Comparative regional-scale soil salinity assessment with near-ground apparent electrical conductivity and remote sensing canopy reflectance

Soil salinity is recognized worldwide as a major threat to agriculture, particularly in arid and semi-arid regions. Producers and decision makers need updated and accurate maps of salinity in agronomically and environmentally relevant ranges (i.e., <20 dS m⁻¹, when salinity is measured as electrical conductivity of the saturation extract, EC_e). State-of-the-art approaches for creating accurate EC_e maps beyond field scale (i.e., 1 km²) include: (i) Analysis Of Covariance (ANOCOVA) of near-ground measurements of apparent soil electrical conductivity (EC_a) and (ii) regression modeling of multi-year remote sensing canopy reflectance and other co-variates (e.g., crop type, annual rainfall). This study presents a comparison of the two approaches to establish their viability and utility. The approaches were tested using 22 fields (total 542 ha) located in California’s western San Joaquin Valley. In 2013 EC_a-directed soil sampling resulted in the collection of 267 soil samples across the 22 fields, which were analyzed for EC_e, ranging from 0 to 38.6 dS m⁻¹. The ANOCOVA EC_a-EC_e model returned a coefficient of determination (R²) of 0.87 and root mean square prediction error (RMSPE) of 3.05 dS m⁻¹. For the remote sensing approach seven years (2007–2013) of Landsat 7 reflectance were considered. The remote sensing salinity model had R² = 0.73 and RMSPE = 3.63 dS m⁻¹. The robustness of the models was tested with a leave-one-field-out (lofo) cross-validation to assure maximum independence between training and validation datasets. For the ANOCOVA model, lofo cross-validation provided a range of scenarios in terms of RMSPE. The worst, median, and best fit scenarios provided global cross-validation R² of 0.52, 0.80, and 0.81, respectively. The lofo cross-validation for the remote sensing approach returned a R² of 0.65. The ANOCOVA approach performs particularly well at EC_e values <10 dS m⁻¹, but requires extensive field work. Field work is reduced considerably with the remote sensing approach, but due to the larger errors at low EC_e values, the methodology is less suitable for crop selection, and other practices that require accurate knowledge of salinity variation within a field, making it more useful for assessing trends in salinity across a regional scale. The two models proved to be viable solutions at large spatial scales, with the ANOCOVA approach more appropriate for multiple-field to landscape scales (1–10 km²) and the remote sensing approach best for landscape to regional scales (>10 km²).     

Horticultural mineral oil influences Plum pox virus transmission by Myzus persicae

The residual activity of horticultural mineral oil (HMO) on the ability of green peach aphids, Myzus persicae (Sulzer), (GPA) to transmit Plum pox virus (PPV) to peach was measured by infection rates of detached leaves from plants sprayed with either HMO or water as a control that were inoculated using transfer of 25 viruliferous aphids per leaf at 0, 2, 4, 7, 9, 11 and 14 days after treatment (DAT). Persistent effects of HMO residue on the probing and feeding behaviours of GPA were also monitored with the electrical penetration graph (EPG) system. For glasshouse‐grown peach seedlings, the residual activity of HMO reduced PPV infection rates by more than 58% for up to 4 DAT following an initial reduction of approximately 81%. EPG recordings of GPA feeding behaviour showed that HMO significantly delayed first feeding probes and first intracellular punctures by more than 50 min without changing the ensuing stylet penetration behaviour. Applying HMO reduced virus infection rates for up to a week depending on the environmental conditions. EPG monitoring of aphid probing showed that HMO reduced the mean duration and mean number of potential drop (PD) phase feeding occurrences, compared with the water control. A reduction in the PD that has been shown to be related to the transmission of non‐persistently transmitted viruses may partly explain the reduction in PPV infection rates.     

