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1.
Artigo em Inglês | MEDLINE | ID: mdl-32045211

RESUMO

Energy storage and conversion driven by electro- or photocatalyst is a highly exciting field of research, and generations of effective and durable oxide catalysts have received much attention in this field. Here, we report A-site lanthanum-doped oxygen-rich quinary oxide CaLaScRuO6+δ synthesized by adopting the solid-state reaction method and characterized by various techniques such as powder X-ray diffraction, neutron diffraction, energy-dispersive X-ray spectroscopy, inductively coupled plasma-atomic emission spectrometry, Raman spectroscopy, and temperature-programmed reduction in the presence of a hydrogen atmosphere (H2-TPR). X-ray absorption study confirms the existence of mixed valent Ru ions in the structure, which enhances the oxygen stoichiometry for the partial balance of an extra cationic charge. Neutron powder diffraction and reduction of the material in a hydrogen atmosphere (H2-TPR) can confirm the oxygen overstoichiometry of the catalyst. The present material works as an efficient and robust oxygen bifunctional electrocatalyst for ORR/OER (oxygen evolution reaction/oxygen reduction reaction) followed by four-electron transfer pathway in a strong (1 M KOH) alkaline medium. The catalytic nature of the designed structural and chemical flexible perovskite is a novel example of an electrocatalyst for the oxygen bifunctional activity.

2.
Atherosclerosis ; 295: 38-44, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32004823

RESUMO

BACKGROUND AND AIMS: The effect of nephrotic syndrome (NS) and its treatment on endothelial dysfunction is not evident. This study assessed endothelial dysfunction in adult-onset NS and its impact of immunosuppressive therapy. METHODS: Newly diagnosed patients with adult-onset NS (podocytopathy and primary membranous nephropathy (PMN)) and normal renal function were enrolled. Flow mediated vasodilatation (FMD) assessed endothelial function and CD4+CD28null T cells, E-selectin and pulse wave velocities (PWV) were measured at baseline and after treatment to characterize this further. Monitoring included monthly proteinuria, serum albumin, creatinine and lipid profile at baseline and post-treatment. The healthy control (HC) included 25 voluntary kidney donors who were assessed for markers of endothelial dysfunction. RESULTS: Fifty participants with new-onset NS were studied. Amongst the NS group, 26 (52%) patients had PMN, while the remaining 24 (48%) had podocytopathy. Twenty-one (88%) patients in the podocytopathy and 18 (69%) patients in the PMN cohort were in either complete or partial remission at the end of 8 months. FMD at baseline in NS patients was significantly lower as compared to HC (p = 0.002) while PWV (p = 0.007), E-selectin (p < 0.001) and CD4+CD28null T cells (p = 0.003) were significantly higher as compared with HC. Following treatment with immunosuppressive medication, FMD increased from 3 to 8% (p < 0.001). PWV also improved from a baseline of 7.70 to 6.65 m/s (p = 0.001). At the end of 8 months, E-selectin decreased significantly from 127 to 82 ng/ml (p = 0.002) while the CD4+CD28null T cell population reduced from 5.20 to 3.70% (p = 0.032) of total CD4+ cells. In the PMN cohort, despite significant reduction, E-selectin and CD4+CD28null T cells at follow-up remained higher than in healthy controls. CONCLUSION: Immunosuppressive treatment contributes substantially to the improvement of endothelial dysfunction present at baseline in NS patients. Persistent subtle endothelial dysfunction remains in the sub-group of patients with PMN.

3.
Clin J Am Soc Nephrol ; 15(2): 191-199, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-32001488

RESUMO

BACKGROUND AND OBJECTIVES: Patient-reported outcomes have gained prominence in the management of chronic noncommunicable diseases. Measurement of health-related quality of life is being increasingly incorporated into medical decision making and health care delivery processes. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The Indian Chronic Kidney Disease Study is a prospective cohort of participants with mild to moderate CKD. Baseline health-related quality of life scores, determined by the standardized Kidney Disease Quality of Life 36 item instrument, are presented for the inception cohort (n=2919). Scores are presented on five subscales: mental component summary, physical component summary, burden, effect of kidney disease, and symptom and problems; each is scored 0-100. The associations of socioeconomic and clinical parameters with the five subscale scores and lower quality of life (defined as subscale score <1 SD of the sample mean) were examined. The main socioeconomic factors studied were sex, education, occupation, and income. The key medical factors studied were age, eGFR, diabetes, hypertension, and albuminuria. RESULTS: The mean (SD) subscale scores were physical component summary score, 43±9; mental component summary score, 48±10; burden, 61±33; effects, 87±13; and symptoms, 90±20. Among the socioeconomic variables, women, lower education, and lower income were negatively associated with reduced scores across all subscales. For instance, the respective ß-coefficients (SD) for association with the physical component summary subscale were -2.6 (-3.4 to -1.8), -1.5 (-2.2 to -0.7), and -1.6 (-2.7 to -0.5). Medical factors had inconsistent or no association with subscale scores. The quality of life scores also displayed regional variations. CONCLUSIONS: In this first of its kind analysis from India, predominantly socioeconomic factors were associated with quality of life scores in patients with CKD.

