A prospective study on antibiotic prescribing pattern among in-patients of medicine department of a tertiary care hospital

Background: Irrational prescription is a major contributor to the antimicrobial resistance. Tertiary care centres in a state are the centres of excellence where policies are framed. So, they have an important role in promoting rational antibiotic prescription.Methods: The study was conducted on in-patients of medicine ward in government medical college, Calicut, for a period of 2 months (January to February 2018), The data was collected from IP case records of patients. The parameters checked includes appropriateness of the antibiotic as, to whether it is according to our hospital antibiotic policy, whether de-escalation and change to oral drug was done, whether it is prescribed by generic name, is it given as fixed drug combination (FDC), is it from national list of essential medicine.Results: Among the 135-prescription analyzed, total 225 antibiotics were used. Cephalosporins (32%) were the most commonly used. Of this only 40% was given by generic prescription. 27% was FDCs. 55% was from national list of essential medicines and 69% of them were ‘WATCH’ drug according to WHO Antibiotic Policy. Regarding appropriateness of prescriptions around 56% included right drug, 93% had right dose and frequency, and 70% had right duration and 100% were given through right route.Conclusions: Strict adherence to hospital antibiotic policy and plan for effective teaching programs regarding antibiotic resistance and importance of rational prescription of antibiotics can improve the quality of antibiotic prescription and minimize antibiotic resistance

Selection of tRNA Charging Quality Control Mechanisms That Increase Mistranslation of the Genetic Code

Mistranslation can follow two events during protein synthesis: production of non-cognate amino acid:transfer RNA (tRNA) pairs by aminoacyl-tRNA synthetases (aaRSs) and inaccurate selection of aminoacyl-tRNAs by the ribosome. Many aaRSs actively edit non-cognate amino acids, but editing mechanisms are not evolutionarily conserved, and their physiological significance remains unclear. To address the connection between aaRSs and mistranslation, the evolutionary divergence of tyrosine editing by phenylalanyl-tRNA synthetase (PheRS) was used as a model. Certain PheRSs are naturally error prone, most notably a Mycoplasma example that displayed a low level of specificity consistent with elevated mistranslation of the proteome. Mycoplasma PheRS was found to lack canonical editing activity, relying instead on discrimination against the non-cognate amino acid by kinetic proofreading. This mechanism of discrimination is inadequate for organisms where translation is more accurate, as Mycoplasma PheRS failed to support Escherichia coli growth. However, minor changes in the defunct editing domain of the Mycoplasma enzyme were sufficient to restore E. coli growth, indicating that translational accuracy is an evolutionarily selectable trait

DFT Benchmark Studies on Representative Species and Poisons of Methane Steam Reforming on Ni(111)

Ni catalysts used in Methane Steam Reforming (MSR) are highly susceptible to poisoning by carbon-based species, which poses a major impediment to the productivity of industrial operations. These graphitic carbon-like formations are typically modelled from first principles as graphene. Although numerous experimental investigations have been carried out, a conclusive mechanistic molecular-level understanding of graphene formation on Ni during the MSR reaction is still elusive. First principles-based approaches, such as Density Functional Theory (DFT) calculations, can provide valuable insight into the mechanism of graphene growth in the MSR reaction. It is, however, critical that a DFT model of this reaction can accurately describe the interactions of Ni(111) with the MSR intermediates as well as graphene. Crucially, these interactions include van der Waals forces, making the choice of a proper DFT functional a subject of debate, as there are several dispersion-inclusive functionals available in the literature. In this work, a systematic benchmark study has been carried out to identify a suitable DFT functional for the graphene and MSR system. The binding energies of graphene and important MSR species were computed on Ni(111) using GGA functionals, DFT-D3 and van der Waals density functionals (vdW-DF). Comparisons of these binding energies with published experimental data reveal that the GGA functionals are inadequate for the graphene-Ni(111) system. Among the vdW-DF, optB88-vdW predicts the binding energy of graphene with high accuracy; however, its predictions significantly deviate from the experimental binding energies of CO and O. Among DFT-D3 functionals, PBE-D3 was found to have a reasonable predictive accuracy for most MSR species (excluding the CO adsorbate). Overall, no single DFT functional could estimate the binding energies of all the species with equally high accuracy. Our benchmarks guide the selection of DFT functionals for simulations of MSR and could aid in the future development of predictive quality functionals

Performance-Governing Transport Mechanisms for Heat Pipes at Ultra-thin Form Factors

Heat pipes and vapor chamber heat spreaders offer a potential solution to the increasing thermal management challenges in thin-form-factor mobile computing platforms, where efficient spreading is required to simultaneously prevent overheating of internal components and formation of hot regions on the device exterior surfaces. Heat pipe performance limitations unique to such ultrathin form factors and the key heat transfer mechanisms governing the performance must be characterized. A thermal resistance network model and a detailed 2-D numerical model are used to analyze the performance of heat pipes under these conditions. A broad parametric study of geometries and heat inputs using the reduced-order model helps delineate the performance thresholds within which the effectiveness of a heat pipe is greater than a comparable solid heat spreader. A vapor-phase threshold unique to ultrathin heat pipes operating at low-power inputs is observed. At this threshold, the vapor-phase thermal resistance imposed by the saturation pressure/ temperature gradient in the heat pipe causes a crossover in the thermal resistance relative to a solid heat spreader. The higher fidelity numerical model is used to assess the accuracy of the resistance network model and to verify the validity and applicability of each assumption made regarding the transport mechanisms. Key heat transfer mechanisms not captured by the reducedorder thermal network models are identified. These include the effects of boundary conditions on the interface mass flux profile, convective effects on the vapor core temperature drop, and 2-D conduction on smearing of evaporation/condensation mass flux into the adiabatic section

