Fourth Fraction Research Articles

PENINGKATAN KADAR PATCHOULI ALCOHOL PADA MINYAK NILAM (Pogostemon cablin Benth) DENGAN METODE DISTILASI FRAKSINASI VAKUM

The quality of nilam (Pogostemon cablin Benth) oil depend on it patchouli alcohol value. At there time nilam farmers just has produced nilam oil with patchouli alcohol value about 26–28 percent. To increase this value, fractional vacuum distillation had been done in this study. Nilam oil has been isolated from drying leaf of nilam plant. Patchouli alcohol in this oil was analyzed by gas chromatography, next the oil was distillated by fractional vacuum and the patchouli alcohol was determined from each fraction. This study showed that fractional vacuum distillation of nilam oil gives a higher patchouli alcohol value. The increasing was 23.3387 percent; from 35.022 percent at nilam oil before fractination vacuum distillation to 58.3515 percent at the third fraction from fractional vacuum distillation. In fact, the fourth fraction had the highest patchouli alcohol, but it had dark colour so isn’t fill the standard quality.

Hemolytic Uremic Syndrome

Hemolytic uremic syndrome (HUS) is a thrombotic microangiopathy defined by thrombocytopenia, nonimmune microangiopathic hemolytic anemia, and acute renal failure. The most frequent form is associated with infections by Shiga-like toxin-producing bacteria (STEC-HUS). Rarer cases are triggered by neuraminidase-producing Streptococcus pneumoniae (pneumococcal-HUS). The designation of aHUS is used to refer to those cases in which an infection by Shiga-like toxin-producing bacteria or S. pneumoniae can be excluded. Studies performed in the last two decades have documented that hyperactivation of the complement system is the pathogenetic effector mechanism leading to the endothelial damage and the microvascular thrombosis in aHUS. Recent data suggested the involvement of the complement system in the pathogenesis of STEC-HUS and pneumococcal-HUS as well. Clinical signs and symptoms may overlap among the different forms of HUS; however, pneumococcal-HUS and aHUS have a worse prognosis compared with STEC-HUS. Early diagnosis and identification of underlying pathogenetic mechanism allows instating specific support measures and therapies. In clinical trials in patients with aHUS, complement inhibition by eculizumab administration leads to a rapid and sustained normalization of hematological parameters with improvement in long-term renal function. This review summarizes current concepts about the epidemiological findings, the pathological and clinical aspects of STEC-HUS, pneumococcal-HUS, and aHUS, and their diagnosis and management.

Development of a procedure for the sequential extraction of substances binding trace elements in plant biomass

This work investigates how the amounts of some important substances in a plant, and their behaviour inside the plant, depend on the levels of stress placed on the plant. To this end, model plant spinach (Spinacia oleracea L.) was cultivated on soil treated with sewage sludge. The sewage sludge contained various trace elements (As, Cd, Cu, Zn), and the uptake of these trace elements placed the plant under stress. Following this, a sequential extraction procedure was employed to determine the levels and distributions of trace elements within the most important groups of compounds present in the spinach plants. Since the usual five-step sequential extraction procedure provides only general information on the distributions of elements within individual groups of organic compounds, due to the wide range of organic compounds within the individual fractions, this scheme was extended and improved through the addition of two solvent extraction steps-a butanol step (between the ethyl acetate and methanol solvent steps) and an H(2)O step (after the methanol+H(2)O solvent step). The distributions and levels of the trace elements within the main groups of compounds in spinach biomass was investigated using this new seven step sequential extraction (water free solvents: petroleum ether (A) --> ethyl acetate (B) --> butanol (C) --> methanol (D) --> water solvents: methanol+H(2)O (1+1; v/v) (E) --> H(2)O (F) --> methanol+H(2)O+HCl (49.3+49.3+1.4; v/v/v) (G)). The isolated fractions were characterized using IR spectroscopy and the trace element contents were determined in the individual fractions. Lipophilic compounds with low contents of Cd, Cu and Zn were separated in the first two fractions (A, B). Compounds with higher As contents (11.5-12.8% of total content) were also extracted in the second fraction, B. These two fractions formed the smallest portion of the isolated fractions. Low molecular compounds from secondary metabolism and polar lipids were separated in the third (C) and fourth (D) fractions, and high molecular compounds (mainly polypeptides and proteins) separated in the fifth and sixth fractions (E, F). The addition of the H(2)O solvent step was particularly useful for separating compounds that have a significant impact on trace element bounds. The methanol fraction was dominant for all treatments, and a significant decrease in the spinach biomass separated in this fraction was observed when the soil was treated with sewage sludge. Most of the As (35.5-38.8% of total content), Cu (45.0-51.6%) and Zn (39.8-47.2%) was also determined in this fraction. The G fraction (obtained after acid hydrolysis) contained polar compounds. Most of the Cd was also found in this fraction, as was a significant amount of Zn. Non-extractable residues formed the last fraction (polysaccharides, proteins).

