Design and construction of a point-contact spectroscopy rig with lateral scanning capability.

The design and realization of a cryogenic rig for point-contact spectroscopy measurements in the needle-anvil configuration is presented. Thanks to the use of two piezoelectric nano-positioners, the tip can move along the vertical (z) and horizontal (x) direction and thus the rig is suitable to probe different regions of a sample in situ. Moreover, it can also form double point-contacts on different facets of a single crystal for achieving, e.g., an interferometer configuration for phase-sensitive measurements. For the later purpose, the sample holder can also host a Helmholtz coil for applying a small transverse magnetic field to the junction. A semi-rigid coaxial cable can be easily added for studying the behavior of Josephson junctions under microwave irradiation. The rig can be detached from the probe and thus used with different cryostats. The performance of this new probe has been tested in a Quantum Design PPMS system by conducting point-contact Andreev reflection measurements on Nb thin films over large areas as a function of temperature and magnetic field.

Deep neuromuscular block improves the surgical conditions for laryngeal microsurgery.

BACKGROUND: Adequate neuromuscular block is required throughout laryngeal microsurgery. We hypothesized that the surgical conditions would improve under a deeper level of rocuronium-induced neuromuscular block. METHODS: Seventy-two patients undergoing laryngeal microsurgery were randomly allocated to either the 'post-tetanic counts 1-2' (PTC1-2) group or the 'train-of-four counts 1-2' (TOFcount1-2) group according to the level of neuromuscular block used. Two different doses of rocuronium (1.2 or 0.5 mg kg(-1)) were used after anaesthetic induction, and two respective targets of neuromuscular block (post-tetanic counts ≤2 or train-of-four count of 1 or 2) were used. Surgical conditions were assessed by the surgeon using a five-point rating scale (extremely poor/poor/acceptable/good/optimal), and clinically acceptable surgical conditions were defined as those which were rated acceptable, good, or optimal. The occurrence of vocal cord movement and postoperative adverse events was assessed. RESULTS: The surgical conditions were significantly different between the PTC1-2 and TOFcount1-2 groups (extremely poor/poor/acceptable/good/optimal: 0/2/1/7/26 and 3/10/2/14/7, respectively, P<0.001). The incidence of clinically acceptable surgical conditions was significantly higher in the PTC1-2 group than in the TOFcount1-2 group (94 vs 64%, P=0.003). The percentage of patients who exhibited vocal cord movement was significantly lower in the PTC1-2 group than in the TOFcount1-2 group (3 vs 39%, P<0.001). The incidence of postoperative adverse events was not significantly different except for the less frequent occurrence of mouth dryness in the PTC1-2 group (P=0.035). CONCLUSIONS: Deep neuromuscular block (post-tetanic count of 1-2) surgical conditions in patients undergoing laryngeal microsurgery improves. CLINICAL TRIAL REGISTRATION: NCT01980069.

Two-step fabrication technique of gold tips for use in point-contact spectroscopy.

For a successful point-contact spectroscopy (PCS) measurement, metallic tips of proper shape and smoothness are essential to ensure the ballistic nature of a point-contact junction. Until recently, the fabrication of Au tips suitable for use in point-contact spectroscopy has remained more of an art involving a trial and error method rather than an automated scientific process. To address these issues, we have developed a technique with which one can prepare high quality Au tips reproducibly and systematically. It involves an electronic control of the driving voltages used for an electrochemical etching of a gold wire in a HCl-glycerol mixture or a HCl solution. We find that a stopping current, below which the circuit is set to shut off, is a single very important parameter to produce an Au tip of desired shape. We present detailed descriptions for a two-step etching process for Au tips and also test results from PCS measurements using them.

Detection of microorganisms using terahertz metamaterials.

