Gas emission during laparoscopic colorectal surgery using a bipolar vessel sealing device: A pilot study on four patients.

BACKGROUND: Dissection during laparoscopic surgery produces smoke containing potentially toxic substances. The aim of the present study was to analyze smoke samples produced during laparoscopic colon surgery using a bipolar vessel sealing device (LigaSuretrade mark). METHODS: Four consecutive patients undergoing left-sided colectomy were enrolled in this pilot study. Smoke was produced by the use of LigaSuretrade mark. Samples (5,5l) were evacuated from the pneumoperitoneum in a closed system into a reservoir. Analysis was performed with CO2-laser-based photoacoustic spectroscopy and confirmed by a Fourier-transform infrared spectrum. The detected spectra were compared to the available spectra of known toxins. RESULTS: Samples from four laparoscopic sigmoid resections were analyzed. No relevant differences were noted regarding patient and operation characteristics. The gas samples were stable over time proven by congruent control measurements as late as 24 h after sampling. The absorption spectra differed considerably between the patients. One broad absorption line at 100 ppm indicating H2O and several unknown molecules were detected. With a sensitivity of alpha min ca 10-5 cm-1 no known toxic substances like phenol or indole were identified. CONCLUSION: The use of a vessel sealing device during laparoscopic surgery does not produce known toxic substances in relevant quantity. Further studies are needed to identify unknown molecules and to analyze gas emission under various conditions.

Chemical profiling of different hashish seizures by gas chromatography-mass spectrometry and statistical methodology: a case report

Limited information is available regarding the methodology required to characterize hashish seizures for assessing the presence or the absence of a chemical link between two seizures. This casework report presents the methodology applied for assessing that two different police seizures were coming from the same block before this latter one was split. The chemical signature was extracted using GC-MS analysis and the implemented methodology consists in a study of intra- and inter-variability distributions based on the measurement of the chemical profiles similarity using a number of hashish seizures and the calculation of the Pearson correlation coefficient. Different statistical scenarios (i.e., a combination of data pretreatment techniques and selection of target compounds) were tested to find the most discriminating one. Seven compounds showing high discrimination capabilities were selected on which a specific statistical data pretreatment was applied. Based on the results, the statistical model built for comparing the hashish seizures leads to low error rates. Therefore, the implemented methodology is suitable for the chemical profiling of hashish seizures.

Determination of human plasma levels of levo-alpha-acetylmethadol and its metabolites by gas chromatography-mass spectrometry.

A gas chromatography-mass spectrometry (GC-MS) method is presented which allows the simultaneous determination of the plasma concentrations of the levo-alpha-acetylmethadol (LAAM) and of its active metabolites (NorLAAM and DiNorLAAM), after derivatization with the reagent trifluoroacetic anhydride (TFAA). No interferences from endogenous compounds were observed following the extraction of plasma samples from 11 different human subjects. The standard curves were linear over a working range of 5-200ng/ml for the three compounds. Recoveries measured at three concentrations ranged from 47 to 67% for LAAM, from 50 to 69% for NorLAAM and from 28 to 50% for DiNorLAAM. Intra- and interday coefficients of variation determined at three concentrations ranged from 5 to 13% for LAAM, from 3 to 9% for NorLAAM and from 5 to 13% for DiNorLAAM. The limits of quantitation of the method were found to be 4ng/ml for the three compounds. No interference was noted from methadone. This sensitive and specific analytical method could be useful for assessing the in vivo relationship between LAAM's blood levels, clinical efficacy and/or cardiotoxicity

Monitorització de rendiment i accounting de centres de computació grid

El Port d'Informació Científica és un centre de Computació Grid de referència que dona suport a comunitats científiques, com el LHC (CERN). Al PIC, trobem una gran varietat de tecnologies que proporcionen serveis al centre. Des de l'arquitectura i elements de la xarxa, fins a recursos informàtics de computació, sistemes d'emmagatzematge a disc i cinta magnètica, bases de dades (ORACLE/PostgreSQL). El projecte consisteix en el disseny i implementació d'una base de dades col·lectora de tota la informació rellevant dels diferents sistemes del centre, i un portal web on mostrar tots els valors i gràfiques, tot basat en programari lliure.

Expansion of intraocular gas bubbles due to altitude: do meteorological factors play a role?

