Regulation of neural responses to emotion perception by ketamine in individuals with treatment-resistant major depressive disorder

The glutamate N-methyl-D-aspartate receptor antagonist ketamine has demonstrated antidepressant effects in individuals with treatment-resistant major depressive disorder (TRD) within 24 h of a single dose. The current study utilized functional magnetic resonance imaging (fMRI) and two separate emotion perception tasks to examine the neural effects of ketamine in patients with TRD. One task used happy and neutral facial expressions; the other used sad and neutral facial expressions. Twenty patients with TRD free of concomitant antidepressant medication underwent fMRI at baseline and 24 h following administration of a single intravenous dose of ketamine (0.5 mg kg(-1)). Adequate data were available for 18 patients for each task. Twenty age- and sex-matched healthy volunteers were scanned at one time point for baseline comparison. Whole-brain, voxel-wise analyses were conducted controlling for a family-wise error rate (FWE) of P<0.05. Compared with healthy volunteers, TRD patients showed reduced neural responses to positive faces within the right caudate. Following ketamine, neural responses to positive faces were selectively increased within a similar region of right caudate. Connectivity analyses showed that greater connectivity of the right caudate during positive emotion perception was associated with improvement in depression severity following ketamine. No main effect of group was observed for the sad faces task. Our results indicate that ketamine specifically enhances neural responses to positive emotion within the right caudate in depressed individuals in a pattern that appears to reverse baseline deficits and that connectivity of this region may be important for the antidepressant effects of ketamine.

First Report of Acrostalagmus luteo-albus Causing Red Rust of Needle Mushroom (Flammulina velutipes) in China

Needle mushroom (Flammulina velutipes) is an edible and medicinal mushroom with annual production yields for China exceeding 2 million metric tons. Hebei province is one of the biggest producers of needle mushrooms in China. From 2009 to 2010, red rust-colored sporulation (fungal mycelia and conidia) was found on the substrate surface of white needle mushroom bags in more than 10 mushroom cultivation operations in Hebei. The rust-colored sporulation covered the substrate surface, where the development of the fruiting bodies was inhibited; the stipes were sparse and became light brown when the substrate was slightly affected. The fruiting bodies on severely affected substrate were unable to complete development or shriveled and died off on the substrate. More than 30 to 40% substrate bags were contaminated with the red rust mold, with approximately a 40% yield reduction in each production house. Single conidia were isolated from the red rust mold and cultured on potato dextrose agar at 25°C in the dark. The colony was round, compact, reddish-brown, and slow-growing (2 to 3 mm/d). Main conidiophore axes were erect, often branched in five to seven layers, tapered from the base to the upper part, pale reddish brown at the base, and almost hyaline at the apex. Two to five phialides usually verticillated at each level along the main stipe and its branches. Phialides were narrowly flask-shaped and only very slightly swollen at the base. Conidia were oval, measured 3.5 to 5.4 (4.5) × 2.3 to 3.6 (3.0) μm, L/W = 1.2 to 2.0 (1.5), and formed pale reddish brown, slimy heads. The isolate was tentatively identified as Acrostalagmus luteo-albus based on its morphological characteristics (2). For molecular analysis, the internal transcribed spacer (ITS) regions of ribosomal DNA from the isolate were PCR-amplified using universal primers ITS1 and ITS4. The resulting sequence (Accession No. KC127681) submitted to GenBank had a 99% identity to that of A. luteo-albus (JN545827) isolated from vineyard soil and Accession No. JQ387575 isolated from twig of declining persimmon tree. To confirm the pathogenicity of the isolate to needle mushroom, five bags of needle mushroom with stipes of 1 to 2 cm long were inoculated with a conidia suspension (10⁵ conidia/ml) of the isolate and incubated at 13 to 15°C in the dark, while five non-inoculated bags (sprayed with sterile water only) were used as a control. Five days after inoculation, the development of the fruiting body was obviously inhibited, and a few growing fruiting bodies became light brown, compared with the non-inoculated fruiting bodies, which were growing healthily and fast and were white with no symptoms. The pathogen was re-isolated from the inoculated fruiting bodies. A. luteo-albus is primarily saprophytic but is sometimes pathogenic. Indeed, it has been associated with post-harvest rot of ginger rhizomes in Brazil (1). To our knowledge, this is the first report of A. luteo-albus causing damage to needle mushroom in China. References: (1) S. I. Moreira et al. Trop. Plant Pathol. 38:218, 2013. (2) R. Zare et al. Mycol. Res. 108:576, 2004.

