Postsynthetic Modification of Zeolite Internal Surface for Sustainable Capture of Volatile Organic Compounds under Humid Conditions.

Although low-cost, high-surface-area crystalline aluminosilicate zeolites have been recognized as promising adsorbents for the capture of volatile organic compounds (VOCs), their hydrophilic nature leads to a significant loss of performance owing to the ubiquitous presence of water vapor in the VOC stream. Herein, the aluminosilicate zeolites (i.e., mordenite and nanocrystalline ß) are functionalized via a solvothermal post-treatment with methyl iodide as the grafting agent. The methyl groups are primarily attached to the zeolite internal surface via covalent bonding between internal bridging O and -CH3, as evidenced by multiple analysis data. The static isotherms and diffusional studies clearly reveal a remarkable decrease in both the rate of water adsorption and the water affinity due to the attachment of methyl groups to the micropore walls, thus enhancing the water tolerance compared to that of pristine zeolites. In addition, CH3I-functionalized zeolites are investigated as adsorbents for the removal of benzene under dry and humid conditions, and their performance is compared to that of CH3Si(-OCH3)3-functionalized zeolites, wherein the methyl groups have been grafted onto the external surface. The results demonstrate that, although the benzene adsorption capacity under dry conditions is decreased upon internal surface functionalization, the loss of VOC adsorption capacity in the presence of H2O vapor is effectively prevented. By contrast, external surface functionalization is ineffective for preventing the negative effects of moisture upon the benzene adsorption capacity. As a result, CH3I-functionalized zeolites exhibit superior dynamic adsorption performance for benzene at 318 K under humid conditions (relative humidity: 80%), with a saturated adsorption capacity of 64.9 mg g-1. This work provides an easy strategy for tailoring the adsorption properties of aluminosilicate zeolites for adsorption/separation and other advanced applications.

Post-Synthesis Functionalization Enables Fine-Tuning the Molecular-Sieving Properties of Zeolites for Light Olefin/Paraffin Separations.

Zeolite molecular sieves are widely used in gas separation and shape-selective catalysis, but these applications often require discriminating differences as little as 0.1 Å. Molecular sieving with such size selectivity demands zeolites with highly tunable pore diameters and adsorption properties, which are technically challenging to prepare. Nevertheless, it is shown that a wide range of organic functional groups can be covalently functionalized onto the interior pore walls of the zeolites, MOR, LTL, FAU, and MFI, to systematically "tune" their effective pore diameters with respect to the size of organic groups. For organic functionalization, small and aggressive organic electrophiles are used (e.g., organo-halide and -diazonium) as grafting agents, which are accessible to the intracrystalline void space, forming a C-Ozeolite bond in a reaction with a bridging oxygen as proved by multiple analysis data. It is demonstrated that the post-functionalization can be used to tailor the molecular sieving action of a parent zeolite to give size-selective adsorbents for light olefin/paraffin separations. 4-Methoxybenzene-functionalized MOR separates ethylene from ethane with an ideal-adsorbed-solution-theory selectivity of ≈5873, whereas toluene-grafted MOR completely separates propylene/propane mixtures. Therefore, tailoring the molecular-sieving properties of zeolites by organic functionalization broadens their applications to challenging separations.

Dynamic adsorption/desorption of p-xylene on nanomorphic MFI zeolites: Effect of zeolite crystal thickness and mesopore architecture.

Zeolites have attracted great interest as an adsorbent for the removal of volatile organic compounds. However, they suffer from low adsorption capacities due to severe diffusion limitations. Here, the effects of zeolite thickness and mesopore architecture on dynamic adsorption of p-xylene have been examined with a number of MFI-type zeolites with different crystal thicknesses and mesopore openings (i.e. open mesopore, constricted mesopore), which were prepared via hydrothermal synthesis with various organic structure-directing agents and post-synthetic desilication. The results showed that the breakthrough time of MFI zeolite could be improved by more than 2.3 times by reducing the crystal thickness of zeolite to a single-unit-cell dimension (∼2 nm). The time improvement can be attributed to the short diffusion path length that results in easy access of p-xylene to intracrystalline micropores and a large external crystal surface area. In the case of mesopore openings, the presence of constricted mesopores caused the mass transfer of p-xylene into zeolite adsorbents to slow down while open mesopores did not. Furthermore, mesopore opening is an important factor for the desorption behavior of p-xylene. Adsorbed p-xylene by mesoporous zeolites could be desorbed at lower temperatures only when facile diffusion to the exterior through mesoporous channels was possible.

Risk diagnosis based on diameter of abdominal aortic aneurysm.

