Isoaccepting Lysine Transfer Ribonucleic Acid Species of Pseudomonas Aeruginosa

Pseudomonas aeruginosa tRNA was treated with iodine, CNBr and N-ethylmaleimide,three thionucleotide-specific reagents. Reaction with iodine resulted in extensive loss of acceptor activity by lysine tRNA, glutamic acid tRNA, glutamine tRNA, serine tRNA and tyrosine tRNA. CNBr treatment resulted in high loss of acceptor ability by lysine tRNA, glutamic acid tRNA and glutamine tRNA. Only the acceptor ability of tyrosine tRNA was inhibited up to 66% by N-ethylmaleimide treatment, a reagent specific for 4-thiouridine. By the combined use of benzoylated DEAE-cellulose and DEAESephadex columns, lysine tRNA of Ps. aeruginosa was resolved into two isoaccepting species, a major, tRNAL'y and a minor, tRNA'Ys. Co-chromatography of 14C-labelled tRNALYS and 3H-labelled tRNALy, on benzoylated DEAE-cellulose at pH4.5 gave two distinct, non-superimposable profiles for the two activity peaks, suggesting that they were separate species. The acceptor activity of these two species was inhibited by about 95% by iodine and CNBr. Both the species showed equal response to codons AAA and AAG and also for poly(A) and poly(A1,Gl) suggesting that the anticodon of these species was UUU. Chemical modification of these two species by iodine did not inhibit the coding response. The two species of lysine of Ps. aeruginosa are truly redundant in that they are indistinguishable either by chemical modification or by their coding response.

Patient perspectives of factors contributing to inadequate dietary intake in acute care patients in hospital

Up to 30% of acute care patients consume less than half of the food provided in hospital. Inadequate dietary intake can have adverse clinical outcomes, including a higher risk of in-hospital mortality. This study aimed to investigate the reasons for poor intake among acute care patients in hospital. Patients with an observed intake of ≤50% of the food provided at lunch were approached to participate in the study. Thirty-two patients participated in semi-structured interviews over a three week period, to provide their perspective of food and mealtimes in hospital and discuss the reasons and factors influencing inadequate intake. Responses were coded and analysed thematically using the framework method. Patients reported both individual and organisational factors contribute to their inadequate intake. Half the patients reported the size of the meals were too large, with some patients reporting that large meal sizes puts them off their food and reduced their intake. ‘Not important to eat all the food provided’, and ‘do not need to eat much food in hospital’ were common attitudes among the patients. Half the patients reported that nurses did not observe their intake and were not concerned if all the food was not eaten. Identifying the reasons for poor intake can assist with the development of suitable interventions to improve dietary intake and reduce the risk of adverse clinical outcomes. Further investigation of suitable interventions to reduce portion sizes and improve both staff and patient perceptions of the importance of food in hospital is recommended.

Charge transfer in Chevrel phases

Chemical shifts of Mo K-absorption edge and Mo core level binding energies in Ax Mo6 Ch8 (Ch = S, Se, Te) Chevrel phases show clear evidence for charge transfer from the A element to the Mo6 cluster. The chemical shifts vary linearly with the intercluster Mo-Mo distance as well as the rhombohedral parameter.

Superhydrophobic fabrics for oil-water separation based on the metal organic charge transfer complex CuTCNAQ

This work reports on the fabrication of a superhydrophobic nylon textile based on the organic charge transfer complex CuTCNAQ (TCNAQ = 11,11,12,12-tetracyanoanthraquinodimethane). The nylon fabric that is metallized with copper undergoes a spontaneous chemical reaction with TCNAQ dissolved in acetonitrile to form nanorods of CuTCNAQ that are intertwined over the entire surface of the fabric. This creates the necessary micro and nanoscale roughness that is required for the Cassie-Baxter state thereby achieving a superhydrophobic/superoleophilic surface without the need for a fluorinated surface. The material is characterised with SEM, FT-IR and XPS spectroscopy and investigated for its ability to separate oil and water in two modes, namely under gravity and as an absorbent. It is found that the fabric can separate dichloromethane, olive oil and crude oil from water and in fact reduce the water content of the oil during the separation process. The fabric is reusable and tolerant to conditions such as seawater, hydrochloric acid and extensive time periods on the shelf. Given that CuTCNAQ is a copper based semiconductor may also open up the possibility of other applications in areas such as photocatalysis and antibacterial applications.

Mass transfer with surface reaction in arrays of cylinders at low reynolds and high peclet numbers

Creeping flow hydrodynamics combined with diffusion boundary layer equation are solved in conjunction with free-surface cell model to obtain a solution of the problem of convective transfer with surface reaction for flow parallel to an array of cylindrical pellets at high Peclet numbers and under fast and intermediate kinetics regimes. Expressions are derived for surface concentration, boundary layer thickness, mass flux and Sherwood number in terms of Damkoehler number, Peclet number and void fraction of the array. The theoretical results are evaluated numerically.

