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The Potential Pharmacological Effects of Natural Product Withaferin A in Cancer: Opportunities and Challenges for Clinical Translation. PLANTA MEDICA 2024; 90:440-453. [PMID: 38588695 DOI: 10.1055/a-2289-9600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
Cancer is one of the biggest health concerns with a complex pathophysiology. Currently, available chemotherapeutic drugs are showing deleterious side effects, and tumors often show resistance to treatment. Hence, extensive research is required to develop new treatment strategies to fight against cancer. Natural resources from plants are at the forefront of hunting novel drugs to treat various types of cancers. Withaferin A (WA) is a naturally occurring withanolide, a biologically active component obtained from the plant Ashwagandha. Various in vitro and in vivo oncological studies have reported that Withaferin A (WA) has shown protection from cancer. WA shows its activity by inhibiting the growth and proliferation of malignant cells, apoptosis, and inhibiting angiogenesis, metastasis, and cancer stem cells (CSCs). In addition, WA also showed chemo- and radio-sensitizing properties. Besides the beneficiary pharmacological activities of WA, a few aspects like pharmacokinetic properties, safety, and toxicity studies are still lacking, hindering this potent natural product from entering clinical development. In this review, we have summarized the various pharmacological mechanisms shown by WA in in vitro and in vivo cancer studies and the challenges that must be overcome for this potential natural product's clinical translation to be effective.
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Oxygen-Isotope Exchange between CO 2 and NO 2 with Implications for Atmospheric Chemistry. J Phys Chem Lett 2024; 15:4430-4436. [PMID: 38626390 DOI: 10.1021/acs.jpclett.4c00485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/18/2024]
Abstract
Elucidating isotope exchange between atmospheric trace molecular species is important for environment monitoring, climate control studies, and a fundamental understanding of atmospheric chemistry. Here, we provide direct experimental evidence of oxygen-isotopic exchange between carbon dioxide (CO2) and nitrogen dioxide (NO2), which are simultaneously emitted into the atmosphere from common sources. A combined near-infrared and UV-vis optical cavity-enhanced experimental investigation along with quantum-chemical calculations followed by a reaction modeling study revealed that CO2 and NO2 can communicate isotopically by near-ultraviolet-driven NO2 photolysis. Our results found evidence for a near-barrierless (1.67 kcal/mol) nitrate-containing complex having a very short lifetime (∼13 ns) which facilitates the transfer of 18O-isotopes from 18O12C16O to N16O16O, leading to isotopic depletion of 18O in 18O12C16O, thus opening a new gas-phase isotope-selective chemical transformation mechanism in the lower atmosphere. This isotope exchange study may serve as a new window into the fundamental understanding of isotopic photochemistry, oxygen isotopic fractionations, and climate modeling.
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Imperative connotation of SODs in cancer: Emerging targets and multifactorial role of action. IUBMB Life 2024. [PMID: 38600696 DOI: 10.1002/iub.2821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 03/14/2024] [Indexed: 04/12/2024]
Abstract
Superoxide dismutase (SOD) is a crucial enzyme responsible for the redox homeostasis inside the cell. As a part of the antioxidant defense system, it plays a pivotal role in the dismutation of the superoxide radicals (O 2 - $$ {{\mathrm{O}}_2}^{-} $$ ) generated mainly by the oxidative phosphorylation, which would otherwise bring out the redox dysregulation, leading to higher reactive oxygen species (ROS) generation and, ultimately, cell transformation, and malignancy. Several studies have shown the involvement of ROS in a wide range of human cancers. As SOD is the key enzyme in regulating ROS, any change, such as a transcriptional change, epigenetic remodeling, functional alteration, and so forth, either activates the proto-oncogenes or aberrant signaling cascades, which results in cancer. Interestingly, in some cases, SODs act as tumor promoters instead of suppressors. Furthermore, SODs have also been known to switch their role during tumor progression. In this review, we have tried to give a comprehensive account of SODs multifactorial role in various human cancers so that SODs-based therapeutic strategies could be made to thwart cancers.
