• 1 Climate drives vein anatomy in Proteaceae. 复制标题 收藏 收藏

    【气候推动了Proteaceae的静脉解剖。】 复制标题 收藏 收藏
    DOI:10.3732/ajb.1200471 复制DOI
    作者列表:Jordan GJ,Brodribb TJ,Blackman CJ,Weston PH
    BACKGROUND & AIMS: PREMISE OF STUDY:The mechanisms by which plants tolerate water deficit are only just becoming clear. One key factor in drought tolerance is the ability to maintain the capacity to conduct water through the leaves in conditions of water stress. Recent work has shown that a simple feature of the leaf xylem cells, the cube of the thickness of cell walls divided by the lumen width (t/b)(3), is strongly correlated with this ability. METHODS:Using ecologically, phylogenetically, and anatomically diverse members of Proteaceae, we tested the relationships between (t/b)(3) and climate, leaf mass per unit area, leaf area, and vein density. To test relationships at high phylogenetic levels (mostly genus), we used phylogenetic and nonphylogenetic single and multiple regressions based on data from 50 species. We also used 14 within-genus species pairs to test for relationships at lower phylogenetic levels. KEY RESULTS:All analyses revealed that climate, especially mean annual precipitation, was the best predictor of (t/b)(3). The variation in (t/b)(3) was driven by variation in both lumen diameter and wall thickness, implying active control of these dimensions. Total vein density was weakly related to (t/b)(3) but unrelated to either leaf area or climate. CONCLUSIONS:We conclude that xylem reinforcement is a fundamental adaptation for water stress tolerance and, among evergreen woody plants, drives a strong association between rainfall and xylem anatomy. The strong association between (t/b)(3) and climate cannot be explained by autocorrelation with other aspects of leaf form and anatomy that vary along precipitation gradients.
    背景与目标:
  • 【11月芽孢杆菌,一种新的轻度嗜盐细菌,从深海沉积物环境中分离出来。】 复制标题 收藏 收藏
    DOI:10.1007/s10482-013-9995-0 复制DOI
    作者列表:Liu YJ,Long LJ,Huang XF,You ZQ,Wang FZ,Li J,Kim CJ,Tian XP,Zhang S
    BACKGROUND & AIMS: :A strictly aerobic, Gram-stain positive, slightly halophilic strain, designated SCSIO 04524(T), was isolated from a deep sea sediment sample collected from the northern South China Sea at a depth of 3415 m. The isolate slightly embedded into the medium after 72 h incubation at 30 °C. Growth was found to occur on media with 0-10 % NaCl but extremely weak growth occurred without supplying NaCl. The predominant menaquinone was determined to be MK-7. The major cellular fatty acid identified was iso-C15:0. The diagnostic polar lipids were determined to be diphosphatidylglycerol, phosphatidyl methylethanolamine, phosphatidylethanolamine and phosphatidylglycerol. The genomic DNA G+C content was determined to be 38 mol%. 16S rRNA gene sequences analysis showed that this strain had the highest similarities with Bacillus carboniphilus JCM 9731(T) (94.7 %) and Bacillus endophyticus 2DT(T) (94.3 %). Phylogenetic analysis revealed that strain SCSIO 04524(T) formed a distinct lineage with Bacillus chungangensis CAU 348(T) and B. carboniphilus JCM 9731(T). Physiological characteristics including utilization of sole nitrogen and carbon sources, and chemotaxonomic properties of cellular fatty acids and polar lipids could readily distinguish strain SCSIO 04524(T) from its most closely related species. Based on this polyphasic taxonomic data, a new species, Bacillus oceani sp. nov., is proposed, with the type strain SCSIO 04524(T) (=DSM 26213(T) = KCTC 33077(T)).
