scholarly journals Pectin-Coated Curcumin-Chitosan Microparticles Crosslinked with Mg2+ for Delayed Drug Release in the Digestive System

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Seung Won Hwang ◽  
Jae Sup Shin
Keyword(s):  
Release Rate ◽  
Digestive System ◽  
Crosslinking Agent ◽  
Vital Role ◽  
Colonic Disease ◽  
Chitosan Microparticles ◽  
Drug Delivery Carrier ◽  
First Time ◽  
Delayed Drug Release ◽  
Release Profiles

Curcumin-loaded chitosan-pectin microparticles based on polymeric microencapsulation were prepared by two methods to delay the release of curcumin in the digestive system, employing Mg2+ as a pectin-crosslinking agent for the first time. Pectin-coated curcumin-chitosan microparticles (C-g-PMg) and curcumin-loaded chitosan-pectin composite microparticles (C-PMg-g) were formulated, and their release profiles at pH 1.2 and at pH 6.8 were tested. The former (C-g-PMg) showed slower curcumin release profiles than the latter (C-PMg-g) because the C-g-PMg are composed of two layers, a chitosan-glutaraldehyde layer and a pectin-Mg2+ layer, which together hold the curcumin for a longer duration. Of the pectin-coated microparticles, those crosslinked with Mg2+ showed a slower release rate than those crosslinked with Ca2+, but the former showed a faster release rate at pH 6.8 in the presence of pectinase, acting as a promising drug delivery carrier for treating a colonic disease. The pectin layer and the pectin-crosslinking agent play a vital role in prolonging the release of curcumin until pectin is degraded by pectinase.

MiRNA-145 and Its Direct Downstream Targets in Digestive System Cancers: A Promising Therapeutic Target

2020 ◽  
Vol 26 ◽  
Author(s):  
Yini Ma ◽  
Xiu Cao ◽  
Guojuan Shi ◽  
Tianlu Shi
Keyword(s):  
Digestive System ◽  
Target Genes ◽  
Malignant Neoplasm ◽  
Vital Role ◽  
Diagnostic Biomarkers ◽  
Cellular Processes ◽  
Promising Therapeutic Target ◽  
Direct Target ◽  
Potential Strategy

: MicroRNAs (miRNAs) play a vital role in the onset and development of many diseases, including cancers. Emerging evidence shows that numerous miRNAs have the potential to be used as diagnostic biomarkers for cancers, and miRNA-based therapy may be a promising therapy for the treatment of malignant neoplasm. MicroRNA-145 (miR-145) has been considered to play certain roles in various cellular processes, such as proliferation, differentiation and apoptosis, via modulating expression of direct target genes. Recent reports show that miR-145 participates in the progression of digestive system cancers, and plays crucial and novel roles for cancer treatment. In this review, we summarize the recent knowledge concerning the function of miR-145 and its direct targets in digestive system cancers. We discuss the potential role of miR-145 as valuable biomarkers for digestive system cancers and how miR-145 regulates these digestive system cancers via different targets to explore the potential strategy of targeting miR-145.

European Mail Armour

2021 ◽  
Author(s):  
Martijn A. Wijnhoven
Keyword(s):  
Early Modern ◽  
Middle Ages ◽  
Iron Age ◽  
Early Modern Period ◽  
Vital Role ◽  
Military Technology ◽  
Roman Army ◽  
Solid Foundation ◽  
First Time

Mail armour (commonly mislabelled 'chainmail') was used for more than two millennia on the battlefield. After its invention in the Iron Age, mail rapidly spread all over Europe and beyond. The Roman army, keen on new military technology, soon adopted mail armour and used it successfully for centuries. Its history did not stop there and mail played a vital role in warfare during the Middle Ages up to the Early Modern Period. Given its long history, one would think mail is a well-documented material, but that is not the case. For the first time, this books lays a solid foundation for the understanding of mail armour and its context through time. It applies a long-term multi-dimensional approach to extract a wealth of as yet untapped information from archaeological, iconographic and written sources. This is complemented with technical insights on the mail maker’s chaîne opératoire.

scholarly journals First report on cyanobacterial flora from Masirah Island, Sultanate of Oman

