Levobupivacaine for postoperative epidural analgesia in orthopaedic surgery

INTRODUCTION

Levobupivacaine is the S(-)enantiomer of bupivacaine, a long acting amino-ester local anaesthetic agent. Cocktail mixture of levobupivacaine and fentanyl infusion is commonly given via epidural for post-operative analgesia. The concentration of levobupivacaine for optimal pain relief with least side effects remained uncertain.

MATERIALS AND METHODS

This was a prospective, randomized double-blind study to evaluate the effectiveness and safety of two different concentrations of levobupivacaine as epidural infusion for postoperative pain relief. Fifty patients who underwent orthopaedic lower limb surgeries were recruited and given a standardized combined spinal epidural anaesthesia during operation. They were then allocated to receive either 0.1% (Group A) or 0.2% levobupivacaine (Group B) with 2 Mi g/ml fentanyl as epidural infusion for postoperative pain relief over 24 hours. Pain score, motor blockade, hemodynamic parameters and the need for rescue analgesia were recorded.

RESULTS

Group B patients had significant lower pain score at 4 and 8 hours post operation. There was no significant difference in degree of motor blockade and need for rescue analgesia in both groups. However, patients from Group B had significant hypotension (24% vs 4%) that responded to volume resuscitation without life-threatening complications.

CONCLUSION

0.2% levobupivacaine with 2 Mi g/ml fentanyl provided more superior analgesia compared to 0.1% levobupivacaine with 2 Mi g/ ml fentanyl in patients who underwent lower limb orthopaedic surgery, but with a significant higher incidence of hypotension that responded to volume replacement.

Azimuthal reorientation of pentacene upon 2D condensation

We report a novel two-dimensional gas-solid phase transition of pentacene molecules on the Cu(110)-(2 × 1)O surface where the 2D condensation is accompanied by a reversible azimuthal rotation of the pentacene molecules. The change of the optical anisotropy associated with this reorientation allows us to explore the 2D condensation as a function of coverage and temperature by reflectance difference spectroscopy. As a result, the 2D heat of condensation of pentacene on Cu(110)-(2 × 1)O is determined to be 84 meV, which is more than one order of magnitude smaller than the respective value for 3D crystallization.

Sonographic demonstration of human small intestinal migrating motor complex phase III

BACKGROUND

Migrating motor complex phase III (MMC phase III) of intestine is an important physiological mechanism traditionally recognized by myoelectric recordings or pressure tracings. Direct imaging is difficult and sonographic visualization in human has not been reported.

METHODS

We have demonstrated this unique phenomenon in three patients who underwent abdominal sonographic examinations. Characteristic images were recorded by videotape and both spatial and temporal features were analyzed.

KEY RESULTS

Occurrences of multiple equally spaced, rhythmic intestinal contractions were observed. Parameters including wave frequency, propagation velocity, and duration of the events agreed with those of the well-known phase III. The presence of distinct cyclic patterns observed in two and abolition by meal in the other patient further support our conclusion.

CONCLUSIONS & INFERENCES

We conclude that the migrating waves observed in our study represent the human MMC phase III. This unique finding in human subjects merits further investigation.

Decoupling free-carriers contributions from oxygen-vacancy and cation-substitution in extrinsic conducting oxides

The intrinsic oxygen-vacancies and the extrinsic dopants are two major fundamental free-carrier sources for the extrinsic conducting oxides, such as Sn-doped In(2)O(3). Yet, the individual contributions of the above two free-carrier sources to the total carrier concentrations have never been unraveled. A carrier-concentration separation model is derived in this work, which can define the individual contributions to the total carrier concentration from the intrinsic oxygen-vacancies and the extrinsic dopants, separately. The individual contributions obtained from the present carrier-concentration separation model are verified by the two-state trapping model, photoluminescence, and positron annihilation lifetime (PAL) spectroscopy. In addition, the oxygen-vacancy formation energy of the Sn:In(2)O(3) thin film is determined to be 0.25 eV by PAL spectroscopy.