    背景与目标: : 从从南海北部收集的深度为3415 m的深海沉积物样品中分离出严格需氧,革兰氏染色阳性,轻度嗜盐菌株,命名为SCSIO 04524(T)。在30 °C孵育72小时后,该分离物略微嵌入培养基中。发现在具有0-10% NaCl的培养基上发生生长,但是在不提供NaCl的情况下发生极弱的生长。主要的menaquinone被确定为MK-7。所鉴定的主要细胞脂肪酸为iso-C15:0。诊断极性脂质被确定为二磷脂酰甘油,磷脂酰甲基乙醇胺,磷脂酰乙醇胺和磷脂酰甘油。确定基因组DNA G C含量为38 mol %。16S rRNA基因序列分析表明,该菌株与碳酸芽孢杆菌JCM 9731(T) (94.7%) 和内生芽孢杆菌2DT(T) (94.3%) 具有最高的相似性。系统发育分析表明,菌株SCSIO 04524(T) 与重庆芽孢杆菌CAU 348(T) 和B. carboniphilus JCM 9731(T) 形成了独特的谱系。生理特性,包括唯一的氮和碳源的利用,以及细胞脂肪酸和极性脂质的化学分类特性,可以很容易地将SCSIO 04524(T) 菌株与其最密切相关的物种区分开。基于这一多相分类学数据,提出了一种新的物种,11月芽孢杆菌,其类型为SCSIO 04524(T) (= DSM 26213(T) = KCTC 33077(T))。
  • 【皮质深层的gaba能神经元和锥体神经元直接接受并不同地整合call骨输入。】 复制标题 收藏 收藏
    DOI:10.1093/cercor/bhl035 复制DOI
    作者列表:Karayannis T,Huerta-Ocampo I,Capogna M
    BACKGROUND & AIMS: :We studied the involvement of deep cortical layer neurons in processing callosal information in the rat. We observed with electron microscopy that both parvalbumin (PV)-labeled profiles and unlabeled dendritic spines of deep cortical layer neurons receive synapses from the contralateral hemisphere. Stimulation of callosal fibers elicited monosynaptic excitatory postsynaptic currents in both layer VI pyramidal neurons and gamma-aminobutyric acidergic (GABAergic) interneurons immunopositive for the vesicular GABA transporter and PV. Pyramidal cells had intrinsic electrophysiological properties and synaptic responses with slow kinetics and a robust N-metyhl-D-aspartate (NMDA) component. In contrast, GABAergic interneurons had intrinsic membrane properties and synaptic responses with faster kinetics and a less pronounced NMDA component. Consistent with these results, the temporal integration of callosal input was effective over a significantly longer time window in pyramidal neurons compared with GABAergic interneurons. Interestingly, callosal stimulation did not evoke feedforward inhibition in all GABAergic interneurons and in the majority of pyramidal neurons tested. Furthermore, retrogradely labeled layer VI pyramidal neurons of the contralateral cortex responded monosynaptically to callosal stimulation, suggesting interconnectivity between callosally projecting neurons. The data show that pyramidal neurons and GABAergic interneurons of deep cortical layers receive interhemispheric information directly and have properties supporting their distinct roles.
    背景与目标: : 我们研究了深皮质层神经元在处理大鼠call骨信息中的参与。我们用电子显微镜观察到,浅白蛋白 (PV) 标记的轮廓和深皮质层神经元的未标记的树突棘均从对侧半球接收突触。Call骨纤维的刺激在VI层锥体神经元和 γ-氨基丁酸 (GABA能) 中间神经元中均引起单突触兴奋性突触后电流,对囊泡GABA转运蛋白和PV免疫呈阳性。锥体细胞具有内在的电生理特性和突触反应,动力学缓慢,并且具有强大的N-metyhl-D-天冬氨酸 (NMDA) 成分。相反,gaba能中间神经元具有内在的膜特性和突触反应,其动力学更快,NMDA成分不那么明显。与这些结果一致,与gaba能中间神经元相比,在锥体神经元中,call骨输入的时间整合在明显更长的时间窗口内有效。有趣的是,在所有gaba能中间神经元和大多数测试的锥体神经元中,call刺激并未引起前馈抑制。此外,对侧皮层的逆行标记的第VI层锥体神经元对call骨刺激单突触反应,表明call骨投射神经元之间的相互连接。数据表明,皮层深层的锥体神经元和gaba能中间神经元直接接收半球间信息,并具有支持其独特作用的特性。
  • 【视网膜静脉阻塞的15年累积发病率: 海狸坝眼研究。】 复制标题 收藏 收藏
    DOI:10.1001/archopht.126.4.513 复制DOI
    作者列表:Klein R,Moss SE,Meuer SM,Klein BE
    BACKGROUND & AIMS: OBJECTIVES:To describe the 15-year incidence of retinal vein occlusion (central retinal vein occlusion and branch retinal vein occlusion) and associated risk factors. METHODS:A population-based study where branch retinal vein occlusion and central retinal vein occlusion were detected at baseline (n = 4068, 1988-1990) and three 5-year follow-up examinations by grading 30 degrees color fundus photographs. RESULTS:The 15-year cumulative incidences of branch retinal vein occlusion and central retinal vein occlusion were 1.8% and 0.5%, respectively. Using a generalized estimating equation model, incident retinal vein occlusion was related to baseline age (odds ratio [OR] per 10 years, 1.70; 95% confidence interval [CI], 1.36-2.12), history of barbiturate use (OR, 5.30; 95% CI, 2.28-12.31), focal retinal arteriolar narrowing (OR, 2.45; 95% CI, 1.29-4.66), glaucoma (OR, 3.17; 95% CI, 1.50-6.69), serum ionized calcium level (OR per 0.4 mg/dL, 0.43; 95% CI, 0.23-0.79), serum phosphorus level (OR per 0.3 mg/dL, 1.15; 95% CI, 1.01-1.30), and serum creatinine level (OR for > or = 1.4 vs < 1.4 mg/dL, 1.61; 95% CI, 1.00-2.59). Migraine headache history was associated with branch retinal vein occlusion (OR, 1.99; 95% CI, 1.08-3.67). Diabetes history was associated with central retinal vein occlusion (OR, 6.35; 95% CI, 1.90-21.27). CONCLUSIONS:Incident retinal vein occlusion is not infrequent in the population, especially after age 65 years. The relationships of barbiturate use, serum creatinine level, serum ionized calcium level, and serum phosphorus level with incident retinal vein occlusion require further assessment in other large population-based studies.
