Palladium (0) nanoparticles distributed on lanthanum (III) oxide as an effective catalyst for the methanolysis of hydrazine-borane to produce hydrogen.

Pd (0) nanoparticles (NPs) distributed on lanthanum (III) oxide were ex situ generated from the reduction of Pd2+ ions using NaBH4 as reducing agent. The Pd/La2O3 displayed good catalytic activity in H2(g) releasing from the hydrazine-borane (HB) methanolysis reaction and it was identified by advanced techniques. Pd/La2O3 was found to be an active catalyst procuring three equiv. H2(g) per mole of HB. The results from TEM images represent the formation of Pd (0) NPs with an average particle size of 1.94 ± 0.1 nm on the surface of La2O3. Moreover, Pd/La2O3 with various Pd loadings were prepared and tested as catalyst in the methanolysis reaction to find the optimum metal loading on La2O3 support. The highest H2 formation rate was achieved with 3.0 wt% Pd. Pd/La2O3 catalyst exhibited a turnover frequency (TOF) value of 24.4 mol H2 mol Pd-1 min-1 in the reaction conditions. Additionally, the effect of different catalyst concentrations and temperatures on the reaction kinetics for the methanolysis of HB catalyzed by Pd/La2O3.

Synthesis and characterization of Pd0 nanoparticles supported over hydroxyapatite nanospheres for potential application as a promising catalyst for nitrophenol reduction.

Nitrophenols, which are defined as an important toxic and carcinogenic pollutant in agricultural and industrial wastewater due to their solubility in water, form of resistance against all organisms in water resources. It is vital that these compounds, which are highly toxic as well as highly explosive, are removed from the aquatic ecosystem. In this paper, we reported the preparation and advanced characterization of Pd0 nanoparticles supported over hydroxyapatite nanospheres (Pd0@nano-HAp). The catalytic efficiency of the Pd0@nano-HAp catalyst was examined in the reduction of nitrophenols in water in the presence of NaBH4 as reducing agent and the great activity of catalyst have been specified against 2-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol and 2,4,6-trinitrophenol compounds with 70.6, 82.4, 27.6 and 41.4 min-1 TOFinitial values, respectively. Another important point is that the Pd0@nano-HAp catalyst has perfect reusability performance (at 5th reuse between 68.5 and 92.8 %) for the reduction of nitrophenols. In addition, catalytic studies were carried out at different temperatures in order to determine thermodynamic parameters such as Ea, ΔH≠ and ΔS≠.

Increased expression of ubiquitin C-terminal hydrolase L1 in astrocytomas of ascending grades.

BACKGROUND: The ubiquitin-proteasome pathway controls the monitoring and degradation of important proteins and is involved in several cellular processes, such as development, differentiation, and transcriptional regulation. Recent evidence has shown that ubiquitin carboxy-terminal hydrolase-L1 (UCH-L1), a member of the deubiquitinating enzyme family that removes ubiquitin from protein substrates, is overexpressed in many types of cancer. AIM: This study thus examined the expression of UCH-L1 in human astrocytoma tissues. MATERIAL AND METHODS: Formalin-fixed, paraffin-embedded astrocytoma samples were obtained from 40 patients, after which histopathological examination, typing, and grading were performed. The study group included 10 histologically normal brain tissues, which served as the control group, and 10 WHO grade II, 10 WHO grade III, and 10 WHO grade IV (glioblastoma) samples. Normal brain tissue samples were obtained from the histologically normal, non-tumoral portion of the pathology specimens. UCH-L1 expression was evaluated using quantitative reverse transcription-polymerase chain reaction and immunohistochemistry. RESULTS: Astrocytoma tissues exhibited higher UCH-L1 expression compared to the control group. UCH-L1 overexpression increased significantly together with the increase in astrocytoma grades (from II to IV). CONCLUSION: UCH-L1 could be a good diagnostic and therapeutic marker for determining astrocytoma development and progression.

A novel highly active and reusable carbon based platinum-ruthenium nanocatalyst for dimethylamine-borane dehydrogenation in water at room conditions.