Microorganisms such as fungi and bacteria cause many human diseases and therefore rapid and accurate identification of these substances is essential for effective treatment and prevention of further infections. In particular, contemporary microbial detection technique is limited by the low detection speed which usually extends over a couple of days. Here we demonstrate that metamaterials operating in the terahertz frequency range shows promising potential for use in fabricating the highly sensitive and selective microbial sensors that are capable of high-speed on-site detection of microorganisms in both ambient and aqueous environments. We were able to detect extremely small amounts of the microorganisms, because their sizes are on the same scale as the micro-gaps of the terahertz metamaterials. The resonant frequency shift of the metamaterials was investigated in terms of the number density and the dielectric constants of the microorganisms, which was successfully interpreted by the change in the effective dielectric constant of a gap area.

An assessment of oropharyngeal airway position using a fibreoptic bronchoscope.

Selecting the appropriate oropharyngeal airway for safe and effective airway management is important in clinical practice. In this prospective observational study, we examined the position of the distal end of oropharyngeal airways using a fibreoptic bronchoscope. We enrolled 149 adults (72 men and 77 women). The correct airway size was determined by inserting four adult sizes Guedel airway (Hudson RCI; Teleflex Medical, Research Triangle, Park, NC, USA) (sizes 8, 9, 10 and 11) sequentially in anaesthetised patients. The 'best fit' airway was size 10 in 45 (62%) men, and size 9 in 58 (75%) women. However, when these airways were inserted, the distal end of the airway either touched or passed beyond the epiglottis tip in 20 (27%) men and six (8%) women, respectively. When a size-9 airway was inserted in men and a size-8 airway inserted in women, the distal ends were obstructed by the tongue in three (2%) patients. In conclusion, a size-9 airway in men and a size-8 airway in women are the most acceptable sizes for adults of average height.

Observation of the hybridization gap and Fano resonance in the Kondo lattice URu2Si2.

The nature of the second-order phase transition that occurs in URu2Si2 at 17.5 K remains puzzling despite intensive research. A key question emerging in the field is whether a hybridization gap between the renormalized bands can be identified as the "hidden" order parameter. We report on the measurement of a hybridization gap in URu2Si2 employing a spectroscopic technique based on quasiparticle scattering. The differential conductance exhibits an asymmetric double-peak structure, a clear signature for a Fano resonance in a Kondo lattice. The hybridization gap opens well above 17.5 K, indicating that it is not the hidden order parameter. Our results put stringent constraints on the origin of the hidden order transition in URu2Si2 and demonstrate that quasiparticle scattering spectroscopy can probe the band renormalizations in a Kondo lattice via detection of a novel type of Fano resonance.

Smooth emergence in men undergoing nasal surgery: the effect site concentration of remifentanil for preventing cough after sevoflurane-balanced anaesthesia.

BACKGROUND: Suppression of cough during emergence after nasal surgery is practical to avoid bleeding from the surgical site. Previously recommended effect-site concentration of remifentanil for preventing cough during emergence is restricted to female patients undergoing thyroid surgery, so we evaluated effective effect-site concentration of remifentanil for preventing cough during emergence for men undergoing nasal surgery. METHODS: Twenty-four American Society of Anesthesiologists (ASA) physical status I or II, between the ages of 18 and 60 years old, non-smoker male patients undergoing nasal surgery were enrolled in this study. The effective effect-site concentration for 50% of patients (EC(50) ) and and that for 95% of patients (EC(95) ) of remifentanil for preventing cough were determined by Dixon's up-and-down method and by isotonic regression method with a bootstrapping approach. Haemodynamic variables were compared in patients with cough and without cough during emergence. RESULTS: The EC(50) of remifentanil for preventing cough during emergence by Dixon's method was 2.17 ng/ml [standard deviation (SD) 0.38]. The estimated EC(50) and EC(95) of remifentanil using isotonic regression model with a bootstrapping approach were 2.35 ng/ml [95% confidence interval (CI) 1.89-2.66] and 2.94 ng/ml (95% CI 2.83-2.97), respectively. Mean arterial pressure and heart rate were significantly higher in patients with cough during emergence. Three out of 13 patients that received more than 2.5 ng/ml of remifentanil experienced a brief episode of bradypnea. CONCLUSIONS: The EC(95) of remifentanil for preventing cough in men after nasal surgery is 2.94 ng/ml. Remifentanil target-controlled infusion with established effect-site concentration could suppress cough in men during emergence from sevoflurane anaesthesia after nasal surgery, though reversible respiratory depression might arise at high effect-site concentration of remifentanil.

