Spatial and temporal trends in nitrate concentrations in the River Derwent, North Yorkshire, and its need for NVZ status

Long-term spatial and temporal variations in nitrate-N concentrations along the River Derwent have been examined using Environment Agency data to investigate the relative importance of impacts of atmospheric N deposition, land use, and changes in management. Where moorland and rough grazing dominate upstream of Forge Valley and Malton, over the 20 years since 1988 mean nitrate-N concentrations were initially increasing significantly, but are now levelling off, with peaks at ca. 4.5 mg N l⁻¹. As expected in a catchment in a nitrate vulnerable zone (NVZ), more agricultural land use increases mean nitrate concentrations and the occurrence of distinct winter maxima, though the latter have become markedly less pronounced since 2001. It is suggested that this improvement is a combined effect of imposition of NVZ designation in the lower reaches in 2002, animal number declines associated with the Foot & Mouth outbreak in the region in 2001, and the impact of farmers' responses to increasing fertilizer prices and to beneficial pollutant mineral N inputs from the atmosphere. Minima in nitrate-N concentrations in summer have become much less pronounced over the past decade and are typically ca. 60% higher in concentration than a decade earlier. This probably is attributable to the effects of pollutant-N leaching to depths in soil below the rooting zone when near surface biotic uptake is low in winter. The resultant N mineralization in summer enhances summer nitrate leaching. The Derwent is a relatively clean river; however, its entire catchment was designated justifiably as a NVZ in January 2009, apparently based upon a projected 95 percentile nitrate-N concentration > 11.29 mg l^− 1 for 2010 based upon forward projection of data from 1990 to 2004 for Derwent Bridge. A survey of water quality in March 2009 showed that some agricultural areas are still making a significant contribution to the total nitrate level well downstream, at the point responsible for implementation of NVZ status. At 3 of the 29 sites sampled, nitrate concentration exceeded 60 mg l^− 1.     

Use of Impella cardiac axial flow pump for cardiogenic shock (A newer alternative)–How good is the evidence?

The adverse outcomes of a ventricular heart failure (left, right or biventricular) caused by cardiogenic shock are aggravated by lung oedema and organ mal perfusion. Despite advances in medical sciences, revascularisation and mechanical hemodynamic support have proved ineffective in reducing the mortality rate in such patients. A thorough study of the data available about cardio-vascular diseases reveals that the application of conventional methods of treatment are least helpful to practically restore normal functions of heart when it experiences end-stage systolic ventricular failure. Thus, to overcome the challenges and find alternatives to address this issue, percutaneous ventricular support devices/machines were designed and successfully introduced. These devices have revolutionized the treatment of ventricular heart failures and are now in use all over the world. In this review paper a newer mechanical circulatory support (MCS) device, Impella, has been discussed and compared with a few other devices like (Intra-aortic Balloon Pump (IABP), Extracorporeal Circulation (ECLS) and Veno-arterial Extracorporeal Membrane Oxygenation (VA-ECMO). This article studies the challenges being faced during the treatment of cardiogenic shock, and thoroughly discusses the use and effectiveness of Impella Cardiac Axial Pump in each emergency. It can be said that mechanical circulatory support (MCS) device use during percutaneous coronary intervention (PCI) should be individualized based on multiple factors with a recommended use in patients with the greatest potential benefit and a relatively low risk of device-related complications. The current literature suggests that the outcomes of use of Impella and other mechanical circulatory support devices like IABP and VA-ECMO are comparable. Though there seem to be a few advantages of Impella over the others, sufficiently powered, multi-centric, randomised control trials are needed to establish its superiority.     

Role of foliar spray of plant growth regulators in improving photosynthetic pigments and metabolites in <i>Plantago ovata</i> (Psyllium) under salt stress–A field appraisal

Salinity is one of the major abiotic factors that limit the growth and productivity of plants. Foliar application of plant growth regulators (PGRs) may help plants ameliorate the negative impacts of salinity. Thus, a field experiment was conducted at the Botanical Garden University of Balochistan, Quetta, to explore the potential role of PGRs, i.e., moringa leaf extract (MLE; 10%), proline (PRO; 1 µM), salicylic acid (SA; 250 µM), and thiourea (TU; 10 mM) in ameliorating the impacts of salinity (120 mM) on Plantago ovata, an important medicinal plant. Salinity hampered plant photosynthetic pigments and metabolites but elevated oxidative parameters. However, foliar application of PGRs enhanced photosynthetic pigments, including Chl b (21.11%), carotenoids (57.87%) except Chl a, activated the defense mechanisms by restoring and enhancing the metabolites, i.e., soluble sugars (49.68%), soluble phenolics (33.34%), and proline (31.47%), significantly under salinity stress. Furthermore, foliar supplementation of PGRs under salt stress led to a decrease of about 43.02% and 43.27% in hydrogen peroxide and malondialdehyde content, respectively. Thus, PGRs can be recommended for improved photosynthetic efficiency and metabolite content that can help to get better yield under salt stress, with the best and most effective treatments being those of PRO and MLE to predominately ameliorate the harsh impacts of salinity.     