In this paper, we present platinum/ruthenium nanoparticles supported on Vulcan carbon (PtRu@VC) as a nanocatalyst for the dehydrogenation of dimethylamine-borane (DMAB) in aqueous solution under mild conditions. PtRu@VC nanocatalyst was fabricated using the alcohol-reduction techniques which is a facile and effective method. The prepared PtRu@VC nanocatalyst exhibited a good stabilization and an effective catalytic activity for hydrogen evolution from the DMAB dehydrogenation in water at room temperature. The composition of PtRu@VC nanocatalyst was investigated using different analytical techniques inductively coupled plasma optical emission spectroscopy (ICP-OES), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), powder X-ray diffraction (P-XRD) and X-ray photoelectron spectroscopy (XPS). A monodispersedPt/Ru metals distributions on VC (as supporting material) were revealed by TEM and HR-TEM analyses. The mean particle size of PtRu@VC nanocatalyst was found to be 3.15 ± 0.76 nm. XPS analysis for PtRu@VC nanocatalyst showed that almost Pt-Ru metals were found to be the metallic state. Catalytic experimental results showed that PtRu@VC nanocatalyst has a high catalytic activity with an excellent turn-over frequency (TOFinitial) value of 14926.2 h-1 (248.77 min-1) in the dehydrogenation of DMAB in water at room temperature. Additionally, in the paper, we report some different kinetic data obtained from different experimental parameters of temperature, catalyst and substrate concentrations conducted for DMAB dehydrogenation in water catalyzed with PtRu@VC nanocatalyst.

Polypyrrole-multi walled carbon nanotube hybrid material supported Pt NPs for hydrogen evolution from the hydrolysis of MeAB at mild conditions.

Herein, we report a facile method for the preparation of polypyrrole-multi walled carbon nanotube hybrid material including Pt nanoparticles (Pt@PPy-MWCNT NPs) and the use in methylamine borane (MeAB) for hydrolysis reaction at mild conditions. The prepared catalyst of Pt@PPy-MWCNT NPs was characterized by some advanced analytical methods. The catalytic experiments showed the Pt@PPy-MWCNT NPs can catalyze MeAB in aquatic solution with high catalytical performance at mild conditions. The reaction rate of catalytic hydrolysis with Pt@PPy-MWCNT NPs was found to be -d[CH3NH2BH3]/dt = + d[H2]/3dt = kobs[Pt@PPy-MWCNT]1.19 [MeAB]0.88. The TOF value for the hydrolysis of MeAB catalyzed with Pt@PPy-MWCNT NPs was detected to be 10234.2 1/h (170.57 1/min) which is very high compared with TOF values found for other catalysts. Enthalpy, entropy and activation energy for the hydrolysis of MeAB were calculated to be 31.57 kJ mol-1, -119.97 J mol-1 K and 34.27 kJ mol-1, respectively.

Single-walled carbon nanotube supported Pt-Ru bimetallic superb nanocatalyst for the hydrogen generation from the methanolysis of methylamine-borane at mild conditions.

Several metal nanoparticle based catalysts have been synthesized for catalyzing the hydrogen production process by hydrolysis of methylamine-borane (MeAB). However, there was only one study that catalyzes the producing of hydrogen via the methanolysis of MeAB, and it was carried out by our research group. For this reason, in this work, a new catalyst system entitled by single-walled carbon nanotube (SWCNT) supported bimetallic platinum-ruthenium nanoparticles were developed and called as PtRu@SWCNT. These NPs were characterized by several techniques (XRD, XPS, Raman, and TEM), and they were performed for the methanolysis of MeAB with high catalytic activity. The prepared PtRu@SWCNT NPs were also tested in the methanolysis of MeAB at different parameters including different temperatures, catalyst and substrate concentrations, and reusability performance. Experimental results revealed that the new PtRu@SWCNT NPs had excellent catalytic activity and reusability for removing of hydrogen from the methanolysis of MeAB at ambient conditions. According to the obtained data, the turnover frequency is 136.25 mole H2/mole PtRu × min, and the activation energy (Ea) is 17.29 kJ/mole. More than 99% of conversion was observed at room temperature.

