21 research outputs found
Исследование деформации речных русел как фактора аварийности на нефтегазотранспортных системах Западной Сибири на примере реки Кия
По данным гидрометрических наблюдений за период с 1955 по 1974 год,полученных на государственной сети наблюдений Российской Федеральной службы по гидрометеорологии и мониторингу окружающей среды, проведена оценка и долгосрочный прогноз русловых деформаций реки Кия при отсутствии данных наблюдений. Методика основана на определении параметров потока, при которых наблюдаются наибольшие деформации русла реки. Evaluation and long-term forecast of the river channel deformation Kiya is carried out in the absence of observations by standard data of hydrometric observations for the period from 1955 to 1974. Data collected at the state observing network of the Russian Federal Service for Hydrometeorology and Environmental Monitoring (Roshydromet). The technique is based on determination of flow parameters, at which the maximum river bed deformations are observed
The Uracil DNA Glycosylase UdgB of Mycobacterium smegmatis Protects the Organism from the Mutagenic Effects of Cytosine and Adenine Deamination▿
Spontaneous hydrolytic deamination of DNA bases represents a considerable mutagenic threat to all organisms, particularly those living in extreme habitats. Cytosine is readily deaminated to uracil, which base pairs with adenine during replication, and most organisms encode at least one uracil DNA glycosylase (UDG) that removes this aberrant base from DNA with high efficiency. Adenine deaminates to hypoxanthine approximately 10-fold less efficiently, and its removal from DNA in vivo has to date been reported to be mediated solely by alkyladenine DNA glycosylase. We previously showed that UdgB from Pyrobaculum aerophilum, a hyperthermophilic crenarchaeon, can excise hypoxanthine from oligonucleotide substrates, but as this organism is not amenable to genetic manipulation, we were unable to ascertain that the enzyme also has this role in vivo. In the present study, we show that UdgB from Mycobacterium smegmatis protects this organism against mutagenesis associated with deamination of both cytosine and adenine. Together with Ung-type uracil glycosylase, M. smegmatis UdgB also helps attenuate the cytotoxicity of the antimicrobial agent 5-fluorouracil
Early Postoperative Neurologic Events Are Associated With Worse Outcome and Fatal Midterm Survival After Adult Heart Transplantation
Background Neurologic events during primary stay in heart transplant (HTx) recipients may be associated with reduced outcome and survival, which we aim to explore with the current study. Methods and Results We screened and included all patients undergoing HTx in our center between September 2010 and December 2022 (n=268) and checked for the occurrence of neurologic events within their index stay. Neurologic events were defined as ischemic stroke, hemorrhage, hypoxic ischemic injury, or acute symptomatic neurologic dysfunction without central nervous system injury. The cohort was then divided into recipients with (n=33) and without (n=235) neurologic events after HTx. Using a multivariable Cox regression model, the association of neurologic events after HTx and survival was assessed. Recipients with neurologic events displayed a longer intensive care unit stay (30 versus 16 days; P=0.009), longer mechanical ventilation (192 versus 48 hours; P<0.001), and higher need for blood transfusion, and need for hemodialysis after HTx was substantially higher (81% versus 55%; P=0.01). Resternotomy (36% versus 26%; P=0.05) and mechanical life support (extracorporeal life support) after HTx (46% versus 24%; P=0.02) were also significantly higher in patients with neurologic events. Covariable‐adjusted multivariable Cox regression analysis revealed a significant independent association of neurologic events and increased 30‐day (hazard ratio [HR], 2.5 [95% CI, 1.0–6.0]; P=0.049), 1‐year (HR, 2.2 [95% CI, 1.1–4.3]; P=0.019), and overall (HR, 2.5 [95% CI, 1.5–4.2]; P<0.001) mortality after HTx and reduced Kaplan‐Meier survival up to 5 years after HTx (P<0.001). Conclusions Neurologic events after HTx were strongly and independently associated with worse postoperative outcome and reduced survival up to 5 years after HTx