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Anti-melanoma and antioxidant properties of the methanol extract from the leaves of Phragmenthera capitata (Spreng.) Balle and Globimetula braunii (Engl.) Van Tiegh. JOURNAL OF COMPLEMENTARY & INTEGRATIVE MEDICINE 2024; 21:88-100. [PMID: 37916849 DOI: 10.1515/jcim-2023-0225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 10/03/2023] [Indexed: 11/03/2023]
Abstract
OBJECTIVES Phragmenthera capitata (Spreng.) Balle and Globimetula braunii (Engler.) Van Tiegh are African mistletoe traditionally used in cancers treatment. Thus, the aim of the study was to assess the anti-melanoma potential of the methanol extract of Phragmenthera capitata (Spreng.) Balle (PCMe-OH) and Globimetula braunii (Engler.) (GBMe-OH) Van Tiegh. METHODS Antioxidant potential was evaluated using DPPH, FRAP and hydroxyl assays. Total flavonoid and phenolic contents was also determined. MTT assay was used to estimate the effects on cell viability using SK-MLE28 and B16-F10 cell lines. Colony formation and wound healing were also assessed. Fluorometry methods were used for qualitative analysis of apoptosis and estimate ROS production. Western blot analysis was used for protein expression. RESULTS Phragmenthera capitata (PCMe-OH) showed the highest antioxidant activity and possess the highest phenolic contents (1,490.80 ± 55 mgGAE/g extract) in comparison with G. braunii (GBMe-OH) and (1,071.40 ± 45 mgGAE/g extract). Flavonoid content was similar in both extracts (11.63 ± 5.51 mg CATE/g of extract and 12.46 ± 2.58 mg CATE/g of extract respectively). PC-MeOH showed the highest cytotoxicity effect (IC50 of 55.35 ± 1.17 μg/mL) and exhibited anti-migrative potential on B16-F10 cells. Furthermore, PC-MeOH at 55.35 and 110.7 μg/mL; promoted apoptosis-induced cell death in B16-F10 cells by increasing intracellular ROS levels and reducing Bcl-2 expression level at 110.7 μg/mL. Significant upregulation of P-PTEN expression was recorded with PC-MeOH at 110.7 μg/mL; inhibiting therefore PI3K/AKT/m-Tor signaling pathway. Moreover, at 55.37 μg/mL significant reduction of c-myc and cyclin D1 was observed; dysregulating the MAPK kinase signaling pathway and cell cycle progression. CONCLUSIONS Phragmenthera capitata may be developed into selective chemotherapy to fight against melanoma.
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Development of an all-solid-state air-cooled high-power blue diode laser for metal processing. OPTICS LETTERS 2024; 49:17-20. [PMID: 38134141 DOI: 10.1364/ol.502493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 11/08/2023] [Indexed: 12/24/2023]
Abstract
We present the design and development of an all-solid-state (fluid/refrigerant-free) 100 W scale blue-laser system and show its applications in precision copper works. We combine powerful laser-diode arrays with Peltier chips on a compact laser head to achieve stable thermal and optical performance. Good agreement between the thermal simulation of the 3D laser head and experiments validates stable thermal performance. The laser system emits 40-100 W continuous wave at λ = 452.2 ± 2.5 nm with 98% power stability and ∼24% wall-plug efficiency inside a portable enclosure. This is the first, to the best of our knowledge, all-solid-state air-cooled laser with a 100 W class output. We achieved kW/cm2 intensity level on an mm-size focus with this source and demonstrated cutting, bending, and soldering copper on a battery pack. Furthermore, the copper-solder joints have nanoscale adhesion without cracks. Additionally, we unveil that 0.5-4 kW/cm2 intensity laser annealing scan makes copper strips mechanically resilient to withstand extreme loading cycles without nanoscale cracks.
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Regioselective synthesis and in vitro cytotoxicity evaluation of 3-thiooxindole derivatives: Tubulin polymerization inhibition and apoptosis inducing studies. Bioorg Med Chem 2023; 90:117297. [PMID: 37343499 DOI: 10.1016/j.bmc.2023.117297] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 04/13/2023] [Accepted: 04/22/2023] [Indexed: 06/23/2023]
Abstract
Herein, regiospecific nucleophilic ring-opening of spiroaziridine oxindoles has been established to afford 3-substituted-thiooxindole derivatives as anticancer agents. Among the new series, compounds 7d and 9c exhibited promising cytotoxic activity toward HCT-116 cells with IC50 values of 6.73 ± 0.36 and 6.64 ± 0.95 µM, respectively. Further, AO/EB, DCFDA, and DAPI staining studies were executed to establish the underlying apoptosis mechanism which displayed significant nuclear and morphological alterations. JC-1 staining and annexin V binding assay inferred the loss of mitochondrial membrane potential in HCT-116 cancer cells. Cell cycle analysis showed the treatment of 9c against HCT-116 cells, arrested the cell cycle in G2-M phase. In addition, tubulin binding assay revealed that compound 9c exhibited tubulin polymerase inhibition with IC50 value of 9.73 ± 0.18 μM. This inhibition of tubulin polymerase was further supported by binding interactions of 9c with tubulin through docking studies on PDB ID: 3E22.
