172 research outputs found
Purification and Characterization of Recombinant Darbepoetin Alfa from Leishmania tarentolae
Darbepoetin alfa is a biopharmaceutical glycoprotein that stimulates erythropoiesis and is used to treat anemia, which associated with renal failure and cancer chemotherapy. We herein describe the structural characterization of recombinant darbepoetin alfa produced by Leishmania tarentolae T7-TR host. The DNA expression cassette was integrated into the L. tarentolae genome through homologous recombination. Transformed clones were selected by antibiotic resistance, diagnostic PCRs, and protein expression analysis. The structure of recombinant darbepoetin alfa was analyzed by isoelectric focusing, ultraviolet–visible spectrum, and circular dichroism (CD) spectroscopy. Expression analysis showed the presence of a protein band at 40 kDa, and its expression level was 51.2 mg/ml of culture medium. Darbepoetin alfa have 5 isoforms with varying degree of sialylation. The UV absorption and CD spectra were analogous to original drug (Aranesp), which confirmed that the produced protein was darbepoetin alfa. Potency test results revealed that the purified protein was biologically active. In brief, the structural and biological characteristics of expressed darbepoetin alfa were very similar to Aranesp which has been normally expressed in CHO. Our data also suggest that produced protein has potential to be developed for clinical use. © 2016, Springer Science+Business Media New York
Solvent-free Oxidation of Alcohols and Mild Catalytic Deprotection of Silyl Ethers with Poly(N,N’-dibromo-N-ethyl-benzene-1,3-disulphonamide) and N,N,N’,N’-tetrabromobenzene-1,3-disulphonamide
Poly(N,N’-dibromo-N-ethyl-benzene-1,3-disulphonamide) (PBBS) and N,N,N’,N’-tetrabromobenzene- 1,3-disulphonamide (TBBDA) can be used for solvent-free oxidation of primary and secondary alcohols to the corresponding carbonyl compounds without over-oxidation, and efficient catalytic deprotection of various silyl ethers to hydroxyl groups in aprotic organic solvents under ambient conditions.KEYWORDS: Solvent-free oxidation, alcohols, catalytic deprotection, silyl ethers, PBBS, TBBDA
Intestinal malrotations: a review and report of thirty cases
Intestinal malrotation is a developmental anomaly affecting the position and
peritoneal attachments of the small and large bowels during organogenesis in
foetal life. It has been defined as absent or incomplete rotation and fixation of
the embryonic gut around the superior mesenteric artery. In the present paper,
we review the definition, history, embryology/aetiology, epidemiology, symptoms
and signs, diagnosis and treatment of intestinal malformations. Moreover,
we report the records of 30 cases of malrotation admitted to our department
over a period of five years. The final intraoperative diagnosis of the cases presented
was 53.3% pure malrotation, 33.3% malrotation with mid-gut volvulus,
6.7% malrotation with duodenal atresia, 3.3% malrotation with Meckel’s diverticulum
and duodenal atresia, and 3.3% malrotation and biliary atresia. Preoperative
imaging studies were performed for 27 cases and surgical management
was successfully conducted without any mortality among the cases studied. This
article provides an overview of basic and clinical aspects of intestinal malrotation.
In addition, the signs and symptoms, imaging findings, and final intraoperative
diagnoses presented by the subjects reported on are of potential use and
clinical interest
Highly Efficient Formylation of Alcohols, Thiols and Aniline Derivatives by a Heterogeneous (HCOOH/SiO2) System under Microwave Irradiation and Solvent-free Conditions
A simple, rapid and efficient microwave-assisted procedure for the formylation of aniline derivatives and alcohols, using a heterogeneous (HCOOH/SiO2) system under solvent-free conditions is reported. The method is applied to a set of amines, alcohols and thiols and short reaction times (<10 min) with high yields are reported. This protocol introduces a practical and viable green technology of solvent-free and catalyst-free reactions.Keywords: Alcohols, anilines, SiO2, HCOOH, microwave irradiation, solvent-free condition
Comparison of the Push-Out Bond Strength of 5th, 6th, 7th and 8th Generation Bonding Agents to Intracanal Dentin of Primary Anterior Teeth
Background and Objective: Due to the importance of primary anterior teeth in chewing, pronunciation of words, self-confidence, facial appearance of children, efforts to preserve these teeth continue. The aim of the present study was to evaluate the push-out bond strength of 5th, 6th, 7th, and 8th generation bonding agents to intracanal dentin of primary anterior teeth which are reconstructed with the composite posts.
