Hydrogen sulfide synthesis enzymes reduced in lower esophageal sphincter of patients with achalasia

The etiology of achalasia remains largely unknown. Considerable evidence reveals that the lower esophageal sphincter dysfunction is due to the lack of inhibitory neurotransmitter, secondary to esophageal neuronal inflammation or loss. Recent studies suggest hydrogen sulfide may act as an inhibitory transmitter in gastrointestinal tract, but study about hydrogen sulfide in human esophagus still lack. The aim of the study was to investigate if hydrogen sulfide synthesis enzymes could be detected in human esophagus and if the synthesis of the endogenous hydrogen sulfide could be affected in achalasia patients. Tissue samples in cardia, lower esophageal sphincter, 2 cm and 4 cm above lower esophageal sphincter were obtained from achalasia patients undergoing peroral endoscopic myotomy. Control tissues in lower esophageal sphincter were obtained from esophageal carcinoma patients. Expression of cystathionine-β-synthase and cystathionine-γ-lyase in lower esophageal sphincter of achalasia patients and control were detected by immunohistochemical staining. In addition, expression of cystathionine-β-synthase and cystathionine-γ-lyase were compared among different parts of esophagus in achalasia patients. Compared with control, the expression of cystathionine-β-synthase and cystathionine-γ-lyase in lower esophageal sphincter of achalasia patients was significantly reduced (χ² = 11.429, P = 0.010). The expression of cystathionine-β-synthase and cystathionine-γ-lyase were lower in lower esophageal sphincter than that in 2 cm and 4 cm above lower esophageal sphincter, respectively (all P < 0.05). In conclusion, the expression of hydrogen sulfide synthesis enzymes, cystathionine-β-synthase and cystathionine-γ-lyase, can be detected in human esophagus and is reduced in patients with achalasia, which implicates the involvement of the two hydrogen sulfide synthesis enzymes in the pathophysiology of achalasia.

Providing Quantitative Feedback When Teaching Tendon Repair: A New Tool

Flexor tendon repair remains one of the more difficult technical tasks facing the hand surgeon. A good repair must be both strong and able to glide smoothly through the tendon sheath. The purpose of this study is to present a model that allows surgeons to improve their technique of flexor tendon repair by receiving feedback on these important biomechanical parameters. The set-up requires testing equipment found in most biomechanical laboratories and should be available in many academic medical centres. Preliminary data suggest that receiving feedback about the strength and smoothness of a flexor tendon repair may be a very useful tool in helping surgeons improve the overall quality of their tendon repair technique.

Different Resistance to UV-B Radiation of Extracellular Polymeric Substances of Two Cyanobacteria from Contrasting Habitats

The effects of UV-B radiation (UVBR) on photosynthetic activity (Fv/Fm) of aquatic Synechocystis sp. and desert Chroococcus minutus and effects on composition and fluorescence property of extracellular polymeric substances (EPSs) from Synechocystis sp. and C. minutus were comparatively investigated. The desert cyanobacterium species C. minutus showed higher tolerance of PSII activity (Fv/Fm) to UVBR than the aquatic Synechocystis sp., and the inhibited PSII activity of C. minutus could be fully recovered while that of Synechocystis sp. could be partly recovered. UVBR had significant effect on the yield and biochemical composition of EPS of both species. Protein-like and humic acid-like substances were detected in EPS from Synechocystis sp., and protein-like and phenol-like fluorescent compounds were detected in EPS from C. minutus. Proteins in EPS of desert and aquatic species were significantly decomposed under UVBR, and the latter was more easily decomposed. The polysaccharides were much more resistant to UVBR than the proteins for both species. Polysaccharides of Synechocystis sp. was degraded slightly but those of C. minutus was little decomposed. The higher tolerance to UVBR of the desert cyanobacterium can be attributed to the higher resistance of its EPS to photodegradation induced by UVBR in comparison with the aquatic species.

Current epidemiological profile and features of traumatic spinal cord injury in Heilongjiang province, Northeast China: implications for monitoring and control

STUDY DESIGN

A retrospective hospital-based study.

