110 research outputs found

    4,4′,6,6′-Tetra-tert-butyl-2,2′-[butane-1,4-diylbis(nitrilo­methanylyl­idene)]diphenol

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    The title compound, C34H52N2O2, is centrosymmetric, the mid-point of the central C—C bond being located on an inversion centre. Intra­molecular O—H⋯N and weak C—H⋯O hydrogen bonds are observed, but no significant inter­molecular inter­actions occur in the crystal structure

    Effect of different operating modes and biomass concentrations on the recovery of recombinant hepatitis B core antigen from thermal-treated unclarified Escherichia coli feedstock

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    Expanded bed adsorption chromatography (EBAC) is a single pass operation that has been used as primary capture step in various protein purifications. The most common problem in EBAC is often associated with successful formation of a stable fluidized bed during the absorption stage, which is critically dependent on parameters such as liquid velocity, bed height, particle (adsorbent) size and density as well as design of column and type of flow distributor. In this study, residence time distribution (RTD) test using acetone as non-binding tracer acetone was performed to evaluate liquid dispersion characteristics of the EBAC system. A high B(o) number was obtained indicating the liquid dispersion in the system employed is very minimal and the liquid flow within the bed was close to plug flow, which mimics a packed bed chromatography system. Evaluation on the effect of flow velocities and bed height on the performance of Streamline DEAE using feedstock containing heat-treated crude Escherichia coli homogenate of different biomass concentrations was carried out in this study. The advantages and disadvantages as well as the problems encountered during recovery of HBcAg with aforementioned parameters are also discussed in this paper

    Bis(μ-hexa­deca­noato-κ2 O:O)bis­[(2,2′-bipyridine-κ2 N,N′)(hexa­deca­noato-κO)copper(II)] methanol disolvate

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    The asymmetric unit of the title compound, [Cu2(C16H31O2)4(C10H8N2)2]·2CH3OH, contains one half-mol­ecule of the metal complex solvated by a methanol mol­ecule. In the complex, two of the metal atoms are doubly bridged by two monodentate bridging hexa­deca­noate ligands around a center of inversion. The square-pyramidal geometry around each CuII ion is completed by a terminal hexa­deca­noate O atom and two N atoms from a 2,2′-bipyridine ligand. The alkyl chains of the carboxyl­ate ligands are arranged in a parallel manner with an all-trans conformation. In the crystal, a π–π inter­action formed by the bipyridine rings [centroid–centroid separation = 3.7723 (17) Å] and inter­molecular C—H⋯O hydrogen bonds link the complex mol­ecules into infinite chains along the b axis. An O—H⋯O interaction between the methanol solvate and one of the carboxylate O atoms is also observed

    2,2′-[Nonane-1,9-diylbis(nitrilo­methyl­idyne)]diphenol

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    In the title Schiff base compound, C23H30N2O2, the complete mol­ecule is generated by crystallographic twofold symmetry, with one C atom lying on the rotation axis. The nonane chain adopts a linear conformation and the hydr­oxy group forms an intra­molecular O—H⋯N hydrogen bond to the imine group

    Effect of promoter strength and signal sequence on the periplasmic expression of human interferon-α2b in Escherichia coli

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    Two plasmids, pFLAG-ATS and pET 26b(+), were studied for the periplasmic expression of recombinant human interferon-α2b (IFN-α2b) in Escherichia coli. The pFLAG-ATS contains ompA signal sequence and tac promoter while pET 26b(+) contains pelB signal sequence and T7lac promoter. It was observed that periplasmic expression of IFN-α2b from pET 26b(+) was around 3000 times higher than pFLAG-ATS. Difference in the expression level was attributed to the difference in the promoters and the signal sequences. In silico analysis of mRNA secondary structures were analyzed using Vienna RNA package and MFOLD. The resultssuggested that the increase of expression would mainly due to the difference in the translation initiation associated with secondary structure of mRNA transcribed by both plasmids

    Purification of rabbit polyclonal immunoglobulin G with ammonium sulphate precipitation and mixed-mode chromatography

