Effet de différents systèmes de culture à couverture végétale sur le stockage du carbone dans un sol argileux des Hautes Terres de Madagascar

Stocker du carbone dans le sol permet d'améliorer ses propriétés physico-chimiques et de réduire les émissions de dioxyde de carbone vers l'atmosphère. L'effet des systèmes en semis direct avec couverture végétale (SCV) sur le stockage de C dans le sol est étudié sur un dispositif agronomique de longue durée (11 ans) à Antsirabe, Madagascar (16°C, 1 300 mm). Quatre systèmes sont étudiés: un système en labour conventionnel avec exportation des résidus de récolte [CT m/s, rotation maïs (Zea mays L.)-soja (Glycine max. L.)], et trois systèmes en SCV sans travail du sol, et avec restitution des résidus de récolte [NT m/s, rotation maïs-soja; NT m/m-d, rotation maïs-maïs avec une couverture végétale de Desmodium uncinatum; et NT h/s-k, rotation haricot (Phaseolus vulgaris)-soja avec une couverture végétale de Pennissetum clandestinum]. Le sol est très argileux, à faible capacité d'échange cationique mais possédant des propriétés andiques pouvant influencer les potentialités de stockage du C du sol. A 0-5 cm, les teneurs en C sont plus élevées sous SCV (NT m/s, NT m/m-d et NT his) que sous labour (CT m/s), et à 5-10 cm, elles sont plus élevées sous NT m/m-d et NT m/s que sous NT h/s-k et CT m/s. Le stockage annuel de C, à masse de sol équivalente, est de 0,69 et 1,01 mg C.ha-1.an-1, sous NT m/s et NT m/m-d pour l'horizon équivalent à 0-20 cm, alors qu'il n'y a pas d'effet SCV observé pour l'horizon équivalent à 0-40 cm. Ceci peut être dû à la fois à l'absence réelle de stockage comme à une variabilité initiale des teneurs en C dans les horizons de profondeurs, car le labour n'est effectué que jusqu'à 20 cm de profondeur. Les différences de stockage de C entre NT et CT dans la couche 0-20 cm sont essentiellement attribuées aux quantités beaucoup plus importantes de résidus organiques restituées par les systèmes NT par rapport au système labouré CT, mais on peut aussi envisager qu'une partie de cette différence soit le fait d'une perte de C par érosion sous labour. Les teneurs en macroagrégats stables (MA, 200-2 000 [mu]m) sont plus élevées sous NT m/s, NT h/s-k et NT m/m-d que sous CT m/s à 0-5 cm et à 5-10 cm. Cette teneur en MA est corrélée positivement (R = 0,408, p < 0,05, n = 24) avec la teneur en C du sol, ce qui pourrait induire (i) une amélioration de l'agrégation en fonction de l'augmentation de la teneur en C du sol et (ii) une protection du C se trouvant à l'intérieur de ces agrégats contre la minéralisation microbienne. Toutefois, la respirométrie ne montre pas une protection physique de C dans les sites de protection supérieurs à 200 [mu]m pour NT m/s et CT m/s. Dans cette étude, le C stocké dans le sol pourrait alors être protégé contre la minéralisation par d'autres processus comme l'adsorption sur les colloïdes du sol ou la recalcitrance biochimique de la matière organique du sol. (Résumé d'auteur