OBJECTIVES

Traumatic spinal cord injury (TSCI) is considered to be an important public health problem worldwide. Only a few studies concerning the regional epidemiological characteristics of TSCI have been published in China. The purpose is to evaluate the epidemiological characteristics of TSCI in Heilongjiang province in northeast China.

SETTING

The Second Affiliated Hospital of Harbin Medical University and the Fifth Hospital of Harbin City, Heilongjiang province.

METHODS

Information of 232 patients who suffered from TSCI was gathered from their charts between January 2009 and December 2013. Information on sociodemographic variables was collected from each chart, including the patient's age, sex, occupation, injury time, causes and extent of injury.

RESULTS

The average age of patients with TSCI was 45.35±14.35 years. The male/female ratio was 4:1. The incidence of TSCI increased gradually with age and peaked in the 46- to 60-year-old age category. The most common occupation was farm laborer (35.34%). Motor vehicle collisions, followed by falls, were found to be the leading cause of TSCI. Furthermore, the majority of TSCI patients (76.29%) suffered a cervical injury.

CONCLUSION

The present study reveals that TSCI is an issue in the province, and it should not be ignored. Our results provide preliminary evidence and theoretical basis for developing an integrated control program for TSCI.

Correction: Site controlled red-yellow-green light emitting InGaN quantum discs on nano-tipped GaN rods

Correction for 'Site controlled red-yellow-green light emitting InGaN quantum discs on nano-tipped GaN rods' by M. Conroy et al., Nanoscale, 2016, 8, 11019-11026.

Risk factors and clinical outcomes for carbapenem-resistant Enterobacteriaceae nosocomial infections

This study was aimed to determine the risk factors of Carbapenem-resistant Enterobacteriaceae (CRE) nosocomial infections and assess the clinical outcomes. A case-case-control design was used to compare two groups of case patients with control patients from March 2010 to November 2014 in China. Risk factors for the acquisition of CRE infections and clinical outcomes were analyzed by univariable and multivariable analysis. A total of 94 patients with CRE infections, 93 patients with Carbapenem-susceptible Enterobacteriaceae (CSE) infections, and 93 patients with organisms other than Enterobacteriaceae infections were enrolled in this study. Fifty-five isolates were detected as the carbapenemase gene. KPC-2 was the most common carbapenemase (65.5 %, 36/55), followed by NDM-1 (16.4 %, 9/55), IMP-4 (14.5 %, 8/55), NDM-5 (1.8 %, 1/55), and NDM-7 (1.8 %, 1/55). Multivariable analysis implicated previous use of third or fourth generation cephalosporins (odds ratio [OR], 4.557; 95 % confidence interval [CI], 1.971-10.539; P < 0.001) and carbapenems (OR, 4.058; 95 % CI, 1.753-9.397; P = 0.001) as independent risk factors associated with CRE infection. The in-hospital mortality of the CRE group was 57.4 %. In the population of CRE infection, presence of central venous catheters (OR, 4.464; 95 % CI, 1.332-14.925; P = 0.015) and receipt of immunosuppressors (OR, 7.246; 95 % CI, 1.217-43.478; P = 0.030) were independent risk factors for mortality. Appropriate definitive treatment (OR, 0.339; 95 % CI, 0.120-0.954; P = 0.040) was a protective factor for in-hospital death of CRE infection. Kaplan-Meier curves of the CRE group had the shortest survival time compared with the other two groups. Survival time of patients infected with Enterobacteriaceae with a high meropenem MIC (≥8 mg/L) was shorter than that of patients with a low meropenem MIC (2,4, and ≤ 1 mg/L). In conclusion, CRE nosocomial infections are associated with prior exposure to third or fourth generation cephalosporins and carbapenems. Patients infected with CRE had poor outcome and high mortality, especially high meropenem MIC (≥8 mg/L). Appropriate definitive treatment to CRE infections in the patient is essential.

