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Objectives Literature from stroke and cardiac hospital admissions demonstrate a higher prevalence of undiagnosed type 2 diabetes compared with the general population. Fewer diabetes screening studies exist in the general medicine population, none of which have been based in Canada. Our primary objective in this study was to determine the prevalence of probable undiagnosed diabetes (glycated hemoglobin [A1C]≥6.5%) in hospitalized medicine patients. Secondary objectives were to identify the prevalence of undiagnosed dysglycemia (A1C≥6.0%) and the subsequent management of emergent cases. Methods In this prospective cohort study, adult patients admitted to internal medicine at a tertiary hospital in Ontario were screened for diabetes using an A1C test over a 3-month period. Baseline demographics and outcomes were compared using t tests, chi-square tests and Fisher’s exact tests for normoglycemia, undiagnosed dysglycemia and probable undiagnosed diabetes. A regression analysis was performed to identify any relationships between various cardiovascular-related risk factors and A1C. Results A total of 53 adult patients were enrolled. The prevalence of probable undiagnosed diabetes and undiagnosed dysglycemia was 7.5% (n=4) and 30.2% (n=16), respectively. Implementation of diabetes management strategies and/or documentation of the finding occurred in 4 of 16 patients. Regression analysis showed no relationship between either cardiovascular-related risk factors or admission glucose with A1C. Conclusions A broader screening approach may capture previously undiagnosed cases of diabetes that do not belong to traditionally at-risk populations. Future studies should focus on identifying risk factors for undiagnosed dysglycemia in hospitalized patients, including ethnicity and barriers to community access, so that appropriate screening programs can be developed.

The National Association of Pharmacy Regulatory Authorities (NAPRA) Model Standards for non-hazardous sterile preparations and the model standards for pharmacy compounding of hazardous sterile preparations, calls for partially used single dose vials to be used or discarded within six hours of first access. This may lead to significant wastage, particularly with less utilized and expensive medications like oncology treatments. If demonstrated that sterility of these partially used vials can be maintained through a compounding procedure, there may be an opportunity to consider their re-uses. The primary objective is to determine the ability of a compounding procedure, including a closed system transfer device (CSTD), to maintain sterility for partially used vials at two compounding centres at Trillium Health Partners. A secondary objective was to evaluate a novel method for verifying sterility. A CSTD was incorporated into the standard compounding methods at two hazardous compounding centres. Using growth media to detect any bacterial or fungal contamination that might have occurred during compounding, storage, and repeated access, the vials were tested in various growth conditions. There was no growth noted in all compounded samples. The CSTD, when used in our environment with certified personnel, maintained sterility for 14 days, even with repeated access. This study demonstrates that under our local compounding procedure using CSTD we were able to maintain vial sterility when stored under typical conditions and accessed several times for up to 14 days. This method may be considered to assess a facility’s local compounding procedures and provide valuable information regarding storage and utilization of partial vials, which may result in reduced waste and cost avoidance for the health care system.

Technological breakthroughs in electron microscopy (EM) have made it possible to solve structures of biological macromolecular complexes and to raise novel challenges, specifically related to sample preparation and heterogeneous macromolecular assemblies such as DNA-protein, protein-protein, and membrane protein assemblies. Here, we built a V-shaped DNA origami as a scaffolding molecular system to template proteins at user-defined positions in space. This template positions macromolecular assemblies of various sizes, juxtaposes combinations of biomolecules into complex arrangements, isolates biomolecules in their active state, and stabilizes membrane proteins in solution. In addition, the design can be engineered to tune DNA mechanical properties by exerting a controlled piconewton (pN) force on the molecular system and thus adapted to characterize mechanosensitive proteins. The binding site can also be specifically customized to accommodate the protein of interest, either interacting spontaneously with DNA or through directed chemical conjugation, increasing the range of potential targets for single-particle EM investigation. We assessed the applicability for five different proteins. Finally, as a proof of principle, we used RNAP protein to validate the approach and to explore the compatibility of the template with cryo-EM sample preparation.

The ability to self-assemble DNA nanodevices with programmed structural dynamics that can sense and respond to the local environment can enable transformative applications in fields including mechanobiology and nanomedicine. The responsive function of biomolecules is often driven by alterations in conformational distributions mediated by highly sensitive interactions with the local environment. In this review, the current state-of-the-art in constructing complex DNA geometries with dynamic and mechanical properties to enable a molecular scale force measurement is first summarized. Next, an overview of engineering modular DNA devices that interact with cell surfaces is highlighted detailing examples of mechanosensitive proteins and the force-induced dynamic molecular interaction on the downstream biochemical signaling. Finally, the challenges and an outlook on this promising class of DNA devices acting as nanomachines to operate at a low piconewton range suitable for a majority of biological effects or as hybrid materials to achieve higher tension exertion required for other biological investigations, are discussed.