Quick sequential procedure for speciation analysis of heavy metals in soils by supersonic extraction

In order to improve the extraction efficiency and reduce the operation time, supersonic energy by means of supersonic bath was used to the modified Tessier sequential extraction for speciation analysis of heavy metals in soils. Extractable contents of Cu, Fe, Mn, Ni, Pb and Zn were measured by flame atomic absorption spectroscopy. The merit of the supersonic extraction (SE) applied to the modified Tessier, method is not only that the operation time for the first 4 fractions was reduced from ca 18 h to 8 h, comparing with conventional extraction (CE), but also the extraction efficiency was higher. There were no significant differences between the data obtained by the proposed method using supersonic extraction and the reference values of the standard reference materials of EES-2 and EES-3. The results for both of SE and CE in the soil samples were consistent. The extractable Cu, Ni and Zn in the sample No. 1 were mainly associated with the third fraction (Fe-Mn oxides fraction), and fourth fraction (organic matter fraction) in the sample No. 2. The extractable Fe and Mn were all mainly associated with the third fraction, and Pb the fourth fraction in both of the samples. The effects of varying concentrations of hydroxylamine hydrochloride on the extraction of metals were also studied.

Apical Sorting of Adamts13 in Madin-Darby Canine Kidney (MDCK) Cells Requires Cub Domains Via Its Interaction with Detergent-Insoluble Glycosphingolipid- and Cholesterol-Enriched Rafts.

ADAMTS13, a member of a disintegrin and metalloprotease with thrombospondin type 1 repeats family, is mainly synthesized in the liver and secreted into the blood stream. It limits platelet aggregation in small arteries by cleaving the Tyr1605-Met1606 bond of von Willebrand factor (VWF). ADAMTS13 consists of a propeptide, a metalloprotease domain and a disintegrin domain, first thrombospondin type 1 repeat (TSP1), followed by a Cys-rich domain and a spacer domain. The carboxyl terminus of ADAMTS13 contains seven more TSP1 repeats and two CUB domains. The distal carboxyl terminal TSP1 repeats and CUB domains of ADAMTS13 appeared not to be essential for cleavage of VWF, but they might be important for ADAMTS13 biosynthesis and intracellular sorting. In this study, we determined: 1) the polarity of ADAMTS13 secretion in MDCK cells; 2) the signals that direct polarized sorting of ADAMTS13; 3) the platform by which ADAMTS13 is sorted. MDCK II cells were stably transfected with plasmids encoding a full-length ADAMTS13 and a series of carboxyl termini-deleted ADAMTS13 variants. The polarity of full-length ADAMTS13 and its variants was determined in a Transwell™ filter system by Western blotting with anti-V5 and by proteolytic activity toward VWF in the conditioned medium. We showed that full-length ADAMTS13 was predominantly sorted apically, with an approximately 75% of protein and 85% of proteolytic activity of ADAMTS13 detected in the apical domain of MDCK cells. An ADAMTS13 variant (del1) lacking two CUB domains was randomly sorted into both apical and basolateral domains of MDCK cells, with an approximately 52% of protein and 49% of proteolytic activity detected apically. The ADAMTS13 variant (del2) deleted after the spacer domain was also randomly secreted, but the ADAMTS13 variant (del3) deleted after the Cys-rich domain was sorted apically, with an approximately 92% of protein detected in the apical domain of MDCK cells. These data suggested the presence of an apical sorting signal in the CUB domains and Cys-rich domain, and an inhibitory sorting signal in the spacer domain and/or in the TSP1 2~8 repeats. Moreover, the ADAMTS13 variant (del4) deleted after the first TSP1 was predominantly sorted into the basolateral domain of MDCK cells, with an approximately 30% of protein detected apically, suggesting the presence of basolateral signal in the first TSP1 repeat. The ADAMTS13 variants deleted after the disintegrin domain (del5) and the metalloprotease domain (del6) were sorted apically again. These data suggested the presence of multiple sorting signals in ADAMTS13 protein. The polarity of ADAMTS13 sorting may depend on the overall strength of apical, basolateral and inhibitory signals in the protein. By Triton-X 100 solubility at 4 °C and sucrose gradient analyses, we showed that full-length ADAMTS13 protein was detected in top third and fourth fraction of the gradient where a plasma membrane protein, caveolin-1 was located, suggesting that full-length ADAMTS13 was incorporated into the detergent-insoluble glycosphingolipid and cholesterol-enriched microdomains, i.e lipid rafts in the biosynthetic and trafficking pathway. Deletion of two CUB domains abolished ADAMTS13 association with lipid rafts and randomized its sorting. Therefore, we conclude that apical sorting of ADAMTS13 in MDCK cells may be mediated by lipid rafts, and that the CUB domains of ADAMTS13 are required for raft association and apical sorting of ADAMTS13.

