The separation of gas molecules and water vapor has become increasingly important for electronic, energy, and environmental systems. Here we demonstrate a new mechanism of enhanced condensation, agglomeration, and rejection of water vapor by superhydrophobic aligned multiwalled carbon nanotubes with the intertube distance of 73 nm, channel aspect ratio of ~5.5 × 10(4), and tortuosity of 1.157. The array with the characteristic channel dimension some 300 times greater than the target molecule size effectively suppressed water molecular transport at room temperature with the selectivity as high as ~2 × 10(5) (H(2)/H(2)O). The flow through the interstitial space of nanotubes allowed high permeability of other gas molecules (2.1 × 10(-9) to 3.8 × 10(-8) mol · m/m(2) · s · Pa), while retaining high selectivity, which is orders of magnitude greater than the permeate flux of polymeric membranes used for the water-gas mixture separation. This new separation mechanism with high selectivity and permeate flux, enabled by the unique geometry of aligned nanotubes, can provide a low-energy and cost-effective method to control humidity.

The cytotoxicity of alumina nanoparticles (NPs) was investigated for a wide range of concentration (25–200 μg/mL) and incubation time (0–72 h) using floating cells (THP-1) and adherent cells (J774A.1, A549, and 293). Alumina NPs were gradually agglomerated over time although a significant portion of sedimentation occurred at the early stage within 6 h. A decrease of the viability was found in floating (THP-1) and adherent (J774A.1 and A549) cells in a dose-dependent manner. However, the time-dependent decrease in cell viability was observed only in adherent cells (J774A.1 and A549), which is predominantly related with the sedimentation of alumina NPs in cell culture medium. The uptake of alumina NPs in macrophages and an increased cell-to-cell adhesion in adherent cells were observed. There was no significant change in the viability of 293 cells. This in vitro test suggests that the agglomeration and sedimentation of alumina NPs affected cellular viability depending on cell types such as monocytes (THP-1), macrophages (J774A.1), lung carcinoma cells (A549), and embryonic kidney cells (293).

The frictional performances of activated carbon, carbon blacks, mesoporous carbons, and carbon nanotubes were compared as lubricant additives to mineral oils using a ball-on-disk tester at ambient temperature. Well-dispersed, smaller particles with a uniform size were more effective in maintaining the oil gaps and the protecting surfaces. However, the effects of different atomic structures of carbon particles on tribological performances were minimal as long as the particle sizes are of similar order.

We investigated the electrical transport response of single-walled carbon nanotube (SWNT) arrays exposed to ultraviolet (UV) and ozone (O3). Pure UV irradiation induced an increase in resistance due to molecular photodesorption on the nanotubes. The effect of the O3 treatment on the resistance of SWNT arrays depended on the degree of O3 due to different dominant mechanisms, including the transduction of molecular adsorption and O3 doping on nanotubes as well as the creation of defects. The results suggest that the detailed control of UV/O3 exposure could be useful in manipulating electrical devices using SWNT arrays.

We have investigated the effect of ultraviolet irradiation exposure time on single walled carbon nanotubes (SWNTs) wrapped with single-strand DNA (ssDNA) using absorption spectroscopy and Raman spectroscopy. The absorbance value of ssDNA-wrapped SWNTs in aqueous media was found to be decreased, where as SWNTs wrapped with ssDNA with polyd(T) were aggregated under UV irradiation.

Single-walled carbon nanotubes (SWCNTs) exhibit sharp absorption peak distributions in the UV–vis–nIR range when they are individually dispersed in aqueous solution medium. In this paper, we developed SWCNT-based molecular probes by conjugating single-stranded DNA (ssDNA) with SWCNT. The DNA hybridization event was investigated using the absorption spectra of the ssDNA–SWCNT probes. The results showed that DNA hybridization on the sidewall of SWCNT resulted in systematic red shifts of the absorption spectra of semiconducting nanotubes. However, metallic species did not show any shift in the absorption spectra. The work demonstrated that ssDNA–SWCNTs probes might be used to detect specific kinds of DNA oligonucleotides as optical nano-biosensors.

