Plasmon hybridization in composite nanostructures with tunable resonances and vertex truncation analysis

An Ag/SiO₂/Ag sandwich delta nanostar with three sharp angles (30°) is proposed. The extinction efficiency property with a variation in environment refractive index has been investigated in detail by the finite difference time domain method. The refractive index response sensitivity is 482.67  nm/RIU. And the correlations between resonance wavelengths and thickness of the dielectric layer are also established. It reveals that as the thickness increases, the peak wavelength turns to red shift, and a tunable resonance wavelength is achieved through the thickness adjusting of the SiO₂ layer. The maximum of the electric field enhancement is 833.776 with the thickness of the dielectric layer h=40  nm. Moreover, the influence of the vertex truncation on the extinction spectra and the refractive index sensitivity has also been analyzed.

Allelic differences between Europeans and Chinese for CREB1 SNPs and their implications in gene expression regulation, hippocampal structure and function, and bipolar disorder susceptibility

Bipolar disorder (BD) is a polygenic disorder that shares substantial genetic risk factors with major depressive disorder (MDD). Genetic analyses have reported numerous BD susceptibility genes, while some variants, such as single-nucleotide polymorphisms (SNPs) in CACNA1C have been successfully replicated, many others have not and subsequently their effects on the intermediate phenotypes cannot be verified. Here, we studied the MDD-related gene CREB1 in a set of independent BD sample groups of European ancestry (a total of 64,888 subjects) and identified multiple SNPs significantly associated with BD (the most significant being SNP rs6785[A], P=6.32 × 10(-5), odds ratio (OR)=1.090). Risk SNPs were then subjected to further analyses in healthy Europeans for intermediate phenotypes of BD, including hippocampal volume, hippocampal function and cognitive performance. Our results showed that the risk SNPs were significantly associated with hippocampal volume and hippocampal function, with the risk alleles showing a decreased hippocampal volume and diminished activation of the left hippocampus, adding further evidence for their involvement in BD susceptibility. We also found the risk SNPs were strongly associated with CREB1 expression in lymphoblastoid cells (P<0.005) and the prefrontal cortex (P<1.0 × 10(-6)). Remarkably, population genetic analysis indicated that CREB1 displayed striking differences in allele frequencies between continental populations, and the risk alleles were completely absent in East Asian populations. We demonstrated that the regional prevalence of the CREB1 risk alleles in Europeans is likely caused by genetic hitchhiking due to natural selection acting on a nearby gene. Our results suggest that differential population histories due to natural selection on regional populations may lead to genetic heterogeneity of susceptibility to complex diseases, such as BD, and explain inconsistencies in detecting the genetic markers of these diseases among different ethnic populations.

Neonatal ketamine exposure causes impairment of long-term synaptic plasticity in the anterior cingulate cortex of rats

Ketamine, a dissociative anesthetic most commonly used in many pediatric procedures, has been reported in many animal studies to cause widespread neuroapoptosis in the neonatal brain after exposure in high doses and/or for a prolonged period. This neurodegenerative change occurs most severely in the forebrain including the anterior cingulate cortex (ACC) that is an important brain structure for mediating a variety of cognitive functions. However, it is still unknown whether such apoptotic neurodegeneration early in life would subsequently impair the synaptic plasticity of the ACC later in life. In this study, we performed whole-cell patch-clamp recordings from the ACC brain slices of young adult rats to examine any alterations in long-term synaptic plasticity caused by neonatal ketamine exposure. Ketamine was administered at postnatal day 4-7 (subcutaneous injections, 20mg/kg given six times, once every 2h). At 3-4weeks of age, long-term potentiation (LTP) was induced and recorded by monitoring excitatory postsynaptic currents from ACC slices. We found that the induction of LTP in the ACC was significantly reduced when compared to the control group. The LTP impairment was accompanied by an increase in the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor-mediated excitatory synaptic transmission and a decrease in GABA inhibitory synaptic transmission in neurons of the ACC. Thus, our present findings show that neonatal ketamine exposure causes a significant LTP impairment in the ACC. We suggest that the imbalanced synaptic transmission is likely to contribute to ketamine-induced LTP impairment in the ACC.

