227 research outputs found

    Real-time pair-feeding of animals

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    Automatic pair-feeding system was developed which immediately dispenses same amount of food to control animal as has been consumed by experimental animal that has free access to food. System consists of: master feeding system; slave feeding station; and control mechanism. Technique performs real time pair-feeding without attendant time lag

    Automatic real-time pair-feeding system for animals

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    A pair feeding method and apparatus are provided for experimental animals wherein the amount of food consumed is immediately delivered to a normal or control animal so that there is a qualitative, quantitative and chronological correctness in the pair feeding of the two animals. This feeding mechanism delivers precisely measured amounts of food to a feeder. Circuitry is provided between master and slave feeders so that there is virtually no chance of a malfunction of the feeding apparatus, causing erratic results. Recording equipment is also provided so that an hourly record is kept of food delivery

    Fabrication and characterization of dual function nanoscale pH-scanning ion conductance microscopy (SICM) probes for high resolution pH mapping

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    The easy fabrication and use of nanoscale dual function pH-scanning ion conductance microscopy (SICM) probes is reported. These probes incorporate an iridium oxide coated carbon electrode for pH measurement and an SICM barrel for distance control, enabling simultaneous pH and topography mapping. These pH-SICM probes were fabricated rapidly from laser pulled theta quartz pipets, with the pH electrode prepared by in situ carbon filling of one of the barrels by the pyrolytic decomposition of butane, followed by electrodeposition of a thin layer of hydrous iridium oxide. The other barrel was filled with an electrolyte solution and Ag/AgCl electrode as part of a conductance cell for SICM. The fabricated probes, with pH and SICM sensing elements typically on the 100 nm scale, were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and various electrochemical measurements. They showed a linear super-Nernstian pH response over a range of pH (pH 2–10). The capability of the pH-SICM probe was demonstrated by detecting both pH and topographical changes during the dissolution of a calcite microcrystal in aqueous solution. This system illustrates the quantitative nature of pH-SICM imaging, because the dissolution process changes the crystal height and interfacial pH (compared to bulk), and each is sensitive to the rate. Both measurements reveal similar dissolution rates, which are in agreement with previously reported literature values measured by classical bulk methods

    Nonorographic generation of Arctic polar stratospheric clouds during

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    [1] During December 1999, polar stratospheric clouds (PSCs) were observed in the absence of conditions conducive to generation by topographic gravity waves. The possibility is explored that PSCs can be generated by inertia gravity waves (IGW) radiating from breaking synoptic-scale Rossby waves on the polar front jet. The aerosol features on 7 and 12 December are selected for comparison with theory and with simulations using the University of Wisconsin Nonhydrostatic Modeling System (UWNMS). Consistent with Rossby adjustment theory, a common feature in the UWNMS simulations is radiation of IGW from the tropopause polar front jet, especially from sectors which are evolving rapidly in the Rossby wave breaking process. Packets of gravity wave energy radiate upward and poleward into the cold pool, while individual wave crests propagate poleward and downward, causing mesoscale variations in vertical motion and temperature. On 12 December the eastbound DC-8 lidar observations exhibited a fairly uniform field of six waves in aerosol enhancement in the 14-20 km layer, consistent with vertical displacement by a field of IGW propagating antiparallel to the flow, with characteristic horizontal and vertical wavelengths of 300and300 and 10 km. UWNMS simulations show emanation of a field of IGW upward and southwestward from a northward incursion of the polar front jet. The orientation and evolution of the aerosol features on 7 December are consistent with a single PSC induced by an IGW packet propagating from a breaking Rossby wave over western Russia toward the northeast into the coldest part of the base of the polar vortex, with characteristic period 9hours,verticalwavelength9 hours, vertical wavelength 12 km, and horizontal wavelength 1000km.Lineartheoryshowsthatforbothofthesecases,IGWenergypropagatesupwardat1000 km. Linear theory shows that for both of these cases, IGW energy propagates upward at 1 km/hour and horizontally at 100km/hour,withcharacteristictracespeed100 km/hour, with characteristic trace speed 30 m/s. The spatial orientation of the PSC along IGW phase lines is contrasted with the nearly horizontal filamentary structures in the PSC, which are indicative of flow streamlines. It is suggested that vertical displacement is a crucial factor in determining whether a PSC will form and that most PSCs are relatable to specific synoptic and mesoscale motions

    Outer-Sphere Contributions to the Electronic Structure of Type Zero Copper Proteins