Novel bioactive antimicrobial lignin containing coatings on titanium obtained by electrophoretic deposition

Hydroxyapatite (HAP) is the most suitable biocompatible material for bone implant coatings; its brittleness, however, is a major obstacle, and the reason why research focuses on creating composites with biopolymers. Organosolv lignin (Lig) is used for the production of composite coatings, and these composites were examined in this study. Titanium substrate is a key biomedical material due to its well-known properties, but infections of the implantation site still impose a serious threat. One approach to prevent infection is to improve antimicrobial properties of the coating material. Silver doped hydroxyapatite (Ag/HAP) and HAP coatings on titanium were obtained by an electrophoretic deposition method in order to control deposited coating mass and morphology by varying applied voltage and deposition time. The effect of lignin on microstructure, morphology and thermal behavior of biocomposite coatings was investigated. The results showed that higher lignin concentrations protect the HAP lattice during sintering, improving coating stability. The corrosion stability was evaluated in simulated body fluid (SBF) at 37 °C. Newly formed plate-shaped carbonate-HAP was detected, indicating enhanced bioactive performance. The antimicrobial efficiency of Ag/HAP/Lig was confirmed by its higher reduction of bacteria Staphylococcus aureus TL (S. aureus TL) than of HAP/Lig coating. Cytotoxicity assay revealed that both coatings can be classified as non-toxic against healthy immunocompetent peripheral blood mononuclear cells (PBMC).

Voxel-based approach to generate entire human metacarpal bone with microscopic architecture for finite element analysis

With the development of micro-computed tomography (micro-CT) technology, it is possible to construct three-dimensional (3D) models of human bone without destruction of samples and predict mechanical behavior of bone using finite element analysis (FEA). However, due to large number of elements required for constructing the FE models of entire bone, this demands a substantial computational effort and the analysis usually needs a high level of computer. In this article, a voxel-based approach for generation of FE models of entire bone with microscopic architecture from micro-CT image data is proposed. To enable the FE analyses of entire bone to be run even on a general personal computer, grayscale intensity thresholds were adopted to reduce the amount of elements. Human metacarpal bone (MCP) bone was used as an example for demonstrating the applicability of the proposed method. The micro-CT images of the MCP bone were combined and converted into 3D array of pixels. Dual grayscale intensity threshold parameters were used to distinguish the pixels of bone tissues from those of surrounding soft tissues and improve predictive accuracy for the FE analyses with different sizes of elements. The method of selecting an appropriate value of the second grayscale intensity threshold was also suggested to minimize the area error for the reconstructed cross-sections of a FE structure. Experimental results showed that the entire FE MCP bone with microscopic architecture could be modeled and analyzed on a personal computer with reasonable accuracy.

Efficient high-power terahertz beating in a dual-wavelength synchronously mode-locked laser with dual gain media

We originally present a novel tactic to accomplish a compact efficient dual-wavelength synchronously mode-locked laser by physically combining the Nd:YVO4 crystal to the Nd:GdVO4 crystal as a composite gain medium. With the developed method, the total output power at 1.06 μm could be effectually produced to reach 1.3 W under the optimally balanced two-color intensities. The corresponding mode-locked pulse width and repetition rate are measured to be 47 ps and 2.86 GHz, respectively. Through the optical beating between two carrier frequencies of dual-color synchronous pulses, a train of 0.32 THz ultrashort pulses is further generated with the effective duration of down to 1.6 ps.

Tensile properties of polycaprolactone/nano-CaCO3 composites

The effects of nanometer calcium carbonate content and tensile rate on the tensile properties of the filled polycaprolactone (PCL) composites were investigated. There was a certain reinforcing effect of the filler on the PCL resin. The tensile modulus increased nonlinearly, and the tensile strength also increased with increase of the filler weight fraction. When the filler weight fraction was kept constant, the tensile modulus and tensile strength increased slightly with increasing tensile rates. By comparing the experimental results with those determined from the tensile yield strength theory, the interfacial adhesion between the filler and matrix was found to be relatively strong; it should be one of the reasons for the good reinforcing effect.

High-power tunable single- and multi-wavelength diode-pumped Nd:YAP laser in the (4)F3/2 → (4)I11/2 transition

We experimentally explore the fluorescent spectrum of the Nd:YAP crystal to manifest the feasibility of tunable single- and multi-wavelength operations in the (4)F3/2 → (4)I11/2 transition. An intracavity etalon is subsequently exploited to effectively select spectral lines at 1073, 1080, and 1084 nm with the tunabilities of 0.56, 1.13, and 0.1 nm, respectively. We also experimentally obtain multi-wavelength oscillations among various intermanifold lines in the Nd:YAP crystal with the output powers on the order of several watts for each group. Employing the Cr(4+):YAG crystal to realize the passively Q-switched operation, the maximum average output powers as high as 2.3 and 3.5 W for 1073 and 1080 nm are obtained. The corresponding pulse energies at 1073 and 1080 nm are up to 177 and 159 μJ, respectively.

