Slow light nanocoatings for ultrashort pulse compression.

Transparent materials do not absorb light but have profound influence on the phase evolution of transmitted radiation. One consequence is chromatic dispersion, i.e., light of different frequencies travels at different velocities, causing ultrashort laser pulses to elongate in time while propagating. Here we experimentally demonstrate ultrathin nanostructured coatings that resolve this challenge: we tailor the dispersion of silicon nanopillar arrays such that they temporally reshape pulses upon transmission using slow light effects and act as ultrashort laser pulse compressors. The coatings induce anomalous group delay dispersion in the visible to near-infrared spectral region around 800 nm wavelength over an 80 nm bandwidth. We characterize the arrays' performance in the spectral domain via white light interferometry and directly demonstrate the temporal compression of femtosecond laser pulses. Applying these coatings to conventional optics renders them ultrashort pulse compatible and suitable for a wide range of applications.

Carotid intima media thickness and other cardiovascular risk factors in children with congenital adrenal hyperplasia.

PURPOSE: Patients with congenital adrenal hyperplasia (CAH) are at increased risk for cardiovascular disease due to many factors. The aim of this study is to investigate the presence of dyslipidemia, insulin resistance, and subclinical atherosclerosis as indicated by carotid intima media thickness in children with congenital adrenal hyperplasia. METHODS: Thirty-two children with congenital adrenal hyperplasia (3-17 years) were compared with 32 healthy controls. All underwent anthropometric evaluation, measurement of fasting lipids, glucose, insulin, oral glucose tolerance test (OGTT), homeostasis model assessment for insulin resistance (HOMA-IR), and carotid intima media thickness (CIMT). RESULTS: Fasting glucose, glucose at 30, 60, 90, and 120 min during OGTT were significantly higher in patients. HOMA-IR was also significantly higher in patients (p = 0.036). Patients had significantly higher CIMT (p = 0.003), and higher systolic blood pressure. (p = 0.04). No significant difference existed in lipid profile. Both systolic and diastolic blood pressures correlated with treatment duration (p = 0.002, p = 0.043, respectively). CONCLUSION: Children with CAH are at increased risk of insulin resistance, glucose intolerance, early atherosclerosis, and cardiovascular disease. Screening of these patients at an early age is recommended.

Ionization of some derivatives of benzamide, oxamide and malonamide in DMF-water mixture.

The ionization of six compounds of bis-phenolic amides was studied spectrophotochemically in DMF-water mixture. The compounds showed two pK(a) values in the range of 5.97-7.32 for pK(a(1)) and 7.61-8.44 for pK(a(2)). The obtained values of K(a) were normalized using the distribution diagrams of the different species and found to be in the range of 5.81-7.42 for pK(a(1)) and 7.48-8.27 for pK(a2).

Sexual dysfunction in Saudi depressed male patients.

INTRODUCTION Sexual dysfunction is common among depressed male patients; however, its causes are complex and multifactorial. The aim of this study is to identify risk factors for sexual dysfunction associated with depression. METHODS One hundred and twenty-five consecutive depressed male patients were interviewed at Jeddah Psychiatric Hospital. They were divided in to two groups, on the basis of whether they had sexual dysfunction or not. These two groups were then compared on a number of potential risk factors, using chi-square and odds ratio. RESULTS The majority of patients had not previously been asked about sexual dysfunction. Seventy-seven (62%) presented with sexual dysfunction and 48 (38%) without. Marital difficulties, hypertension, diabetes, severity of depression and tricyclic antidepressants were significant risk factors. No association was found with demographic origin, occupation, education or marital status. These results are similar in some aspects to those reported in western studies. CONCLUSIONS (a) The majority of doctors do not take a sexual history despite its high prevalence. (b) Physical illness and overall severity of depression were important risk factors.

Simple synthesis of condensed pyran containing compounds and their antimicrobial properties.

Reaction of various fused pyran compounds with formic acid was studied. Thus, refluxing 6-aminopyrano[2,3-c]pyrazole-5-carbonitriles 3 with formic acid afforded the corresponding 3-aryl-3-(5-hydroxy-3-methyl-1H-pyrazole-4-yl)propanoic acids 4. Whereas, reaction of formic acid with 2-amino-4H-1-benzopyran-3-carbonitriles 6 gave the corresponding quinoline-2,5(1H,6H)-diones 7. The study was also extended towards many spiro compounds possessing pyran residue. The antimicrobial properties of the prepared compounds was screened.

