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排序方式: 共有234条查询结果,搜索用时 31 毫秒
1.
Rahul S. Loungani Marat Fudim Dave Ranney Ajar Kochar Marc D. Samsky Desiree Bonadonna Akinobu Itoh Hiroo Takayama Koji Takeda Daniel Wojdyla Adam D. DeVore Mani Daneshmand 《Journal of cardiac failure》2021,27(3):327-337
BackgroundVenoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly used as a life-saving therapy for patients with cardiovascular collapse, but identifying patients unlikely to benefit remains a challenge.Methods and ResultsWe created the RESCUE registry, a retrospective, observational registry of adult patients treated with VA-ECMO between January 2007 and June 2017 at 3 high-volume centers (Columbia University, Duke University, and Washington University) to describe short-term patient outcomes. In 723 patients treated with VA-ECMO, the most common indications for deployment were postcardiotomy shock (31%), cardiomyopathy (including acute heart failure) (26%), and myocardial infarction (17%). Patients frequently suffered in-hospital complications, including acute renal dysfunction (45%), major bleeding (41%), and infection (33%). Only 40% of patients (n = 290) survived to discharge, with a minority receiving durable cardiac support (left ventricular assist device [n = 48] or heart transplantation [n = 7]). Multivariable regression analysis identified risk factors for mortality on ECMO as older age (odds ratio [OR], 1.26; 95% confidence interval [CI], 1.12–1.42) and female sex (OR, 1.44; 95% CI, 1.02–2.02) and risk factors for mortality after decannulation as higher body mass index (OR 1.17; 95% CI, 1.01-1.35) and major bleeding while on ECMO support (OR, 1.92; 95% CI, 1.23–2.99).ConclusionsDespite contemporary care at high-volume centers, patients treated with VA-ECMO continue to have significant in-hospital morbidity and mortality. The optimization of outcomes will require refinements in patient selection and improvement of care delivery. 相似文献
2.
本文报道了18例风湿性心脏病伴有左房血栓病人的手术治疗,其中瓣膜置换者5例,二尖瓣直视成形者13例。死亡4例中1例死于脑栓塞。血栓形成和房颤有直接关系。左房血栓术前诊断主要依靠心脏B超,血栓治疗以手术清除为主。为预防术后再发,应纠正房颤及适当应用抗凝血药物。 相似文献
3.
Glycinergic synapses are implicated in the coordination of reflex responses, sensory signal processing and pain sensation. Their activity is pre- and postsynaptically regulated, although mechanisms are poorly understood. Using patch-clamp recording and Ca2 + imaging in hypoglossal motoneurones from rat and mouse brainstem slices, we address here the role of cytoplasmic Ca2 + (Cai ) in glycinergic synapse modulation. Ca2 + influx through voltage-gated or NMDA receptor channels caused powerful transient inhibition of glycinergic IPSCs. This effect was accompanied by an increase in both the failure rate and paired-pulse ratio, as well as a decrease in the frequency of mIPSCs, suggesting a presynaptic mechanism of depression. Inhibition was reduced by the cannabinoid receptor antagonist SR141716A and occluded by the agonist WIN55,212-2, indicating involvement of endocannabinoid retrograde signalling. Conversely, in the presence of SR141716A, glycinergic IPSCs were potentiated postsynaptically by glutamate or NMDA, displaying a Ca2 + -dependent increase in amplitude and decay prolongation. Both presynaptic inhibition and postsynaptic potentiation were completely prevented by strong Cai buffering (20 m m BAPTA). Our findings demonstrate two independent mechanisms by which Ca2 + modulates glycinergic synaptic transmission: (i) presynaptic inhibition of glycine release and (ii) postsynaptic potentiation of GlyR-mediated responses. This dual Ca2 + -induced regulation might be important for feedback control of neurotransmission in a variety of glycinergic networks in mammalian nervous systems. 相似文献
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5.
