Java plum leaves ash (JLA) was prepared by calcination (400 °C) to remove cationic dyes Methylene blue dye (MBD), Acridine orange dye (AOD), and Crystal violet dye (CVD) from aqueous solutions. ...Multiple physiochemical and microanalytical methods, including SEM, EDX, FTIR, TGA and XRD, were used to characterize JLA. This research aims to investigate the viability of JLA as a novel adsorbent and the mechanism of its adsorption for cationic dyes. In addition, the effects of solution pH, various dye concentrations, adsorbent dosages, stirring speed, and adsorption time on JLA adsorption performance are studied. The adsorption analyses showed that the maximum adsorption capacities of MBD, AOD, and CVD are 75.87, 110.37, and 92.33 mg/g, respectively. This is much greater than other adsorbates described in the literature, suggesting the viability of JLA as a novel adsorbent within 20–60 min of contact time from an initial 100 mg/L dye solution with a dosage of 0.1 g/ml adsorbent at pH 6 and room temperature. The Langmuir isotherm, Freundlich isotherm, and Temkin isotherm models most accurately represent adsorption behaviour.
Two conformational polymorphs of 5-methyl-2-(2-nitrophenyl)amino-3-thiophenecarbonitrile (ROY) exhibited similar morphology but strikingly different mechanical flexibility, where the yellow needle ...(YN) is exceptionally elastic while orange needle (ON) is highly brittle. Similar to color differentiation, the distinct bending behaviors of YN and ON polymorphs are linked to different molecular conformations. Aided by crystal structural analysis, interaction energies, topology, nanoindentation, and elastic constant calculation, this study reveals new structural insights that explain the strikingly different mechanical behaviors of the two polymorphs.
The growing incidence of chronic kidney disease remains a global health problem. Obesity is a major risk factor for type-2 diabetes and renal impairment. Perirenal adiposity, by virtue of its ...anatomical proximity to the kidneys may cause kidney disease through paracrine mechanisms that include increased production of inflammatory cytokines. Although heme-oxygenase (HO) is cytoprotective, its effects on perirenal adiposity and diabetic nephropathy in Zucker-diabetic fatty rats (ZDFs) remains largely unclear. Upregulating the HO-system with hemin normalised glycemia, reduced perirenal adiposity and suppressed several pro-inflammatory/oxidative mediators in perirenal fat including macrophage-inflammatory-protein-1α (MIP-1α), endothelin (ET-1), 8-isoprostane, TNF-α, IL-6 and IL-1β. Furthermore, hemin reduced ED1, a marker of pro-inflammatory macrophage-M1-phenotype, but interestingly, enhanced markers associated with anti-inflammatory M2-phenotype such as ED2, CD206 and IL-10, suggesting that hemin selectively modulates macrophage polarization towards the anti-inflammatory M2-phenotype. These effects were accompanied by increased adiponectin, HO-1, HO-activity, atrial-natriuretic peptide (ANP), and its surrogate marker, urinary-cGMP. Furthermore, hemin reduced renal histological lesions and abated pro-fibrotic/extracellular-matrix proteins like collagen and fibronectin that deplete nephrin, an important transmembrane protein which forms the scaffolding of the podocyte slit-diaphragm allowing ions to filter but not massive excretion of proteins, hence proteinuria. Correspondingly, hemin increased nephrin expression in ZDFs, reduced markers of renal damage including, albuminuria/proteinuria, but increased creatinine-clearance, suggesting improved renal function. Conversely, the HO-blocker, stannous-mesoporphyrin nullified the hemin effects, aggravating glucose metabolism, and exacerbating renal injury and function. The hemin effects were less-pronounced in Zucker-lean controls with healthy status, suggesting greater selectivity of HO in ZDFs with disease. We conclude that the concomitant reduction of pro-inflammatory/oxidative mediators, macrophage infiltration and profibrotic/extracellular-matrix proteins, coupled to increased nephrin, adiponectin, ANP, cGMP and creatinine clearance may account for improved renal function in hemin-treated ZDFs. These findings suggest that HO-inducers like hemin may be explored against the co-morbidity of perirenal adiposity and diabetic nephropathy.
The MCM-41 and Al grafted MCM-41 (Si/Al=20) showed excellent catalytic activity in amine (1) activation for oxidative self and cross coupling to synthesize imines (2 or 2′). The presence of Al, its ...amount, catalyst acidity, reaction conditions and amines nature influencethe reactions.
•Excellent activity of MCM-41 and Al-MCM-41 for oxidative coupling of amines.•Presence of Al, its amount, catalyst acidity, solvent and air affect the reaction.•Surface OH groups activate amines by hydrogen bonding for coupling reaction.•Acid sites generated by optimum amount of Al improve catalytic activity.•Amines nature (basicity and nucleophilicity) influences catalysts activity.
