Oxygen causes an increase in the longitudinal relaxation rate of tissues through its T1-shortening effect owing to its paramagnetic properties. Due to such effects, MRI has been used to study oxygen-related signal intensity changes in various body parts including cerebrospinal fluid (CSF) space. Oxygen enhancement of CSF has been mainly studied using MRI sequences with relatively longer time resolution such as FLAIR, and T1 value calculation. In this study, fifteen healthy volunteers were scanned using fast advanced spin echo MRI sequence with and without inversion recovery pulse in order to dynamically track oxygen enhancement of CSF. We also focused on the differences of oxygen enhancement at sulcal and ventricular CSF. Our results revealed that CSF signal after administration of oxygen shows rapid signal increase in both sulcal CSF and ventricular CSF on both sequences, with statistically significant predominant increase in sulcal CSF compared with ventricular CSF. CSF is traditionally thought to mainly form from the choroid plexus in the ventricles and is absorbed at the arachnoid villi, however, it is also believed that cerebral arterioles contribute to the production and absorption of CSF, and controversy remains in terms of the precise mechanism. Our results demonstrated rapid oxygen enhancement in sulcal CSF, which may suggest inhaled oxygen may diffuse into sulcal CSF space rapidly probably due to the abundance of pial arterioles on the brain sulci.

Rationale and Objectives

To optimize visualization of lenticulostriate artery (LSA) by time-of-flight (TOF) magnetic resonance angiography (MRA) with slice-selective off-resonance sinc (SORS) saturation transfer contrast pulses and to compare capability of optimal TOF-MRA and flow-sensitive black-blood (FSBB) MRA to visualize the LSA at 3T.

Materials and Methods

This study was approved by the local ethics committee, and written informed consent was obtained from all the subjects. TOF-MRA was optimized in 20 subjects by comparing SORS pulses of different flip angles: 0, 400°, and 750°. Numbers of LSAs were counted. The optimal TOF-MRA was compared to FSBB-MRA in 21 subjects. Images were evaluated by the numbers and length of visualized LSAs.

Results

LSAs were significantly more visualized in TOF-MRA with SORS pulses of 400° than others (P < .003). When the optimal TOF-MRA was compared to FSBB-MRA, the visualization of LSA using FSBB (mean branch numbers 11.1, 95% confidence interval (CI) 10.0–12.1; mean total length 236 mm, 95% CI 210–263 mm) was significantly better than using TOF (4.7, 95% CI 4.1–5.3; 78 mm, 95% CI 67–89 mm) for both numbers and length of the LSA (P < .0001).

Conclusions

LSA visualization was best with 400° SORS pulses for TOF-MRA but FSBB-MRA was better than TOF-MRA, which indicates its clinical potential to investigate the LSA on a 3T magnetic resonance imaging.

This paper examines the possibility of exploitation sea water in the agriculture of coastal deserts in Libya, some of which salt-tolerant plants (Halophyte), especially that used to feed animals, and convert marshes coastal useless life to nature reserves attract many kinds of migratory birds and marine lives after the cultivation of these marshes by type of plants, which grow in saltwater. In other words this paper will present a study of how to use the seawater as a renewable resource for agriculture in Libya and how this will contribute in sustainable development in this sprawling country. The advantage of this resource can be taken to fill up the gap of natural grassland and the growing demand for animal feed which has caused rising prices of livestock and meats, not to mention the tribal conflicts that occur because of the dispute over grasslands. The most significant reasons that force us to exploit the seawater are:(1) Lack of inventory of underground water in the coastal areas and overlapping with seawater in several areas. In contrast, Libya has the longest coastline on the Mediterranean with a length of more than 1,900 kilometers;(2) Fluctuation rate of the amount of rainfall, which has affected negatively on the natural grassland;(3) More than 90% of the country's population in the coastal areas, that causing a large drain of groundwater which already meager in this region, for this reason the government has worked to establish Artificial River project, which delivers water from the south to the northern areas to reduce this problem, and (4) Depletion and degradation of natural grassland is largely due to overgrazing.

Mercury exposure is associated with increased risk of cardiovascular disease and profound cardiotoxicity. However, the correlation between Hg(2+)-mediated toxicity and alteration in cardiac cytochrome P450s (Cyp) and their dependent arachidonic acid metabolites has never been investigated. Therefore, we investigated the effect of acute mercury toxicity on the expression of Cyp-epoxygenases and Cyp-ω-hydroxylases and their associated arachidonic acid metabolites in mice hearts. In addition, we examined the expression and activity of soluble epoxide hydrolase (sEH) as a key player in arachidonic acid metabolism pathway. Mercury toxicity was induced by a single intraperitoneal injection (IP) of 2.5 mg/kg of mercuric chloride (HgCl₂). Our results showed that mercury treatment caused a significant induction of the cardiac hypertrophy markers, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP); in addition to Cyp1a1, Cyp1b1, Cyp2b9, Cyp2b10, Cyp2b19, Cyp2c29, Cyp2c38, Cyp4a10, Cyp4a12, Cyp4a14, Cyp4f13, Cyp4f15, Cyp4f16 and Cyp4f18 gene expression. Moreover, Hg(2+) significantly increased sEH protein expression and activity levels in hearts of mercury-treated mice, with a consequent decrease in 14,15-, and 11,12-epoxyeicosatrienoic acids (EETs) levels. Whereas the formation of 14,15-, 11,12-, 8,9-dihydroxyeicosatrienoic acids (DHETs) was significantly increased. In conclusion, acute Hg(2+) toxicity modulates the expression of several Cyp and sEH enzymes with a consequent decrease in the cardioprotective EETs which could represent a novel mechanism by which mercury causes progressive cardiotoxicity. Furthermore, inhibiting sEH might represent a novel therapeutic approach to prevent Hg(2+)-induced hypertrophy.

The electrical and dielectric properties of the synthesized 2-(antipyrin-4-ylhydrazono)-2-(4-nitrophenyl)acetonitrile (AHNA) have been studied. The direct and alternating current (DC and AC) conductivities and complex dielectric constant were investigated in temperature range 303–403 K. The AC conductivity and dielectric properties of AHNA were investigated over frequency range 100 Hz–5 MHz. From DC and AC measurements, electrical conduction is found to be a thermally activated process. The frequency-dependent AC conductivity obeys Jonscher's universal power law in which the frequency exponent decreases with increasing temperature. The correlated barrier hopping (CBH) is the predominant model for describing the charge carrier transport in which the electrical parameters are evaluated. The activation energy is found to decrease with increasing frequency. The behaviors of dielectric and dielectric loss are discussed in terms of a polarization mechanism. The dielectric loss shows frequency power law from which the maximum barrier height is determined as 0.19 eV in terms of the Guintini model.

Several new pyridine derivatives were prepared via reacting the enaminoketones 1a-d with active hydrogen reagents. Reaction of the enaminoketones 1a-c with 4-acetyl-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one 2a yielded the pyridines 3a-c. Condensation of the enaminonitrile 1d with 2b-d or 3-(1,5-dimethyl-3-oxo-2-phenyl-2,3- dihydro-1H-pyrazol-4-yl)-3-oxopropanenitrile 8 give the pyridine derivatives 6a-c and 10 respectivly. Also, (E)-3- (3-(dimethylamino)acryloyl)-2H-chromen-2-one 1a reacted with active methylenes in diethyl 3-oxopentanedioate 12 and 4-methyl-6-oxo-2-thioxo-1,2,5,6-tetrahydropyridine-3-carbonitrile 15 to afford the pyridine derivatives 14 and 16 respectively.