Background: Under Ontario’s Public Hospitals Act, the scope of professional practice of hospital pharmacists is approved by each hospital’s medical advisory committee. Some Ontario hospitals have adopted policies or medical directives related to prescription modification, allowing pharmacists to broadly adapt, discontinue, hold, or renew prescriptions as part of their clinical scope of practice. Objectives: The primary objective of this study was to describe Ontario hospital pharmacists’ perception of their readiness to independently modify prescriptions. The secondary objectives of this study were to gather opinions on the perceived benefits, drawbacks, facilitators, and barriers to prescription modification by pharmacists and to determine how various factors affect perceived readiness. Methods: A confidential web-based survey with Likert-type quantitative questions and qualitative open-ended questions was distributed to 936 hospital pharmacists in Ontario between May and July 2019. Mean scores were calculated for the following constructs affecting prescription modification: self-efficacy, support from the practice environment, and support from interprofessional relationships. Independent t tests were conducted to compare responses between subgroups of interest. The answers to open-ended questions were analyzed thematically. Results: The survey had a 29% response rate (n = 271). The mean self-efficacy score was 5.2 out of 7 (standard deviation [SD] 1.0, Cronbach α = 0.88), equivalent to “quite sure”. The mean score for support from the practice environment was 3.3 out of 5 (SD 0.4, Cronbach α = 0.75), equivalent to “not a factor”. The mean score for support from interprofessional relationships was 4.2 out of 5 (SD 0.1, Cronbach α = 0.80), equivalent to “weak support”. Improved efficiency of care, timelier interventions to improve medication safety and efficacy, and improved interprofessional collaboration were cited as benefits of prescription modification by pharmacists. Potential for inappropriate decision-making and miscommunication were cited as concerns. Respondents in hospitals who were already performing prescription modification reported higher self-efficacy to modify prescriptions in clinical areas of both familiarity and unfamiliarity and greater support from prescribers. Conclusions: A large proportion of respondents to a survey of Ontario hospital pharmacists expressed an encouraging level of readiness to independently modify prescriptions. Responses to open-ended questions in this study provided valuable insights to inform widespread adoption of this practice change. RÉSUMÉ Contexte : En vertu de la Loi sur les hôpitaux publics de l’Ontario, le comité consultatif de chaque hôpital approuve l’élargissement de la pratique professionnelle des pharmaciens d’hôpitaux. Certains hôpitaux de l’Ontario ont adopté des politiques ou des directives médicales concernant la modification de la prescription. Celles-ci autorisent les pharmaciens à adapter, cesser, suspendre ou renouveler largement les prescriptions dans le cadre de leur champ de pratique. Objectifs : L’objectif principal de cette étude visait à décrire la perception des pharmaciens d’hôpitaux de l’Ontario de leur degré de préparation à modifier des prescriptions de manière indépendante. Les objectifs secondaires consistaient à recueillir les opinions sur les avantages, les inconvénients, les éléments de facilitation et les obstacles perçus par les pharmaciens au sujet de la modification de la prescription et de définir comment divers facteurs influençaient la perception de leur degré de préparation. Méthodes : Entre mai et juillet 2019, 936 pharmaciens d’hôpitaux en Ontario ont reçu une enquête confidentielle menée sur Internet comportant des questions quantitatives de type Likert et des questions ouvertes qualitatives. Les scores médians ont été calculés pour les concepts suivants liés à la modification de la prescription : l’autoefficacité, le soutien de l’environnement de pratique et le soutien des relations interprofessionnelles. Des tests t indépendants ont été menés pour comparer les réponses entre les sous-groupes sous-groupes qui intéressaient les auteurs. Les réponses aux questions ouvertes ont été analysées par thème. Résultats : Le taux de réponses à l’enquête se montait à 29 % (n = 271). Le score moyen pour le thème « Autoefficacité » était de 5,2 sur 7 (écart type [ET] 1, Cronbach α = 0,88), ce qui équivaut à la réponse « Assez certain ». Le score moyen pour le thème « Soutien de l’environnement de pratique » était de 3,3 sur 5 (ET 0,4, Cronbach α = 0,75), ce qui équivaut à la réponse « N’est pas un facteur ». Le score moyen pour le thème « Relations interprofessionnelles » était de 4,2 sur 5 (ET 0,1, Cronbach α = 0,80), ce qui équivaut à la réponse « Soutien faible ». Les pharmaciens ont cité l’amélioration de l’efficacité des soins, les interventions en temps opportun visant à améliorer l’innocuité et l’efficacité des médicaments ainsi que l’amélioration de la collaboration interprofessionnelle comme étant des avantages de la modification indépendante des prescriptions. Ils ont aussi indiqué que le risque de prise de décision inappropriée ainsi que la mauvaise communication constituaient pour eux un sujet de préoccupation. Les répondants qui pratiquaient déjà la modification de la prescription en milieu hospitalier ont indiqué un gain d’autoefficacité de la modification des prescriptions dans des domaines cliniques qui leur sont familiers ou non, ainsi qu’un plus grand soutien de la part des prescripteurs. Conclusions : Une grande partie des répondants à une enquête menée auprès de pharmaciens d’hôpitaux de l’Ontario ont jugé que leur degré de préparation à la modification indépendante des ordonnances était prometteur. Les réponses aux questions ouvertes de cette étude fournissent des éclaircissements précieux sur l’adoption généralisée de ce changement de pratique.