Observation of two new N* resonances in the decay ψ(3686)→ppπ0

Based on 106×10(6)ψ(3686) events collected with the BESIII detector at the BEPCII facility, a partial wave analysis of ψ(3686)→ppπ0 is performed. The branching fraction of this channel has been determined to be B(ψ(3686)→ppπ0)=(1.65±0.03±0.15)×10(-4). In this decay, 7 N* intermediate resonances are observed. Among these, two new resonances, N(2300) and N(2570) are significant, one 1/2+ resonance with a mass of 2300(-30-0)(+40+109)  MeV/c2 and width of 340(-30-58)(+30+110)  MeV/c2, and one 5/2- resonance with a mass of 2570(-10-10)(+19+34)  MeV/c2 and width of 250(-24-21)(+14+69)  MeV/c2. For the remaining 5 N* intermediate resonances [N(1440), N(1520), N(1535), N(1650) and N(1720)], the analysis yields mass and width values that are consistent with those from established resonances.

Social behaviour risk factors for drug resistant tuberculosis in mainland China: a meta-analysis

OBJECTIVE

To determine risk factors associated with drug resistant tuberculosis (TB) in mainland China.

METHODS

PubMed and Chinese BioMedical databases were searched. Cohort, case-control and cross-sectional studies providing effect estimates of risk factors for any-drug resistant or multidrug resistant (MDR) TB were included.

RESULTS

The meta-analysis included 16 studies. Any-drug resistant TB was significantly associated with poor quality directly observed treatment, shortcourse (DOTS) (odds ratio [OR] 2.65, 95% confidence interval [CI] 1.22, 5.79), long term illness > 1 year (OR 2.71, 95% CI 1.34, 5.48), poor treatment adherence (OR 2.00, 95% CI 1.17, 3.40), previous treatment (OR 4.54, 95% CI 2.71, 7.61) and age 40 - 60 years (OR 1.62, 95% CI 1.10, 2.38). MDR-TB was significantly associated with poor quality DOTS (OR 1.84, 95% CI 1.36, 2.49), poor treatment adherence (OR 4.39, 95% CI 2.97, 6.50), previous treatment (OR 3.83, 95% CI 2.12, 6.89) and poverty (OR 1.87, 95% CI 1.38, 2.52).

CONCLUSIONS

Previous treatment, poor quality DOTS, poor treatment adherence, long term illness, age 40 - 60 years and poverty are associated with a greater risk of drug resistant TB in mainland China.

Evidence for the direct two-photon transition from ψ(3686) to J/ψ

The two-photon transition ψ(3686)→γγJ/ψ is studied in a sample of 1.06×10(8) ψ(3686) decays collected by the BESIII detector. The branching fraction is measured to be (3.1±0.6(stat)(-1.0)(+0.8)(syst))×10(-4) using J/ψ→e(+)e(-) and J/ψ→μ(+)μ(-) decays, and its upper limit is estimated to be 4.5×10(-4) at the 90% confidence level. This work represents the first measurement of a two-photon transition among charmonium states. The orientation of the ψ(3686) decay plane and the J/ψ polarization in this decay are also studied. In addition, the product branching fractions of sequential E1 transitions ψ(3686)→γχ(cJ) and χ(cJ)→γJ/ψ(J=0,1,2) are reported.

Electromagnetic scanning to estimate carcass lean content of Taiwan native broilers

To estimate lean content of Taiwan native broiler carcasses accurately, objectively and rapidly, electrical conductivity measurements of broiler carcasses and other relative factors (carcass weight, length and temperature) were used in multiple linear regression analysis for lean prediction. Forty native broiler carcasses, with average market weight 2477.5±465.5 g, were scanned through a 10 MHz electromagnetic field created by an electromagnetic scanner (SA-3203) to measure the total body electrical conductivity (TOBEC) index. After scanning, each broiler carcass was separated into wing, breast, leg and back. Each primal cut was dissected into lean, fat and bone. The weight, length, temperature and TOBEC index of broiler carcass were significantly correlated with lean weight of broiler carcass (P<0.001). Regression analysis for lean estimation with carcass weight, length, temperature and TOBEC index showed higher coefficient of determination (R(2)=0.968) and lower coefficient of variation (CV=4.178) with an equation using beheaded carcass weight, temperature and TOBEC index as variables.