Efficient high-energy passively Q-switched Nd:YLF/Cr4+:YAG UV laser at 351 nm with pulsed pumping in a nearly hemispherical cavity

We originally utilize a nearly hemispherical cavity to accomplish the energy scale-up for a high-repetition-rate nanosecond pulsed pumped Nd:YLF laser passively Q-switched by the Cr(4+):YAG saturable absorber. This compact laser is able to efficiently generate pulse energy as large as 1.38 mJ and pulse width as short as 5 ns under a pulse repetition rate of 100 Hz. Further employing the developed Nd:YLF laser to perform extracavity harmonic generations, the maximum pulse energies of 490 μJ at 527 nm and 360 μJ at 351 nm are achieved with the shortest pulse duration of 4 ns.

Water-soluble graphene grafted by poly(sodium 4-styrenesulfonate) for enhancement of electric capacitance

Water-soluble poly(sodium 4-styrenesulfonate) modified graphene (PSSS-GR) was successfully synthesized via covalently grafting poly(sodium 4-styrenesulfonate) (PSSS) on the surfaces of graphene (GR) nanosheets. The structure of PSSS-GR was investigated with Fourier transform infrared, x-ray photoelectron and Raman spectroscopy, thermogravimetric analysis, transmission and scanning electron microscopy and atomic force microscopy. The PSSS chains made the GR nanosheets fully exfoliate into a single-layer structure, and the PSSS layer on GR reached 90 wt%. PSSS chains displayed mutually repulsive effects on promoting GR sheets that were more stable in water. The performances of supercapacitors made of PSSS-GR and unmodified GR electrodes were compared using cyclic voltammetry and galvanostatic charge/discharge techniques. The results showed that PSSS is an effective binder for graphene sheets and can increase the specific capacitance of PSSS-GR based supercapacitors and improve their rate capability. The maximum specific capacitance of the PSSS-GR based supercapacitor was 210 F g(-1) at 5 A g(-1), which was 166% higher than for one made of unmodified graphene electrodes. Electrochemical impedance spectroscopy demonstrated fast ion diffusion in the PSSS-GR electrode structure. PSSS-GR based supercapacitors can fulfil one of the essential requirements for potential electric energy storage applications.

Tunable GHz pulse repetition rate operation in high-power TEM(00)-mode Nd:YLF lasers at 1047 nm and 1053 nm with self mode locking

We report on a high-power diode-pumped self-mode-locked Nd:YLF laser with the pulse repetition rate up to several GHz. A novel tactic is developed to efficiently select the output polarization state for achieving the stable TEM(00)-mode self-mode-locked operations at 1053 nm and 1047 nm, respectively. At an incident pump power of 6.93 W and a pulse repetition rate of 2.717 GHz, output powers as high as 2.15 W and 1.35 W are generated for the σ- and π-polarization, respectively. We experimentally find that decreasing the separation between the gain medium and the input mirror not only brings in the pulse shortening thanks to the enhanced effect of the spatial hole burning, but also effectively introduces the effect of the spectral filtering to lead the Nd:YLF laser to be in a second harmonic mode-locked status. Consequently, pulse durations as short as 8 ps and 8.5 ps are obtained at 1053 nm and 1047 nm with a pulse repetition rate of 5.434 GHz.

Parameter optimization for the visco-hyperelastic constitutive model of tendon using FEM

Numerous constitutive models describing the mechanical properties of tendons have been proposed during the past few decades. However, few were widely used owing to the lack of implementation in the general finite element (FE) software, and very few systematic studies have been done on selecting the most appropriate parameters for these constitutive laws. In this work, the visco-hyperelastic constitutive model of the tendon implemented through the use of three-parameter Mooney-Rivlin form and sixty-four-parameter Prony series were firstly analyzed using ANSYS FE software. Afterwards, an integrated optimization scheme was developed by coupling two optimization toolboxes (OPTs) of ANSYS and MATLAB for estimating these unknown constitutive parameters of the tendon. Finally, a group of Sprague-Dawley rat tendons was used to execute experimental and numerical simulation investigation. The simulated results showed good agreement with the experimental data. An important finding revealed that too many Maxwell elements was not necessary for assuring accuracy of the model, which is often neglected in most open literatures. Thus, all these proved that the constitutive parameter optimization scheme was reliable and highly efficient. Furthermore, the approach can be extended to study other tendons or ligaments, as well as any visco-hyperelastic solid materials.