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Nanodiamonds enable femtosecond-processed ultrathin glass as a hybrid quantum sensor. Sci Rep 2023; 13:6286. [PMID: 37072395 PMCID: PMC10113221 DOI: 10.1038/s41598-023-30689-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 02/28/2023] [Indexed: 05/03/2023] Open
Abstract
The quantum properties of fluorescent nanodiamonds offer great promise for fabricating quantum-enabled devices for physical applications. However, the nanodiamonds need to be suitably combined with a substrate to exploit their properties. Here, we show that ultrathin and flexible glass (thickness 30 microns) can be functionalized by nanodiamonds and nano-shaped using intense femtosecond pulses to design cantilever-based nanomechanical hybrid quantum sensors. Thus fabricated ultrathin glass cantilevers show stable optical, electronic, and magnetic properties of nitrogen-vacancy centers, including well-defined fluorescence with zero-phonon lines and optically detected magnetic resonance (ODMR) near 2.87 GHz. We demonstrate several sensing applications of the fluorescent ultrathin glass cantilever by measuring acoustic pulses, external magnetic field using Zeeman splitting of the NV centers, or CW laser-induced heating by measuring thermal shifting of ODMR lines. This work demonstrates the suitability of the femtosecond-processed fluorescent ultrathin glass as a new versatile substrate for multifunctional quantum devices.
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Organocatalytic C-H Bond Functionalizations for the Synthesis of Heterocycles. CURRENT ORGANOCATALYSIS 2023. [DOI: 10.2174/2213337210666230213120833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Abstract:
Organocatalysis is an important and rapidly growing area for the synthesis of various organic molecules. Because of the inherent non-metal properties, mild reaction conditions, and broad functional group tolerance, the use of small organic compounds encoding and converting another organic component has developed into a remarkable process. C–H activation reactions, on the other hand, have already emerged as a powerful strategy for forming C–C and C–X (X= N, O, S) bonds. Combining organocatalysis and C-H bond functionalization is highly rational as two coexisting and rapidly growing research fields in modern synthetic chemistry, and the cooperative strength along this consistent has proven to be a successful way of making C-H bond functionalization much more feasible, reliable, and specific. At the same time, the synthesis of heterocyclic compounds is an important field in organic chemistry due to the vast application of heterocycles in pharmaceuticals, polymers, and material science. This mini-review describes the recent developments in the synthesis of heterocyclic compounds through the alliance of organocatalysis and C-H bond functionalizations.
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Use of Gold Nanoparticles in the Synthesis of Heterocyclic Compounds. LETT ORG CHEM 2022. [DOI: 10.2174/1570178619666220826115245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract:
Nanoparticles have been proven to be efficient catalysts for a variety of chemical reactions, with added advantages such as reuse of catalysts, increasing the scale of reactions employing continuous flow techniques, and simple separation of the reaction milieu, making them green, efficient, and lucrative choices. Over the last decade, gold nanoparticles (AuNPs) have appeared as promising and efficient catalysts in the field of sustainable organic synthesis. On the other hand, heterocycles are significant scaffolds in a variety of natural products and other biologically active molecules, as well as useful compounds for organic and material chemistry. Therefore, the progress of proficient techniques for the synthesis of heterocyclic compounds is always of major significance. This mini-review focuses on some of the most important AuNPs catalyzed heterocyclic compound synthesis processes. Wherever essential, the exclusivity of the approaches has been discussed by emphasizing the substrate diversity, selectivity, product yields, and mechanistic features.
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Synthesis of indolo/pyrroloazepinone-oxindoles as potential cytotoxic, DNA-intercalating and Topo I inhibitors. Bioorg Chem 2022; 122:105706. [DOI: 10.1016/j.bioorg.2022.105706] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 02/18/2022] [Accepted: 02/22/2022] [Indexed: 12/13/2022]
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Amelioration of experimentally induced inflammatory arthritis by intra-articular injection of visnagin. CURRENT RESEARCH IN PHARMACOLOGY AND DRUG DISCOVERY 2022; 3:100114. [PMID: 35992378 PMCID: PMC9389203 DOI: 10.1016/j.crphar.2022.100114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 06/04/2022] [Accepted: 06/16/2022] [Indexed: 11/18/2022] Open
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Dithiocarbamation of spiro-aziridine oxindoles: a facile access to C3-functionalised 3-thiooxindoles as apoptosis inducing agents. Org Biomol Chem 2021; 19:10622-10634. [PMID: 34870311 DOI: 10.1039/d1ob02102h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Herein, we report the first dithiocarbamation of spiro-aziridine oxindoles involving regiospecific ring-opening by using in situ generated nucleophilic dithiocarbamates as an instant source of sulfur. This approach afforded C3-functionalised-3-thiooxindoles in good to excellent yields with a wide substrate scope under catalyst-free and mild reaction conditions. These compounds were screened for their anticancer activity against a panel of human cancer cell lines, wherein compound 3u exhibited significant cytotoxic activity against human lung cancer cells with an IC50 value of 4.31 ± 1.88 μM. Phase contrast microscopy as well as different staining assays such as acridine orange/ethidium bromide (AO/EB), DAPI and DCFDA demonstrated the induction of apoptosis in A549 lung cancer cells after treatment with compound 3u. In addition, the clonogenic assay and migration assay demonstrated the ability of compound 3u to inhibit colony formation and cell migration, respectively, in A549 cells in a dose-dependent manner.