Metabotropic glutamate receptor 5 antagonist 2-methyl-6-(phenylethynyl)pyridine produces antidepressant effects in rats: role of brain-derived neurotrophic factor

Recent studies highlight that the brain glutamate system is involved in the etiology of depression and glutamatergic-targeting drugs are currently being explored as novel antidepressant medications. Previous studies reveal that the selective metabotropic glutamate receptor 5 antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP) produces antidepressant-like effects in behavioral despair and olfactory bulbectomy models. The current study aimed to further explore its behavioral actions in additional animal models of depression (forced swimming test (FST) and learned helplessness (LH) test) and its underlying neurobiological mechanisms. The results demonstrated that acute treatment of MPEP at 30 but not 10mg/kg significantly reduced immobility in FST without affecting locomotor activities. Sub-chronic, five-day treatment of MPEP (30 mg/kg) decreased escape failures in animals that had developed LH symptoms. This sub-chronic treatment also increased hippocampal brain-derived neurotrophic factor (BDNF) protein levels in both non-stressed and stressed animals and restored the stress-induced down-regulation of BDNF expression. Current findings provide strong evidence for further studies of MPEP as a tool to explore novel antidepressants.

First observation of the M1 transition ψ(3686)→γη(c)(2S)

Using a sample of 106×10(6) ψ(3686) events collected with the BESIII detector at the BEPCII storage ring, we have made the first measurement of the M1 transition between the radially excited charmonium S-wave spin-triplet and the radially excited S-wave spin-singlet states: ψ(3686)→γη(c)(2S). Analyses of the processes ψ(3686)→γη(c)(2S) with η(c)(2S)→K(S)(0)K(±)π(∓) and K(+)K(-)π(0) give an η(c)(2S) signal with a statistical significance of greater than 10 standard deviations under a wide range of assumptions about the signal and background properties. The data are used to obtain measurements of the η(c)(2S) mass (M(η(c)(2S))=3637.6±2.9(stat)±1.6(syst) MeV/c(2)), width (Γ(η(c)(2S))=16.9±6.4(stat)±4.8(syst) MeV), and the product branching-fraction (B(ψ(3686)→γη(c)(2S))×B(η(c)(2S)→KKπ)=(1.30±0.20(stat)±0.30(syst))×10(-5)). Combining our result with a BABAR measurement of B(η(c)(2S)→KKπ), we find the branching fraction of the M1 transition to be B(ψ(3686)→γη(c)(2S))=(6.8±1.1(stat)±4.5(syst))×10(-4).

Measurements of the mass and width of the η(c) using the decay ψ(3686)→γη(c)

The mass and width of the lowest-lying S-wave spin singlet charmonium state, the η(c), are measured using a data sample of 1.06×10(8) ψ(3686) decays collected with the BESIII detector at the BEPCII storage ring. We use a model that incorporates full interference between the signal reaction, ψ(3686)→γη(c), and a nonresonant radiative background to describe the line shape of the η(c) successfully. We measure the η(c) mass to be 2984.3±0.6±0.6 MeV/c(2) and the total width to be 32.0±1.2±1.0 MeV, where the first errors are statistical and the second are systematic.

First observation of η(1405) decays into f(0)(980)π0

The decays J/ψ → γ π+ π- π0 and J/ψ → γ π0 π0 π0 are analyzed using a sample of 225×10(6) J/ψ events collected with the BESIII detector. The decay of η(1405) → f(0)(980)π0 with a large isospin violation is observed for the first time. The width of the f(0)(980) observed in the dipion mass spectra is anomalously narrower than the world average. Decay rates for three-pion decays of the η' are also measured precisely.