The catalytic activity of MCM-41 mesoporous silica (MS) and Al grafted MCM-41 (Al-MS) with varied amount of Al were studied for oxidative self and cross coupling of benzyl amines to imines. The role of Al, its amount, acidity of the catalyst, effect of reaction conditions (especially presence of solvent and excess air) and amines nature on the oxidative coupling reactions were investigated. Surface OH groups play an effective role in amine activation by hydrogen bonding, whereas the acid sites generated by incorporation of optimum amount of Al further improve the activity. The Al in optimum amount (Si/Al: 20) showed good catalytic activity in self coupling of benzyl amine as compared to MS and Al-MS with high Al loading. A suitable polar solvent and presence of excess air significantly promote the activity of MS and Al-MS for amine coupling reactions. The MS without Al was also found to be efficient catalyst for oxidative self and cross coupling of amines. The presence of Al in Al-MS (in optimum amount, i.e., Si/Al: 20) made the self coupling of benzyl amine faster than MS, whereas the cross coupling reactions with Al-MS were observed to be slightly slower than MS, which is probably due to competitive adsorption of amine substrate and amine nucleophile over acidic sites. The activity of MS and Al-MS catalysts for self and cross coupling reactions was also dependent of the amines nature (basicity and nucleophilicity).
The catalytic activity of Mg–Al hydrotalcite supported copper catalyst was investigated for clean CC and CN bond forming reactions using alcohols as alkylating agent via borrowing hydrogen ...methodology. The catalyst showed excellent conversion of ketone and amine substrates (71–99%) to alkylated products with high selectivity in alkylation reactions.
The C-alkylation of carbonyls (2) and N-alkylation of amines (3) with alcohols (1) was carried out using Mg–Al hydrotalcite supported copper (Cu-HT) catalyst via clean borrowing hydrogen method. Display omitted
► Hydrotalcite supported copper (Cu-HT) showed potential of borrowing hydrogen. ► Solvent free and base free borrowing hydrogen methodology was established. ► C-alkylation of carbonyls and N-alkylation of amines with alcohols was carried out using Cu-HT. ► Primary, secondary and benzylic alcohols could be activated for borrowing hydrogen. ► Aromatic carbonyl and amine (deactivated substrates) showed good reactivity.
A simple strategy to fabricate carbon dots (CDs) incorporated organically modified silica (ORMOSIL) films exhibiting tunable tricolor emission has been accomplished. First, the green-emitting CDs ...with excitation-independent nature and high quantum yield were prepared from o-phenylenediamine in ethanol by solvothermal method. These CDs after purification were dispersed in ORMOSIL sol, and their photoluminescence wavelengths were tuned to three intense luminescent colors (orange, yellow, and green) by adjusting the pH of the sol. It was observed that with pH tuning the functional groups residing on surface-passivated CDs are undergoing chemical modifications, and accordingly the PL emission of CDs in ORMOSIL sol systematically changes to orange, yellow, and green emissions, respectively. Interestingly, the structure of such surface-modified CDs can be well-preserved in the ORMOSIL film-matrix with substantial concentration to obtain the above tricolor luminescent films on glass. A systematic X-ray photoelectron spectroscopy study revealed that the blue shifting in triluminous films (from 560 to 510 nm) with pH increment was originated due to the deprotonation of the surface groups (−CONH– → −CO(N–)–; −NH3 + → −NH2) associated with the CDs. The plausible mechanism behind the rationalization of pH-triggered engineering of surface-passivated CD-ORMOSIL sols and their confinement in films has been explored.
The silver-doped titanium dioxide (Ag–TiO2) photocatalysts with varied silver content ranging from 0.75 at % to 3.5 at % were synthesized by a single-step sol–gel method. The role of silver content ...on the properties of photocatalyst has been studied. The doping of 0.75 at % silver in TiO2 produced thermally stable TiO2 anatase phase with smallest particle size, uniform particles size and morphology, high surface area and low-energy excitation characteristics. The Ag–TiO2 sample with 0.75 at % silver possesses predominantly finely dispersed silver species (Ag2O and AgO) on the surface. The proportion of surface agglomerated silver metal (Ag0) increases as the silver content in the Ag–TiO2 sample increases. The silver oxide species were observed to be responsible for better physicochemical and catalytic properties. The TiO2 with 0.75 at % silver was found to be an efficient photocatalyst showing enhanced photocatalytic activity for aqueous medium photocatalytic degradation of phthalic acid in the presence of UV radiation and air.