Algologia ◽  
2020 ◽  
Vol 30 (4) ◽  
pp. 440-451
Author(s):  
M. Shamina ◽  
Keyword(s):  
Environmental Conditions ◽  
Food Industry ◽  
Vital Role ◽  
Taxonomic Composition ◽  
Climatic Conditions ◽  
Taxonomic Classification ◽  
Biofuel Production ◽  
Sultanate Of Oman ◽  
First Report ◽  
First Time

Cyanobacteria are organisms which play a vital role in various molecular and biotechnological aspects in food industry, agriculture, pharmaceuticals, neutraceuticals, biofuel production, etc., it is necessary to understand its adaptability to various environmental conditions. Furthermore it is equally important to discover new cyanobacterial taxa and with it occasional changes in taxonomic classification, thus the author set out to study cyanobacteria in extreme climatic conditions of desert, where temperatures are mostly above 45 oC. The taxonomic composition of cyanobacteria of Masirah Island, Sultanate of Oman, was studied for the first time. The studied samples were collected during the period of 2017–2019. The ten samples belonged to two orders: Oscillatoriales Schaffner and Synechococcales L.Hoffmann, Komárek & J.Kastovsky. All of them were filamentous non-heterocyst forms. Three species belonged to the genus Leptolyngbya Anagn. & Komárek, the genera Oscillatoria Vaucher ex Gomont and Lyngbya C.Agardh ex Gomont were represented by two species each, while the genera Pseudanabena Lauterborn, Planktolyngbya Anagn. & Komárek and Geitlerinema (Anagn. & Komárek) Anagn. were one species.

scholarly journals Evaluating the Flow and Release Profiles of Ibuprofen Formulations by Increasing the Binder Concentration

2021 ◽  
Vol 16 (2) ◽  
pp. 111-117
Author(s):  
B.B. Mohammed ◽  
E.J. John ◽  
G.T. Abdulsalam ◽  
K.P. Bahago
Keyword(s):  
Release Rate ◽  
Active Drug ◽  
Release Profile ◽  
Wet Granulation ◽  
Flow Properties ◽  
Disintegration Time ◽  
Weight Variation ◽  
Tablet Dissolution ◽  
Tablet Formulations ◽  
Release Profiles

Background: Tablets must be able to release the active drug in the gastrointestinal tract for absorption. The release profile of solid pharmaceutical dosage formulations can be quantified by assessing the disintegration and dissolution times tests. Binders are adhesives either from sugar or polymeric material that are added to tablet formulations to provide the cohesiveness required for the bonding together of the granules under compaction to form tablets.Objective: The objective of the study was to formulate and assess ibuprofen tablets using different concentrations of binders (Acacia and Gelatin).Methods: The granules were prepared using wet granulation method and analysed for flow properties based on USP/NF protocols. After granule compression, the tablets release profiles were thereafter assessed via the tablet dissolution and disintegration tests.Results: Weight variation, thickness and diameter were within the acceptable values for all batches indicative of a uniform flow. Batches with binder concentrations of 10 % and 20 % failed disintegration test due to a disintegration time above 15 min while the release rate for batches 1 and 4 was about 88 % in 60 min as against the other batches whose release rate was less than 50 % in 60 min as a result of increasing their binder concentrations.Conclusion: The study concluded that increasing the concentration of acacia and gelatin above 5% led to a decrease in percentage of drug released and an increase in disintegration time above 30 mins because 5% batches gave the best release profiles.

scholarly journals PhotoATRP Induced Self-Assembly (PhotoATR-PISA) Enables Simplified Synthesis of Responsive Polymer Nanoparticles in One-Pot

2020 ◽  
Author(s):  
Ali Shahrokhinia ◽  
Randall Scanga ◽  
Priyanka Biswas ◽  
James Reuther
Keyword(s):  
Self Assembly ◽  
Glycidyl Methacrylate ◽  
Uv Light ◽  
Copper Catalyst ◽  
Crosslinking Agent ◽  
Polymer Nanoparticles ◽  
One Pot ◽  
Responsive Polymer ◽  
Catalyst Systems ◽  
First Time