Aleksandr M. Filimonov Oleg A. Rogozin Denis G. Firsov Yulia O. Kuzminova Semen N. Sergeev Alexander P. Zhilyaev Marat I. Lerner Nikita E. Toropkov Alexey P. Simonov Ivan I. Binkov Ilya V. Okulov Iskander S. Akhatov Stanislav A. Evlashin 《Materials》2021,14(1)
The particle size distribution significantly affects the material properties of the additively manufactured parts. In this work, the influence of bimodal powder containing nano- and micro-scale particles on microstructure and materials properties is studied. Moreover, to study the effect of the protective atmosphere, the test samples were additively manufactured from 316L stainless steel powder in argon and nitrogen. The samples fabricated from the bimodal powder demonstrate a finer subgrain structure, regardless of protective atmospheres and an increase in the Vickers microhardness, which is in accordance with the Hall-Petch relation. The porosity analysis revealed the deterioration in the quality of as-built parts due to the poor powder flowability. The surface roughness of fabricated samples was the same regardless of the powder feedstock materials used and protective atmospheres. The results suggest that the improvement of mechanical properties is achieved by adding a nano-dispersed fraction, which dramatically increases the total surface area, thereby contributing to the nitrogen absorption by the material. 相似文献
6.
Eitan Prisman Marat Slessarev Takafumi Azami Dan Nayot Michael Milosevic 《International journal of radiation biology》2013,89(7):457-462
Purpose: Carbogen has long been under investigation as an adjuvant to radiotherapy of tumors. A major factor confounding its evaluation is its inconsistency in raising blood partial pressure of CO2 (pCO2). We investigated whether a new partial rebreathing method would provide better control of pCO2 than carbogen.Methods and materials: We compared the efficacy of each method in 10 healthy volunteers. Volunteers breathed 1.5, 3 and 5% carbogen in 5-min stages via the usual non-rebreathing circuit. All the volunteers then breathed 100% O2 through a commercial sequential gas delivery (SGD) circuit modified by attaching a reservoir to its exhalation port. Hypercarbia was induced by step reductions in oxygen flow to the SGD circuit. We monitored minute ventilation and end-tidal pCO2 (ETpCO2) as a surrogate for its arterial value.Results: Inhalation of 1.5 and 3% carbogen did not increase ETpCO2 from baseline (40 ± 1.5 mmHg); 5% carbogen increased ETpCO2 to 45 ± 1.6 mmHg (p < 0.001). With the SGD circuit, reducing O2 flow to 4.3 ± 0.7 l/min increased ETpCO2 in all subjects from 41 ± 2.0 mmHg (baseline) to 46 ± 2.1 mmHg (p < 0.001). Voluntary hyperventilation reduced ETpCO2 with 5% carbogen but not with SGD (p = 0.379).Conclusions: We confirm previous observations that carbogen inhalation does not result in a predictable rise in ETpCO2 and suggest that a precise and stable target ETpCO2 can instead be induced by simply controlling O2 flow into a modified SGD circuit. We hoped that the reliable control of pCO2 will enable studies that address first, the efficacy of raising ETpCO2 on specific tumor blood flow, and eventually, its benefit as an adjuvant to radiotherapy. 相似文献
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8.
