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1.
Bioinorg Chem Appl ; 2023: 1731931, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37125143

RESUMO

One of the more enticing, ecologically responsible, as well as safe and sustainable methodologies is eco-friendly nanomaterial synthesis. Vegetation materials will be used as reductants instead of toxic substances for synthesising nanoparticles. The current study used Ruellia tuberosa (RT) leaf extract digest to synthesise FeO nanomaterials, which were then characterised using XRD. Following that, microbially produced FeO molecules were mixed with a Kevlar-based polymeric matrix to study the blended consequences. To examine the interbreeding, the current experimental analyses were performed, including both static and dynamic mechanical characteristics. The addition of FeO nanofillers improved the elastic modulus, tensile strength, and storage modulus of the nanocomposite. Impact force uptake has been raised to a certain extent by the addition of nanoparticles. The findings of this research show that incorporating FeO nanofillers into Kevlar fabrics is a promising technique for increasing the mechanical characteristics of hybrid laminated composites. As per DMA evaluation, the sample without nanomaterials had a more volcanic lava response, which is a useful thing for body systems for missile use. Another critical aspect of a nanoparticles-filled nanocomposite that must be addressed is the relatively uniform scattering of padding as well as the development of interfacial adhesion in such a combination. The presence of FeO fillers in polymeric composites is confirmed by XRD analysis.

2.
Indian J Pathol Microbiol ; 65(1): 167-169, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35074987

RESUMO

Kaposiform hemangioendothelioma (KHE) is a locally aggressive vascular tumor usually seen in children. It is frequently associated with Kasabach-Merritt phenomenon. Here we report two cases of KHE: the first case being an 11-month-old boy who came with massive swelling on the face and violaceous discoloration. The second case was a 7-year-old boy who presented with respiratory distress and bleeding manifestations. CT scan chest showed a large mass involving the anterior mediastinum. Histologic examination of resected masses from both these cases showed features of KHE involving subcutaneous tissue and thymus, respectively. Although cutaneous and subcutaneous location is common, thymic involvement is unusual. It is important to distinguish KHE from infantile haemangioma, tufted angioma, spindle-cell haemangioma, verrucous malformation and Kaposi sarcoma. Histologic features, supportive immunohistochemistry and the clinical profile together are helpful to differentiate KHE from other vascular lesions.


Assuntos
Hemangioendotelioma/diagnóstico por imagem , Hemangioendotelioma/patologia , Síndrome de Kasabach-Merritt/diagnóstico por imagem , Síndrome de Kasabach-Merritt/patologia , Sarcoma de Kaposi/diagnóstico por imagem , Sarcoma de Kaposi/patologia , Neoplasias Vasculares/diagnóstico por imagem , Neoplasias Vasculares/patologia , Criança , Diagnóstico Diferencial , Técnicas Histológicas , Humanos , Imuno-Histoquímica , Lactente , Masculino , Tórax/diagnóstico por imagem , Tomografia Computadorizada por Raios X
3.
Mater Today Proc ; 56: 2213-2216, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34877264

RESUMO

Cancer victims, particularly those with lung cancer, are more susceptible and at higher danger of COVID-19 and associated consequences as a result of their compromised immune systems, which makes them particularly sensitive. Because of a variety of circumstances, cancer patients' diagnosis, treatment, and aftercare are very complicated and time-consuming during an epidemic. In such circumstances, advances in artificial intelligence (AI) and machine learning algorithms (ML) offer the capacity to boost cancer sufferer diagnosis, therapy, and care via the use of cutting technologies. For example, using clinical and imaging data combined with machine learning methods, the researchers may be able to distinguish among lung alterations induced by corona virus and those produced by immunotherapy and radiation. During this epidemic, artificial intelligence (AI) may be utilized to guarantee that the appropriate individuals are recruited in cancer clinical trials more quickly and effectively than in the past, which was done in a conventional and complicated manner. In order to better care for cancer patients and find novel and more effective therapies, It is critical that we move beyond traditional research methods and use artificial intelligence (AI) and machine learning to update our research (ML). Artificial intelligence (AI) and machine learning (ML) are being utilised to help with several aspects of the COVID-19 epidemic, such as epidemiology, molecular research and medication development, medical diagnosis and treatment, and socioeconomics. The use of artificial intelligence (AI) and machine learning (ML) in the diagnosis and treatment of COVID-19 patients is also being investigated. The combination of artificial intelligence and machine learning in COVID-19 may help to identify positive patients more quickly. In order to understand the dynamics of an epidemic that is relevant to artificial intelligence, when used in different patient groups, AI-based algorithms can quickly detect CT scans with COVID-19 linked pneumonia, as well as discriminate non-COVID connected pneumonia with high specificity and accuracy. It is possible to utilize the existing difficulties and future views presented in this study to guide an optimal implementation of AI and machine learning technologies in an epidemic.