IntroductionPatients transitioning between hospital and home are at risk of experiencing adverse drug events. Hospital-based care teams require a better understanding of how therapeutic decisions and patient risk factors impact adverse health outcomes following discharge. Objectives and ApproachThe objective was to describe medications prescribed at discharge and quantify the association between these medication classes and risk of emergency department (ED) visits within 30 days. A retrospective, population-based cohort study was conducted using linked health administrative databases of adults discharged from hospital to the community between April 2016-March 2017, in Ontario, Canada. To distinguish medications prescribed at discharge from those by community providers, we examined medications dispensed in the 30-days following hospitalization but prior to another healthcare encounter (physician visit, ED visit, or rehospitalization). Adjusted logistic regression was used to determine the association between medication classes at discharge and ED visits in 30 days post discharge. ResultsOur study cohort included 214, 011 patients. Median age was 76 (IQR:66-82), 52% were females, 92% were discharged home and 8% were discharged to long term care. Patients were dispensed a median of 3 medications (IQR: 2-6). The most common medications included hydromorphone (16% of all patients, 71% of which represented new use), pantoprazole (15% of patients, 40% new use), furosemide (13% of patients, 34% new use), amlodipine (10% of patients, 35% new use) and oxycodone (9% of patients, 70% new use). To account for confounding by indication, we adjusted for age, sex, discharge service, discharge disposition, in hospital diagnoses and length of stay. Medications which were most highly associated with an increased risk of ED visits included antipsychotics, antiepileptics, anti-infectives, systemic corticosteroids, antihypertensives and cardiac stimulants. Conclusion / ImplicationsCharacterizing potential medication related harm in the 30-days following hospitalization is an important first step in understanding which patients may benefit most from hospital-based medication related interventions.

Nuclease colicins are antibacterial proteins produced by certain strains of E. coli to reduce competition from rival strains. These colicins are generally organized with an N-terminal transport (T)-domain, a central receptor binding (R)-domain, and a C-terminal cytotoxic nuclease domain. These colicins are always produced in complex with an inhibitory immunity protein, which dissociates prior entrance of the cytotoxic domain in the target cell. How exactly colicins traverse the cell envelope is not understood, yet this knowledge is important for the design of new antibacterial therapies. In this report, we find that the cytotoxic rRNAse domain of colicin E3, lacking both T- and R-domains, is sufficient to inhibit cell growth provided the immunity protein Im3 has been removed. Thus, while the T-domain is needed for dissociation of Im3, the rRNAse alone can associate to the cell surface without R-domain. Accordingly, we find a high affinity interaction (Kd ~1-2μM) between the rRNAse domain and lipopolysaccharides (LPS). Furthermore, we show that binding of ColE3 to LPS destabilizes the secondary structure of the toxin, which is expectedly crucial for transport through the narrow pore of the porin OmpF. The effect of LPS on binding and unfolding of ColE3 may be indicative of a broader role of LPS for transport of colicins in general.

TonB-dependent transporters are β-barrel outer membrane proteins occluded by a plug domain. Upon ligand binding, these transporters extend a periplasmic motif termed the TonB box. The TonB box permits the recruitment of the inner membrane protein complex TonB-ExbB-ExbD, which drives import of ligands in the cell periplasm. It is unknown precisely how the plug domain is moved aside during transport nor have the intermediate states between TonB recruitment and plug domain movement been characterized biochemically. Here we employ nanodiscs, native gel electrophoresis, and scintillation proximity assays to determine the binding kinetics of vitamin B12 to BtuB. The results show that ligand-bound BtuB recruits a monomer of TonB (TonB∆1-31), which in turn increases retention of vitamin B12 within the transporter. The TonB box and the extracellular residue valine 90 that forms part of the vitamin B12 binding site are essential for this event. These results identify a novel step in the TonB-dependent transport process. They show that TonB binding to BtuB trap the ligand, possibly until the ExbB-ExbD complex is activated or recruited to ensure subsequent transport.