A quantitative method to evaluate the degree of dispersion of single-walled carbon nanotubes (SWCNTs), produced by the high-pressure carbon monoxide process, was developed using Raman spectroscopy and atomic force microscopy (AFM). Nanotubes were dispersed in sodium dodecyl sulfate aqueous solution at seven different dispersion states by controlling ultra-sonication and centrifugation parameters. It is known that the intensity of a Raman peak at 267cm−1, at the excitation wavelength of 785nm, is qualitatively proportional to the degree of aggregation. Here, we provide a quantitative calibration technique which involves single-layer spin-deposition of SWCNTs on mica substrates and z-scan analysis of AFM. The trend of the height measurements of AFM precisely matched that of the Raman peak at 267cm−1. Therefore, this approach can be used to quantitatively characterize the dispersion state of SWCNTs.

We have investigated quantitative measurement techniques of the degree of dispersion of single-walled carbon nanotubes (SWNTs). SWNTs were suspended in aqueous media using a sodium dodecyl sulfate (SDS) surfactant. SWNTs with different dispersion states were prepared by controlling the intensity and time of sonication and centrifugation. The laser spectroscopic techniques were employed to characterize the dispersion state; i.e., raman fluorescence and absorption spectroscopic techniques. Raman spectroscopy has been used to probe the dispersion and aggregation state of SWNTs in solution. Individually suspended SWNTs show increased fluorescence peaks and decreased roping peaks at a raman shift 267 cm(-1) compared with the samples containing bundles of SWNTs. The ultraviolet-visible-near infrared (UV-vis-NIR) absorption spectrum of decanted supernatant samples show sharp van Hove singularity peaks

We have investigated the degree of dispersion of single-walled carbon nanotubes (SWNTs) in solution using laser spectroscopic techniques. SWNTs were suspended in aqueous media using a sodium dodecyl sulfate (SDS) surfactant. SWNTs with different dispersion states were prepared by controlling the intensity and duration of sonication and centrifugation. The absorption and fluorescence spectroscopic techniques were employed to characterize the different dispersion state of the prepared samples. Nanotube suspensions with better dispersion showed higher fluorescence and sharper absorption peaks. The fluorescence data were characterized as a function of the nanotube chirality, and absorption peak shifts were analyzed depending on the first and second van Hove singularities (vHs) of semiconducting nanotubes.

Brain-derived neurotrophic factor (BDNF), the most abundant neurotrophin in the brain, has a known association with the pathophysiology of anxiety and depression. However, the role of BDNF in suicide has not been well investigated to date. This study examined plasma BDNF levels in 32 major depressive disorder (MDD) patients who had recently attempted suicide, 32 non-suicidal MDD patients, and 30 normal controls. The lethality of the suicide attempt was measured using the Risk-Rescue Rating (RRR) and Lethality Suicide Attempt Rating Scale (LSARS). The severity of depression was measured with the Hamilton Depression Rating Scale (HDRS). Plasma BDNF levels were measured by enzyme linked immunosorbent assay. BDNF levels were significantly lower in suicidal MDD patients (430.5 +/- 397.0 pg/ml) than non-suicidal MDD patients (875.80 +/- 663.02 pg/ml) or normal controls (889.4 +/- 611.3 pg/ml) (F = 6.682, p = 0.002), The most suitable cut-off point of BDNF level between suicidal depression and non-suicidal depression groups was 444.58 pg/ml, At this cut-off point, the sensitivity = 68.7%, specificity = 78.1%, positive predictive value = 75.9%, and negative predictive value = 71.4%. However, there was no significant difference in BDNF levels between the depressive control and normal control groups (p = 0.996). LSARS and RRR did not reveal any significant correlations with BDNF levels in suicidal patients. In addition, BDNF levels were not different between fatal and non-fatal suicide attempts. These results suggest that reduction of plasma BDNF level is related to suicidal behavior in major depression and that BDNF level may be a biological marker of suicidal depression. (c) 2006 Elsevier Inc. All rights reserved.