    背景与目标:
  • 【眼上静脉的外科插管治疗先前栓塞的海绵窦硬脑膜动静脉瘘: 系列研究和血管造影随访。】 复制标题 收藏 收藏
    DOI:10.3109/02688697.2012.722238 复制DOI
    作者列表:Luo B,Zhang X,Duan CZ,He XY,Li XF,Karuna T,Gu DQ,Long XA,Li TL,Zhang SZ,Ke YQ,Jiang XD
    BACKGROUND & AIMS: OBJECTIVE:The purpose of this study was to evaluate the safety and efficacy of transorbital puncture for the retreatment of previously embolized cavernous sinus dural arteriovenous fistulas (DAVFs) via a superior ophthalmic vein (SOV) approach. MATERIALS AND METHODS:During a 12-year period, 9 consecutive patients with previously embolized cavernous sinus DAVFs underwent retreatment via the transorbital SOV approach. RESULTS:All of the nine cases of previously embolized cavernous sinus DAVFs were successfully embolized. Clinical follow-ups were conducted in all nine cases at the duration of 17-141 months (61.22 ± 39.13 months). No recanalization occurred during the follow-up period. A subtle ptosis appeared in two patients and disappeared in one of the two cases after a 4-year follow-up. One patient suffered from paroxysmal positional vertigo and bruit for nearly 2 years after the treatment, but the follow-up angiography demonstrated no recurrence. One patient had persistent visual impairment caused by the initial venous stasis retinopathy. One patient with a history of a procedure-related transient decrease in visual acuity had it return to the normal level. The remaining four cases had clear improvement in the ocular symptoms and became completely asymptomatic during the follow-up period. No patient worsened or developed new symptoms. CONCLUSION:The approach of surgical cannulation of the SOV for the retreatment of previously embolized cavernous sinus DAVFs was proved feasible and efficient, especially when the transarterial and transfemoral venous approaches were inaccessible. However, if the SOV is not dilated enough or is located deeply in the orbit, transorbital venous puncture access may not be possible.
    背景与目标:
  • 【基于深度学习方法的赖氨酸琥珀酰化位点表征和鉴定。】 复制标题 收藏 收藏
    DOI:10.1038/s41598-019-52552-4 复制DOI
    作者列表:Huang KY,Hsu JB,Lee TY
    BACKGROUND & AIMS: :Succinylation is a type of protein post-translational modification (PTM), which can play important roles in a variety of cellular processes. Due to an increasing number of site-specific succinylated peptides obtained from high-throughput mass spectrometry (MS), various tools have been developed for computationally identifying succinylated sites on proteins. However, most of these tools predict succinylation sites based on traditional machine learning methods. Hence, this work aimed to carry out the succinylation site prediction based on a deep learning model. The abundance of MS-verified succinylated peptides enabled the investigation of substrate site specificity of succinylation sites through sequence-based attributes, such as position-specific amino acid composition, the composition of k-spaced amino acid pairs (CKSAAP), and position-specific scoring matrix (PSSM). Additionally, the maximal dependence decomposition (MDD) was adopted to detect the substrate signatures of lysine succinylation sites by dividing all succinylated sequences into several groups with conserved substrate motifs. According to the results of ten-fold cross-validation, the deep learning model trained using PSSM and informative CKSAAP attributes can reach the best predictive performance and also perform better than traditional machine-learning methods. Moreover, an independent testing dataset that truly did not exist in the training dataset was used to compare the proposed method with six existing prediction tools. The testing dataset comprised of 218 positive and 2621 negative instances, and the proposed model could yield a promising performance with 84.40% sensitivity, 86.99% specificity, 86.79% accuracy, and an MCC value of 0.489. Finally, the proposed method has been implemented as a web-based prediction tool (CNN-SuccSite), which is now freely accessible at http://csb.cse.yzu.edu.tw/CNN-SuccSite/ .
