Adsorption separation of heavier isotope gases in subnanometer carbon pores

AbstractIsotopes of heavier gases including carbon (13C/14C), nitrogen (13N), and oxygen (18O) are highly important because they can be substituted for naturally occurring atoms without significantly perturbing the biochemical properties of the radiolabelled parent molecules. These labelled molecules are employed in clinical radiopharmaceuticals, in studies of brain disease and as imaging probes for advanced medical imaging techniques such as positron-emission tomography (PET). Established distillation-based isotope gas separation methods have a separation factor (S) below 1.05 and incur very high operating costs due to high energy consumption and long processing times, highlighting the need for new separation technologies. Here, we show a rapid and highly selective adsorption-based separation of 18O2 from 16O2 with S above 60 using nanoporous adsorbents operating near the boiling point of methane (112 K), which is accessible through cryogenic liquefied-natural-gas technology. A collective-nuclear-quantum effect difference between the ordered 18O2 and 16O2 molecular assemblies confined in subnanometer pores can explain the observed equilibrium separation and is applicable to other isotopic gases.

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Molecular Imaging Probes Based on Matrix Metalloproteinase Inhibitors (MMPIs)

Molecules ◽

10.3390/molecules24162982 ◽

2019 ◽

Vol 24 (16) ◽

pp. 2982 ◽

Cited By ~ 4

Author(s):

Rangasamy ◽

Geronimo ◽

Ortín ◽

Coderch ◽

Zapico ◽

...

Keyword(s):

Single Photon ◽

Imaging Techniques ◽

Photon Emission ◽

Biological Evaluation ◽

Human Diseases ◽

Emission Computed Tomography ◽

Specific Subset ◽

Positron Emission ◽

Molecular Imaging Probes ◽

Imaging Probes

Matrix metalloproteinases (MMPs) are a family of zinc- and calcium-dependent endopeptidases which are secreted or anchored in the cell membrane and are capable of degrading the multiple components of the extracellular matrix (ECM). MMPs are frequently overexpressed or highly activated in numerous human diseases. Owing to the important role of MMPs in human diseases, many MMP inhibitors (MMPIs) have been developed as novel therapeutics, and some of them have entered clinical trials. However, so far, only one MMPI (doxycycline) has been approved by the FDA. Therefore, the evaluation of the activity of a specific subset of MMPs in human diseases using clinically relevant imaging techniques would be a powerful tool for the early diagnosis and assessment of the efficacy of therapy. In recent years, numerous MMPIs labeled imaging agents have emerged. This article begins by providing an overview of the MMP subfamily and its structure and function. The latest advances in the design of subtype selective MMPIs and their biological evaluation are then summarized. Subsequently, the potential use of MMPI-labeled diagnostic agents in clinical imaging techniques are discussed, including positron emission tomography (PET), single-photon emission computed tomography (SPECT) and optical imaging (OI). Finally, this article concludes with future perspectives and clinical utility.

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Peptide Based Imaging Agents for HER2 Imaging in Oncology

Molecular Imaging ◽

10.1177/1536012120960258 ◽

2020 ◽

Vol 19 ◽

pp. 153601212096025 ◽

Cited By ~ 1

Author(s):

Maxwell Ducharme ◽

Suzanne E. Lapi

Keyword(s):

Breast Cancer ◽

Pet Imaging ◽

Imaging Techniques ◽

Treatment Options ◽

Growth Factor Receptor ◽

Her2 Status ◽

Cancer Type ◽

Her2 Positive ◽

Positron Emission ◽

Imaging Probes

Breast cancer continues to be the most lethal cancer type in women and one of the most diagnosed. Understanding Breast cancer receptor status is one of the most vital processes for determining treatment options. One type of breast cancer, human epidermal growth factor receptor 2 (HER2) positive, has approved receptor-based therapies including trastuzumab and pertuzumab that can significantly increase the likelihood of survival. Current methods to determine HER2 status include biopsies with immunohistochemical staining and/or fluorescence in situ hybridization. However, positron emission tomography (PET) imaging techniques using 89Zr-trastuzumab or 89Zr-pertuzumab are currently in clinical trials for a non-invasive, full body diagnostic approach. Although the antibodies have strong specificity to the HER2 positive lesions, challenges involving long post-injection time for imaging due to the blood circulation of the antibodies and matching of long-live isotopes leading to increased dose to the patient leave opportunities for alternative PET imaging probes. Peptides have been shown to allow for shorter injection-to-imaging time and can be used with shorter lived isotopes. HER2 specific peptides under development will help improve the diagnosis and potentially therapy options for HER2 positive breast cancer. Peptides showing specificity for HER2 could start widespread development of molecular imaging techniques for HER2 positive cancers.

