Groupwise whole-brain parcellation from resting-state fMRI data for network node identification

In this paper, we present a groupwise graph-theory-based parcellation approach to define nodes for network analysis. The application of network-theory-based analysis to extend the utility of functional MRI has recently received increased attention. Such analyses require first and foremost a reasonable definition of a set of nodes as input to the network analysis. To date many applications have used existing atlases based on cytoarchitecture, task-based fMRI activations, or anatomic delineations. A potential pitfall in using such atlases is that the mean timecourse of a node may not represent any of the constituent timecourses if different functional areas are included within a single node. The proposed approach involves a groupwise optimization that ensures functional homogeneity within each subunit and that these definitions are consistent at the group level. Parcellation reproducibility of each subunit is computed across multiple groups of healthy volunteers and is demonstrated to be high. Issues related to the selection of appropriate number of nodes in the brain are considered. Within typical parameters of fMRI resolution, parcellation results are shown for a total of 100, 200, and 300 subunits. Such parcellations may ultimately serve as a functional atlas for fMRI and as such three atlases at the 100-, 200- and 300-parcellation levels derived from 79 healthy normal volunteers are made freely available online along with tools to interface this atlas with SPM, BioImage Suite and other analysis packages.

An antiapoptotic Bcl-2 family protein index predicts the response of leukaemic cells to the pan-Bcl-2 inhibitor S1

BACKGROUND

Bcl-2-like members have been found to be inherently overexpressed in many types of haematologic malignancies. The small-molecule S1 is a BH3 mimetic and a triple inhibitor of Bcl-2, Mcl-1 and Bcl-XL.

METHODS

The lethal dose 50 (LD(50)) values of S1 in five leukaemic cell lines and 41 newly diagnosed leukaemia samples were tested. The levels of Bcl-2 family members and phosphorylated Bcl-2 were semiquantitatively measured by western blotting. The interactions between Bcl-2 family members were tested by co-immunoprecipitation. The correlation between the LD(50) and expression levels of Bcl-2 family members, alone or in combination, was analysed.

RESULTS

S1 exhibited variable sensitivity with LD(50) values ranging >2 logs in both established and primary leukaemic cells. The ratio of pBcl-2/(Bcl-2+Mcl-1) could predict the S1 response. Furthermore, we demonstrated that pBcl-2 antagonised S1 by sequestering the Bak and Bim proteins that were released from Mcl-1, andpBcl-2/Bak, pBcl-2/Bax and pBcl-2/Bim complexes cannot be disrupted by S1.

CONCLUSION

A predictive index was obtained for the novel BH3 mimetic S1. The shift of proapoptotic proteins from being complexed with Mcl-1 to being complexed with pBcl-2 was revealed for the first time, which is the mechanism underlying the index value described herein.

Catalytic activity of nanocrystalline porous La0.8K0.2Fe(1-x)Mn(x)O3 for simultaneous removal of soot and nitrogen oxides

The nanocrystalline, porous, perovskite La0.8K0.2Fe(1-x)Mn(x)O3 (x = 0-0.5) catalysts were prepared by the citrate-gel process. All the perovskite catalysts can effectively catalyze the soot combustion and among them the La0.8K0.2Fe0.7Mn0.3O3 catalyst exhibits the highest catalytic activity, with a lowest T50 (366 degrees C). This optimized La0.8K0.2Fe0.7Mn0.3O3 catalyst then was coated onto a honeycomb ceramic by the citrate-gel assisted dip-coating method and its catalytic performance was evaluated by the bench test in the practical exhaust emission. It is proved that the La0.8K0.2Fe0.7Mn0.3O3-coated honeycomb ceramic device simultaneously has a effective capture of soot particulates and a good absorption of NO(x) from the exhaust emission at a low temperature and begins to efficiently catalyze oxidization reactions of the soot particulates at around 230 degrees C, and conversion of NO(x) at about 290 degrees C, with a conversion rate of 16.6% at 400 degrees C. This catalytic performance enhancement for simultaneous removal of soot and NO(x) can be largely attributed to the synergistic effect of Fe and Mn, pore structure of a large channel with various small pores connected, and microstructural characteristics of La0.8K0.2Fe0.7Mn0.3O3 catalyst. The catalytic mechanism of capture-oxidation-reduction is rationally proposed.