Membrane proteins are difficult to work with due to their insolubility in aqueous solution and quite often their poor stability in detergent micelles. Here, we present the peptidisc for their facile capture into water-soluble particles. Unlike the nanodisc, which requires scaffold proteins of different lengths and precise amounts of matching lipids, reconstitution of detergent solubilized proteins in peptidisc only requires a short amphipathic bi-helical peptide (NSPr) and no extra lipids. Multiple copies of the peptide wrap around to shield the membrane-exposed part of the target protein. We demonstrate the effectiveness of this ‘one size fits all’ method using five different membrane protein assemblies (MalFGK2, FhuA, SecYEG, OmpF, BRC) during ‘on-column’, ‘in-gel’, and ‘on-bead’ reconstitution embedded within the membrane protein purification protocol. The peptidisc method is rapid and cost-effective, and it may emerge as a universal tool for high-throughput stabilization of membrane proteins to advance modern biological studies., eLife digest Surrounding every living cell is a biological membrane that is largely impermeable to water-soluble molecules. This hydrophobic (or “water-hating”) barrier preserves the contents of the cell and also regulates how the cell interacts with its environment. This latter function is critical and relies on a class of proteins that are embedded within the membrane and are also hydrophobic. The hydrophobic nature of membrane proteins is however inconvenient for biochemical studies which usually take place in water-based solutions. Therefore, membrane proteins are under-represented in biological research compared to the water-soluble ones, even though roughly one quarter of a cell’s proteins are membrane proteins. Researchers have developed a few tricks to keep membrane proteins soluble after they have been extracted from the membrane. An old but popular technique makes use of detergents, which are chemicals with opposing hydrophobic and hydrophilic properties (hydrophilic literally means “water-loving”). However, even mild detergents can damage membrane proteins and will sometimes lead to experimental artifacts. More recent tricks to stabilize membrane proteins without detergents have been described but remain laborious, costly or difficult to perform. To overcome these limitations, Carlson et al. developed a simple method to stabilize membrane proteins without detergent. Called the “peptidisc”, the method uses multiple copies of a unique peptide – a short sequence of the building blocks of protein – that had been redesigned to have optimal hydrophobic and hydrophilic properties. The idea was that the peptides would wrap around the hydrophobic parts of the membrane protein, and shield them from the watery solution. Indeed, when Carlson et al. mixed this peptide with five different membrane proteins from bacteria, all were perfectly soluble and functional without detergent. The ideal ratio of peptide needed to form a peptidisc around each membrane protein was reached automatically, without having to test many different conditions. This indicates that the peptidisc acts like a “one size fits all” scaffold. The peptidisc is a new tool that will allow more researchers, including those who are not expert biochemists, to study membrane proteins. This will yield a better understanding of the structure of a cell’s membrane and how it interacts with the environment. Since the approach is both simple and easy to apply, more membrane proteins can now also be included in high-throughput searches for potential new drugs for various medical conditions.

The 'safety lamp' invented by Humphrey Davy in 1815 utilised the cooling effect of metal gauze to prevent the flame of a candle or oil lamp (essential for illumination in mines) from passing through such a screen. It is therefore rendered unable to ignite any potentially explosive mixture of air and methane in the atmosphere surrounding the lamp. A number of experimental demonstrations are detailed to illustrate this effect, and show how the lamp could also indicate the presence of methane in the air of a coal mine.

The hydraulic impulse pump utilizes a fraction of the momentum of a flowing stream to lift a small portion of that water to a higher level. There it may be accumulated in an elevated cistern to provide sufficient water for several families, for the pump works 24 h a day with no additional source of energy. The operation of the pump is described, along with a working demonstration model constructed from plastic waste pipe and fittings.

TonB-dependent membrane receptors from bacteria have been analyzed in detergent-containing solution, an environment that may influence the role of ligand in inducing downstream interactions. We report reconstitution of FhuA into a membrane mimetic: nanodiscs. In contrast to previous results in detergent, we show that binding of TonB to FhuA in nanodiscs depends strongly on ferricrocin. The stoichiometry of interaction is 1:1 and the binding constant KD is ~200nM; an equilibrium affinity that is ten-fold lower than reported in detergent. FhuA in nanodiscs also forms a high-affinity binding site for colicin M (KD ~3.5nM), while ferricrocin renders FhuA refractory to colicin binding. Together, these results demonstrate the importance of the ligand in regulating receptor interactions and the advantages of nanodiscs to study β-barrel membrane proteins in a membrane-like environment.

The operation of the puzzling 'forever spin' top is explained. This toy makes an intriguing basis for discussion of the physical principles involved.

Details are given for the conversion of an inexpensive webcam to a camera specifically sensitive to the near infrared (700?1000?nm). Some experiments and practical applications are suggested and illustrated.