Methods: The present experimental in vitro study was conducted on 60 extracted primary anterior teeth with at least two-thirds of the root length remaining. The teeth were randomly divided into five groups: 5th generation (3M Adper single bond 2 Adhesive-USA), 6th generation (clearfil SE bond, Japan), 7th generation (kerr-optibond all in one Adhesive-Italy), and 8th generation total-etch and 8th generation self-etch (GC-G permio bond-Japan) bonding agents. After root canal preparation, prepared canals were filled with Metapex. The coronal 3mm of the canals was etched and impregnated with the dentin bonding agents. Then, they were restored with composite. The push-out test was performed to evaluate the bond strength of adhesives. Accordingly, by a light microscope the failure modes were determined.
Findings: The mean bond strength of 5th, 6th, 7th, and 8th generation (self-etch, total-etch) bonding agents was 4.36±2.15, 3.88±1.55, 4.29±2.02, 12.84±3.62, and 7.77±3.81 MPa, respectively. The push-out bond strength of the 8th generation bonding agent using both self-etch (p=0.000) and total-etch techniques was higher than the 5th, 6th, and 7th generation bonding agents (p=0.032, 0.01, 0.027, respectively). No significant difference was found between the bond strength of the 5th, 6th, and 7th generation bonding agents.
Conclusion: The push-out bond strength of the 8th generation bonding system was higher than the other groups. Therefore, the 8th generation bonding agents can be used to bond composite posts to intracanal dentin of primary anterior teeth. Also, self-etch (8th generation) has higher bond strength compared to the total-etch technique
Analgesic Effects of the Aqueous Lemon Verbena Extract in Rats
Lemon verbena (vervain, LV) is used in traditional folk medicine as a remedy against asthma,
spasms, cold, fever, pain of different genesis, insomnia, etc., but its effects have not been
examined experimentally. We studied effects of an aqueous extract of leafs of this plant on
the parameters of nociception-related tests, tail-flick, and writhing ones. The first aqueous
extract of LV leafs was prepared and dried. Wistar rats were randomly divided into seven experimental groups, which received i.p. injections of saline (control), LV extract (10, 100, 500,
and 1000 mg of dry substance per 1 kg of the body mass), morphine, and 1000 mg/kg of the
LV extract + naloxone. Injections of 500 and 1000 mg/kg of the extract significantly increased
the tail-flick latency, as compared to that in the control group (P < 0.001). The number of
writhings per one hour decreased after injections of the extract (100-1000 mg/kg). The maximum analgesic effects of the extract were comparable with those of morphine (10 mg/kg).
Naloxone completely abolished the effect of the LV extract in the tail-flick test and partly
suppressed such action in the writhing test. Thus, our experiments demonstrated noticeable
anti-nociceptive effects of the aqueous LV extract; possibilities for application of this extract
or its derivatives in pain management should be examined.Лимонна вербена (ЛВ) використовується в традиційній народній медицині як засіб проти астми, спазмів, застуди, лихоманки, болю різного походження, безсоння і т. п., проте її ефекти
не досліджувались експериментально. Ми вивчали дію водного
екстракту листя цієї рослини на параметри тестів, пов’язаних
із ноцицепцією, – тесту відсмикування хвоста та тесту «кислотних корчів». Готували перший водний екстракт із листя ЛВ
та дегітратували його. Досліди були проведені на семи експериментальних групах щурів лінії Вістар; тварини цих груп
отримували внутрішньоочеревинні ін’єкції фізіологічного розчину (контроль), ЛВ-екстракту в чотирьох дозах (10, 100, 500
та 1000 мг сухої речовини на 1 кг маси тіла), морфіну та екстракту ЛВ (1000 мг/кг) із попередньою ін’єкцією налоксону.