4.
Chemistry ; 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31916272

RESUMO

The design of porous materials for the recognition of multiple hydrocarbons is highly desirable for the energy-efficient separation and recognition of chemical feedstock. Herein, three new iso-structural porous discrete metal-organic cages of formula {[Pd3 (NiPr)3 PO]4 (R-AN)6 } (R-AN=anilate linkers) for the selective recognition of substituted aromatic hydrocarbons are reported. The tetrahedral cages 1, 2, and 3 containing anilate, chloranilate, and bromanilate linkers exhibited selective encapsulation of mesitylene, o-xylene, and p-xylene, respectively, over other analogous aromatic hydrocarbons. These selective encapsulations were driven by the variations in the portal diameters present at each of these cages and their interactions with the hydrocarbon guests. These observations are supported by mass spectrometry, NMR studies, and theoretical binding-energy calculations.

5.
Mol Biol Rep ; 47(1): 533-544, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31724125

RESUMO

In the present investigation, we report cloning, expression, purification and characterization of a novel Bleomycin Resistance Dioxygenase (BRPD). His-tagged fusion protein was purified to homogeneity using Ni-NTA affinity chromatography, yielding 1.2 mg of BRPD with specific activity of 6.25 U mg-1 from 600 ml of E. coli culture. Purified enzyme was a dimer with molecular weight ~ 26 kDa in SDS-PAGE and ~ 73 kDa in native PAGE analysis. The protein catalyzed breakdown of hydrocarbon substrates, including catechol and hydroquinone, in the presence of metal ions, as characterized via spectrophotometric analysis of the enzymatic reactions. Bleomycin binding was proven using the EMSA gel retardation assay, and the putative bleomycin binding site was further determined by in silico analysis. Molecular dynamic simulations revealed that BRPD attains octahedral configuration in the presence of Fe2+ ion, forming six co-ordinate complexes to degrade hydroquinone-like molecules. In contrary, in the presence of Zn2+ ion BRPD adopts tetrahedral configuration, which enables degradation of catechol-like molecules.

6.
J Hazard Mater ; 384: 121353, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31611018

RESUMO

Phosphoramide functionalized Fe3O4 nanoparticles (NPs) were synthesized by a three step procedure and its application for uranium extraction from different enviornmental matrices has been demonstrated. A maximum adsorption capacity of 95.2 mg of U/g of the sorbent has been achieved which is higher as compared to many reported magnetic NPs. pH dependent adsorption studies were performed at 1 ppm uranium concentrations which suggests more than 80% adsorption in pH range of 4-8 with maximum adsorption at pH 6. Interestingly this is the pH range of most naturally occurring water bodies suggesting the potential of this material to extract uranium from real environmental samples. Adsorption studies were carried out with tap water, drinking water and sea water and more than 90% uranium extraction was observed. Desorption studies were performed with different reagents suggesting that the material can be reused again. EXAFS studies have been carried out which suggests that the uranium binds with oxygens of three PO group at the surface of phosphoramide functionalized NPs and based on this, binding mode of uranium with the synthesized sorbent is proposed.