In his De Magnete William Gilbert claims that it is possible to make a magnet by hammering a red-hot bar of wrought iron arranged north–south on an anvil. This is contrary to modern ideas concerning the ‘Curie temperature’ (770°C for carbon steel), and to the recognized susceptibility of steel magnets to mechanical abuse. It has proved impossible to replicate Gilbert's technique experimentally. Only lengthy cold hammering of hardened carbon steel specimens on a large ferrous anvil produced weak permanent magnets.

233 Background: Trillium Health Partners (THP) is a large community oncology practice that has a culture of quality and safety. An investigation was triggered by a perceived increase in the rate of P-HSR during a weekly quality huddle in the chemotherapy suite. At the time THP had no formal hypersensitivity reaction tracking process. A retrospective review of P-HSR over the preceding 18 months identified an increase in reaction rates from a baseline of 1% to 4.5% that started 3 months prior to the raised concern. Methods: A systematic quality review was undertaken to identify triggers for the change and to identify steps to decrease P-HSR to baseline. There was no identified change in premedication, administration or compounding practice and no association with drug or lot number was identified. The increase in P-HSR was coincident with a change in the intravenous (IV) pumps and tubing system across the hospital. The change in IV pumps introduced several potential triggers including: a change in the options for priming the IV tubing which introduced a potential for variable concentrations of drug reaching the patient at the outset of the infusion, an interaction between drug and IV tubing, and a doubling of the IV tubing length which could result in incomplete delivery of the premedication. Results: Sequential practice changes were introduced to address each potential driver including i) a slow infusion protocol for first 2 cycles, ii) alternative tubing sets, iii) practice alert regarding potential for under-delivery of premedication. Over time P-HSR trended down towards the historic baseline, no single intervention had a sustained impact, although the practice alert regarding the administration of premedication seemed to induce the most change. A step wise withdrawal of interventions that were felt to be non impactful is underway. Conclusions: Although no clear cause for the increase in P-HSR was identified the systematic quality review resulted in improved standardization of nursing practice for chemotherapy delivery and the methodical approach also lead to the establishment of a more comprehensive hypersensitivity reporting system at THP.

A coherer is a bistable device based on metal filings loosely confined between solid metal electrodes. This granular material normally exhibits a very high electrical resistance (tens of kilohms), but passage of the high-frequency current generated by reception of a radio signal causes it to 'cohere' into a comparatively low resistance condition (tens of ohms). This state persists until the device is mechanically disturbed, whereupon the high resistance state is restored. This characteristic was employed by scientists in the 1890s to detect radio waves, and applied commercially by Marconi in his 'wireless' telegraph. It is easy to make a working coherer and directions are given for operating it from a distance with a spark transmitter based on a piezoelectric gas igniter. Incorporation of an 'aerial' and 'earth' enable a range of 7 m to be achieved and simple signals may be transmitted.

The extreme pressures that are generated when water freezes were traditionally demonstrated by sealing a small volume in a massive cast iron 'bomb' and then surrounding it with a freezing mixture of ice and salt. This vessel would dramatically fail by brittle fracture, but no quantitative measurement of bursting pressure was available. Calculation suggests a maximum of about 55 MPa (8000 psi) might have been achieved, with some 2.3% of the water frozen into a hollow shell around the interior of the vessel. In a sufficiently strong alloy steel container the pressure might rise to a maximum of 210 MPa (30 460 psi), this limiting figure being due to the collapse of ordinary ice (ice I) to the denser forms ice II or ice III.

The static and dynamic coefficients of friction are defined, and values from 0.3 to 0.6 are quoted for common materials. These drop to about 0.15 when oil is added as a lubricant. Water ice at temperatures not far below 0 °C is remarkable for low coefficients of around 0.05 for static friction and 0.04–0.02 for dynamic friction, but these figures increase as the temperature diminishes. Reasons for the slipperiness of ice are summarized, but they are still not entirely clear. One hypothesis suggests that it is related to the transient formation of a lubricating film of liquid water produced by frictional heating. If this is the case, some composition melting a little above ambient temperatures might provide a skating rink that did not require expensive refrigeration. Various compositions have been tested, but an entirely satisfactory material has yet to be found.

Robert Hooke is commonly thought of as the inventor of ‘Hooke's joint’ or the ‘universal joint’. However, it is shown that this flexible coupling (based on a four-armed cross pivoted between semicircular yokes attached to two shafts) was in fact known long before Hooke's time but was always assumed to give an output exactly matching that of the input shaft. Hooke carefully measured the relative displacements of the two axes, and found that if one were inclined to the other, uniform rotation of the input produced a varying rate of rotation of the output. He also recognized that this variable rate exactly corresponded to the movement of the shadow of a gnomon across the face of a sundial, as generated by the projection of the uniform motion of the Sun around an inclined polar axis. He therefore proposed that a ‘mechanical sundial’ might be made by coupling a 24-hour clock movement (with its hour shaft at the appropriate inclination) to a pointer via a universal joint. This proposal has been investigated both practically and mathematically, and shown to be valid. Hooke's studies of the universal joint caused it to be identified with his name, and it has ultimately proved far more important as a rotary coupling than as a sundial analogue. More complex versions subsequently designed by Hooke included provision for two basic couplings to be linked by an intermediate shaft. With appropriate setting of phase and shaft angles this ‘double Hooke's joint’ could annul the variable output velocity characteristic of the single universal. It has proved invaluable for modern automotive transmissions.

