutation reduced the microgliosis associated with both diseases. There was no significant impact on disease severity or progression in prion disease. In EAE, induced expression of inflammation-associated transcripts in the hippocampus and striatum was suppressed in parallel with microglia-specific transcripts, but spinal cord demyelination was exacerbated. The results support a dominant-negative model of CSF1R-associated leukoencephalopathy and likely contributions of an environmental trigger and/or genetic background to neuropathology
Sinteza 2-(1H-indol-3-il)acetil-N-(supstituiranih fenil)hidrazinkarbotioamida i srodnih heterocikliÄkih spojeva te procjena njihovog antikonvulzivnog djelovanja i toksiÄnosti
A series of new 5-(1H-indol-3-yl)methyl-4-(substituted aryl)-2,4-dihydro-3H-1,2,4-triazole-3-thiones (4a-g), 5-(1H-indol-3-yl)methyl-N-(substituted aryl)-1,3,4-oxadiazol-2-amines (5a-g) and 5-(1H-indol-3-yl)methyl-N-(substituted aryl)-1,3,4-thiadiazol-2-amines (6a-g) were prepared by treating 2-(1H-indol-3-yl)acetyl-N-(substituted phenyl)hydrazine carbothioamides (3a-g) with suitable reagents. All the newly synthesized compounds were screened for their anticonvulsant activity in the MES model and were compared with the standard drugs phenytoin sodium and carbamazepine. Out of the twenty-one compounds studied, 4b, 4e, 4f, 5b, 5d, 5g, 6b, 6d and 6e showed comparable MES activity to phenytoin and carbamazepine after 0.5 h. Compound 5b showed to be more potent than carbamazepine after 4 h. Compounds 4a, 4c, 4d, 5a, 5c, 5e, 5f, 6f and 6g showed lower neurotoxicity than phenytoin.Reakcijom 2-(1H-indol-3-il)acetil-N-(supstituiranih fenil)hidrazinkarbotioamida (3a-g) s odgovarajuÄim reaktantom sintetizirana je serija novih 5-(1H-indol-3-il)metil-4-(supstituiranih aril)-2,4-dihidro-3H-1,2,4-triazol-3-tiona (4a-g), 5-(1H-indol-3-yl)metil-N-(supstituiranih aril)-1,3,4-oksadiazol-2-amina (5a-g) i 5-(1H-indol-3-il)metil-N-(supstituiranih aril)-1,3,4-tiadiazol-2-amina (6a-g). Ispitano je antikonvulzivno djelovanje sintetiziranih spojeva na MES modelu i usporeÄeno s djelovanjem fenitoin natrija i karbamazepina. Spojevi 4b, 4e, 4f, 5b, 5d, 5g, 6b, 6d i 6e pokazali su MES djelovanje usporedivo s djelovanjem fenitoina i karbamazepina nakon 0,5 h, dok je spoj 5b nakon 4 sata imao snaĹžnije djelovanje od karbamazepina. Osim toga, spojevi 4a, 4c, 4d, 5a, 5c, 5e, 5f, 6f i 6g su manje neurotoksiÄni od fenitoina
Defining the Structural Parameters That Confer Anticonvulsant Activity by the Site-by-Site Modification of ( R )- N â˛-Benzyl 2-Amino-3-methylbutanamide
Primary Amino Acid Derivatives (PAADs) (Nâ˛-benzyl 2-substituted 2-amino acetamides) are structurally related to Functionalized Amino Acids (FAAs) (Nâ˛-benzyl 2- substituted 2-acetamido acetamides) but differ by the absence of the terminal N-acetyl group. Both classes exhibit potent anticonvulsant activities in the maximal electroshock seizure animal model and the reported structure-activity relationships (SARs) of PAADs and FAAs differ in significant ways. Recently, we documented that PAAD efficacy was associated with a hydrocarbon moiety at the C(2)-carbon, while in the FAAs, a substituted heteroatom one atom removed from the C(2)-center was optimal. Previously in this issue, we showed that PAAD activity was dependent upon the electronic properties of the 4â˛-Nâ˛-benzylamide substituent, while FAA activity was insensitive to electronic changes at this site. In this study, we prepared analogs of (R)-Nâ˛-benzyl 2-amino-3-methylbutanamide to identify the structural components for maximal anticonvulsant activity. We demonstrated that the SAR of PAADs and FAAs diverged at the terminal amide site and that PAADs had considerably more structural latitude in the types of units that could be incorporated at this position, suggesting that these compounds function according to different mechanism(s)
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