Spin-parity analysis of pp¯ mass threshold structure in J/ψ and ψ(3686) radiative decays

A partial wave analysis of the pp¯ mass-threshold enhancement in the reaction J/ψ→γpp¯ is used to determine its J(PC) quantum numbers to be 0(-+), its peak mass to be below threshold at M=1832(-5)(+19)(stat)(-17)(+18)(syst)±19(model) MeV/c(2), and its total width to be Γ<76 MeV/c(2) at the 90% C.L. The product of branching ratios is measured to be BR[J/ψ→γX(pp¯)]BR[X(pp¯)→pp¯]=[9.0(-1.1)(+0.4)(stat)(-5.0)(+1.5)(syst)±2.3(model)]×10(-5). A similar analysis performed on ψ(3686)→γpp¯ decays shows, for the first time, the presence of a corresponding enhancement with a production rate relative to that for J/ψ decays of R=[5.08(-0.45)(+0.71)(stat)(-3.58)(+0.67)(syst)±0.12(model)]%.

Thermal Effects and Small Signal Modulation of 1.3-μm InAs/GaAs Self-Assembled Quantum-Dot Lasers

We investigate the influence of thermal effects on the high-speed performance of 1.3-μm InAs/GaAs quantum-dot lasers in a wide temperature range (5-50°C). Ridge waveguide devices with 1.1 mm cavity length exhibit small signal modulation bandwidths of 7.51 GHz at 5°C and 3.98 GHz at 50°C. Temperature-dependent K-factor, differential gain, and gain compression factor are studied. While the intrinsic damping-limited modulation bandwidth is as high as 23 GHz, the actual modulation bandwidth is limited by carrier thermalization under continuous wave operation. Saturation of the resonance frequency was found to be the result of thermal reduction in the differential gain, which may originate from carrier thermalization.

ηπ+ π- resonant structure around 1.8 GeV/c(2) and η(1405) in J/ψ → ωηπ+ π-

We present results of a study of the decay J/ψ → ωηπ+ π- using a sample of (225.2 ± 2.8) × 10(6) J/ψ events collected by the BESIII detector, and report the observation of a new process J/ψ → ωX(1870) with a statistical significance of 7.2σ, in which X(1870) decays to a(0)(±)(980)π±. Fitting to ηπ+ π- mass spectrum yields a mass M = 1877.3 ± 6.3(stat)(-7.4)(+3.4)(syst) MeV/c(2), a width Γ = 57 ± 12(stat)(-4)(+19)(syst) MeV/c(2), and a product branching fraction B(J/ψ → ωX) × B(X→a(0)(±)(980)π±) × B(a(0) (±)(980) → ηπ±) = [1.50 ± 0.26(stat)(-0.36)(+0.72) (syst)] × 10(-4). Signals for J/ψ → ωf(1)(1285) and J/ψ → ω η(1405) are also clearly observed and measured.

Comparison between LMA-Classic and AMBU AuraOnce laryngeal mask airway in patients undergoing elective general anaesthesia with positive pressure ventilation

BACKGROUND

The LMA-Classic laryngeal mask airway (Classic LMA) is an autoclavable and reusable laryngeal mask airway with strong evidence supporting its efficacy and safety. Due to the concern of infection risk particularly of prion disease, various single-use laryngeal mask devices were developed. The Ambu AuraOnce LMA (Ambu LMA) is a single use disposable laryngeal mask airway with special design that conforms better to the anatomy of the airway.

OBJECTIVES

The Ambu LMA was compared to the LMA-Classic Classic LMA in respect to ease of insertion, adequacy of seal intraoperatively and postoperative complications in patients undergoing elective general anaesthesia with positive pressure ventilation.