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    Bioinorganic canon states that active-site thiolate coordination promotes rapid electron transfer (ET) to and from type 1 copper proteins. In recent work, we have found that copper ET sites in proteins also can be constructed without thiolate ligation (called “type zero” sites). Here we report multifrequency electron paramagnetic resonance (EPR), magnetic circular dichroism (MCD), and nuclear magnetic resonance (NMR) spectroscopic data together with density functional theory (DFT) and spectroscopy-oriented configuration interaction (SORCI) calculations for type zero Pseudomonas aeruginosa azurin variants. Wild-type (type 1) and type zero copper centers experience virtually identical ligand fields. Moreover, O-donor covalency is enhanced in type zero centers relative that in the C112D (type 2) protein. At the same time, N-donor covalency is reduced in a similar fashion to type 1 centers. QM/MM and SORCI calculations show that the electronic structures of type zero and type 2 are intimately linked to the orientation and coordination mode of the carboxylate ligand, which in turn is influenced by outer-sphere hydrogen bonding

    PRESS survey: PREvention of surgical site infection—a global pan-specialty survey of practice protocol

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    BackgroundSurgical site infections (SSI) complicate up to 40% of surgical procedures, leading to increased patient morbidity and mortality. Previous research identified disparities in SSI prevention guidelines and clinical practices across different institutions. The study aims to identify variations in SSI prevention practices within and between specialties and financial systems and provide a representation of existing SSI preventative measures to help improve the standardization of SSI prevention practices.MethodsThis collaborative cross-sectional survey will be aimed at pan-surgical specialties internationally. The study has been designed and will be reported in line with the CROSS and CHERRIES standards. An international study steering committee will design and internally validate the survey in multiple consensus-based rounds. This will be based on SSI prevention measures outlined in the CDC (2017), WHO (2018), NICE (2019), Wounds UK (2020) and the International Surgical Wound Complications Advisory Panel (ISWCAP) guidelines. The questionnaire will include demographics, SSI surveillance, preoperative, peri-operative and postoperative SSI prevention. Data will be collected on participants' surgical specialty, operative grade, of practice and financial healthcare system of practice. The online survey will be designed and disseminated using Qualtrics XM Platform™ through national and international surgical colleges and societies, in addition to social media and snowballing. Data collection will be open for 3 months with reminders, and raking will be used to ascertain the sample. Responses will be analyzed, and the chi-square test used to evaluate the impact of SSI prevention variables on responses.DiscussionCurrent SSI prevention practice in UK Vascular surgery varies considerably, with little consensus on many measures. Given the inconsistency in guidelines on how to prevent SSIs, there is a need for standardization. This survey will investigate the disparity in SSI preventative measures between different surgical fields and countries

    Wp index: A new substorm index derived from high-resolution geomagnetic field data at low latitude

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    Geomagnetic field data with high time resolution (typically 1 s) have recently become more commonly acquired by ground stations. Such high time resolution data enable identifying Pi2 pulsations which have periods of 40–150 s and irregular (damped) waveforms. It is well-known that pulsations of this type are clearly observed at mid- and low-latitude ground stations on the nightside at substorm onset. Therefore, with 1-s data from multiple stations distributed in longitude around the Earth's circumference, substorm onset can be regularly monitored. In the present study we propose a new substorm index, the Wp index (Wave and planetary), which reflects Pi2 wave power at low-latitude, using geomagnetic field data from 11 ground stations. We compare the Wp index with the AE and ASY indices as well as the electron flux and magnetic field data at geosynchronous altitudes for 11 March 2010. We find that significant enhancements of the Wp index mostly coincide with those of the other data. Thus the Wp index can be considered a good indicator of substorm onset. The Wp index, other geomagnetic indices, and geosynchronous satellite data are plotted in a stack for quick and easy search of substorm onset. The stack plots and digital data of the Wp index are available at the Web site (http://s-cubed.info) for public use. These products would be useful to investigate and understand space weather events, because substorms cause injection of intense fluxes of energetic electrons into the inner magnetosphere and potentially have deleterious impacts on satellites by inducing surface charging

    An observational national study of anaesthetic workload and seniority across the working week and weekend in the UK in 2016: the 6th National Audit Project (NAP6) Activity Survey

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    BACKGROUND: UK national anaesthetic activity was studied in 2013 but weekend working was not examined. Understanding changes since 2013 in workload and manpower distribution, including weekends, would be of value in workforce planning. METHODS: We performed an observational survey of NHS hospitals' anaesthetic practice in October 2016 as part of the 6th National Audit Project of the Royal College of Anaesthetists (NAP6). All cases cared for by an anaesthetist during the study period were included. Patient characteristics and details of anaesthetic conduct were collected by local anaesthetists. RESULTS: Responses were received from 342/356 (96%) hospitals. In total, 15 942 cases were reported, equating to an annual anaesthetic workload of ≈3.13 million cases. Approximately 95% (9888/10 452) of elective and 72% (3184/4392) of emergency work was performed on weekdays and 89% (14 145/15 942) of activity was led by senior (consultant or career grade) anaesthetists and 1.1% (180/15942) by those with <2 yr anaesthetic experience. During weekends case urgency increased, the proportion of healthy patients reduced and case mix changed. Cases led by senior anaesthetists fell to 80% (947/1177) on Saturday and 66% (342/791) on Sunday. Senior involvement in obstetric anaesthetic activity was 69% (628/911) during the week and 45% (182/402) at weekends, compared with 93% (791/847) in emergency orthopaedic procedures during the week and 89% (285/321) at weekends. Since 2013, the proportion of obese patients, elective weekend working, and depth of anaesthesia monitoring has increased [12% (1464/12 213) vs 2.8%], but neuromuscular monitoring has not [37% (2032/5532) vs 38% of paralysed cases]. CONCLUSIONS: Senior clinicians deliver most UK anaesthesia care, including at weekends. Our findings are important for any planned workforce reorganisation to rationalise 7-day working