An abdominal aortic aneurysm doesn't result in specific symptoms, and so providing a successful diagnosis can be challenging. Patients may require surgery for successful treatment, with the risk of aortic rupture being dependent on diameter. In this study, a CT screen of a patient with an aneurysm of the abdominal aorta was processed. In order to provide a more accurate and comfortable diagnosis, and to more easily determine the diameter of the abdominal aortic aneurysm, the Sobel and Top-hat methods were employed. Using a filtered screen overlap for the CT scan, the aortic diameter of a patient could be compared with the diameter of a healthy individual, thus allowing an immediate and accurate comparison. It was found that with a diameter of more than 40 mm the risk of rupture is higher.

Phase II trial of combination chemotherapy with gemcitabine, 5-fluorouracil and cisplatin for advanced cancers of the bile duct, gallbladder, and ampulla of Vater.

AIMS AND BACKGROUND: For advanced cancers of the bile duct, gallbladder and ampulla of Vater, there are only a few treatment options. We explored the efficacy of the combination of gemcitabine, 5-fluorouracil and cisplatin for advanced biliary cancers. METHODS: From September 2003 to April 2010, 28 patients with recurrent or metastatic biliary tract cancer were enrolled. A treatment regimen consisting of gemcitabine (800 mg/m² at a fixed dose rate on days 1 and 8), 5-fluorouracil (1 g/m²/day continuous infusion for 4 days) and cisplatin (60 mg/m² on day 2) was repeated every 3 weeks. RESULTS: One (3.6%) patient showed complete response, 8 (28.6%) partial response, 14 (50%) stable disease and 5 (17.9%) disease progression. Overall, the objective response rate was 32.1% (95% CI, 17.9-50.6%) and the disease control rate was 82.1% (95% CI, 64.4-92.1%). Median progression-free survival and overall survival were 7.6 months (95% CI, 5.5-9.7) and 11.2 months (95% CI, 6.8-15.5), respectively. G3/4 neutropenia was observed in 44 (24.3%) of 181 cycles and G3/4 thrombocytopenia in 48 (26.5%) of 181 cycles. There was no treatment-related mortality. CONCLUSIONS: The combined regimen of gemcitabine, 5-fluorouracil and cisplatin has comparable activity for patients with advanced cancer of the bile duct, gallbladder and ampulla of Vater. Toxicity was tolerable but substantial.

Enantioselective carbonyl reduction of eperisone in human liver microsomes.

Eperisone, 4-ethyl-2-methyl-3-piperidinopropiophenone, is a centrally acting muscle relaxant widely used to relieve muscle stiffness and back pain. In this study, enantioselectivity for carbonyl reduction of eperisone was investigated in human liver microsomes, and the enzymes involved in the carbonyl reduction were characterised. Carbonyl reduction of eperisone predominantly occurred in microsomal fractions and 11ß-hydroxysteroid dehydrogenase type 1(11ß-HSD 1) played a major role in this reaction as judged by selective inhibition of the activity by BVT-14225 and KR-66344. The kinetic study with (+)-S- and (-)-R-eperisone showed that the formation of the carbonyl reduced metabolite (M5) from the (-)-R-isomer was more efficient than that from the (-)-S-isomer. As eperisone is a racemic compound with one chiral centre, the carbonyl reduced metabolite of eperisone (M5) may have four possible diastereoisomeric structures. Chiral separation of incubation mixtures of racemic eperisone with human liver microsome revealed that (1S, 2S)-M5 and (1R, 2R)-M5 were generated specifically from (+)-S- and (-)-R-eperisone, respectively. Selective formation of anti-diastereomers was further confirmed by incubation of individual enantiomer with microsomes. Carbonyl reduction of eperisone by microsomal 11ß-HSD 1 may significantly contribute to the metabolic disposition of eperisone in human and (-)-R-isomer is preferentially reduced by this enzyme.

Development and Application of Sexual Rights Awareness Scale for Female Adults.

PURPOSE: This study aimed to develop a sexual rights awareness scale for female adults and to further examine the differences after educational sessions for sexual rights awareness with female adults. METHODS: Convenient sampling was employed to recruit 152 participants. A self administered questionnaire was developed to explore adult females' understanding of sexual rights awareness. In the next phase, education was provided over 3 consecutive sessions to 28 female university students. Factor analysis and Cronbach's alpha were performed in order to test validity and reliability of the educational sessions. The Wilcoxon rank test was used to identify the differences between pretesting of sexual rights awareness knowledge and post testing after educational sessions was provided. RESULTS: After conducting factor analysis, 5 factors explained 63.3% of the total variance, namely: I) sexuality education, II) prejudice & biasaberration, III) sexual satisfaction, IV) safe & equal sexuality, and V) sexual autonomy. A Cronbach's alpha of 17 items was 0.80. After the education sessions, there was a significant increase in sexual rights awareness. CONCLUSION: The Sexual rights awareness questionnaire is acceptable as a tool for measuring the level of education in studies. Future research should aim at conducting comparison studies of sexual rights awareness between sexes and cultural differences with larger populations which will further help to develop and to strengthen the rigor with in methodologies.