The effects of steroids in traumatic thoracolumbar junction patients on neurological outcome.

BACKGROUND: In this study, we aim to evaluate the potential effects of methylprednisolone on the neurological outcome of spinal cord injury (SCI) patients with thoracolumbar junction (T10-L1) spine fractures. METHODS: The data from 182 SCI patients who sustained a thoracolumbar junction spine fracture were operated by us between September 2008 to January 2015 were analysed retrospectively. The patients were divided into two groups: Group 1 underwent methylprednisolone treatment in conjunction with early surgical intervention, while group 2 underwent only early surgical intervention without methylprednisolone treatment. American Spinal Injury Association (ASIA) motor index scores of the patients were evaluated and compared with statistical methods at admission and at the first-year follow-up. RESULTS: The main follow-up period was 14.4±1.4 months in group 1 and 13.6±1.7 months in group 2. Initial and last follow-up ASIA scores of the patients were similar between groups (p>0.05), but the complication rate was significantly high in group 1 (p<0.05). CONCLUSION: The findings showed that steroids have no significant beneficial effects on the neurological outcome but have significant side effects and leads to increased complication rate in SCI patients.

Ex situ synthesis and characterization of a polymer-carbon nanotube-based hybrid nanocatalyst with one of the highest catalytic activities and stabilities for the hydrolytic dehydrogenation of hydrazine-borane at room temperature conditions.

In this study, a facile ex situ synthesis of a polyaniline-multiwalled carbon nanotube-based Pt nanocatalyst (Pt@PANI-MWCNT) with an average particle size of 3.18 ±â€¯0.12 nm was performed successfully. The obtained Pt@PANI-MWCNT nanocatalysts were isolated from the solution medium by centrifugation and then were characterized by spectroscopy and microscopy methods. The characterization studies showed that the prepared Pt nanoparticles were formed on PANI-MWCNT surface, and H2 evolution was obtained by the dehydrogenation of hydrazine-borane in water as a model reaction under room temperature conditions, with the help of the synthesized nanocatalyst. It was observed that the Pt@PANI-MWCNT nanocatalyst had a very high catalytic activity for the hydrolytic dehydrogenation of hydrazine-borane and generated 2.95 mol of H2 for 1 mol of hydrazine-borane. The initial turn-over frequency (TOFinitial) value of the prepared nanocatalyst for the model reaction at room temperature conditions was found to be 168.5 min-1. The calculations for the kinetics of the hydrolytic dehydrogenation reaction showed that the hydrazine-borane catalytic reaction kinetics are first order, with respect to the catalyst concentration; several activation parameters, such as entropy (ΔS#, app = -72.11 ±â€¯3 J/mol K), enthalpy (ΔH#, app = 43.5 ±â€¯2 kJ/mol) and activation energy (Ea,app = 45.5 ±â€¯2 kJ/mol), of the catalytic reaction with the Pt@PANI-MWCNT nanocatalyst were calculated using these kinetic data.

Palladium nanoparticles decorated on amine functionalized graphene nanosheets as excellent nanocatalyst for the hydrogenation of nitrophenols to aminophenol counterparts.

We reported the improved catalytic property of Pd (0) nanoparticles decorated on amine-functionalized graphene nanosheets (Pd/GNS-NH2) for the hydrogenation of nitrophenol derivatives in the presence of NaBH4 at moderate conditions. Pd/GNS-NH2 nanocatalyst was synthesized by the deposition-reduction method. Sundry techniques such as ICP-OES, P-XRD, XPS, TEM, HR-TEM and EDX have been applied to explain the structure and morphology of the Pd/GNS-NH2 nanocatalyst. The results show that the Pd (0) nanoparticles are perfectly dispersed on the surface of the GNS-NH2 support material (dmean = 1.38-2.63 nm). The catalytic activity of the Pd/GNS-NH2 nanocatalyst was tested in the hydrogenation of nitrophenol derivatives in water in the presence of NaBH4 as reductant and the excellent activity of nanocatalyst have been detected against 2-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol and 2,4,6-trinitrophenol derivatives with 116.8, 65.9, 42.8 and 11.4 min-1 initial TOF values, respectively. Another important point is that the nanocatalyst has very high reusability performance (at 5th reuse between 71.5 and 91.5%) for the hydrogenation of nitrophenols. Finally, catalytic studies have been carried out at various temperatures to calculate the Ea, ΔH≠ and ΔS≠.

