4,028 research outputs found
Staged and non-staged anaerobic filters : microbial activity segregation, hydrodynamic behaviour and performance
This work describes a comparative study of staged and non-staged anaerobic flters for treating a synthetic dairy waste under similar operating conditions.
The effect of increasing the substrate concentration from 3 to 12 g COD dmˉ³ at a constant hydraulic residence time (HRT) of 2 days was evaluated with
respect to overall reactor performance, biogas production, volatile fatty acids
profiles along the height, methanogenic and acidogenic activity distribution, and
hydrodynamic behaviour. The potential maximum specific methanogenic activity
against acetate, hydrogen, propionate and butyrate and the lactose specific activity
were determined for sludge sampled from three different points in each
reactor, under two operating conditions (influent COD of 3 and 9 g COD
dmˉ³). Although all trophic groups involved in the anaerobic process were
found throughout the reactors, it was possible to identify different specific
sludges at different heights in both reactors. Performances of the two configurations
were very similar under the operating conditions tested and the plug flow
behaviour of the staged reactor was clearly reduced when the influent concentration
increased from 3 to 9 g COD dmˉ³.EU Human Capital and Mobility network Improved Application of Anaerobic
Digestion Technology - EXBCHRXCT 930262.Fundação para a Ciência e a Tecnologia – PEAM/SEL/517/95
The effect of cigarette price increase on the cigarette consumption in Taiwan: evidence from the National Health Interview Surveys on cigarette consumption
BACKGROUND: This study uses cigarette price elasticity to evaluate the effect of a new excise tax increase on cigarette consumption and to investigate responses from various types of smokers. METHODS: Our sample consisted of current smokers between 17 and 69 years old interviewed during an annual face-to-face survey conducted by Taiwan National Health Research Institutes between 2000 to 2003. We used Ordinary Least Squares (OLS) procedure to estimate double logarithmic function of cigarette demand and cigarette price elasticity. RESULTS: In 2002, after Taiwan had enacted the new tax scheme, cigarette price elasticity in Taiwan was found to be -0.5274. The new tax scheme brought about an average annual 13.27 packs/person (10.5%) reduction in cigarette consumption. Using the cigarette price elasticity estimate from -0.309 in 2003, we calculated that if the Health and Welfare Tax were increased by another NT$ 3 per pack and cigarette producers shifted this increase to the consumers, cigarette consumption would be reduced by 2.47 packs/person (2.2%). The value of the estimated cigarette price elasticity is smaller than one, meaning that the tax will not only reduce cigarette consumption but it will also generate additional tax revenues. Male smokers who had no income or who smoked light cigarettes were found to be more responsive to changes in cigarette price. CONCLUSIONS: An additional tax added to the cost of cigarettes would bring about a reduction in cigarette consumption and increased tax revenues. It would also help reduce incidents smoking-related illnesses. The additional tax revenues generated by the tax increase could be used to offset the current financial deficiency of Taiwan's National Health Insurance program and provide better public services
Thermal production of axino Dark Matter
We reconsider thermal production of axinos in the early universe, adding: a)
missed terms in the axino interaction; b) production via gluon decays
kinematically allowed by thermal masses; c) a precise modeling of reheating. We
find an axino abunance a few times larger than previous computations.Comment: 6 pages, 2 figures. Final version, to appear on JHE
Accelerated in vivo proliferation of memory phenotype CD4+ T-cells in human HIV-1 infection irrespective of viral chemokine co-receptor tropism.