    背景与目标: : 琥珀酰化是蛋白质翻译后修饰 (PTM) 的一种,可以在多种细胞过程中发挥重要作用。由于从高通量质谱 (MS) 获得的位点特异性琥珀酰化肽的数量不断增加,因此已开发出各种工具来计算识别蛋白质上的琥珀酰化位点。但是,大多数这些工具都基于传统的机器学习方法来预测琥珀酰化位点。因此,这项工作旨在基于深度学习模型进行琥珀酰化位点预测。MS验证的琥珀酰化肽的丰度使得能够通过基于序列的属性 (例如位置特异性氨基酸组成,k间隔氨基酸对 (CKSAAP) 的组成和位置特异性评分矩阵 (PSSM)) 研究琥珀酰化位点的底物位点特异性。此外,通过将所有琥珀酰化序列分为几个具有保守的底物基序的组,采用最大依赖性分解 (MDD) 来检测赖氨酸琥珀酰化位点的底物特征。根据十倍交叉验证的结果,使用PSSM和信息性CKSAAP属性训练的深度学习模型可以达到最佳的预测性能,并且性能也优于传统的机器学习方法。此外,使用训练数据集中真正不存在的独立测试数据集将所提出的方法与六种现有的预测工具进行比较。测试数据集由218阳性和2621阴性实例组成,所提出的模型可以产生具有84.40% 灵敏度、86.99% 特异性、86.79% 准确性和0.489 MCC值的有希望的性能。最后,所提出的方法已实现为基于web的预测工具 (cnn-succsite),现在可以在http://csb.cse.yzu.edu.tw/cnn-succsite/上自由访问。
  • 【沙特阿拉伯三级医院深静脉血栓的医院与家庭治疗: 我们准备好了吗?】 复制标题 收藏 收藏
    DOI:10.1016/j.jsps.2012.05.008 复制DOI
    作者列表:Algahtani F,Aseri ZA,Aldiab A,Aleem A
    BACKGROUND & AIMS: AIM/BACKGROUND:Treatment of DVT with LMWHs has been shown recently to be as effective as UFH with suggested lower costs. This study was conducted to determine and compare the cost of in-patient hospital treatment versus outpatient hospital treatment of patients with DVT. METHOD:All adult patients with acute proximal DVT referred to the Emergency Department of King Khalid University Hospital, Riyadh, Saudi Arabia between August 2009 and August 2010 were invited to the study. An economic analysis was performed to compare the cost impact of outpatients versus hospital treatment. RESULTS:Sixty-one patients were included in the study, 31 were followed in the outpatient setting and 30 as the control group (inpatients). There were no significant differences in the outcome between the outpatient and inpatient group; three patients (9.7%) in the outpatient group and four patients (13.3%) in the inpatient group had recurrent DVT. Mean nursing cost was $55 for the outpatient group and $215 for the inpatient group, mean laboratory monitoring cost was $638 for outpatient group and $1511 for the inpatient group. Hospital stay and doctor's fees amounted to a mean of $1000 for outpatient treatment and $2387 for inpatient treatment, p < 0.0001. The mean outpatient cost was significantly lower than the inpatient cost ($1750 vs. $4338, p < 0.0001). CONCLUSION:Outpatient treatment of patients with DVT using LMWHs is cost-effective with no significant differences in the outcome of patients. OPD treatment of DVT is feasible in Saudi Arabia provided there is enough logistic support from thrombosis clinics and those involved in DVT care.
    背景与目标:
  • 【肺静脉解剖对房颤导管消融预后的影响。】 复制标题 收藏 收藏
    DOI:10.3390/medicina55110727 复制DOI
    作者列表:Istratoaie S,Roșu R,Cismaru G,Vesa ȘC,Puiu M,Zdrenghea D,Pop D,Buzoianu AD
    BACKGROUND & AIMS: :Background and Objectives: Prior studies have identified a number of predictors for Atrial fibrillation (AF) ablation success, including comorbidities, the type of AF, and left atrial (LA) size. Ectopic foci in the initiation of paroxysmal AF are frequently found in pulmonary veins. Our aim was to assess how pulmonary vein anatomy influences the recurrence of atrial fibrillation after radiofrequency catheter ablation. Materials and Methods: Eighty patients diagnosed with paroxysmal or persistent AF underwent radiofrequency catheter ablation (RFCA) between November 2016 and December 2017. All of these patients underwent computed tomography before AF ablation. PV anatomy was classified according to the presence of common PVs or accessory PVs. Several clinical and imagistic parameters were recorded. After hospital discharge, all patients were scheduled for check-up in an outpatient clinic at 3, 6, 9, and 12 months after RFCA to detect AF recurrence. Results: A total of 80 consecutive patients, aged 53.8 ± 9.6 years, 54 (67.5%) men and 26 (32.5%) women were enrolled. The majority of patients had paroxysmal AF 53 (66.3%). Regular PV anatomy (2 left PVs, 2 right PVs) was identified in 59 patients (73.7%), a left common trunk (LCT) was detected in 15 patients (18.7%), an accessory right middle pulmonary vein (RMPV) was found in 5 patients (6.25%) and one patient presented both an LCT and an RMPV. The median follow-up duration was 14 (12; 15) months. Sinus rhythm was maintained in 50 (62.5%) patients. Age, gender, antiarrhythmic drugs, and the presence of cardiac comorbidities were not predictive of AF recurrence. The diagnosis of persistent AF before RFCA was more closely associated with an increase in recurrent AF after RFCA than after paroxysmal AF (p = 0.01). Longer procedure times (>265 minutes) were associated with AF recurrence (p = 0.04). Patients with an LA volume index of over 48.5 (mL/m2) were more likely to present AF recurrence (p = 0.006). Multivariate analysis of recurrence risk showed that only the larger LA volume index and variant PV anatomy were independently associated with AF recurrence. Conclusion: The study demonstrated that an increased volume of the left atrium was the most important predictive factor for the risk of AF recurrence after catheter ablation. Variant anatomy of PV was the only other independent predictive factor associated with a higher rate of AF recurrence.