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Synthetic Methods for the Preparation of Conformationally Restricted Analogues of Nicotine. Molecules 2021; 26:7544. [PMID: 34946630 PMCID: PMC8706964 DOI: 10.3390/molecules26247544] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 11/22/2022] Open
Abstract
In the context of naturally occurring nitrogen heterocycles, nicotine is a chiral alkaloid present in tobacco plants, which can target and stimulate nicotinic acetylcholine receptors (nAChRs), a class of ligand-gated ion channels commonly located throughout the human brain. Due to its well-known toxicity for humans, there is considerable interest in the development of synthetic analogues; in particular, conformationally restricted analogues of nicotine have emerged as promising drug molecules for selective nAChR-targeting ligands. In the present mini-review, we will describe the synthesis of the conformationally restricted analogues of nicotine involving one or more catalytic processes. In particular, we will follow a systematic approach as a function of the heteroarene structure, considering: (a) 2,3-annulated tricyclic derivatives; (b) 3,4-annulated tricyclic derivatives; (c) tetracyclic derivatives; and (d) other polycyclic derivatives. For each of them we will also consider, when carried out, biological studies on their activity for specific nAChR subunits.
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Mesenchymal Stem Cell-Derived Exosomes as an Emerging Paradigm for Regenerative Therapy and Nano-Medicine: A Comprehensive Review. Life (Basel) 2021; 11:life11080784. [PMID: 34440528 PMCID: PMC8399916 DOI: 10.3390/life11080784] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 01/08/2023] Open
Abstract
Mesenchymal Stem Cells are potent therapeutic candidates in the field of regenerative medicine, owing to their immunomodulatory and differentiation potential. However, several complications come with their translational application like viability, duration, and degree of expansion, long-term storage, and high maintenance cost. Therefore, drawbacks of cell-based therapy can be overcome by a novel therapeutic modality emerging in translational research and application, i.e., exosomes. These small vesicles derived from mesenchymal stem cells are emerging as new avenues in the field of nano-medicine. These nano-vesicles have caught the attention of researchers with their potency as regenerative medicine both in nanotherapeutics and drug delivery systems. In this review, we discuss the current knowledge in the biology and handling of exosomes, with their limitations and future applications. Additionally, we highlight current perspectives that primarily focus on their effect on various diseases and their potential as a drug delivery vehicle.
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Spectroscopic investigation of hydrogen and triple-oxygen isotopes in atmospheric water vapor and precipitation during Indian monsoon season. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2021; 57:368-385. [PMID: 34080500 DOI: 10.1080/10256016.2021.1931169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 04/05/2021] [Indexed: 06/12/2023]
Abstract
Water vapor, the most important greenhouse gas in the atmosphere, has four natural stable isotopologues (H216O, H217O, H218O and HD16O), and their isotopic compositions can be used as hydrological tracers. But the underlying processes and pattern-dynamics of the isotopic compositions of atmospheric water vapor and precipitation in response to various meteorological conditions during monsoon season in a tropical hot and humid region is poorly understood. Here, we present results of H and triple-O-isotopes of water in precipitation and atmospheric water vapor during monsoon season exploiting high-resolution integrated cavity output spectroscopy technique. We observed a distinct temporal variation of the isotopic compositions of water at different phases of the monsoon. The diurnal patterns of the isotopic variations were influenced by the local meteorological factors such as temperature, relative humidity and amount of precipitation. We also investigated the monsoonal dynamics of the second-order isotopic parameters, so-called d-excess and 17O-excess along with the influence of local meteorological factors on isotopic variations to improve our understanding of the underlying isotopic fractionation processes. Consequently, our results provide a unique isotopic-fingerprint dataset of rainwater and atmospheric water vapor for a tropical region and thus shed a new light on hydrological and meteorological processes in the atmosphere.