CD4(+) T-cell loss is the hallmark of HIV-1 infection. CD4 counts fall more rapidly in advanced disease when CCR5-tropic viral strains tend to be replaced by X4-tropic viruses. We hypothesized: (i) that the early dominance of CCR5-tropic viruses results from faster turnover rates of CCR5(+) cells, and (ii) that X4-tropic strains exert greater pathogenicity by preferentially increasing turnover rates within the CXCR4(+) compartment. To test these hypotheses we measured in vivo turnover rates of CD4(+) T-cell subpopulations sorted by chemokine receptor expression, using in vivo deuterium-glucose labeling. Deuterium enrichment was modeled to derive in vivo proliferation (p) and disappearance (d*) rates which were related to viral tropism data. 13 healthy controls and 13 treatment-naive HIV-1-infected subjects (CD4 143-569 cells/ul) participated. CCR5-expression defined a CD4(+) subpopulation of predominantly CD45R0(+) memory cells with accelerated in vivo proliferation (p = 2.50 vs 1.60%/d, CCR5(+) vs CCR5(-); healthy controls; P<0.01). Conversely, CXCR4 expression defined CD4(+) T-cells (predominantly CD45RA(+) naive cells) with low turnover rates. The dominant effect of HIV infection was accelerated turnover of CCR5(+)CD45R0(+)CD4(+) memory T-cells (p = 5.16 vs 2.50%/d, HIV vs controls; P<0.05), naïve cells being relatively unaffected. Similar patterns were observed whether the dominant circulating HIV-1 strain was R5-tropic (n = 9) or X4-tropic (n = 4). Although numbers were small, X4-tropic viruses did not appear to specifically drive turnover of CXCR4-expressing cells (p = 0.54 vs 0.72 vs 0.44%/d in control, R5-tropic, and X4-tropic groups respectively). Our data are most consistent with models in which CD4(+) T-cell loss is primarily driven by non-specific immune activation
Scintillator-based ion beam profiler for diagnosing laser-accelerated ion beams
Next generation intense, short-pulse laser facilities require new high repetition rate diagnostics for the detection of ionizing radiation. We have designed a new scintillator-based ion beam profiler capable of measuring the ion beam transverse profile for a number of discrete energy ranges. The optical response and emission characteristics of four common plastic scintillators has been investigated for a range of proton energies and fluxes. The scintillator light output (for 1 MeV > Ep < 28 MeV) was found to have a non-linear scaling with proton energy but a linear response to incident flux. Initial measurements with a prototype diagnostic have been successful, although further calibration work is required to characterize the total system response and limitations under the high flux, short pulse duration conditions of a typical high intensity laser-plasma interaction
Evaluation of the Osteogenic Potential of Growth Factorâ Rich Demineralized Bone Matrix In Vivo
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141502/1/jper0036.pd
Switching Virally Suppressed, Treatment-Experienced Patients to a Raltegravir-Containing Regimen Does Not Alter Levels of HIV-1 DNA
Background: Current HIV-1 antiretroviral therapy (ART) greatly reduces virus replication but does not significantly affect the viral reservoir. Raltegravir, a recently introduced integrase inhibitor, could, at least theoretically, reduce residual viremia in patients on ART and affect the viral reservoir size. The aim of this study was to assess whether switching therapy in treatment-experienced patients that were virally suppressed to a raltegravir-containing regimen reduces the size of the viral reservoir, and if such treatment leads to a change in levels of HIV 2-LTR circles in this patient group. Methods: 14 ART experienced individuals with a suppressed viral load (,50 HIV-1 RNA copies/mL plasma) at baseline (for at least 2 months) were switched to a raltegravir-containing regimen. Blood samples were taken at baseline and at $2 timepoints up to 4866 weeks. Levels of total HIV-1 DNA and 2-LTR circles in peripheral blood mononuclear cells (PBMCs) were measured using real-time PCR assays. Results: There was no significant change in HIV-1 total DNA levels over the study duration (p = 0.808), median slope 0.24 (conservative nonparametric 95 % CI: 211.78, 26.23). Low levels of 2-LTR circles were detected in 2 patients. One had 16 copies/10 6 PBMCs at baseline and the other had 34 copies/10 6 PBMCs at week 51. Conclusions: The switch to a raltegravir containing regimen was not associated with a significant change in HIV-1 total DNA levels in this cohort. There were no observed changes in the levels of HIV-1 2-LTR circles associated with raltegravi
Lack of Detectable HIV-1 Molecular Evolution during Suppressive Antiretroviral Therapy
