Photocatalytic treatment of municipal wastewater using modified neodymium doped TiO2 hybrid nanoparticles

Photocatalytic degradation of municipal wastewater was investigated using reagent grade TiO2 and modified neodymium doped TiO2 hybrid nanoparticles. For the first time, surface modification of Nd3+ doped TiO2 hybrid nanoparticles were carried out with n-butylamine as surface modifier under mild hydrothermal conditions. The modified nanoparticles obtained were characterized by Powder XRD, FTIR, DLS, TEM, BET surface area, zeta potential and UV-Vis Spectroscopy. The characterization results indicated better morphology, particle size distribution and low agglomeration of the nanoparticles synthesized. It was found that photodegradation of wastewater using surface modified neodymium doped TiO2 nanoparticles was more compared to pure TiO2, which can be attributed to the doping and modification with n-butylamine.

The effectiveness of infrainguinal percutaneous transluminal angioplasty in the treatment of critical limb ischaemia

Critical chronic lower limb ischaemia (CLI) is the most severe form of peripheral arterial disease. Even though the treatment of CLI has evolved during the last decade, CLI is still associated with considerable morbidity, mortality and a decreased quality of life, in addition to a large financial impact on society. ---- Bypass surgery has traditionally been considered the approach of choice to treat CLI patients in order to avoid amputation. However, there are increasing data on the efficacy of endovascular revascularization procedures, such as percutaneous transluminal angioplasty (PTA), to achieve good leg salvage rates as well. Data gathered on all the 2,054 CLI patients revascularized at the Helsinki University Central Hospital between 2000 and 2007 were retrospectively analyzed. This patient cohort was used to compare the results of infrainguinal PTA and bypass surgery as well as to investigate predictors of failure after PTA. This study showed that infrainguinal PTA and bypass surgery yielded rather similar results in terms of survival, amputation-free survival and freedom from any re-intervention. When the femoropoliteal segment was treated, leg salvage was significantly better in the bypass surgery group, whereas no significant difference was observed between the two treatment methods when the revascularization extended to the infrapopliteal segment. PTA resulted in a significantly lower freedom from surgical re-interventions when compared to surgical revascularization. In this study the most important predictors of poor outcome after PTA for CLI were cardiac morbidity, nonambulatory status upon hospital arrival, and gangrene as a manifestation of CLI. Thus, when feasible, PTA seems to be a valid alternative for bypass surgery in the treatment of CLI provided that active redo-surgery is utilized. The optimal revascularization strategy should always be sought for each CLI patient individually considering the clinical state of the leg, the occlusive lesions to be treated, co-morbidities, life-expectancy, and the availability of a suitable vein for bypass.

Catalytic hydrogen combustion for treatment of combustible gases from fuel cell processors

Catalytic combustion of H-2 was carried out over combustion synthesized noble metal (Pd or Pt) ion-substituted CeO2 based catalysts using a feed stream that simulated exhaust gases from a fuel cell processor The catalysts showed a high activity for H-2-combustion and complete conversion was achieved below 200 C over all the catalysts when O-2 was used in a stoichiometric amount With higher amounts of O-2 the reaction rates Increased and complete conversions were possible below 100 C The reaction was also carried out over Pd-impregnated CeO2 The conversions of H-2 with stoichiometric amount of O-2 were found to be higher over Pd-substituted compound The mechanism of the reaction over noble metal-substituted compounds was proposed on the basis of X-ray photoelectron spectroscopy studies The redox couples between Ce and metal ions were established and a dual site redox mechanism was pi posed for the reaction (C) 2010 Elsevier B V All rights reserved

Combination antiretroviral therapy -associated lipodystrophy : insights into pathogenesis and treatment