BACKGROUND: Intraocular gas bubbles expand as patients move up to higher altitude. This may cause an acute intraocular pressure (IOP) rise with associated vascular obstructions and visual loss. MATERIALS AND METHODS: Two pseudophakic patients underwent a pars plana vitrectomy and 23% SF6 gas tamponade for a pseudophakic retinal detachment. During the immediate post-operative phase, the patients travelled daily up to their domicile, which was situated approximately 600 m higher than the level where they had been operated on. These travels were always without any pain or visual loss. However 1 week after surgery both patients developed severe ocular pain, and one patient had complete temporary loss of vision after ascending to altitude levels, which had previously presented no problem. Both episodes occurred in parallel with a change in barometric pressure. RESULTS: Treatment with acetazolamide reduced the increased IOP to normal levels, and visual acuity recovered. CONCLUSIONS: Although the post-operative size of an intraocular gas bubble decreases progressively over time, problems with bubble expansion may still occur even at a late stage if meteorological factors, that may increase the bubble size, change.

Variation in cuticular hydrocarbons among strains of the Anopheles gambiae sensu stricto by analysis of cuticular hydrocarbons using gas liquid chromatography of larvae

Cuticular hydrocarbons of larvae of individual strains of the Anopheles gambiae sensu stricto were investigated using gas liquid chromatography. Biomedical discriminant analysis involving multivariate statistics suggests that there was clear hydrocarbon difference between the Gambian(G3), the Nigerian (16CSS and, its malathion resistant substrain, REFMA) and the Tanzanian (KWA) strains. The high degree of segregation (95%) in hydrocarbons among the four strains investigated indicates that further analysis is needed to enable understanding of hydrocarbon variation in samples of An. gambiae especially from areas where these populations co-exist.

An efficient use of virtualization in grid/cloud environments

Grid is a hardware and software infrastructure that provides dependable, consistent, pervasive, and inexpensive access to high-end computational resources. Grid enables access to the resources but it does not guarantee any quality of service. Moreover, Grid does not provide performance isolation; job of one user can influence the performance of other user’s job. The other problem with Grid is that the users of Grid belong to scientific community and the jobs require specific and customized software environment. Providing the perfect environment to the user is very difficult in Grid for its dispersed and heterogeneous nature. Though, Cloud computing provide full customization and control, but there is no simple procedure available to submit user jobs as in Grid. The Grid computing can provide customized resources and performance to the user using virtualization. A virtual machine can join the Grid as an execution node. The virtual machine can also be submitted as a job with user jobs inside. Where the first method gives quality of service and performance isolation, the second method also provides customization and administration in addition. In this thesis, a solution is proposed to enable virtual machine reuse which will provide performance isolation with customization and administration. The same virtual machine can be used for several jobs. In the proposed solution customized virtual machines join the Grid pool on user request. Proposed solution describes two scenarios to achieve this goal. In first scenario, user submits their customized virtual machine as a job. The virtual machine joins the Grid pool when it is powered on. In the second scenario, user customized virtual machines are preconfigured in the execution system. These virtual machines join the Grid pool on user request. Condor and VMware server is used to deploy and test the scenarios. Condor supports virtual machine jobs. The scenario 1 is deployed using Condor VM universe. The second scenario uses VMware-VIX API for scripting powering on and powering off of the remote virtual machines. The experimental results shows that as scenario 2 does not need to transfer the virtual machine image, the virtual machine image becomes live on pool more faster. In scenario 1, the virtual machine runs as a condor job, so it easy to administrate the virtual machine. The only pitfall in scenario 1 is the network traffic.

PHA urges 'freshers' to be smart and know their alcohol limits

As 'fresher's week' commences, the Public Health Agency is encouraging students across Northern Ireland to avoid binge drinking and to know their limits if they do choose to drink alcohol.Enjoying new freedoms, at college or university, means taking care of yourself and others and, if you choose to drink, staying within safe alcohol limits. Owen O'Neill, PHA Health and Social Wellbeing Improvement Manager for drugs and alcohol, said: "Some young people may drink more when they leave home, or join their friends in college or university for the first time. They might think that, as young people, they don't have to take care with alcohol, but staying within the safe drinking limits is important for everyone who drinks. Excessive and binge drinking can have lasting effects on health, such as damage to the liver, heart, brain and stomach. Drinking too much can also increase the risk of accidents and antisocial behaviour as well as sexually transmitted infections and unplanned pregnancy"."We would also strongly advise against drinking games. Although they are regarded as a 'bit of fun', in reality they can be very dangerous. As an extreme form of binge drinking, where large quantities of alcohol are consumed in a very short time, drinking games can result in alcohol poisoning, leading to brain damage, coma or death. The PHA encourages students to enjoy their new student life, but urges them to be aware of their alcohol intake and drink responsibly, especially throughout fresher's week, with the many cheap drink promotions currently available."Daily alcohol limits are recommended by the government in order to avoid the risks of excessive and binge drinking in any one session. These are:Men: No more than 3 to 4 units of alcohol a day and no more than 21 units over the course of the week.Women: No more than 2 to 3 units of alcohol a day and no more than 14 units over the course of the week.Examples of units:Can of extra strong lager - 4 unitsBottle of lager - 1.5 unitsPint of standard lager - 2.5 unitsPint of premium larger - 3 unitsSmall pub bottle of wine - 2.25 units70cl bottle of wine - 7 to 10 unitsStandard 275ml of alcopops - 1.5 to 1.8 units70cl bottle of alcopops - 3.75 to 4.5 unitsPub measure of spirits - 1.5 unitsPint of cider - 3 unitsPint of stout - 2.5 unitsIf you do choose to drink alcohol:DON'T:Ever drink and driveDrink on an empty stomachMix alcohol with other drugsDrink in rounds as this may speed up your drinkingLeave your drinks unattendedDO:Take sips rather than gulpsAlternate each alcoholic drink with a non alcoholic drink e.g. water or a soft drinkSet yourself a limit and try to stick to it (refer to daily alcohol limits) Take frequent breaks from drinking to give your body time to recoverTell friends and family where you are going and who you will be withRemember, that for each unit you drink over the daily limit, the risk to your health increases. It's important to spread the units throughout the week - you can't 'save up' your units for the weekend or your holiday. It is also important to drink plenty of water, ideally matching the amount of alcohol you have consumed.So students make smart choices this term - drink sensibly and know your limits!For further information on sensible drinking and alcohol units visit the Public Health Agency's website www.knowyourlimits.info