Neuroprotective Effects of Tocilizumab on Experimentally-Induced Spinal Cord Ischemia-Reperfusion Injury.

OBJECTIVES: We aimed to evaluate neuroprotective effects of tocilizumab on spinal cord ischemia-reperfusion (I/R) injury. Our study design was an experimental rabbit spinal cord I/R injury model, and the setting was at the Animal Research Laboratory, Necmettin Erbakan University, Meram School of Medicine, Konya, Turkey. METHODS: Twenty-four adult New Zealand rabbits were randomly divided into 3 groups: Group 1, control group (n = 8); Group 2, I/R group, and Group 3 (n = 8) I/R injury + tocilizumab (4 mg/kg, ip) treatment group. Spinal cord I/R injury repair was performed by infrarenal aortic cross clamping. On neurologic evaluation, spinal cord tissue plasma tumor necrosis factor alpha (TNFα), total antioxidant status (TAS), total oxidant status (TOS), thiobarbituric acid reactive substances (TBARS), interleukin 6 (IL-6), interleukin 10 (IL-10) levels were analyzed. Spinal cord neuronal damage score and apoptotic cell count were also investigated. RESULTS: I/R injury significantly increases the plasma and spinal cord tissue TNFα, TOS, TBARS, and IL-6 levels and decreases the plasma and spinal cord tissue TAS and IL-10 levels. Tocilizumab treatment significantly reduces the plasma and spinal cord tissue TNFα, TOS, TBARS, IL-6 levels and increases plasma and tissue TAS and IL-10 levels. I/R injury significantly increases spinal cord neuronal damage score and apoptotic cell count. Tocilizumab treatment significantly reduces spinal cord neuronal damage score and apoptotic cell count. Neurologic examination scores at 24, 48, and 72 hours were significantly better in the treatment group when compared with the I/R group. CONCLUSIONS: This study shows significant neuroprotective effects of tocilizumab on rabbit spinal cord I/R injury.

Carbon-nanotube-based rhodium nanoparticles as highly-active catalyst for hydrolytic dehydrogenation of dimethylamineborane at room temperature.

In this study, we present a carbon nanotube-based Rh nanomaterial as a highly active catalyst for the hydrolytic dehydrogenation of dimethylamine - borane (DMAB) at room temperature. The prepared multi-walled carbon nanotube based Rh nanoparticles, called Rh NPs@ MWCNT, was readily prepared, stabilized and effectively used for the hydrolytic dehydrogenation of DMAB under ambient conditions. Monodisperse Rh NPs@ MWCNT nanocatalyst was characterized by using advanced analytical methods such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM) etc. These analytical methods revealed that Rh nanoparticles on the surface of MWCNT were well dispersed and the average particle size was found to be 1.44 ±â€¯0.17 nm. The catalytic experiments revealed that the new Rh NPs@MWCNT nanocatalyst has a high catalytic effect to obtain hydrogen in 3.0 equation from DMAB, and the record catalytic TOF value for the catalytic reaction catalyzed by Rh NPs@MWCNT nanocatalyst was found to be 3010.47 h-1 at room temperature. The current study presents the detailed kinetic studies of the hydrolytic dehydrogenation of DMAB catalyzed by Rh NPs@MWCNT, the results of catalytic experiments were performed at different temperatures, substrate and catalyst concentrations, the Rh NPs@MWCNT nanocatalyst was effectively used in the completion of the hydrolytic dehydrogenation of DMAB, and activation energy, enthalpy and entropy parameters. The experimental results showed that monodisperse Rh NPs@MWCNT nanocatalyst have record catalytic activity with TOF value of 3010.47 h-1, and Rh(0) nanoparticles were well dispersed on the multi-walled carbon nanotubes.