Interleukin-1 receptor antagonist: From synthesis to therapeutic applications

The cytokine channel’s mechanism for self-regulation involves the application of antagonistic cytokines that are synthesized to connect to the receptors and release soluble cytokine receptors. The very first receptor antagonist of cytokine that was naturally present was interleukin-1 receptor antagonist (IL-1Ra). The IL-1Ra protein forms are disinfected from supernatants of cultured monocytes on stacked IgG. The family of IL-1 consists of IL-1α, IL-1β and IL-1Ra. Human monocytes regulate the production of IL-Ra. IL-Ra takes part in normal physiological functions by using specific antibodies, and acts as an anti-inflammatory agent. IL-Ra is synthesized in the tissues during the period of active disease and can be systematically measured and/or estimated. Maintenance of the levels of IL-Ra and IL-1 is the main factor for host resistance in patients during diseased conditions, as IL-Ra acts as an inherent regulator of various inflammatory responses. In this article, we focuse on how IL-Ra is synthesized and performs its functions once the inflammatory responses are activated.     

石墨烯纳米片增强铝基复合材料的制备与性能

采用高能球磨、放电等离子烧结以及热挤压工艺制备含量为5.0％(体积分数)的石墨烯增强铝基复合材料.分别采用X射线光电子能谱、透射电镜及拉伸试验研究挤压态复合材料的显微组织与力学性能,发现5.0％(体积分数)的石墨烯分散在铝晶界上,并且未与铝基体发生界面反应.最终,挤压态复合材料的屈服强度和抗拉强度高达462 MPa和4...     

Effect of particle size on thermal decomposition and devolatilization kinetics of melon seed shell

Thermogravimetric analysis (TGA) and devolatilization kinetics of melon seed shell (MSS) at different particle sizes (150?µm and 500?µm) and at different heating rates (10, 15, 20, and 25?°C/min) were investigated with the aid of TGA. The results of the TGA analysis show that the TGA curves corresponding to the first and third stages for 150?µm particle sizes exhibited some bumps that developed at the first and third stages of pyrolysis. It was also observed that at constant heating rate, the maximum peak temperature increases as the particle sizes increase from 150 to 500?µm, whereas 500?µm particle sizes exhibited higher peak temperatures compared to 150?µm particle sizes. The resulting TGA data were applied to the Kissinger (K), Kissinger–Akahira–Sunose (KAS) and Flynn–Wall–Ozawa (FWO) methods and kinetic parameters (activation energy, E and frequency factor, A) were determined. The E and A obtained using K method were 74.27?kJ mol^?1 and 3.84?×?10⁵?min^?1 for 150?µm particle size, whereas for 500?µm particle size were 97.12?kJ mol^?1 and 3.74?×?10⁷?min^?1, respectively. However, the average E and A obtained using KAS and FWO methods were 82.35?kJ mol^?1, 1.29?×?10⁷?min^?1, and 88.50?kJ mol^?1, 1.32?×?10⁷?min^?1 for 150?µm particle sizes. While for 500?µm particle sizes, the E and A were 108.46?kJ mol^?1, 3.14?×?10⁹?min^?1, and 113.05?kJ mol^?1, 7.56?×?10⁹?min^?1, respectively. It was observed that E and A calculated from FWO and KAS methods were very close and higher than that obtained by K method. It was observed that the minimum heat required for the cracking of MSS particles into products is reached later at higher peak temperatures since the heat transfer is less effective as they are at lower peak temperatures.     

The growth of pine-leaf-like hierarchical SnO2 nanostructures

Pine-leaf-like SnO₂ hierarchical nanostructures (NSs) were grown by a two-step vapour transport deposition process with a combination of vapour–solid and vapour–liquid–solid mechanisms at the primary and secondary processes, respectively. This type of hierarchical structure consisted of SnO₂ trunk with homo-branching nanowires (NWs). The branched NWs connected the trunk NWs at included angles of 56° and 90° for two different types of hierarchical NSs. Based on the thermodynamic calculation, the formation of branched NWs at those angles are all energetically favourable.     

Modelling the current—voltage characteristic of a fluorescent lamp for computer-aided design

An empirical formula is presented for the voltage-current characteristics of a fluorescent lamp. The three parameters of the formula can easily be obtained from the measured characteristics of the fluorescent lamp without recourse to conventional curve-fitting techniques. By using this formula the analytical study of electronic circuits incorporating fluorescent lamps can be simplified.     

（英）W波段InP HBT 宽带高功率压控振荡器

本文介绍了一款具有较高输出功率和宽调谐频率范围的基波压控振荡器单片集成电路。其制作工艺为f_T =170GHz,f_max =250GHz的0.8um InP DHBT工艺。电路核心部分采用了平衡式考毕兹振荡器拓扑,并在后面添加了一级缓冲放大器来抑制负载牵引效应,并提升了输出功率。DHBT的反偏CB结作为变容二极管来实现频率调谐。芯片测量结果表明,VCO的频率调谐范围为81- 97.3GHz,相对带宽为18.3 %。在调谐频率范围内最大输出功率为10.5 dBm,输出功率起伏在3.5 dB以内。在该VCO的最大调谐频率97.3 GHz处相位噪声为-88 dBc/Hz @1MHz。在目前所报道的InP HBT基VCO MMIC中,本文在如此宽的频率调谐范围内实现了最高的输出功率。