339 research outputs found

    Synthesis and Characterization of New Polyimide Contain Heterocyclic

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    Novel heterocyclic polyimide 5(a,b) have been synthesized based on polyacrylic backbone. The synthetic route start with nucleophilic substitution of 2-amino, or 4-amino, pyridine 1(a,b) to the polyacryloyl chloride afforded poly substituted amide 2(a,b). Another nucleophilic substitution were carried with adipoyl chloride to form polyimide chloride 3(a,b). Treatment of 3(a,b) with hydrazine hydrate afforded acid hydrazide polyimide 4(a,b), which upon cyclocondensation with carbon disulfide gave the target heterocyclic polyimide. The synthesized compounds were identified by spectroscopic methods: FT-IR, 1H-NMR and 13C-NMR

    Synthesis, Characterization and Antibacterial Activity of Cefalexin Dervatives

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    New series of Schiff bases 2(a-j) and corresponding beta-lactam derivatives 3(a-j) were synthesized from cefalexin (1) as starting material. The compound (1) was reacted with different aldehydes and ketones to give Schiff bases derivatives 2(a-j). The synthesized Schiff bases were cyclized by chloroacetyl chloride in the presence of triethylamine to form beta-lactam derivatives 3(a-j). The compounds were characterized by deremination melting point, FT-IR and 1H NMR. The beta-lactam derivatives were screened in vitro antibacterial against some bacterial specie

    Design of Double Notch Band Half-Elliptical Shape Reconfigurable Antenna for UWB Applications

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    A compact ultra-wideband (UWB) reconfigurable antenna with dual band-notched properties is presented in this paper. The dual notch band half – elliptical reconfigurable antenna is fed by (50 Ω) microstrip feed lines and it is printed above an FR-4 substrates (32 × 32.6) mm2 dimensions. This dual band notched characteristic is accomplished by embedding two crossing U-shaped slot in the half-elliptical radiating patch of the proposed reconfigurable antenna. The modeling procedure and performance evaluation of the presented antenna was achieved by using the electromagnetic simulator software, (CST) Computer Simulation Technology. The measured bandwidth of the presented antenna for (VSWR 2) in 3.5 GHz and 5.2 GHz. The presented antenna is appropriate for UWB applications with another benefits of reduces the interference effect with the wireless local area network (WLAN) systems that operating in 5.15–5.35 GHz band (IEEE 802.11a), as well as reducing the interference effect with the Worldwide Interoperability for Microwave Access (WiMAX) application, which operates in 3.5 GHz band (IEEE 802.16e). The parameters that affect the efficiency of the antenna as regards to its frequency domain and radiation pattern qualities are studied

    Synthesis of N-benzothiazole derivative imide on polymeric chain, have possible biological activity

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    In this reserch Some new substituted and unsubstituted poly imides compounds. were synthesized by reaction of acrylol chloride with different amides (aliphatic and aromatic) in a suitable solvent in the presence amount triethyl amine (Et3N) with heating. The Structure confirmation of all polymers were confirmed using FT-IR,1H-NMR,13C-NMR and UV spectroscopy. Thermal analysis (TG) for some polymers showed their thermal stabilities. Other physical properties including softening points, melting point and solubility of the polymers were also measure

    The 'Ins and Outs' of Early Preclinical Models for Brain Tumor Research: Are They Valuable and Have We Been Doing It Wrong?

