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1.
NPJ Precis Oncol ; 8(1): 63, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38438481

RESUMO

Head and neck cancer is a major cause of morbidity and mortality worldwide. The identification of genetic alterations in head and neck cancer may improve diagnosis and treatment outcomes. In this study, we report the identification and functional characterization of UBE3C-LRP5 translocation in head and neck cancer. Our whole transcriptome sequencing and RT-PCR analysis of 151 head and neck cancer tumor samples identified the LRP5-UBE3C and UBE3C-LRP5 fusion transcripts in 5.3% of patients of Indian origin (n = 151), and UBE3C-LRP5 fusion transcripts in 1.2% of TCGA-HNSC patients (n = 502). Further, whole genome sequencing identified the breakpoint of UBE3C-LRP5 translocation. We demonstrate that UBE3C-LRP5 fusion is activating in vitro and in vivo, and promotes the proliferation, migration, and invasion of head and neck cancer cells. In contrast, depletion of UBE3C-LRP5 fusion suppresses the clonogenic, migratory, and invasive potential of the cells. The UBE3C-LRP5 fusion activates the Wnt/ß-catenin signaling by promoting nuclear accumulation of ß-catenin, leading to upregulation of Wnt/ß-catenin target genes, MYC, CCND1, TCF4, and LEF1. Consistently, treatment with the FDA-approved drug, pyrvinium pamoate, significantly reduced the transforming ability of cells expressing the fusion protein and improved survival in mice bearing tumors of fusion-overexpressing cells. Interestingly, fusion-expressing cells upon knockdown of CTNNB1, or LEF1 show reduced proliferation, clonogenic abilities, and reduced sensitivity to pyrvinium pamoate. Overall, our study suggests that the UBE3C-LRP5 fusion is a promising therapeutic target for head and neck cancer and that pyrvinium pamoate may be a potential drug candidate for treating head and neck cancer harboring this translocation.

2.
Angew Chem Int Ed Engl ; 63(18): e202401136, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38379203

RESUMO

The development of artificial light-harvesting systems mimicking the natural photosynthesis method is an ever-growing field of research. Numerous systems such as polymers, metal complexes, POFs, COFs, supramolecular frameworks etc. have been fabricated to accomplish more efficient energy transfer and storage. Among them, the supramolecular coordination complexes (SCCs) formed by non-covalent metal-ligand interaction, have shown the capacity to not only undergo single and multistep energy migration but also to utilize the harvested energy for a wide variety of applications such as photocatalysis, tunable emissive systems, encrypted anti-counterfeiting materials, white light emitters etc. This review sheds light on the light-harvesting behavior of both the 2D metallacycles and 3D metallacages where design ingenuity has been executed to afford energy harvesting by both donor ligands as well as metal acceptors.

3.
BMC Public Health ; 24(1): 299, 2024 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-38273246

RESUMO

BACKGROUND: Patients with TB have additional nutritional requirements and thus additional costs to the household. Ni-kshay Poshan Yojana(NPY) is a Direct Benefit Transfer (DBT) scheme under the National Tuberculosis Elimination Programme(NTEP) in India which offers INR 500 monthly to all notified patients with TB for nutritional support during the period of anti-TB treatment. Five years after its implementation, we conducted the first nationwide evaluation of NPY. METHODS: In our retrospective cohort study using programmatic data of patients notified with TB in nine randomly selected Indian states between 2018 and 2022, we estimated the proportion of patients who received at least one NPY instalment and the median time to receive the first instalment. We determined the factors associated (i) with non-receipt of NPY using a generalised linear model with Poisson family and log link and (ii) with time taken to receive first NPY benefit in 2022 using quantile regression at 50th percentile. RESULTS: Overall, 3,712,551 patients were notified between 2018 and 2022. During this period, the proportion who received at least one NPY instalment had increased from 56.9% to 76.1%. Non-receipt was significantly higher among patients notified by private sector (aRR 2.10;2.08,2.12), reactive for HIV (aRR 1.69;1.64,1.74) and with missing/undetermined diabetic status (aRR 2.02;1.98,2.05). The median(IQR) time to receive the first instalment had reduced from 200(109,331) days in 2018 to 91(51,149) days in 2022. Patients from private sector(106.9;106.3,107.4days), those with HIV-reactive (103.7;101.8,105.7days), DRTB(104.6;102.6,106.7days) and missing/undetermined diabetic status (115.3;114,116.6days) experienced longer delays. CONCLUSIONS: The coverage of NPY among patients with TB had increased and the time to receipt of benefit had halved in the past five years. Three-fourths of the patients received at least one NPY instalment, more than half of whom had waited over three months to receive the first instalment. NTEP has to focus on timely transfer of benefits to enable patients to meet their additional nutritional demands, experience treatment success and avoid catastrophic expenditure.