Characterization of transient noise in Advanced LIGO relevant to gravitational wave signal GW150914

On September 14, 2015, a gravitational wave signal from a coalescing black hole binary system was observed by the Advanced LIGO detectors. This paper describes the transient noise backgrounds used to determine the significance of the event (designated GW150914) and presents the results of investigations into potential correlated or uncorrelated sources of transient noise in the detectors around the time of the event. The detectors were operating nominally at the time of GW150914. We have ruled out environmental influences and non-Gaussian instrument noise at either LIGO detector as the cause of the observed gravitational wave signal.

Xanthotoxin prevents bone loss in ovariectomized mice through the inhibition of RANKL-induced osteoclastogenesis

Xanthotoxin (XAT) is extracted from the seeds of Ammi majus. Here, we reported that XAT has an inhibitory effect on osteoclastogenesis in vitro through the suppression of both receptor activator of nuclear factor-κB ligand (RANKL)-induced ROS generation and Ca(2+) oscillations. In vivo studies showed that XAT treatment decreases the osteoclast number, prevents bone loss, and restores bone strength in ovariectomized mice.

INTRODUCTION

Excessive osteoclast formation and the resultant increase in bone resorption activity are key pathogenic factors of osteoporosis. In the present study, we have investigated the effects of XAT, a natural furanocoumarin, on the RANKL-mediated osteoclastogenesis in vitro and on ovariectomy-mediated bone loss in vivo.

METHODS

Cytotoxicity of XAT was evaluated using bone marrow macrophages (BMMs). Osteoclast differentiation, formation, and fusion were assessed using the tartrate-resistant acid phosphatase (TRAP) stain, the actin cytoskeleton and focal adhesion (FAK) stain, and the fusion assay, respectively. Osteoclastic bone resorption was evaluated using the pit formation assay. Reactive oxygen species (ROS) generation and removal were evaluated using dichlorodihydrofluorescein diacetate (DCFH-DA). Ca(2+) oscillations and their downstream signaling targets were then detected. The ovariectomized (OVX) mouse model was adopted for our in vivo studies.

RESULTS

In vitro assays revealed that XAT inhibited the differentiation, formation, fusion, and bone resorption activity of osteoclasts. The inhibitory effect of XAT on osteoclastogenesis was associated with decreased intracellular ROS generation. XAT treatment also suppressed RANKL-induced Ca(2+) oscillations and the activation of the resultant downstream calcium-CaMKK/PYK2 signaling. Through these two mechanisms, XAT downregulated the key osteoclastogenic factors nuclear factor of activated T cells c1 (NFATc1) and c-FOS. Our in vivo studies showed that XAT treatment decreases the osteoclast number, prevents bone loss, rescues bone microarchitecture, and restores bone strength in OVX mice.

CONCLUSION

Our findings indicate that XAT is protective against ovariectomy-mediated bone loss through the inhibition of RANKL-mediated osteoclastogenesis. Therefore, XAT may be considered to be a new therapeutic candidate for treating osteoporosis.

GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence

We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences. Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5σ. The signal persisted in the LIGO frequency band for approximately 1 s, increasing in frequency and amplitude over about 55 cycles from 35 to 450 Hz, and reached a peak gravitational strain of 3.4_{-0.9}^{+0.7}×10^{-22}. The inferred source-frame initial black hole masses are 14.2_{-3.7}^{+8.3}M_{⊙} and 7.5_{-2.3}^{+2.3}M_{⊙}, and the final black hole mass is 20.8_{-1.7}^{+6.1}M_{⊙}. We find that at least one of the component black holes has spin greater than 0.2. This source is located at a luminosity distance of 440_{-190}^{+180}  Mpc corresponding to a redshift of 0.09_{-0.04}^{+0.03}. All uncertainties define a 90% credible interval. This second gravitational-wave observation provides improved constraints on stellar populations and on deviations from general relativity.

