scholarly journals Revealing the early stages of carbamazepine crystallization by cryoTEM and 3D electron diffraction

IUCrJ ◽  
2021 ◽  
Vol 8 (6) ◽  
Author(s):  
Edward T. Broadhurst ◽  
Hongyi Xu ◽  
Simon Parsons ◽  
Fabio Nudelman
Keyword(s):  
Phase Separation ◽  
Electron Diffraction ◽  
Early Stage ◽  
Active Pharmaceutical Ingredient ◽  
Time Resolved ◽  
Carbamazepine Dihydrate ◽  
Early Stages ◽  
3D Electron

Time-resolved carbamazepine crystallization from wet ethanol has been monitored using a combination of cryoTEM and 3D electron diffraction. Carbamazepine is shown to crystallize exclusively as a dihydrate after 180 s. When the timescale was reduced to 30 s, three further polymorphs could be identified. At 20 s, the development of early stage carbamazepine dihydrate was observed through phase separation. This work reveals two possible crystallization pathways present in this active pharmaceutical ingredient.

Electron Channeling Patterns

1977 ◽  
Vol 35 ◽  
pp. 12-13
Author(s):  
David C. Joy
Keyword(s):  
Electron Diffraction ◽  
Incidence Angle ◽  
Photographic Plate ◽  
Diffraction Effect ◽  
Angle Of Incidence ◽  
Bulk Single Crystal ◽  
Time Resolved ◽  
Electron Channeling ◽  
Spatially Resolved ◽  
Large Bulk

Electron channeling patterns (ECP) were first found by Coates (1967) while observing a large bulk, single crystal of silicon in a scanning electron microscope. The geometric pattern visible was shown to be produced as a result of the changes in the angle of incidence, between the beam and the specimen surface normal, which occur when the sample is examined at low magnification (Booker, Shaw, Whelan and Hirsch 1967).A conventional electron diffraction pattern consists of an angularly resolved intensity distribution in space which may be directly viewed on a fluorescent screen or recorded on a photographic plate. An ECP, on the other hand, is produced as the result of changes in the signal collected by a suitable electron detector as the incidence angle is varied. If an integrating detector is used, or if the beam traverses the surface at a fixed angle, then no channeling contrast will be observed. The ECP is thus a time resolved electron diffraction effect. It can therefore be related to spatially resolved diffraction phenomena by an application of the concepts of reciprocity (Cowley 1969).

A Time-Resolved Low-Angle Light Scattering Apparatus. Application to Phase Separation Problems in Polymer Systems

2001 ◽  
Vol 66 (6) ◽  
pp. 973-982 ◽  
Author(s):  
Čestmír Koňák ◽  
Jaroslav Holoubek ◽  
Petr Štěpánek
Keyword(s):  
Phase Separation ◽  
Light Scattering ◽  
Signal To Noise Ratio ◽  
Scattered Light ◽  
Ccd Camera ◽  
Time Resolved ◽  
Polymer Systems ◽  
Software Analysis ◽  
Phase Separation Kinetics ◽  
Small Angle Light Scattering

A time-resolved small-angle light scattering apparatus equipped with azimuthal integration by means of a conical lens or software analysis of scattering patterns detected with a CCD camera was developed. Averaging allows a significant reduction of the signal-to-noise ratio of scattered light and makes this technique suitable for investigation of phase separation kinetics. Examples of applications to time evolution of phase separation in concentrated statistical copolymer solutions and dissolution of phase-separated domains in polymer blends are given.

scholarly journals Improving data quality for 3D electron diffraction (3DED) by Gatan Image Filter (GIF)

2021 ◽  
Vol 27 (S1) ◽  
pp. 198-203
Author(s):  
Taimin Yang ◽  
Hongyi Xu ◽  
Xiaodong Zou
Keyword(s):  
Electron Diffraction ◽  
Data Quality ◽  
Image Filter ◽  
3D Electron

scholarly journals On the Role of Poly-Glutamic Acid in the Early Stages of Iron(III) (Oxy)(hydr)oxide Formation

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 715
Author(s):  
Miodrag J. Lukić ◽  
Felix Lücke ◽  
Teodora Ilić ◽  
Katharina Petrović ◽  
Denis Gebauer
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Phase Separation ◽  
Fourier Transform Infrared Spectroscopy ◽  
Fourier Transform Infrared ◽  
Nucleation Theory ◽  
Classical Nucleation Theory ◽  
Oxide Formation ◽  
Early Stages ◽  
Titration Assay