Ін’єкції екстракту в дозах 500 та 1000 мг/кг призводили до
істотного збільшення латентного періоду реакції відсмикування хвоста порівняно з аналогічним показником у контролі
(P < 0.001). Кількість «корчів» у відповідному тесті протягом
1 год істотно зменшувалася після ін’єкцій екстракту в дозах
від 100 до 1000 мг/кг. Максимальні аналгетичні ефекти були
близькими до таких після ін’єкцій морфіну (10 мг/кг). Налоксон повністю усував ефекти екстракту ЛВ у тесті відсмикування хвоста, але лише частково пригнічував відповідну дію
в тесті «корчів». Отже, результати наших експериментів показали, що водний екстракт листя ЛВ має відчутну антиноцицептивну дію; можливості застосування цього екстракту або
його похідних у контролі болю мають бути досліджені в подальшому
Fabrication of Pd NPs on pectin-modified Fe3O4 NPs: A magnetically retrievable nanocatalyst for efficient C-C and C-N cross coupling reactions and an investigation of its cardiovascular protective effects
The present report represents the synthesis of a novel Pd NPs immobilized over a natural polysaccharide (pectin) coated Fe3O4 magnetic nanocomposite material (Fe3O4@pectin/Pd) for investigating the cardiovascular protective effects. The biomolecular functionalization not only stabilizes the ferrite nanoparticles from agglomeration but also provides an environment for the biogenic reduction of Pd2+ ions. This protocol is a promising breakthrough for the synthesis of a quasi-heterogeneous catalyst, a bridge between heterogeneous and homogeneous medium. The structure, morphology and physicochemical properties of the material were characterized utilizing various analytical techniques like FT-IR FE-SEM, TEM, VSM, EDX-elemental mapping, ICP, EDX and XPS. The catalyst showed excellent reactivity in C-C and C-N cross coupling reactions via Suzuki and Buchwald-Hartwig reactions respectively. An array of different biphenyls and aryl amines were then procured by reactions of various aryl halides with phenyl boronic acid or secondary amines over the catalyst affording good to excellent yields. The catalyst was easily recoverable using an external magnet and thereafter recycled for several trials with insignificant palladium leaching or loss in catalytic performance. To investigate the cardiovascular protective activities of catalyst, the MTT assay was done on Human Aortic Endothelial Cells (HAEC), Human Coronary Artery Endothelial Cells (HCAEC), and Human Pulmonary Artery Endothelial Cells (HPAEC) cell lines. Nanocatalyst-treated cell cutlers significantly (p <= 0.01) decreased the caspase-3 activity, and DNA fragmentation. It raised the cell viability and mitochondrial membrane potential in the high concentration of Mitoxantrone-treated HAEC, HCAEC, and HPAEC cells. According to the above findings, nanocatalyst can be administrated as a cardiovascular protective drug for the treatment of cardiovascular diseases after approving in the clinical trial studies in humans. (C) 2020 Published by Elsevier B.V
Palladium nanoparticles supported on fluorine-doped tin oxide as an efficient heterogeneous catalyst for Suzuki coupling and 4-nitrophenol reduction
Immobilization of palladium nanoparticles onto the fluorine-doped tin oxide (FTO) as support Pd/FTO, resulted in a highly active heterogeneous catalyst for Suzuki-Miyaura cross-coupling reactions and 4-nitrophenol reduction. The Pd/FTO catalyst has been synthesized by immobilization of palladium nanoparticles onto FTO via a simple impregnation method. ICP-MS analysis confirmed that there is 0.11 mmol/g of palladium was loaded successfully on FTO support. The crystallinity, morphologies, compositions and surface properties of Pd/FTO were fully characterized by various techniques. It was further examined for its catalytic activity and robustness in Suzuki coupling reaction with different aryl halides and solvents. The yields obtained from Suzuki coupling reactions were basically over 80%. The prepared catalyst was also tested on mild reaction such as reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). Pd/FTO catalyst exhibited high catalytic activity towards 4-NP reduction with a rate constant of 1.776 min(-1) and turnover frequency (TOF) value of 29.1 hr(-1). The findings revealed that Pd/FTO also maintained its high stability for five consecutive runs in Suzuki reactions and 4-NP reductions. The catalyst showed excellent catalytic activities by using a small amount of Pd/FTO for the Suzuki coupling reaction and 4-NP reduction
Dynamical complexity of short and noisy time series: Compression-Complexity vs. Shannon entropy
Shannon entropy has been extensively used for characteriz-
ing complexity of time series arising from chaotic dynamical systems and stochastic processes such as Markov chains. However, for short and noisy time series, Shannon entropy performs poorly. Complexity measures which are based on lossless compression algorithms are a good substitute in such scenarios. We evaluate the performance of
two such Compression-Complexity Measures namely Lempel-Ziv complexity(LZ)andEffort-To-Compress(
ETC)onshorttimeseriesfrom chaoticdynamicalsystemsinthepresenceofnoise.Both
LZ and ETC outperform Shannon entropy (H) in accurately characterizing the dynamical complexity of such systems. For very short binary sequences
(which arise in neuroscience applications),
ETC has higher number of distinct complexity values than
LZ and H, thus enabling a finer resolution. For two-state ergodic Markov chains, we empirically show that ETC
converges to a steady state value faster than LZ.
Compression-Complexity measures
are promising for applications which involve short
and noisy time series
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