Identification and Characterization of Secondary Neural Tube-Derived Embryonic Neural Stem Cells In Vitro

Shaker, Mohammed R.,Kim, Joo Yeon,Kim, Hyun,Sun, Woong Mary Ann Liebert 2015 STEM CELLS AND DEVELOPMENT Vol.24 No.10

<P>Secondary neurulation is an embryonic progress that gives rise to the secondary neural tube, the precursor of the lower spinal cord region. The secondary neural tube is derived from aggregated Sox2-expressing neural cells at the dorsal region of the tail bud, which eventually forms rosette or tube-like structures to give rise to neural tissues in the tail bud. We addressed whether the embryonic tail contains neural stem cells (NSCs), namely secondary NSCs (sNSCs), with the potential for self-renewal in vitro. Using in vitro neurosphere assays, neurospheres readily formed at the rosette and neural-tube levels, but less frequently at the tail bud tip level. Furthermore, we identified that sNSC-generated neurospheres were significantly smaller in size compared with cortical neurospheres. Interestingly, various cell cycle analyses revealed that this difference was not due to a reduction in the proliferation rate of NSCs, but rather the neuronal commitment of sNSCs, as sNSC-derived neurospheres contain more committed neuronal progenitor cells, even in the presence of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). These results suggest that the higher tendency for sNSCs to spontaneously differentiate into progenitor cells may explain the limited expansion of the secondary neural tube during embryonic development.</P>

A criterion combined of bulk and surface lithium storage to predict the capacity of porous carbon lithium-ion battery anodes: lithium-ion battery anode capacity prediction

Shaker Majid,Ghazvini Ali Asghar Sadeghi,Qureshi Faisal Raza,Riahifar Reza 한국탄소학회 2021 Carbon Letters Vol.31 No.5

The high level of lithium storage in synthetic porous carbons has necessitated the development of accurate models for estimating the specifc capacity of carbon-based lithium-ion battery (LIB) anodes. To date, various models have been developed to estimate the storage capacity of lithium in carbonaceous materials. However, these models are complex and do not take into account the efect of porosity in their estimations. In this paper, a novel model is proposed to predict the specifc capacity of porous carbon LIB anodes. For this purpose, a new factor is introduced, which is called normalized surface area. Considering this factor, the contribution of surface lithium storage can be added to the lithium stored in the bulk to have a better prediction. The novel model proposed in this study is able to estimate the lithium storage capacity of LIB anodes based on the porosity of porous carbons for the frst time. Benefting porosity value (specifc surface area) makes the predictions quick, facile, and sensible for the scientists and experts designing LIBs using porous carbon anodes. The predicted capacities were compared with that of the literature reported by experimental works. The remarkable consistency of the measured and predicted capacities of the LIB anodes also confrms the validity of the approach and its reliability for further predictions.

Embryonal Neuromesodermal Progenitors for Caudal Central Nervous System and Tissue Development

Shaker, Mohammed R.,Lee, Ju-Hyun,Sun, Woong The Korean Neurosurgical Society 2021 Journal of Korean neurosurgical society Vol.64 No.3

Neuromesodermal progenitors (NMPs) constitute a bipotent cell population that generates a wide variety of trunk cell and tissue types during embryonic development. Derivatives of NMPs include both mesodermal lineage cells such as muscles and vertebral bones, and neural lineage cells such as neural crests and central nervous system neurons. Such diverse lineage potential combined with a limited capacity for self-renewal, which persists during axial elongation, demonstrates that NMPs are a major source of trunk tissues. This review describes the identification and characterization of NMPs across multiple species. We also discuss key cellular and molecular steps for generating neural and mesodermal cells for building up the elongating trunk tissue.

