Highlights
Eugenol (4-allyl-2-methoxyphenol) extracted from
O. sanctum
leaves is used as a natural reducing agent for the synthesis of CuO nanoflowers (NFs).
CuO-NFs can degrade methylene blue with ...an efficiency of 90%.
CuO-NFs offer a new vision to deactivate multi-drug microorganisms.
Copper oxide nanoflowers (CuO-NFs) have been synthesized through a novel green route using Tulsi leaves-extracted eugenol (4-allyl-2-methoxyphenol) as reducing agent. Characterizations results reveal the growth of crystalline single-phase CuO-NFs with monoclinic structure. The prepared CuO-NFs can effectively degrade methylene blue with 90% efficiency. They also show strong barrier against
E
.
coli
(27 ± 2 mm) at the concentration of 100 µg mL
−1
, while at the concentration of 25 µg mL
−1
weak barrier has been found against all examined bacterial organisms. The results provide important evidence that CuO-NFs have sustainable performance in methylene blue degradation as well as bacterial organisms.
In the present paper, we report a detailed study on the sodium (Na) doping-induced modifications in the copper oxide (CuO) nanostructure and its properties. A facile and sustainable sol–gel synthesis ...approach was employed for the preparation of high-quality pristine CuO- and Na-doped CuO nanostructures(1.0, 3.0, 5.0 and 7.0 mol% doping levels, CuO/Na) with controlled shape and composition. Due to the remarkable difference in the ionic radii of Cu
2+
(0.73 Å) and Na
+
(1.02 Å), Na
+
substitution in place of Cu
2+
generates strain/distortions in CuO lattice. The XRD analysis reveal the structural alteration from monoclinic to cubic symmetry with increase in doping level and also reveal the phase purity up to 3% doping level, and beyond this (i.e., for 5 and 7% doping level) small amount of impurity phase corresponding to Na
2
O was observed. The FTIR results further confirmed the presence of the Na–Cu–O stretching vibrations at higher Na-doped samples. Morphology of the samples indicates that the Na-doped CuO nanostructures exhibit less agglomeration compared to pristine CuO nanoparticles. The presence of Na in CuO lattice were found to greatly enhances optical and electrical properties owing to the formation of defects like copper vacancies and oxygen vacancies at the grain boundaries of the nanoparticles with increased doping of Na.
How high can public debt rise without compromising fiscal solvency? We answer this question using a stochastic model of sovereign default in which risk-neutral investors lend to a government that ...displays 'fiscal fatigue', whereby its ability to increase primary balances cannot keep pace with rising debt. As a result, the government faces an endogenous debt limit beyond which debt cannot be rolled over. Using data for 23 advanced economies over the period 1970—2007, we find evidence of a fiscal reaction function with these features, and use it to compute 'fiscal space', defined as the difference between current debt ratios and the estimated debt limits.
•The workability of the composite is reduced by GO while rGO has minor impact.•GO accelerated cement hydration while rGO have more impact in the C3A phase hydration.•GO increased higher content of CH ...and C-S-H in the composite micropores compared to rGO.•Flexural strength improvement in the GO composite is higher than the rGO composite.•Both GO and rGO improved the transport properties of the composites.