Реологічні дослідження основи гелю з густим екстрактом лопуха

A rapid development of civilization and deterioration of the ecological condition of the environment lead to increase in allergic diseases. The studies conducted in several regions ofUkrainehave shown that in industrial centers 10–20 % of the population suffer from allergic diseases, and only 2–4 % in rural areas. To solve the problems researchers and practical surgeons pay more attention to drugs of the natural origin containing a significant number of biologically active compounds, some of them are with the reparative and anti-inflammatory activity.Aim. To conduct the studies in developing the gel composition containing a dense extract from burdock for its use in dermatology.Materials and methods. Development of a new drug is based on the general methodological approach to pharmaceutical development taking into account the requirements for a dosage form. To assess the structural and mechanical properties of the gel developed the rheological parameters were determined using a Rheolab QC rotary viscometer (Anton Paar,Austria) with coaxial cylinders CC27/S-SN29766.Results. The concentration of hydroxymethylcellulose (2 %) has been determined; it provides the structural and mechanical properties required for the gel base. It has been determined that the gel base with hydroxymethyl cellulose (HMC) refers to non-newtonian flow types with plastic properties and has thixotropy. The calculated value of the HMC gel base allows predicting stability in homogenization and storage of the finished drug.Conclusions. The rheological parameters of the gel with the burdock extract on the HMC base have been studied.Стремительное развитие цивилизации, ухудшение экологического состояния окружающей среды приводят к росту аллергических заболеваний. Проведенные в ряде районов Украины исследования показали, что в промышленных центрах аллергическими болезнями страдают от 10 до 20 % населения, а в сельской местности – всего 2-4 %. Для решения поставленных задач исследователи и практические хирурги все чаще обращают внимание на лекарственные препараты природного происхождения, содержащие значительное количество биологически активных соединений, часть которых имеет репаративную и противовоспалительную активность.Цель: исследования по разработке состава геля, содержащего густой экстракт лопуха, для применения в дерматологии.Материалы и методы. Разработка нового лекарственного средства основываться на общем методологическом подходе к фармацевтической разработке с учетом требований к лекарственной форме. Для оценки структурно-механических свойств разработанного геля определяли реологические показатели с помощью ротационного вискозиметра «Rheolab QC» (фирма «Anton Paar», Австрия) с коаксиальными цилиндрами CC27/S-SN29766.Результаты исследования. Определена концентрация гидроксиметилцеллюлозы – 2 %, которая обеспечивает необходимые структурно-механические свойства гелевой основы. Установлено, что гелевая основа с ГМЦ относится к неньютоновским типам течения с пластическими свойствами и имеет тиксотропность. Рассчитанное значение МС гелевой основы позволяет прогнозировать стабильность при гомогенизации и хранении готового лекарственного средства.Выводы. Исследованы реологические показатели геля с экстрактом лопуха на основе гидроксиметилцеллюлозы. Стрімкий розвиток цивілізації, погіршення екологічного стану навколишнього середовища призводять до росту алергічних захворювань. Проведені в деяких районах України дослідження показали, що в промислових центрах на алергічні хвороби страждають від 10 до 20 % населення, а в сільській місцевості – лише 2–4 %. Для вирішення поставлених завдань дослідники і практичні хірурги все частіше звертають увагу на лікарські препарати природного походження, що містять значну кількість біологічно активних сполук, частина яких має репаративну та протизапальну активність.Мета: дослідження з розробки складу гелю для застосування в дерматології, що містить густий екстракт лопуха. Матеріали та методи. Розробка нового лікарського засобу ґрунтувалася на загальному методологічному підході до фармацевтичної розробки з урахуванням вимог до лікарської форми. Для оцінки структурно-механічних властивостей розробленого гелю визначали реологічні показники за допомогою ротаційного віскозиметра «Rheolab QC» (фірма «Anton Paar», Австрія) з коаксіальними циліндрами CC27/S-SN29766.Результати дослідження. Визначена концентрація гідроксиметилцелюлози – 2 %, яка забезпечує необхідні структурно-механічні властивості гелевої основи. Встановлено, що гелева основа з ГМЦ належить до неньютонівських типів течії з пластичними властивостями і має тиксотропність. Розраховане значення МС гелевої основи дозволяє прогнозувати стабільність при гомогенізації та зберіганні готового лікарського засобу.Висновки. Досліджено реологічні показники гелю з екстрактом лопуха на основі гідроксиметилцелюлози

Increased Mucosal Thrombin is Associated with Crohn's Disease and Causes Inflammatory Damage through Protease-activated Receptors Activation

Background and Aims: Thrombin levels in the colon of Crohn's disease patients have recently been found to be elevated 100-fold compared with healthy controls. Our aim was to determine whether and how dysregulated thrombin activity could contribute to local tissue malfunctions associated with Crohn's disease. Methods: Thrombin activity was studied in tissues from Crohn's disease patients and healthy controls. Intracolonic administration of thrombin to wild-type or protease-activated receptor-deficient mice was used to assess the effects and mechanisms of local thrombin upregulation. Colitis was induced in rats and mice by the intracolonic administration of trinitrobenzene sulphonic acid. Results: Active forms of thrombin were increased in Crohn's disease patient tissues. Elevated thrombin expression and activity were associated with intestinal epithelial cells. Increased thrombin activity and expression were also a feature of experimental colitis in rats. Colonic exposure to doses of active thrombin comparable to what is found in inflammatory bowel disease tissues caused mucosal damage and tissue dysfunctions in mice, through a mechanism involving both protease-activated receptors -1 and -4. Intracolonic administration of the thrombin inhibitor dabigatran, as well as inhibition of protease-activated receptor-1, prevented trinitrobenzene sulphonic acid-induced colitis in rodent models. Conclusions: Our data demonstrated that increased local thrombin activity, as it occurs in the colon of patients with inflammatory bowel disease, causes mucosal damage and inflammation. Colonic thrombin and protease-activated receptor-1 appear as possible mechanisms involved in mucosal damage and loss of function and therefore represent potential therapeutic targets for treating inflammatory bowel disease

Decline in HIV Prevalence among Young Women in Zambia: National-Level Estimates of Trends Mask Geographical and Socio-Demographic Differences