4.
Indian J Pathol Microbiol ; 64(2): 379-381, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33851640

RESUMO

WHO classification of adrenal tumors. Only a handful of cases have been reported so far. A 30-year-old lady presented with cerebrovascular accident. CT scans of the abdomen and pelvis revealed a 3.5-cm well-defined, smooth margined, heterogeneously enhancing, mass lesion in the right adrenal gland. She had no endocrine symptoms and urinary metanephnines were normal. She underwent right adrenalectomy for incidentaloma. Histopathology of the excised mass showed features of an adrenal schwannoma. Diagnosis of adrenal schwannoma on imaging studies is difficult preoperatively and raises suspicion of other adrenal tumors. Surgical excision followed by histopathology confirms the diagnosis.


Assuntos
Neoplasias das Glândulas Suprarrenais/diagnóstico , Neoplasias das Glândulas Suprarrenais/cirurgia , Glândulas Suprarrenais/patologia , Neurilemoma/diagnóstico , Neurilemoma/patologia , Neoplasias das Glândulas Suprarrenais/patologia , Glândulas Suprarrenais/cirurgia , Adulto , Feminino , Humanos , Achados Incidentais , Neurilemoma/cirurgia , Acidente Vascular Cerebral/patologia , Tomografia Computadorizada por Raios X
5.
Indian J Med Paediatr Oncol ; 38(1): 65-66, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28469340

RESUMO

Hemangioendothelioma is a vascular tumor of endothelial nature of intermediate grade. It most commonly arises from soft tissue of upper and lower extremities. We report a rare case of epithelioid hemangioendothelioma of the urinary bladder. Histologically, it was a vascular tumor formed by smaller capillaries lined by plump epithelioid cells having eosinophilic cytoplasm. Diagnosis was confirmed by immunohistochemistry, as the tumor cells were positive for CD34 and smooth muscle actin.

6.
Artigo em Inglês | MEDLINE | ID: mdl-26189161

RESUMO

The present work reports supramolecular interaction of [6,6]-phenyl C71 butyric acid methyl ester (PC70BM) with two designed diporphyrin molecules having dithiophene (1) and carbazole (2) spacer in solvent having varying polarity. Studies on complex formation reveal relatively higher binding constant for PC70BM/2 complex in all the solvent studied. Solvent dependence of charge separation and charge recombination processes in PC70BM/diporphyrin non-covalent complexes has been well established in present work. Donor-acceptor geometry and stabilization of the singlet excited state of the diporphyrin during charge recombination are considered to be the possible reasons for this behavior.

7.
Spectrochim Acta A Mol Biomol Spectrosc ; 150: 992-1001, 2015 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-26123516

RESUMO

Photoinduced processes in phthalocyanine/functionalized gold nanoparticles (Pc/AuNps) have been investigated by spectroscopic measurements. It is observed while AuNps reduce the magnitude of binding constant for the non-covalent complexation between [6,6]-phenyl C71 butyric acid methyl ester (PC70BM) and H2-Pc by 15.8 times in comparison to PC70BM/ZnPc system in toluene, fluorescence of ZnPc is strongly quenched in presence of AuNp. Fluorescence lifetime determined by time-correlated single photon counting is also strongly reduced for ZnPc in presence of AuNp compared to H2-Pc. Symbolic enhancement in quantum yield of charge-separation associated with well-defined electrostatic interaction has been confirmed for PC70BM/ZnPc supramolecule in presence of AuNp. Transient absorption measurements establish that energy transfer mechanism is operative for both PC70BM/H2-Pc and PC70BM/ZnPc supramolecules in absence and presence of AuNp in toluene.