经皮穴位电刺激对老年髋关节置换术患者脑氧代谢以及术后认知功能、镇痛效果的影响

目的:探讨经皮穴位电刺激(TEAS)对老年髋关节置换术患者脑氧代谢以及术后认知功能、镇痛效果的影响。方法:选取2016年1月～2018年7月期间我院收治的行髋关节置换术患者91例为研究对象,将研究对象根据随机数字表法分为对照组(n=45)和研究组(n=46),对照组给予常规麻醉处理,研究组在对照组基础上给予TEAS,比较两组脑氧代谢、术后认知功能以及镇痛效果,记录两组术后的不良反应发生情况。结果:在降压开始后20 min(T1)、降压开始后40 min(T2)、停止降压后20 min(T3)时间点时,两组静脉血氧含量(Cjv O2)较降压前即刻(T0)时间点升高,且研究组高于对照组(P0.05),两组脑动-静脉血氧含量差(Da-jvO2)、脑氧摄取率(CERO2)较T0时间点降低,且研究组低于对照组(P0.05)。两组患者术后72h简易智能量表(MMSE)评分均较术前24h降低,但研究组高于对照组(P0.05),研究组术后认知功能障碍(POCD)发生率低于对照组(P0.05)。与术前比较,两组患者术后8h、术后24h、术后48h视觉疼痛模拟量表(VAS)评分均升高(P0.05),但研究组术后8h、术后24h、术后48h等时间点VAS评分均低于对照组(P0.05)。两组患者不良反应总发生率比较无差异(P0.05)。结论:TEAS对老年髋关节置换术后患者的镇痛效果确切,可有效改善脑氧代谢情况,提高术后认知功能,临床应用价值较高。     

Co‐utilization of acidified glycerol pretreated‐sugarcane bagasse for microbial oil production by a novel Rhodosporidium strain

Acidified glycerol pretreatment is very effective to deconstruct lignocellulosics for producing glucose. Co‐utilization of pretreated biomass and residual glycerol to bioproducts could reduce the costs associated with biomass wash and solvent recovery. In this study, a novel strain Rhodosporidium toruloides RP 15, isolated from sugarcane bagasse, was selected and tested for coconversion of pretreated biomass and residual glycerol to microbial oils. In the screening trails, Rh. toruloides RP 15 demonstrated the highest oil production capacity on glucose, xylose, and glycerol among the 10 strains. At the optimal C:N molar ratio of 140:1, this strain accumulated 56.7, 38.3, and 54.7% microbial oils based on dry cell biomass with 30 g/L glucose, xylose, and glycerol, respectively. Furthermore, sugarcane bagasse medium containing 32.6 g/L glucose from glycerol‐pretreated bagasse and 23.4 g/L glycerol from pretreatment hydrolysate were used to produce microbial oils by Rh. toruloides RP 15. Under the preliminary conditions without pH control, this strain produced 7.7 g/L oil with an oil content of 59.8%, which was comparable or better than those achieved with a synthetic medium. In addition, this strain also produced 3.5 mg/L carotenoid as a by‐product. It is expected that microbial oil production can be significantly improved through process optimization.     

Selection and optimization of a suitable pretreatment method for miscanthus and poplar raw material

Miscanthus and poplar are very promising second‐generation feedstocks due to the high growth rates and low nutrient demand. The aim of the study was to develop a systematic approach for choosing suitable pretreatment methods evaluated with the modified severity factor (log ). Optimal pretreatment results in a high delignification grade, low cellulose solubilization and increased accessibility for enzymatic hydrolysis while revealing minimal log values. In order to do so, several reaction approaches were compared. Acid‐catalyzed organosolv processing carried out for miscanthus and poplar revealed the highest delignification grade leading to a relatively high glucose yield after enzymatic saccharification. In both cases, a design of experiments approach was used to study the influence of relevant parameters. Modeling the data resulted in the identification of optimum pretreatment conditions for miscanthus with concentrations of 0.16% H₂SO₄ and 50% EtOH at 185°C for a retention time of 60 min. Experimental validation of these conditions revealed an even higher delignification degree (88%) and glucose yield (85%) than predicted. 0.19% H₂SO₄ and 50% EtOH were determined as optimum concentrations, 182°C and 48 min identified as optimum pretreatment conditions for poplar; the delignification degree was 84% and the resulting glucose yield 70%.     