Decline in extractable antibiotics in manure-based composts during composting.

A wide variety of antibiotics have been detected in natural water samples and this is of potential concern because of the adverse environmental effects of such antibiotic residues. One of the main sources of antibiotics effluence to the surrounding environment is livestock manures which often contain elevated concentrations of veterinary antibiotics (VAs) which survive digestion in the animal stomach following application in animal husbandry practices. In Korea, livestock manures are normally used for compost production indicating that there is potential for antibiotic release to the environment through compost application to agricultural lands. Therefore, reduction of the amount of VAs in composts is crucial. The purpose of this study was to understand the influence of the composting process and the components of the compost on the levels of three common classes of antibiotics (tetracyclines, sulfonamides, and macrolides). Composted materials at different stages of composting were collected from compost manufacturing plants and the variation in antibiotic concentrations was determined. Three different antibiotics, chlortetracycline (CTC), sulfamethazine (SMZ), and tylosin (TYL) at three different concentrations (2, 10, and 20mgkg(-1)) were also applied to a mixture of pig manure and sawdust and the mixtures incubated using a laboratory scale composting apparatus to monitor the changes in antibiotic concentrations during composting together with the physicochemical properties of the composts. During composting, in both field and lab-scale investigations, the concentrations of all three different antibiotics declined below the relevant Korean guideline values (0.8mgkg(-1) for tetracyclines, 0.2mgkg(-1) for sulfonamides and 1.0mgkg(-1) for macrolides). The decline of tetracycline and sulfonamide concentrations was highly dependent on the presence of sawdust while there was no influence of sawdust on TYL decline.

Comparison between the SCL-90-R and MMPI in TMD patients with psychological problems.

OBJECTIVE: The aim of the study was to investigate the relationships between the Symptom Checklist-90-Revision (SCL-90-R) and the Minnesota Multiphasic Personality Inventory (MMPI) in temporomandibular disorders (TMD) patients with psychological problems. MATERIALS AND METHODS: Subjective symptoms, objective signs, and psychological characteristics of 36 TMD patients with psychological problems were analyzed. The symptom severity index (SSI) and craniomandibular index (CMI) were used to assess subjective symptoms and objective signs of patients with TMD, respectively. The SCL-90-R and MMPI were used for psychological evaluation. RESULTS: The SSI was not significantly correlated with the CMI in TMD patients with psychological problems, and these indices displayed significant correlations with the SCL-90-R and MMPI in several selected subscales. The results of SCL-90-R had a limited relationship with those of MMPI in these patients. Based on the MMPI diagnosis, the SCL-90-R somatization subscale showed moderate to high sensitivity and specificity, but the SCL-90-R depression subscale showed moderate to low sensitivity and specificity. CONCLUSIONS: Considering the limited relationship between the SCL-90-R and MMPI in TMD patients with psychological problems, more comprehensive psychological tests are recommended when clinicians suspect patients with TMD of having accompanying psychological problems.

The unusual γ-ray burst GRB 101225A from a helium star/neutron star merger at redshift 0.33.

Long γ-ray bursts (GRBs) are the most dramatic examples of massive stellar deaths, often associated with supernovae. They release ultra-relativistic jets, which produce non-thermal emission through synchrotron radiation as they interact with the surrounding medium. Here we report observations of the unusual GRB 101225A. Its γ-ray emission was exceptionally long-lived and was followed by a bright X-ray transient with a hot thermal component and an unusual optical counterpart. During the first 10 days, the optical emission evolved as an expanding, cooling black body, after which an additional component, consistent with a faint supernova, emerged. We estimate its redshift to be z = 0.33 by fitting the spectral-energy distribution and light curve of the optical emission with a GRB-supernova template. Deep optical observations may have revealed a faint, unresolved host galaxy. Our proposed progenitor is a merger of a helium star with a neutron star that underwent a common envelope phase, expelling its hydrogen envelope. The resulting explosion created a GRB-like jet which became thermalized by interacting with the dense, previously ejected material, thus creating the observed black body, until finally the emission from the supernova dominated. An alternative explanation is a minor body falling onto a neutron star in the Galaxy.