New Clues in the Malignant Progression of Glioblastoma: Can the Thioredoxin System Play a Role?

AIM: To evaluate and compare the expression of thioredoxin reductase 1 (TrxR1) in primary and secondary glioblastoma samples. MATERIAL AND METHODS: Surgically resected human glioblastoma samples from 40 patients who underwent surgery at our institution were extracted from their histopathological specimens and divided into three groups. Ten histopathologically regular cerebral tissue samples, acquired from the non-neoplastic portion of the specimens, were assigned as the control group. Twenty specimens that included tumoral tissue from each type of glioblastoma (WHO grade IV, primary and secondary) were assigned as the primary and secondary glioblastoma groups. TrxR1 expression was analyzed by using both quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry. Isocitrate dehydrogenase 1 (IDH1) mutation was analyzed by immunohistochemistry. Ki-67 proliferative index and apoptosis were also analyzed by immunohistochemistry. The differences between the groups were statistically compared and the correlation between these parameters was analyzed. RESULTS: The expressions of TrxR1 and Ki-67 values were significantly higher in primary glioblastoma. IDH1 mutation was significantly higher in secondary glioblastoma. TrxR1 expression was found to be highly correlated with the Ki-67 index. The apoptotic index was similar between primary and secondary glioblastoma. CONCLUSION: This study showed a high TrxR1 expression in primary glioblastoma which could indicate a role of the Trx system in promoting the malignant progression by some complex processes.

Intratumoral hemorrhage-related differences in the expression of vascular endothelial growth factor, basic fibroblast growth factor and thioredoxin reductase 1 in human glioblastoma.

The present study was designed to evaluate the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and thioredoxin reductase 1 (TrxR1) in glioblastoma multiforme (GBM) with and without intratumoral hemorrhage. Surgically resected human GBM samples from 20 patients who underwent surgery at our institute were extracted from the histopathological specimens and divided into two groups. A total of 10 samples from each type of GBM (World Health Organization grade IV, intratumoral hemorrhage-positive or -negative) were included in each group. VEGF, bFGF and TrxR1 expression was analyzed using immunohistochemistry and the results were compared between groups. VEGF and bFGF immunoreactivity was significantly higher in GBMs containing intratumoral hemorrhage. Furthermore, VEGF, bFGF and TrxR1 immunointensity was significantly higher in GBMs containing intratumoral hemorrhage. Thus, the present study demonstrated a higher VEGF, bFGF and TrxR1 expression in GBMs contain intratumoral hemorrhage, indicatiogn a role of VEGF, bFGF and TrxR1 expression in the promotion of tumoral angiogenesis and tumoral growth by complex mechanisms that require further elucidation.

A case of symptomatic synchronous cervical and cerebellar metastasis after resection of thoracal metastasis from temporal glioblastoma multiforme without any local recurrence.

Glioblastoma multiforme (GBM) is the most common and the most malignant primary intracranial tumor in adults and it is usually occurs between the age of 40 and 60 years. It is local invasive and recurrent tumor and hence that has a poor prognosis. However, recent advances in tumor surgery, irradiation and chemotherapeutic agent permit long survival and metastasis which is symptomatic. Previously studies reported spinal metastasis, but we report a first case of synchronous symptomatic cerebellar and cervical spinal metastasis after resection of symptomatic thoracic spinal metastasis from temporal GBM without any recurrence of excision areas.

Telmisartan ameliorates oxidative stress and subarachnoid haemorrhage-induced cerebral vasospasm.