8.
Spectrochim Acta A Mol Biomol Spectrosc ; 135: 386-97, 2015 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-25104284

RESUMO

Efforts to improve the ease of self-assembly formation through non-covalent interaction has led to the development of zinc phthalocyanine (zinc-2,9,16,23-tetra-tert-butyl phthalocyanine, i.e., ZnPc) as a high potential photosensitizer molecule towards C60 pyrrolidine tris-acid ethyl ester (PyC60) in toluene and 1,2-dichlorobenzene (DCB). Steady state fluorescence experiment elicits efficient quenching of the fluorescence intensity of both H2- and ZnPc in presence of PyC60. The average value of binding constant for PyC60/H2-Pc and PyC60/ZnPc systems in toluene (DCB) are determined to be 9910 (13,460) and 12,710 (24,060) dm(3) mol(-1), respectively. Lifetime experiment yields ∼3 times larger magnitude of charge separated rate constant for the PyC60/ZnPc system compared to PyC60/H2-Pc in toluene. Photoinduced energy transfer between PyC60 and H2- (/ZnPc) has been evidenced with nanosecond laser photolysis method; transient absorption studies establish that energy transfer from (T)PyC60(∗) to H2- and ZnPc occurs predominantly, as confirmed by the consecutive appearance of the triplet states of PyC60.


Assuntos
Fulerenos/química , Indóis/química , Compostos Organometálicos/química , Fármacos Fotossensibilizantes/química , Absorção Fisico-Química , Isoindóis , Cinética , Modelos Moleculares , Espectroscopia de Prótons por Ressonância Magnética , Prótons , Teoria Quântica , Solventes , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Eletricidade Estática , Fatores de Tempo , Compostos de Zinco
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 134: 566-73, 2015 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-25138385

RESUMO

Present work reports the photophysical insights on supramolecular interaction of a C70 derivative, namely, [6,6]-phenyl C71 butyric acid methyl ester (PC70BM), with two designed diporphyrin molecules having dithiophene (1) and carbazole (2) spacer in toluene and benzonitrile. Both absorption spectrophotometric and steady state fluorescence investigations reveal efficient complexation of PC70BM with 1 and 2 in both toluene and benzonitrile. The magnitude of average value of binding constant, viz., Kav, for the complexes of PC70BM with 1 and 2 in toluene (benzonitrile) are estimated to be 2.185 × 10(3)dm(3)mol(-1) (3.215 × 10(3)dm(3)mol(-1)) and 10.180 × 10(3)dm(3)mol(-1) (25.405 × 10(3)dm(3)mol(-1)), respectively. Selectivity in binding for the complexation process of PC70BM with 1 and 2 is estimated to be ∼4.6 and ∼7.90 as observed in toluene and benzonitrile, respectively. The complexation between PC70BM and diporphyrin is well accounted by a theoretical model which takes into account the electronic subsystems of both acceptor and donor. Ab initio calculations in vacuo establish that size selective orientation pattern of PC70BM towards the cavity of diporphyrin dictates the magnitude of binding and electronic structure of the PC70BM/diporphyrin complexes.


Assuntos
Derivados de Benzeno/química , Ácido Butírico/química , Porfirinas/química , Fulerenos/química , Modelos Moleculares , Teoria Quântica , Solventes , Espectrometria de Fluorescência
10.
Spectrochim Acta A Mol Biomol Spectrosc ; 138: 958-63, 2015 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-25440580

RESUMO

Fulleropyrrolidine (PyC60) and a binaphthyl bridged crown ether macrocyclic receptor (1) undergoes spontaneous self-assembly phenomenon in solution to generate a new supramolecular recognition element having binding constant value of ∼5.83×10(4)dm(3)mol(-1). Lifetime measurement reveals a static quenching mechanism behind the deactivation of photoexcited state of 1 in presence of PyC60. The results obtained from this work would definitely reinforce bridged cyclic crown ether as one of the most suitable fragments for the molecular recognition of various macrocyclic receptor(s) in near future.


Assuntos
Éteres de Coroa/química , Fulerenos/química , Naftalenos/química , Cinética , Conformação Molecular , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Eletricidade Estática , Fatores de Tempo
11.
Indian J Surg Oncol ; 6(3): 271-5, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27217677

RESUMO

The tumors of dendritic/reticulum cells constitutes the rarest tumors affecting the lymphoid tissues. Among them tumors derived from fibroblastic reticular cells (FBRCs) are very rare, and those of cytokeratin (CK)-positive interstitial reticulum cells (CIRCs) origin are even more rare. These tumors can be easily misdiagnosed as tumors of other dendritic cells, myofibroblastic tumors or even metastatic poorly differentiated carcinomas. Less than twenty such cases have been reported in the literature till date. We present such a rare case of CIRC sarcoma in cervical lymph node of a 64-year-old man.