A better understanding of changes in HIV-1 population genetics with combination antiretroviral therapy (cART) is critical for designing eradication strategies. We therefore analyzed HIV-1 genetic variation and divergence in patients' plasma before cART, during suppression on cART, and after viral rebound. Single-genome sequences of plasma HIV-1 RNA were obtained from HIV-1 infected patients prior to cART (N = 14), during suppression on cART (N = 14) and/or after viral rebound following interruption of cART (N = 5). Intra-patient population diversity was measured by average pairwise difference (APD). Population structure was assessed by phylogenetic analyses and a test for panmixia. Measurements of intra-population diversity revealed no significant loss of overall genetic variation in patients treated for up to 15 years with cART. A test for panmixia, however, showed significant changes in population structure in 2/10 patients after short-term cART (<1 year) and in 7/10 patients after long-term cART (1-15 years). The changes consisted of diverse sets of viral variants prior to cART shifting to populations containing one or more genetically uniform subpopulations during cART. Despite these significant changes in population structure, rebound virus after long-term cART had little divergence from pretherapy virus, implicating long-lived cells infected before cART as the source for rebound virus. The appearance of genetically uniform virus populations and the lack of divergence after prolonged cART and cART interruption provide strong evidence that HIV-1 persists in long-lived cells infected before cART was initiated, that some of these infected cells may be capable of proliferation, and that on-going cycles of viral replication are not evident
Severe sepsis caused by Aeromonas hydrophila in a patient using tocilizumab: a case report
<p>Abstract</p> <p>Introduction</p> <p><it>Aeromonas </it>species do not commonly cause disease in humans. However, when disease is seen, it often occurs in patients with underlying immunosuppression or malignancy and has a high fatality rate.</p> <p>Case presentation</p> <p>A 72-year-old Japanese woman with rheumatoid arthritis treated with tocilizumab (which has an immunosuppressive effect) presented with severe epigastric pain. She had a fever with chills, hypotension and jaundice. She was diagnosed with acute suppurative cholangitis and treated with cefoperazone-sulbactam and an endoscopic drainage was performed. Jaundice was slightly improved, but the shock state and inflammatory reactions were prolonged as typical of septic shock. On the second day after admission, an electrocardiogram showed ST segment elevation and echocardiography showed ventricular wall dysfunction. Coronary arteries were patent in coronary angiography and she was diagnosed with stress-induced cardiomyopathy. Blood cultures showed <it>Aeromonas hydrophila</it>. A stool culture was negative for <it>A. hydrophila</it>. On day six, her white blood cell count and neutrophils were normalized and cefoperazone-sulbactam treatment was halted. Left ventricular function normalized on day twelve and a laparoscopic cholecystectomy for cholelithiasis was performed on the 16th day of hospitalization. A culture from the bile showed <it>A. hydrophila</it>. Eighteen days after surgery, tocilizumab treatment was restarted and there were no complications. Two months after restarting tocilizumab, our patient is stable without any serious events.</p> <p>Conclusion</p> <p>We present a rare case of <it>A. hydrophila </it>sepsis and acute suppurative cholangitis in an elderly patient with gallstones and rheumatoid arthritis using tocilizumab. This clinical course may suggest that preemptive treatment for cholelithiasis prior to using molecular-targeting agents might be feasible in elderly patients.</p
Development of a LAMP assay for detection of Leishmania infantum infection in dogs using conjunctival swab samples
Background: Leishmania infantum infections in dogs play a crucial role in the transmission of pathogens causing visceral leishmaniasis to humans in the Gansu province, northwest China. To be able to control zoonotic transmission of the parasite to humans, a non-invasive loop-mediated isothermal amplification (LAMP) assay to specifically detect L. infantum infections in dogs was developed. Methods: The primers used in the LAMP assay were designed to target kinetoplast DNA minicircle sequences of the L. infantum isolate MCAN/CN/90/SC and tested using DNA isolated from promastigotes of different Leishmania species. The LAMP assay was evaluated with conjunctional swab samples obtained from 111 and 33 dogs living in an endemic and a non-endemic region of zoonotic visceral leishmaniasis in the Gansu province, respectively. The LAMP assay was also compared with conventional PCR, ELISA and microscopy using conjunctional swab, serum and bone marrow samples from the dogs, respectively. Results: The LAMP assay detected 1 fg of L. infantum DNA purified from cultured promastigotes which was 10-fold more sensitive than a conventional PCR test using Leishmania genus-specific primers. No cross reaction was observed with DNA isolated from promastigotes of L. donovani, L. major, L. tropica, and L. braziliensis, and the L. infantum reference strain MHOM/TN/80/IPT1. The L. infantum-positive rates obtained for field-collected samples were 61.3%, 58.6%, 40.5% and 10.8% by LAMP, PCR, ELISA and microscopy, respectively. As only one out of the 33 samples from control dogs from the non-endemic region of zoonotic visceral leishmaniasis was positive by the LAMP assay and the PCR test, the observed true negative rate (specificity) was 97% for both methods. Conclusion: This study has shown that the non-invasive, conjunctional swab-based LAMP assay developed was more sensitive in the detection of leishmaniasis in dogs than PCR, ELISA and microscopy. The findings indicate that the LAMP assay is a sensitive and specific method for the field surveillance of domestic dogs, particularly of asymptomatic canines, in ZVL-endemic areas in western China
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