Assuntos
Diabetes Mellitus , Soropositividade para HIV , Humanos , Estudos Retrospectivos , Apoio Nutricional , Índia/epidemiologia
4.
Glob Health Action ; 16(1): 2256129, 2023 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-37732993

RESUMO

BACKGROUND: India has been implementing active case-finding (ACF) for TB among marginalised and vulnerable (high-risk) populations since 2017. The effectiveness of ACF cycle(s) is dependent on the use of appropriate screening and diagnostic tools and meeting quality indicators. OBJECTIVES: To determine the number of ACF cycles implemented in 2021 at national, state (n = 36) and district (n = 768) level and quality indicators for the first ACF cycle. METHODS: In this descriptive study, aggregate TB program data for each ACF activity that was extracted was further aggregated against each ACF cycle at the district level in 2021. One ACF cycle was the period identified to cover all the high-risk populations in the district. Three TB ACF quality indicators were calculated: percentage population screened (≥10%), percentage tested among screened (≥4.8%) and percentage diagnosed among tested (≥5%). We also calculated the number needed to screen (NNS) for diagnosing one person with TB (≤1538). RESULTS: Of 768 TB districts, ACF data for 111 were not available. Of the remaining 657 districts, 642 (98%) implemented one, and 15 implemented two to three ACF cycles. None of the districts or states met all three TB ACF quality indicators' cut-offs. At the national level, for the first ACF cycle, 9.3% of the population were screened, 1% of the screened were tested and 3.7% of the tested were diagnosed. The NNS was 2824: acceptable (≤1538) in institutional facilities and poor for population-based groups. Data were not consistently available to calculate the percentage of i) high-risk population covered, ii) presumptive TB among screened and iii) tested among presumptive. CONCLUSION: In 2021, India implemented one ACF cycle with sub-optimal ACF quality indicators. Reducing the losses between screening and testing, improving data quality and sensitising stakeholders regarding the importance of meeting all ACF quality indicators are recommended.


Assuntos
Análise de Dados Secundários , Tuberculose , Humanos , Tuberculose/diagnóstico , Tuberculose/epidemiologia , Tuberculose/prevenção & controle , Confiabilidade dos Dados , Instalações de Saúde , Índia/epidemiologia
5.
Eur Biophys J ; 52(1-2): 91-100, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36929427

RESUMO

Lithium has been the treatment of choice for patients with bipolar disorder. However, lithium overdose happens more frequently since it has a very narrow therapeutic range in blood, necessitating investigation of its adverse effects on blood cells. The possible changes that lithium exposure may have on functional and morphological characteristics of human red blood cells (RBCs) have been studied ex vivo using single-cell Raman spectroscopy, optical trapping, and membrane fluorescent probe. The Raman spectroscopy was performed with excitation at 532 nm light, which also results in simultaneous photoreduction of intracellular hemoglobin (Hb). The level of photoreduction of lithium-exposed RBCs was observed to decline with lithium concentration, indicating irreversible oxygenation of intracellular Hb from lithium exposure. The lithium exposure may also have an effect on RBC membrane, which was investigated via optical stretching in a laser trap and the results suggest lower membrane fluidity for the lithium-exposed RBCs. The membrane fluidity of RBCs was further studied using the Prodan generalized polarization method and the results verify the reduction of membrane fluidity upon lithium exposure.


Assuntos
Eritrócitos , Lítio , Humanos , Lítio/farmacologia , Lítio/análise , Eritrócitos/química , Hemoglobinas , Lasers , Análise Espectral Raman
6.
BMJ Open ; 12(7): e060197, 2022 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-35902192