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Optimal Protein Sequence Design Mitigates Mechanical Failure in Silk β-Sheet Nanocrystals. ACS Biomater Sci Eng 2021; 7:3156-3165. [PMID: 34151552 DOI: 10.1021/acsbiomaterials.1c00447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The excellent mechanical strength and toughness of spider silk are well characterized experimentally and understood atomistically using computational simulations. However, little attention has been focused on understanding whether the amino acid sequence of β-sheet nanocrystals, which is the key to rendering strength to silk fiber, is optimally chosen to mitigate molecular-scale failure mechanisms. To investigate this, we modeled β-sheet nanocrystals of various representative small/polar/hydrophobic amino acid repeats for determining the sequence motif having superior nanomechanical tensile strength and toughness. The constant velocity pulling of the central β-strand in the nanocrystal, using steered molecular dynamics, showed that homopolymers of small amino acid (alanine/alanine-glycine) sequence motifs, occurring in natural silk fibroin, have better nanomechanical properties than other modeled structures. Further, we analyzed the hydrogen bond (HB) and β-strand pull dynamics of modeled nanocrystals to understand the variation in their rupture mechanisms and explore sequence-dependent mitigating factors contributing to their superior mechanical properties. Surprisingly, the enhanced side-chain interactions in homopoly-polar/hydrophobic amino acid models are unable to augment backbone HB cooperativity to increase mechanical strength. Our analyses suggest that nanocrystals of pristine silk sequences most likely achieve superior mechanical strength by optimizing side-chain interaction, packing, and main-chain HB interactions. Thus, this study suggests that the nanocrystal β-sheet sequence plays a crucial role in determining the nanomechanical properties of silk, and the evolutionary process has optimized it in natural silk. This study provides insight into the molecular design principle of silk with implications in the genetically modified artificial synthesis of silk-like biomaterials.
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Abstract
:
Microwave chemistry is an emerging area of science mainly focusing on various applications
of microwave energy into chemical processes. Microwave irradiation has enormous potential to
provide controlled energy directly to the molecules of interest. On the other hand, homogeneous gold
catalysis has emerged in the last two decades or so as one of the most promising fields in organic and
organometallic chemistry. Its efficacy has been established many times for the construction of new C
– X (X = O, N, S, etc.) and C – C bonds under mild reaction conditions. Although a significant number
of reports have appeared in the literature regarding the homogeneous gold-catalyzed organic transformations
under microwave conditions, this is the first review article which is going to appear in the
literature. This mini-review is designed to give an interesting insight into various homogeneous goldcatalyzed
organic reactions under microwave irradiation for the synthesis of a library of electronically
and structurally diverse and biologically important organic molecules.
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Bioactivity of Marine Natural Product Xyloketals. LETT ORG CHEM 2020. [DOI: 10.2174/1570178617999200909114431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
:
Oceans can play a major role in supplying life-saving medicines in the world in future. Although considerable
progress has been made in finding new medicines from marine sources, large efforts are still necessary to examine such
molecules for clinical applications. Xyloketals are an important group of natural products with various powerful and prominent bioactivities such as inhibition of acetylcholine esterase, antioxidant activity, inhibition of L-calcium channels, radicalscavenging behavior, suppression of cell proliferation, reduction of neonatal hypoxic-ischemic brain injury, etc. This review
describes the isolation and structural characterization of all xyloketal natural products giving major emphasis on their bioactivity.
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Bioactive compounds from marine invertebrates as potent anticancer drugs: the possible pharmacophores modulating cell death pathways. Mol Biol Rep 2020; 47:7209-7228. [PMID: 32797349 DOI: 10.1007/s11033-020-05709-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 08/02/2020] [Indexed: 12/24/2022]
Abstract
Marine invertebrates are extremely diverse, largely productive, untapped oceanic resources with chemically unique bioactive lead compound contributing a wide range of screening for the discovery of anticancer compounds. The lead compounds have unfurled an extensive array of pharmacological properties owing to the presence of polyphenols, alkaloids, terpenoids and other secondary metabolites. The antioxidant, immunomodulatory and anti-tumor activities exhibited, are possibly regulated by the apoptosis induction, scavenging of ROS and modulation of cellular signaling pathways to defy the cellular deafness during carcinogenesis. Despite the enriched bioactive compounds, the marine invertebrates are largely unexplored as identification, screening, pre-clinical and clinical assessment of lead compounds and their synthetic analogs remain a major task to be solved. In the current review, we focus on the principle strategy and underlying mechanisms deployed by the bioactive anticancer compounds derived from marine invertebrates to combat cancer with special insight into the cell death mechanism.
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Gas-Phase Isotopic Fractionation Study of Singly and Doubly Deuterated Isotopologues of Water in the H-D Exchange Reaction by Cavity Ring-Down Spectroscopy. J Phys Chem A 2020; 124:1104-1111. [PMID: 31961682 DOI: 10.1021/acs.jpca.9b11401] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The underlying mechanisms of the triple-oxygen (16O, 17O, and 18O) isotopic content of deuterated (D) isotopologues of water in H-D exchange reactions in the gas phase remain elusive. Herein, we have demonstrated a high-resolution gas-phase spectral analysis of doubly (D2O) and singly (HDO) deuterated isotopologues of water in the region around 7.8 μm using quantum cascade laser-based cavity ring-down spectroscopy. Isotopic fractionations among doubly and singly deuterated species of water, D216O, HD16O, HD17O, and HD18O, in the gas phase were carried out by probing the fundamental and hot band transitions in the ν2 (bending) mode of D2O and the fundamental ν2 transitions for the other water isotopes. We subsequently investigated the fractionations of different D-enriched water isotopologues for the H-D exchange reaction using various mixtures of D2O in H2O. We explored the potential role of triple-oxygen isotopic contents through enrichments and depletions of HD16O, HD17O, and HD18O, involved in the H-D reaction. Our first clear, direct, and quantitative experimental evidence reveals a new picture of gas-phase isotopic fractionation chemistry in a mixture of light and heavy water (H2O-D2O).