Introduction: Combination antiretroviral therapy (cART) has decreased morbidity and mortality of individuals infected with human immunodeficiency virus type 1 (HIV-1). Its use, however, is associated with adverse effects which increase the patients risk of conditions such as diabetes and coronary heart disease. Perhaps the most stigmatizing side effect is lipodystrophy, i.e., the loss of subcutaneous adipose tissue (SAT) in the face, limbs and trunk while fat accumulates intra-abdominally and dorsocervically. The pathogenesis of cART-associated lipodystrophy is obscure. Nucleoside reverse transcriptase inhibitors (NRTI) have been implicated to cause lipoatrophy via mitochondrial toxicity. There is no known effective treatment for cART-associated lipodystrophy during unchanged antiretroviral regimen in humans, but in vitro data have shown uridine to abrogate NRTI-induced toxicity in adipocytes. Aims: To investigate whether i) cART or lipodystrophy associated with its use affect arterial stiffness; ii) lipoatrophic SAT is inflamed compared to non-lipoatrophic SAT; iii) abdominal SAT from patients with compared to those without cART-associated lipoatrophy differs with respect to mitochondrial DNA (mtDNA) content, adipose tissue inflammation and gene expression, and if NRTIs stavudine and zidovudine are associated with different degree of changes; iv) lipoatrophic abdominal SAT differs from preserved dorsocervical SAT with respect to mtDNA content, adipose tissue inflammation and gene expression in patients with cART-associated lipodystrophy and v) whether uridine can revert lipoatrophy and the associated metabolic disturbances in patients on stavudine or zidovudine based cART. Subjects and methods: 64 cART-treated patients with (n=45) and without lipodystrophy/-atrophy (n=19) were compared cross-sectionally. A marker of arterial stiffness, heart rate corrected augmentation index (AgIHR), was measured by pulse wave analysis. Body composition was measured by magnetic resonance imaging and dual-energy X-ray absorptiometry, and liver fat content by proton magnetic resonance spectroscopy. Gene expression and mtDNA content in SAT were assessed by real-time polymerase chain reaction and microarray. Adipose tissue composition and inflammation were assessed by histology and immunohistochemistry. Dorsocervical and abdominal SAT were studied. The efficacy and safety of uridine for the treatment of cART-associated lipoatrophy were evaluated in a randomized, double-blind, placebo-controlled 3-month trial in 20 lipoatrophic cART-treated patients. Results: Duration of antiretroviral treatment and cumulative exposure to NRTIs and protease inhibitors, but not the presence of cART-associated lipodystrophy, predicted AgIHR independent of age and blood pressure. Gene expression of inflammatory markers was increased in SAT of lipodystrophic as compared to non-lipodystrophic patients. Expression of genes involved in adipogenesis, triglyceride synthesis and glucose disposal was lower and of those involved in mitochondrial biogenesis, apoptosis and oxidative stress higher in SAT of patients with than without cART-associated lipoatrophy. Most changes were more pronounced in stavudine-treated than in zidovudine-treated individuals. Lipoatrophic SAT had lower mtDNA than SAT of non-lipoatrophic patients. Expression of inflammatory genes was lower in dorsocervical than in abdominal SAT. Neither depot had characteristics of brown adipose tissue. Despite being spared from lipoatrophy, dorsocervical SAT of lipodystrophic patients had lower mtDNA than the phenotypically similar corresponding depot of non-lipodystrophic patients. The greatest difference in gene expression between dorsocervical and abdominal SAT, irrespective of lipodystrophy status, was in expression of homeobox genes that regulate transcription and regionalization of organs during embryonal development. Uridine increased limb fat and its proportion of total fat, but had no effect on liver fat content and markers of insulin resistance. Conclusions: Long-term cART is associated with increased arterial stiffness and, thus, with higher cardiovascular risk. Lipoatrophic abdominal SAT is characterized by inflammation, apoptosis and mtDNA depletion. As mtDNA is depleted even in non-lipoatrophic dorsocervical SAT, lipoatrophy is unlikely to be caused directly by mtDNA depletion. Preserved dorsocervical SAT of patients with cART-associated lipodystrophy is less inflamed than their lipoatrophic abdominal SAT, and does not resemble brown adipose tissue. The greatest difference in gene expression between dorsocervical and abdominal SAT is in expression of transcriptional regulators, homeobox genes, which might explain the differential susceptibility of these adipose tissue depots to cART-induced toxicity. Uridine is able to increase peripheral SAT in lipoatrophic patients during unchanged cART.

Optimal Use of Treatment Modalities and Treatment Results of Osteosarcoma and Soft Tissue Sarcomas