OBJECTIVES: Growing evidence suggests that oxidative stress is one of the factors contributing to subarachnoid haemorrhage (SAH)-induced cerebral vasospasm. SAH-induced cerebral vasospam alters thioredoxin (Trx) cycle enzymes and thioredoxin-interacting protein (TXNIP) as an important endogenous antioxidant system. In this study, we have explored the effects of telmisartan on the vascular morphological changes, endothelial apoptosis, tissue oxidative stress status and the level of Trx cycle enzymes/ TXNIP in a rabbit SAH model. METHODS: Forty male New Zealand rabbits were randomly divided into five groups of eight rabbits each: control group, sham group, SAH group, SAH + vehicle group and SAH + telmisartan group. SAH was created by a single cisterna magna blood injection. SAH + telmisartan group received telmisartan treatment (5 mg/kg intraperitoneal, once daily) for 72 h. The brainstem tissue Trx1, Trx2, Trx reductase (TrxR), TrxR1and TXNIP levels were investigated. Total oxidant status (TOS), total antioxidant status (TAS), malondialdehyde (MDA) levels and tumour necrosis factor alpha (TNF alpha) levels were investigated. Basilar artery segments were investigated for cross-sectional area, wall thickness measurements and endothelial apoptosis. RESULTS: Telmisartan treatment restored the lowered level of Trx1, TrxR, TAS and the expression of TrxR1 seen in SAH. Telmisartan treatment also decreased TXNIP expression, TOS, MDA and TNF alpha levels. Morphological changes of cerebral vasospasm were attenuated after treatment. Endothelial apoptosis significantly reduced. DISCUSSION: Treatment with telmisartan ameliorates oxidative stress and SAH-induced cerebral vasospasm in rabbits. These effects of telmisartan may be associated with downregulation of TXNIP and upregulation of Trx/TrxR.

Effect of Carvedilol on Secondary Damage in Experimental Spinal Cord Injury in Rats.

AIM: Previous studies have shown that carvedilol has a neuroprotective effect in animal models of brain ischemia and brain oxidative damage in vitro. This study was perfomed to investigate the effect of carvedilol on the secondary damage in experimental spinal cord injury (SCI). MATERIAL AND METHODS: Twenty-four Wistar albino rats were divided into three groups. Group 1 underwent laminectomy alone. Group 2 underwent laminectomy followed by SCI and received carvedilol. Group 3 underwent laminectomy followed by SCI and received no medication. The neurological functions were assessed by Tarlov's motor scale at the first and 24th hours. Oxidative stress status was assessed by MDA, SOD, MPO, GSH activities. A TUNEL-based apoptosis kit was used for evaluating apoptosis in the spinal cord samples and hematoxylinand eosin-stained specimens were used for light microscopic examination. RESULTS: Carvedilol reduced apoptosis and regulated oxidant and antioxidant status by increasing SOD and GSH levels and reducing MPO and MDA levels in the spinal tissue homogenate. Neurological examination of rats revealed statistically significant improvement 24 hours after the trauma. CONCLUSION: Carvedilol has a statistically significant therapeutic effect, especially on functional recovery, and we found that carvedilol reduced secondary damage by inhibiting apoptosis and regulating the oxidant and antioxidant status.

Transition metal(II) complexes of a novel symmetrical benzothiazole-based ligand: synthesis, spectral/structural characterization and fluorescence properties.

2,6-bis (benzothiazol-2-yl)-4-(tert-butyl) phenol ligand (HL) derived from o-aminothiophenol and 4-tert-butyl-2,6-diformylphenol was synthesized and characterized by using elemental analysis, FTIR, X-ray crystallographic analysis, (1)H and (13)C-NMR and UV-vis spectra. Its complexes with Cu (II), Ni (II) and Co (II) were prepared and isolated as solid products and characterized by elemental analysis, spectral techniques as well as magnetic susceptibility. The FTIR spectra showed that the benzothiazole-based ligand under investigation behaves as a bidentate ligand. The UV-vis spectra and magnetic moment data suggested an octahedral geometry around Ni (II) and Co (II) complexes, and tetragonal geometry for Cu (II) complex. Moreover, the evaluation of absorption and emission properties of the ligand and its complexes were carried out in different solvents. The ligand and its complexes showed absorption maxima in the range of 275 - 432 nm, and emission maxima from 367 to 581 nm in toluene, tetrahydrofuran and ethyl acetate.