Sedation with alfentanil and propofol for rhizotomies

Background: Patient safety during sedation for closed rhizotomies is improved when analgesia is optimised, rather than relying on deep sedation for patient comfort. This retrospective study determined the appropriate effect-site concentration (Ce) for alfentanil, in combination with a constant propofol infusion, for optimal pain control during sedation for closed rhizotomies. Airway maintenance is ensured by keeping patients responsive to verbal commands, albeit at the price of inevitable ventilatory depression.Method: The records of patients who received rhizotomies over a six-month period were studied retrospectively. Sixty-three outpatients were included. Patients rated the level of analgesia with each needle placement. If the Ce for alfentanil was adequate, it was kept constant. Otherwise, it was increased in 5 ng/ml increments with each needle placement until analgesia was effective, or up to the maximum Ce for alfentanil of 100 ng/ml. Propofol infusion at a constant Ce of 200 ng/ml was added.Results: Forty-eight per cent of patients reported being comfortable at a Ce for alfentanil of 70–75 ng/ml. Only 5% of patients requested the maximum Ce for alfentanil of 100 ng/ml. All of the patients experienced ventilatory depression, but a patent airway was maintained. The haemodynamic observations were within normal limits. According to the ward records, 16% of the patients complained of nausea, and there was one incident of vomiting.Conclusion: Combining alfentanil at a Ce for alfentanil of 70–100 ng/ml with propofol at 200 ng/ml is a safe and effective method for analgesia during sedation for closed rhizotomies.Keywords: alfentanil, analgesia, procedural sedation, propofol, rhizotomy, target-controlled infusio

Consensus statement: Management of drug-induced liver injury in HIV-positive patients treated for TB

Drug-induced liver injury (DILI) in HIV/tuberculosis (TB) co-infected patients is a common problem in the South African setting, and re-introduction of anti-TB drugs can be challenging for the healthcare worker. Although international guidelines on the re-introduction of TB treatment are available, the definition of DILI is not uniform, management of antiretroviral therapy (ART) in HIV co-infection is not mentioned, and the guidance on management is not uniform and lacks a practical approach. In this consensus statement, we summarise important aspects of DILI and provide practical guidance for healthcare workers for different patient groups and healthcare settings on the re-introduction of anti-TB drugs and ART in HIV/TB co-infected individuals presenting with DILI

Fischer mono- and biscarbene complexes of tungsten with mono- and dimeric heteroaromatic substituents

An electrochemical study of a series of mono- and biscarbene complexes of tungsten pentacarbonyl with mono- and dimeric heteroarene substituents are reported and compared in CH3CN and DCM. Results revealed that the order of oxidation (reduction) depends largely on the aryl substituent attached to the carbene carbon (2-thienyl, 2-furyl or 2-(N-methylpyrrolyl)). The order of oxidation (reduction) for monocarbene complexes containing a monomeric heteroarene substituent ((1)–(3)), a dimeric heteroarene substituent ((4)–(6)) or biscarbene complexes connected with a heteroarene substituent ((7)–(9)) is the same, namely 2-thienyl > 2-furyl > 2-(N-methylpyrrolyl). Carbene complexes containing a larger conjugated heteroarene substituent attached to the carbene carbon reduce more easily than the monomeric analogues. Tungsten biscarbene complexes exhibit two separate oxidation potentials for the two metal centres or one large oxidation peak, consistent with the simultaneous oxidation of the two W metal centres.Norwegian Supercomputing Program (NOTUR) through a grant of computer time (Grant No. NN4654K), the South African National Research Foundation, the Central Research Fund of the University of the Free State, Bloemfontein and the University of Pretoria.http://www.elsevier.com/locate/jelechem2016-02-28hb201