Soft tissue sarcomas are malignant tumours of mesenchymal origin. Because of infiltrative growth pattern, simple enucleation of the tumour causes a high rate of local recurrence. Instead, these tumours should be resected with a rim of normal tissue around the tumour. Data on the adequate margin width are scarce. At Helsinki University Central Hospital (HUCH) a multidisciplinary treatment group started in 1987. Surgical resection with a wide margin (2.5 cm) is the primary aim. In case of narrower margin radiation therapy is necessary. The role of adjuvant chemotherapy remains unclear. Our aims were to study local control by the surgical margin and to develop a new prognostic tool to aid decision-making on which patients should receive adjuvant chemotherapy. Patients with soft tissue sarcoma of the extremity or the trunk wall referred to HUCH during 1987-2002 form material in Studies I and II. External validation material comes from the Lund university sarcoma registry. The smallest surgical margin of at least 2.5 centimetres yielded local control of 89 per cent at five years. Amputation rate was 9 per cent. The proposed prognostic model with necrosis, vascular invasion, size on a continuous scale, depth, location and grade worked well both in Helsinki material and in the validation material, and it also showed good calibration. Based on the present study, we recommend the smallest surgical margin of 2-3 centimetres in soft tissue sarcoma irrespective of grade. Improvement in local control was present but modest in margins wider than 1 centimetre. In cases where gaining a wider margin would lead to a considerable loss of function, smaller margin is to be considered combined to radiation therapy. Patients treated with inadequate margins should be offered radiation therapy irrespective of tumour grade. Our new prognostic model to estimate 10-year survival probability in patients with soft tissue sarcoma of the extremities or trunk wall showed good dicscrimination and calibration. For time being the prognostic model is available for scientific use and further validations. In the future, the model may aid in clinical decision-making. For operable osteosarcoma, neoadjuvant multidrug chemotherapy followed by delayed surgery and multidrug adjuvant chemotherapy is the treatment of choice. Overall survival rates at five years are approximately 75 per cent in modern trials with classical osteosarcoma. All patients diagnosed and reported to the Finnish Cancer Registry with osteosarcoma in Finland during 1971-2005 form the material in Studies III and IV. Limb-salvage rate increased from 23 per cent to 78 per cent during 1971-2005. The 10-year sarcoma-specific survival for the whole study population improved from 32 per cent to 62 per cent. It was 75 per cent for patients with a local high-grade osteosarcoma of the extremity diagnosed during 1991-2005. This study outlines the improved prognosis of osteosarcoma patients in Finland with modern chemotherapy. The 10-year survival rates are good also in an international scale. Nonetheless, their limb-salvage rate remains inferior to those seen for highly selected patient series. Overall, the centralisation of osteosarcoma treatment would most likely improve both survival and limb-salvage rates even further.

13 C nuclear magnetic resonance studies of the binding of alkali and alkaline earth metal salts to amides

13 C resonances of carbonyl and methyl groups in amides are shifted down-field on interaction with alkali and alkaline earth metal salts. The magnitude of the shift depends on the ionic potential of the cation. Ions like Li+ bind to the amide carbonyl group both in neat amide solutions as well as in concentrated salt solutions in water.

Growth Kinetics of ZnO Nanocrystals in the Presence of a Base: Effect of the Size of the Alkali Cation

Following an earlier study (J. Am. Chem Soc. 2007, 129, 4470) describing a very unusual growth kinetics of ZnO nanoparticles, we critically evaluate here the proposed mechanism involving a crucial role of the alkali base ion in controlling the growth of ZnO nanoparticles using other alkali bases, namely, LiOH and KOH. While confirming the earlier conclusion of the growth of ZnO nanoparticles being hindered by an effective passivating layer of cations present in the reaction mixture and thereby generalizing this phenomenon, present experimental data reveal an intriguing nonmonotonic dependence of the passivation efficacy on the ionic size of the alkali base ion. This unexpected behavior is rationalized on the basis of two opposing factors: (a) solvated cationic radii and (b) dissociation constant of the base.

An Investigation Of Alkali Aluminosilicate Glasses By Si-29 And Al-27 Magic-Angle-Spinning Nmr-Spectroscopy

Alkali aluminosilicate glasses prepared by the gel and the melt routes have been investigated by Si-29 and Al-27 MAS NMR spectroscopy. It is found that Al has a tetrahedral coordination in the gel glasses modified with equivalent proportions of alkalis unlike in a pure aluminosilicate glass where Al has both four and six coordinations. Silicon is present as Q4 units in all the 5M2O 5Al2O3 9OSiO2 ( M = Li, Na and K) gel glasses studied whereas it is present in Q2 or Q3 species in the lithium aluminosilicate glasses of compositions 40Li2O x Al2O3 (1-x)SiO2 (1 less-than-or-equal-to x less-than-or-equal-to 15) and xLi2O 10Al2O3 (1-x)SiO2 (20 less-than-or-equal-to x less-than-or-equal-to 40). The combination of Q2 and Q3 is also found in certain sodium aluminosilicate glasses, but they change to Q2 and Q1 as the concentration of SiO2 decreases.

Myoblast Sheet Transplantation for Treatment of Heart Failure after Myocardial Infarction