Porous Cu/Ce-K-O nanocomposites for simultaneous removal of soot and NO(x) from diesel exhaust emission

The porous xCu/(1 - x)Ce-K-O (x = 0.1-0.4) nanocomposites were prepared by the citrate-gel thermal decomposition and reduction process. The effect of nanosized metallic Cu on their microstructure and catalytic properties was investigated by XRD, SEM, BET, TG analysis. With Cu content increasing, the grain size of metallic Cu is increased from 40 nm to 62 nm, whilst the grain size of CeO2 decreases from 38 nm to 20 nm. While, their specific surface area (S(BET)) and average pore size (P(ave)) show an increasing trend with the Cu content increase in the nanocomposites. The catalytic activity for soot combustion is influenced by the Cu content, with a lowest T20 (216 degrees C) and T50 (357 degrees C) for xCu/(1 - x)Ce-K-O (x = 0.3) nanocomposite catalyst. The catalytic performance for the optimal xCu/(1 - x)Ce-K-O (x = 0.3) nanocomposite coated honeycomb ceramic device was evaluated under the practical diesel exhaust emissions at the temperature range of 200-400 degrees C. This 10 wt.% catalyst-loaded honeycomb ceramic device confirms a high catalytic activity and stability for simultaneous removal of soot and NO(x), largely,due to the porous structure and synergistic effect of nano Cu and nano ceria in the catalyst.

Bandwidth enhancement in microwave absorption of binary nanocomposite ferrites hollow microfibers

The binary Ba0.5Sr0.5Fe12O19 (BSFO)/Ni0.5Zn0.5Fe2O4 (NZFO) nanocomposite ferrites hollow microfibers with high aspect ratios have been prepared by the gel precursor transformation process. These microfibers possess a high specific surface area about 45.2 m2 g(-1), and a ratio of the hollow diameter to the fiber diameter estimated about 5/7. The binary nanocomposite ferrites are formed after the precursor calcined at 750 degrees C for 3 h. Their minimum reflection loss (RL) is -38.1 dB at 10.4 GHz. The microwave absorption bandwidth with RL value exceeding -20 dB covers the whole X-band (8.2-12.4 GHz) and Ku-band (12.4-18 GHz). This enhancement in microwave absorption can be attributed to the exchange-coupling interaction, interfacial polarization and small size effect in nanocomposite hollow microfibers.

Adsorption kinetics and isotherms of arsenic(V) from aqueous solution onto Ni0.5Zn0.5Fe2O4 nanoparticles

Magnetic Ni0.5Zn0.5Fe2O4 nanoparticles were synthesized by the facile citrate-gel process. Their morphology, chemical composition, microstructure, and magnetic properties were investigated by XRD, TEM, EDX, BET, and VSM. The as-prepared magnetic Ni0.5Zn0.5Fe2O4 nanoparticles consisting of grains about 20 nm were characterized with specific surface area of 49.0 m2/g and magnetization of 46.1 A m2/kg. The arsenic(V) adsorption onto these magnetic Ni0.5Zn0.5Fe2O4 nanoparticles at room temperature was determined by the ICP-AES measurement of arsenic(V) in aqueous solution. The results show that the pseudo-second-order kinetic model is fitted well to describe the arsenic(V) adsorption process with a determination coefficient (R2 = 0.9862). By comparing with the two- and three-parameter models for adsorption isotherms of arsenic(V) onto the magnetic Ni0.5Zn0.5Fe2O4 nanoparticles at room temperature, the Temkin and Redlich-Peterson model can be used to evaluate the arsenic(V) adsorption isotherm at room temperature. The arsenic(V) equilibrium adsorption quantity is up to 7.2 mg/g for these magnetic Ni0.5Zn0.5Fe2O4 nanoparticles when the initial arsenic(V) concentration is 3 mg/L in aqueous solution.

Radiological and clinical features of adult non-puerperal mastitis

OBJECTIVE

To describe the radiological and clinical features of adult non-puerperal mastitis and to determine the most accurate method of preventing unnecessary surgical procedures.

METHODS

Clinical and imaging findings were retrospectively reviewed in 51 females with non-puerperal mastitis, which was confirmed by biopsy/surgical pathology. All 51 patients had pre-operative MRI; 45 patients also had sonograms and 25 also had mammograms, pre-operatively.

RESULTS

Of the 51 cases with non-puerperal mastitis, 94.1% (48/51) were confirmed as having acute or chronic inflammation, and the other 3 had plasma cell mastitis; areola papillaris inflammation was found in 39.2% (20/51) of the cases. Overall, 6 of the 25 cases that were examined with mammography and 2 of the 45 cases that were examined with sonography appeared normal, but all 51 lesions were positively identified on MRI. Asymmetrical density (12/25) on mammograms and solitary or separated/contiguous, clustered, hypoechoic mass-like lesions (31/45) on ultrasound were the most common signs of non-puerperal mastitis. On enhanced MRI, 90.2% (46/51) of patients showed non-mass-like enhanced lesions. Multiple regional enhancements in the pattern of distribution (32/46) and separated or contiguous, clustered, rim-like enhancements in the pattern of internal enhancement (29/46) were the most common manifestations in non-mass-like enhanced lesions. Of the 51 patients, mastitis Type 1 and Type 2 in the time-signal intensity curve were detected in 47.1% and 51.0% of the patients, respectively. The breast imaging reporting and data system categories with the highest number of patients were Category 0 (9/25) on mammography, Category 4a on sonography (18/45) and Category 4a on MRI (29/51).