Stress-related hormone norepinephrine induces interleukin-6 expression in GES-1 cells

In the current literature, there is evidence that psychological factors can affect the incidence and progression of some cancers. Interleukin 6 (IL-6) is known to be elevated in individuals experiencing chronic stress and is also involved in oncogenesis and cancer progression. However, the precise mechanism of IL-6 induction by the stress-related hormone norepinephrine (NE) is not clear, and, furthermore, there are no reports about the effect of NE on IL-6 expression in gastric epithelial cells. In this study, we examined the effect of NE on IL-6 expression in immortalized human gastric epithelial cells (GES-1 cells). Using real-time PCR and enzyme-linked immunoassay, we demonstrated that NE can induce IL-6 mRNA and protein expression in GES-1 cells. The induction is through the β-adrenergic receptor-cAMP-protein kinase A pathway and mainly at the transcriptional level. Progressive 5'-deletions and site-directed mutagenesis of the parental construct show that, although activating-protein-1 (AP-1), cAMP-responsive element binding protein (CREB), CCAAT-enhancer binding protein-β (C/EBP-β), and nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) binding sites are all required in the basal transcription of IL-6, only AP-1 and CREB binding sites in the IL-6 promoter are required in NE-induced IL-6 expression. The results suggest that chronic stress may increase IL-6 secretion of human gastric epithelial cells, at least in part, by the stress-associated hormone norepinephrine, and provides basic data on stress and gastric cancer progression.

Roles of pyrolysis on availability, species and distribution of Cu and Zn in the swine manure: chemical extractions and high-energy synchrotron analyses

Animal manures generally contain high levels of heavy metals that may pose a significant threat to soil and groundwater qualities. Pyrolysis as means of reducing metal availability in such feed stocks is recently encouraged, but systematic studies are currently lacking. The aim of this study was to assess the impact of pyrolysis temperature on the availability of Cu and Zn by chemical extraction, to determine the speciation of Cu and Zn by synchrotron-based X-ray spectroscopy, and finally to investigate the phase distribution of metal species in the carbonaceous materials by combining acid-base extractions and absorption spectroscopy data. The results showed that both Cu and Zn in the swine manure were mainly bound to organic functional groups. Cu (II) reduction and Cu (I)-S complexes were observed during the pyrolysis process. Zn species resembling ZnAc2 was still dominant, being 60.8-69.2%, and ZnS increased by 6.6-21.8% in the carbonaceous materials. The distribution of Cu and Zn in the mineral, carbonized and non-carbonized organic phases varied greatly with the pyrolysis temperature. The higher the temperature, the more the metals existed in the mineral phase and carbonized organic phase. The decrease of EDTA extractable Cu and Zn with pyrolysis temperature was due to the increase of metals in the carbonized organic phase and mineral phase. It is suggested that pyrolysis at the relatively higher temperature is a better choice for metal-containing manure according to the metal speciation, solubility and availability.

Identification of osteoarthritis biomarkers by proteomic analysis of synovial fluid

OBJECTIVE

To use proteomic analysis to identify novel candidate biomarker proteins in synovial fluid for the differential diagnosis of osteoarthritis and rheumatoid arthritis.

METHODS

Synovial fluid samples were analysed using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Data were used to generate an artificial neural network (ANN). The identification of one protein peak was confirmed via Western blotting.

RESULTS

Fluid samples were analysed from 36 patients with osteoarthritis and 24 with rheumatoid arthritis. In total, three protein peaks (mass-to-charge ratio [m/z] 3893, 10,576 and 14,175 Da) were identified as potential biomarkers for osteoarthritis. The ANN differentiated between osteoarthritis and rheumatoid arthritis with a sensitivity of 89.4% and a specificity of 91.2%. The protein peak at m/z 10 576 was identified as S100 calcium binding protein A12 (S100A12).

CONCLUSIONS

A combination of SELDI-TOF-MS and ANN identified osteoarthritis biomarkers. SELDI-TOF-MS may be a useful tool in the screening of synovial fluid for osteoarthritis diagnosis.

