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1.
Dalton Trans ; 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39253790

RESUMEN

In this study, we report the efficient removal of organic dyes from aqueous solutions using a newly synthesized pyrene-appended Zn(II)-based metal-organic framework (MOF), ZnSiF6Pyrene MOF, with the chemical formula C52H32F6N4SiZn·4(CHCl3). The MOF was synthesized through a facile method at room temperature using a dipyridylpyrene ligand and ZnSiF6 metal source, resulting in a highly crystalline structure with pyrene functional groups forming the framework. The synthesized MOF was characterized using various analytical techniques, including Fourier-transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD) analysis, and scanning electron microscopy (SEM). Thermal stability was assessed using thermogravimetric analysis (TGA), while the surface area of the MOF was determined using a Brunauer-Emmett-Teller (BET) surface analyzer. Furthermore, the single-crystal X-ray diffraction (SCXRD) structure was studied to authenticate its solid-state structure. The as-synthesized MOF exhibited remarkable adsorption capacity towards various organic dyes, including Congo red (CR), rhodamine B (RhB), and methyl violet (MV), due to its ample surface area and strong π-π interactions between the pyrene moieties and dye molecules, as demonstrated by experimental and in silico docking studies. The photocatalytic degradation of MV dye was also investigated. Detailed trapping tests indicate that hydroxyl (˙OH) and superoxide (O2˙-) radicals are likely the primary active species responsible for the photodegradation of the dye under study. Furthermore, the photocatalytic property of the MOF was investigated under visible light irradiation, demonstrating excellent ability to generate singlet oxygen. This study highlights the potential of pyrene-appended Zn(II)-based MOFs as promising materials for environmental remediation applications.

2.
Dalton Trans ; 2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-39189403

RESUMEN

Design and development of novel, low-cost and efficient electrocatalysts for oxygen evolution reaction (OER) in alkaline media is crucial for lowering the reaction overpotential and thus decreasing the energy input during the water electrolysis process. Herein, we present the synthesis of new 14-membered bis-thiosemicarbazide and bis-isothiosemicarbazide macrocycles and their nickel(II) complexes characterized by spectroscopic techniques (1H and 13C NMR, IR, UV-vis), electrospray ionization mass spectrometry, single crystal X-ray diffraction, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) and cyclic voltammetry. Finally, the activity of nickel(II) complexes towards OER is reported. NiIILSEt delivered a current density of 10 mA cm-2 at the lowest overpotential of 350 mV with the lowest Tafel slope of 93 mV dec-1. The high performance of NiIILSEt might be attributed to its high surface area and thus abundant active sites with the observed low charge-transfer resistance enabling the effective current flow through the electrocatalyst. Square-planar coordination geometry and increment in Ni oxidation state are believed to favor its OER performance. Beside high activity towards OER, NiIILSEt demonstrated excellent long-term stability with continuous operation, advocating its possible application in commercial systems.

3.
PLoS One ; 19(8): e0307895, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39159238

RESUMEN

BACKGROUND: Construction workers are a population that is at risk for mental illnesses such as depression, anxiety, and even suicide due to the high stress and physical demands of their work. This study aimed to determine the prevalence and risk factors for depression, anxiety, and stress among Bangladeshi construction workers. METHODS: From February 2022 to June 2022, community-based cross-sectional research was conducted among construction workers. Survey data was gathered using interviewer administered questionnaires with 502 participants from the construction sites. Data were collected based on the information related to socio-demographics, lifestyle, occupation, health hazards, and mental health (i.e., depression, anxiety, and stress). The results were interpreted using the chi-square test and logistic regression utilizing SPSS statistical software. RESULTS: The study revealed the prevalence rates of depression, anxiety, and stress among construction workers to be 17.9%, 30.3%, and 12%, respectively. Key findings indicate that construction workers who maintained a healthy sleep duration were 64% less likely to be depressed compared to those with poor sleep (AOR = 0.36; 95% CI: 0.21-0.61, p<0.001). Workers who did not experience breathing issues upon starting construction work had a 45% lower likelihood of experiencing depression (AOR = 0.55; 95% CI: 0.32-0.97, p = 0.037) and an 82% lower likelihood of experiencing anxiety (AOR = 0.18; 95% CI: 0.11-0.30, p<0.001). Bricklayer construction workers were 72% less likely to experience stress (AOR = 0.28; 95% CI: 0.08-0.95, p = 0.041), and workers without breathing issues after starting construction work were 66% less likely to experience stress (AOR = 0.34; 95% CI: 0.17-0.66, p = 0.001). CONCLUSIONS: The study found that depression, anxiety, and stress are prevalent among construction workers in Bangladesh, with breathing issues as a significant risk factor. Thus, there is a need for effective measures to reduce these problems and provide a safe working environment for construction workers to ensure their productivity and the country's overall growth.