Identification of organic compounds in atmospheric aerosol particles by on-line supercritical fluid extraction–liquid chromatography–gas chromatography–mass spectrometry

Atmospheric particles were collected with a high-volume sampling system at an urban site in Helsinki (Finland). The samples were analysed by on-line coupled supercritical fluid extraction–liquid chromatography–gas chromatography–mass spectrometry (SFE–LC–GC–MS). The aerosol sample was first extracted by SFE. The extract was then transferred to a liquid chromatograph where it was fractionated into four fractions according to polarity. Each fraction from the liquid chromatograph was transferred to a gas chromatograph by large-volume injection, where final separation was carried out. The first LC fraction (280 μl) contained nonpolar compounds, such as n-alkanes, hopanes and steranes. The second fraction (840 μl) included polycyclic aromatic hydrocarbons (PAHs) and alkyl-PAHs, while the third and fourth fractions (840 μl each) contained more polar compounds, such as n-alkan-2-ones, n-alkanals, oxy-PAHs and quinones.

03/02012 Photo-oxidation products of petroleum hydrocarbons in the Eastern Red Sea coastal waters: Al-Lihaibi, S. S. Environment International, 2003, 28, (7), 573–579

The level of dissolved oil residues as well as the oxygenated petroleum hydrocarbons in the seawater of the affected area of Jeddah coast, Red Sea was estimated. The dissolved/dispersed petroleum hydrocarbons concentration was found minimal. The minimum level may be attributed to the action of the weathering processes. Selected samples of the dichIoromethane extracts of seawater were fractionated, using silica gel columns, into four fractions eluted with solvents of increasing polarity. The fluorescence intensity of these fractions was measured at three different pairs of excitation and emission wavelengths using ultraviolet fluore;;cence spectrofluorophotomelly (UVF). The total fluorescence intensity of the fractions at 280 run excitation, 327 run emission wavelengths and 310 om excitation, 360 nm emission wavelengths exceeds the fluorescence intensity of the whole extract by more than two orders of magnitude. The estimation of higher molecular mass oxygenated compounds in the fourth fractions, read at 380 run excitation, 430 run emission wavelengths. indicates rather Iow concentrations of < I ).!g 1- I hydroxypyrene equivalents. However, the polar fractions (eluted with acetone) account for more than 25% of the total fluorescence intensity of all fractions combined at eacb pair of wavelengths. The characterization of the products causing the fluorescence particularly the high molecular mass compounds still presents difficulties. Preliminary GCIMS results revealed some evidence for petroleum hydrocarbon oxidation products. Alkyl isobenzofumnones bave been found in some seawater extracts. This is an ongoing project to characterize and identifY additional compounds from these extracts.