    背景与目标: 背景和目的: 先前的研究已经确定了心房颤动 (AF) 消融成功的许多预测因素,包括合并症,AF的类型和左心房 (LA) 大小。在肺静脉中经常发现阵发性房颤的异位灶。我们的目的是评估肺静脉解剖结构如何影响射频导管消融后房颤的复发。材料和方法: 80例确诊为阵发性或持续性房颤的患者在2016年11月和2017年12月之间进行了射频导管消融 (RFCA)。所有这些患者在AF消融前均接受了计算机断层扫描。根据常见PVs或辅助PVs的存在对PV解剖进行分类。记录了几个临床和影像学参数。出院后,所有患者都计划在RFCA后3、6、9和12个月在门诊进行检查,以检测AF复发。结果: 共纳入80例连续患者,年龄53.8 ± 9.6岁,54 (67.5%) 名男性和26 (32.5%) 名女性。大多数患者有阵发性AF 53 (66.3%)。在59例患者 (73.7% 例) 中发现了常规的PV解剖 (2例左PVs,2例右PVs),在15例患者 (18.7% 例) 中发现了左主干 (LCT),在5例患者 (6.25% 例) 中发现了右中肺静脉 (RMPV),一名患者同时出现了LCT和RMPV。中位随访时间为14 (12; 15) 个月。50 (62.5%) 例患者维持窦性心律。年龄,性别,抗心律失常药物和心脏合并症的存在不能预测AF复发。与阵发性房颤相比,RFCA前持续性房颤的诊断与RFCA后复发性房颤的增加更密切相关 (p = 0.01)。较长的手术时间 (>265分钟) 与房颤复发相关 (p = 0.04)。LA体积指数超过48.5 (mL/m2) 的患者更有可能出现AF复发 (p = 0.006)。复发风险的多因素分析表明,只有较大的LA体积指数和变异的PV解剖结构与AF复发独立相关。结论: 研究表明,左心房体积增加是导管消融后房颤复发风险的最重要预测因素。PV的变异解剖结构是与更高的AF复发率相关的唯一其他独立预测因素。
  • 【伴有或不伴有心脏骤停的STEMI患者血栓形成和出血的平衡: 一项观察性研究。】 复制标题 收藏 收藏
    DOI:10.1016/j.resuscitation.2019.10.022 复制DOI
    作者列表:Picard F,Llitjos JF,Diefenbronn M,Laghlam D,Seret G,Sokoloff A,Cariou A,Dumas F,Varenne O
    BACKGROUND & AIMS: BACKGROUND:Data is scarce on hemorrhagic and thrombotic complications in patients with ST-elevation myocardial infarction (STEMI) associated with out-of-hospital cardiac arrest (OHCA). METHODS:This is a monocentric, retrospective study conducted from January 2012 to December 2017 in a tertiary university hospital, which serves as a cardiac arrest center for a large urban area. Over the study period, all consecutive patients who were treated with stent implantation for STEMI with or without OHCA were included. Baseline characteristics, treatments, hemorrhagic and thrombotic events were compared between STEMI patients with and without OHCA. Univariate and multivariate analysis were performed in order to identify predictors of 30-day mortality, occurrence of major bleeding (MB), and early stent thrombosis (ST). RESULTS:A total of 549 patients treated for STEMI without OHCA and 146 patients for STEMI with OHCA were included. The incidence of definite ST and MB after coronary angioplasty was significantly higher in patients with OHCA (2.6% vs. 7.5%, p = 0.004 and 3.3% vs. 19.2%, p < 0.001, respectively). Independent predictors of MB in OHCA patients were anticoagulation therapy (HR = 3.11, 95%CI [1.22-7.98], p = 0.02) and the use of glycoprotein IIb/IIIa inhibitors (HR = 4.16, 95%CI [1.61-10.79], p = 0.003). Independent predictors of mortality in OHCA patients were age (HR = 1.05, 95%CI [1.02-1.09], p = 0.004) and ST (HR = 5.62, 95%CI [1.61-19.65], p = 0.007, with a protective effect of new anti-P2Y12 treatments (HR = 0.20, 95%CI [0.08-0.46], p < 0.001). CONCLUSION:Patients treated for STEMI associated with OHCA are at higher-risk of ST and MB than those who did not experience cardiac arrest. In this subset of patients, prospective studies are needed to better evaluate the balance of thrombosis and hemorrhage.
    背景与目标:
  • 【核心标记技术 (CLT): 一种用于深根研究的向内生长核心方法和示踪技术的新组合。】 复制标题 收藏 收藏
    DOI:10.1186/s13007-020-00622-4 复制DOI
    作者列表:Han E,Dresbøll DB,Thorup-Kristensen K
    BACKGROUND & AIMS: Background:Ingrowth-core method is a useful tool to determine fine root growth of standing crops by inserting root-free soil in mesh-bags for certain period of time. However, the root density observed by the method does not directly explain the nutrient uptake potential of crop plants as it varies over soil depth and incubation time. We have inserted an access-tube up to 4.2 m of soil depth with openings directly under crop plants, through which ingrowth-cores containing labelled soil with nutrient tracers were installed, called core-labelling technique (CLT). The main advantage of CLT would be its capacity to determine both root density and root activity from the same crop plants in deep soil layers. We tested the validity of the new method using a model crop species, alfalfa (Medicago sativa) against three depth-levels (1.0, 2.5 and 4.2 m), three sampling spots with varying distance (0-0.36, 0.36-0.72 and > 5 m from core-labelled spot), two sampling times (week 4 and 8), and two plant parts (young and old leaves) under two field experiments (spring and autumn). Results:Using CLT, we were able to observe both deep root growth and root activity up to 4.2 m of soil depth. Tracer concentrations revealed that there was no sign of tracer-leakage to adjacent areas which is considered to be advantageous over the generic tracer-injection. Root activity increased with longer incubation period and tracer concentrations were higher in younger leaves only for anionic tracers. Conclusions:Our results indicate that CLT can lead to a comprehensive deep root study aiming at measuring both deep root growth and root activity from the same plants. Once produced and installed, the access-tubes and ingrowth-cores can be used for a long-term period, which reduces the workload and cost for the research. Therefore, CLT has a wide range of potential applications to the research involving roots in deep soil layers, which requires further confirmation by future experiments.