Asunto(s)
Ansiedad , Depresión , Humanos , Bangladesh/epidemiología , Adulto , Masculino , Estudios Transversales , Factores de Riesgo , Depresión/epidemiología , Prevalencia , Ansiedad/epidemiología , Femenino , Persona de Mediana Edad , Industria de la Construcción , Adulto Joven , Encuestas y Cuestionarios , Estrés Psicológico/epidemiología , Estrés Laboral/epidemiología
4.
Chemosphere ; 364: 143001, 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39121961

RESUMEN

Three novel coordination polymers (CPs), namely [Cu(µ-1κO,2κN-L)2]n (1), [Zn (µ-1κO,2κN-L)2(H2O)2]n (2) and [Cd (µ-1κOO',2κN-L)2]n (3) [where HL = 4-(pyrimidin-5-ylcarbamoyl)benzoic acid], were synthesized and characterized by elemental analysis, ATR-IR, TGA, XPS and single-crystal X-ray diffraction. Despite having the same organic ligand, the various metal cations had an impact in the subsequent frameworks. Hirshfeld surface analysis was performed to investigate the intermolecular interactions and to examine the stability of the crystal structures of the three polymers. Their catalytic performances were screened for the peroxidative oxidation of Volatile Organic Compounds (VOCs), with toluene and p-xylene selected as model substrates. Tert-butyl hydroperoxide (t-BuOOH or TBHP) (aq. 70 %) was employed as the oxidant. The catalytic oxidation of toluene yielded benzyl alcohol, benzaldehyde and benzoic acid. The copper CP 1 exhibited the highest total yield for toluene oxidation, reaching approximately 36% in an aqueous medium. For p-xylene oxidation, tolualdehyde, methylbenzyl alcohol, and toluic acid were produced as the primary products, accompanied by minor ones. The experiments were conducted under diverse conditions, manipulating key parameters such as the choice of solvent (water or acetonitrile), type of oxidant (t-BuOOH or H2O2), the concentration of the oxidant and reaction temperature. In the presence of catalyst 1, a maximum total yield of ca. 80% was achieved for p-xylene oxidation.

5.
BMC Nurs ; 23(1): 190, 2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38515143

RESUMEN

BACKGROUND: Globally, hepatitis B infection (HBI) poses a substantial public health concern and healthcare workers, including nursing students, are at a higher risk of contracting this disease. Thus, the study aimed to assess how knowledge, attitudes, and sociodemographic factors are associated with HBI prevention among a sample of Bangladeshi nursing students. METHODS: A cross-sectional survey was performed among 737 nursing students from the nursing institutes of Khulna and Barishal divisions in Bangladesh from January to April 2023. The data were collected by providing questionnaires (structured questionnaire) in the classroom, following a stratified random sampling process. A model of multinomial logistic regression was used to evaluate the factors linked to HBI prevention practices. RESULT: The mean (SD) scores were 11.42 (± 2.88) for knowledge, 4.33 (± 1.91) for attitude and 4.27 (± 2.056) for practice respectively. Participants' low knowledge (adjusted odds ratio, aOR = 2.562, 95% CI: 1.29-5.07) and poor attitude (aOR = 5.730, 95% CI: 3.19-10.28) regarding HBI were significantly associated with higher likelihood of poor practice towards HBI prevention. Moreover, being 2nd year of nursing students (aOR = 2.147, 95% CI: 1.19-3.86), being aged 19-20 years (aOR = 3.038, 95% CI: 1.30-7.09), being married (aOR = 0.320, 95%CI: 0.13-0.82) and having a family history of HBI (aOR = 0.134, 95%CI: 0.05-0.36) were significantly associated with poor practices of HBI prevention among study participants. CONCLUSION: The knowledge, attitude and practice scores of the nursing students on HBI prevention were suboptimal. We advocate for implementing regular HBI prevention education and policies, free or subsidized services, skill development, proper HBI prevention enforcement and strict professional ethics within nursing colleges. Such efforts should predominantly focus on second-year, aged 19-20 and unmarried nursing students.