RESUMO

OBJECTIVES: We verified subnational (state/union territory (UT)/district) claims of achievements in reducing tuberculosis (TB) incidence in 2020 compared with 2015, in India. DESIGN: A community-based survey, analysis of programme data and anti-TB drug sales and utilisation data. SETTING: National TB Elimination Program and private TB treatment settings in 73 districts that had filed a claim to the Central TB Division of India for progress towards TB-free status. PARTICIPANTS: Each district was divided into survey units (SU) and one village/ward was randomly selected from each SU. All household members in the selected village were interviewed. Sputum from participants with a history of anti-TB therapy (ATT), those currently experiencing chest symptoms or on ATT were tested using Xpert/Rif/TrueNat. The survey continued until 30 Mycobacterium tuberculosis cases were identified in a district. OUTCOME MEASURES: We calculated a direct estimate of TB incidence based on incident cases identified in the survey. We calculated an under-reporting factor by matching these cases within the TB notification system. The TB notification adjusted for this factor was the estimate by the indirect method. We also calculated TB incidence from drug sale data in the private sector and drug utilisation data in the public sector. We compared the three estimates of TB incidence in 2020 with TB incidence in 2015. RESULTS: The estimated direct incidence ranged from 19 (Purba Medinipur, West Bengal) to 1457 (Jaintia Hills, Meghalaya) per 100 000 population. Indirect estimates of incidence ranged between 19 (Diu, Dadra and Nagar Haveli) and 788 (Dumka, Jharkhand) per 100 000 population. The incidence using drug sale data ranged from 19 per 100 000 population in Diu, Dadra and Nagar Haveli to 651 per 100 000 population in Centenary, Maharashtra. CONCLUSION: TB incidence in 1 state, 2 UTs and 35 districts had declined by at least 20% since 2015. Two districts in India were declared TB free in 2020.


Assuntos
Monitoramento Epidemiológico , Tuberculose , Erradicação de Doenças , Humanos , Incidência , Índia/epidemiologia , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/diagnóstico , Tuberculose/epidemiologia , Tuberculose/prevenção & controle
7.
Eur Biophys J ; 50(6): 867-876, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34110463

RESUMO

Management of postprandial hyperglycemia is important for preventing severe complications like cardiovascular disease in diabetes patients. The associated glycemic instability in postprandial hyperglycemia may also cause disorders in circulating red blood cells (RBCs). Therefore, effects of short-term hyperglycemic stress on RBCs such as occur in the postprandial condition, have been studied here ex vivo using single-cell Raman spectroscopy and optical trapping. RBCs incubated in high glucose containing media relevant to postprandial hyperglycemia were studied for changes with respect to controls by analyzing the single-cell Raman spectra acquired with Raman optical tweezers with 532 nm excitation light. Use of 532 nm light for exciting Raman spectra also results in simultaneous photoreduction of intracellular hemoglobin (Hb). The level of photoreduction was noticed to be limited in hyperglycemia-exposed cells in comparison to the control. Since this suggests formation of permanently oxidized Hb in hyperglycemia-exposed RBCs, a fluorescence study was performed which showed elevated levels of oxidative stress in these cells. The changes in the RBC membrane, which may result due to higher levels of oxidative stress, were investigated using optical stretching experiments under the laser trap. The results indicated a loss of elasticity for the RBC membrane due to hyperglycemic exposure.


Assuntos
Hiperglicemia , Pinças Ópticas , Eritrócitos/química , Hemoglobinas , Humanos , Análise Espectral Raman
8.
J Biophotonics ; 14(8): e202100047, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33871929

RESUMO

Raman spectroscopy was performed on GSM 900 and 1800 MHz mobile phone signal exposed red blood cells (RBCs). The observed changes in the Raman spectra of mobile signal exposed RBCs compared to unexposed control suggest reduced hemoglobin-oxygen affinity for the exposed cells. The possible mechanism may involve activation of the voltage gated membrane Ca2+ channels by the mobile phone emissions resulting in an increase in the levels of adenosine triphosphate (ATP) and 2,3-diphosphoglycerate (2,3-DPG) in cells via altered metabolic activities. Further studies carried out with fluorescent Ca2+ indicator confirmed increased intracellular Ca2+ level in the exposed cells. Since intracellular ATP level influences the shape and mechanics of RBCs, exposed cells were studied using diffraction phase microscopy and optical tweezers. Detectable changes in shape and mechanical properties were observed due to mobile signal exposure.


Assuntos
Telefone Celular , Eritrócitos , Contagem de Eritrócitos , Hemoglobinas , Humanos , Pinças Ópticas
9.
Inorg Chem ; 59(3): 2083-2091, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-31971781

RESUMO

Control over the stimuli-responsive behavior of smart molecular systems can influence their capability to execute complex functionalities. Herein, we report the development of a suite of spiropyran-based multi-stimuli-responsive self-assembled platinum(II) macrocycles (5-7), rendering coordination-assisted enhanced photochromism relative to the corresponding ligands. 5 showed shrinking and swelling during photoreversal, while 6 and 7 are fast and fatigue-free supramolecular photoswitches. 6 turns out to be a better fatigue-resistant photoswitch and can retain an intact photoswitching ability of up to 20 reversible cycles. The switching behavior of the macrocycles can also be precisely controlled by tuning the pH of the medium. Our present strategy for the construction of rapid stimuli-responsive supramolecular architectures via coordination-driven self-assembly represents an efficient route for the development of smart molecular switches.

