Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Angew Chem Int Ed Engl ; 62(20): e202213567, 2023 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-36894506

RESUMO

Reagent-free electronic biosensors capable of analyzing disease markers directly in unprocessed body fluids will enable the development of simple & affordable devices for personalized healthcare monitoring. Here we report a powerful and versatile nucleic acid-based reagent-free electronic sensing system. The signal transduction is based on the kinetics of an electrode-tethered molecular pendulum-a rigid double stranded DNA with one of the strands displaying an analyte-binding aptamer and the other featuring a redox probe-that exhibits field-induced transport modulated by receptor occupancy. Using chronoamperometry, which enables the sensor to circumvent the conventional Debye length limitation, the binding of an analyte can be monitored as these species increase the hydrodynamic drag. The sensing platform demonstrates a low femtomolar quantification limit and minimal cross-reactivity in analyzing cardiac biomarkers in whole blood collected from patients with chronic heart failure.


Assuntos
Aptâmeros de Nucleotídeos , Ácidos Nucleicos , Humanos , Aptâmeros de Nucleotídeos/química , DNA/química , Eletrodos , Biomarcadores
2.
Med J Armed Forces India ; 78(Suppl 1): S330-S334, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36147409

RESUMO

Gallbladder (GB) Small Cell Carcinoma (SCC) is an uncommon entity with very poor prognosis. There is a paucity of literature regarding its natural history and management, with only 73 prior cases reported in the world literature. In this case report, we present three cases of SCC of the GB with varied presentations, clinical course, management, and outcomes along with a brief review of the available literature on this subject.

3.
J Am Chem Soc ; 134(11): 5222-32, 2012 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-22385287

RESUMO

Conjugated polymers with nearly planar backbones have been the most commonly investigated materials for organic-based electronic devices. More twisted polymer backbones have been shown to achieve larger open-circuit voltages in solar cells, though with decreased short-circuit current densities. We systematically impose twists within a family of poly(hexylthiophene)s and examine their influence on the performance of polymer:fullerene bulk heterojunction (BHJ) solar cells. A simple chemical modification concerning the number and placement of alkyl side chains along the conjugated backbone is used to control the degree of backbone twisting. Density functional theory calculations were carried out on a series of oligothiophene structures to provide insights on how the sterically induced twisting influences the geometric, electronic, and optical properties. Grazing incidence X-ray scattering measurements were performed to investigate how the thin-film packing structure was affected. The open-circuit voltage and charge-transfer state energy of the polymer:fullerene BHJ solar cells increased substantially with the degree of twist induced within the conjugated backbone--due to an increase in the polymer ionization potential--while the short-circuit current decreased as a result of a larger optical gap and lower hole mobility. A controlled, moderate degree of twist along the poly(3,4-dihexyl-2,2':5',2''-terthiophene) (PDHTT) conjugated backbone led to a 19% enhancement in the open-circuit voltage (0.735 V) vs poly(3-hexylthiophene)-based devices, while similar short-circuit current densities, fill factors, and hole-carrier mobilities were maintained. These factors resulted in a power conversion efficiency of 4.2% for a PDHTT:[6,6]-phenyl-C(71)-butyric acid methyl ester (PC(71)BM) blend solar cell without thermal annealing. This simple approach reveals a molecular design avenue to increase open-circuit voltage while retaining the short-circuit current.

4.
J Org Chem ; 77(13): 5544-51, 2012 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-22621328

RESUMO

2,6-Diacyl derivatives of naphthalene-1,8:4,5-bis(dicarboximide)s have been synthesized via Stille coupling reactions of the corresponding 2,6-distannyl derivative with acyl halides. Reaction of these diketones with hydrazine gave phthalazino[6,7,8,1-lmna]pyridazino[5,4,3-gh][3,8]phenanthroline-5,11(4H,10H)-dione fused-ring derivatives. The products were characterized by UV-vis absorption spectroscopy and electrochemistry, modeled using density functional theory calculations, and, in some cases, studied and compared using single-crystal X-ray diffraction.


Assuntos
Hidrocarbonetos Halogenados/química , Imidas/química , Naftalenos/química , Compostos Orgânicos de Estanho/química , Cristalografia por Raios X , Modelos Moleculares , Oxirredução , Teoria Quântica
5.
Phys Chem Chem Phys ; 14(41): 14243-8, 2012 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-22914764

RESUMO

Polymers with low optical gaps are of importance to the organic photovoltaics community due to their potential for harnessing a large portion of the solar energy spectrum. The combination along their backbones of electron-rich and electron-deficient fragments contributes to the presence of low-lying excited states that are expected to display significant charge-transfer character. While conventional hybrid functionals are known to provide unsatisfactory results for charge-transfer excitations at the time-dependent DFT level, long-range corrected (LRC) functionals have been reported to give improved descriptions in a number of systems. Here, we use such LRC functionals, considering both tuned and default range-separation parameters, to characterize the absorption spectra of low-optical-gap systems of interest. Our results indicate that tuned LRC functionals lead to simulated optical-absorption properties in good agreement with experimental data. Importantly, the lowest-lying excited states (excitons) are shown to present a much more localized nature than initially anticipated.