    背景与目标:
  • 【在大鼠模型中通过术前输注甘草酸苷预防静脉血栓形成。】 复制标题 收藏 收藏
    DOI:10.1007/s00776-008-1259-x 复制DOI
    作者列表:Nakata N,Kira Y,Yabunaka Y,Takaoka K
    BACKGROUND & AIMS: BACKGROUND:Glycyrrhizin is an agent with the capacity to bind to selectin molecules expressed on vascular endothelial cells and potentially prevent the adherence of neutrophils to the vascular endothelial surface. It has been found to prevent intravenous thrombus formation. METHODS:Venous thrombosis was induced in male rats by ligation of the inferior vena cava (IVC) for 6 h. Before the ligation, the study rats were given intravenous injections of glycyrrhizin through the IVC. After 6 h of venous ligation, the rats were sacrificed and the IVC segments were harvested. Thrombus within the IVC was collected to measure the wet weight. Gene expression of P-, L-, and E-selectin was detected by reverse transcriptase polymerase chain reaction using extracts of mRNA from the IVC vein wall. As baseline controls, IVC samples without ligation were harvested immediately after laparotomy. Neutrophil adhesion to the luminal surface of IVC was assessed on histological sections stained with hematoxylin and eosin. Blood samples were collected through the IVC proximal to the ligation after 6 h to estimate activated partial thromboplastin time (APTT) and prothrombin time (PT). To investigate the effect of glycyrrhizin on binding capacity of P-selectin to human neutrophils, real-time biospecific interaction analysis was performed with the Biacore 2000 system. RESULTS:The mean weight of thrombus in the glycyrrhizintreated group was 12.9 +/- 11.1 mg, which is significantly lower than that of the saline-treated control group (21.3 +/- 12.5 mg). The expression level of P-and L-selectin mRNA in both saline-and glycyrrhizin-treated groups was significantly higher than that of the baseline control. Histological studies of cross sections of IVC showed significantly fewer neutrophils adhering to the luminal surface with glycyrrhizin treatment than in the saline-treated controls. There was no significant difference in the values of coagulation parameters with or without glycyrrhizin treatment. In vitro analysis showed that glycyrrhizin caused a dose-dependent reduction of neutrophils binding to immobilized recombinant P-selectin. CONCLUSIONS:Preoperative treatment with glycyrrhizin is potentially useful for preventing venous thrombosis by suppressing the adherence of neutrophils to the venous endothelium during the initial phase of thrombus formation without reducing coagulation capacity and the subsequent risk for increased bleeding.
    背景与目标:
  • 【在体外记录的深背角神经元对年轻大鼠脊髓的直接和正畸刺激的反应。】 复制标题 收藏 收藏
    DOI:10.1016/0306-4522(88)90233-3 复制DOI
    作者列表:King AE,Thompson SW,Urban L,Woolf CJ
    BACKGROUND & AIMS: :The electrophysiological properties of 87 neurons in the deep dorsal horn (laminae III-VI) of the rat spinal cord have been investigated in vitro. Two preparations have been used; the transverse spinal cord slice preparation from the third or fourth lumbar segments of 14-16-day-old rats (71 cells) and a hemisected lumbar spinal cord preparation from 10-12-day-old rats (16 cells). The input impedances (range 11-128 M omega), membrane potentials (-67 +/- 8 mV S.D.), action potential amplitude (77 +/- 11.8 mV) duration (1.4 +/- 0.5 ms) and afterpotentials, were effectively identical in the neurons recorded from the two preparations. Neurons in both preparations when activated with long-duration (1-2 s) outward current pulses showed a single steady-state firing range with little adaptation of firing frequency or action potential amplitude. This pattern of responses was unaffected by changing the membrane potential. Orthodromic synaptic activity could be elicited in the neurons by stimulating either the small dorsal root remnants in the slice or the dorsal roots in the hemisected spinal cord. The responses evoked by single stimuli of increasing intensity varied in different neurons in both preparations. The commonest response (32/62) consisted of a short-latency, short-duration composite excitatory postsynaptic potential which generated one or two spikes with no further spiking activity at longer latency when the stimulus intensity was increased beyond threshold. In 20 neurons, graded stimulation produced a graded response with recruitment, at high intensities, of a discharge of action potentials lasting several hundred milliseconds. A small number of cells (4) responded to the single stimulus with a train of action potentials lasting several seconds. Stimulating adjacent dorsal roots in the hemisected cord preparation could evoke quite different responses from the neurons. The heterogeneity of the types of orthodromic responses obtained in both preparations, in spite of the almost uniform intrinsic membrane properties, is likely to reflect differences in the strength, location and type of afferent and interneuronal input to different dorsal horn cells.