6.
Dalton Trans ; 53(11): 5001-5009, 2024 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-38059528

RESUMEN

Oxygen evolution reaction (OER) electrocatalysts are frequently made from noble metal-based oxides like ruthenium/iridium oxides. However, because of their scarcity and high price, researchers are now focusing on creating innovative OER catalysts based on affordable transition metals that have improved electrical conductivity and accessibility to active sites. Metal-organic frameworks (MOFs), a unique class of inorganic materials with excellent physical and chemical properties, have witnessed significant progress in promising green energy systems. In this work, a novel mixed-ligand metal-organic framework [Co(µ-1κN,2κN'-BDP)(µ3-1κoo',2κo''2κo'''-BTC)]n·nH2O (BDP = boron-dipyrromethene or BODIPY; BTC = benzene tricarboxylate) denoted as CoBDPMOF has been synthesized, and its composites with different carbon materials have been designed. Compared to the pristine MOF, the composites showed enhanced electrocatalytic activity toward the oxygen evolution reaction (OER) in alkaline media. In addition, the CoBDPMOF with activated carbon showed the highest OER performance with a low Tafel slope (82 mV dec-1) and the highest j600 (59.8 mA cm-2), outperforming noble metal IrO2, the OER benchmark electrocatalyst. This study presents new insights into the design and application of CoBDPMOF-based materials for energy conversion and suggests promising avenues for further research and development in electrocatalysis.

7.
Molecules ; 28(3)2023 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-36770613

RESUMEN

In this work, two new 1D Cd(II) coordination polymers (CPs), [Cd(L1)(NMF)2]n (1) and [Cd(L2)(DMF)(H2O)2]n·n(H2O) (2), have been synthesized, characterized and employed as catalysts for the microwave-assisted solvent-free Strecker-type cyanation of different acetals. Solvothermal reaction between the pro-ligand, 5-{(pyren-1-ylmethyl)amino}isophthalic acid (H2L1) or 5-{(anthracen-9-ylmethyl)amino}isophthalic acid (H2L2), and Cd(NO3)2.6H2O in the presence of NMF or DMF:THF solvent, produces the coordination polymer 1 or 2, respectively. These frameworks were characterized by single-crystal and powder X-ray diffraction analyses, ATR-FTIR, elemental and thermogravimetry analysis. Their structural analysis revealed that both CPs show one-dimensional structures, but CP 1 has a 1D double chain type structure whereas CP 2 is a simple one-dimensional network. In CP 1, the dinuclear {Cd2(COO)4} unit acts as a secondary building unit (SBU) and the assembly of dinuclear SBUs with deprotonated ligand (L12-) led to the formation of a 1D double chain framework. In contrast, no SBU was observed in CP 2. To test the catalytic effectiveness of these 1D compounds, the solvent-free Strecker-type cyanation reactions of different acetals in presence of trimethylsilyl cyanide (TMSCN) was studied with CPs 1 and 2 as heterogenous catalysts. CP 1 displays a higher activity (yield 95%) compared to CP 2 (yield 84%) after the same reaction time. This is accounted for by the strong hydrogen bonding packing network in CP 2 that hampers the accessibility of the metal centers, and the presence of the dinuclear Cd(II) SBU in CP 1 which can promote the catalytic process in comparison with the mononuclear Cd(II) center in CP 2. Moreover, the recyclability and heterogeneity of both CPs were tested, demonstrating that they can be recyclable for at least for four cycles without losing their structural integrity and catalytic activity.

8.
Molecules ; 27(21)2022 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-36364154

RESUMEN

The new 3D coordination polymer (CP) [Mn(L)(HCOO)]n (Mn-CP) [L = 4-(pyridin-4-ylcarbamoyl)benzoate] was synthesised via a hydrothermal reaction using the pyridyl amide functionalized benzoic acid HL. It was characterized by elemental, FT-IR spectroscopy, single-crystal and powder X-ray diffraction (PXRD) analyses. Its structural features were disclosed by single-crystal X-ray diffraction analysis, which revealed a 3D structure with the monoclinic space group P21/c. Its performance as an electrocatalyst for oxygen reduction (ORR), oxygen evolution (OER), and hydrogen evolution (HER) reactions was tested in both acidic (0.5 M H2SO4) and alkaline (0.1 M KOH) media. A distinct reduction peak was observed at 0.53 V vs. RHE in 0.1 M KOH, which corresponds to the oxygen reduction, thus clearly demonstrating the material's activity for the ORR. Tafel analysis revealed a Tafel slope of 101 mV dec-1 with mixed kinetics of 2e- and 4e- pathways indicated by the Koutecky-Levich analysis. Conversely, the ORR peak was not present in 0.5 M H2SO4 indicating no activity of Mn-CP for this reaction in acidic media. In addition, Mn-CP demonstrated a noteworthy activity toward OER and HER in acidic media, in contrast to what was observed in 0.1 M KOH.