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Joy and Challenges of Alkynylation of Arenes and Heteroarenes through Double C−H Functionalizations. ASIAN J ORG CHEM 2020. [DOI: 10.1002/ajoc.201900733] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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VASCULAR STENOSIS DETECTION USING TEMPORAL-SPECTRAL DIFFERENCES IN CORRELATED ACOUSTIC MEASUREMENTS. ... IEEE SIGNAL PROCESSING IN MEDICINE AND BIOLOGY SYMPOSIUM (SPMB). IEEE SIGNAL PROCESSING IN MEDICINE AND BIOLOGY SYMPOSIUM 2019; 2019. [PMID: 33869739 DOI: 10.1109/spmb47826.2019.9037853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Central venous stenosis is often undiagnosed in patients with hemodialysis vascular access, partly due to imaging difficulties. Noninvasive, point-of-care detection could rely on detecting regions of turbulent blood flow caused by blood velocity changes. Here we present flexible microphone arrays for time-correlated measures of blood flow sounds and a new signal processing approach to calculate time correlation between spectral features. Continuous wavelet transform was used to produce an auditory spectral flux analytic signal, which was thresholded to identify systolic start and end phases. Microphone arrays were tested on pulsatile flow phantoms with blood flow rates of 850-1,200 mL/min and simulated stenosis from 10-85%. Measured results showed an inversion in the time onset of systolic spectral content for sites proximal and distal to stenosis for hemodynamically significant stenoses (+22 ms for stenosis<50% and -20 to -38 ms for stenosis>50%). Equivalent blood velocity increases were calculated as 142-155 cm/s in stenotic phantoms, which are within the physiologic range as measured by ultrasound.
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Stereospecific Synthesis of Poly(methylene-E-vinylene) by Ring Opening Metathesis Polymerization of Substituted Cyclopropene Using Grubbs Catalysts. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b01956] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Total Synthesis of Xyloketals and Related Natural Product Alboatrin: Strategies and Tactics. ChemistrySelect 2019. [DOI: 10.1002/slct.201900779] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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31
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Total synthesis of Bruguierols: strategies and tactics. ARKIVOC 2019. [DOI: 10.24820/ark.5550190.p010.966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Ecotoxic impact assessment of graphene oxide on lipid peroxidation at mitochondrial level and redox modulation in fresh water fish Anabas testudineus. CHEMOSPHERE 2019; 224:796-804. [PMID: 30851531 DOI: 10.1016/j.chemosphere.2019.02.156] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 02/22/2019] [Accepted: 02/23/2019] [Indexed: 06/09/2023]
Abstract
Rapidly expanding nanoparticle industries are predicted to have turnover of ∼$173.95 billion by 2025, indicating an urgency to study their comprehensive toxicological impact(s). Toxic effects of Graphene Oxide (GO) on oxidative stress physiology especially at mitochondrial level and redox modulation in fish in general and in climbing perch Anabas testudineus is absent. Therefore, we have investigated the toxic impacts of sub lethal doses of GO on selected oxidative stress physiology markers, protein and nucleic acid content along with haematological parameters in A. testudineus. Discriminant function and correlation analyses suggest that GO had toxic effects on the fish, as revealed from the studied parameters. Liver and gill tissues had shown strong response to GO than muscle. Augmented gradual accumulation of cellular lipid peroxides, specifically in mitochondria, was noticed. Activity of superoxide dismutase, catalase, and glutathione-S-transferase was augmented in contrast to the lowered level of the reduced glutathione titre. Alleviated total red blood corpuscle count and haemoglobin titre was parallel with an augmentation of white blood corpuscle count under GO administration. The protein level was also alleviated gradually in liver with clear changes in tissue specific nucleic acid levels, which was reduced under GO treatment. Results of the present study indicate that GO induces oxidative stress in cell and mitochondria in fish. Therefore, very careful future practices of use of GO directly, or as cargo in environmental monitoring processes in aquatic models in vitro in general and Pisces model in particular are suggested.