Contributing editor Alan Mills reports from October's LED 2005 conference in San Diego, California, where delegates heard how the recently achieved record LED flux levels have opened up a large portion of the general lighting market to LED penetration, at least on the basis of cost of ownership.

In the early 1800s galvanometers could be constructed with the fine gauges of silk-covered copper or silver wires produced for decorative purposes, but when Faraday was making his classic electrica...

The lodestone is an extremely rare form of the mineral magnetite (Fe3O4) that occurs naturally as a permanent magnet. It therefore attracts metallic iron as well as fragments of ordinary ‘inert’ magnetite. This ‘magic’ property was known to many ancient cultures, and a powerful lodestone has always commanded a high price. By the eleventh century AD the Chinese had discovered that a freely suspended elongated lodestone would tend to set with its long axis approximately north–south, and utilized this property in the magnetic compass. They also appear to have discovered that this invaluable characteristic could be handed‐on to a steel needle if the latter were contacted with, or stroked by, a lodestone. The magnetism of the lodestone was scientifically investigated by William Gilbert in the sixteenth century, when he defined its ‘poles' and the well‐known rule that ‘like poles repel, unlike attract’. He also studied ‘inclination’ and ‘variation’, and means to aid the preservation of magnetic power. How to co...

Classic voltaic batteries of the silver/zinc and copper/zinc types are the ancestors of today's primary cells, and facilitated the development of many aspects of electrical technology. Nevertheless, they appear never to have been studied and evaluated in a quantitative manner, with results recorded in terms of volts, amps, ohms, and watts. Research of this nature is reported here, and has been conducted for the most part with copper/zinc cells. Log-log graphs of voltage versus load and current, and power versus load, are presented for many electrolyte systems. It has been shown that, although the textbook electrolyte of dilute sulphuric acid does work, it is an order of magnitude inferior to a solution containing some additional nitric acid. The latter diminishes the current-limiting phenomenon of polarization, and was in fact used by Davy, Faraday, and other early investigators. A quantitative consideration of Nicholson and Carlisle's discovery of the electrolysis of water with a silver/zinc voltaic pile is followed by examination of the electrolysis of pure water, trough batteries, and Davy's isolation of potassium and sodium. Every battery gives maximum power when its resistance is adjusted (by appropriate series/parallel connections) to match the resistance of the load; the maximum output of the 'Great Battery' of the Royal Institution is assessed at no more than 3 kW. The paper concludes with a note on the recognized hazard of long-term exposure to mercury vapour (produced by amalgamation of zinc electrodes in batteries) and its possible relevance to the health of Michael Faraday.

Circular wheels are so familiar on vehicles of all types that it is seldom realized that alternatives do exist. This short non-mathematical article describes Reuleaux and square wheels that, rolling along appropriate tracks, can maintain a moving platform at a constant height. Easily made working models lend themselves to demonstrations at science fairs and open days.

We describe the types of major institution health care resources consumed as a result of skeletal-related events (SREs) [ie, pathological fracture, bone surgery, radiation to bone, spinal cord compression].A retrospective multicenter chart review of cancer patients with bone metastases who experienced SREs was conducted. Patients with multiple SREs occurring during the same hospitalization within 21 days of each other were grouped into SRE clusters.We reviewed 156 patient charts from 4 Canadian institutions, accounting for 358 SREs and 259 SRE clusters. Of the total patients, 63% experienced 1 SRE; 19%, 2 SREs; 10%, 3 SREs; and 8%, ≥ 4 events. Health care resource utilization was captured for ≥ 90 days following each SRE: 54% of all SRE events resulted in an inpatient stay; 34% in an emergency visit; 85% of SREs required the use of diagnostic procedures (including radiography, magnetic resonance imaging, Computerized Axial Tomography scans, and radio scans); 57% required radiation treatment; 34% required a surgical procedure; 35% received outpatient treatment visits (ie, physiotherapy or occupational therapy). Bone surgery and spinal cord compression were more often associated with hospitalization than were other SRE types. Spinal cord compression was associated with the greatest number of inpatients stays (1.09 per SRE), longest duration of hospital stay (mean 26.18 days per SRE), and more outpatient visits, relative to other SRE types.Results of our Canadian retrospective study clearly demonstrate that SREs occur in cancer patients and each SRE is associated with considerable institutional consumption of health care resources.