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PET Imaging of Adenosine Receptors in Diseases

Current Topics in Medicinal Chemistry ◽

10.2174/1568026619666190708163407 ◽

2019 ◽

Vol 19 (16) ◽

pp. 1445-1463 ◽

Cited By ~ 3

Author(s):

Jindian Li ◽

Xingfang Hong ◽

Guoquan Li ◽

Peter S. Conti ◽

Xianzhong Zhang ◽

...

Keyword(s):

Pet Imaging ◽

Adenosine Receptors ◽

Neurological Diseases ◽

G Protein Coupled Receptors ◽

Extracellular Adenosine ◽

Positron Emission ◽

Imaging Probes ◽

Pet Probes ◽

Cancer And Inflammation ◽

G Protein Coupled

Adenosine receptors (ARs) are a class of purinergic G-protein-coupled receptors (GPCRs). Extracellular adenosine is a pivotal regulation molecule that adjusts physiological function through the interaction with four ARs: A1R, A2AR, A2BR, and A3R. Alterations of ARs function and expression have been studied in neurological diseases (epilepsy, Alzheimer’s disease, and Parkinson’s disease), cardiovascular diseases, cancer, and inflammation and autoimmune diseases. A series of Positron Emission Tomography (PET) probes for imaging ARs have been developed. The PET imaging probes have provided valuable information for diagnosis and therapy of diseases related to alterations of ARs expression. This review presents a concise overview of various ARs-targeted radioligands for PET imaging in diseases. The most recent advances in PET imaging studies by using ARs-targeted probes are briefly summarized.

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A Novel Secure and Robust encryption scheme for medical images

Current Medical Imaging Formerly Current Medical Imaging Reviews ◽

10.2174/1573405616666200425215702 ◽

2020 ◽

Vol 16 ◽

Author(s):

Siyamol Chirakkarottu ◽

Sheena Mathew

Keyword(s):

Medical Images ◽

Technological Development ◽

Imaging Techniques ◽

Chaotic Map ◽

Two Phase ◽

Positron Emission ◽

Medical Diagnostic ◽

Wireless Medium ◽

Health Care Applications ◽

Magnetic Resonance Imaging Mri

Background: Medical imaging encloses different imaging techniques and processes to image the human body for medical diagnostic and treatment purposes. Hence it plays an important role to improve public health. The technological development in biomedical imaging specifically in X-ray, Computed Tomography (CT), nuclear ultrasound including Positron Emission Tomography (PET), optical and Magnetic Resonance Imaging (MRI) can provide valuable information unique to a person. Objective: In health care applications, the images are needed to be exchanged mostly over wireless medium. The diagnostic images with confidential information of a patient need to be protected from unauthorized access during transmission. In this paper, a novel encryption method is proposed to improve the security and integrity of medical images. Methods: Chaotic map along with DNA cryptography is used for encryption. The proposed method describes a two phase encryption of medical images. Results: Performance of the proposed method is also tested by various analysis metrics. Robustness of the method against different noises and attacks is analyzed. Conclusion: The results show that the method is efficient and well suitable to medical images.

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Recent Progress in the Molecular Imaging of Nonalcoholic Fatty Liver Disease

International Journal of Molecular Sciences ◽

10.3390/ijms22147348 ◽

2021 ◽

Vol 22 (14) ◽

pp. 7348

Author(s):

Olivia Wegrzyniak ◽

Maria Rosestedt ◽

Olof Eriksson

Keyword(s):

Liver Disease ◽

Molecular Imaging ◽

Fatty Liver ◽

Nonalcoholic Fatty Liver Disease ◽

Fatty Liver Disease ◽

Imaging Techniques ◽

Current Status ◽

Nonalcoholic Fatty Liver ◽

Positron Emission ◽

Activated Fibroblasts

Pathological fibrosis of the liver is a landmark feature in chronic liver diseases, including nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). Diagnosis and assessment of progress or treatment efficacy today requires biopsy of the liver, which is a challenge in, e.g., longitudinal interventional studies. Molecular imaging techniques such as positron emission tomography (PET) have the potential to enable minimally invasive assessment of liver fibrosis. This review will summarize and discuss the current status of the development of innovative imaging markers for processes relevant for fibrogenesis in liver, e.g., certain immune cells, activated fibroblasts, and collagen depositions.