Heart failure is a common, severe, and progressive condition associated with high mortality and morbidity. Because of population-aging in the coming decades, heart failure is estimated to reach epidemic proportions. Current medical and surgical treatments have reduced mortality, but the prognosis for patients has remained poor. Transplantation of skeletal myoblasts has raised hope of regenerating the failing heart and compensating for lost cardiac contractile tissue. In the present work, we studied epicardial transplantation of tissue-engineered myoblast sheets for treatment of heart failure. We employed a rat model of myocardial infarction-induced acute and chronic heart failure by left anterior descending coronary artery ligation. We then transplanted myoblast sheets genetically modified to resist cell death after transplantation by expressing antiapoptotic gene bcl2. In addition, we evaluated the regenerative capacity of myoblast sheets expressing the cardioprotective cytokine hepatocyte growth factor in a rat chronic heart failure model. Furthermore, we utilized in vitro cardiomyocyte and endothelial cell culture models as well as microarray gene expression analysis to elucidate molecular mechanisms mediating the therapeutic effects of myoblast sheet transplantation. Our results demonstrate that Bcl2-expression prolonged myoblast sheet survival in rat hearts after transplantation and induced secretion of cardioprotective, proangiogenic cytokines. After acute myocardial infarction, these sheets attenuated left ventricular dysfunction and myocardial damage, and they induced therapeutic angiogenesis. In the chronic heart failure model, inhibition of graft apoptosis by Bcl-2 improved cardiac function, supported survival of cardiomyocytes in the infarcted area, and induced angiogenesis in a vascular endothelial growth factor receptor 1- and 2-dependent mechanism. Hepatocyte growth factor-secreting myoblast sheets further enhanced the angiogenic efficacy of myoblast sheet therapy. Moreover, myoblast-secreted paracrine factors protected cardiomyocytes against oxidative stress in an epidermal growth factor receptor- and c-Met dependent manner. This protection was associated with induction of antioxidative genes and activation of the unfolded protein response. Our results provide evidence that inhibiting myoblast sheet apoptosis can enhance the sheets efficacy for treating heart failure after acute and chronic myocardial infarction. Furthermore, we show that myoblast sheets can serve as vehicles for delivery of growth factors, and induce therapeutic angiogenesis in the chronically ischemic heart. Finally, myoblasts induce, in a paracine manner, a cardiomyocyte-protective response against oxidative stress. Our study elucidates novel mechanisms of myoblast transplantation therapy, and suggests effective means to improve this therapy for the benefit of the heart failure patient.

Casting and heat treatment variables of Al–7Si–Mg alloy

A review of the research work that has been carried out thus far relating the casting and heat treatment variables to the structure and mechanical properties of Al–7Si–Mg (wt-%) is presented here. Although specifications recommend a wide range of magnesium contents and a fairly high content of iron, a narrow range of magnesium contents, closer to either the upper or lower specified limits depending on the properties desired, and a low iron content will have to be maintained to obtain optimum and consistent mechanical properties. A few studies have revealed that the modification of eutectic silicon slightly increases ductility and fracture toughness and also that the effect of modification is predominant at low iron content. Generally, higher solidification rates give superior mechanical properties. Delayed aging (the time elapsed between quenching and artificial aging during precipitation hardening) severely affects the strength of the alloy. The mechanism of delayed aging can be explained on the basis of Pashley's kinetic model. It has been reported that certain trace additions (cadmium, indium, tin, etc.) neutralise the detrimental effect of delayed aging. In particular, it should be noted that delayed aging is not mentioned in any of the specifications. With reference to the mechanism by which trace additions neutralise the detrimental effect of delayed aging, various hypotheses have been postulated, of which impurity–vacancy interaction appears to be the most widely accepted.

Role of lipid peroxidation in impairment of mitochondrial function at complex I by methyl isocyanate treatment of rats in vivo

The subcutaneous administration of methyl isocyanate (MIC) in 1.0 LD50 dose in rats caused a significant effect on hepatic mitochondrial function only at complex I region of the respiratory chain. MIC administration at 1.0 LD50 dose also resulted in significant increases in malondialdehyde and ferrous ion concentration in liver mitochondria. It is suggested that the augmented lipid peroxidation in hepatic mitochondria, catalyzed by iron, possibly mobilized from intracellular stores leads to the inhibition of enzymes of mitochondrial respiration at complex I region, in vivo, in rats receiving a lethal dose of MIC subcutaneously.

Synthesis of Novel Oxide Pyrochlores, A2BB?O7 (A = La, Nd; BB? = Pb, Sn, Bi), by Alkali Melt Route

Oxide pyrochlores of the formula A2BB? O7 (A = La, Nd; BB? = Pb, Sn, Bi) have been synthesized by a low-temperature ambient-pressure route employing KOH melts. All the compositions, including La2Bi2O7 and its strontium-substituted derivatives, La2-xSrxBi2O7-?, are deeply colored insulators, confirming that a metallic ground state is not achieved for Pb(IV) and Bi(IV/V) oxides with the pyrochlore structure.

Growth of alkali metal periodates from silica gel and their characterization

Single crystals (up to 1 cm size) of K, Rb and Cs periodates have been grown in silica gel. In general, good quality crystals were obtained in gel of specific gravity 1.04 and pH 4. The metal/iodine ratios were determined and compared with calculated values. Morphological studies were carried out using a bicircle optical goniometer. Other characterization methods include X-ray diffraction, optical absorption, differential scanning calorimetry and optical microscopy. Microscopic examination of CsIO4 crystals in particular has revealed the existence of ferroelastic domains in the crystal. The structural basis for the occurence of ferroelasticity in this crystal is discussed and the high temperature space group is predicted.