    Anaesthesia, surgery, and life-threatening allergic reactions: epidemiology and clinical features of perioperative anaphylaxis in the 6th National Audit Project (NAP6)

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    BACKGROUND: Anaphylaxis during anaesthesia is a serious complication for patients and anaesthetists. METHODS: The 6th National Audit Project (NAP6) on perioperative anaphylaxis collected and reviewed 266 reports of Grades 3-5 anaphylaxis over 1 yr from all NHS hospitals in the UK. RESULTS: The estimated incidence was ≈1:10 000 anaesthetics. Case exclusion because of reporting delays or incomplete data means true incidence might be ≈70% higher. The distribution of 199 identified culprit agents included antibiotics (94), neuromuscular blocking agents (65), chlorhexidine (18), and Patent Blue dye (9). Teicoplanin comprised 12% of antibiotic exposures, but caused 38% of antibiotic-induced anaphylaxis. Eighteen patients reacted to an antibiotic test dose. Succinylcholine-induced anaphylaxis, mainly presenting with bronchospasm, was two-fold more likely than other neuromuscular blocking agents. Atracurium-induced anaphylaxis mainly presented with hypotension. Non-depolarising neuromuscular blocking agents had similar incidences to each other. There were no reports of local anaesthetic or latex-induced anaphylaxis. The commonest presenting features were hypotension (46%), bronchospasm (18%), tachycardia (9.8%), oxygen desaturation (4.7%), bradycardia (3%), and reduced/absent capnography trace (2.3%). All patients were hypotensive during the episode. Onset was rapid for neuromuscular blocking agents and antibiotics, but delayed with chlorhexidine and Patent Blue dye. There were 10 deaths and 40 cardiac arrests. Pulseless electrical activity was the usual type of cardiac arrest, often with bradycardia. Poor outcomes were associated with increased ASA, obesity, beta blocker, and angiotensin-converting enzyme inhibitor medication. Seventy per cent of cases were reported to the hospital incident reporting system, and only 24% to Medicines and Healthcare products Regulatory Agency via the Yellow Card Scheme. CONCLUSIONS: The overall incidence of perioperative anaphylaxis was estimated to be 1 in 10 000 anaesthetics

    Anaesthesia, surgery, and life-threatening allergic reactions: management and outcomes in the 6th National Audit Project (NAP6)

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    BACKGROUND: Anaphylaxis during anaesthesia is a serious complication for patients and anaesthetists. There is little published information on management and outcomes of perioperative anaphylaxis in the UK. METHODS: The 6th National Audit Project of the Royal College of Anaesthetists (NAP6) collected and reviewed 266 reports of Grade 3-5 anaphylaxis from all UK NHS hospitals over 1 yr. Quality of management was assessed against published guidelines. RESULTS: Appropriately senior anaesthetists resuscitated all patients. Immediate management was 'good' in 46% and 'poor' in 15%. Recognition and treatment of anaphylaxis were prompt in 97% and 83% of cases, respectively. Epinephrine was administered i.v. in 76%, i.m. in 14%, both in 6%, and not at all in 11% of cases. A catecholamine infusion was administered in half of cases. Cardiac arrests (40 cases; 15%) were promptly treated but cardiac compressions were omitted in half of patients with unrecordable BP. The surgical procedure was abandoned in most cases, including 10% where surgery was urgent. Of 54% admitted to critical care, 70% were level 3, with most requiring catecholamine infusions. Ten (3.8%) patents (mostly elderly with cardiovascular disease) died from anaphylaxis. Corticosteroids and antihistamines were generally administered early. We found no clear evidence of harm or benefit from chlorphenamine. Two patients received vasopressin and one glucagon. Fluid administration was inadequate in 19% of cases. Treatment included sugammadex in 19 cases, including one when rocuronium had not been administered. Adverse sequelae (psychological, cognitive, or physical) were reported in one-third of cases. CONCLUSIONS: Management of perioperative anaphylaxis could be improved, especially with respect to administration of epinephrine, cardiac compressions, and i.v. fluid. Sequelae were common
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