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Time-resolved nano-Newton force spectroscopy in air and vacuum using a load cell of ultra micro-balance. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:043117. [PMID: 31043051 DOI: 10.1063/1.5086260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 03/25/2019] [Indexed: 06/09/2023]
Abstract
We demonstrate a simple and versatile nanomechanical force measuring setup with 1 nN precision in air and vacuum using a load cell of an ultra-microbalance. We validate stability, precision, and linearity of the load cell with simple tests. The setup is customized to measure stress-strain response of biomaterials (silk, leaf, and flower) and capillary force in fluids. We isolated an optical pull force induced by a Watt-level laser reflected from a mirror/solid surface in air, in addition to optical push force. Furthermore, we add an interferometric probe to directly measure nanoscale deflection of cantilever of the load cell in real-time, thus bypassing its conventional electromagnetic readout, to improve speed and precision of the instrument. We demonstrate nanomechanical force measurement in high vacuum with the same precision and employ radiation pressure to calibrate the load cell for various precision measurements.
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Stenosis Characterization and Identification for Dialysis Vascular Access. ... IEEE SIGNAL PROCESSING IN MEDICINE AND BIOLOGY SYMPOSIUM (SPMB). IEEE SIGNAL PROCESSING IN MEDICINE AND BIOLOGY SYMPOSIUM 2018; 2018:10.1109/SPMB.2018.8615597. [PMID: 31788552 PMCID: PMC6885304 DOI: 10.1109/spmb.2018.8615597] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vascular access dysfunction is the leading cause of hospitalization for hemodialysis patients and accounts for the most medical costs in this patient population. Vascular access flow is commonly hindered by blood vessel narrowing (stenosis). Current screening methods involving imaging to detect stenosis are too costly for routine use at the point of care. Noninvasive, real-time screening of patients at risk of vascular access dysfunction could potentially identify high-risk patients and reduce the likelihood of emergency surgical interventions. Bruits (sounds produced by turbulent blood flow near stenoses) can be interpreted by skilled clinical staff using conventional stethoscopes. To improve the sensitivity of detection, digital analysis of blood flow sounds (phonoangiograms or PAGs) is a promising approach for classifying vascular access stenosis using non-invasive auditory recordings. Here, we demonstrate auditory and spectral features of PAGs which estimate both the location and degree of stenosis (DOS). Auditory recordings from nine stenosis phantoms with variable DOS and hemodynamic flow rate were obtained using a digital recording stethoscope and analyzed to extract classification features. Autoregressive modeling and discrete wavelet transforms were used for multiresolution signal decomposition to produce 14 distinct features, most of which were linearly correlated with DOS. Our initial results suggest that the widely-used auditory spectral centroid is a simple way to calculate features which can estimate both the location and severity of vascular access stenosis.
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SKIN-COUPLED PVDF MICROPHONES FOR NONINVASIVE VASCULAR BLOOD SOUND MONITORING. ... IEEE SIGNAL PROCESSING IN MEDICINE AND BIOLOGY SYMPOSIUM (SPMB). IEEE SIGNAL PROCESSING IN MEDICINE AND BIOLOGY SYMPOSIUM 2018; 2018. [PMID: 31742227 DOI: 10.1109/spmb.2018.8615606] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vascular access is the "Achilles Heel" of hemodialysis, as maintaining high flow characteristics (access patency) is critical to achieving efficient dialysis treatment. Thus, monitoring of vascular access is essential for maintaining long-term dialysis success. Blood sounds change in the presence of stenosis and can be analyzed digitally as phonoangiograms (PAGs) to determine changes in hemodynamic flow. We propose a multi-channel PAG recording sensor suitable for rapid, non-invasive vascular access monitoring. Here we present the initial design and characterization of sensors appropriate for recording PAGs from the skin surface. An optimized sensor size and backing material was selected to improve sensitivity and to provide a neutral frequency response. The sensor performance was finally compared with a conventional stethoscope on a controlled blood flow stenosis benchtop phantom.
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An illustration of human sperm morphology and their functional ability among different group of subfertile males. Andrology 2018; 6:680-689. [PMID: 29959832 DOI: 10.1111/andr.12500] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 02/22/2018] [Accepted: 04/08/2018] [Indexed: 11/30/2022]
Abstract
Condensed sperm chromatin is a prerequisite for natural fertilization. Some reports suggested the prevalence of chromatin condensation defects in teratozoospermia cases with head anomalies; conversely, earlier studies exemplified its occurrence in morphologically normal spermatozoa too. The aim of this study was to compare the condensation defects in correlation with head anomalies among different groups of subfertile males and its impact on the rate of fertilization in assisted reproduction procedures. Ultrastructure analysis of spermatozoa through scanning electron microscopy and atomic force microscopy could facilitate an in-depth evaluation of sperm morphology. Nuclear condensation defects (%) in spermatozoa were analyzed in 666 subjects, and its effect on the rate of fertilization was analyzed in 116 IVF and 90 intracytoplasmic sperm injection cases. There was no correlation of condensation defects with head anomalies (%). Student's t-test showed no significant changes in mean values of condensation defects in abnormal semen samples in comparison with the normal group. Condensation defects were observed in normal spermatozoa too, which was negatively associated with the rate of fertilization in IVF (p < 0.01), but intracytoplasmic sperm injection outcome remained unaffected. Ultrastructure study revealed sperm morphological features in height, amplitude, and three-dimensional views in atomic force microscopy images presenting surface topography, roughness property of head, and compact arrangement of mitochondria over axoneme with height profile at nanoscale. In pathological forms, surface roughness and nuclear thickness were marked higher than the normal spermatozoa. Thus, percentage of normal spermatozoa with condensation defects could be a predictive factor for the rate of fertilization in IVF. From diverse shapes of nucleus in AFM imaging, it could be predicted that defective nuclear shaping might be impeding the activity of some proteins/ biological motors, those regulate the proper Golgi spreading over peri-nuclear theca.