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In Vivo Imaging of Biodegradable Implants and Related Tissue Biomarkers

Polymers ◽

10.3390/polym13142348 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2348

Author(s):

Leon Riehakainen ◽

Chiara Cavallini ◽

Paolo Armanetti ◽

Daniele Panetta ◽

Davide Caramella ◽

...

Keyword(s):

Imaging Modality ◽

Imaging Techniques ◽

Special Focus ◽

Tissue Remodelling ◽

Biodegradable Implant ◽

Advantages And Disadvantages ◽

Non Invasive ◽

Positron Emission ◽

Longitudinal Imaging

Non-invasive longitudinal imaging of osseointegration of bone implants is essential to ensure a comprehensive, physical and biochemical understanding of the processes related to a successful implant integration and its long-term clinical outcome. This study critically reviews the present imaging techniques that may play a role to assess the initial stability, bone quality and quantity, associated tissue remodelling dependent on implanted material, implantation site (surrounding tissues and placement depth), and biomarkers that may be targeted. An updated list of biodegradable implant materials that have been reported in the literature, from metal, polymer and ceramic categories, is provided with reference to the use of specific imaging modalities (computed tomography, positron emission tomography, ultrasound, photoacoustic and magnetic resonance imaging) suitable for longitudinal and non-invasive imaging in humans. The advantages and disadvantages of the single imaging modality are discussed with a special focus on preclinical imaging for biodegradable implant research. Indeed, the investigation of a new implant commonly requires histological examination, which is invasive and does not allow longitudinal studies, thus requiring a large number of animals for preclinical testing. For this reason, an update of the multimodal and multi-parametric imaging capabilities will be here presented with a specific focus on modern biomaterial research.

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The Clinical Value of PET with Amino Acid Tracers for Gliomas WHO Grade II

International Journal of Molecular Imaging ◽

10.1155/2011/372509 ◽

2011 ◽

Vol 2011 ◽

pp. 1-11 ◽

Cited By ~ 30

Author(s):

Anja Smits ◽

Brigitta G. Baumert

Keyword(s):

Amino Acid ◽

Hot Spot ◽

Imaging Techniques ◽

Biological Behavior ◽

Optimal Timing ◽

Low Grade ◽

Clinical Value ◽

Who Grade ◽

Positron Emission ◽

Therapeutic Procedures

The clinical management of adults with low-grade gliomas (LGGs) remains a challenge. There is no curative treatment, and management of individual patients is a matter of deciding optimal timing as well as right treatment modality. In addition to conventional imaging techniques, positron emission tomography (PET) with amino acid tracers can facilitate diagnostic and therapeutic procedures. In this paper, the clinical applications of PET with amino acid tracers 11C-methyl-L-methionine (MET) and 18F-fluoro-ethyl-L-tyrosine (FET) for patients with LGG are summarized. We also discuss the value of PET for the long-term followup of this patient group. Monitoring metabolic activity by PET in individual patients during course of disease will provide insight in the biological behavior and evolution of these tumors. As such, spatial changes in tumor activity over time, including shifts of hot-spot regions within the tumor, may reflect intratumoral heterogeneity and correlate to clinical parameters.

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News about the Role of Fluid and Imaging Biomarkers in Neurodegenerative Diseases

Biomedicines ◽

10.3390/biomedicines9030252 ◽

2021 ◽

Vol 9 (3) ◽

pp. 252

Author(s):

Jacopo Meldolesi

Keyword(s):