Use of headspace mulberry paper bag micro solid phase extraction for characterization of volatile aromas of essential oils from Bulgarian rose and Provence lavender.

In this study, a new sampling method called headspace mulberry paper bag micro solid phase extraction (HS-MPB-mu-SPE) combined to gas chromatography-mass spectrometry has been applied for the analysis of volatile aromas of liquid essential oils from Bulgarian rose and Provence lavender. The technique uses an adsorbent (Tenax TA) contained in a mulberry paper bag, minimal amount of organic solvent. Linearities for the six-points calibration curves were excellent. LOD values were in the rage from 0.38 ng mL(-1) to 0.77 ng mL(-1). Overall, precision and recovery were generally good. Phenethyl alcohol and citronellol were the main components in the essential oil from Bulgarian rose. Linalyl acetate and linalool were the most abundant components in the essential oils from true lavender or lavandin. Additionally, the relative extraction efficiencies of proposed method have been compared with HS-SPME. The overall extraction efficiency was evaluated by the relative concentration factors (CF) of the several characteristic components. CF values by HS-MPB-mu-SPE were lower than those by headspace solid phase microextraction (HS-SPME). The HS-MPB-mu-SPE method is very simple to use, inexpensive, rapid, requires small sample amounts and solvent consumption. In addition, this method allowed combining of extraction, enrichment, and clean-up in a single step. HS-MPB-mu-SPE and GC/MS is a promising technique for the characterization of volatile aroma compounds from liquid essential oils.

Pharmacokinetics and tissue distribution of a novel PDE5 inhibitor, SK-3530, in rats.

AIM: To investigate the pharmacokinetic profile and tissue distribution of a novel phosphodiesterase type 5 inhibitor, 5-ethyl-2-{5-[4-(2-hydroxy-ethyl)-piperazine-1-sulfonyl]-2-propoxy-phenyl}-7-propyl-3,5-dihydro-pyrrolo(3,2-d)pyrimidin-4-one (SK-3530), in rats after administration of the (14)C-labeled compound. METHODS: The pharmacokinetic parameters of SK-3530 were measured based on the total radioactivity and parent SK-3530 concentration in rat plasma after intravenous and oral administration. The tissue distribution of total radioactivity after a single oral administration of [(14)C]SK-3530 at a dose of 40 mg/kg was assayed. The plasma protein binding rates of SK-3530 were assessed by in vitro and ex vivo assay. RESULTS: The total radioactivity profiles showed linear pharmacokinetics. The maximum plasma concentration and area under the curve of the parent SK3530 were 10%-20% compared to those of the total radioactivity. After the oral administration of [14C]SK-3530, the radioactivity was widely distributed in all tissues, and the tissue/plasma ratio of the radioactivity 1 h after administration was calculated as 0.5-2.6 with the exception of excretory organs. A relatively high penetration was shown in the adrenal glands, liver, and lung. In vitro and ex vivo plasma protein binding assay by ultrafiltration showed a considerably high binding rate of more than 97%. CONCLUSION: SK-3530 was relatively well absorbed in the gastrointestinal tract and showed linear pharmacokinetics over the investigated dose range. SK-3530 had low oral bioavailability due to a high, first-pass metabolism.

Intake of dietary soy isoflavones in relation to perimenstrual symptoms of Korean women living in the USA.

This study was conducted to identify the potential relationship between the dietary intake level of soy isoflavones and perimenstrual symptomatology. The research design was a cross-sectional study. The sample was made up of 84 Korean women living in the USA, aged 28-40 years. The Moos Menstrual Distress Questionnaire (MDQ) and the Food Frequency Questionnaire were used as measurement tools. The soy isoflavone intake was significantly correlated with MDQ scores in the menstrual phase. In conclusion, the beneficial effect of dietary soy isoflavones on certain menstrual symptoms was established, suggesting that soy isoflavones could be one of the dietary factors related to the complexity of premenstrual syndrome (PMS). The positive effect of soy isoflavones on PMS warrants further study.

The metabolism and excretion of 2-methylaminoethoxycarbonyl-4,4'-dimethoxy-5,6,5',6'-dimethylenedioxybiphenyl-2'-carboxylic acid (DDB-S) in rats and human.