Relativistic jet activity from the tidal disruption of a star by a massive black hole.

Supermassive black holes have powerful gravitational fields with strong gradients that can destroy stars that get too close, producing a bright flare in ultraviolet and X-ray spectral regions from stellar debris that forms an accretion disk around the black hole. The aftermath of this process may have been seen several times over the past two decades in the form of sparsely sampled, slowly fading emission from distant galaxies, but the onset of the stellar disruption event has not hitherto been observed. Here we report observations of a bright X-ray flare from the extragalactic transient Swift J164449.3+573451. This source increased in brightness in the X-ray band by a factor of at least 10,000 since 1990 and by a factor of at least 100 since early 2010. We conclude that we have captured the onset of relativistic jet activity from a supermassive black hole. A companion paper comes to similar conclusions on the basis of radio observations. This event is probably due to the tidal disruption of a star falling into a supermassive black hole, but the detailed behaviour differs from current theoretical models of such events.

Intra-operative warming with a forced-air warmer in preventing hypothermia after tourniquet deflation in elderly patients.

This randomized, single-blind study aimed to explore the effects of intra-operative warming with a forced-air warmer in the prevention of hypothermia after tourniquet deflation in elderly patients undergoing unilateral total knee replacement arthroplasty under general anaesthesia. Patients were randomized to receive either intra-operative warming using a forced-air warmer with an upper body blanket (warming group; n = 12) or no intra-operative warming (nonwarming group; n = 12). Oesophageal temperature was measured as core body temperature. At 30 min following tourniquet inflation, the core body temperature started to increase in the warming group whereas it continued to drop in the non-warming group. This difference was statistically significant. The final core body temperature after tourniquet deflation was significantly higher in the warming group (mean +/- SD 36.1 +/- 0.2 degrees C) than in the non-warming group (35.4 +/- 0.3 degrees C). Intra-operative forced-air warming increased the core body temperature before tourniquet deflation and prevented subsequent hypothermia in elderly patients under general anaesthesia.

Phosphodiesterase inhibition by naloxone augments the inotropic actions of beta-adrenergic stimulation.

BACKGROUND: In a shock state, naloxone generates the cardiovascular pressor effect by displacing the endogenous opiate-like peptide beta-endorphin, resulting in restoration of the normal response to catecholamines. In addition to this opioid antagonistic effect, the non-opiate receptor-mediated effect has also been proposed. The aim of this study was to define the mechanism of non-opiate receptor-mediated action of naloxone. METHODS: In guinea-pig ventricular tissues, cumulative concentration-response curves for isoproterenol as well as for forskolin and 3-isobutylmethylxanthine (IBMX) were obtained by increasing the concentration stepwise. To assess the effect on the phosphodiesterase (PDE), the effects of naloxone on contractile forces induced by isoproterenol (0.05 microM) in the presence of IBMX, cilostamide (a PDE III inhibitor), or rolipram (a PDE IV inhibitor) were observed. Naloxone-induced changes in cAMP production by isoproterenol both in the absence and in the presence of IBMX were measured. Naloxone-induced changes in cAMP production by forskolin in the presence of IBMX were also measured. RESULTS: Naloxone (30 microM) produced a leftward shift of the isoproterenol concentration-response curve (0.01-2 microM) without changing the maximal response. Forskolin (0.5-10 microM) produced a concentration-dependent increase in contractile forces. Naloxone increased the maximal inotropic response of forskolin. Naloxone showed no effect on the IBMX concentration-response curve. In the presence of IBMX (200 microM), naloxone did not alter the contractions evoked by isoproterenol or forskolin. Whereas naloxone increased contractile forces significantly (approximately 25%) more than that of isoproterenol in the presence of rolipram, no alteration of contractile forces in the cilostamide-incubated muscles was observed. Naloxone caused a concentration-related increase of cAMP in the absence of IBMX, but caused no change in its presence. CONCLUSIONS: The enhancement of myocardial contractility by naloxone in the presence of stimulation of adenylyl cyclase activity appears to be mediated by inhibition of PDE, specifically PDE III.