Alterations of white matter tracts following neurotoxic hippocampal lesions in macaque monkeys: a diffusion tensor imaging study

Diffusion tensor imaging (DTI) is a valuable tool for assessing presumptive white matter alterations in human disease and animal models. The current study used DTI to examine the effects of selective neurotoxic lesions of the hippocampus on major white matter tracts and anatomically related brain regions in macaque monkeys. Two years postlesion, structural MRI, and DTI sequences were acquired for each subject. Volumetric assessment revealed a substantial reduction in the size of the hippocampus in experimental subjects, averaging 72% relative to controls, without apparent damage to adjacent regions. DTI images were processed to yield measures of fractional anisotropy (FA), apparent diffusion coefficient (ADC), parallel diffusivity (lADC), and perpendicular diffusivity (tADC), as well as directional color maps. To evaluate potential changes in major projection systems, a region of interest (ROI) analysis was conducted including the corpus callosum, fornix, temporal stem, cingulum bundle, ventromedial prefrontal white matter, and optic radiations. Lesion-related abnormalities in the integrity of the fiber tracts examined were limited to known hippocampal circuitry, including the fornix and ventromedial prefrontal white matter. These findings are consistent with the notion that hippocampal damage results in altered interactions with multiple memory-related brain regions, including portions of the prefrontal cortex.

Determination of Lycopene in Dietary Supplements and Raw Materials by High-Performance Liquid Chromatography: Collaborative Study

A collaborative study was conducted to evaluate the interlaboratory performance of an LC method for lycopene in dietary supplements and the raw materials commonly used in their manufacture. Twelve laboratories from six countries agreed to participate in the study. Results from 10 laboratories were received and are reported. Five dietary supplements, including both tablets and a softgel capsule with a lycopene content ranging from 25 g to 25 mg per unit, and three raw materials, including gelatin-based beadlets, vegetarian beadlets, and a suspension in oil ranging from 5 to 20 lycopene, were analyzed as blind duplicates. In addition to the commercial products, two positive controls and a negative control were included in the study. For the raw materials studied, the repeatability relative standard deviations (RSDr) ranged from 1.49 to 5.13 for total lycopene, and the reproducibility relative standard deviations (RSDR) ranged from 3.84 to 9.21 with HorRat values from 1.23 to 3.24. For finished products, the RSDr ranged from 1.31 to 4.62, RSDR from 4.28 to 10.5, and HorRat values from 0.79 to 2.07. Corresponding values for all-trans-lycopene were significantly higher. It is recommended that the method be considered for Official First Action for all-trans- and total lycopene in finished products and raw materials.

Comments on "Viscoelastic studies of human subscapularis tendon: relaxation test and a Wiechert model" by C. Machiraju, A.V. Phan, A.W. Pearsall, S. Madanagopal, Computer Methods and Programs in Biomedicine (2006)

Referring to the approach for determining the material parameters for a Wiechert model of the human subscapularis tendon proposed by Machiraju et al. [C. Machiraju, A.V. Phan, A.W. Pearsall, S. Madanagopal, Viscoelastic studies of a human subscapularis tendon: relaxation test and a Wiechert model, Computer Methods and Programs in Biomedicine (2006), doi:10.1016/j.cmpb.2006.05.004], some comments are made on the basis of the result of an alternative method that is capable of giving more reasonable values for the Wiechart model with the fitting discrepancies minimized by a multi-variable optimization strategy.

Microsatellite DNA markers for population-genetic studies of blue mackerel (Scomber australasicus) and cross-specific amplification in S. japonicus

Blue mackerel (Scomber australasicus) is targeted by large-scale purse-seiners in the western North Pacific, and its stock structure is still contentious. Herein, we described 10 polymorphic microsatellite loci for blue mackerel. The number of alleles among 32 individuals surveyed ranged from five to 27 (average of 16.2 alleles per locus). Departures from Hardy-Weinberg expectation were observed at two loci. Cross-specific amplification in the congener, S. japonicus, was successful, except for one locus, revealed to be diagnostic for these congeners. These microsatellite loci will be useful tools to address queries in population genetic structure, fishery management unit and taxonomic species status in the genus Scomber.