Venous thromboembolism (VTE) causes significant morbidity and mortality in hospitalized medical populations; however, medical patients do not currently receive thromboprophylaxis beyond their hospital stay. We reviewed the real-life occurrence of VTE-related care for 100 days post-hospitalization in Calgary, Canada. Using medical visit records with a unique patient identifier number applied throughout the city’s hospitals, 989 high-risk patients were selected for review. Almost three-quarters of the elderly patients received appropriate prophylaxis while in hospital, and only 2% received prophylaxis on discharge. Over the 100-day follow-up, 21% of the patients presented with clinically suspected VTE, of which 3.8% had confirmed VTE. Patients with multiple risk factors (≥3) had the highest frequency of confirmed VTE (≥6.1%). This study suggests that the actual rate of VTE-related follow-up care in patients post-hospitalization is high in the first 100 days, particularly among those who have multiple risk factors, warranting consideration of extended thromboprophylaxis in this population.

Summary Altitude sundials do not require knowledge of the N-S direction to quantify time in terms of either seasonal or equal hours. Methods for determining the corresponding dial patterns are reviewed, and accurately computed data for a latitude of 51°N presented as horizontal, vertical, rectangular, and pillar dials on both timekeeping systems.

In October 1994 the Audit Commission published it's fifth triennial survey on the extent of computer fraud and abuse. Entitled "Opportunity makes a thief - an analysis of computer abuse". It makes disturbing reading. The survey was compiled from over 1000 responses to 5500 questionnaires distributed to a broad range of organizations covering both the public and private sectors. The Audit Commission is a British commission which is responsible for the statutory external audit of local authorities and water authorities in England and Wales.

The use of proton pump inhibitors (PPIs) has been implicated as a potential contributor to the development of Clostridium difficile-associated disease (CDAD) because of the ability of these drugs to substantially reduce the bactericidal effect of gastric acid. This study focused on the impact of PPIs, among other known risk factors, during an outbreak of CDAD in a hospital setting.The primary objective was to determine whether there was an association between current use of a PPI and the CDAD outbreak. Secondary objectives were to evaluate any correlations between the CDAD outbreak and past use of PPIs, use of antibiotics, diabetes mellitus, enteral feeding, cancer, gastrointestinal surgery, inflammatory bowel disease, and previous care or residence in an institutional setting.A retrospective case-control study was conducted. One hundred and fifty cases of hospital-acquired Clostridium difficile were identified. Patients were individually matched to controls for age, sex, date of admission to hospital, and hospital unit. The groups were compared with respect to each exposure.Eight case patients could not be matched with suitable controls. Therefore, data from 142 cases and 142 controls were analyzed. There was no association between current use of a PPI and the CDAD outbreak (odds ratio [OR] 1.0, 95% confidence interval [CI] 0.99-1.01). Similarly, there was no correlation between the CDAD outbreak and diabetes, enteral feeding, cancer, gastrointestinal surgery, inflammatory bowel disease, or previous care or residence in an institution. However, the development of CDAD was positively associated with use of antibiotics within the 30 days preceding the infection (OR 12.0, 95% CI 4.0-35.7) and with past use of a PPI (OR 2.4, 95% CI 1.4-4.3).The development of CDAD during a hospital outbreak was associated with use of antibiotics and with past, not current, use of PPIs.

SummaryDocumenting patterns and outcomes of venous thromboembolism (VTE) management and degree of adherence by clinicians to treatment guidelines could help identify remediable gaps in patient care. Prospective, clinical practice-based data from Canadian outpatient settings on management of VTE, degree of adherence with treatment guidelines and frequency of recurrent VTE and bleeding during follow-up was obtained in a multicentre, prospective observational study. From 12 Canadian centres, we assessed 868 outpatients with acute symptomatic VTE who received the low-molecular-weight heparin (LMWH) enoxaparin alone or with vitamin K antagonists (VKA), at baseline and at six months (or at the end of treatment, whichever came first). Index VTE was limb deep venous thrombosis (DVT) in 583 (67.2%) patients, pulmonary embolism (PE) with or without DVT in 262 (30.2%) patients, and unusual site DVT in 23 (2.6%) patients. VTE was unprovoked in 399 (46.0%) patients, associated with cancer in 74 (8.5%) patients, transient risk factors in 327 (37.7%) patients and hormonal factors in 68 (7.8%) patients. With regard to guideline adherence, 58 (7.3%) patients received 3 months. Only 38.1% of patients with transient VTE risk factors had received thromboprophylaxis. Our study provides useful information on clinical presentation, management and related outcomes in Canadian outpatients with VTE. Our results suggest there may be important gaps in use of thromboprophylaxis to prevent VTE and use of LMWH mono-therapy to treat cancer-related VTE.Note: Part of this study was presented as an Oral Abstract Presentation at the American Society of Hematology meeting, Dec. 4–7, 2010, Orlando, FL, USA.