The clinical application of absorbable intramedullary nail and claw plate on treating multiple rib fractures

AIM

The absorption intramedullary nail and claw plate indications and efficacy were investigated in the treatment of a life-threatening multiple rib fractures.

METHODS

A retrospective analysis of 248 surgically treated rib fracture patients was performed who admitted to our hospital from March 2007 to December 2012. Intramedullary nailing was performed in 28 cases, a claw-type bone plate was fixed in 141 cases, and a combination of both was fixed in 79 cases.

RESULTS

All internal fixation patients were clinically cured except 1 patient died 14 days after a massive pulmonary embolism. The patients with flail chest and floating chest wall causing respiratory and circulatory disorders were promptly corrected. Routine follow-up was from 1 to 2 years, displaced fractures were in 2 cases, and there were 11 cases of internal fixation and extraction.

CONCLUSION

Internal fixation is a simple and reliable method for the treatment of multiple rib fractures. Both internal fixation materials have their pros and cons but the claw bone plate is more robust. The actual selection of appropriate treatment options helps to improve the treatment efficacy.

Limits on spin-dependent WIMP-nucleon cross sections from 225 live days of XENON100 data

We present new experimental constraints on the elastic, spin-dependent WIMP-nucleon cross section using recent data from the XENON100 experiment, operated in the Laboratori Nazionali del Gran Sasso in Italy. An analysis of 224.6 live days×34 kg of exposure acquired during 2011 and 2012 revealed no excess signal due to axial-vector WIMP interactions with 129Xe and 131Xe nuclei. This leads to the most stringent upper limits on WIMP-neutron cross sections for WIMP masses above 6 GeV/c², with a minimum cross section of 3.5×10(-40) cm² at a WIMP mass of 45 GeV/c², at 90% confidence level.

Micromechanical PDGF recognition via lab-on-a-disc aptasensor arrays

A plug-and-play CD-like platform is used to perform a statistical detection of platelet derived growth factor (PDGF) proteins through aptamer-based surface functionalization of multiple microcantilever arrays. When PDGF proteins bind to aptamer coatings, the cantilevers deflect. The deflection response is monitored by optical read-out units from a commercial DVD-ROM device. We report on the use of an improved sensing platform which facilitates measurements under continuous liquid flow and with temperature control. Also, the mechanical wobbling of the DVD-ROM platform has been minimized and the scanning system has been optimized in order to detect cantilever deflections in liquid with nanometer scale resolution. The capability of the sensing platform is demonstrated by detection of clinically relevant concentrations of PDGF proteins. We present statistical measurements on 100 microcantilevers at different concentrations of PDGF, ranging from 10 nM to 400 nM. Hereby it is possible to reliably characterize the averaged mechanical response of cantilevers as a function of protein concentration.

1,25-dihydroxyvitamin D3 inhibits nuclear factor kappa B activation by stabilizing inhibitor IκBα via mRNA stability and reduced phosphorylation in passively sensitized human airway smooth muscle cells

Excessive activation of nuclear transcription factor-κB (NF-κB) is involved in human airway smooth muscle cells (HASMCs) activities in asthma. We investigated the effects of 1,25 - dihydroxyvitamin D3 [1,25 - (OH) 2D3] on the NF- κB signaling pathway in passively sensitized HASMCs and the molecular mechanisms involved. HASMCs were treated with either healthy controls' serum, asthma patients' serum or pretreated with 1,25 - (OH) 2D3 prior to treatment with asthmatics' serum. At 1 h after serum treatment: electrophoretic mobility shift assay (EMSA) was used to detect NF-κB DNA binding activity; immunocytochemical staining was used to observe the nuclear translocation of NF-κB p65; Western blots were used for NF-κB p65, IκBα, and phospho-IκBα protein levels and the nuclear translocation of NF-κB p65; real-time quantitative PCR was used for NF-κB p65 and IκBα mRNA expressions; and actinomycin D treatment was used to determine IκBα mRNA stability. Our major findings were: (1) 1,25 - (OH) 2D3 significantly reduced asthma serum passively sensitized HASMCs NF-κB DNA binding activity and inhibited the nuclear translocation of NF-κB p65; (2) 1,25 - (OH) 2D3 increased the stability of IκBα mRNA with reduced IκBα phosphorylation in asthma serum passively sensitized HASMCs and significantly increased IκBα expression in these HASMCs. Inhibiting NF-κB signalling with 1,25 - dihydroxyvitamin D3 may be a therapeutic approach for controlling HASMC-related remodelling in asthma.