Synthetic approaches towards benzo[h]quinoline-3-carbonitriles.

2-Alkoxybenzo[h]quinoline-3-carbonitriles 2 were readily synthesized via Dimroth rearrangement of 2-amino-4-aryl-5,6-dihydro-4H-naphtho[1,2-b]pyran-3-carbonitriles 5 induced by ethanolic and methanolic KOH. Compounds 2 were also obtained by the reaction of 2-arylmethylidene-3,4-dihydro-1(2H)-naphthalenones 1 with malononitrile or of ylidenemalononitriles 4 with 1,2,3,4-tetrahydro-1-naphthalenone in ethanolic and methanolic KOH. The molluscicidal activity of the products towards Biomphalaria alexandrina snails was screened.

New 2 H-benz[g]indazoles of anticipated molluscicidal activity.

A facile synthetic approach towards the synthesis of 2-substituted carbamoyl (or thiocarbamoyl)-3-aryl-3,3a,4,5-tetrahydro-2 H-benz[g]indazoles 3a-r and their 2-acylating derivatives 4-6 was reported via the reaction of 2-unsubstituted-2 H-benz[g]indazoles 2 with isocyanates or their thio analogues, acid anhydrides and aliphatic or aromatic carboxylic acids. The molluscicidal activity of the products was screened.

Seventeen new 14- and 15-crown-formazans: their synthesis and evaluation in spectrophotometric determination of lithium.

A number of new crown-formazans with 14 and 15 membered rings have been synthesized, characterized and investigated as selective spectrophotometric chelating agents for lithium. The effect of sodium ion concentration on the background lithium signal was studied. A comparative study for the sensitivity of these new crown-formazans in spectrophotometric determinations was studied and compared with those reported previously. The three new 14- and 15-crown-formazans 4a-c containing the pyridyl N-oxide at the formazyl carbon showed the highest selectivity to lithium determination in the presence of sodium ion.

Evaluation of some new 14- and 15-crown-formazans as carriers in cesium ion selective electrodes.

A number of new crown-formazans with 14 and 15 membered rings have been investigated as selective neutral carriers in cesium ion selective electrodes. Two plasticizers (NPOE and NPBnE) were studied. The new 14-crown-formazan 4a containing the 4-pyridyl N-oxide at the formazyl carbon exhibited the highest selectivity in cesium ion selective electrodes, especially towards the two low selectivity monovalent ions K(+) and NH4(+). Also, membranes containing the plasticizer NPBnE showed better cesium selectivity relative to most ions than those containing NPOE. Membranes containing 4a and variable compositions of plasticizers, potassium tetrakis-(p-chlorophenyl)borate (KTpClPB), and trioctylphosphine oxide (TOPO) were studied in order to prepare an electrode with the optimum cesium selectivity. The highest selectivity for cesium was achieved with the two electrodes designated d and e with membranes containing the ionophore 4a, NPBnE and KTpClPB with and without TOPO. Selectivities are reported relative to sodium, potassium, barium, calcium, ammonium, lithium, cobalt, and magnesium.

New 2-pyrazolines of anticipated molluscicidal activity.

A facile one-pot synthesis of 1-substituted carbamoyl or thiocarbamoyl-2-pyrazolines 6 is described. Also, the synthesis as well as the molluscicidal activity of 1,3,5-triaryl- (2), 1-acetyl-3,5-diaryl- (4) 2-pyrazolines are outlined.

Synthesis and biological activity of some new pyrimidine and thienopyrimidine derivatives.

The readily available 4-mercapto-6-methyl-2-phenyl-5-acetylpyrimidine (1) was alkylated with a variety of activated halomethylene compounds to give the corresponding thieno [2,3-d] pyrimidine derivatives 3a-h via the intermediate alkylmercaptopyrimidine derivatives 2b-h. The biological activity of the new compounds was screened against several strains of bacteria.