Neurodegenerative Diseases ◽

Imaging Techniques ◽

Imaging Biomarkers ◽

Positron Emission ◽

Specific Proteins ◽

Great Relevance ◽

The Brain ◽

Positive Point

Biomarkers are molecules that are variable in their origin, nature, and mechanism of action; they are of great relevance in biology and also in medicine because of their specific connection with a single or several diseases. Biomarkers are of two types, which in some cases are operative with each other. Fluid biomarkers, started around 2000, are generated in fluid from specific proteins/peptides and miRNAs accumulated within two extracellular fluids, either the central spinal fluid or blood plasma. The switch of these proteins/peptides and miRNAs, from free to segregated within extracellular vesicles, has induced certain advantages including higher levels within fluids and lower operative expenses. Imaging biomarkers, started around 2004, are identified in vivo upon their binding by radiolabeled molecules subsequently revealed in the brain by positron emission tomography and/or other imaging techniques. A positive point for the latter approach is the quantitation of results, but expenses are much higher. At present, both types of biomarker are being extensively employed to study Alzheimer’s and other neurodegenerative diseases, investigated from the presymptomatic to mature stages. In conclusion, biomarkers have revolutionized scientific and medical research and practice. Diagnosis, which is often inadequate when based on medical criteria only, has been recently improved by the multiplicity and specificity of biomarkers. Analogous results have been obtained for prognosis. In contrast, improvement of therapy has been limited or fully absent, especially for Alzheimer’s in which progress has been inadequate. An urgent need at hand is therefore the progress of a new drug trial design together with patient management in clinical practice.

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Distinct Imaging Modalities in Head and Neck Cancer: Benefits and Drawbacks

International Journal of Research in Pharmaceutical Sciences ◽

10.26452/ijrps.v11ispl4.4554 ◽

2020 ◽

Vol 11 (SPL4) ◽

pp. 2777-2784

Author(s):

Dana Merin ◽

Roshni P R

Keyword(s):

Head And Neck Cancer ◽

Head And Neck ◽

Neck Cancer ◽

Imaging Techniques ◽

Precise Determination ◽

Imaging Biomarkers ◽

Selection Strategies ◽

Positron Emission ◽

Before And After ◽

Oncological Imaging

This review mainly focuses on the distinct imaging techniques in for head and neck cancer (HNC), its altered techniques used in diagnosis and its applications. It also depicts the upcoming imaging methods present in the field of HNC causing areas. It explains precise determination regarding the degree and extends of neoplasm. We mainly look on to the MRI(Magnetic resonance imaging), PET(Positron emission tomography), CT (computed tomography)imaging biomarkers for the management of HNC. It plays an important role in the therapy selection strategies and also enhances the therapeutic ratio in the management of HNC. The role of imaging techniques become increasingly more crucial in the management process in locally progressed head and neck squamous cell carcinoma(HNSCC). In this structure, PET allows non-invasive assessment of a range of tumour biomarkers such as metabolism, hypoxia and proliferation. MRI techniques such as can characterize different tissues by probing into their microstructure, providing a novel methodology in oncological imaging. CT, MRI, and PET/CT are widely used to determine the presence and extent of the tumours before and after treatment. This review depicts a synopsis of the most recent imaging strategies and imaging recommendations for every one of the different strides along the clinical way of patients with head and neck malignant growth.

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Focal changes in brain energy and phospholipid metabolism in first-episode schizophrenia

The British Journal of Psychiatry ◽

10.1192/bjp.184.5.409 ◽

2004 ◽

Vol 184 (5) ◽

pp. 409-415 ◽

Cited By ~ 39

Author(s):

J. Eric Jensen ◽

Jodi Miller ◽

Peter C. Williamson ◽

Richard W J. Neufeld ◽

Ravi S. Menon ◽

...

Keyword(s):

Healthy Volunteers ◽

Imaging Techniques ◽

High Energy ◽

Brain Regions ◽

Anterior Cingulate ◽

First Episode ◽

Resonance Spectroscopy ◽

Membrane Breakdown ◽

First Episode Schizophrenia

BackgroundMembrane phospholipid and high-energy abnormalities measured with phosphorus magnetic resonance spectroscopy (31P-MRS) have been reported in patients with schizophrenia in several brain regions.AimsUsing improved imaging techniques, previously inaccessible brain regions were examined in patients with first-episode schizophrenia and healthy volunteers with 4.0 T 31P-MRS.MethodBrain spectra were collected in vivo from 15 patients with first-episode schizophrenia and 15 healthy volunteers from 15 cm3 effective voxels in the thalamus, cerebellum, hippocampus, anterior/posterior cingulate, prefrontal cortex and parieto-occipital cortex.ResultsPeople with first-episode schizophrenia showed increased levels of glycerophosphocholine in the anterior cingulate. Inorganic phosphate, phosphocreatine and adenosine triphosphate concentrations were also increased in the anterior cingulate in this group.ConclusionsThe increased phosphodiester and high-energy phosphate levels in the anterior cingulate of brains of people with first-episode schizophrenia may indicate neural overactivity in this region during the early stages of the illness, resulting in increased excitotoxic neural membrane breakdown.

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