CONCLUSION

The findings from mammography and ultrasound are non-specific; therefore, using MR can be helpful in the diagnosis, especially in the presence of non-mass-like enhancements that are multiple, regional, separated, or contiguous, clustered and rim-like.

ADVANCES IN KNOWLEDGE

Mastitis is often neglected because of the lack of typical clinical signs and symptoms. This study has assessed and described the clinical features and imaging findings of adult non-puerperal mastitis on mammograms, sonograms and MRI and found that MRI is more specific in the diagnosis of disease.

Development of a reverse transcription-loop-mediated isothermal amplification (RT-LAMP) system for rapid detection of HDV genotype 1

The object of this study was to develop a reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay for detecting hepatitis D virus (HDV) genotype 1. With an alignment analysis, a highly conserved sequence (nt 820-1020) was chosen as a suitable target to design LAMP primers. The optimal condition of RT-LAMP was a 25-μl reaction volume, which consists of the following components: 1·6 μmol l⁻¹ each of FIP and BIP, 0·2 μmol l⁻¹ each of F3 and B3, 1·5 μmol l⁻¹ dNTPs, 4 mmol l⁻¹ MgSO₄, 8 U Bst DNA polymerase, 2U M-MLV and 2 μl extracted RNA sample. The amplification reaction was carried out at 65°C for 50 min. Compared with conventional qualitative or quantitative real-time reverse transcription polymerase chain reaction, the results of RT-LAMP indicated a 1000-fold increase in sensitivity for detecting HDV. There was no cross-reaction for the RT-LAMP method between HDV 1 and HIV, HAV, HBV, HCV and HEV.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results indicate that RT-LAMP is a simple, rapid, specific, highly sensitive and cost-effective, field-based method for detecting HDV 1. The RT-LAMP assay is an acceptable alternative to diagnose the HDV genotype 1 and to investigate its epidemiology for clinical laboratories lacking specialized equipments.

Structure, thermal stability and electrical properties of reduced graphene/poly(vinylidene fluoride) nanocomposite films

The reduced graphene/poly(vinylidene fluoride) nanocomposite films were prepared by the solution casting-thermal reduction process using graphene oxide (GO) and poly(vinylidene fluoride) (PVDF) resin. With the presence of reduced graphene (RG) nano sheets in the nanocomposite, the structure of PVDF is transformed from alpha to beta phase, and the beta phase fraction and its crystallinity are largely affected by the RG content. The PVDF thermal stability is improved by the RG introduction, with about 15 degrees C increase of the half-life of PVDF decomposition temperature. The RG/PVDF nanocomposites show a better electrical conductivity than that for the GO/PVDF nanocomposites. At a low RG content (0.8 wt.%), the dielectric constant of RG/PVDF nanocomposite film with a very low loss tangent is dramatically increased from about 6 to 23. The mechanisms for the thermal stability and electrical property improvements are discussed.

Tumor suppressor menin mediates peripheral nerve injury-induced neuropathic pain through potentiating synaptic plasticity

Synaptic plasticity is a crucial step in the development of central sensitization in the pathogenesis of neuropathic hyperalgesia. Menin, the product of the multiple endocrine neoplasia type 1 (MEN1) gene, possesses the property of synaptogenesis which plays an essential role in neuronal activity. We tested the contributing role of spinal menin in peripheral nerve injury-induced neuropathic hypersensitivity through modulating neuronal synaptic plasticity. After approval by the Institutional Animal Care and Use Committee, nociceptive responses were detected with von Frey filaments and thermal plate after spared nerve injury in C57BL/6 mice who were treated with either intrathecal antisense oligonucleotide of MEN1 (ASO) or vehicle. Extracellular spontaneous discharge frequency, field excitatory postsynaptic potential (fEPSP), and monosynaptic excitatory postsynaptic currents (EPSCs) were measured electrophysiologically. Intrathecal ASO alleviated nerve injury-induced mechanical and thermal hypersensitivity. Upregulated spinal menin after nerve injury colocalized with NeuN in the superficial laminae; genetic knockdown of spinal menin reduced nerve injury induced in vivo spontaneous activity and instantaneous frequency and in vitro field potentials; ASO decreased the frequency and amplitude of monosynaptic EPSCs, and reduced synaptic strength and total charge. Collectively, these findings highlight the role of upregulated neuronal menin in the spinal cord in potentiating spinal synaptic plasticity in peripheral nerve injury-induced neuropathic hypersensitivity.