7.
Inorg Chem ; 58(21): 14885-14899, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31609594

RESUMO

A multiple diglycolamide (DGA)-containing ligand having four DGA arms tethered to a tetraaza-12-crown-4 ring, viz. 2,2',2'',2'''-(((1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrayl)tetrakis(2-oxoethane-2,1-diyl)) tetrakis (oxy)) tetrakis(N,N-dioctylacetamide) (T12C4ODGA), was synthesized and evaluated for the extraction of different actinide and lanthanide ions, viz. Am3+, Eu3+, Pu4+, Np4+, and UO22+. The extraction efficiency of the present ligand was found to be the highest reported so far, more specifically for the trivalent metal ions Am3+ and Eu3+, when one considers the very low ligand concentration used in the present study, compared to that of the various previously reported multiple DGA-based ligands. The nature of the complexes formed during the extraction of Eu3+ was investigated using time-resolved fluorescence (TRFS) and extended X-ray absorption fine structure (EXAFS) spectroscopy. Both the solvent extraction and TRFS studies indicated the presence of 1:1 and 1:2 complexes during the extraction of Am3+ and Eu3+ having three inner-sphere water molecules in the 1:1 complex. Density functional theoretical (DFT) studies were performed on the Am3+ and Eu3+ complexes of both T12C4ODGA and an analogous compound having methyl groups in place of the n-octyl groups, and the DFT results of the T12C4ODGA nicely explain the extraction behavior of Am3+ and Eu3+.

8.
Chem Commun (Camb) ; 55(87): 13156-13159, 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31617513

RESUMO

A self-assembled M6L8 type cage-connected 1D-coordination network of formula {[Ni6(MeSi(3py)3)8Cl9(H2O)2]Cl3·16H2O}∞ (1) was obtained from a 3-pyridyl substituted silane ligand MeSi(3py)3. This complex shows significantly high performance for the electrocatalytic and photocatalytic hydrogen evolution reaction (HER) in water. A maximum turnover number (TON) of 2824 has been observed for photocatalytic HER after 69 h.

9.
Phys Chem Chem Phys ; 21(36): 20463-20477, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31502609

RESUMO

The Burstein-Moss (B-M) effect, which suggests that the optical band gap of degenerately doped semiconductors increases when all states close to the conduction band get populated due to shifting of an absorption edge to higher energy, is important, as it gives a chance to obtain different optical properties for the same material. Here, we report our observations of the similar shift in the optical band gap in NixFe2-xO3 nanocomposites as a function of composition with the help of cyclic voltammetry (CV) and XPS valence band (VB) position measurements. The conduction band edge (CBE) position of the NixFe2-xO3 nanocomposites as determined using CV was noted to move towards more negative potential with increasing Ni-concentration. A similar shift is also noted in the CBE estimated using XPS measurements (by subtracting the VB position from the optical band gap values). The observed shift in the optical band gap along with the CBE position gives the corresponding shift in the Fermi level, which is found to move closer to the CBE position, suggesting the observation of an effect similar to the B-M shift. Also, the extent of band bending estimated from the deviation of the CBE from the flat band potential (measured through Mott-Schottky plots) is found to increase with increasing Ni-concentration. Moreover, the Ni-composition has been observed to enhance the current density as well as to facilitate water splitting at a much lower onset potential compared to pure hematite. The NixFe2-xO3 nanocomposite with an 11 mol% Ni-composition shows the highest photo-electrochemical response with an almost ten times enhancement in the current density at 1.9 V vs. RHE in alkaline medium, as compared to the dark current. This enhanced performance is attributed to the improved charge separation and higher charge carrier density as a result of the higher extent of band bending in the NixFe2-xO3 nanocomposites.

10.
Chem Commun (Camb) ; 55(65): 9610-9613, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31317974

RESUMO

Traditionally, lead and heavy metal containing inorganic oxides dominate the area of ferroelectricity. Although, recently, lightweight non-toxic organic ferroelectrics have emerged as excellent alternatives, achieving higher temperature up to which the ferroelectric phase can persist has remained a challenge. Moreover, only a few of those are single-component molecular ferroelectrics and were discovered upon revisiting their crystal structures. Here we report a novel phenanthroimidazole derivative, which not only displays notable spontaneous and highly stable remnant polarizations with a low coercive field but also retains its ferroelectric phase up to a record-high temperature of ∼521 K. Subsequently, the crystal undergoes phase transition to form non-polar and centrosymmetric polymorphs, the first study of its kind in a single-component ferroelectric crystal. Moreover, the compound exhibits a significantly high thermal stability. Given the excellent figures-of-merit for ferroelectricity, this material is likely to find potential applications in microelectronic devices pertaining to non-volatile memory.