Asunto(s)
Amidas , Polímeros , Espectroscopía Infrarroja por Transformada de Fourier , Oxígeno , Hidrógeno
9.
J Inorg Biochem ; 220: 111466, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33933927

RESUMEN

In recent years, fluorescent sensors have emerged as attractive imaging probes due to their distinct responses toward bio-relevant metal ions. However, the bioimaging application main barrier is the 'turn-off' response toward paramagnetic metal ions such as Cu2+ under physiological conditions. Herein, we report a new sensor (2-methyl(4-bromo-N-ethylpiperazinyl-1,8-naphthalimido)-4-(1H-phenanthro[9,10-d]imidazole-2-yl) phenol)NPP with multifunctional (Naphthalimide, Piperazine, Phenanthroimidazole) units for fluorescent and colourimetric detection of Cu2+ in an aqueous medium. Both absorption and fluorescence spectral titration strategies were used to monitor the Cu2+-sensing property of NPP. The NPP displays a weak emission at ca. 455 nm, which remarkably enhances (⁓3.2-fold) upon selective binding of Cu2+ over a range of metal ions, including other paramagnetic metal ions (Mn2+, Fe3+, Co2+). The stoichiometry, binding constant (Ka) and the LOD (limit of detection) of NPP toward Cu2+ ions were found to be 1:1, 5.0 (± 0.2) × 104 M-1 and 6.5 (± 0.4) × 10-7 M, respectively. We have also used NPP as a fluorescent probe to detect Cu2+ in live (human cervical HeLa) cancer cells. The emission intensity of NPP was almost recovered in HeLa cells by incubating 'in situ' the derived Cu2+ complex (NPP-Cu2+) in the presence of a benchmark chelating agent such as EDTA (ethylenediaminetetraacetate). The fluorescent emission of NPP was reverted significantly in each cycle upon sequencial addition of Cu2+ and EDTA to the NPP solution. Overall, NPP is a novel, simple, economic and portable sensor that can detect Cu2+ in biological and environmental scenarios.


Asunto(s)
Cobre/análisis , Colorantes Fluorescentes/química , Imidazoles/química , Naftalimidas/química , Fenantrenos/química , Colorimetría/métodos , Colorantes Fluorescentes/síntesis química , Células HeLa , Humanos , Imidazoles/síntesis química , Límite de Detección , Microscopía Fluorescente , Naftalimidas/síntesis química , Fenantrenos/síntesis química , Espectrometría de Fluorescencia
10.
Molecules ; 26(4)2021 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-33669746

RESUMEN

The new coordination polymers (CPs) [Zn(µ-1κO1:1κO2-L)(H2O)2]n·n(H2O) (1) and [Cd(µ4-1κO1O2:2κN:3,4κO3-L)(H2O)]n·n(H2O) (2) are reported, being prepared by the solvothermal reactions of 5-{(pyren-4-ylmethyl)amino}isophthalic acid (H2L) with Zn(NO3)2.6H2O or Cd(NO3)2.4H2O, respectively. They were synthesized in a basic ethanolic medium or a DMF:H2O mixture, respectively. These compounds were characterized by single-crystal X-ray diffraction, FTIR spectroscopy, thermogravimetric and elemental analysis. The single-crystal X-ray diffraction analysis revealed that compound 1 is a one dimensional linear coordination polymer, whereas 2 presents a two dimensional network. In both compounds, the coordinating ligand (L2-) is twisted due to the rotation of the pyrene ring around the CH2-NH bond. In compound 1, the Zn(II) metal ion has a tetrahedral geometry, whereas, in 2, the dinuclear [Cd2(COO)2] moiety acts as a secondary building unit and the Cd(II) ion possesses a distorted octahedral geometry. Recently, several CPs have been explored for the cyanosilylation reaction under conventional conditions, but microwave-assisted cyanosilylation of aldehydes catalyzed by CPs has not yet been well studied. Thus, we have tested the solvent-free microwave-assisted cyanosilylation reactions of different aldehydes, with trimethylsilyl cyanide, using our synthesized compounds, which behave as highly active heterogeneous catalysts. The coordination polymer 1 is more effective than 2, conceivably due to the higher Lewis acidity of the Zn(II) than the Cd(II) center and to a higher accessibility of the metal centers in the former framework. We have also checked the heterogeneity and recyclability of these coordination polymers, showing that they remain active at least after four recyclings.


Asunto(s)
Aldehídos/química , Cianuros/química , Microondas , Polímeros/química , Pirenos/química , Compuestos de Trimetilsililo/química , Catálisis , Enlace de Hidrógeno , Ligandos , Modelos Moleculares , Conformación Molecular , Polímeros/síntesis química , Solventes , Termogravimetría
11.
Dalton Trans ; 50(10): 3701-3716, 2021 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-33634805