    背景与目标: : 已在体外研究了大鼠脊髓深背角 (laminae iii-vi) 中87个神经元的电生理特性。已使用两种制剂; 来自14-16天大的大鼠 (71个细胞) 的第三或第四腰椎节段的横向脊髓切片制剂和来自10-12天大的大鼠 (16个细胞) 的半腰脊髓制剂。输入阻抗 (范围11-128 M omega),膜电位 (-67 +/- 8 mV s.d.),动作电位振幅 (77 +/- 11.8 mV) 持续时间 (1.4 +/- 0.5 ms) 和后电位,两种制剂记录的神经元实际上是相同的。用长时间 (1-2 s) 的向外电流脉冲激活时,两种制剂中的神经元均显示出单一的稳态发射范围,几乎不适应发射频率或动作电位幅度。这种反应模式不受改变膜电位的影响。通过刺激切片中的小背根残余物或半脊髓中的背根,可以在神经元中引发正畸突触活动。在两种制剂中,强度增加的单个刺激引起的反应在不同的神经元中有所不同。最常见的反应 (32/62) 由短潜伏期,短持续时间的复合兴奋性突触后电位组成,当刺激强度增加超过阈值时,在更长的潜伏期产生一个或两个尖峰,而没有进一步的尖峰活动。在20个神经元中,分级刺激产生了分级反应,并在高强度下募集了持续数百毫秒的动作电位放电。少数细胞 (4) 对单个刺激有反应,持续了几秒钟的动作电位。在半切除的脐带制剂中刺激相邻的背根可能会引起神经元的完全不同的反应。尽管具有几乎均匀的固有膜特性,但在两种制剂中获得的正畸反应类型的异质性可能反映了不同背角细胞的传入和神经元输入的强度,位置和类型的差异。
  • 【肠左旋多巴/卡比多巴输注作为帕金森氏病深部脑刺激后无反应冻结步态的治疗选择。】 复制标题 收藏 收藏
    DOI:10.1155/2020/1627264 复制DOI
    作者列表:González-Herrero B,Jauma-Classen S,Gómez-Llopico R,Plans G,Calopa M
    BACKGROUND & AIMS: Background:Treatment of freezing of gait (FOG) is always challenging because of its unpredictable nature and multifactorial physiopathology. Intestinal levodopa infusion has been proposed in recent years as a valuable option for its improvement. FOG in Parkinson's disease (PD) can appear after deep brain stimulation in patients who never had gait symptoms. Objective:To study the effects of intestinal levodopa/carbidopa infusion in unresponsive-FOG that appears in PD patients treated with subthalamic nucleus deep brain stimulation. Methods:We retrospectively collected and analyzed demographic, clinical, and therapeutic data from five PD patients treated with subthalamic nucleus stimulation who developed unresponsive-FOG and received intestinal levodopa/carbidopa infusion as an alternative therapy. FOG was measured based on scores in item 14 of the Unified Parkinson's Disease Rating Scale before and after intestinal levodopa infusion. Results:Administration of intestinal levodopa caused improvement of FOG in the "ON" state in four patients (80%) by 2 or more points in item 14 of the Unified Parkinson's Disease Rating Scale. The improvement was maintained for at least 12 months. Conclusions:Intestinal levodopa infusion may be a valuable therapeutic option for unresponsive-FOG developed after subthalamic nucleus deep brain stimulation.
    背景与目标:
  • 【基底神经节、运动障碍和深部脑刺激: 通过非人类灵长类动物研究取得的进展。】 复制标题 收藏 收藏
    DOI:10.1007/s00702-017-1736-5 复制DOI
    作者列表:Wichmann T,Bergman H,DeLong MR
    BACKGROUND & AIMS: :Studies in non-human primates (NHPs) have led to major advances in our understanding of the function of the basal ganglia and of the pathophysiologic mechanisms of hypokinetic movement disorders such as Parkinson's disease and hyperkinetic disorders such as chorea and dystonia. Since the brains of NHPs are anatomically very close to those of humans, disease states and the effects of medical and surgical approaches, such as deep brain stimulation (DBS), can be more faithfully modeled in NHPs than in other species. According to the current model of the basal ganglia circuitry, which was strongly influenced by studies in NHPs, the basal ganglia are viewed as components of segregated networks that emanate from specific cortical areas, traverse the basal ganglia, and ventral thalamus, and return to the frontal cortex. Based on the presumed functional domains of the different cortical areas involved, these networks are designated as 'motor', 'oculomotor', 'associative' and 'limbic' circuits. The functions of these networks are strongly modulated by the release of dopamine in the striatum. Striatal dopamine release alters the activity of striatal projection neurons which, in turn, influences the (inhibitory) basal ganglia output. In parkinsonism, the loss of striatal dopamine results in the emergence of oscillatory burst patterns of firing of basal ganglia output neurons, increased synchrony of the discharge of neighboring basal ganglia neurons, and an overall increase in basal ganglia output. The relevance of these findings is supported by the demonstration, in NHP models of parkinsonism, of the antiparkinsonian effects of inactivation of the motor circuit at the level of the subthalamic nucleus, one of the major components of the basal ganglia. This finding also contributed strongly to the revival of the use of surgical interventions to treat patients with Parkinson's disease. While ablative procedures were first used for this purpose, they have now been largely replaced by DBS of the subthalamic nucleus or internal pallidal segment. These procedures are not only effective in the treatment of parkinsonism, but also in the treatment of hyperkinetic conditions (such as chorea or dystonia) which result from pathophysiologic changes different from those underlying Parkinson's disease. Thus, these interventions probably do not counteract specific aspects of the pathophysiology of movement disorders, but non-specifically remove the influence of the different types of disruptive basal ganglia output from the relatively intact portions of the motor circuitry downstream from the basal ganglia. Knowledge gained from studies in NHPs remains critical for our understanding of the pathophysiology of movement disorders, of the effects of DBS on brain network activity, and the development of better treatments for patients with movement disorders and other neurologic or psychiatric conditions.