11.
J Family Med Prim Care ; 8(3): 853-859, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31041213

RESUMO

Background: Alcohol use remains a major cause of preventable death worldwide occurring prematurely. Despite its global burden, alcohol still is a legal drug. Various studies have also shown that factors like education, occupation, influence from films and family, for stress relief, pleasure during alcohol use, better self-esteem, and occupational boredom are associated with alcohol use. The consumption of alcohol, even in relatively small amounts, increases the risk of being involved in a crash for motorists and pedestrians. It is also associated with impaired judgments and so is often linked to road traffic accident. Objectives: To assess the prevalence, type of alcohol use, and the associated factors for the initiation of alcohol use among bus drivers and staffs of long route bus of Dharan. To assess the knowledge, attitude, and practice regarding alcohol use for their willingness to quit it with medical help. Materials and Methods: The cross-sectional survey was conducted in 250 long route drivers and staffs in Dharan Bus Park in 2016 with the help of a self-designed questionnaire in Nepali language. The sample size was preliminarily estimated on the basis of the prevalence of alcohol use. The "Alcohol consumer" refers to drivers who used alcohol at least once in the previous year. Results: Alcohol dependency among Hindu was found to be significantly more than other religious group. The prevalence of alcohol consumption was found to be 78%. About 51% drivers are likely to have alcohol problems, 39% are alcohol abuser, and 45% are alcohol dependent. Conclusion: Drinking and driving increase the vulnerability to injury and death on the road. The study creates awareness among drivers about the harmful use of alcohol and psychosocial consequences.

12.
Kidney Int Rep ; 4(3): 420-424, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30899869

RESUMO

Introduction: Pregnancy-related acute kidney injury is the most common cause of renal cortical necrosis (RCN). Atypical hemolytic uremic syndrome (aHUS) as a cause of RCN in pregnant/postpartum is underevaluated. In the current article, we describe a series of cases of pregnancy-related RCN. Methods: All cases with acute kidney injury (AKI) in the setting of pregnancy and postpartum state were included. Diagnosis of RCN was made by contrast-enhanced computerized tomography (nonenhancing renal cortex, enhancing medulla, and no excretion of contrast medium) or on a renal biopsy. aHUS was diagnosed in the presence of microangiopathic hemolytic anemia (thrombocytopenia, elevated lactate dehydrogenase with schistocytes on peripheral smear examination, or low haptoglobin). Results: A total of 21 (17.5%) patients presented with RCN during pregnancy, all in the postpartum state. Twenty patients (95.2%) showed microangiopathic hemolytic anemia consistent with HUS and 1 (4.8%) patient had biopsy-proven thrombotic microangiopathy. Low complement 3 or activation of an alternate complement pathway was seen in 9 of 15 patients in which it was done. At the end of 6 months, only 2 (9.5%) patients had partial recovery of renal functions, 5 (23.8%) patients died, and 14 remained (66.7%) on hemodialysis. Conclusion: The clinical and laboratory features are highly suggestive of aHUS in more than three-fourths of cases with postpartum RCN. Investigations are needed to look for genetic abnormalities in the complement pathway.

13.
Int Urol Nephrol ; 51(1): 181-186, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30456544

RESUMO

PURPOSE: CKD patients after kidney transplantation continue to suffer from elevated CV events which may be related to low vitamin D and its adverse impact on vascular function. The prevalence of vitamin D deficiency in North Indian kidney transplantation patients and its impact on vascular and bone biomarkers is unknown which this study investigated. METHODS: Non-diabetic, stable, > 6 months post-kidney transplantation patients, not on vitamin D supplementation, were recruited after informed consent. Data on demographics, anthropometrics and treatment were collected. Blood samples were stored at - 80 °C until analysis for bone and endothelial cell biomarkers using standard ELISA techniques. RESULTS: The clinical characteristics were: age 37.4 ± 9.9 years, 80% men, 27% ex-smokers, BP 125.5 ± 15.7/78.6 ± 9.7 mmHg, cholesterol 172.0 ± 47.8 mg/dL, hemoglobin 12.6 ± 2.3 g/dL, calcium 9.5 ± 0.6 mg/d and iPTH 58.4 ± 32.9 ng/mL and vitamin D 36.5 ± 39.8 nmol/L. Patients with vitamin D < 37.5 nmol/L (66%) had similar age, serum creatinine, serum phosphate, iPTH, blood pressure but lower calcium (9.3 ± 0.7 vs. 9.6 ± 0.5 mg/dL; p = 0.024), lower FGF23 (median 18.8 vs. 80.0 pg/mL; p = 0.013) and higher E-selectin (15.8 ± 7.9 vs. 13.0 ± 5.5 ng/mL; p = 0.047). On Univariate analysis, E-selectin (r = - 0.292; p = 0.005), FGF23 (r = 0.217; p = 0.036) and calcium (r = 0.238; p = 0.022) were significantly correlated with vitamin D levels. On stepwise multiple regression analysis, only E-selectin was associated with vitamin D levels (ß = - 0.324; p = 0.002). CONCLUSION: Vitamin D deficiency was common in kidney transplant recipients in North India, associated with low FGF23 and high E-selectin. These findings suggest further investigations to assess the role of vitamin D deficiency-associated endothelial dysfunction, its implications and reversibility in kidney transplantation recipients.