Summary The true form of the seasonal-hour sundial, in both vertical and horizontal planes, has been calculated by spherical trigonometry and displayed with the aid of computer graphics. These grids are presented, and show that the hour lines are in fact shallow curves at sites not on the equator. The curvature becomes very apparent at latitudes exceeding 50°. The true seasonal-hour pattern for a vertical dial at a latitude of 52·6°N is compared with the equiangular scratch dial.

Background: The use of proton pump inhibitors (PPIs) has been implicated as a potential contributor to the development of Clostridium difficile–associated disease (CDAD) because of the ability of these drugs to substantially reduce the bactericidal effect of gastric acid. This study focused on the impact of PPIs, among other known risk factors, during an outbreak of CDAD in a hospital setting. Objectives: The primary objective was to determine whether there was an association between current use of a PPI and the CDAD outbreak. Secondary objectives were to evaluate any correlations between the CDAD outbreak and past use of PPIs, use of antibiotics, diabetes mellitus, enteral feeding, cancer, gastrointestinal surgery, inflammatory bowel disease, and previous care or residence in an institutional setting. Methods: A retrospective case–control study was conducted. One hundred and fifty cases of hospital-acquired Clostridium difficile were identified. Patients were individually matched to controls for age, sex, date of admission to hospital, and hospital unit. The groups were compared with respect to each exposure. Results: Eight case patients could not be matched with suitable controls. Therefore, data from 142 cases and 142 controls were analyzed. There was no association between current use of a PPI and the CDAD outbreak (odds ratio [OR] 1.0, 95% confidence interval [CI] 0.99–1.01). Similarly, there was no correlation between the CDAD outbreak and diabetes, enteral feeding, cancer, gastrointestinal surgery, inflammatory bowel disease, or previous care or residence in an institution. However, the development of CDAD was positively associated with use of antibiotics within the 30 days preceding the infection (OR 12.0, 95% CI 4.0–35.7) and with past use of a PPI (OR 2.4, 95% CI 1.4–4.3). Conclusions: The development of CDAD during a hospital outbreak was associated with use of antibiotics and with past, not current, use of PPIs. RESUME Contexte : L’emploi des inhibiteurs de la pompe a protons (IPP) jouerait un role dans l’apparition des maladies associees au Clostridium difficile (MACD) a cause de leur capacite a reduire considerablement l’effet bactericide de l’acide gastrique. Cette etude s’est penchee sur le role des IPP, parmi d’autres facteurs de risque connus, durant une eclosion de MACD dans un hopital. Objectifs : Le principal objectif etait de determiner s’il existait un lien entre l’utilisation actuelle d’un IPP et l’eclosion de MACD. Les objectifs secondaires etaient d’evaluer les correlations entre l’eclosion de MACD et l’utilisation anterieure d’IPP, l’utilisation d’antibiotiques, le diabete sucre, l’alimentation enterale, le cancer, les interventions chirurgicales gastrointestinales, la maladie inflammatoire de l’intestin et le fait d’avoir sejourne ou de vivre dans un etablissement. Methodes : On a effectue une etude cas-temoins retrospective. On a repertorie 150 cas de maladies nosocomiales associees au Clostridium difficile. Les patients ont ete apparies individuellement a des temoins en fonction de l’âge, du sexe, de la date d’hospitalisation et de l’unite de soins. Les groupes ont ete compares pour ce qui est de chaque exposition. Resultats : Huit cas n’ont pu etre apparies a des temoins convenables. Les donnees de 142 cas et de 142 temoins ont donc ete analysees. Aucune association n’a ete etablie entre l’utilisation actuelle d’IPP et l’eclosion de MACD (risque relatif approche [RRA] 1,0, intervalle de confiance a 95 % [IC] 0,99-1,01). De meme, on n’a observe aucune correlation entre l’eclosion de MACD et le diabete, l’alimentation enterale, le cancer, une intervention chirurgicale gastro-intestinale, la maladie inflammatoire de l’intestin ou le fait de vivre dans un etablissement. Cependant, on a etabli une correlation entre l’apparition de MACD et l’utilisation d’antibiotiques dans les 30 jours precedant l’infection (RRA 12,0, IC a 95 % 4,0-35,7) et l’utilisation anterieure d’IPP (RRA 2,4, IC a 95 % 1,4-4,3). Conclusions : On a etabli un lien entre l’apparition de MACD pendant une eclosion a l’hopital et l’utilisation d’antibiotiques ainsi que l’utilisation anterieure, mais pas actuelle, d’IPP.