Aetiology,timing and clinical predictors of early vs. late readmission following index hospitalization for acute heart failure: insights from ASCEND‐HF 下载免费PDF全文
Marat Fudim Christopher M. O'Connor Allison Dunning Andrew P. Ambrosy Paul W. Armstrong Adrian Coles Justin A. Ezekowitz Stephen J. Greene Marco Metra Randall C. Starling Adriaan A. Voors Adrian F. Hernandez G. Michael Felker Robert J. Mentz 《European journal of heart failure》2018,20(2):304-314
Aims
Patients hospitalized for heart failure (HF) are at high risk for 30‐day readmission. This study sought to examine the timings and causes of readmission within 30 days of an HF hospitalization.Methods and results
Timing and cause of readmission in the ASCEND‐HF (Acute Study of Clinical Effectiveness of Nesiritide and Decompensated Heart Failure) trial were assessed. Early and late readmissions were defined as admissions occurring within 0–7 days and 8–30 days post‐discharge, respectively. Patients who died in hospital or remained hospitalized at day 30 post‐randomization were excluded. Patients were compared by timing and cause of readmission. Logistic and Cox proportional hazards regression analyses were used to identify independent risk factors for early vs. late readmission and associations with 180‐day outcomes. Of the 6584 patients (92%) in the ASCEND‐HF population included in this analysis, 751 patients (11%) were readmitted within 30 days for any cause. Overall, 54% of readmissions were for non‐HF causes. The median time to rehospitalization was 11 days (interquartile range: 6–18 days) and 33% of rehospitalizations occurred by day 7. Rehospitalization within 30 days was independently associated with increased risk for 180‐day all‐cause death [hazard ratio (HR) 2.38, 95% confidence interval (CI) 1.93–2.94; P < 0.001]. Risk for 180‐day all‐cause death did not differ according to early vs. late readmission (HR 0.99, 95% CI 0.67–1.45; P = 0.94).Conclusions
In this hospitalized HF trial population, a significant majority of 30‐day readmissions were for non‐HF causes and one‐third of readmissions occurred in the first 7 days. Early and late readmissions within the 30‐day timeframe were associated with similarly increased risk for death. Continued efforts to optimize multidisciplinary transitional care are warranted to improve rates of early readmission.9.
Roy Mashiach Vadym Mezhybovsky Avinoam Nevler Mordechai Gutman Amitai Ziv Marat Khaikin 《Surgical endoscopy》2014,28(12):3489-3493
Study objective
The objective of this study was to evaluate and compare the impact of three-dimensional (3D) imaging system on the performance of basic laparoscopic tasks in a test model by novice and experienced surgeons.Design
Three tasks were performed in a test model by 30 surgeons, 15 experienced surgeons, and 15 with minimal laparoscopic experience. The tasks were performed using 2D and 3D vision systems.Design classification
Canadian Task Force II-1.Subjects
Fifteen experienced laparoscopic surgeons and fifteen novices with minimal laparoscopic experience.Measurements
Performance times were recorded using both two-dimensional and 3D imaging system for each task.Main results
Performance time for all skills was significantly (P < 0.02) shorter when using 3D imaging system. Performance times were reduced by 18–31 % using 3D imaging for all participants. Experienced surgeons performed the tasks faster and showed similar improvement while using 3D imaging system.Conclusion
3D vision systems allow for significant improvement in performance times of basic laparoscopic tasks in a test model for both inexperienced and advanced laparoscopic surgeons. Experienced surgeons benefit as much as novices from 3D imaging system. This benefit should be weighed against the disadvantages of the 3D vision systems, mainly cost, decreased light, eye strain, headaches, and shorter focal lengths. 相似文献10.
Marat A. Mukhamedyarov Julia O. Kochunova Bulat A. Haidarov András Palotás 《Brain research bulletin》2010,81(6):613-616
Calcium/calmodulin-dependent protein-kinase II (CaMKII) is a ubiquitous intracellular enzyme, which is implicated in learning and memory mechanisms in the central nervous system, however its contribution to peripheral cholinergic neurotransmission is not well characterized. This study evaluated the impact of CaMKII on the function of frog neuromuscular synapse using electrophysiological recordings. Application of the selective CaMKII inhibitor KN-93 (5 μM) did not significantly alter the parameters of evoked and spontaneous quantal acetylcholine release under low-frequency stimulation (0.03 Hz). KN-93, on the other hand, produced pronounced changes in short-term synaptic plasticity: particularly, KN-93 inhibits the second component of paired-pulse facilitation (interpulse intervals of 100 ms and longer) and strengthens the depression of synaptic transmission under high-frequency stimulation (50 Hz). These results imply that CaMKII plays an important role in presynaptic functions at the frog neuromuscular junction, and potentiates quantal acetylcholine release under high-frequency activity. 相似文献