Assuntos
Selectina E/sangue , Endotélio Vascular , Fatores de Crescimento de Fibroblastos/sangue , Falência Renal Crônica , Transplante de Rim , Doenças Vasculares , Deficiência de Vitamina D , Adulto , Biomarcadores/sangue , Estudos Transversais , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiopatologia , Feminino , Humanos , Índia/epidemiologia , Falência Renal Crônica/sangue , Falência Renal Crônica/epidemiologia , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Transplante de Rim/métodos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Doenças Vasculares/diagnóstico , Doenças Vasculares/epidemiologia , Doenças Vasculares/metabolismo , Vitamina D/sangue , Deficiência de Vitamina D/diagnóstico , Deficiência de Vitamina D/epidemiologia
14.
J Clin Rheumatol ; 2019 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-31895109

RESUMO

OBJECTIVE: The aim of this study was to assess endothelial dysfunction in acute and convalescent phases of Kawasaki disease (KD) using automated edge detection software. METHODS: This was a case-control study to assess the flow-mediated dilatation (FMD) of brachial artery (BA) in patients with KD during acute phase and at least 3 months after diagnosis. A 10-MHz multifrequency linear array probe attached to a high-resolution ultrasound machine (PHILIPS Medical System-IU22) was used to acquire the images. Automated edge detection software was used to assess BA diameter. RESULTS: A total of 16 children with KD and 16 healthy children were enrolled in the study. Mean ± SD maximum BA diameter was found to be significantly low during the acute stage of KD (2.56 ± 0.36 mm) as compared with the convalescence phase (2.93 mm ± 0.31) and in healthy controls (2.95 mm ± 0.56). The mean ± SD percentage change in the FMD was found to be significantly low in the acute phase of KD (12.32 ± 6.2) as compared with the convalescence phase of KD (17.99 ± 8.13) and healthy controls (26.88 ± 12.76). The mean ± SD percentage change in the FMD was also found to be significantly low in the convalescence phase of KD as compared with healthy controls. CONCLUSIONS: The FMD of the BA is significantly reduced in patients during the acute and convalescence phase of KD as compared with normal healthy children. The endothelial dysfunction was present even in patients who had no obvious coronary artery abnormalities during the acute stage.

15.
JNMA J Nepal Med Assoc ; 57(219): 367-370, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32329467

RESUMO

INTRODUCTION: Patient satisfaction is an important component of quality nursing care and is often determined by the nursing care in any health institution. The aim of the study is to find the presence of satisfaction among in-ward patients of five major wards at a tertiary care hospital regarding the quality of care provided by nursing staff. METHODS: A descriptive cross-sectional study was conducted among 105 patients of Patan Hospital from 3rd July to 3rd August, 2015 after obtaining ethical clearance from Institutional Review Committee. Sample size was calculated and stratified random sampling was done. Data was collected in Microsoft Excel and analyzed in Sta 13.0. Point estimate at 95% Confidence Interval was calculated and frequency and percentage was calculated for binary data. Subgroup analysis was done on the basis of demographic variables. RESULTS: Among 105 patients, 99 (94.3%) [94.93-95.07 at 95%CI] were satisfied with the nursing care provided at a tertiary care center in Nepal. Among them, 60 (60.6%) were females and 39 (39.4%) were males. Age of the patients ranged from 1 year to 85 years. The length of the stay in the hospital ranged from 2 to 17 days (mean = 5.6 days). CONCLUSIONS: Most of the patients were satisfied with the nursing care provided in a tertiary care centre. Routine nursing care surveys and immediate feedbacks would keep the authorities updated and deliver good health care.

16.
Dalton Trans ; 47(42): 15164-15172, 2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-30311928

RESUMO

A generation 1 dendrimer, based on tris(2-aminoethyl)amine (TREN), containing six diglycolamide (DGA) pendent arms (termed TREN-G1-DGA) was synthesized and evaluated for the extraction of actinides and fission product ions. Solvent extraction studies indicated preferential extraction of Eu3+ over Am3+ with a separation factor value of ca. 4.5 in line with the extraction behaviour of multiple DGA ligands in previous reports. The distribution values of Am3+ and Eu3+ were about 12 and 9 times higher, respectively, than those obtained in the case of TREN-DGA using the 1 × 10-3 M ligand in 5% iso-decanol/95% n-dodecane at 3 M HNO3. The 1 : 1 (M : L) extracted species suggested 'inclusion' complex formation where more than one DGA moiety participates in the complex formation. The extracted species were devoid of any inner-sphere coordinated water molecules as confirmed by luminescence spectroscopy. The structure of the complex was also studied by DFT computations and EXAFS which suggested binding of three DGA arms around the central metal ion in the absence of any inner-sphere nitrate ions.

18.
Inorg Chem ; 57(20): 12987-12998, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30256631

RESUMO

A novel tripodal diglycolamide ligand containing a triazamacrocycle center (2,2',2''-(((1,4,7-triazonane-1,4,7-triyl)tris(2-oxoethane-2,1-diyl)) tris(oxy)) tris( N, N-dioctylacetamide), abbreviated as T9C3ODGA) was synthesized and characterized by conventional techniques. The ligand resulted in efficient extraction of actinide/lanthanide ions yielding the trend: Eu3+ > Pu4+ > Am3+ > NpO22+ > UO22+ > Sr2+ > Cs+. Similar to most of the other diglycolamide (DGA) ligands, Eu3+ was preferentially extracted as compared to Am3+; the separation factor ( DEu/ DAm) value at 3 M HNO3 was ca. 4.2. In contrast, separation from UO22+ ion was less effective as compared to that of other tripodal DGA ligands studied earlier. Solvent extraction studies indicated extraction of species of the ML2 (where L is T9C3ODGA) stoichiometry. The formation of an inclusion complex with no inner-sphere water molecule was confirmed from luminescence spectral studies. DFT computations predicted the presence of an inner-sphere nitrate ion in the most preferred complex, which was also supplemented by EXAFS and luminescence studies. The selectivity of T9C3ODGA could be explained on the basis of its more favorable interactions with Eu3+ as compared to those with Am3+ both in the gas and the solution phases.

19.
Environ Sci Pollut Res Int ; 25(32): 32312-32320, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30229489

RESUMO

In present study, biodiesel was produced from landfill waste-derived oil by chemical transesterification process, to evaluate its potential as a renewable energy source for the first time. The free fatty acid percentage (FFA) in landfill waste oil is considered to be high, which was reduced by treating it with two different acids as catalyst, muriatic acid and phosphoric acid, in order to build a comparison between fatty acid methyl ester (FAME) contents. Further, it was treated with a base catalyst potassium hydroxide (KOH) to produce the final product. The FAME value of landfill oil when treated with muriatic acid was found to be 92.59%. The quality of biodiesel produced was analyzed by gas chromatography (GC), which indicated above 25.7% of conversion of oil into biodiesel when muriatic acid was used as a catalyst. The properties of the produced biodiesel were found to be in good agreement with ASTM D 6751 and EN 14214 standards. Various test fuels were prepared for the engine test by blending 10%, 20%, and 100% of landfill waste biodiesel in diesel on volumetric basis and designated as B10, B20, and B100, respectively. The brake thermal efficiency (BTE) of the engine was more while the exhaust emission was less except NOx with biodiesel and its blend (B10 and B20). Thus, landfill waste is a potential source of biodiesel, and blends of landfill waste up to 20% can be used for realizing better performance from the engine.


Assuntos
Biocombustíveis , Ácidos Graxos não Esterificados/química , Instalações de Eliminação de Resíduos , Águas Residuárias/química , Catálise , Cromatografia Gasosa , Esterificação , Ácidos Graxos , Emissões de Veículos/análise
20.
Chemistry ; 24(55): 14639-14643, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30063810

RESUMO

Designing molecular crystals with switchable dipoles for ferroelectric applications is challenging and often serendipitous. Herein, we show a systematic approach toward hierarchical 1D, 2D and 3D frameworks that are assembled through successive linkage of metal-organic cages [Cu6 (H2 O)12 (TPTA)8 ]12+ with chloride ions. Their ferroelectric properties are due to the displacement of channel-bound nitrate counterions and solvated water molecules relative to the framework of cages. Ferroelectric measurements of crystals of discrete and 1D-framework assemblies showed axial ferroelectric anisotropy with high remnant polarisation. Both, the reversible formation of cage-connected networks and the observation of ferroelectric anisotropic behaviour are rare among metal-ligand cage assemblies.

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