    背景与目标: : 对非人类灵长类动物 (NHPs) 的研究在我们对基底节的功能以及运动不足性疾病 (如帕金森氏病) 和运动亢进性疾病 (如舞蹈病和肌张力障碍) 的病理生理机制的理解方面取得了重大进展。由于NHPs的大脑在解剖学上与人类的大脑非常接近,因此与其他物种相比,疾病状态以及医学和外科手术方法 (例如深部脑刺激 (DBS)) 的影响可以在NHPs中更忠实地建模。根据受NHPs研究强烈影响的当前基底神经节回路模型,基底神经节被视为分离网络的组成部分,这些网络来自特定的皮质区域,穿过基底神经节和腹侧丘脑,然后返回额叶皮层。根据所涉及的不同皮质区域的假定功能域,这些网络被指定为 “运动”,“眼动”,“关联” 和 “边缘” 电路。这些网络的功能受到纹状体中多巴胺释放的强烈调节。纹状体多巴胺的释放会改变纹状体投射神经元的活性,进而影响 (抑制性) 基底神经节的输出。在帕金森氏病中,纹状体多巴胺的丧失导致基底神经节输出神经元放电的振荡爆发模式的出现,相邻基底神经节神经元放电的同步性增加以及基底神经节输出的总体增加。在帕金森氏症的NHP模型中,在丘脑底核 (基底神经节的主要组成部分之一) 水平上的运动回路失活的抗帕金森氏效应的证明了这些发现的相关性。这一发现也有力地促进了手术干预治疗帕金森氏病患者的复兴。虽然消融程序最初是为此目的使用的,但现在已被丘脑下核或苍白球内部节段的DBS所取代。这些程序不仅可有效治疗帕金森氏症,而且可有效治疗多动性疾病 (例如舞蹈病或肌张力障碍),这些疾病是由与帕金森氏病不同的病理生理变化引起的。因此,这些干预措施可能不会抵消运动障碍的病理生理学的特定方面,而是非特异性地消除了基底神经节下游运动电路相对完整部分中不同类型的破坏性基底神经节输出的影响。从NHPs研究中获得的知识对于我们了解运动障碍的病理生理学,DBS对脑网络活动的影响以及为运动障碍和其他神经或精神疾病患者开发更好的治疗方法仍然至关重要。
  • 【在视网膜分支静脉阻塞中使用光谱域OCT测量神经节细胞内网状层厚度的可重复性。】 复制标题 收藏 收藏
    DOI:10.1007/s00417-017-3710-1 复制DOI
    作者列表:Lee YH,Kim MS,Ahn SI,Park HJ,Shin KS,Kim JY
    BACKGROUND & AIMS: PURPOSE:To analyze the repeatability of thickness measurements of the central macula, ganglion cell-inner plexiform layer (GC-IPL), and retinal nerve fiber layer (RNFL) using spectral-domain optical coherence tomography (SD-OCT) before and after treatment of macular edema in branch retinal vein occlusion (BRVO). METHODS:We analyzed patients with BRVO who visited our retinal clinic. The repeatability of the thickness measurements were compared using the intraclass correlation coefficient (ICC) and coefficient of variation (COV) of affected versus normal fellow eyes. RESULTS:The average thicknesses of the central macula, RNFL, and GC-IPL were 371.28 μm, 105.60 μm, and 61.88 μm, respectively, in affected eyes with macular edema before treatment, and the ICCs were 0.978, 0.919, and 0.705, respectively. The average thicknesses were 244.98 μm, 96.70 μm, and 82.70 μm, respectively, in affected eyes without macular edema after treatment, and the ICCs were 0.999, 0.975, and 0.928, respectively. After resolution of macular edema, the average thickness of the GC-IPL increased, whereas that of the central macula and RNFL significantly decreased (P < 0.05); all of the ICCs increased compared to pretreatment values. In normal fellow eyes, the average thicknesses were 250.98 μm, 93.50 μm, and 83.84 μm, respectively, and the ICCs were 0.996, 0.995, and 0.994, respectively. CONCLUSIONS:After treatment of macular edema, the repeatability and thickness of the GC-IPL increased, along with reduction in the central macular thickness. This resulted from auto-segmentation errors following macular contour changes and unstable gazes of the patients due to decreased visual acuities in BRVO with macular edema.
    背景与目标:

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