Andreev reflection and order parameter symmetry in heavy-fermion superconductors: the case of CeCoIn(5).

We review the current status of Andreev reflection spectroscopy on the heavy fermions, mostly focusing on the case of CeCoIn(5), a heavy-fermion superconductor with a critical temperature of 2.3 K. This is a well-established technique to investigate superconducting order parameters via measurements of the differential conductance from nanoscale metallic junctions. Andreev reflection is clearly observed in CeCoIn(5) as in other heavy-fermion superconductors. Considering the large mismatch in Fermi velocities, this observation seemingly appears to disagree with the Blonder-Tinkham-Klapwijk (BTK) theory. The measured Andreev signal is highly reduced to the order of maximum ∼13% compared to the theoretically predicted value (100%). The background conductance exhibits a systematic evolution in its asymmetry over a wide temperature range from above the heavy-fermion coherence temperature down to well below the superconducting transition temperature. Analysis of the conductance spectra using the extended BTK model provides a qualitative measure for the superconducting order parameter symmetry, which is determined to be the d(x(2)-y(2)) wave in CeCoIn(5). It is found that existing models do not quantitatively account for the data, which we attribute to the intrinsic properties of the heavy fermions. A substantial body of experimental data and extensive theoretical analysis point to the existence of two-fluid components in CeCoIn(5) and other heavy-fermion compounds. A phenomenological model is proposed employing a Fano interference effect between two conductance channels in order to explain both the conductance asymmetry and the reduced Andreev signal. This model appears plausible not only because it provides good fits to the data but also because it is highly likely that the electrical conduction occurs via two channels, one into the heavy-electron liquid and the other into the conduction electron continuum. Further experimental and theoretical investigations will shed new light on the mechanism of how the coherent heavy-electron liquid emerges out of the Kondo lattice, a prototypical strongly correlated electron system. Unresolved issues and future directions are also discussed.

Andreev reflection in heavy-fermion superconductors and order parameter symmetry in CeCoIn5.

Differential conductance spectra are obtained from nanoscale junctions on the heavy-fermion superconductor CeCoIn5 along three major crystallographic orientations. Consistency and reproducibility of characteristic features among the junctions ensure their spectroscopic nature. All junctions show a similar conductance asymmetry and Andreev reflectionlike conductance with a reduced signal ( approximately 10%-13%), both commonly observed in heavy-fermion superconductor junctions. Analysis using the extended Blonder-Tinkham-Klapwijk model indicates that our data provide the first spectroscopic evidence for d_{x;{2}-y;{2}} symmetry. To quantify our conductance spectra, we propose a model by considering the general phenomenology in heavy fermions, the two-fluid behavior, and an energy-dependent density of states. Our model fits to the experimental data remarkably well and should invigorate further investigations.

Comparison of canine single and sequential bilateral lung transplant model for lung preservation study.

The purpose of this study was to compare canine sequential bilateral lung transplantation (SBLT) with left single lung transplant (LSLT) models. After 24 hours of lung preservation with low potassium/dextran glucose (LPDG) solution, seven SBLT procedures were performed using mongrel dogs. The comparative group including nine cases of LSLT. After completion of each transplant, the dogs were maintained on a ventilator for 3 hours. Thereafter serial hemodynamics were evaluated with recipients with chest X-ray, computed tomography, and lung perfusion scan checked at 2 hours after transplantation. Pathological evaluations were also performed. Five of seven SBLT successfully completed the whole assessment, all LSLT survived. In SBLT, pulmonary arterial pressure and pulmonary vascular resistance were significantly elevated, but recovered 3 hours after reperfusion. The ultrastructural aspects of alveolae and pulmonary artery endothelium showed a reversible mild injury 24 hours after lung preservation and reperfusion. The present study suggests that the canine SBLT model using LPDG solution provides an excellent preservation effect and is more physiological as the dog is completely dependent on the function of the transplanted lung.