Determination of biogenic organic compounds in airborne particles by solvent extraction, derivatisation and mass spectrometric detection

Atmospheric oxidation of biogenic hydrocarbons such as monoterpenes is believed to be a globally significant source of aerosols. Secondary and primary biogenic hydrocarbons were determined in airborne particles. The particles were collected on quartz fibre filters in summer 2001 in a Norway spruce forest (Fichtelgebirge, Germany) at two different heights. The filters were Soxhlet extracted, the extract was concentrated and separated into five fractions with different polarity after flash chromatography and then measured with GC-MS. The first, second and third fractions were measured without derivatisation, the fourth fraction was silylated with BSTFA and the fifth fraction was methylated with BF3-Methanol. Many single compounds were detected and the highest concentrations were found for the polar components, especially for the dicarboxylic acids. Further quantified compounds include alkanes, ketones, aldehydes and carboxylic acids. Of special interest were the terpene oxidation products as pinonaldehyde, norpinic acid, pinic acid and pinonic acid. Typical concentrations of single compounds were in the sub ng m−3 range. Concentrations of terpene oxidation products are low in comparison to the terpene concentrations. More primary than secondary biogenic organic compounds were identified.

Photo-oxidation products of petroleum hydrocarbons in the Eastern Red Sea coastal waters

The level of dissolved oil residues as well as the oxygenated petroleum hydrocarbons in the seawater of the affected area of Jeddah coast, Red Sea was estimated. The dissolved/dispersed petroleum hydrocarbons concentration was found minimal. The minimum level may be attributed to the action of the weathering processes. Selected samples of the dichloromethane extracts of seawater were fractionated, using silica gel columns, into four fractions eluted with solvents of increasing polarity. The fluorescence intensity of these fractions was measured at three different pairs of excitation and emission wavelengths using ultraviolet fluorescence spectrofluorophotometry (UVF). The total fluorescence intensity of the fractions at 280 nm excitation, 327 nm emission wavelengths and 310 nm excitation, 360 nm emission wavelengths exceeds the fluorescence intensity of the whole extract by more than two orders of magnitude. The estimation of higher molecular mass oxygenated compounds in the fourth fractions, read at 380 nm excitation, 430 nm emission wavelengths, indicates rather low concentrations of <1 μg l −1 hydroxypyrene equivalents. However, the polar fractions (eluted with acetone) account for more than 25% of the total fluorescence intensity of all fractions combined at each pair of wavelengths. The characterization of the products causing the fluorescence particularly the high molecular mass compounds still presents difficulties. Preliminary GC/MS results revealed some evidence for petroleum hydrocarbon oxidation products. Alkyl isobenzofuranones have been found in some seawater extracts. This is an ongoing project to characterize and identify additional compounds from these extracts.

Heavy Metal Fractionation in Sediments from the Tinto River (Spain)

Seventeen sediment samples from the Tinto and its main tributaries were analyzed for this study. For each of these samples, the association of metals (Cu, Zn, Cd, Pb, Fe, Ni, Cr and Co) was determined in four fractions: acid soluble, reducible, oxidizable and residual. The total metal content was also determined. Results showed high mean concentrations of Fe (109,000 mg/kg), Pb (2330 mg/kg), Zn (901 mg/kg), Cu (805 mg/kg), and Cd (2.7 mg/kg) in the sediments studied. However, the mean values found for Co (21 mg/kg), Cr (56 mg/kg) and Ni (17 mg/kg) are comparable to those in unpolluted areas. Heavy metal fractionation of the Tinto River sediments showed that the metals with the greatest mobility (i.e., metals that could pass easily into the water under changing environmental conditions) are Cd and Zn. These are the metals that showed the highest percentages in the first two fractions (the most labile) and the lowest percentages in the residual fraction. However, the percentage of metal present in the fourth fraction (residual) was high for Cr (78%), Ni (71%), and Co (66%), which implies that these metals are strongly linked to the sediments.