<p><b>ABSTRACT:</b> Photo-controlled atom transfer radical polymerization (PhotoATRP) was implemented, for the first time, to accomplish polymerization induced self-assembly (PISA) mediated by UV light (λ = 365 nm) using ppm levels (ca. < 20 ppm) of copper catalyst at ambient temperature. Using Cu<sup>II</sup>Br<sub>2</sub>/tris(pyridin-2-ylmethyl)amine (TPMA) catalyst systems, PISA was per-formed all in one-pot starting from synthesis of solvophilic poly(oligo(ethylene oxide) methyl ether methacrylate) (POEGMA) blocks to core-crosslinked nanoparticles (NPs) utilizing poly(glycidyl methacrylate) (PGMA) and N,N-cystamine bismethacrylamide (CBMA) as the solvophobic copolymer and crosslinking agent, respectively. Sequential chain-extensions were performed for PGMA demonstrating capabilities for accessing multi-block copolymers with temporal control via switching the UV light on and off. Further, core-crosslinking of PISA nanoparticles was performed via the slow incorporation of the CBMA enabling one-pot crosslinking during the PISA process. Finally, the disulfide installed in the CBMA core-crosslinks allowed for the stimuli-triggered dissociation of nanoparticles using DL-dithiothreitol at acidic pH.</p>

scholarly journals PD-1 Suppresses the Osteogenic and Odontogenic Differentiation of Stem Cells From Dental Apical Papilla via Targeting SHP2/NF-κB axis

2021 ◽  
Author(s):  
Na Li ◽  
Zehan Li ◽  
Lin Fu ◽  
Ming Yan ◽  
Yanqiu Wang ◽  
...  
Keyword(s):  
Vital Role ◽  
Cell Counting ◽  
Alizarin Red ◽  
Odontogenic Differentiation ◽  
Root Dentin ◽  
Apical Papilla ◽  
Effect Of Pd ◽  
First Time ◽  
The Relationship

Abstract BackgroundStem cells from the apical papilla (SCAPs) are important for tooth root development and regeneration of root dentin. Here, we examined the expression of programmed cell death protein-1 (PD-1) in SCAPs and investigated the effect of PD-1 on odontogenic and osteogenic differentiation and the relationship between PD-1 and cell differentiation and SHP2/NF-κB signals.MethodsSCAPs were obtained culture in the related medium. The proliferation ability was evaluated by cell counting kit 8 and 5‐ethynyl‐20‐deoxyuridine (EdU) assay. Alkaline phosphatase (ALP) activity assay, ALP staining, western blot, real-time RT-PCR, Alizarin Red S staining, and immunofluorescence staining were performed to explore the osteo/odontogenic potential and the involvement of SHP2/NF-κB pathways. Besides, we transplanted SCAPs component into mouse calvaria defects to evaluate osteogenesis in vivo. ResultsWe found that human SCAPs expressed PD-1 for the first time. PD-1 knockdown enhanced the osteo/odontogenic differentiation of SCAPs by suppressing SHP2 pathway and activating NF-κB pathway. Overexpression of PD-1 inhibited the osteogenesis and odontogenesis of SCAPs via activation of SHP2 signal and inhibition of NF-κB pathway. ConclusionPD-1 activated SHP2 signal to block NF-κB signal and then played a vital role in osteo/odontogenic differentiation of SCAPs.

Electric features of dislocations and electric force between dislocations

2020 ◽  
pp. 108128652096564
Author(s):  
Yuanjie Huang
Keyword(s):  
Electric Field ◽  
Dielectric Materials ◽  
Dislocation Motion ◽  
Vital Role ◽  
Dislocation Dynamics ◽  
Electric Force ◽  
Fundamental Knowledge ◽  
Large Dielectric Constant ◽  
Net Charges ◽  
First Time

Dislocations and dislocation dynamics are the cores of material plasticity. In this work, the electric features of dislocations were investigated theoretically. An intrinsic electric field around a single dislocation was revealed. In addition to the well-known Peach–Koehler force, it was established that an important intrinsic electric force exists between dislocations, which is uncovered here for the first time and has been neglected since the discovery of dislocations. The electric forces may be large and sometimes could exceed the Peach–Koehler force for metals and some dielectric materials with large dielectric constant. Therefore, the electric force is anticipated to play a vital role in dislocation dynamics and material plasticity. Moreover, an external electric field could exert an electric force on dislocations and a threshold electric field was subsequently discovered above which this force enables dislocations to glide. Interestingly, it was found that some dislocations move in one direction, but others move in reverse in an identical electric field, which is in agreement with experimental observations. Despite dislocation motion under an electric field, to one’s surprise, both edge and screw dislocations do not carry net charges by themselves, which may tackle the long-standing puzzle on the charges of dislocations. These findings may supply people with new fundamental knowledge on dislocations as well as dislocation dynamics, and may assist people in understanding related phenomena.