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    Immunoglobulins G (IgG) against hepatitis B core antigen (HBcAg) was successfully purified using a purification scheme comprising ammonium sulphate precipitation and SepFast™ MM AH-1 column chromatography. Ammonium sulphate precipitation performed at 40% saturation was optimum in terms of the recovered polyclonal IgG concentration (7.8 mg/ml) and the removal of albumin (72%). The yield, purity and purification factor achieved from this simple purification method were 99%, 94% and 7.8, respectively. The IgG recovered from ammonium sulphate precipitation was subjected to SepFast™ MM AH-1 column chromatography and the purity of IgG was further increased to 98%, corresponding to a purification factor of 8.1. Protein aggregation was also reduced significantly in the purified IgG sample. Furthermore, the salt content in the purified sample was reduced by 75% and therefore the need of desalting final product was eliminated. Enzyme-linked immunosorbent assay (ELISA) showed that the antigenicity of anti-HBcAg IgG obtained after these purification processes was maintained

    Can Transcranial Electrical Stimulation Facilitate Post-stroke Cognitive Rehabilitation? A Systematic Review and Meta-Analysis

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    BackgroundNon-invasive brain stimulation methods have been widely utilized in research settings to manipulate and understand the functioning of the human brain. In the last two decades, transcranial electrical stimulation (tES) has opened new doors for treating impairments caused by various neurological disorders. However, tES studies have shown inconsistent results in post-stroke cognitive rehabilitation, and there is no consensus on the effectiveness of tES devices in improving cognitive skills after the onset of stroke.ObjectivesWe aim to systematically investigate the efficacy of tES in improving post-stroke global cognition, attention, working memory, executive functions, visual neglect, and verbal fluency. Furthermore, we aim to provide a pathway to an effective use of stimulation paradigms in future studies.MethodsPreferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines were followed. Randomized controlled trials (RCTs) were systematically searched in four different databases, including Medline, Embase, Pubmed, and PsychInfo. Studies utilizing any tES methods published in English were considered for inclusion. Standardized mean difference (SMD) for each cognitive domain was used as the primary outcome measure.ResultsThe meta-analysis includes 19 studies assessing at least one of the six cognitive domains. Five RCTs studying global cognition, three assessing visual neglect, five evaluating working memory, three assessing attention, and nine studies focusing on aphasia were included for meta-analysis. As informed by the quantitative analysis of the included studies, the results favor the efficacy of tES in acute improvement in aphasic deficits (SMD = 0.34, CI = 0.02–0.67, p = 0.04) and attention deficits (SMD = 0.59, CI = −0.05–1.22, p = 0.07), however, no improvement was observed in any other cognitive domains.ConclusionThe results favor the efficacy of tES in an improvement in aphasia and attentive deficits in stroke patients in acute, subacute, and chronic stages. However, the outcome of tES cannot be generalized across cognitive domains. The difference in the stimulation montages and parameters, diverse cognitive batteries, and variable number of training sessions may have contributed to the inconsistency in the outcome. We suggest that in future studies, experimental designs should be further refined, and standardized stimulation protocols should be utilized to better understand the therapeutic effect of stimulation

    The postmastectomy pain syndrome: an epidemiological study on the prevalence of chronic pain after surgery for breast cancer

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    The prevalence of the postmastectomy pain syndrome (PMPS) and its clinical characteristics was assessed in a group of patients who had undergone surgery for breast cancer at the Department of Surgery, Odense University Hospital, within the period of 1 May 2003 to 30 April 2004. The study included 258 patients and a reference group of 774 women. A questionnaire was mailed to the patients 1½ year after surgery and to the women in the reference group. The PMPS was defined as pain located in the area of the surgery or ipsilateral arm, present at least 4 days per week and with an average intensity of at least 3 on a numeric rating scale from 0 to 10. The prevalence of PMPS was found to be 23.9%. The odds ratio of developing PMPS was 2.88 (95% confidence interval 1.84–4.51). Significant risk factors were as follows: having undergone breast surgery earlier (OR 8.12), tumour located in the upper lateral quarter (OR 6.48) and young age (OR 1.04). This study shows that, although recent advances in the diagnostic and surgical procedures have reduced the frequency of the more invasive surgical procedures, there still is a considerable risk of developing PMPS after treatment of breast cancer

    Low levels of amyloid-beta and its transporters in neonatal rats with and without hydrocephalus

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    <p>Abstract</p> <p>Background</p> <p>Previous studies in aging animals have shown that amyloid-beta protein (Aβ) accumulates and its transporters, low-density lipoprotein receptor-related protein-1 (LRP-1) and the receptor for advanced glycation end products (RAGE) are impaired during hydrocephalus. Furthermore, correlations between astrocytes and Aβ have been found in human cases of normal pressure hydrocephalus (NPH) and Alzheimer's disease (AD). Because hydrocephalus occurs frequently in children, we evaluated the expression of Aβ and its transporters and reactive astrocytosis in animals with neonatal hydrocephalus.</p> <p>Methods</p> <p>Hydrocephalus was induced in neonatal rats by intracisternal kaolin injections on post-natal day one, and severe ventriculomegaly developed over a three week period. MRI was performed on post-kaolin days 10 and 21 to document ventriculomegaly. Animals were sacrificed on post-kaolin day 21. For an age-related comparison, tissue was used from previous studies when hydrocephalus was induced in a group of adult animals at either 6 months or 12 months of age. Tissue was processed for immunohistochemistry to visualize LRP-1, RAGE, Aβ, and glial fibrillary acidic protein (GFAP) and with quantitative real time reverse transcriptase polymerase chain reaction (qRT-PCR) to quantify expression of LRP-1, RAGE, and GFAP.</p> <p>Results</p> <p>When 21-day post-kaolin neonatal hydrocephalic animals were compared to adult (6–12 month old) hydrocephalic animals, immunohistochemistry demonstrated levels of Aβ, RAGE, and LRP-1 that were substantially lower in the younger animals; in contrast, GFAP levels were elevated in both young and old hydrocephalic animals. When the neonatal hydrocephalic animals were compared to age-matched controls, qRT-PCR demonstrated no significant changes in Aβ, LRP-1 and RAGE. However, immunohistochemistry showed very small increases or decreases in individual proteins. Furthermore, qRT-PCR indicated statistically significant increases in GFAP.</p> <p>Conclusion</p> <p>Neonatal rats with and without hydrocephalus had low expression of Aβ and its transporters when compared to adult rats with hydrocephalus. No statistical differences were observed in Aβ and its transporters between the control and hydrocephalic neonatal animals.</p

    Genetic Association for Renal Traits among Participants of African Ancestry Reveals New Loci for Renal Function

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    Chronic kidney disease (CKD) is an increasing global public health concern, particularly among populations of African ancestry. We performed an interrogation of known renal loci, genome-wide association (GWA), and IBC candidate-gene SNP association analyses in African Americans from the CARe Renal Consortium. In up to 8,110 participants, we performed meta-analyses of GWA and IBC array data for estimated glomerular filtration rate (eGFR), CKD (eGFR <60 mL/min/1.73 m2), urinary albumin-to-creatinine ratio (UACR), and microalbuminuria (UACR >30 mg/g) and interrogated the 250 kb flanking region around 24 SNPs previously identified in European Ancestry renal GWAS analyses. Findings were replicated in up to 4,358 African Americans. To assess function, individually identified genes were knocked down in zebrafish embryos by morpholino antisense oligonucleotides. Expression of kidney-specific genes was assessed by in situ hybridization, and glomerular filtration was evaluated by dextran clearance. Overall, 23 of 24 previously identified SNPs had direction-consistent associations with eGFR in African Americans, 2 of which achieved nominal significance (UMOD, PIP5K1B). Interrogation of the flanking regions uncovered 24 new index SNPs in African Americans, 12 of which were replicated (UMOD, ANXA9, GCKR, TFDP2, DAB2, VEGFA, ATXN2, GATM, SLC22A2, TMEM60, SLC6A13, and BCAS3). In addition, we identified 3 suggestive loci at DOK6 (p-value = 5.3×10−7) and FNDC1 (p-value = 3.0×10−7) for UACR, and KCNQ1 with eGFR (p = 3.6×10−6). Morpholino knockdown of kcnq1 in the zebrafish resulted in abnormal kidney development and filtration capacity. We identified several SNPs in association with eGFR in African Ancestry individuals, as well as 3 suggestive loci for UACR and eGFR. Functional genetic studies support a role for kcnq1 in glomerular development in zebrafish
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