Nucleation of minerals in the presence of additives is critical for achieving control over the formation of solids in biomineralization processes or during syntheses of advanced hybrid materials. Herein, we investigated the early stages of Fe(III) (oxy)(hydr)oxide formation with/without polyglutamic acid (pGlu) at low driving force for phase separation (pH 2.0 to 3.0). We employed an advanced pH-constant titration assay, X-ray diffraction, thermal analysis with mass spectrometry, Fourier Transform infrared spectroscopy, and scanning electron microscopy. Three stages were observed: initial binding, stabilization of Fe(III) pre-nucleation clusters (PNCs), and phase separation, yielding Fe(III) (oxy)(hydr)oxide. The data suggest that organic–inorganic interactions occurred via binding of olation Fe(III) PNC species. Fourier Transform Infrared Spectroscopy (FTIR) analyses revealed a plausible interaction motif and a conformational adaptation of the polypeptide. The stabilization of the aqueous Fe(III) system against nucleation by pGlu contrasts with the previously reported influence of poly-aspartic acid (pAsp). While this is difficult to explain based on classical nucleation theory, alternative notions such as the so-called PNC pathway provide a possible rationale. Developing a nucleation theory that successfully explains and predicts distinct influences for chemically similar additives like pAsp and pGlu is the Holy Grail toward advancing the knowledge of nucleation, early growth, and structure formation.

scholarly journals Platelets as messengers of early-stage cancer

2021 ◽  
Author(s):  
Siamack Sabrkhany ◽  
Marijke J. E. Kuijpers ◽  
Mirjam G. A. oude Egbrink ◽  
Arjan W. Griffioen
Keyword(s):  
Tumor Angiogenesis ◽  
Blood Test ◽  
Early Stage ◽  
Human Studies ◽  
Early Stage Cancer ◽  
Reciprocal Interaction ◽  
Early Stages ◽  
New Strategy ◽  
Mrna Content

AbstractPlatelets have an important role in tumor angiogenesis, growth, and metastasis. The reciprocal interaction between cancer and platelets results in changes of several platelet characteristics. It is becoming clear that analysis of these platelet features could offer a new strategy in the search for biomarkers of cancer. Here, we review the human studies in which platelet characteristics (e.g., count, volume, protein, and mRNA content) are investigated in early-stage cancer. The main focus of this paper is to evaluate which platelet features are suitable for the development of a blood test that could detect cancer in its early stages.

3D electron diffraction of mono- and few-layer MoS2

Micron ◽  
2021 ◽  
Vol 146 ◽  
pp. 103071
Author(s):  
Tatiana E. Gorelik ◽  
Berkin Nergis ◽  
Tobias Schöner ◽  
Janis Köster ◽  
Ute Kaiser
Keyword(s):  
Electron Diffraction ◽  
3D Electron

scholarly journals The expression of microRNA-331-3p and microRNA-23b3 in Egyptian patients with early-stage hepatocellular carcinoma in hepatitis C-related liver cirrhosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Reham A. Aboelwafa ◽  
Walid Ismail Ellakany ◽  
Marwa A. Gamaleldin ◽  
Marwa A. Saad
Keyword(s):  
Hepatocellular Carcinoma ◽  
Liver Cirrhosis ◽  
Hepatitis C ◽  
Early Stage ◽  
Group Iii ◽  
Real Time Quantitative Pcr ◽  
Early Stages ◽  
Group I ◽  
Egyptian Patients ◽  
Cirrhotic Patients

Abstract Background Hepatocellular carcinoma and hepatitis C are strongly associated. The current work aimed to study the expression levels of microRNA-331-3p and microRNA-23b-3p as propable biomarkers for detecting liver cancer (HCC) at its early stages in patients with HCV-related liver cirrhosis. The current prospective study included two hundred participants, divided into three groups: group I, 100 patients with HCV-related liver cirrhosis; group II, 50 HCC patients at early stages; and group III, 50 apparentlyhealthy controls. All patients had routine laboratory workup and ultrasound hepatic assessment. Values of microRNA-331-3p and microRNA-23b-3p were measured by real-time quantitative PCR. Results Levels of miR-331-3p were significantly higher in HCC patients than in cirrhotic patients and controls (p < 0.001), while levels of miR-23b-3p were significantly lower in HCC patients compared to cirrhotics and controls (p < 0.001). ROC curve revealed that miR-23b-3p had 80% sensitivity and 74% specificity, miR-331-3p had 66% sensitivity and 61% specificity, and AFP had 64% sensitivity and 61% specificity of 61% in discrimination between HCC patients from controls. Conclusion Serum miR-23b-3p is a more effective predictor than miR-331-3p and AFP for the development of hepatocellular carcinoma in hepatitis C (HCV)-related cirrhotic patients.

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