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    In this perspective, we congratulate the international efforts to highlight critical challenges in brain tumor research through a recent Consensus Statement. We also illustrate the importance of developing more accurate and clinically relevant early translational in vitro brain tumor models-a perspective given limited emphasis in the Consensus Statement, despite in vitro models being widely used to prioritize candidate therapeutic strategies prior to in vivo studies and subsequent clinical trials. We argue that successful translation of effective novel treatments into the clinic will require investment into the development of more predictive early pre-clinical models. It is in the interest of researchers, clinicians, and ultimately, patients that the most promising therapeutic candidates are identified and translated toward use in the clinic. Highlighting the value of early pre-clinical brain tumor models and debating how such models can be improved is of the utmost importance to the neuro-oncology research community and cancer research more broadly

    Tumour treating fields therapy for glioblastoma : current advances and future directions

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    Glioblastoma multiforme (GBM) is the most common primary brain tumour in adults and continues to portend poor survival, despite multimodal treatment using surgery and chemoradiotherapy. The addition of tumour-treating fields (TTFields)—an approach in which alternating electrical fields exert biophysical force on charged and polarisable molecules known as dipoles—to standard therapy, has been shown to extend survival for patients with newly diagnosed GBM, recurrent GBM and mesothelioma, leading to the clinical approval of this approach by the FDA. TTFields represent a non-invasive anticancer modality consisting of low-intensity (1–3 V/cm), intermediate-frequency (100–300 kHz), alternating electric fields delivered via cutaneous transducer arrays configured to provide optimal tumour-site coverage. Although TTFields were initially demonstrated to inhibit cancer cell proliferation by interfering with mitotic apparatus, it is becoming increasingly clear that TTFields show a broad mechanism of action by disrupting a multitude of biological processes, including DNA repair, cell permeability and immunological responses, to elicit therapeutic effects. This review describes advances in our current understanding of the mechanisms by which TTFields mediate anticancer effects. Additionally, we summarise the landscape of TTFields clinical trials across various cancers and consider how emerging preclinical data might inform future clinical applications for TTFields

    Chiral tartaric acid improves fracture toughness of bioactive brushite-collagen bone cements

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    Brushite cements are promising bone regeneration materials with limited biological and mechanical properties. Here, we engineer a mechanically improved brushite-collagen type I cement with enhanced biological properties by use of chiral chemistry; D- and L-tartaric acid were used to limit crystal growth and increase the mechanical properties of brushite-collagen cements. The impact of the chiral molecules on the cements was examined with FTIR, XRD and SEM. A 3-point bend test was utilised to study the fracture toughness and cell attachment and morphology studies to demonstrate biocompatibility. XRD and SEM analyses showed that L- but not D- tartaric acid, significantly restrained brushite crystal growth by binding to the {010} plane of the mineral, increased brushite crystal packing and the collagen-mineral interaction area. L-tartaric acid significantly improved fracture toughness compared to traditional brushite by 30 %. Collagen significantly enhanced cell morphology and focal adhesion expression on brushite cements

    Artificial intelligence in cancer imaging: Clinical challenges and applications

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    Judgement, as one of the core tenets of medicine, relies upon the integration of multilayered data with nuanced decision making. Cancer offers a unique context for medical decisions given not only its variegated forms with evolution of disease but also the need to take into account the individual condition of patients, their ability to receive treatment, and their responses to treatment. Challenges remain in the accurate detection, characterization, and monitoring of cancers despite improved technologies. Radiographic assessment of disease most commonly relies upon visual evaluations, the interpretations of which may be augmented by advanced computational analyses. In particular, artificial intelligence (AI) promises to make great strides in the qualitative interpretation of cancer imaging by expert clinicians, including volumetric delineation of tumors over time, extrapolation of the tumor genotype and biological course from its radiographic phenotype, prediction of clinical outcome, and assessment of the impact of disease and treatment on adjacent organs. AI may automate processes in the initial interpretation of images and shift the clinical workflow of radiographic detection, management decisions on whether or not to administer an intervention, and subsequent observation to a yet to be envisioned paradigm. Here, the authors review the current state of AI as applied to medical imaging of cancer and describe advances in 4 tumor types (lung, brain, breast, and prostate) to illustrate how common clinical problems are being addressed. Although most studies evaluating AI applications in oncology to date have not been vigorously validated for reproducibility and generalizability, the results do highlight increasingly concerted efforts in pushing AI technology to clinical use and to impact future directions in cancer care
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