Detection of alkanes and alkenes for identifying irradiated cereals

AbstractAlkanes and alkenes can be produced from lipids in maize, brown rice, and wheat by irradiation. The purpose of this study was to determine whether the detection pattern of the hydrocarbons can be used for identifying postirradiation of cereals. Maize, brown rice, and wheat were irradiated at 0.5, 1, and 3 kGy. Oils were extracted from the samples using hexane and anhydrous Na2SO4. Hydrocarbon‐containing fractions, isolated using Florisil column chromatography, were analyzed using gas chromatography (GC). The first six Florisil column chromatography fractions of 10 mL each were collected. Prominent radiation‐induced alkenes 17∶1, 16∶2, 17∶2, and 16∶3 appeared mainly in the third, fourth, and fifth fractions. Those three fractions were combined and evaporated to a total volume of 4 mL for GC analyses. Alkenes 17∶1, 16∶2, 17∶2, and 16∶3 were detected in all irradiated samples but not in the non‐irradiated ones. The levels of the hydrocarbons changed little by roasting the nonirradiated and irradiated cereals.

Photoinductive properties of soil humic acids and their fractions obtained by tandem size exclusion chromatography–polyacrylamide gel electrophoresis

Humic acids (HAs) from three soils of different origin (Chernozem, Ferralsol and Ranker) have been fractionated by coupling size exclusion chromatography (SEC) and polyacrylamide gel electrophoresis (PAGE) on three fractions (fractions A, B, C + D) with different molecular sizes (MSs) and exactly defined electrophoretic mobility (EM). Fractions identically marked had similar EM and MS, independently of HA sources. The photoinductive properties of the whole HAs and their fractions were compared by studying the photoinduced transformation of fenuron at 365 nm. High MS fractions A and B appeared to exhibit poor photoinductive activities compared to the whole HAs, whereas low MS fraction C + D in Chernozem and Ranker were more efficient than the whole HAs. A fourth intermediary fraction containing a mixture of fractions B and C + D with small amount of D was shown to photoinduce poorly the transformation of fenuron. It was therefore concluded that the molecules capable of photoinducing the transformation of fenuron were mainly contained in fraction D. Fluorescence properties of Chernozem HA and its fractions have been tested. Fraction C + D exhibited a very similar fluorescence emission spectrum in comparison with the whole HA and in contrast, the fractions A and B emitted very weakly.

Use of microwave single extractions for metal fractionation in sewage sludge samples

In the present study the original Tessier sequential extraction method has been applied for metal fractionation in sewage sludge samples collected from an urban wastewater treatment plant and from one domestic olive oil factory. The results obtained by this conventional method were compared with those estimated from direct microwave single extractions, in order to reduce the conventional treatment time and simplify the experimental task. Microwave extraction conditions (heating time and power) were specifically optimised for Cu, Cr, Ni, Pb and Zn with the aim of obtaining similar results to that of the original Tessier method. Extractable metal contents obtained by both compared methodologies were measured by flame atomic absorption spectrometry (FAAS). In the three first fractions of the Tessier method, the analytical results were similar to those obtained from microwave single extractions for most of the elements in the two samples studied. In contrast, the fourth fraction could not be directly extracted using the microwave procedure and must be leached from the solid residue of the reducible fraction, using a two-step procedure. The overall extraction efficiency obtained by both single and sequential microwave extractions were similar for all metals (recoveries between 93.9 and 102.3%), except for Cu in the two samples studied and for Cr in the olive oil sludge (OOS) (recoveries <32%). The precision of the proposed microwave single extraction method was <8.5% for all metals in the two samples.

Toxinological and immunological studies of capillary electrophoresis fractionated Chrysaora quinquecirrha (Desor) fishing tentacle and Chironex fleckeri Southcott nematocyst venoms

Repeated runs of capillary electrophoresis (CE) were used to study partially-purified jellyfish nematocyst venom protein in concentrations sufficient to perform toxinological assays. Nematocyst venoms from Chironex fleckeri ( Cf) and Chysaora quinquecirrha were processed. The CE eluate was divided into quadrants by scanning protein content. The fourth fraction of both jellyfish venoms, contained proteins with the smallest molecular weight components, which were responsible for the highest hemolysins and the humoral and cell-mediated immunological activity. Cytotoxic Cf lethal factor activity against human liver cells was widely dispersed throughout both venoms but more prominent in fraction 4. A V β receptor human T-cell repertoire was not species-specific for either crude or fractionated jellyfish nematocyst venom.