A New Year's Resolution - be smart about your drinking!

Now 2012 has arrived, the Public Health Agency is encouraging people to make a New Year's resolution to know their limits when it comes to alcohol, not to drink excessively and to cut back for a while, especially if the festive period led to a little too much consumption.Owen O'Neill, PHA Health and Social Wellbeing Improvement Manager and drugs and alcohol lead, explained: "The New Year is a great opportunity for us to be positive about our health, making resolutions that make us look and feel better. If people choose to drink, staying within the safe drinking limits is important. Excessive and binge drinking can have lasting effects on health, such as damage to the liver, heart, brain and stomach. Drinking too much can also increase the risk of accidents and antisocial behaviour as well as sexually transmitted infections and unplanned pregnancy. And it doesn't have to be drinking to extremes - regularly drinking over the recommended limits can have a damaging effect."Remember that for each unit you drink over the daily limit, the risk to your health increases. It's important to spread the units throughout the week and not 'save' them for the weekend and to drink plenty of water, ideally matching the amount of alcohol you have consumed."For those who have consumed a lot of alcohol over the festive season, cutting back in the New Year and being careful can have immediate, positive effects particularly on helping you to look and feel better, being less tired during the day, feeling fitter and perhaps losing weight. Longer term, the benefits include improved mood, sleep, memory and general health, particularly improving liver function, immunity to illness and preventing any damage caused by any excessive drinking getting any worse."Daily alcohol limits are recommended by the government to avoid the dangers of excessive and binge drinking in any one session. These are:MenNo more than 3 to 4 units of alcohol a day and no more than 21 units over the course of the week.WomenNo more than 2 to 3 units of alcohol a day and no more than 14 units over the course of the week.Examples of units:Can of extra strong lager - 4 unitsBottle of lager - 1.5 unitsSmall pub bottle of wine - 2.25 unitsPub measure of spirits - 1.5 unitsPint of stout - 2.5 unitsPint of cider - 3 unitsFor further information on sensible drinking and alcohol units visit the Public Health Agency's website www.knowyourlimits.info

Carbon isotopic ratio analysis by gas chromatography/combustion/isotope ratio mass spectrometry for the detection of gamma-hydroxybutyric acid (GHB) administration to humans.

Since GHB (gamma-hydroxybutyric acid) is naturally produced in the human body, clinical and forensic toxicologists must be able to discriminate between endogenous levels and a concentration resulting from exposure. To suggest an alternative to the use of interpretative concentration cut-offs, the detection of exogenous GHB in urine specimens was investigated by means of gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). GHB was isolated from urinary matrix by successive purification on Oasis MCX and Bond Elute SAX solid-phase extraction (SPE) cartridges prior to high-performance liquid chromatography (HPLC) fractioning using an Atlantis dC18 column eluted with a mixture of formic acid and methanol. Subsequent intramolecular esterification of GHB leading to the formation of gamma-butyrolactone (GBL) was carried out to avoid introduction of additional carbon atoms for carbon isotopic ratio analysis. A precision of 0.3 per thousand was determined using this IRMS method for samples at GHB concentrations of 10 mg/L. The (13)C/(12)C ratios of GHB in samples of subjects exposed to the drug ranged from -32.1 to -42.1 per thousand, whereas the results obtained for samples containing GHB of endogenous origin at concentration levels less than 10 mg/L were in the range -23.5 to -27.0 per thousand. Therefore, these preliminary results show that a possible discrimination between endogenous and exogenous GHB can be made using carbon isotopic ratio analyses.