Prevention of foot ulcers in the at-risk patient with diabetes: A systematic review

Background Prevention of foot ulcers in patients with diabetes is extremely important to help reduce the enormous burden of foot ulceration on both patient and health resources. A comprehensive analysis of reported interventions is not currently available, but is needed to better inform caregivers about effective prevention. The aim of this systematic review is to investigate the effectiveness of interventions to prevent first and recurrent foot ulcers in persons with diabetes who are at risk for ulceration. Methods The available medical scientific literature in PubMed, EMBASE, CINAHL and the Cochrane database was searched for original research studies on preventative interventions. Both controlled and non-controlled studies were selected. Data from controlled studies were assessed for methodological quality by two independent reviewers. Results From the identified records, a total of 30 controlled studies (of which 19 RCTs) and another 44 non-controlled studies were assessed and described. Few controlled studies, of generally low to moderate quality, were identified on the prevention of a first foot ulcer. For the prevention of recurrent plantar foot ulcers, multiple RCTs with low risk of bias show the benefit for the use of daily foot skin temperature measurements and consequent preventative actions, as well as for therapeutic footwear that demonstrates to relieve plantar pressure and that is worn by the patient. To prevent recurrence, some evidence exists for integrated foot care when it includes a combination of professional foot treatment, therapeutic footwear and patient education; for just a single session of patient education, no evidence exists. Surgical interventions can be effective in selected patients, but the evidence base is small. Conclusion The evidence base to support the use of specific self-management and footwear interventions for the prevention of recurrent plantar foot ulcers is quite strong, but is small for the use of other, sometimes widely applied, interventions and is practically nonexistent for the prevention of a first foot ulcer and non-plantar foot ulcer.

Application of the Conjugate Gradient Method to a Problem on Minimum Time Orbit Transfer

This correspondence considers the problem of optimally controlling the thrust steering angle of an ion-propelled spaceship so as to effect a minimum time coplanar orbit transfer from the mean orbital distance of Earth to mean Martian and Venusian orbital distances. This problem has been modelled as a free terminal time-optimal control problem with unbounded control variable and with state variable equality constraints at the final time. The problem has been solved by the penalty function approach, using the conjugate gradient algorithm. In general, the optimal solution shows a significant departure from earlier work. In particular, the optimal control in the case of Earth-Mars orbit transfer, during the initial phase of the spaceship's flight, is found to be negative, resulting in the motion of the spaceship within the Earth's orbit for a significant fraction of the total optimized orbit transfer time. Such a feature exhibited by the optimal solution has not been reported at all by earlier investigators of this problem.

Separation of sulfur-containing components of transfer ribonucleic acid on Bio-Gel P-2 and Sephadex G-10 columns

S-Labeled nucleosides of E. coli tRNA and some of the derivatives of thionucleosides were separated on Bio-Gel P-2 and Sephadex G-10 columns employing buffers of low salt concentration and high pH.

Laminar compressible boundary layers with vectored mass transfer

The paper studies the influence of vectored suction or injection on the flow and heat transfer at the stagnation point of a two-dimensional body (a cylinder) and an axisymmetric body (a sphere) with allowance for the effects of variable gas properties. The analysis is based on the boundary-layer equations in dimensionless form for the steady compressible fluid with variable properties in the stagnation region of a two-dimensional or an axisymmetric body with tangential and normal surface mass transfer under similarity requirements. It is shown that the variation of the density-viscosity product across the boundary layer has a strong effect on the skin friction and heat transfer. This gives rise to a point of inflection which can be removed by suction and by increasing the wall temperature. The skin friction and heat transfer are significantly affected by the pressure gradient parameter.

Two forms of methionyl-transfer RNA synthetase from Mycobacterium Smegmatis

Two methionyl-transfer RNA synthetases (A and B forms) have been isolated from Image . The homogeneous preparations of the enzymes showed 1500 fold increase in specific activity in aminoacylation of methionine specific tRNA. The A and B forms differed in their specificity of aminoacylation of tRNAmMet and tRNAfMet; enzyme B exhibited much higher specificity for tRNAfMet. The molecular activities of A and B enzymes for aminoacid and tRNA were identical. The turnover number for aminoacid was 27 fold greater than that for tRNA, while the Km values for tRNA were lower by a factor of 106 as compared to the aminoacid. Both the enzymes catalysed ATP-pyrophosphate exchange reaction to the same extent.

Velocity ratio-cum-transfer matrix method for the evaluation of a muffler with mean flow

The paper deals with a method for the evaluation of exhaust muffers with mean flow. A new set of variables, convective pressure and convective mass velocity, have been defined to replace the acoustic variables. An expression for attenuation (insertion loss) of a muffler has been proposed in terms of convective terminal impedances and a velocity ratio, on the lines of the one existing for acoustic filters. In order to evaluate the velocity ratio in terms of convective variables, transfer matrices for various muffler elements have been derived from the basic relations of energy, mass and momentum. Finally, the velocity ratiocum-transfer matrix method is illustrated for a typical straight-through muffler.

On the transfer matrix for a uniform tube with a moving medium

Abstract is not available.

Numerical study of heat transfer in laminar film boiling by the finite-difference method

The finite-difference form of the basic conservation equations in laminar film boiling have been solved by the false-transient method. By a judicious choice of the coordinate system the vapour-liquid interface is fitted to the grid system. Central differencing is used for diffusion terms, upwind differencing for convection terms, and explicit differencing for transient terms. Since an explicit method is used the time step used in the false-transient method is constrained by numerical instability. In the present problem the limits on the time step are imposed by conditions in the vapour region. On the other hand the rate of convergence of finite-difference equations is dependent on the conditions in the liquid region. The rate of convergence was accelerated by using the over-relaxation technique in the liquid region. The results obtained compare well with previous work and experimental data available in the literature.

Laminar hypersonic boundary-layer flow at a three-dimensional stagnation point with slip and mass transfer

Abstract is not available.