A feasibility study on laser rapid forming of a complete titanium denture base plate

This work attempted to integrate the technologies of computer-aided design and computer-aided manufacture (CAD/CAM) and laser rapid forming (LRF) for the fabrication of the titanium plate of a complete denture. By the combination of laser scan and reverse engineering software, the standard triangulation language (STL)-formatted denture base plate was finally designed and sliced into a sequence of numerical controlled codes. The titanium (Ti) complete denture plate was finally built, layer-by-layer, on the LRF system. To evaluate the quality of fit, a virtual adaptation test that measured and compared the profiles of the laser free formed denture plate and those of the edentulous plaster cast had been conducted, and the mean deviation was found to be 0.34 mm. After traditional dental finishing techniques, a complete denture with a Ti base plate was then made and judged to be acceptable. The CAD/CAM/LRF system is a potential candidate and a new platform for the design and manufacture of custom-made Ti denture plates and restorations.

Immediate food hypersensitivity among adults attending a clinical immunology/allergy centre in Singapore

INTRODUCTION

The patient characteristics, clinical features and causative foods in 74 consecutive adult patients with immediate food hypersensitivity were studied.

METHODS

A retrospective review of 74 consecutive adults who presented during the study period from July 1, 1994 to April 30, 2002 was performed.

RESULTS

There were 35 male and 39 female patients, with a mean age of 36.3 +/- 10.9 (range, 19-66) years. The most common causative foods were seafood crustaceans, molluscs and bird's nest. Prawn and crab were the most commonly implicated crustacean, and limpet the commonest culprit mollusc. The main symptoms were periorbital angioedema (64.9 percent), dyspnoea/wheezing (44.6 percent) and urticaria (44.6 percent). 66 percent of the patients developed anaphylaxis. 34 (45.9 percent) had concomitant allergic rhinoconjunctivitis, asthma, eczema or combinations of these atopic diseases. Only six (8.1 percent) patients had a family history of food allergy. Skin prick tests (SPT) to commercially-prepared food allergens were positive in 22 of 36 patients (61.1 percent) tested. SPT to the fresh, cooked or canned food products were positive in 11 of 20 (55 percent) cases where the food allergen was not commercially available. Open food challenges were required for diagnosis in two patients who had negative SPT.

CONCLUSION

The most common food allergens in our patients were seafood crustaceans, molluscs and bird's nest. More than half of the patients had concomitant allergic rhinitis, asthma and/or eczema. The pattern of food allergy in Singapore differs from Caucasian populations, likely to be because of different regional dietary patterns and methods of food preparation.

Image deconvolution in spherical aberration-corrected high-resolution transmission electron microscopy

The method of image deconvolution developed previously for FEG high-resolution transmission electron microscope (HRTEM) without a spherical aberration (C(s)) corrector was for the first time applied to FEG HRTEM with a C(s)-corrector. The principle and the procedure of image deconvolution are briefly described. Four qualified [1 1 0] images of Si were selected from a through-focus series to perform image deconvolution. The projected potential is successfully derived from all the images, and the obtained "dumbbell" structure maps of Si [1 1 0] are in good agreement with the calculated potential map. The criterion of selecting qualified images for performing image deconvolution is indicated. The possibility of applying image deconvolution to defect study and to ab initio crystal structure determination is discussed.

Anaphylaxis in adults referred to a clinical immunology/allergy centre in Singapore

INTRODUCTION

To study the clinical features and causes of anaphylaxis in consecutive adult patients referred to a clinical immunology/allergy centre in Singapore.

METHODS

A retrospective review of 67 consecutive adults with anaphylaxis who presented from July 1, 1998 to February 28, 2002 was performed. Anaphylaxis was defined as a severe life-threatening systemic IgE-mediated hypersensitivity reaction. Non-steroidal anti-inflammatory drug-induced idiosyncratic reactions and other non-IgE mediated reactions were excluded. Hypotension and bronchospasm were not required to make a diagnosis. The aetiology was determined from clinical history followed by measurement of allergen-specific IgE levels, skin prick test with commercially-available allergen extracts or prick-prick test with the fresh/cooked/canned food products.

RESULTS

The mean age of patients was 32.9 +/- 10.9 (range 19-57) years. There were 44 (65.7 percent) males and 23 (34.3 percent) females. The main causes were food (44.8 percent), insect stings (32.8 percent) and idiopathic (22.4 percent). There were no cases due to drugs or natural rubber latex. Seafood (crustaceans and molluscs) comprised 66.7 percent of food-induced anaphylaxis. Honeybee and wasp stings together comprised 45 percent of insect venom anaphylaxis. The most common manifestations were dyspnoea (59.7 percent), urticaria (58.2 percent), angioedema (44.8 percent), and syncope (43.3 percent). Hypotension was documented in only 28.4 percent of cases.

CONCLUSION

Food (crustaceans and molluscs) was the most common cause followed by insect stings or bites. The inability to identify the causative insect in 50 percent of cases with insect venom anaphylaxis limited the role of specific immunotherapy. Compared to other reported series, there were no cases of drug or latex anaphylaxis.