scholarly journals The role of mucilage envelope in the endozoochory of selected plant taxa

2020 ◽  
Vol 108 (1) ◽  
Author(s):  
A. Kreitschitz ◽  
E. Haase ◽  
S. N. Gorb
Keyword(s):  
Digestive System ◽  
Columba Livia ◽  
Local Scale ◽  
Ocimum Basilicum ◽  
Long Distance Dispersal ◽  
Morphological Adaptation ◽  
Long Distance ◽  
Germination Ability ◽  
First Time

AbstractMyxodiaspory (formation of mucilage envelope around seeds and fruits) is a common adaptation to dry habitats known in many families of Angiosperms. The mucilage envelope of some seeds seems to be also a unique morphological adaptation which protects myxospermatic diaspores while passing through the bird’s digestive system. To evaluate the protective potential of mucilage, we fed the diaspores of seven plant species (representing three different mucilage types and three species of non-mucilaginous plants) to pigeons, Columba livia domestica. Twenty-four hours later, we collected the droppings of pigeons and examined a total of 18,900 non-destroyed diaspores to check for mucilage presence and germination ability. Out of all the examined diaspores, 4.5% were mucilaginous seeds. Among them, the highest number (12.2–13.5%) of viable diaspores belonged to the hemicellulosic type of mucilage (from Plantago species). Only 3.7% of germinating diaspores with pectic mucilage (Linum usitatissimum) were collected, and no seeds representing cellulosic mucilage (e.g., Ocimum basilicum). For non-mucilaginous plants, we collected only a few individual seeds (0.1% out of 8100 seeds used). We noted that the mucilaginous seeds found in the droppings were able to germinate; however, the germination ability was generally smaller in comparison to the control (i.e., not digested) seeds. Our results revealed that the presence of mucilage envelope has an impact on diaspore dispersal and survivability. With our experiments, we demonstrated for the first time that the mucilage envelope, especially of the non-cellulosic type, supports endozoochory. We also showed that non-mucilaginous seeds can be occasionally dispersed via endozoochory and are able to germinate. The results of our studies can explain the ways of plants distribution at a small, local scale as well as in long-distance dispersal, e.g., between islands or even continents.

Modular arrangements of sequence motifs determine the functional diversity of KDM proteins

2020 ◽  
Author(s):  
Zerong Wang ◽  
Dongyang Liu ◽  
Baofang Xu ◽  
Ruixia Tian ◽  
Yongchun Zuo
Keyword(s):  
Vital Role ◽  
Sequence Motifs ◽  
Chromatin Dynamics ◽  
Regulatory Motifs ◽  
Demethylase Activity ◽  
Functional Features ◽  
Catalytic Motif ◽  
Functional Mechanisms ◽  
Deep Exploration ◽  
First Time

Abstract Histone lysine demethylases (KDMs) play a vital role in regulating chromatin dynamics and transcription. KDM proteins are given modular activities by its sequence motifs with obvious roles division, which endow the complex and diverse functions. In our review, according to functional features, we classify sequence motifs into four classes: catalytic motifs, targeting motifs, regulatory motifs and potential motifs. JmjC, as the main catalytic motif, combines to Fe2+ and α-ketoglutarate by residues H-D/E-H and S-N-N/Y-K-N/Y-T/S. Targeting motifs make catalytic motifs recognize specific methylated lysines, such as PHD that helps KDM5 to demethylate H3K4me3. Regulatory motifs consist of a functional network. For example, NLS, Ser-rich, TPR and JmjN motifs regulate the nuclear localization. And interactions through the CW-type-C4H2C2-SWIRM are necessary to the demethylase activity of KDM1B. Additionally, many conservative domains that have potential functions but no deep exploration are reviewed for the first time. These conservative domains are usually amino acid-rich regions, which have great research value. The arrangements of four types of sequence motifs generate that KDM proteins diversify toward modular activities and biological functions. Finally, we draw a blueprint of functional mechanisms to discuss the modular activity of KDMs.

Sign in / Sign up

Export Citation Format

Share Document