A structured framework for assessing sensitivity to missing data assumptions in longitudinal clinical trials

The objective of this research was to demonstrate a framework for drawing inference from sensitivity analyses of incomplete longitudinal clinical trial data via a re-analysis of data from a confirmatory clinical trial in depression. A likelihood-based approach that assumed missing at random (MAR) was the primary analysis. Robustness to departure from MAR was assessed by comparing the primary result to those from a series of analyses that employed varying missing not at random (MNAR) assumptions (selection models, pattern mixture models and shared parameter models) and to MAR methods that used inclusive models. The key sensitivity analysis used multiple imputation assuming that after dropout the trajectory of drug-treated patients was that of placebo treated patients with a similar outcome history (placebo multiple imputation). This result was used as the worst reasonable case to define the lower limit of plausible values for the treatment contrast. The endpoint contrast from the primary analysis was - 2.79 (p = .013). In placebo multiple imputation, the result was - 2.17. Results from the other sensitivity analyses ranged from - 2.21 to - 3.87 and were symmetrically distributed around the primary result. Hence, no clear evidence of bias from missing not at random data was found. In the worst reasonable case scenario, the treatment effect was 80% of the magnitude of the primary result. Therefore, it was concluded that a treatment effect existed. The structured sensitivity framework of using a worst reasonable case result based on a controlled imputation approach with transparent and debatable assumptions supplemented a series of plausible alternative models under varying assumptions was useful in this specific situation and holds promise as a generally useful framework.

Dark matter results from 225 live days of XENON100 data

We report on a search for particle dark matter with the XENON100 experiment, operated at the Laboratori Nazionali del Gran Sasso for 13 months during 2011 and 2012. XENON100 features an ultralow electromagnetic background of (5.3 ± 0.6) × 10(-3) events/(keV(ee) × kg × day) in the energy region of interest. A blind analysis of 224.6 live days × 34 kg exposure has yielded no evidence for dark matter interactions. The two candidate events observed in the predefined nuclear recoil energy range of 6.6-30.5 keV(nr) are consistent with the background expectation of (1.0 ± 0.2) events. A profile likelihood analysis using a 6.6-43.3 keV(nr) energy range sets the most stringent limit on the spin-independent elastic weakly interacting massive particle-nucleon scattering cross section for weakly interacting massive particle masses above 8 GeV/c(2), with a minimum of 2 × 10(-45) cm(2) at 55 GeV/c(2) and 90% confidence level.

Perianal necrotizing fasciitis treated with a loose-seton technique

AIM

The study evaluated the effect of a loose-seton technique for perianal necrotizing fasciitis.

METHOD

The medical records of seven patients with perianal necrotizing fasciitis treated by the loose-seton technique between December 2005 and June 2010 were reviewed. Age, gender, status of diabetes mellitus, duration of symptoms, the length of hospital stay and number of debridements were investigated.

RESULTS

Five of the patients were men. The mean age was 53 years and the range was 43-79 years. All seven patients had a past history of acute perianal abscess. Six (85.7%) patients had diabetes mellitus. The mean time for removal of the seton was 24 (14-32) days and the mean hospitalization time was 31 (23-45) days. All patients had primary wound healing. There was no mortality. At a median follow-up 18 (6-60) months one patient required inpatient treatment with cutting-seton for complex anal fistula after 11 months. All patients had normal faecal continence and none of them required a reconstructive procedure during the follow-up.

CONCLUSION

The loose-seton technique is an effective treatment for perianal necrotizing fasciitis. The advantages include inhibiting the spread of inflammation, reducing the frequency of debridements, decreasing the area of the wound and limiting extensive scar formation.