Cadmium reactivity in metal-contaminated soils using a coupled stable isotope dilution-sequential extraction procedure.

To better understand the intrinsic reactivity of Cd, four soils having diverse sources of Cd contamination (total Cd: 22-34 mg kg(-1)) were investigated using a stable isotope dilution-sequential extraction procedure (SID-SEP) during a 59-week incubation. Samples were spiked with carrier-free 111Cd and periodically extracted into five operationally defined fractions; the 111Cd:10Cd ratios were measured by inductively coupled plasma-mass spectrometry. The total labile pool of Cd (E value) was calculated as well as the labile Cd within each extracted fraction. Results for three of the soils (Cd sources: natural, sewage sludge, smelter emissions) were quite similar. The overall %E after 2-week equilibration was 35-49% of total soil Cd. Within fraction 2 (sorbed/carbonate), 70-75% of the Cd was isotopically labile, while within fraction 3 (oxidizable) only 35-41% of the Cd was labile within 2 weeks. The fourth (reducible) and fifth (residual) fractions were dominated by nonlabile Cd. Although all E values increased somewhat from 2 to 59 weeks, none of the extracted fractions reached isotopic equilibrium with the soluble/exchangeable Cd extracted during step 1. Because fractions 2 and 3 dominated the native Cd in all three soils, the total labile pool was contributed primarily (85-98%) by these two fractions. A fourth soil (mine spoil-contaminated) was demonstrably different: after 2 weeks, the overall %E was just 13 and, although 82% of the total Cd was present in the oxidizable fraction, just 2% of that was isotopically labile. The nonlability of Cd in this soil could be ascribed to the predominance of inorganic forms, most likely occluded Cd in sphalerite. No single Cd fraction from the SEP nor any combination of fractions showed a good correspondence with the size of the isotopically labile pool. Our results suggest that conventional SEPs may be of limited utility for predicting bioavailability, for example, during ecological risk assessment.

Partial lung shield for TBI

In this study, AP/PA setup was used with a 4 MV linear accelerator. The prescribed dose is 1000 cGy, with a dose per fraction of 200 cGy. One of the simplest lung dose determinations is the nomograph relating dose correction factor and patient thickness. To save time in taking port film in every treatment, lung block is used in alternating fashion: anterior blocks are used in the second and fourth fraction and posterior block is used in the third and fifth fraction. If we set the average correction factor for the lower density lung to 1.18, the six open fields will deliver an average of 708 cGy to the lung. To limit the lung dose to 10 Gy, each blocked field should deliver 73 cGy. Measurements showed that a thickness of slightly less than 1 cm of cerrobend provides approximately 65% transmission, which approximates the desired 73% broad beam transmission. The proper transmission of the partial lung shield is verified by measurements made for the patients with diodes placed at the entrance and the exit side of the lung. While we describe a particular setup, the procedure can be modified to accommodate different dose fraction. There are many ways to deliver the TBI dose, and the method of constructing the partial lung shield described here is one of the many methods that may be used to limit the dose to the lung.

An automated HPLC method for the fractionation of polychlorinated biphenyls, polychlorinated dibenzo‐p‐dioxins, and polychlorinated dibenzofurans in fish tissue on a porous graphitic carbon column

AbstractThe Ah (aryl‐hydrocarbon) hydroxylase‐receptor active polychlorinated biphenyls (PCBs), polychlorinated dibenzo‐p‐dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were fractionated by an automated high‐performance liquid chromatography (HPLC) system using the Hypercarb™ porous graphitic carbon (PGC) column. This commercially available column was used to fractionate the di‐, mono‐, and non‐ortho PCBs into three fractions for gas chromatography (GC)/electron capture detection analysis, and a fourth fraction containing the PCDDs/PCDFs for GC/mass spectrometry analysis. The recoveries of the PCBs ranged from 68 to 96%, and recoveries of the PCDDs/PCDFs ranged from 74 to 123%. The PGC column has the advantage of faster separations (110 min versus 446 min) and less solvent use (275 ml versus 1,100 ml) compared with automated fractionation of these compounds on activated carbon (PX‐21), while still affording good separation of the classes. The PGC column may have an advantage over the pyrenyl‐based HPLC method because it has a greater loading capacity (400 μg total PCBs versus 250 μg). Overall, the PGC is a standard column that provides reproducible fractionation of PCDD/PCDFs and PCBs for analytical measurement in environmental samples.