The metabolism and excretion of 2-methylaminoethoxycarbonyl-4,4'-dimethoxy-5,6,5',6'-dimethylenedioxybiphenyl-2'-carboxylic acid (DDB-S) were investigated in both rats and humans using liquid chromatography/electrospray ion trap mass spectrometry (LC/ESI-MS/MS). In rats, DDB-S was rapidly eliminated from the body after a single 50 mg/kg intravenous injection, with urine being a major excretion route. DDB-S was metabolically stable; approximately 96% of the administered dose was recovered in the form of the parent compound. Nevertheless, 12 metabolites were detected in the urine and feces collected from DDB-S-treated rats. The structural characterizations of the metabolites were elucidated from the MS(n) spectral analysis. Because DDB-S has a pseudo-symmetrical methylenedioxy biphenyl structure, regioselective deuterium-substituted DDB-S (d(5)-DDB-S) was used to assign the metabolic modification. The major metabolic pathways of DDB-S were identified as demethylenation of the methylenedioxy moiety, O-demethylation of the methoxy moiety and glucuronidation. In addition, N-demethylation of the methylaminoethyl group was also detected as a minor reaction.

Headspace solid-phase microextraction for characterization of fragrances of lemon verbena (Aloysia triphylla) by gas chromatography-mass spectrometry.

Natural fragrances from lemon verbena (Aloysia triphylla) were studied by headspace solid phase microextraction (HS-SPME) techniques followed by gas chromatography-mass spectrometry (GC-MS), with six different fibre coatings being tested to evaluate the extraction efficiencies of several selected compounds. A total of 14 compounds were identified in the fragrances of lemon verbena. Geranial and neral were detected as major components and alpha-pinene, beta-pinene, beta-caryophyllene, and curcumene as minor components. Enantiomeric analysis of chiral compounds from lemon verbena was carried out on a chiral column. alpha-Pinene, limonene, and camphor in the fragrances emitted from lemon verbena were found in the (+), (-), and (-) forms, respectively.

Comparative study of extraction techniques for determination of garlic flavor components by gas chromatography-mass spectrometry.

Several sampling techniques based on steam distillation (SD), simultaneous distillation and solvent extraction (SDE), solid-phase trapping solvent extraction (SPTE), and headspace solid-phase microextraction (HS-SPME) have been compared for the determination of Korean garlic flavor components by gas chromatography-mass spectrometry (GC-MS). Diallyl disulfide (57.88%), allyl sulfide (23.59%), and diallyl trisulfide (11.40%) were found to be the predominant flavor components of garlic samples extracted by SDE whereas these components were at levels of 89.77%, 2.43%, and 3.89% when the same sample was extracted by SD, 97.77%, 0.17%, and 0.10% by SPTE, and 97.85%, 0.01%, and 0.01% by HS-SPME using the 50/30-microm divinyl benzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber. Thermal degradation of components such as allyl methyl sulfide, dimethyl disulfide, and thiirane were observed for SDE and SD but not for SPTE or HS-SPME. HS-SPME had several advantages compared with SD, SDE, and SPTE-rapid solvent-free extraction, no apparent thermal degradation, less laborious manipulation, and less sample requirement. Five different fiber coatings were evaluated to select a suitable fiber for HS-SPME of garlic flavor components. DVB/CAR/PDMS was most efficient among the five types of fiber investigated.

Comparison of different extraction methods for the analysis of fragrances from Lavandula species by gas chromatography-mass spectrometry.

Various sampling techniques including solid-phase trapping solvent extraction (SPTE), headspace solid-phase microextraction (HS-SPME), reduced pressure steam distillation (RPSD) and simultaneous steam distillation-solvent extraction (SDE) were compared for the gas chromatography-mass spectrometry of the fragrances from the Lavandula species. Linalyl acetate (35.44%) and linalool (18.70%) were predominant components of Hidcote lavender samples obtained by SPTE whereas those levels were 2.63-4.04 and 36.80-43.47% in the same samples by RPSD and SDE, respectively. The partition coefficients between the headspace gaseous phase and HS-SPME fiber, and the relative concentration factors of the four characteristic components of the lavender were measured for relative evaluation of the fiber efficiency. Five different coatings were evaluated and 100-microm poly(dimethylsiloxane) was the most efficient for the successful extraction of lavender fragrances. A total of 43 compounds were identified by SPTE and gas chromatography-mass spectrometry from four Lavandula species. Lavandula angustifolia Hidcote species, which contains a higher level of linalyl acetate and linalool but little camphor, was evaluated as the highest quality among the four different Lavandula species.