Integrated biological and electro-chemical treatment of swine manure.

A full-scale biogas plant was applied to the processing of 10 m3/d of swine manure. The plant consisted of an anaerobic digester and an engine-generator. The digester operation resulted in an 81% of COD removal, a 55% of VS reduction, and methane-rich biogas production that is used to generate electrical and thermal energies. To further treat the digested manure, for compliance with discharge limits, an electro-chemical oxidation with a dimensionally sable anode was investigated for the simultaneous elimination of both the remaining COD and ammonia nitrogen. It was able to reduce NH4+-N levels from as high as 1552 down to 25 mg/L in 160 min, and the COD from 1542 to 0.21 mg/L under the experimental conditions of 8 V, 30 A and 20,000 microS/cm. The amount of electricity required for a 90% removal of the residual COD and ammonia in 1 m3 of filtered digester manure, via electrochemical oxidation, were approximately 153 and 151 kWh, respectively. These values exceed the maximum potential capacity of the biogas-originated electricity through the digestion of swine manure containing normal VS content. However, approximately 50% of the required electricity for the electrochemical oxidation could be supplied from the engine-generator.

Chemical libraries towards protein kinase inhibitors.

Over 500 human protein kinases identified to date are susceptible to play crucial roles in the regulation of many signal transduction pathways, making them significant drug discovery targets. However, their active sites share a high level of similarity, which constitutes a major challenge in the finding of selective and safe inhibitors. In order to meet this challenge, whether via traditional or alternative approaches, the use of chemical libraries to find either unknown natural ligands or specific inhibitors of particular kinases is more important than ever. This review briefly summarizes the recent literature on such libraries of peptides, natural product analogues, and small molecules. Significant chemical scaffolds, some synthetic routes particularly on solid-phase support, and computational tools employed for the efficient design of both selective and bioavailable inhibitors are highlighted.

Cocaine administered into the medial prefrontal cortex reinstates cocaine-seeking behavior by increasing AMPA receptor-mediated glutamate transmission in the nucleus accumbens.

One of the major determinants of reinstatement to cocaine use among human addicts is acute reexposure to the drug, which often precipitates cocaine craving and relapse. We used an animal model of cocaine relapse to determine the role of the glutamatergic pathway from the medial prefrontal cortex (mPFC) to the nucleus accumbens in the reinstatement of cocaine-seeking behavior after a cocaine priming injection. Rats were trained to self-administer cocaine intravenously on a second order schedule. Responding was extinguished subsequently by substituting saline for cocaine. During subsequent reinstatement sessions, drug-seeking behavior was assessed after noncontingent priming injections. Results indicated that reinstatement induced by a systemic cocaine injection was blocked by intra-mPFC administration of the dopamine antagonist flupenthixol. Consistent with this finding, administration of cocaine directly into the mPFC reinstated cocaine-seeking behavior. Administration of cocaine into the nucleus accumbens also reinstated drug seeking, whereas microinjection of cocaine into the neostriatum or lateral septum did not. Reinstatement of cocaine seeking induced by intra-mPFC cocaine was blocked by administration of the AMPA receptor antagonist CNQX into the nucleus accumbens. Administration of the NMDA receptor antagonist AP-5 into the nucleus accumbens had variable effects on reinstatement induced by intra-mPFC cocaine in that AP-5 had no effect in some animals but augmented reinstatement in others. Subsequent experiments showed that intra-accumbal microinjection of AP-5 alone dose-dependently reinstated cocaine seeking. These data indicate that the glutamatergic pathway from the mPFC to the nucleus accumbens plays an important role in cocaine priming-induced reinstatement of drug seeking. Moreover, the present results demonstrate that AMPA and NMDA receptors in the nucleus accumbens have opposing roles in the reinstatement of cocaine-seeking behavior.