RESUMEN

Two new benzimidazole Schiff base copper(ii) compounds [Cu(5-CH2PPh3-2-salmethylben)(NO3)(H2O)][BF4]·2/3(H2O)·1/3(MeOH) (1) and [Cu(5-CH2NEt3-2-salmethylben)(Cl)][BF4] (2) were synthesised by mixing 2-(1-methyl-1H-benzo[d]imidazol-2-yl)aniline, (3-formyl-4-hydroxybenzyl)triphenylphosphonium chloride or N,N-diethyl-N-(3-formyl-4-hydroxybenzyl)ethanaminium chloride and Cu(NO3)2·3H2O or CuCl2·2H2O in the presence of tetrafluoroborate in a binary mixture of MeOH : H2O under refluxing conditions. The structures of the compounds were established by elemental analysis, FT-IR, ESI-MS analytical techniques and, for 1, by single-crystal X-ray diffraction analysis. Absorption and fluorescence spectroscopic methods were performed to evaluate the calf thymus DNA interactions with the compounds. The calculated binding constants (Kb) of 3.14 × 105 M-1 for 1 and 3.20 × 105 M-1 for 2 were established. The intercalative DNA binding mode was also verified by molecular docking studies. Both compounds demonstrated a notable in vitro cytotoxic effect against human A-549 (lung carcinoma), MCF-7 (breast cancer) and HeLa (cervical cancer) cancer cell lines. A substantial repressive effect on the proliferation of MCF-7 cells (breast cancer cells) was observed for compound 1. The mechanism of action for the effective antiproliferative activity of 1 has additionally been confirmed by means of various biological studies such as morphological assessment through AO/EB, detection of apoptotic induction via Hoechst/PI dual staining, flow cytometry for detection of cell cycle arrest, quantitative analysis of apoptotic cells, DNA degradation, generation of reactive oxygen species (ROS) and by apoptotic induction through mitochondrial staining.


Asunto(s)
Antineoplásicos/farmacología , Bencimidazoles/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Complejos de Coordinación/farmacología , Cobre/farmacología , ADN/efectos de los fármacos , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Bencimidazoles/química , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Bovinos , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Complejos de Coordinación/síntesis química , Complejos de Coordinación/química , Cobre/química , Cristalografía por Rayos X , ADN/química , ADN/metabolismo , Teoría Funcional de la Densidad , Ensayos de Selección de Medicamentos Antitumorales , Estrógenos/metabolismo , Femenino , Humanos , Simulación del Acoplamiento Molecular , Bases de Schiff/química , Bases de Schiff/farmacología
12.
Inorg Chem ; 59(22): 16301-16318, 2020 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-33100004

RESUMEN

The new 2D coordination polymers (CPs) [M(L)2(H2O)2]n [M = CoII (1) and NiII (2); L = 4-(pyridin-3-ylcarbamoyl)benzoate] were synthesized from pyridyl amide-functionalized benzoic acid (HL). They were characterized by elemental, Fourier transform infrared, thermogravimetric, powder X-ray diffraction (PXRD), and single-crystal X-ray diffraction (XRD) structural analyses. Single-crystal XRD analysis revealed the presence of a 2D polymeric architecture, and topological analyses disclose a 2,4-connected binodal net. A thermochromic effect leads to the production of two new CPs, 1' and 2', by heating at ca. 220 °C, accompanied by a color change from orange to purple in the case of 1 and from blue to green in the case of 2. The transformation of 1 to 1' takes place through an intermediate (1a) with a different twist of the L- ligand, leading to the formation of a 1D polymeric architecture, as proven by single-crystal XRD analysis. The addition of water or keeping 1' or 2' in air for several days leads to regeneration of 1 or 2, respectively. The thermochromic-triggered structural transformations of 1 and 2 were further substantiated by PXRD and UV-vis ground-state diffuse-reflectance absorption studies. The supercapacitance ability of the CPs 1 and 2 and a Ni-Co composite (made from mixing the CPs 1 and 2) was investigated by electroanalytical techniques, such as cyclic voltammetry and electrochemical impedance spectroscopy. The CP 2 exhibits the highest specific capacity of 273.8 C g-1 at an applied current density of 1.5 A g-1. These newly developed CPs further act as electrocatalysts for the water-splitting reaction.

13.
Dalton Trans ; 49(37): 12970-12984, 2020 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-32936184

RESUMEN

New CPs [Zn(µ-1κOO':2κN-L)(H2O)(BDC)0.5]n·n(DMF) (1), [Cd(µ-1κO:2κN-L)2(H2O)2]n (2), and [Pb(µ-1κOO':2κO'-L)(µ-1κO:2κO':3κN-L)]n (3) [L = 4-(pyridin-3-ylcarbamoyl)benzoate; BDC = benzene-1,4-dicarboxylate] were synthesized and characterized by elemental, FT-IR, powder, and single-crystal X-ray diffraction analyses. Single crystal X-ray diffraction analysis discloses 1D polymeric architectures for 1 and 2 and a 2D one for 3. The topological analysis exemplifies a 2,2,3-connected 3-nodal net with the point symbol {82·12}2{8}3 for 1, a 2,4-connected bimodal net for 2, and a 3,4,7-connected trinodal net for 3. CP 1 shows a selective removal of the Congo Red (CR) dye amongst various dyes. It can be recycled and reused without any significant loss of its dye removal efficiency. An insight into the selective removal of the Congo dye is provided by in silico studies, being accounted for by anion-π, cation-π, and π-π stacking interactions, involving the Zn(ii) ion, phenyl rings, and Ocarboxylate of L, and the phenyl rings, naphthalene rings, and Osulfonate of CR.