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Synthesis and characterization of solid-phase super acid catalysts and their application for isomerization of n-alkanes. CHEM ENG COMMUN 2017. [DOI: 10.1080/00986445.2017.1365059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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40
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Assessment of Antibacterial Activity of Smaller Chain Tripeptides and Tetrapeptides. Drug Res (Stuttg) 2014; 64:623-8. [DOI: 10.1055/s-0034-1367037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Left pulmonary artery agenesis with pulmonary hypoplasia in an elderly patient: a rare case report. BANGLADESH JOURNAL OF MEDICAL SCIENCE 2013. [DOI: 10.3329/bjms.v12i4.13689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Proximal interruption of the unilateral pulmonary artery is a rare congenital anomaly, which is often associated with other cardiovascular abnormalities. It is usually diagnosed in children but rarely discovered in adulthood as an isolated phenomenon, occurring more frequently on the right side and is often associated with a contralateral aortic arch. We are presenting a rare case of a sixty year old male who was diagnosed with left lung hypoplasia due to proximal interruption of left pulmonary artery with left sided aortic arch without any associated cardiovascular anomalies. DOI: http://dx.doi.org/10.3329/bjms.v12i4.13689 Bangladesh Journal of Medical Science Vol. 12 No. 04 October 13 Page 462-466
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O09.3 A Successful Model in Reaching Out Mobile Population to Control the Spread of STI/HIV/AIDS: Experience from Link Worker Scheme Implemented in 200 Villages Mostly Inhibited by Mobile Population in West Bengal, India. Br J Vener Dis 2013. [DOI: 10.1136/sextrans-2013-051184.0133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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43
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O09.1 Voices of HIV Infected Children and Their Families. Br J Vener Dis 2013. [DOI: 10.1136/sextrans-2013-051184.0131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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P4.127 Red Ribbon Clubs (RRCs): A Low Cost Community Led Structural Intervention to Reach Out the Youth to Initiate Dialogue on Sex & Sexuality & to Control the Spread STI/HIV and Other Communicable Diseases in Rural Setting. Br J Vener Dis 2013. [DOI: 10.1136/sextrans-2013-051184.1024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Gold and Palladium Combined for the Sonogashira Coupling of Aryl and Heteroaryl Halides. SYNTHESIS-STUTTGART 2013. [DOI: 10.1055/s-0033-1338474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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46
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Gold-Catalyzed Benzannulation of Electronically Rich/Rich and Deficient/Deficient Oxoalkynes with Alkynes. SYNTHESIS-STUTTGART 2013. [DOI: 10.1055/s-0032-1318454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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47
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Gold catalysis: regio- and stereoselective total synthesis of xyloketals D and G and the related natural product alboatrin. J Org Chem 2013; 78:2413-21. [PMID: 23428314 DOI: 10.1021/jo302545n] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A new and efficient one-pot desilylation-gold-catalyzed cycloisomerization of alkynes containing a silyl-protected phenolic -OH and a free alcoholic -OH unit leads selectively to the formation of tetrahydrofuranobenzopyran ring system. This approach has been used for the regio- and stereoselective synthesis of xyloketal D, xyloketal G, and the related natural product alboatrin.
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Gold and Palladium Combined for the Sonogashira Coupling of Aryl and Heteroaryl Halides. SYNTHESIS-STUTTGART 2013. [DOI: 10.1055/s-0032-1318119] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Morphology and dielectric relaxation spectroscopy of ternary polymer blends of polyamide6, polypropylene, and acrylonitrile butadiene styrene co-polymer: Influence of compatibilizer and multiwall carbon nanotubes. J Appl Polym Sci 2012. [DOI: 10.1002/app.38074] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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50
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PD30. Identification of novel somatic mutations and structural variations in tongue cancer, matched leukoplakia and normal tissue by genome sequencing. Oral Oncol 2011. [DOI: 10.1016/j.oraloncology.2011.06.060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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