Nutritional status of renal transplant patients

Objective. To assess the effect of renal transplantation on the nutritional status of patients.Design. Prospective descriptive study.Setting. Renal Transplant Clinic at Tygerberg Hospital, Western Cape.Subjects. Fifty-eight renal transplant patients from Tygerberg Hospital were enrolled in the study. The sample was divided into two groups of 29 patients each: group 1, less than 28 months post-transplant; and group 2, more than 28 months post-transplant.Outcome measures. Nutritional status assessment comprised biochemical evaluation, a dietary history, anthropometric measurements and a clinical examination.Results. Serum vitamin B6 levels were below normal in 56% of patients from group 1 and 59% from group 2. Vitamin B6 intake, however, was insufficient in only 14% of patients from group 1and10% from group 2. Serum vitamin C levels were below normal in 7% of patients from group 1 and 24% from group 2, while vitamin C intake was insufficient in 21%and14% of patients from groups 1 and 2 respectively. Serum magnesium levels were below normal in 55% of patients from group 1, and in 28% from group 2. Serum albumin and cholesterol levels increased significantly during the post-transplant period in the total sample (P = 0.0001). There was also a significant increase in body mass index (P = 0.0001) during the post-transplant period.Conclusions. Several nutritional abnormalities were observed, which primarily reflect the side-effects of immunosuppressive therapy. The causes, consequences and treatment of the vitamin B6 and vitamin C deficiencies in renal transplant recipients need further investigation

Electrochemical behaviour and structure of novel phosphine- and phosphite-substituted tungsten(0) Fischer carbene complexes

tThe electrochemical behaviour of a series of sixteen novel Fischer ethoxy- and aminocarbenecomplexes of the type [(CO)4(PPh3)W = C(X)R] with R = 2-thienyl or 2-furyl and X = OEt or NHCy,(1-4), [(CO)3(dppe)W = C(X)R] with R = 2-thienyl or 2-furyl and X = OEt or NHCy, (5-8) (dppe = 1,2-bis(diphenylphosphino)ethane) and [(CO)4P(OPh)3W = C(X)R] with R = 2-thienyl or 2-furyl and X = OEtor NHCy, (9-12) is investigated by means of cyclic voltammetry. The complexes all exhibit a two-electronoxidation process that is W-based and a one-electron reduction that is mainly localized on the carbeneligand. Complexes 1-4 and 9-12 are considerably more difficult to oxidize than 5-8 due to the better -acceptor ability of the (CO)4(PR 3) (R = Ph or OPh) ligand combination than that of (CO)3(dppe). Den-sity functional theory calculations on the neutral, reduced and oxidized complexes confirmed the role ofthe frontier orbitals in the oxidation and reduction processes and enabled formulation of mathematicalrelationships that can be used to predict experimental measured potentials. X-ray crystal structures of2cis, 3 and 5 are discussed.http://www.elsevier.com/locate/electactahb201

A surrogate model for the economic evaluation of renewable hydrogen production from biomass feedstocks via supercritical water gasification

Supercritical water gasification is a promising technology for renewable hydrogen production from high moisture content biomass. This work produces a machine learning surrogate model to predict the Levelised Cost of Hydrogen over a range of biomass compositions, processing capacities, and geographic locations. The model is published to facilitate early-stage economic analysis (doi.org/10.6084/m9.figshare.22811066). A process simulation using the Gibbs reactor provided the training data using 40 biomass compositions, five processing capacities (10–200 m3/h), and three geographic locations (China, Brazil, UK). The levelised costs ranged between 3.81 and 18.72 $/kgH2 across the considered parameter combinations. Heat and electricity integration resulted in low process emissions averaging 0.46 kgCO2eq/GJH2 (China and Brazil), and 0.37 kgCO2eq/GJH2 (UK). Artificial neural networks were most accurate when compared to random forests and support vector regression for the surrogate model during cross-validation, achieving an accuracy of MAPE: 0.99 on the test set

Measurement of the magnitude of force applied by students when learning a mobilisation technique

Passive accessory intervertebral movements (PAIVM’s) are frequently used by physiotherapists in the  assessment and management of patients. Studies investigating the reliability of passive mobilisation techniques have shown conflicting results. Therefore, standardisation of PAIVM’s is essential for research and teaching purposes, which could result in better clinical management. In order to standardise graded passive mobilisation techniques, a reliable, easy-to-use, objective measurement tool must be used. The aim of this  study was to determine whether it is necessary to quantify the magnitude of force applied when teaching a grade I central  posteroanterior (PA) mobilisation technique (according to Maitland) on the cervical spine. An objective measurement tool (FlexiForceTM) was used to determine the consistency of force applied by third and fourth year physiotherapy students while performing this technique. Twenty third- and 20 fourth year physiotherapy students (n=40) were randomly selected. Each subject performed a grade I central PA on sensors placed on C6 for 25 seconds. The average maximum grade 1 force applied by the third year students was  significantly higher than the force applied by the fourth year students (p=0.034). There was a significantly larger variation in applied force among third years (p=0.00043). The results indicate that the current teaching method is insufficient to ensure inter-therapist reliability amongst students, emphasising the need for an objective measurement tool to be used for teaching students. The measurement tool used in this study is economical, easily applied and is an efficient method of measuring the magnitude of force. Further research is needed to demonstrate the reliability and validity of the tool to assist teaching and research in a clinical setting