Single-electron latch with granular film charge leakage suppressor

A single-electron latch is a device that can be used as a building block for Quantum-dot Cellular Automata (QCA) circuits. It consists of three nanoscale metal "dots" connected in series by tunnel junctions; charging of the dots is controlled by three electrostatic gates. One very important feature of a single-electron latch is its ability to store ("latch") information represented by the location of a single electron within the three dots. To obtain latching, the undesired leakage of charge during the retention time must be suppressed. Previously, to achieve this goal, multiple tunnel junctions were used to connect the three dots. However, this method of charge leakage suppression requires an additional compensation of the background charges affecting each parasitic dot in the array of junctions. We report a single-electron latch where a granular metal film is used to fabricate the middle dot in the latch which concurrently acts as a charge leakage suppressor. This latch has no parasitic dots, therefore the background charge compensation procedure is greatly simplified. We discuss the origins of charge leakage suppression and possible applications of granular metal dots for various single-electron circuits.Comment: 21 pages, 4 figure

Metallurgy of Complex Pb, Cu and Zinc Sulfides

For the winning of Pb, Cu and from sulfides ores by conventional methods, it is essential that these be beneficiated to high grade concentrates. The ore mine- rals in polymetallic and complex deposits are often found to be in close mutual penetration with each other and to the non-metallic gangue.In many cases where the attempts have been made to concentrate these ores; it is either difficult to obtain - a suitable grade of the concentrate by conventional flotation methods or the recovery of metals into the respective concentrate is poor. Zinc that finds its way to a copper concentrate is always discarded in the slag as a waste, while copper in a Pb concentrate leads to serious smelting problems. In such cases the cost of production by a smelting process becomes unfavourable and new approaches to process these ores become more attractive. Hydrometallurgical processes, based on leach-ing and precipitation alone, or in combination with conv-entional extractive metallurgical methods will play an important role in meeting the requirements of such complex ores. Such processes can more easily be adopted to small scale operation than conventional smelting and refining

A two-product inventory system with product interaction

In this paper, we study a two-component continuous review inventory system. We assume that demand occurs according to a Poisson process and that a demand can be satisfied only if both the components are available in the inventory. Back-orders are not permitted. We assume that the lead-time distribution of one product is arbitrary and the other is exponential. Identifying the underlying process as a semi-regeneration process we find the stationary distribution of the inventory level, the performance measures such as mean stationary rate of number of lost demands, the demands and the reorders made. A numerical example illustrates the results.Die artikel ondersoek 'n tweekomponent- deurlopende oorsigvoorraadstelsel. Daar word aanvaar dat aanvraag 'n Poissonproses is en dat aanvraag slegs bevredig kan word indien beide die komponente in die voorraad beskikbaar is. Agterstallige bestellings word nie toegelaat nie. Daar word aanvaar dat die lewertydverdeling van die een produk arbitrêr en die ander eksponensieël is. Indien die onderliggende proses as 'n semigenerasieproses geïdentifiseer word, kan die stasionêre verspreiding van die voorraadvlak bepaal word. Maatstawwe van vertoning soos mediaan- stasionêre koers van die hoeveelheid verlore aanvraag, die aanvraag en herbestellings wat gedoen is word bepaal. 'n Numeriese voorbeeld illustreer die resultate.http://sajie.journals.ac.z

Electricity load forecasting with artificial neural networks

Artificial neural networks are powerful tools for time series forecasting. The problem addressed in this article is to do multi-step prediction of a stationary time series, and to find the associated prediction limits. Artificial neural network models for time series are non-linear. However, results that are applicable to linear models are sometimes mistakenly applied to non-linear models. One example where this is observed is in multi-step forecasting. A bootstrap method is proposed to calculate one- and multi-step predictions and prediction limits. The results are applied to an electricity load time series as well as to a pure autoregressive time series.Kunsmatige neurale netwerke is kragtige instrumente vir tydreeksvoorspelling. In hierdie artikel word multistap-vooruitberaming van ‘n stasionêre tydreeks en die gepaardgaande vertroueinterval behandel. Resultate wat slegs geldig is vir lineêre modelle word soms verkeerdelik op neurale netwerkmodelle toegepas. ‘n Voorbeeld hiervan kom in multistap-voorspelling voor. ‘n Skoenlusmetode, word voorgestel waarvolgens eenstap- en multistap- voorspellings en vertroueintervalle bereken kan word. Die resultate word op ‘n elektrisiteitslastydreeks en op ‘n suiwer outoregressiewe tydreeks toegepas.http://sajie.journals.ac.z