Many hypotheses have put forward to better understand the pathogenesis of schizophrenia (SZ), such as synaptic pruning, stress-diathesis, neurodevelopment, neurodegeneration and neurotransmitter hypothesis; nonetheless, this pathogenesis still remains a mystery. The current study was designed with the hypothesis that impairment of a balance between pro-BDNF/mature BDNF and their receptors p75NTRK/TrkB may cause synaptic pruning in the pathogenesis of psychotic disorders.Sixty-five drug-naïve patients with first-episode psychosis (FEP) who applied to outpatient clinics and were diagnosed according to DSM-5 as well as 65 healthy controls (HC) were included in the study. Symptoms at the time of evaluation were assessed with the PANSS scale by an experienced psychiatrist. Blood samples were collected from all participants to determine BDNF, pro-BDNF, TrkB and p75NTR, PAI1, tPA, ACTH and cortisol levels.Mature BDNF, TrkB and PAI-1, tPA levels were significantly lower while the levels of ACTH and cortisol were significantly higher in FEP patients compared to HC. No significant difference was found in pro-BDNF and p75NTR levels between the two independent groups. The pro-BDNF/mature BDNF and the p75NTR/TrkB ratios were significantly higher in FEP patients compared to HC. Moreover, the pro-BDNF/mature BDNF and the p75NTR/TrkB ratios were found to be significantly associated with the pathogenesis of SZ in a hierarchical regression model.Imbalance between neurotrophic and apoptotic proteins such as pro-BDNF/mature BDNF and p75NTR/TrkB may be take part pathogenesis of synaptic pruning in psychotic disorders.

Background:Borna disease virus (BDV) predominantly infects horses and sheep, causing a broad range of behavioural disorders. It is controversial whether BDV infects humans and causes psychiatric disorders.Objectives:We searched for BDV-derived nucleic acids in blood of race horses and jockeys riding the horses.Methods:We assayed for the BDV genome in RNA extracted from peripheral blood mononuclear cells (PBMC) of 39 race horses and 48 jockeys. Two polymerase chain reaction protocols [one-tube reverse transcription–polymerase chain reaction (RT-PCR) and two-step RT-PCR] were used to assay BDV p24 and p40 transcripts.Results:The p24 and p40 viral nucleic acid sequences were not detected in the PBMC RNAs from any of the race horses or jockeys.Conclusions:These data do not support an epidemiological association between BDV infection, race horses and humans.

Background: Nitric oxide (NO) is known to influence cerebral monoaminergic activity, including the activity of serotonin. We evaluated plasma NO metabolite (NOx) levels in depressive patients with and without a recent history of suicide attempt.Method: Plasma NOx levels were measured in 39 depressive patients who had recently attempted suicide, 44 non-suicidal depressed patients, and 70 normal controls. The severity of depression was measured with the Hamilton's Depression Rating Scale. The lethality of the suicide attempt was scored using Weisman and Worden's risk-rescue rating scale and Lethality Suicide Attempt Rating Scale.Results: Plasma NOx levels were significantly higher in suicidal depressive patients than non-suicidal depressive patients or normal control subjects (Z = -2.472, p = 0.013). However, higher plasma NOx levels in suicidal depressive patients were significantly related to a lower lethality of suicide attempts and lower severity of depression.Conclusions: Our study suggests that increased plasma NO, level is associated with suicide attempts in depressive patients. Moreover, higher plasma NO, level is related with suicide attempts in mild depressed patients. However, further studies are required to understand the role of NO system in depression and suicidal behavior. (c) 2006 Elsevier Inc. All rights reserved.

Objective: To evaluate any correlation between plasma levels of nitric oxide metabolites (NOx) and suicide attempt. Method: Plasma NOx levels were measured in 53 patients who had recently attempted suicide, 58 nonsuicidal psychiatric patients, and 75 normal controls. The severity of suicidal behaviors was evaluated using Weisman and Worden’s Risk-Rescue Rating Scale. Results: Plasma NOx levels were significantly higher in suicidal patients than nonsuicidal psychiatric patients or normal control subjects (F = 11.029, d.f. = 2, 183, p < 0.001). Among the patients with a diagnosis of major depression, suicidal depressive patients had significantly higher plasma NOx levels than nonsuicidal depressive patients (t = –3.090, d.f. = 84, p = 0.003). Conclusion: Our study suggests that increased NO production in plasma is associated with suicide attempt, especially in depressive patients.

The tribological performance of ordered mesoporous carbons (CMK-3) as lubricant additives is investigated at ambient temperature. The effects of CMK-3 on the frictional forces, wear amounts and cycles to scuffing are measured using a ball-on-disk tester. It was found that there was little difference in the frictional forces and wear amounts of the oils with and without CMK-3. However, the scuffing time of the oil with CMK-3 was much longer than that of the pure mineral oil in sliding tests. CMK-3 were very effective on maintaining the oil gap and protecting the surfaces in boundary lubricated sliding.