The Category of Node-and-Choice Forms, with Subcategories for Choice-Sequence Forms and Choice-Set Forms

The literature specifies extensive-form games in many styles, and eventually I hope to formally translate games across those styles. Toward that end, this paper defines $\mathbf{NCF}$, the category of node-and-choice forms. The category's objects are extensive forms in essentially any style, and the category's isomorphisms are made to accord with the literature's small handful of ad hoc style equivalences. Further, this paper develops two full subcategories: $\mathbf{CsqF}$ for forms whose nodes are choice-sequences, and $\mathbf{CsetF}$ for forms whose nodes are choice-sets. I show that $\mathbf{NCF}$ is "isomorphically enclosed" in $\mathbf{CsqF}$ in the sense that each $\mathbf{NCF}$ form is isomorphic to a $\mathbf{CsqF}$ form. Similarly, I show that $\mathbf{CsqF_{\tilde a}}$ is isomorphically enclosed in $\mathbf{CsetF}$ in the sense that each $\mathbf{CsqF}$ form with no-absentmindedness is isomorphic to a $\mathbf{CsetF}$ form. The converses are found to be almost immediate, and the resulting equivalences unify and simplify two ad hoc style equivalences in Kline and Luckraz 2016 and Streufert 2019. Aside from the larger agenda, this paper already makes three practical contributions. Style equivalences are made easier to derive by [1] a natural concept of isomorphic invariance and [2] the composability of isomorphic enclosures. In addition, [3] some new consequences of equivalence are systematically deduced.Comment: 43 pages, 9 figure

Mechanism of virus attenuation by codon pair deoptimization

Codon pair deoptimization is an efficient virus attenuation strategy, but the mechanism that leads to attenuation is unknown. The strategy involves synthetic recoding of viral genomes that alters the positions of synonymous codons, thereby increasing the number of suboptimal codon pairs and CpG dinucleotides in recoded genomes. Here we identify the molecular mechanism of codon pair deoptimization-based attenuation by studying recoded influenza A viruses. We show that suboptimal codon pairs cause attenuation, whereas the increase of CpG dinucleotides has no effect. Furthermore, we show that suboptimal codon pairs reduce both mRNA stability and translation efficiency of codon pair-deoptimized genes. Consequently, reduced protein production directly causes virus attenuation. Our study provides evidence that suboptimal codon pairs are major determinants of mRNA stability. Additionally, it demonstrates that codon pair bias can be used to increase mRNA stability and protein production of synthetic genes in many areas of biotechnology

Do experienced physiotherapists apply equal magnitude of force during a grade I central pa on the cervical spine?

Background and purpose: Physiotherapists frequently use central posterior-anterior (PA) joint mobilization techniques for assessing and managing spinal disorders. Manual examination findings provide the basis for the selection of treatment techniques. From the literature it is evident that the level of reliability varies when physiotherapists perform different mobilization techniques. Repeatability of mobilization techniques is important for better physiotherapy management. The aim of the study was to determine whether experienced physiotherapists apply equal magnitude of force during a grade I central PA mobilisation technique on the cervical spine. Another aim was to determine the variation in the magnitude of force applied by each individual physiotherapist. Subjects: Sample of convenience, consisting of sixteen (n=16) selected qualified physiotherapists with experience in Orthopaedic Manual Therapy. Methods: A grade I central PA was performed on the Flexiforce TM sensors positioned on C6 of the same asymptomatic model to measure the applied magnitude of force. Two separate measurements, each lasting 30-seconds, were obtained. Results: The average maximum peak force applied by the majority of physiotherapists (87.5%) was between 10.95g and 72g. The difference in the forces applied for the two measurements ranged between 0.64g and 24.4g. The Bland Altman scatterplot determined the mean of the difference between measurement one and two, calculated for the group, was zero. When comparing the two measurements, little variation was noted in the forces applied, as well as the coefficient of variation for each physiotherapist. Conclusion and Discussion: Current results demonstrated good intra-therapist and moderate to good inter-therapist repeatability. Further research is required to generalize results