布比卡因致心肌细胞线粒体损伤大鼠模型的建立

目的观察电刺激下布比卡因心肌细胞线粒体形态变化及活性氧(reactive oxygen species, ROS)生成量,探讨建立理想的布比卡因中毒的大鼠心肌细胞模型。方法采用Langendroff装置新鲜分离雄性SD大鼠心肌细胞,细胞计数后将其转移至doff管中随机分为四组:DMEM静置组、DMEM电刺激组、布比卡因静置组、布比卡因电刺激组。实验重复五次。采用透射电镜观察心肌细胞线粒体形态,并使用多功能微孔板检测仪测量ROS生成量。结果 DMEM电刺激组线粒体肿胀程度及ROS生成量与DMEM静置组相比差异无显著性(P> 0.05);而布比卡因电刺激组线粒体肿胀程度明显高于布比卡因静置组(P=0.000),且ROS生成量也明显升高(P<0.05)。结论电刺激下心肌细胞呈节律性收缩,能更好地模拟临床布比卡因中毒时心肌线粒体损伤。     

Muscle oxygenation dynamics in response to electrical stimulation as measured with near‐infrared spectroscopy: A pilot study

Neuromuscular electrical stimulation (NMES) is used for preventing muscle atrophy and improving muscle strength in patients and healthy people. However, the current intensity of NMES is usually set at a level that causes the stimulated muscles to contract. This typically causes pain. Quantifying the instantaneous changes in muscle microcirculation and metabolism during NMES before muscle contraction occurs is crucial, because it enables the current intensity to be optimally tuned, thereby reducing the NMES‐induced muscle pain and fatigue. We applied near‐infrared spectroscopy (NIRS) to measure instantaneous tissue oxygenation and deoxygenation changes in 43 healthy young adults during NMES at 10, 15, 20, 25, 30, and 35 mA. Having been stabilized at the NIRS signal baseline, the tissue oxygenation and total hemoglobin concentration increased immediately after stimulation in a dose‐dependent manner (P < 0.05) until stimulation was stopped at the level causing muscle contraction without pain. Tissue deoxygenation appeared relatively unchanged during NMES. We conclude that NIRS can be used to determine the optimal NMES current intensity by monitoring oxygenation changes.      

Preparation and application of freeze-dried platelets

Clinical platelet infusion is primarily used to prevent or stop bleeding, but can also have a role in treating infections or promoting wound healing. The demand for platelets has increased in recent years. However, as platelets can only be stored for short periods, there is a substantial loss due to the products reaching their expiry date. Platelet lyophilization is a particularly valuable and important research field. The purpose of studying the freeze-drying preservation of platelets is to realize the long-term preservation of platelets at room temperature. It is very possible to prepare qualified freeze-dried platelets. However, there are still problems that have not been solved in the process of platelet lyophilization. This review mainly summarizes research progress in the preparation and application of freeze-dried platelets.     

Pushing, pulling and trapping--modes of motor protein supported protein translocation

Protein translocation across the cellular membranes is an ubiquitous and crucial activity of cells. This process is mediated by translocases that consist of a protein conducting channel and an associated motor protein. Motor proteins interact with protein substrates and utilize the free energy of ATP binding and hydrolysis for protein unfolding, translocation and unbinding. Since motor proteins are found either at the cis- or trans-side of the membrane, different mechanisms for translocation have been proposed. In the Power stroke model, cis-acting motors are thought to push, while trans-motors pull on the substrate protein during translocation. In the Brownian ratchet model, translocation occurs by diffusion of the unfolded polypeptide through the translocation pore while directionality is achieved by trapping and refolding. Recent insights in the structure and function of the molecular motors suggest that different mechanisms can be employed simultaneously.     

Plant regeneration via direct somatic embryogenesis in Panax japonicus

Panax japonicus is one of the important medicinal plants. Here, we established the protocol for plant regeneration of P. japonicus via direct somatic embryogenesis. Somatic embryos were directly obtained from the segments of zygotic embryos on MS medium with 4.4 μM 2,4-D. Thereafter, somatic embryos were produced by repetitive secondary somatic embryogenesis. The secondary somatic embryo formation was enhanced by plasmolyzing pretreatment (1.0 M mannitol for 10 h). Frequency of secondary somatic embryo formation from cotyledon segments was lowered by plasmolyzing pretreatment, but the number of somatic embryos per explants was greatly increased. Plasmolyzing pretreatment resulted in retardation of embryo growth and required subculture to fresh medium for further growth of embryos into cotyledonary stage. Without plasmolyzing pretreatment, cotyledonary embryos were obtained after 8 weeks of culture. All the cotyledonary somatic embryos germinated by 5 μM GA₃ treatment, but only 15.3% were germinated on hormone-free medium. After 2 months of culture on 1/2 strength WPM medium, plantlets produced flowers spontaneously. In the anthers of in vitro flowers, microsporogenesis occurred normally with low number of pollen grains.