12.
Artigo em Inglês | MEDLINE | ID: mdl-24858347

RESUMO

The present article reports the role of gold nanoparticles, i.e., AuNp (having diameter ∼2-4nm), in non-covalent interaction between fullerenes (C60 and C70) and a monoporphyrin (1) in toluene. Both UV-vis and fluorescence measurements reveal considerable reduction in the average value of binding constant (Kav) for the C70-1 system (KC70-1(av)=19,300 dm3 mol(-1)) in presence of AuNp, i.e., KC70-1-AuNp(av)=13,515 dm3 mol(-1) although no such phenomenon is observed in case of C60-1 system, viz., KC60-1(av)=1445 dm3 mol(-1) and KC60-1-AuNp(av)=1210 dm3 mol(-1). DLS study reveals sizeable amount of increase in the particle size of C70-1-AuNp nanocomposite, i.e., ∼105 nm, compared to C60-1-AgNp system, e.g., ∼5.5 nm which gives very good support in favor of decrease in the value of Kav for the former system. SEM study reveals that nanoparticles are dispersed in larger extent in case of C70-1-AuNp system. Time-resolved fluorescence study envisages that deactivation of the excited singlet state of 1 by C70 takes place at a faster rate in comparison to C60 in presence of gold nanoparticles.


Assuntos
Fulerenos/química , Ouro/química , Luz , Nanopartículas Metálicas/química , Porfirinas/química , Cinética , Nanopartículas Metálicas/ultraestrutura , Tamanho da Partícula , Fótons , Espalhamento de Radiação , Soluções , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Fatores de Tempo
13.
Artigo em Inglês | MEDLINE | ID: mdl-24291433

RESUMO

The present paper reports the photophysical insights on supramolecular interaction of a monoporphyrin derivative, namely, 1, with C60 pyrrolidine tris-acid ethyl ester (PyC60) in toluene and benzonitrile. The ground state interaction between PyC60 and 1 is facilitated through charge transfer interaction. Both UV-Vis and steady state measurements elicit almost similar magnitude of binding constant for the PyC60/1 complex in toluene and benzonitrile, viz., 6825 and 6540 dm(3 )mol(-1), respectively. Life time measurement evokes that rate of charge separation is fast in benzonitrile. Both hybrid-DFT and DFT calculations provide very good support in favor of electronic charge-separation in PyC60/1 system in vacuo.


Assuntos
Fenômenos Químicos , Elétrons , Fulerenos/química , Metaloporfirinas/química , Porfirinas/química , Pirrolidinas/química , Absorção , Cinética , Modelos Moleculares , Conformação Molecular , Teoria Quântica , Soluções , Solventes/química , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Eletricidade Estática , Fatores de Tempo , Titulometria
14.
Spectrochim Acta A Mol Biomol Spectrosc ; 117: 686-95, 2014 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-24128922

RESUMO

The photophysical features of non-covalently linked fullerenes C60 and C70 with a designed free-base phthalocyanine, namely, 2,3,9,10,16,17,23,24-octakis-(octyloxy)-29H,31H-phthalocyanine (1) have been investigated employing various spectroscopic tools like UV-vis absorption spectrophotometry, steady state and time resolved fluorescence along with proton NMR measurements in toluene. The ground state interaction between fullerenes and 1 is nicely demonstrated with the appearance of well defined charge transfer absorption bands in the visible region of the electronic spectra. Steady state fluorescence experiment reveals efficient quenching of the excited singlet state of 1 in presence of both C60 and C70. The average values of binding constants for the non-covalent complexes of C60 and C70 with 1 are determined to be ~18,150 and ~32,000 dm(3) mol(-1), respectively. The magnitude of K suggests that 1 preferentially binds C70 in comparison to C60 although average value of selectivity in binding is measured to be low (~1.75). Time resolved emission measurements establish photoinduced energy transfer from the excited singlet state of 1 to fullerene in toluene. Measurements of free energy of electron transfer and free energy of radical ion-pair formation elicit that C70/1 complex is stabilized more in comparison to C60/1 complex regarding generation of charge-separated state. Proton NMR studies provide very good support in favor of effective ground state complexation between fullerenes and 1. Semi empirical theoretical calculations on fullerene/1 systems in vacuo substantiate the stronger binding between C70 and 1 in comparison to C60/1 system in terms of heat of formation value of the respective complexes, and determine the orientation of bound guest (here C70) towards the plane of 1 during complexation.