6.
3 Biotech ; 12(1): 20, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34956813

RESUMO

This study aimed at energy reduction during pulping of L. leucocephala by passing the wood chips through an impressafiner followed by xylanase pretreatment. An impressafiner compressed the chips and converted them into spongy materials. Wood chips of L. leucocephala with or without de-structuring and de-structured wood chips followed by enzymatic treatment were subjected to Kraft pulping at different temperatures varying from 135 to 170 °C and active alkali varying from 12 to 20% (as Na2O) to observe effect on screened pulp yield and kappa number. The de-structured wood chips followed by enzymatic treatment produced a pulp yield of 48.2% and kappa number 18.6. L. leucocephala without de-structuring produced a pulp yield of 50.1% and kappa number 23.7. When the pulp was subjected to oxygen delignification to reduce kappa number in the vicinity of 18.6, pulp showed shrinkage by 6.64% compared to Kraft pulp of de-structured wood chips followed by enzymatic treatment. Kraft pulp produced from de-structured wood chips of L. leucocephala followed by enzymatic treatment showed net saving of US$ 163.15 per digester over Kraft pulp produced without de-structuring of wood chips of L. leucocephala. Moreover, the pulp obtained by de-structuring followed by enzymatic treatment showed improvement in pulp brightness and physical strength properties including tensile, tear, and burst index significantly compared to pulp obtained without de-structuring.

7.
J Ayurveda Integr Med ; 12(1): 126-130, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33637425

RESUMO

BACKGROUND: The use of complementary and alternative medicine (CAM) is widespread among cancer patients in India. OBJECTIVE: The present study elucidated usage patterns of CAM and the factors responsible for its adoption among the patients with cancer, and the therapeutic impact of CAM. MATERIALS AND METHODS: This was a questionnaire-based study, conducted among patients with cancer in a tertiary care hospital in a sub-Himalayan city. Data were analyzed using statistical methods. RESULTS: A total of 2614 patients with cancer were included. Almost half of the patients (n = 1208, 46.2%) reported to have been treated with CAM. Breast cancer (n = 274, 23.0%) was most prevalent with majority at advanced stages. Ayurveda (n = 428, 35.9%) Yoga/Naturopathy (n = 381, 32.0%) Homeopathy (n = 143, 12.0%) and Unani (n = 71, 5.9%) were used commonly. Among CAM users, 85.0% (n = 1012) of patients used CAM as the sole method of treatment, while 58.9% (n = 702) patients reported initial symptomatic benefit. CONCLUSION: Using CAM benefitted a significant number of patients with cancer. However, there is an urgent need to integrate CAM with modern system of medicine.

8.
BMJ Case Rep ; 13(11)2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33229486

RESUMO

Primary synovial sarcoma of the lung (PSSL) is a rare tumour with only 0.5% incidence among other primary malignant lung tumours. Published medical literature regarding the natural history treatment protocol and clinical outcomes of PSSL remains limited. Here, we present a case of a 39-year-old man with primary synovial sarcoma with long-term follow-up, which was initially viewed as a metastasis from another unknown site. After evaluating histopathologically from the specimen post left lung metastasectomy and ruling out any other site for neoplastic changes, the diagnosis of PSSL was confirmed. Furthermore, this article reviews the literature and discusses various aspects of PSSL, including clinical presentation, radiological imaging and pathological characteristics, diagnostic dilemma, management and prognosis. This paper serves to provide an update and aims to enhance the understanding of PSSL. Timely diagnosis and treatment are imperative to achieve improved outcomes.


Assuntos
Neoplasias Pulmonares/diagnóstico , Pulmão/diagnóstico por imagem , Sarcoma Sinovial/diagnóstico , Adulto , Biópsia , Diagnóstico Diferencial , Humanos , Neoplasias Pulmonares/cirurgia , Masculino , Metastasectomia , Metástase Neoplásica , Pneumonectomia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Sarcoma Sinovial/secundário , Sarcoma Sinovial/cirurgia
9.
Radiat Oncol J ; 38(2): 93-98, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33012152

RESUMO

PURPOSE: Due to COVID 19 pandemic, the treatment of cancer patients has become a dilemma for every oncologist. Cancer patients are at an increased risk of immunosuppression and have a higher risk to acquire any infection. There are individual experiences from some centers regarding the management of cancer patients during such a crisis. So we have developed our institutional strategy to balance between COVID and cancer management. MATERIALS AND METHODS: Radiation Oncology departmental meeting was held to prepare a consensus document on Radiotherapy schedules and department functioning during this pandemic. RESULTS: Strategies were taken in form of following areas were steps need to be taken to decrease risk of infection, categorise treatment on the basis of priority, radiotherapy schedules modification, academic meetings and management of COVID positive patient/personnel in Radiation Oncology department. CONCLUSION: We hope to strike the balance in overcoming both the battles and emerge as winners. Stringent long term follow up will be done for assessing the response or any unforeseen treatment related sequelae.

13.
Dalton Trans ; (39): 4654-6, 2006 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-17028672

RESUMO

Both pentafluorophenylmercury chloride and trimeric perfluoro-ortho-phenylene mercury interact with phenanthrene to form phosphorescent adducts which exhibit extended binary stacks in the solid state.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA