5,288 research outputs found
Petroleum hydrocarbon assessment in the wastewaters of petrochemical special economic zone and sediment benchmark calculation of the coastal area - northwest of the Persian Gulf
Petrochemical industries can potentially impact the environment due to their activities and products. This case study has considered adverse effects of petrochemical industries that are located inside the PETZONE with respect to the presence of polycyclic aromatic hydrocarbons and total petroleum hydrocarbon in wastewater effluents. The average concentrations of ∑PAHs group I and II were lower than the guideline values, thus the effluents of the study area can be considered unpolluted. Also, the average concentration of TPH was lower than the guideline value at all almost stations except the effluent outlets of the Razi and Imam Khomeini petrochemical (BI-PC) companies which are proximal to Khowr-e Musa Bay. Thus, they may have an adverse impact on the aquatic ecosystem of the Bay. Therefore, the concentration of TPH was monitored in the sediments of the Bay (around the PETZONE coastal area) which was relatively moderate compared in the study area. Also, the sum of Chronic Potency Ratio of PAHs in sediments showed that the chronic benchmark was not more than the guideline at all stations (it is exceeded when the sum exceeds 1.0) except in the vicinity of the Aromatic effluent outlet of BI-PC. Thus, the chronic benchmark at this station indicates that it has the potential to cause a chronic effect on sediment-residence organisms like crabs, clams and worms. Moreover, PAHs concentration level in this station approached the NOAA sediment quality guideline value (ERL) of 4000 (ng/g dry weight)
Intranasal administration of endometrial mesenchymal stem cells as a suitable approach for Parkinson�s disease therapy
This study aimed to investigate the therapeutic effects of intranasal administration of human endometrium-derived stem cells (HEDSCs) in the mouse model of Parkinson�s disease (PD). Thirty days after intrastriatal injection of 6-OHDA, HEDSCs were administrated intranasally in three doses (104, 5 � 104 and 105 cells µl�1). During 120 days after stem cell administration, behavioral tests were examined. Then the mice were sacrificed and the fresh section of the substantia nigra pars compacta (SNpc) was used for detection of HEDSCs-GFP labeled by fluorescence microscopy method. In addition, immunohistochemistry was used to assay GFP, human neural Nestin, and tyrosine hydroxylase (TH) markers in the fixed brain tissue at the SNpc. Our data revealed that behavioral parameters were significantly improved after cell therapy. Fluorescence microscopy assay in fresh tissue and GFP analysis in fixed tissue were showed that the HEDSCs-GFP labeled migrated to SNpc. The data from immunohistochemistry revealed that the Nestin as a differential neuronal biomarker was expressed in SNpc. Also, TH as a dopaminergic neuron marker significantly increased after HEDSCs therapy in an optimized dose 5 � 104 cells µl�1. Our results suggest that intranasal administration of HEDSCs improve the PD symptoms in the mouse model of PD dose-dependent manner as a noninvasive method. © 2019, Springer Nature B.V
Discovery of Five New Pulsars in Archival Data
Reprocessing of the Parkes Multibeam Pulsar Survey has resulted in the
discovery of five previously unknown pulsars and several as-yet-unconfirmed
candidates. PSR J0922-52 has a period of 9.68 ms and a DM of 122.4 pc cm^-3.
PSR J1147-66 has a period of 3.72 ms and a DM of 133.8 pc cm^-3. PSR J1227-6208
has a period of 34.53 ms, a DM of 362.6 pc cm^-3, is in a 6.7 day binary orbit,
and was independently detected in an ongoing high-resolution Parkes survey by
Thornton et al. and also in independent processing by Einstein@Home volunteers.
PSR J1546-59 has a period of 7.80 ms and a DM of 168.3 pc cm^-3. PSR J1725-3853
is an isolated 4.79-ms pulsar with a DM of 158.2 pc cm^-3. These pulsars were
likely missed in earlier processing efforts due to their high DMs and short
periods and the large number of candidates that needed to be looked through.
These discoveries suggest that further pulsars are awaiting discovery in the
multibeam survey data.Comment: 12 pages, 2 figures, 2 tables, accepted to Ap
Human Arm simulation for interactive constrained environment design
During the conceptual and prototype design stage of an industrial product, it
is crucial to take assembly/disassembly and maintenance operations in advance.
A well-designed system should enable relatively easy access of operating
manipulators in the constrained environment and reduce musculoskeletal disorder
risks for those manual handling operations. Trajectory planning comes up as an
important issue for those assembly and maintenance operations under a
constrained environment, since it determines the accessibility and the other
ergonomics issues, such as muscle effort and its related fatigue. In this
paper, a customer-oriented interactive approach is proposed to partially solve
ergonomic related issues encountered during the design stage under a
constrained system for the operator's convenience. Based on a single objective
optimization method, trajectory planning for different operators could be
generated automatically. Meanwhile, a motion capture based method assists the
operator to guide the trajectory planning interactively when either a local
minimum is encountered within the single objective optimization or the operator
prefers guiding the virtual human manually. Besides that, a physical engine is
integrated into this approach to provide physically realistic simulation in
real time manner, so that collision free path and related dynamic information
could be computed to determine further muscle fatigue and accessibility of a
product designComment: International Journal on Interactive Design and Manufacturing
(IJIDeM) (2012) 1-12. arXiv admin note: substantial text overlap with
arXiv:1012.432
Relation of amniotic fluid C-peptide and insulin level and neonatal macrosomia
Background: Fetal hyperinsulinemia correlated with large birth weight and impaired glucose tolerance test and obesity in second decades of life. In this study we compared the correlation between fetal insulin production (as estimated by amniotic fluid (AF) C-peptide concentration) and AF insulin with macrosomia (as estimated by neonatal birth weight >4000 gr). Methods: Thirty eight neonates were studied. Ten infants were macrosom and 28 were normal (birth weight < 4000 gr). Amniontic fluid C-peptide and insulin concentration and mother and fetal blood C-peptide and insulin were measured during delivery with radioimmunoassay and mother and fetal glucose were measured at the same time and correlated with neonatal macrosomia within first hour of birth. Results: There was a significant correlation between infant serum C-peptide level and macrosomia. Amniotic fluid insulin level was higher in the macrosom infants but this correlation was not significant. AF C-peptide was higher in the macrosom group. Also there was a significant correlation between maternal serum C-peptide and macrosomia. Infant and mother serum insulin was higher in the macrosom group. Conclusion: Our results suggest that fetal insulin (as estimated by AF C- peptide) and mother insulin and C- peptide production, can influence fetal weight and induce fetal macrosomia
A Period of Controlled Elevation of IOP (CEI) Produces the Specific Gene Expression Responses and Focal Injury Pattern of Experimental Rat Glaucoma
PURPOSE: We determine if several hours of controlled elevation of IOP (CEI) will produce the optic nerve head (ONH) gene expression changes and optic nerve (ON) damage pattern associated with early experimental glaucoma in rats.
METHODS: The anterior chambers of anesthetized rats were cannulated and connected to a reservoir to elevate IOP. Physiologic parameters were monitored. Following CEI at various recovery times, ON cross-sections were graded for axonal injury. Anterior ONHs were collected at 0 hours to 10 days following CEI and RNA extracted for quantitative PCR measurement of selected messages. The functional impact of CEI was assessed by electroretinography (ERG).
RESULTS: During CEI, mean arterial pressure (99 ± 6 mm Hg) and other physiologic parameters remained stable. An 8-hour CEI at 60 mm Hg produced significant focal axonal degeneration 10 days after exposure, with superior lesions in 83% of ON. Message analysis in CEI ONH demonstrated expression responses previously identified in minimally injured ONH following chronic IOP elevation, as well as their sequential patterns. Anesthesia with cannulation at 20 mm Hg did not alter these message levels. Electroretinographic A- and B-waves, following a significant reduction at 2 days after CEI, were fully recovered at 2 weeks, while peak scotopic threshold response (pSTR) remained mildly but significantly depressed.
CONCLUSIONS: A single CEI reproduces ONH message changes and patterns of ON injury previously observed with chronic IOP elevation. Controlled elevation of IOP can allow detailed determination of ONH cellular and functional responses to an injurious IOP insult and provide a platform for developing future therapeutic interventions
Evaluation and optimization of chitosan derivatives-based gene delivery system via kidney epithelial cells
Purpose: Non-viral vectors have been widely proposed as safer alternatives to viral vectors, and cationic polymers have gained increasing attention because they can form self-assembly with DNA. Chitosan is also considered to be a good candidate for gene delivery systems, since it is already known as a biocompatible, biodegradable, and low toxic material with high cationic potential. However, low solubility and transfection efficiency need to be overcome prior to clinical trial. In this work, we focus on alkyl modified chitosan which might be useful in DNA condensing and efficient gene delivery. Methods: N, N- Diethyl N- Methyl (DEMC) and N- Triethyl Chitosan (TEC) were synthesized from chitosan polymer. In order to optimize the polymers for gene delivery, we used FITC-dextran (FD). Then the optimized polymer concentrations were used for gene delivery. Fluorescent microscope was used, in order to evaluate the polymers’ efficiency for gene delivery to human embryonic kidney epithelial cells (HEK 293T). Results: This modification increased chitosan’s positive charge, thus these chitosan derivatives spontaneously formed complexes with FD, green fluorescence protein plasmid DNA (pEGFP), red fluorescence protein plasmid DNA (pJred) and fluorescent labeled miRNA. Results gained from fluorescent microscope showed that TEC and DEMC were able to transfer FD, DNA and miRNA (micro RNA) to HEK cell line. Conclusion: We conclude that these chitosan derivatives present suitable characteristics to be used as non-viral gene delivery vectors to epithelial cells
The relationship between anti-mullerian hormone in women receiving fertility assessments and age at menopause in subfertile women: evidence from large population studies
<p>Context: Anti-Müllerian hormone (AMH) concentration reflects ovarian aging and is argued to be a useful predictor of age at menopause (AMP). It is hypothesized that AMH falling below a critical threshold corresponds to follicle depletion, which results in menopause. With this threshold, theoretical predictions of AMP can be made. Comparisons of such predictions with observed AMP from population studies support the role for AMH as a forecaster of menopause.</p>
<p>Objective: The objective of the study was to investigate whether previous relationships between AMH and AMP are valid using a much larger data set.</p>
<p>Setting: AMH was measured in 27 563 women attending fertility clinics.</p>
<p>Study Design: From these data a model of age-related AMH change was constructed using a robust regression analysis. Data on AMP from subfertile women were obtained from the population-based Prospect-European Prospective Investigation into Cancer and Nutrition (Prospect-EPIC) cohort (n = 2249). By constructing a probability distribution of age at which AMH falls below a critical threshold and fitting this to Prospect-EPIC menopausal age data using maximum likelihood, such a threshold was estimated.</p>
<p>Main Outcome: The main outcome was conformity between observed and predicted AMP.</p>
<p>Results: To get a distribution of AMH-predicted AMP that fit the Prospect-EPIC data, we found the critical AMH threshold should vary among women in such a way that women with low age-specific AMH would have lower thresholds, whereas women with high age-specific AMH would have higher thresholds (mean 0.075 ng/mL; interquartile range 0.038–0.15 ng/mL). Such a varying AMH threshold for menopause is a novel and biologically plausible finding. AMH became undetectable (<0.2 ng/mL) approximately 5 years before the occurrence of menopause, in line with a previous report.</p>
<p>Conclusions: The conformity of the observed and predicted distributions of AMP supports the hypothesis that declining population averages of AMH are associated with menopause, making AMH an excellent candidate biomarker for AMP prediction. Further research will help establish the accuracy of AMH levels to predict AMP within individuals.</p>
Fibers and global geometry of functions
Since the seminal work of Ambrosetti and Prodi, the study of global folds was
enriched by geometric concepts and extensions accomodating new examples. We
present the advantages of considering fibers, a construction dating to Berger
and Podolak's view of the original theorem. A description of folds in terms of
properties of fibers gives new perspective to the usual hypotheses in the
subject. The text is intended as a guide, outlining arguments and stating
results which will be detailed elsewhere
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