Assuntos
Elétrons , Transferência de Energia , Fulerenos/química , Indóis/química , Fotoquímica , Isoindóis , Cinética , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Soluções , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta
15.
J Clin Diagn Res ; 8(11): FC08-10, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25584227

RESUMO

AIM: Age, sex, living place (urban or rural), smoking, alcohol consumption, dietary pattern, obesity are considered as risk factors for Colorectal cancer. Our study was done to evaluate the association between these risk factors and colorectal cancer in the population of North Bengal. MATERIALS AND METHODS: The present study was done over a period of one year as a hospital-based analytical observational type of study with cross-sectional type of study design. All the patients undergoing colorectal endoscopic biopsy at the Department of Surgery, NBMC&H during the study period for various clinical indications comprised the study population. History and clinical examination were done of the patients whose colorectal biopsy were taken and filled-up in a pre-designed pre-tested proforma. Significance was tested at 95% confidence interval. RESULTS: There is an increased risk of colorectal carcinoma (CRC) with increasing age in our study population. Odd's ratio for last 2 age groups are statistically significant with 2.83 for 41-50 years age group (95% CI is0.3-24), 13.6 for 51-60 years age group (95% CI is 2.1-85.9), 42.5 for more than 60 y age group patients (95% CI is 3.1-571). There is increased risk of colorectal carcinoma in males with an Odd's ratio of 1.6 (95% CI is 0.5-5.5), but it is not statistically significant. There was an increased urban incidence of colorectal carcinoma compared to rural population with an Odd's ratio of 1.8 (with a 95% CI of 0.6-5.9). In our study smoking also proved to be a risk factor and it is significant with an Odd's ratio of 5.4 with a 95% CI of 1.6-8.7. Odd's ratio for cases of alcohol consumption was 3.5 with a 95% CI of 1-11.6. Carcinoma cases were more common among patients with history of non-vegetarian dietary intake with Odds ratio of 1.5 (with a 95% CI of 0.3-8.7), but it was not statistically significant. Obesity has got a significant association with CRC in our study with an Odd's ratio of 7.2 (with 95% CI of 1.3-40.2). CONCLUSION: More than 50 years of age, smoking, obesity were significant risk factors in our study. Other risk factors were though not significant, but much more common in colorectal cancer patients compared to non-malignant population.

16.
J Clin Diagn Res ; 7(7): 1444-6, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23998088

RESUMO

Yolk sac tumour is the most common germ cell tumour in infants and children, with a majority of them arising in the gonads. Rare cases of extra - gonadal germ cell tumours have been described in the literature. We are presenting here, a case of a yolk sac tumour of the cryptorchid testis in a 2 year old child, who initially presented with a mass in the left lobe of the liver, with huge ascites and which posed diagnostic difficulties. The mass was diagnosed as hepatoblastoma on Computed Tomography (CT). Subsequently, CT guided Fine Needle Aspiration Cytology (FNAC) of the liver mass showed the features of a yolk sac tumour. The raised serum Alfa Foetoprotein (AFP) levels corroborated with the cytological diagnosis.

17.
Artigo em Inglês | MEDLINE | ID: mdl-23892346

RESUMO

The present work reports the photophysical insights behind effective non-covalent interaction between a designed diporphyrin (1) and fullerenes C60 and C70 in toluene. Ground state electronic interaction between fullerenes and 1 is evidenced from UV-Vis measurements in which it is observed that the intensity of the Soret absorption band of 1 is decreased considerably in presence of both C60 and C70. Steady state fluorescence studies reveal efficient quenching of the fluorescence intensity of 1 in presence of fullerenes. Evaluation of binding constants for the fullerene/1 systems evoke that 1 may be employed as an efficient molecular tweezers for C70 in toluene as selectivity in binding is determined to be ∼9.4. Time resolved emission studies establish relatively long-lived charge separated state for the C70/1 system in comparison to C60/1. Molecular mechanics calculations by force field method in vacuo interpret well regarding stability difference between C60 and C70 complexes of 1 and give formidable support in favor of side-on orientation motif of C70 towards the plane of 1 during non-covalent complexation process.