Properties of the Binary Black Hole Merger GW150914

On September 14, 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected a gravitational-wave transient (GW150914); we characterize the properties of the source and its parameters. The data around the time of the event were analyzed coherently across the LIGO network using a suite of accurate waveform models that describe gravitational waves from a compact binary system in general relativity. GW150914 was produced by a nearly equal mass binary black hole of masses 36_{-4}^{+5}M_{⊙} and 29_{-4}^{+4}M_{⊙}; for each parameter we report the median value and the range of the 90% credible interval. The dimensionless spin magnitude of the more massive black hole is bound to be <0.7 (at 90% probability). The luminosity distance to the source is 410_{-180}^{+160}  Mpc, corresponding to a redshift 0.09_{-0.04}^{+0.03} assuming standard cosmology. The source location is constrained to an annulus section of 610  deg^{2}, primarily in the southern hemisphere. The binary merges into a black hole of mass 62_{-4}^{+4}M_{⊙} and spin 0.67_{-0.07}^{+0.05}. This black hole is significantly more massive than any other inferred from electromagnetic observations in the stellar-mass regime.

GW150914: First results from the search for binary black hole coalescence with Advanced LIGO

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) simultaneously observed the binary black hole merger GW150914. We report the results of a matched-filter search using relativistic models of compact-object binaries that recovered GW150914 as the most significant event during the coincident observations between the two LIGO detectors from September 12 to October 20, 2015. GW150914 was observed with a matched filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203000 years, equivalent to a significance greater than 5.1 σ.

GW150914: First results from the search for binary black hole coalescence with Advanced LIGO

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) simultaneously observed the binary black hole merger GW150914. We report the results of a matched-filter search using relativistic models of compact-object binaries that recovered GW150914 as the most significant event during the coincident observations between the two LIGO detectors from September 12 to October 20, 2015. GW150914 was observed with a matched filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203000 years, equivalent to a significance greater than 5.1 σ.

Site controlled red-yellow-green light emitting InGaN quantum discs on nano-tipped GaN rods

We report a method of growing site controlled InGaN multiple quantum discs (QDs) at uniform wafer scale on coalescence free ultra-high density (>80%) nanorod templates by metal organic chemical vapour deposition (MOCVD). The dislocation and coalescence free nature of the GaN space filling nanorod arrays eliminates the well-known emission problems seen in InGaN based visible light sources that these types of crystallographic defects cause. Correlative scanning transmission electron microscopy (STEM), energy-dispersive X-ray (EDX) mapping and cathodoluminescence (CL) hyperspectral imaging illustrates the controlled site selection of the red, yellow and green (RYG) emission at these nano tips. This article reveals that the nanorod tips' broad emission in the RYG visible range is in fact achieved by manipulating the InGaN QD's confinement dimensions, rather than significantly increasing the In%. This article details the easily controlled method of manipulating the QDs dimensions producing high crystal quality InGaN without complicated growth conditions needed for strain relaxation and alloy compositional changes seen for bulk planar GaN templates.

Centrality Dependence of the Charged-Particle Multiplicity Density at Midrapidity in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

The pseudorapidity density of charged particles, dN_{ch}/dη, at midrapidity in Pb-Pb collisions has been measured at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=5.02  TeV. For the 5% most central collisions, we measure a value of 1943±54. The rise in dN_{ch}/dη as a function of sqrt[s_{NN}] is steeper than that observed in proton-proton collisions and follows the trend established by measurements at lower energy. The increase of dN_{ch}/dη as a function of the average number of participant nucleons, ⟨N_{part}⟩, calculated in a Glauber model, is compared with the previous measurement at sqrt[s_{NN}]=2.76  TeV. A constant factor of about 1.2 describes the increase in dN_{ch}/dη from sqrt[s_{NN}]=2.76 to 5.02 TeV for all centrality classes, within the measured range of 0%-80% centrality. The results are also compared to models based on different mechanisms for particle production in nuclear collisions.