14.
Molecules ; 25(11)2020 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-32517273

RESUMEN

The mononuclear zinc(II) complex cis-[ZnL2(H2O)2] (1; L = 4-(pyridin-3-ylcarbamoyl)benzoate) was synthesized and characterized. By soaking crystals of 1 in a mixture of DMF-H2O solution containing a slight excess of Cu(NO3)2 × 3H2O a transmetalation reaction occurred affording the related copper(II) complex trans-[CuL2(H2O)2] (2). The structures of the compounds were authenticated by single crystal X-ray diffraction revealing, apart from a change in the isomerism, an alteration in the relative orientation of the chelating carboxylate groups and of the pyridine moieties. H-bond interactions stabilize both geometries and expand them into two-dimensional (2D) networks. The transmetalation was confirmed by SEM-EDS analysis. Moreover, the thermodynamic feasibility of the transmetalation is demonstrated by density-functional theory (DFT) studies. The catalytic activities of 1 and 2 for the oxidation of styrene and for the nitroaldol (Henry) C-C coupling reaction were investigated. The copper(II) compound 2 acts as heterogeneous catalyst for the microwave-assisted oxidation of styrene with aqueous hydrogen peroxide, yielding selectively (>99%) benzaldehyde up to 66% of conversion and with a turnover frequency (TOF) of 132 h-1. The zinc(II) complex 1 is the most active catalyst (up to 87% yield) towards the nitroaldol (Henry) coupling reaction between benzaldehyde and nitro-methane or -ethane to afford the corresponding ß-nitro alcohols. The reaction of benzaldehyde with nitroethane in the presence of 1 produced 2-nitro-1-phenylpropanol in the syn and the anti diastereoisomeric forms, with a considerable higher selectivity towards the former (66:34).


Asunto(s)
Amidas/química , Quelantes/química , Cobre/química , Compuestos Heterocíclicos con 3 Anillos/química , Nitrocompuestos/química , Estireno/química , Zinc/química , Catálisis , Modelos Moleculares , Oxidación-Reducción
15.
Metabolomics ; 16(3): 38, 2020 03 11.
Artículo en Inglés | MEDLINE | ID: mdl-32162079

RESUMEN

INTRODUCTION: Oral cancer is a sixth commonly occurring cancer globally. The use of tobacco and alcohol consumption are being considered as the major risk factors for oral cancer. The metabolic profiling of tissue specimens for developing carcinogenic perturbations will allow better prognosis. OBJECTIVES: To profile and generate precise 1H HRMAS NMR spectral and quantitative statistical models of oral squamous cell carcinoma (OSCC) in tissue specimens including tumor, bed, margin and facial muscles. To apply the model in blinded prediction of malignancy among oral and neck tissues in an unknown set of patients suffering from OSCC along with neck invasion. METHODS: Statistical models of 1H HRMAS NMR spectral data on 180 tissues comprising tumor, margin and bed from 43 OSCC patients were performed. The combined metabolites, lipids spectral intensity and concentration-based malignancy prediction models were proposed. Further, 64 tissue specimens from twelve patients, including neck invasions, were tested for malignancy in a blinded manner. RESULTS: Forty-eight metabolites including lipids have been quantified in tumor and adjacent tissues. All metabolites other than lipids were found to be upregulated in malignant tissues except for ambiguous glucose. All of three prediction models have successfully identified malignancy status among blinded set of 64 tissues from 12 OSCC patients with an accuracy of above 90%. CONCLUSION: The efficiency of the models in malignancy prediction based on tumor induced metabolic perturbations supported by histopathological validation may revolutionize the OSCC assessment. Further, the results may enable machine learning to trace tumor induced altered metabolic pathways for better pattern recognition. Thus, it complements the newly developed REIMS-MS iKnife real time precession during surgery.