10.
Inorg Chem ; 58(6): 3968-3981, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-30810042

RESUMO

A series of self-assembled functional Pt(II) molecular hexagons (M1-M3) is reported. Hexagons M1 and M2 were designed employing aggregation induced emissive and photochromic building blocks, respectively, while macrocycle M3 is a bifunctional, containing both the kinds of building units. Hexagons M1 and M3 were found to inherit the enhanced emission with aggregate formation which was explored using UV-vis and fluorescence spectroscopy. The enhanced emission of macrocycle M3 compared to that of its building units was driven both by metal-ligand coordination and formation of nanoaggregates as evident from SEM, DLS and TEM analyses. Two of the macrocycles (M2 and M3) were also found to be photochromic due to the presence of spiropyran in the molecular backbone. Due to the virtue of protonation-deprotonation equilibrium of the spiropyran, these macrocycles (M2 and M3) showed reversible acidochromic behavior. Macrocycle M3 represents the first example of a self-assembled Pt(II) architecture which is multifunctional with aggregation-induced emission (AIE), photochromic, and acidochromic properties. This new generation macrocycle (M3) also showed coordination-driven enhanced emission and light-induced color change behavior compared to the starting building blocks. Our present approach of incorporating multiple functions into a single self-assembled structure with enhanced functionality compared to the starting building blocks via coordination self-assembly is noteworthy and has huge potential for the development of multifunctional materials.

11.
J Biophotonics ; 12(5): e201800246, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30666814

RESUMO

Simultaneous photoreduction and Raman spectroscopy with 532 nm laser has been used to study the effects of organophosphate (chlorpyrifos [CPF]) exposure on human red blood cells (RBCs). Since in RBCs, auto-oxidation causes oxidative stress, which, in turn, is balanced by the cellular detoxicants, any possible negative effect of CPF on this balance should results in an increased level of damaged (permanently oxygenated) hemoglobin. Therefore, when 532 nm laser, at a suitable power, was applied to photoreduce the cells, only common oxygenated form of hemoglobin got photoreduced leaving the permanently oxygenated hemoglobin detectable in the Raman spectra simultaneously excited by the same laser. Using the technique effects of CPF to build up oxidative stress on RBCs could be detected at concentrations as low as 10 ppb from a comparison of relative strengths of different Raman bands. Experiments performed using simultaneously exposing the cells, along with CPF, to H2 O2 (oxidative agent) and/or 3-Aminotriazole (inhibitor of anti-oxidant catalase), suggested role of CPF to suppress the cellular anti-oxidant mechanism. Since the high level of damaged hemoglobin produced by the action of CPF (at concentrations >100 ppm) is expected to cause membrane damage, atomic force microscopy (AFM) was used to identify such damages.Upper panel: Raman spectra of normal, photoreduced CPF exposed and unexposed RBCs. Lower panel: The weak Fe-O2 Raman band for CPF exposed cells shown on the left. The AFM images of unexposed and exposed cells are shown on the right. Scale bar, 2.5 µm.


Assuntos
Clorpirifos/toxicidade , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Processos Fotoquímicos/efeitos dos fármacos , Análise Espectral Raman , Humanos
12.
J Biophotonics ; 11(8): e201700222, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29498486

RESUMO

Rapid membrane damage of optically trapped red blood cells (RBCs) was observed at trapping powers ≥280 mW. An excellent agreement between the estimated laser-induced thermal gradient across trapped cell's membrane and that typically required for membrane electropermeabilization suggests a mechanism involving temperature gradient-induced electropermeabilization of membrane. Also the rapid collapse of the trapped cell due to membrane rupture was seen to cause shock waves in the surroundings permeabilizing nearby untrapped cells. When the experiments were carried out with RBCs collected from type II diabetic patients, a noticeable change in the damage rate compared to normal RBCs was seen suggesting a novel optical diagnosis method for the disease.