Ac and Dc conductivities of polyaniline/poly vinyl formal blend films

Shaker Ebrahim,Abdel-Hady Kashyout,Moataz Soliman 한국물리학회 2009 Current Applied Physics Vol.9 No.3

The synthesis and characterization of polyaniline (PANI)/poly vinyl formal (PVF) blend films were carried out in this work. Polyaniline base was doped using dodecylbenzene sulfonic acid (DBSA). These blend films were characterized by UV–Visible, FTIR spectra and scanning electron microscopy (SEM) to investigate their optical, structural and morphological properties. It was found that the percolation threshold of these blends is 4.4 wt% of PANI. The dc and ac conductivities of these blend films have been measured at a temperature range from 300 to 100 K in the frequency range of 10 kHz to 1 MHz. The electrical conductivity of the blend films enhanced with the increase of polyaniline amount up to a value of 2.5 × 10-4 S cm-1 at 65 wt% of polyaniline. The dc conductivity of the PANI/PVF blend films follows the three-dimension variable range hopping. Temperature variation of frequency exponents in this blend suggests that ac conduction is attributed to be correlated barrier hopping. The synthesis and characterization of polyaniline (PANI)/poly vinyl formal (PVF) blend films were carried out in this work. Polyaniline base was doped using dodecylbenzene sulfonic acid (DBSA). These blend films were characterized by UV–Visible, FTIR spectra and scanning electron microscopy (SEM) to investigate their optical, structural and morphological properties. It was found that the percolation threshold of these blends is 4.4 wt% of PANI. The dc and ac conductivities of these blend films have been measured at a temperature range from 300 to 100 K in the frequency range of 10 kHz to 1 MHz. The electrical conductivity of the blend films enhanced with the increase of polyaniline amount up to a value of 2.5 × 10-4 S cm-1 at 65 wt% of polyaniline. The dc conductivity of the PANI/PVF blend films follows the three-dimension variable range hopping. Temperature variation of frequency exponents in this blend suggests that ac conduction is attributed to be correlated barrier hopping.

Synthesis, Characterization and Spectrophotometric Studies of Seven Novel Antibacterial Hydrophilic Iron(II) Schiff Base Amino Acid Complexes

Shaker, Ali M.,Nassr, Lobna A.E.,Adam, Mohamed S.S.,Mohamed, Ibrahim M.A. Korean Chemical Society 2013 대한화학회지 Vol.57 No.5

A series of new Iron(II) Schiff base amino acid complexes derived from the condensation of amino acid and sodium 2-hydroxybenzaldehyde-5-sulfonate have been synthesized. The complexes were characterized by elemental, electronic, IR spectral analyses and conductance measurements. The stability and solubility of the prepared complexes were determined. Two spectral methods used to determine the stoichiometry of the prepared complexes which exhibited divalent tridentate coordination and formed chelates of octahedral structures. The antibacterial activity of the prepared complexes has been tested against Bacillus cereus, Pseudomonas aeruginosa and Micrococcus bacteria. The effect of HCl on investigated complexes studied spectrophotometrically.

Synthesis of Some New Cytidine and Inosine Derivatives

Shaker Youssif,Enaiat K. Mohamed,Ahmed F. Sayed Ahmed,Amira A. Ghoneim 대한화학회 2005 Bulletin of the Korean Chemical Society Vol.26 No.12

The oxidation of cytidine 1 and inosine 5 by sodium metaperiodate followed by the reaction of the product with CH3I in NaOH afforded 2',4'-dihydroxyhexopyranosyl derivatives 2 and 14 respectively. The reaction of thiophene-2-carboxylic acid or furfural with cytidine were taken place via cycloaddition afforded adducts 3 and 4 respectivily. The bromination of inosine 5 or its 2',3'-O-isopropylidine inosine 6 led to the formation of 8-bromoanalogue 7 and 8, respectively. The reaction of 8-bromo-2',3'-O-isopropylidine inosine (8) with ethyl glycinate hydrochloride afforded 8-ethoxycarbonylmethylaminoinosine 9. The alkylation of the compound 6 with urea led to the formation of 3-carbonylaminoinosine 10. The oxidation of 6 with DCC afforded 4'-formyl derivative 11, which on reaction with ethyl glycinate hydrochloride followed by reaction with sodium cyanoborohydride afforded 12, while the treatment of dialdehyde inosine 13 with ethyl cyanoacetate in the presence of 0.5 N NaOH afforded compound 15.