Asunto(s)
Carcinoma de Células Escamosas/metabolismo , Metabolómica , Neoplasias de la Boca/metabolismo , Adulto , Carcinoma de Células Escamosas/patología , Humanos , Modelos Biológicos , Neoplasias de la Boca/patología , Espectroscopía de Protones por Resonancia Magnética
16.
Front Chem ; 7: 699, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31709229

RESUMEN

A pyridine-based amide functionalized tetracarboxylic acid, 5,5'-(pyridine-2, 6-dicarbonyl)bis(azanediyl)}diisophthalic acid (H4L), was synthesized and its coordination chemistry toward zinc(II) and cadmium(II) ions was studied. The reactions of H4L with Zn(NO3)2.6H2O and Cd(NO3)2.4H2O led to its full or partial deprotonation, respectively, and the formation of the 2D coordination polymers [Zn2(L)(H2O)4]n.4n(H2O) (1) and [Cd3(HL)2(DMF)4]n.4n(DMF) (2) (DMF = N,N'-dimethylformamide), respectively. They were characterized by elemental analysis, FT-IR, photoluminescence, thermogravimetry, and single-crystal and powder X-ray diffraction. In 1, the L4- ligand is planar with every carboxylate anion binding a Zn(II) cation and giving rise to a 2D grid with the metals with tetrahedral environments. In 2, the combination of bridging HL3- and dimethylformamide to form trinuclear Cd(II) clusters engenders secondary building block units and generates a layer-type 2D network with the metals with octahedral and pentagonal bipyramid coordination geometries. The topological analyses of 1 and 2 reveal 2,4-connected and 3,6-connected binodal nets, respectively. On account of the presence of Lewis acid (Zn or Cd centers) as well as basic (uncoordinated pyridine and amide groups) sites, 1 and (to a much lower extent) 2 effectively catalyze the one-pot cascade deacetalization-Knoevenagel condensation reactions under quite mild conditions. They act as heterogeneous catalysts, being easy to recover and recycle without losing activity.

17.
BMC Health Serv Res ; 19(1): 424, 2019 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-31242900

RESUMEN

BACKGROUND: How the informal providers deliver health services are not well understood in Bangladesh. However, their practices are often considered inappropriate and unsafe. This study attempted to fill-in this knowledge gap by exploring their perceptions about diagnosis and appropriate treatment, as well as identifying existing barriers to provide appropriate treatment. METHODS: This exploratory study was conducted in two peri-urban areas of metropolitan Dhaka. Study participants were selected purposively, and an interview guideline was used to collect in-depth data from thirteen providers. Content analysis was applied through data immersion and themes identification, including coding and sub-coding, as well as data display matrix creation to draw conclusion. RESULTS: The providers relied mainly on the history and presenting symptoms for diagnosis. Information and guidelines provided by the pharmaceutical representatives were important aids in their diagnosis and treatment decision making. Lack of training, diagnostic tools and medicine, along with consumer demands for certain medicine i.e. antibiotics, were cited as barriers to deliver appropriate care. Effective and supportive supervision, training, patient education, and availability of diagnostics and guidelines in Bangla were considered necessary in overcoming these barriers. CONCLUSION: Informal providers lack the knowledge and skills for delivering appropriate treatment and care. As they provide health services for substantial proportion of the population, it's crucial that policy makers become cognizant of the fact and take measures to remedy them. This is even more urgent if government's goal to reach universal health coverage by 2030 is to be achieved.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Personal de Salud/psicología , Personal de Salud/normas , Adulto , Bangladesh , Femenino , Personal de Salud/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Investigación Cualitativa , Población Suburbana
18.
J Therm Biol ; 78: 329-342, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30509655

RESUMEN

Attaining a precise necrosis of tumor sparing normal tissue during carcinomas thermo-therapy via nominally invasive scheme like irradiation of laser is a recent challenge. In this study, a combined diffusion and convective energy equations were solved using COMSOL Multiphysics to predict the tissue thermal profile during laser assisted thermo-therapy with different tissue vascular networks. A comparative analysis between intratumoral and intravenous loading scheme of silica-gold nanoshells (AuNs) was also performed. AuNs cluster position and alignment was altered to achieve precise ablation of a large tumor with minimum damage to healthy tissue and improvement in necrosis in the vicinity of large blood vessels (LBV). A modified Beer-Lambert law and Arrhenius equation was applied to model laser heat propagation and to compute thermal damage respectively. Simulation results suggests the dominance of targeted nanostructure injection in cluster form over intravenous scheme in terms of precise control over spreading of necrotic zone due to selective laser dose delivery into the tumor. An effective tumor ablation, sparing normal tissue is best revealed for Type-A intratumoral scheme comparing Type-B and C as the reallocation of cluster position can help to achieve an irregular shaped necrotic zone. In addition a comparative analysis between dual-phase-lag (DPL) and classical Fourier approach within a tumor-blood inhomogeneous inner structure was made to access the effect of relaxation time onto biological thermal response. Numerical results show a difference in temperature profile between these two approaches during non-equilibrium condition i.e at the prior phases of laser heating and cooling whereas the results overlaps at higher instants. Since the DPL based bioheat conduction model can predict the inherent wave nature of the thermal front which is propagating at a finite speed. This study may improve the real clinical invasive schemes applied to ablate malignant tumor during hyperthermia treatment.