METHODS

One hundred and eighteen ASA I and II patients undergoing elective general anaesthesia were randomly allocated into receiving either the Ambu LMA or the Classic LMA. The time taken and number of attempts taken to insert the laryngeal mask was recorded. Intra-operative adequacy of seal was assessed via the amount of nitrous oxide leak using a nitrous oxide analyser. Readings were charted at 0, 20, 40 and 60 minutes of operation. Complications postoperatively (blood stains on the device and occurrence of sore throat) were also recorded.

RESULTS

The success of first attempt insertion was comparable between the two groups (Classic LMA 87% versus Ambu LMA 83%). However the time of insertion was significantly shorter in the Ambu LMA group (p = 0.008). Nitrous oxide level was comparable between the two groups up to 20 minutes of operation. At 40 and 60 minutes, the Ambu LMA showed a significant lower nitrous oxide leak compared to the Classic LMA. Postoperatively, incidence of blood stains was comparable between the two groups, however the incidence of sore throat was lower in the Ambu LMA group (p = 0.025).

CONCLUSIONS

This study demonstrated that the Ambu LMA was comparable to the Classic LMA in terms of the ease of insertion, but provided better seal during positive pressure ventilation with less postoperative sore throat.

Observation of χ(c1) decays into vector meson pairs φφ, ωω, and ωφ

Using (106±4)×10⁻⁶ ψ(3686) events accumulated with the BESIII detector at the BEPCII e⁺e⁻ collider, we present the first measurement of decays of χ(c1) to vector meson pairs φφ, ωω, and ωφ. The branching fractions are measured to be (4.4±0.3±0.5)×10⁻⁴, (6.0±0.3±0.7)×10⁻⁴, and (2.2±0.6±0.2)×10⁻⁵, for χ(c1)→φφ, ωω, and ωφ, respectively, which indicates that the hadron helicity selection rule is significantly violated in χ(cJ) decays. In addition, the measurement of χ(cJ)→ωφ provides the first indication of the rate of doubly OZI-suppressed χ(cJ) decay. Finally, we present improved measurements for the branching fractions of χ(c0) and χ(c2) to vector meson pairs.

Infections caused by Gordonia species at a medical centre in Taiwan, 1997 to 2008

The inability of conventional identification systems to accurately identify Gordonia spp. often results in the misdiagnosis of infections by these rare pathogens, which require genomic sequencing for precise identification. In the present study, we describe nine cases of the various types of infection caused by Gordonia spp. From 1997 to 2008, 66 isolates (from 30 patients) initially identified as Rhodoccus spp. by conventional biochemical methods, by the Bacteriology Laboratory of National Taiwan University Hospital, were retrospectively analysed to assess the accuracy of species identification. Fifteen of these isolates (from nine patients) were later found to be Gordonia spp. by two molecular methods: PCR-restriction fragment length polymorphism for heat shock protein gene (hsp65) and the 16S rRNA gene sequencing analysis. Gordonia sputi (n = 8) was the most common species, followed by Gordonia terrae (n = 7). Most of the isolates were isolated from blood (n = 11), followed by soft tissue (n = 2) and eye (n = 2). Five patients presented with bacteraemia and two of these had catheter-related bloodstream infection. Two patients had soft tissue infections and another two patients had infective keratitis and conjunctivitis. The random amplified polymorphic DNA patterns for isolates from different patients were different, indicating that they were genetically unrelated. Accurate identification with molecular methods is required if the role of Gordonia spp. in causing infection is to be recognized.

Spontaneous emission study on 1.3 µm InAs/InGaAs/GaAs quantum dot lasers

True spontaneous emission (TSE) measurements on InAs/InGaAs/GaAs quantum dot (QD) lasers have been performed as a function of injection current and cavity length. For each laser, TSE from both the ground state (GS) transition and the excited state (ES) transition has been analyzed. It is found that Auger processes are the major nonradiative recombination (NR) processes for both the GS and ES transitions. In particular, for the first time, the existence of Auger like NR features in ES transitions has been experimentally demonstrated. In addition, obvious competition for carriers between the ES transition and the GS transition has been observed in TSE analysis. Furthermore, the QD laser's cavity length has a strong effect on the NR process in GS transitions, due to GS gain saturation. Therefore, when analyzing the NR processes in operating QD lasers, gain saturation due to cavity length limits should be properly considered.