Seasonal Fluctuation of Promoters and Inhibitors of Adventitious Root Formation in `Nabali' Olive Shoots

Four fractions from known dry weights from buds or leaves of `Nabali' olive shoots—nonacidic ethylacetate (F 1), acidic ether (F 2) and acidic-n-butanol (F 3) were obtained for several sampling dates. A fourth fraction (F 4) from F 1, F 2, and F 3 was established. The four crude fractions were bioassayed for adventitious root formation using mung bean cuttings. In another extraction, fractionation by paper chromatography was performed to identify promoters and inhibitors using the Rf values and mung bean bioassay. The results indicated absence of rooting inhibitors in buds and leaves of `Nabali' olive in mung bean bioassay in all four crude extracts and their fractions located at the various Rf values. However, rooting promoters from buds and leaves were detected by mung bean bioassay in all crude extracts. F 1 contained rooting promoters located at Rf 0.5 and 0.6 throughout the period from 20 Nov. to 2 Apr.; these promoters were found to be highest in buds sampled 23 Feb. and in leaves sampled 4 Dec. and 4 Feb. F 2 from buds and leaves showed neither promoting nor inhibitory activities. F 3 (from leaves or buds) contained promoters of rooting located at Rfs from -.4–0.7 throughout the sampling periods. However, F 3 from buds on 9 Dec., 23 Feb., and 2 Apr.; and from leaves on 4 Feb. gave significantly highest root-promoting activity. F 4 from buds and leaves showed root-promoting effects from November to April. The promoting effect of F 4 was greatest in buds and leaves sampled 9 Dec. and 4 Feb., respectively.

The critical molecular weight for resisting slow crack growth in a polyethylene

An ethylene-hexene copolymer was fractionated into five fractions and the density of short-chain branches was measured for each fraction. The slow crack growth behavior was measured on each fraction by sandwiching the small amount of fractionated resin of about 0.2 g between polyethylene grips. The resistance to slow crack growth was negligible for the three fractions whose Mw was less than 1.5 × 105. For the fourth fraction with Mw greater than 1.5 × 105, the resistance to slow crack growth was very high, being greater than that for the whole resin even though its density of short-chain branches was less than that of the whole resin. It is concluded that a molecular weight greater than 1.5 × 105 is required to create the number of tie molecules that is necessary to produce a high resistance to slow crack growth in this particular copolymer. © 1996 John Wiley & Sons, Inc.

A dextran swim-up procedure for separation of highly motile and viable ram spermatozoa from seminal plasma

Although washing of sperm cells by centrifugation is a procedure in widespread use, there have been indications that centrifugation may be harmful to the cells. The objective of this study was to develop a modified swim-up technique, without centrifugation, to get a selection of highly motile and viable ram spermatozoa free of semen plasma. Semen collected from 3 rams over a period of a year was pooled into a low, medium and high motility group, and aliquots from each pool were placed beneath a dextran solution and overlaid with medium. The top layer of the medium was collected (and replenished) 4 times at 15-min intervals. Evaluated were the pre- and post-swim-up progressive individual motility, membrane integrity and resistance to a hypoosmotic swelling test (HOS). Semen samples with initial motility < 60% showed the highest relative improvement in all 3 parameters; samples with 65 to 70 and > 70% initial motility improved less but showed final absolute values similar to those in the low motility group and to each other. The first swim-up layer had the highest contamination with semen plasma (17% beta-N-acetylglucosaminidase (NAG), 13% citric acid content) and the lowest motility score. The second, third and fourth fractions were pooled and showed low plasma contamination (2% NAG and 5% citrate), 80% motility, 70% HOS, and 72% viability, up from the pre-swim-up values of 68, 66 and 59%, respectively. Our data suggest that the dextran swim-up procedure is suitable for evaluating ram spermatozoa for in vitro and in vivo procedures in assisted reproduction.