Asunto(s)
Vasos Sanguíneos/patología , Hipertermia Inducida/métodos , Nanopartículas del Metal/uso terapéutico , Modelos Teóricos , Neoplasias/terapia , Fototerapia/métodos , Oro/química , Humanos , Nanopartículas del Metal/química , Necrosis , Dióxido de Silicio/química
19.
Metabolomics ; 14(9): 119, 2018 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-30830375

RESUMEN

INTRODUCTION: Breast cancer is the most frequent diagnosed cancer among women with a mortality rate of 15% of all cancer related deaths in women. Breast cancer is heterogeneous in nature and produces plethora of metabolites allowing its early detection using molecular diagnostic techniques like magnetic resonance spectroscopy. OBJECTIVES: To evaluate the variation in metabolic profile of breast cancer focusing on lipids as triglycerides (TG) and free fatty acids (FFA) that may alter in malignant breast tissues and lymph nodes from adjacent benign breast tissues by HRMAS 1H NMR spectroscopy. METHODS: The 1H NMR spectra recorded on 173 tissue specimens comprising of breast tumor tissues, adjacent tissues, few lymph nodes and overlying skin tissues obtained from 67 patients suffering from breast cancer. Multivariate statistical analysis was employed to identify metabolites acting as major confounders for differentiation of malignancy. RESULT: Reduction in lipid content were observed in malignant breast tissues along with a higher fraction of FFA. Four small molecule metabolites e.g., choline containing compounds (Chocc), taurine, glycine, and glutamate were also identified as major confounders. The test set for prediction provided sensitivity and specificity of more than 90% excluding the lymph nodes and skin tissues. CONCLUSION: Fatty acids composition in breast cancer using in vivo magnetic resonance spectroscopy (MRS) is gaining its importance in clinical settings (Coum et al. in Magn Reson Mater Phys Biol Med 29:1-4, 2016). The present study may help in future for precise evaluation of lipid classification including small molecules as a source of early diagnosis of invasive ductal carcinoma by employing in vivo magnetic resonance spectroscopic methods.


Asunto(s)
Neoplasias de la Mama/metabolismo , Lípidos/análisis , Metabolómica , Neoplasias de la Mama/diagnóstico , Colina/análisis , Colina/metabolismo , Femenino , Ácido Glutámico/análisis , Ácido Glutámico/metabolismo , Glicina/análisis , Glicina/metabolismo , Humanos , Persona de Mediana Edad , Análisis Multivariante , Espectroscopía de Protones por Resonancia Magnética , Taurina/análisis , Taurina/metabolismo
20.
J Inorg Biochem ; 174: 25-36, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28599129

RESUMEN

Synthesis, inter-conversions and biological study of the dichloro bridged dicopper(II) compound [CuLCl]2 (1) and its two mononuclear derivatives [CuLCl(H2O)]·H2O (2) and [CuLCl(py)] (3) (HL=2-(2-pyridylmethyleneamino)benzenesulfonic acid) are described. The dimeric compound 1 collapses into monomers 2 and 3 in the presence of coordinating solvents, water and pyridine, respectively, and 1 is regenerated upon simple stirring of 2 or 3 in methanol. The reactions of 1 with neutral (present study) and charged (earlier studies) ligands result in monomeric and multimeric compounds, respectively, attesting that it is a versatile dicopper(II) precursor. The anticancer activity of these copper complexes (1-3) was screened against lung (A-549) and breast (MDA-MB-231) human cancer cell lines. The IC50 (half maximal inhibitory concentration) value for one (3) of the compounds suggests preferential cytotoxicity against breast cancer MDA-MB-231 cell line. Furthermore, the IC50 value obtained for complex 3 is found to be almost two-fold times cytotoxic than the standard drug cisplatin. In addition, the underlying possible mechanism of its apoptosis-inducing efficacy in MDA-MB-231 cells has been rationalized by using flow cytometry (FACS) and Hoechst 33342/propidium iodide (PI) fluorescence staining. The stimulation of apoptotic induction for complex 3 has further been affirmed by reactive oxygen species (ROS) generation and mitochondrial aggregations studies.


Asunto(s)
Apoptosis/efectos de los fármacos , Neoplasias de la Mama/metabolismo , Complejos de Coordinación , Cobre , Mitocondrias/metabolismo , Células A549 , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Complejos de Coordinación/síntesis química , Complejos de Coordinación/química , Complejos de Coordinación/farmacología , Cobre/química , Cobre/farmacología , Femenino , Humanos , Mitocondrias/patología
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