Measurement of an Excess in the Yield of J/ψ at Very Low p_{T} in Pb-Pb Collisions at sqrt[s]_{NN}=2.76 TeV

We report on the first measurement of an excess in the yield of J/ψ at very low transverse momentum (p_{T}<0.3  GeV/c) in peripheral hadronic Pb-Pb collisions at sqrt[s_{NN}]=2.76  TeV, performed by ALICE at the CERN LHC. Remarkably, the measured nuclear modification factor of J/ψ in the rapidity range 2.5<y<4 reaches about 7 (2) in the p_{T} range 0-0.3  GeV/c in the 70%-90% (50%-70%) centrality class. The J/ψ production cross section associated with the observed excess is obtained under the hypothesis that coherent photoproduction of J/ψ is the underlying physics mechanism. If confirmed, the observation of J/ψ coherent photoproduction in Pb-Pb collisions at impact parameters smaller than twice the nuclear radius opens new theoretical and experimental challenges and opportunities. In particular, coherent photoproduction accompanying hadronic collisions may provide insight into the dynamics of photoproduction and nuclear reactions, as well as become a novel probe of the quark-gluon plasma.

Tests of General Relativity with GW150914

The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant's mass and spin, as determined from the low-frequency (inspiral) and high-frequency (postinspiral) phases of the signal, are mutually consistent with the binary black-hole solution in general relativity. Furthermore, the data following the peak of GW150914 are consistent with the least-damped quasinormal mode inferred from the mass and spin of the remnant black hole. By using waveform models that allow for parametrized general-relativity violations during the inspiral and merger phases, we perform quantitative tests on the gravitational-wave phase in the dynamical regime and we determine the first empirical bounds on several high-order post-Newtonian coefficients. We constrain the graviton Compton wavelength, assuming that gravitons are dispersed in vacuum in the same way as particles with mass, obtaining a 90%-confidence lower bound of 10^{13}  km. In conclusion, within our statistical uncertainties, we find no evidence for violations of general relativity in the genuinely strong-field regime of gravity.

Longitudinal evaluation of functional connectivity variation in the monkey sensorimotor network induced by spinal cord injury

AIM

Given the unclear pattern of cerebral function reorganization induced by spinal cord injury (SCI), this study aimed to longitudinally evaluate the changes in resting-state functional connectivity (FC) in the sensorimotor network after SCI and explore their relationship with gait performance.

METHODS

Four adult female rhesus monkeys were examined using resting-state functional magnetic resonance imaging during their healthy stage and after hemitransected SCI (4, 8 and 12 weeks after SCI), and the gait characteristics of their hindlimbs were recorded (except 4 weeks after SCI). Twenty sensorimotor-related cortical areas were adopted in the FC analysis to evaluate the functional network reorganization. Correlation analyses were then used to explore the relationship between functional network variations and gait characteristic changes.

RESULTS

Compared with that during the healthy stage, the FC strength during post-SCI period was significantly increased in multiple areas of the motor control network, including the primary sensorimotor cortex, supplementary motor area (SMA) and putamen (Pu). However, the FC strength was remarkably reduced in the thalamus and parieto-occipital association cortex of the sensory network 8 weeks after SCI. Most FC intensities gradually approached the normal level 12 weeks after the SCI. Correlation analyses revealed that the enhanced FC strength between Pu and SMA in the left hemisphere, which regulates motor functions of the right side, was negatively correlated with the gait height of the right hindlimb.

CONCLUSION

The cerebral functional network presents an adjust-recover pattern after SCI, which may help us further understand the cerebral function reorganization after SCI.

Hydrogen-rich gas production via fast pyrolysis of biophysical dried sludge: Effect of particle size and moisture content on product yields and syngas composition

After biophysical drying, a novel biophysical dried sludge particle was obtained. This work aims to investigate the function and effects of particle sizes and moisture contents on the fast pyrolysis of biophysical dried sludge particles. The results showed that large particles (>4 mm) favoured the oil generation with a maximum value of 19.0%, and small particles (<0.27 mm) favoured the char yield with a maximum value of 60.6%. Medium particle fractions (between 0.27 mm and 4 mm) benefited syngas production and induced higher H2 and CO emission, owing to the well-developed microstructure, enrichment of cellulose, and enhanced catalytic effects during the charring process. The introduction of proper moisture content (53.9% to 62.6%) to biophysical dried sludge was found to dramatically enhance syngas yield, hydrogen production, and carbon conversion efficiency. H2 molar concentration reached a maximum of 46.02% at a moisture content of 53.9%, which was attributed to the steam reforming and steam gasification accompanying the initial biophysical dried sludge pyrolysis.