The outcome of the disease visceral leishmaniasis (VL), caused by Leishmania donovani (LD), largely relies on the relative dominance of host-protective type-1 T helper (Th1) cell response versus ...disease-promoting type-2 T helper (Th2) cell response. The Th1 and Th2 responses, in turn, are believed to be elicited by type-1 conventional dendritic cells (cDC1) and type-2 conventional DCs (cDC2), respectively. However, it is still unknown which DC subtype (cDC1 or cDC2) predominates during chronic LD infection and the molecular mechanism governing such occurrence. Here we report that in chronically infected mice, the splenic cDC1-cDC2 balance shifted toward the cDC2 subtype and that the receptor T cell immunoglobulin and mucin protein-3 (TIM-3) expressed by DCs played a key role in mediating this effect. Transfer of TIM-3-silenced DCs in fact prevented the predominance of the cDC2 subtype in mice with chronic LD infection. We also found that LD actually upregulated TIM-3 expression on DCs by triggering a TIM-3-mediated signaling pathway STAT3 (signal transducer and activator of transcription 3)→interleukin (IL)-10→c-Src→transcription factors Ets1, Ets2, USF1, and USF2. Notably, TIM-3 promoted STAT3 activation via a non-receptor tyrosine kinase Btk. Adoptive transfer experiments further demonstrated a critical role for STAT3-driven TIM-3 upregulation on DCs in increasing cDC2 abundance in chronically infected mice, which ultimately aided disease pathogenesis by augmenting Th2 responses. These findings document a new immunoregulatory mechanism contributing to disease pathology during LD infection and define TIM-3 as a key mediator of this process.
Background: In October 2008, Centers for Medicare and Medicaid Services discontinued reimbursement for hospital-acquired pressure ulcers (HAPUs), thus placing stress on hospitals to prevent incidence ...of this costly condition. Objective: To evaluate whether prevention methods are cost-effective compared with standard care in the management of HAPUs. Research Design and Subjects: A semi-Markov model simulated the admission of patients to an acute care hospital from the time of admission through 1 year using the societal perspective. The model simulated health states that could potentially lead to an HAPU through either the practice of "prevention" or "standard care." Univariate sensitivity analyses, threshold analyses, and Bayesian multivariate probabilistic sensitivity analysis using 10,000 Monte Carlo simulations were conducted. Measures: Cost per quality-adjusted life-years (QALYs) gained for the prevention of HAPUs. Results: Prevention was cost saving and resulted in greater expected effectiveness compared with the standard care approach per hospitalization. The expected cost of prevention was $7276.35, and the expected effectiveness was 11.241 QALYs. The expected cost for standard care was $10,053.95, and the expected effectiveness was 9.342 QALYs. The multivariate probabilistic sensitivity analysis showed that prevention resulted in cost savings in 99.99% of the simulations. The threshold cost of prevention was $821.53 per day per person, whereas the cost of prevention was estimated to be $54.66 per day per person. Conclusion: This study suggests that it is more cost effective to pay for prevention of HAPUs compared with standard care. Continuous preventive care of HAPUs in acutely ill patients could potentially reduce incidence and prevalence, as well as lead to lower expenditures.
Mechanical property design of molecular solids Mishra, Manish Kumar; Ramamurty, Upadrasta; Desiraju, Gautam R.
Current opinion in solid state & materials science,
December 2016, 2016-12-00, Volume:
20, Issue:
6
Journal Article
Peer reviewed
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•Crystal engineering principles applied to design and modulation of mechanical properties of molecular solids.•Elastic crystals obtained by designing of isotropic weak interactions ...and interlocked crystal packing.•Solid-solution strengthening effectively utilized to engineer the hardness of organic solids.•Cocrystallization approach used to alter the mechanical properties of active pharmaceutical ingredients.•Nanoindentation technique establishes structure-mechanical properties correlations in molecular solids.
The current emphasis of crystal engineering, which has evolved over the past three decades through crystal packing analysis and identification of crystal design strategies, has shifted from structure to properties, i.e., design of molecular solids with targeted combination of properties. Amongst the panoply of chemical, physical, and biological properties that these materials exhibit, a comprehensive understanding of the mechanical properties is perhaps the most challenging as it involves connecting molecular level structural features to macroscopic mechanical behavior. However, the adoption of the nanoindentation technique, with which it is possible to measure—both quantitatively and accurately—the mechanical response of even small single crystals, in crystal engineering, has paved the way for substantial progress in the recent past. In this review, we summarize some recent results with an emphasis as to how one can design and control properties of molecular solids such as elastic modulus and hardness. This review closes with an enumeration of the key challenges that lie ahead. Such studies show a big scope for studying mechanical properties of organic crystals as a function of crystal structure, and in turn to understand their structure-property relationship for designing future smart materials. This emerging research field has prospects and a potential to play an important role in the future development of crystal engineering.
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