Background: A decline in HIV incidence has been reported in Zambia and a number of other sub-Saharan countries. The trend of HIV prevalence among young people is a good marker of HIV incidence. In this study, different data sources are used to examine geographical and sub-population group differentials in HIV prevalence trends among men and women aged 15–24 years in Zambia. Design and Methods: We analysed ANC data for women aged 15–24 years from 22 sentinel sites consistently covered in the period 1994–2008, and HIV data for young men and women aged 15–24 years from the ZDHS 2001/2 and 2007. In addition, we systematically reviewed peer-reviewed articles that have reported findings on HIV prevalence and incidence among young people. Findings: Overall trends of the ANC surveillance data indicated a substantial HIV prevalence decline among young women in both urban and rural areas. However, provincial declines differed substantially, i.e. between 10 % and 68 % among urban women, and from stability to 86 % among rural women. Prevalence declines were steeper among those with the highest educational attainments than among the least educated. The ZDHS data indicated a significant reduction in prevalence between the two survey rounds among young women only. Provincial-level ZDHS changes were difficult to assess because the sample sizes were small. ANC-based trend patterns were consistent with those observed in PMTCT-based data (2002

Evaluation of Kenya’s readiness to transition from sentinel surveillance to routine HIV testing for antenatal clinic-based HIV surveillance

BACKGROUND: Sentinel surveillance for HIV among women attending antenatal clinics using unlinked anonymous testing is a cornerstone of HIV surveillance in sub-Saharan Africa. Increased use of routine antenatal HIV testing allows consideration of using these programmatic data rather than sentinel surveillance data for HIV surveillance. METHODS: To gauge Kenya’s readiness to discontinue sentinel surveillance, we evaluated whether recommended World Health Organization standards were fulfilled by conducting data and administrative reviews of antenatal clinics that offered both routine testing and sentinel surveillance in 2010. RESULTS: The proportion of tests that were HIV-positive among women aged 15–49 years was 6.2 % (95 % confidence interval [CI] 4.6–7.7 %] in sentinel surveillance and 6.5 % (95 % CI 5.1–8.0 %) in routine testing. The agreement of HIV test results between sentinel surveillance and routine testing was 98.0 %, but 24.1 % of specimens that tested positive in sentinel surveillance were recorded as negative in routine testing. Data completeness was moderate, with HIV test results recorded for 87.8 % of women who received routine testing. CONCLUSIONS: Additional preparation is required before routine antenatal HIV testing data can supplant sentinel surveillance in Kenya. As the quality of program data has markedly improved since 2010 a repeat evaluation of the use of routine antenatal HIV testing data in lieu of ANC sentinel surveillance is recommended

COVID-19 infection in patients on long-term home parenteral nutrition for chronic intestinal failure

Background and aims: To investigate the incidence and the severity of COVID-19 infection in patients enrolled in the database for home parenteral nutrition (HPN) for chronic intestinal failure (CIF) of the European Society for Clinical Nutrition and Metabolism (ESPEN). Methods: Period of observation: March 1st, 2020 March 1st, 2021. Inclusion criteria: patients included in the database since 2015 and still receiving HPN on March 1st, 2020 as well as new patients included in the database during the period of observation. Data related to the previous 12 months and recorded on March 1st 2021: 1) occurrence of COVID-19 infection since the beginning of the pandemic (yes, no, unknown); 2) infection severity (asymptomatic; mild, no-hospitalization; moderate, hospitalization no-ICU; severe, hospitalization in ICU); 3) vaccinated against COVID-19 (yes, no, unknown); 4) patient outcome on March 1st 2021: still on HPN, weaned off HPN, deceased, lost to follow up. Results: Sixty-eight centres from 23 countries included 4680 patients. Data on COVID-19 were available for 55.1% of patients. The cumulative incidence of infection was 9.6% in the total group and ranged from 0% to 21.9% in the cohorts of individual countries. Infection severity was reported as: asymptomatic 26.7%, mild 32.0%, moderate 36.0%, severe 5.3%. Vaccination status was unknown in 62.0% of patients, non-vaccinated 25.2%, vaccinated 12.8%. Patient outcome was reported as: still on HPN 78.6%, weaned off HPN 10.6%, deceased 9.7%, lost to follow up 1.1%. A higher incidence of infection (p = 0.04), greater severity of infection (p < 0.001) and a lower vaccination percentage (p = 0.01) were observed in deceased patients. In COVID-19 infected patients, deaths due to infection accounted for 42.8% of total deaths. Conclusions: In patients on HPN for CIF, the incidence of COVID-19 infection differed greatly among countries. Although the majority of cases were reported to be asymptomatic or have mild symptoms only, COVID-19 was reported to be fatal in a significant proportion of infected patients. Lack of vaccination was associated with a higher risk of death