Assuntos
Membrana Celular/efeitos da radiação , Eritrócitos/citologia , Eritrócitos/efeitos da radiação , Luz/efeitos adversos , Pinças Ópticas , Temperatura , Animais , Células CHO , Membrana Celular/metabolismo , Cricetulus , Diabetes Mellitus/sangue , Hemoglobinas/metabolismo , Humanos
13.
ACS Omega ; 3(10): 13757-13771, 2018 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31458076

RESUMO

Two new star-shaped phenyl- and triazine-core based donor-acceptor (D-A) type conjugated molecules bearing triphenylamine end-capped arms were synthesized and characterized as imminent organic optoelectronic materials. Photophysical properties of the compounds were explored systematically via spectroscopic and theoretical methods. Because of the presence of donor-acceptor interactions, these luminogens display multifunctional properties, for instance, high extinction coefficient, large stokes shift, and pronounced solvatochromic effect. The compounds also exhibited phenomenon known as aggregation-induced emission on formation of nano-aggregates in the tetrahydrofuran-water mixture. The aggregate formation was confirmed by transmission electron microscopy, scanning electron microscopy, and dynamic light scattering analyses. Moreover, by controlling the electron withdrawing ability of the acceptor, complementary emissive fluorophores (blue and yellow) were achieved. These two complementary colors together span the entire range of visible spectrum (400-800 nm) and therefore when mixed in a requisite proportion generate white light in solution phase. These findings have potential for the progress of new organic white light radiating materials for applications in lighting and display devices.

14.
J Biomed Opt ; 22(10): 1-9, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29055124

RESUMO

Shape variations of red blood cells (RBCs) are known to occur upon exposure to various drugs or under diseased conditions. The commonly observed discocytic RBCs can be transformed to echinocytic or stomatocytic shape under such conditions. Raman spectra of the three major shape variations, namely discocyte, echinocyte, and stomatocyte, of RBCs were studied while subjecting the cells to oxygenated and deoxygenated conditions. Analysis of the recorded spectra suggests an increased level of hemoglobin (Hb)-oxygen affinity for the echinocytes. Also, some level of Hb degradation could be noticed for the deoxygenated echinocytes. The effects may arise from a reduced level of intracellular adenosine triphosphate in echinocytic cells and an increased fraction of submembrane Hb.


Assuntos
Forma Celular , Eritrócitos/citologia , Eritrócitos/metabolismo , Hemoglobinas/metabolismo , Oxigênio/metabolismo , Trifosfato de Adenosina , Humanos , Análise Espectral Raman
15.
Chemistry ; 23(35): 8482-8490, 2017 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-28378524

RESUMO

Morphology of nanomaterials has a strong impact on their chemical/physical properties, and controlled synthesis of such materials with desirable morphology is a major challenge. This article presents the role of a building block in the morphology of organic cage particles. In this context, three organic cages (A3 X2 , B3 X2 , and C3 X2 ) were devised from triphenylamine-based dialdehydes (A-C) and a flexible triamine (X) by utilizing dynamic imine chemistry. All of the synthesized cages were characterized by various spectroscopic techniques, which suggested the formation of [3+2] assembled architectures. Though the cages are isostructural, structural variation in the aldehyde building blocks imparted by the incorporation of phenyl moieties into the triphenylamine core produces morphologically diverse cage particles, as indicated by SEM. The synthesized cages were found to be fluorescent; the reduced analogue of cage A3 X2 (A3 X2r ) was tested to explore its use as a chemosensor for the detection of nitroaromatic explosives. The experimental findings suggest high selectivity and sensitivity of A3 X2r towards picric acid (PA) among the various nitroaromatics tested. A theoretical investigation of fluorescence quenching suggested that formation of a ground-state charge-transfer complex with a resonance energy-transfer (RET) process could be the main reason behind such selectivity of the cage towards PA.

16.
Appl Opt ; 56(3): 439-445, 2017 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-28157894

RESUMO

Adaptation of red blood cells subjected to acute hypoxia, crucial for managing high altitude syndrome and pulmonary diseases, has been investigated. For this, red blood cells were exposed to the acute hypoxic condition by purging nitrogen over increasing time periods from 15 to 60 min and thereafter equilibrated with atmospheric oxygen for 10 min. Raman spectra of these red blood cells were then recorded and analyzed to look for changes in the level of oxygenation compared to unexposed cells. A decreasing oxygen affinity for the cells was observed with increasing time of exposure to the hypoxic condition. This change in oxygen affinity for the red blood cells may result from metabolic adjustment of the cells under the hypoxic condition to promote increased concentration of intracellular 2, 3-diphosphoglycerate.