Synthesis of Some New Cytidine and Inosine Derivatives

Youssif, Shaker,Mohamed, Enaiat K.,Sayed Ahmed, Ahmed F.,Ghoneim, Amira A. Korean Chemical Society 2005 Bulletin of the Korean Chemical Society Vol.26 No.12

The oxidation of cytidine 1 and inosine 5 by sodium metaperiodate followed by the reaction of the product with $CH_3I$ in NaOH afforded 2',4'-dihydroxyhexopyranosyl derivatives 2 and 14 respectively. The reaction of thiophene-2-carboxylic acid or furfural with cytidine were taken place via cycloaddition afforded adducts 3 and 4 respectivily. The bromination of inosine 5 or its 2',3'-O-isopropylidine inosine 6 led to the formation of 8-bromoanalogue 7 and 8, respectively. The reaction of 8-bromo-2',3'-O-isopropylidine inosine (8) with ethylglycinate hydrochloride afforded 8-ethoxycarbonylmethylaminoinosine 9. The alkylation of the compound 6 with urea led to the formation of 3-carbonylaminoinosine 10. The oxidation of 6 with DCC afforded 4'-formyl derivative 11, which on reaction with ethyl glycinate hydrochloride followed by reaction with sodium cyanoborohydride afforded 12, while the treatment of dialdehyde inosine 13 with ethyl cyanoacetate in the presence of 0.5 N NaOH afforded compound 15.

Conjecture on the evolution of Boshruyeh city by a typological, topological and morphological study of its courtyards

Reza Shaker Ardakani,Hamed Akhgar 서울시립대학교 도시과학연구원 2012 도시과학국제저널 Vol.16 No.3

In order to demonstrate the historical image of a city, historical texts and field surveys are usually used. Field surveys and archeological excavations seem to be the only accessible options when there is a shortage of reliable sources and written texts. The question raised in this study is: how can the historical evolution of a city be described before any archeological surmising if there are no reliable historical texts. The purpose of this article is to show the gradual formation of urban texture on the basis of the urban morphology. The historical city of Boshruyeh has been studied by using the descriptive-analytic method. In this regard the historical image of this city has been portrayed by considering the literature and particularly Norberg-Schulz’s theory, on three levels: the typological, topological and morphological study of its courtyards using aerial photographs and Geographical Information System (GIS) analysis.

Effect of a two bearing lines deck on the bridge substructure

Fatemeh Shaker,Alireza Rahai 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.81 No.2

This research evaluated the different types of deck to pier connections effects (one or two elastomeric bearing lines and rigid) on a concrete bridges. Three-dimensional bridge models behavior with different deck to pier connections and different distances of two bearing lines were studied under the service load. Also, the detailed connection system with two elastomeric bearing lines was modeled to evaluate the effect of changing distance between two-lines. Results indicated that the proper location of elastomeric bearings has a major impact on the transferring forces to the substructure. Double elastomeric bearing lines have a behavior between one line and rigid connections. Transferring bending moment to the substructure in two-lines is more than the corresponding value of the one line. Moreover, an increase in the distance of two-lines lead to a significant increase in the rotational stiffness of the connection, and an analytical solution was investigated for their relation. In fact, the semi-rigidity effect of this connection and its change due to the distance of bearings should be considered in the design process.

User guide for the discovery of potential drugs via protein structure prediction and ligand docking simulation

bilal shaker,Myung-Sang Yu,Jingyu Lee,Yongmin Lee,Chanjin Jung,Dokyun Na 한국미생물학회 2020 The journal of microbiology Vol.58 No.3

Due to accumulating protein structure information and advances in computational methodologies, it has now become possible to predict protein-compound interactions. In biology, the classic strategy for drug discovery has been to manually screen multiple compounds (small scale) to identify potential drug compounds. Recent strategies have utilized computational drug discovery methods that involve predicting target protein structures, identifying active sites, and finding potential inhibitor compounds at large scale. In this protocol article, we introduce an in silico drug discovery protocol. Since multi-drug resistance of pathogenic bacteria remains a challenging problem to address, UDP-N-acetylmuramate- L-alanine ligase (murC) of Acinetobacter baumannii was used as an example, which causes nosocomial infection in hospital setups and is responsible for high mortality worldwide. This protocol should help microbiologists to expand their knowledge and research scope.