This study examines and compares the performance of two specific forms of graphene nanomaterials in the cement based composite, namely graphene oxide (GO) and reduced graphene oxide (rGO). A typical forms of GO with the average C:O ratio of 54:46 and a rGO with the average C:O ratio of 82:18 were used in the cement based paste composites. rGO was treated with superplasticizer to improve its dispersibility in water. Both GO and rGO were used as 0.02, 0.04, 0.06 wt% of cement. The effect of GO and rGO on workability, early age hydration, microstructure, mechanical and transport properties was determined. Different characteristics of GO and rGO such as molecular structure, functional groups, d spacing, size and physical strength influenced the properties of the cement based composites. The workability and final setting time of composite gradually decreased compared to 100% PC (control) with higher dosages of GO up to 0.06 wt% (of cement), which is due to the dominant oxygen functional groups and the hydrophilic nature of GO. To the contrary, the workability and final setting time increased in the rGO composites compared to the control mix due to the almost hydrophobic nature of rGO and the presence of superplasticiser. The XRD and TGA quantification of the hydration products shows that GO composites have a greater content of Ca(OH)2 and C-S-H compared to rGO composites measured at 1, 7 and 28 days. Micropores (smaller than ∼10 µm) in GO composites were observed to be filled with calcium silicate hydrate (C-S-H) gel and crystalline compounds. Random pore filling nature was observed in rGO composites and ettringite was more common element in those pores. Meso and gel pores (<2 nm) related to C-S-H show increasing trend in the GO and rGO composites compared to the control mix in dynamic vapour sorption (DVS) analysis. Compared to the control mix, the 28-day compressive strength increased by ∼10% and ∼15% in 0.06 wt% of GO and rGO in the composites. However, the highest flexural strength was increased in the 0.04 wt% of GO and 0.06 wt% rGO composite, and the enhancement was 75.7% and 33.7%, respectively, compared to the control mix. The electrical resistivity value increased with the incorporation of GO and rGO. The water sorptivity coefficient of 28-day GO and rGO composite reduced 24.8% and 4.7%, respectively, compared to the control mix.
We examine whether macroprudential policies and capital controls can enhance financial stability in the face of the risks typically associated with large capital inflows. We construct new indices of ...foreign currency (FX)-related prudential measures, domestic prudential measures, and financial-sector specific capital controls for 51 emerging market economies over the period 1995–2008. Our results indicate that both capital controls and FX-related prudential measures are associated with a lower proportion of FX lending in total domestic bank credit, and with a lower proportion of portfolio debt in total external liabilities. Other prudential policies appear to help restrain the intensity of aggregate credit booms. Experience from the global financial crisis suggests that prudential and capital control policies in place during the boom enhanced economic resilience during the bust.
► We create new indices of financial sector prudential measures and capital controls. ► Capital controls and FX-related measures reduce FX lending by domestic banks. ► They also reduce the share of portfolio debt in total external liabilities. ► Other prudential measures help restrain aggregate credit booms. ► Overall, these various measures enhance the economy's resilience to financial crisis.
Cytotoxic T lymphocyte antigen 4 (CTLA-4) is an essential negative regulator of T cell immune responses whose mechanism of action is the subject of debate. CTLA-4 shares two ligands (CD80 and CD86) ...with a stimulatory receptor, CD28. Here, we show that CTLA-4 can capture its ligands from opposing cells by a process of trans-endocytosis. After removal, these costimulatory ligands are degraded inside CTLA-4—expressing cells, resulting in impaired costimulation via CD28. Acquisition of CD86 from antigen-presenting cells is stimulated by T cell receptor engagement and observed in vitro and in vivo. These data reveal a mechanism of immune regulation in which CTLA-4 acts as an effector molecule to inhibit CD28 costimulation by the cell-extrinsic depletion of ligands, accounting for many of the known features of the CD28—CTLA-4 system.
Background
There is uncertainty regarding the safety of different volume replacement solutions. The aim of this study was systematically to review evidence of crystalloid versus colloid solutions, ...and to determine whether these results are influenced by trial design or clinical setting.
Methods
PubMed, Embase and the Cochrane Central Register of Controlled Trials were used to identify randomized clinical trials (RCTs) that compared crystalloids with colloids as volume replacement solutions in patients with traumatic injuries, those undergoing surgery and in critically ill patients. Adjusted odds ratios (ORs) for mortality and major morbidity including renal injury were pooled using fixed‐effect and random‐effects models.
Results
Some 59 RCTs involving 16 889 patients were included in the analysis. Forty‐one studies (69 per cent) were found to have selection, detection or performance bias. Colloid administration did not lead to increased mortality (32 trials, 16 647 patients; OR 0·99, 95 per cent c.i. 0·92 to 1·06), but did increase the risk of developing acute kidney injury requiring renal replacement therapy (9 trials, 11 648 patients; OR 1·35, 1·17 to 1·57). Sensitivity analyses that excluded small and low‐quality studies did not substantially alter these results. Subgroup analyses by type of colloid showed that increased mortality and renal replacement therapy were associated with use of pentastarch, and increased risk of renal injury and renal replacement therapy with use of tetrastarch. Subgroup analysis indicated that the risks of mortality and renal injury attributable to colloids were observed only in critically ill patients with sepsis.
Conclusion
Current general restrictions on the use of colloid solutions are not supported by evidence.
Some colloids are nephrotoxic in patients with sepsis
In recent years, various novel and greener methodologies have been developed using ionic liquids (ILs). In these reactions, IL has played multiple roles like catalyst, solvent, and catalyst support. ...In some cases, it was observed that IL enables efficient catalytic reactions in comparison with conventional molecular solvents. On the other hand, although a number of catalytic reaction processes in which ILs are used have been established in industry, there were also some unexpected problems, such as unintelligible aberrance or degradation of so-called task-specific ILs occurring in reaction processes and on the pilot plant scale. Also, several urgent questions regarding the fundamental aspects of ILs particularly toxicity and greener preparation methods need to be clarified. Several industrial applications of ILs are also discussed.
The aim of the study was to study the clinical and histological features of Alagille syndrome (AGS) at presentation comparing the value of the various modalities before the implementation of genetic ...diagnosis.
We performed a retrospective analysis of the records of 117 children diagnosed as having AGS after referral to King's College Hospital between 1980 and 2005.
Cholestasis was seen in 104 of 117 (89%), characteristic facies in 91 of 117 (77%), posterior embryotoxon in 72 of 117 (61%), butterfly vertebrae in 44 of 117 (39%), heart disease (most often peripheral pulmonary stenosis) in 107 of 117 (91%), and renal disease in 27 of 117 (23%). Serum cholesterol levels of >5 mmol/L were seen in 52 of 86 (60.4%). Liver biopsy showed characteristic features of paucity of interlobular bile ducts in 59 of 77 (76.6%) children younger than 16 weeks of age, in 10 of 14 (71.4%) between 16 weeks and 1 year of age, and in 8 of 12 (66.66%) older than 1 year of age. Other biopsy findings were those of nonspecific hepatitis and biliary features. Iminodiacetic acid scans showed no excretion of isotope into the bowel after 24 hours in 21 of 35 (60%), and small/no gallbladder on ultrasound was seen in 29 of 104 (27.8%). Eleven of 117 (9.4%) had a diagnostic laparotomy and operative cholangiography, 2 proceeding to Kasai portoenterostomy before referral to our unit.
Clinical features of AGS are not as consistently informative as suggested in the literature. Hypercholesterolaemia is nonspecific but may be a helpful pointer. Histology is not characteristic in 25%; hepatobiliary iminodiacetic acid scan and ultrasound may suggest a false diagnosis of biliary atresia in 60% and 28%, respectively, supporting the concept that infants with liver disease warrant early referral to a specialist centre. The advent of genetic diagnosis will redefine the syndrome with likely effects on the prognosis of the defined group.
We investigate the electronic transport properties of silicon carbide nanotubes (SiCNT) in presence of both boron (B) and nitrogen (N) impurities. The results show that co-doping BN impurities ...suppresses the important negative differential resistance (NDR) property. NDR suppression is attributed to the introduction of new electronic states near the Fermi level followed by weak orbital localization. BN co-doping results in exponential current–voltage (I–V) characteristics which is in contrast to linear I–V characteristics for individual boron and nitrogen doped SiCNTs. HOMO has no contribution from B impurity, whereas, LUMO has contribution from N impurity at low and high bias.
► BN co-doping suppresses the negative differential resistance property of SiCNT. ► HOMO has no contribution from BN impurity. ► LUMO is contributed from nitrogen atoms at low and high bias voltages. ► BN co-doping results in exponential increase in current with bias. ► Rectification is negligible.
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