Assuntos
Eritrócitos/fisiologia , Hipóxia/fisiopatologia , Oxigênio/metabolismo , Aclimatação , Humanos , Nitrogênio , Oxigênio/sangue , Análise Espectral Raman
17.
Chemistry ; 22(22): 7468-78, 2016 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-27106871

RESUMO

Two new acceptors containing platinum-carbazole (1) and platinum-triphenylamine (2) backbones with bite angles of 90° and 120°, respectively, have been synthesised and characterised. Reactions of the rigid acceptor 1 with linear dipyridyl-based donors (3 and 4) generated [4+4] self-assembled molecular squares (5 and 6), and similar treatments with acceptor 2 instead of 1 yielded [6+6] self-assembled molecular hexagons (7 and 8). The metallacycles were characterised by multinuclear NMR spectroscopy ((1) H and (31) P) and ESI-MS. The geometries of the metallacycles were optimised by using the PM6 method. When aggregates of the metallacycles were formed by adding hexane solutions in dichloromethane, aggregation-induced emission was observed for metallacycles 5 and 7, and aggregation-caused quenching was observed for metallacycles 6 and 8. The formation of aggregates was verified by dynamic light scattering and TEM analyses. Macrocycles 5 and 7 are white-light emitters in THF. Moreover, their high luminescence in both solution and the solid state was utilised for the recognition of nitroaromatic explosives.

18.
Inorg Chem ; 55(4): 1562-8, 2016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26831376

RESUMO

Three new ditopic imidazole ligands (2-4) were synthesized in high yields and characterized by various spectroscopic techniques. These ligands resulted in the formation of [3 + 6] self-assembled trinuclear barrels (5-7) in quantitative yields by stoichiometric combination of individual ligands and Pd(NO3)2 in DMSO. All the three assemblies (5-7) were characterized by (1)H NMR and ESI-MS analysis, and subsequently, structures of the complexes 5 and 6 were confirmed by single-crystal X-ray diffraction studies. Structure analysis reveals the presence of NO3(-) counteranions in the intermolecular channels/pockets, which could potentially act as H-bonding sites between adsorbed water molecules within the channels. In fact, both the assemblies (5 and 6) showed water uptake (136.58, and 123.78 cm(3) g(-1), respectively) at ambient temperature under maximum allowable humidity. In addition, free aldehyde group present in the bridging ligand in complex 7 provides reactive site for postassembly modification. Herein, Knoevenagel condensation with Meldrum's acid was utilized under mild conditions by targeting aldehyde group appended in prefabricated complex 7 and transformed into a different complex (8) with altered functional group. Such postassembly functionalization enables incorporation of a new functional group without disrupting the integrity of the trifacial structure.

19.
Analyst ; 141(4): 1339-46, 2016 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-26738697

RESUMO

We report the results of our investigations on the use of Raman optical tweezers for label free analysis of cells in different phases of their cell cycle. The studies performed on human colon adenocarcinoma (Colo-205) cells synchronized in G0/G1 and G2/M phases showed that the DNA Raman band at 783 cm(-1) in the Raman spectra of optically trapped cells can provide information about the DNA content in the nucleus of the cell without the need for the isolation of the nucleus. The histograms of intensity of this band among the cell populations were found to corroborate the results obtained from fluorescence image cytometry performed on DAPI stained cells.


Assuntos
Ciclo Celular , Pinças Ópticas , Linhagem Celular Tumoral , Humanos , Microscopia de Fluorescência
20.
Chemistry ; 22(4): 1424-34, 2016 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-26748733

RESUMO

A new triphenylamine-based organometallic Pt(II) luminogen (1) and its analogous organic compound (2) are reported. The molecules are decorated with aldehyde functionality to improve their photophysical properties by utilising donor-acceptor interactions. The single crystal X-ray structure analysis of Pt(II) analogue 1 revealed that the neighbouring molecules were loosely organised by weak intermolecular C-H⋅⋅⋅π interactions. Because of the twisted nature of the triphenylamine backbone the compounds showed aggregation-induced emission enhancement in THF/water mixture. Due to their loose crystal packing, upon application of external stimuli these luminogens exhibited mechano-fluorochromic behaviour. The crystalline forms of the compounds displayed a more superior emission efficiency than the grinded samples. Moreover, the compounds showed crystallization-induced emission enhancement (CIEE) and exhibited chemodosimetric response towards cysteine under physiological condition.


Assuntos
Compostos de Anilina/química , Cisteína/química , Compostos Organoplatínicos/química , Cristalização , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estrutura Molecular
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