Can the use of 70% isopropyl alcohol swab or aspiration using 5 microm Filter Straw reduce bacterial contamination of fentanyl solution used for regional anaesthesia?

This prospective study aimed to determine the extent of contamination of fentanyl solutions used for central neuraxial injection by wiping the neck of the ampoules with 70% isopropyl alcohol swabs (Kendall) before breaking open the ampoules and aspiration of fentanyl solutions using a 5 microm Filter Straw (B. Braun). In Group A, fifty fentanyl ampoules were wiped with 70% isopropyl alcohol swab prior to opening and the contents were aspirated immediately using a 21G needle and a 5 microm filter straw for culture. The same steps were repeated on the remaining solutions after two hours. In Group B, all the above steps were repeated but without wiping the ampoules with 70% isopropyl alcohol swabs. None of the samples from the wiped ampoules or aspiration using filter straw grew microorganisms. Six percent of the samples from unwiped group grew microorganisms when fentanyl were aspirated using a 21G needle and the contamination increased to 16% when repeated after two hours. Wiping the outsides of the fentanyl ampoules with 70% isopropyl alcohol swabs before opening or aspirating the contents using a 5 pm filter straw has been shown to be equally effective in avoiding bacterial contamination and should be practiced routinely when performing regional anaesthesia.

Confirmation of the X(1835) and observation of the resonances X(2120) and X(2370) in J/ψ→γπ+π-η'

With a sample of (225.2±2.8)×10(6) J/ψ events registered in the BESIII detector, J/ψ→γπ(+)π(-)η(') is studied using two η(') decay modes: η(')→π(+)π(-)η and η(')→γρ(0). The X(1835), which was previously observed by BESII, is confirmed with a statistical significance that is larger than 20σ. In addition, in the π(+)π(-)η(') invariant-mass spectrum, the X(2120) and the X(2370), are observed with statistical significances larger than 7.2σ and 6.4σ, respectively. For the X(1835), the angular distribution of the radiative photon is consistent with expectations for a pseudoscalar.

Evidence for ψ' decays into γπ0 and γη

The decays ψ'→γπ(0), γη and γη' are studied using data collected with the BESIII detector at the BEPCII e(+)e(-) collider. The processes ψ'→γπ(0) and ψ'→γη are observed for the first time with signal significances of 4.6σ and 4.3σ, respectively. The branching fractions are determined to be B(ψ'→γπ(0))=(1.58±0.40±0.13)×10(-6), B(ψ'→γη)=(1.38±0.48±0.09)×10(-6), and B(ψ'→γη')=(126±3±8)×10(-6), where the first errors are statistical and the second ones systematic.

Large Seebeck coefficients of protonated titanate nanotubes for high-temperature thermoelectric conversion

Titanate nanotubes Na(2-x)H(x)Ti(3)O(7) produced by alkali hydrothermally treated ground TiO(2) aerogels are investigated as possible materials for high-temperature thermoelectric conversion by measuring their thermoelectric properties. Strikingly, the Seebeck coefficients increased sharply in the temperature range 745 to 1032 K, reaching a maximum of 302 muV/K. The electrical resistivity of the TNNTs ranged from 325 to 525 Omegam, which is lower than that of bulk TiO(2), and thermal conductivities at room temperature were also very low, ranging from 0.55 to 0.75 Wm(-1) K(-1). The hollow structure of the titanate nanotubes, with small, uniform diameters, is thought to be responsible for the ultralow thermal conductivity. The large thermoelectric power and ultralow thermal conductivity suggest that titanate nanotubes represent a new kind of p-type oxide thermoelectric material.