Assuntos
Fulerenos/química , Porfirinas/química , Cinética , Soluções , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Fatores de Tempo
18.
Artigo em Inglês | MEDLINE | ID: mdl-23747429

RESUMO

The present paper reports the role of silver nanoparticles, i.e., AgNp (having diameter ~5-15 nm), in non-covalent interaction between fullerenes (C60 and C70) and a designed bisporphyrin (1) in toluene. UV-Vis measurement reveals reduction in binding constant (K) values for both C60-1 (K(C60-1)=18,800 dm(3) mol(-1)) and C70-1 systems (K(C70-1)=27,300 dm(3) mol(-1)) in presence of AgNp, i.e., K(C60-1-AgNp 0=3700 dm(3) mol(-1) and K(C70-1-AgNp 0=1600 dm(3) mol(-1) for C(60)-1-AgNp and C(70)-1-AgNp nanocomposite, respectively. Dynamic light scattering study reveals considerable increase in the particle size of C(70)-1-AgNp nanocomposite, i.e., ~39 nm, compared to C(60)-1-AgNp, e.g., ~22 nm. Scanning electron microscope measurement reveals that the well arranged and composed structure of uncomplexed 1 is perturbed very much in presence of both C60 and C70, and it ultimately results into formation of nanoaggregate in case of C(70)-1-AgNp system. Transmission electron microscope study envisages formation of fibrous structure in presence of C60 and C70.


Assuntos
Fulerenos/química , Nanopartículas/química , Porfirinas/química , Prata/química , Sítios de Ligação , Nanopartículas/ultraestrutura , Tamanho da Partícula , Espectrofotometria Ultravioleta
19.
Artigo em Inglês | MEDLINE | ID: mdl-23501714

RESUMO

The present article reports, for the first time, the photophysical aspects of non-covalent interaction of a fullerene derivative, namely, C60 pyrrolidine tris-acid ethyl ester (PyC60) with a designed bisporphyrin (1) (having carbazole spacer unit) in toluene. Absorption spectrophotometric studies reveal that decrease in the absorption intensity of the Soret absorption band of 1 takes in presence of PyC60 in the solvent studied. Steady state fluorescence studies reveal efficient quenching of fluorescence intensity of 1 in presence of PyC60. Static quenching model explores a binding constant (KS) value of 2,910 dm(3) mol(-1) in toluene. Time resolved emission study establishes static quenching mechanism for the investigated supramolecule in non-polar solvent. Molecular mechanics calculations in vacuo evoke the single projection structure of the PyC60-1 complex and interpret the geometrical arrangement of both PyC60 and 1 during non-covalent complexation.


Assuntos
Fulerenos/química , Porfirinas/química , Pirrolidinas/química , Sítios de Ligação , Modelos Moleculares , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta
20.
Artigo em Inglês | MEDLINE | ID: mdl-23220678

RESUMO

The present paper reports non-covalent interaction between fullerenes (C(60) and C(70)) and a designed bisporphyrin (1) in p-xylene in absence and presence of silver nanoparticles (AgNp) having diameter ∼5-15 nm. Both UV-vis and fluorescence experiments reveal reduction in the average binding constant (K(av)) value for C(60)-1 (K(C60-)(1)=27,980 dm(3)mol(-1)) and C(70)-1 systems (K(C70-)(1)=115,020 dm(3)mol(-1)) in presence of AgNp, i.e., K(C60-)(1)(-AgNp)=22,465 dm(3)mol(-1) and K(C70-)(1)(-AgNp)=30,830 dm(3)mol(-1). Dynamic light scattering experiment gives clear indication regarding formation of larger aggregates as a result of electrostatic attraction between porphyrin-based supramolecule and AgNp in solution. Scanning electron microscope measurement reveals formation of molecular cluster comprising C(70)-1-AgNp composite.


Assuntos
Fulerenos/química , Nanopartículas/química , Porfirinas/química , Prata/química , Sítios de Ligação , Nanopartículas/ultraestrutura , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Xilenos/química
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