Socio-economic factors affecting the conservation of natural woodlands in Central Riyadh Area – Saudi Arabia

This study aimed to identify some socioeconomic factors affecting local people in central Riyadh area for the utilization of wood and other energy sources in cooking and heating in order to develop some recommendations for conserving woodlands. The study results revealed that gas is the most common energy source used for cooking with a mean usage level of 2.79 (SD = 0.58). On the other hand, wood ranked first for heating with the highest mean, usage level of 1.90 (SD = 1.06). However, electricity and gas as sources of energy for heating ranked second and third with mean usage level of 1.81 and 0.80 respectively. The study revealed that local people with the university education were significantly making higher use of electricity for both cooking and heating and those with no formal education ranked the highest on wood use for both cooking and heating. In addition, those living in traditional houses significantly used more wood for cooking than those living in villas and apartments. Also, local people with high income levels significantly were using more electricity for heating than others. The study recommended conducting extension and environmental awareness raising programs to enhance local residents’ adoption of wood substitutes, promoting employment opportunities for unemployed locals, and subsidizing prices of alternative energy sources.     

Sherborn’s foraminiferal studies and their influence on the collections at the Natural History Museum,London

Sherborn’s work on the Foraminifera clearly provided the initial spark to compile the major indexes for which he is famous. Contact and help from famous early micropalaeontologists such as T. Rupert Jones and Fortescue William Millett led Sherborn to produce his Bibliography of Foraminifera and subsequently a two-part Index of Foraminiferal Genera and Species. Edward Heron-Allen, whose mentor was Millett, was subsequently inspired by the bibliography to attempt to acquire every publication listed. This remarkable collection of literature was donated to the British Museum (Natural History) in 1926 along with the foraminiferal collections Heron-Allen had mainly purchased from early micropalaeontologists. This donation forms the backbone of the current NHM micropalaeontological collections. The NHM collections contain a relatively small amount of foraminiferal material published by Sherborn from the London Clay, Kimmeridge Clay and Speeton Clay. Another smaller collection reflects his longer-term interest in the British Chalk following regular fieldwork with A. W. Rowe. Other collections relating to Sherborn’s early published work, particularly with T. R. Jones, are not present in the collections but these collections may have been sold or deposited elsewhere by his co-workers.     

自然杀伤细胞参与肝脏恶性肿瘤免疫逃逸研究进展

自然杀伤细胞是机体固有免疫系统重要组成部分,在肝脏等免疫器官中含量丰富,而且免疫表型、功能等表现出器官特异性。在正常情况下,靶细胞表面的配体与自然杀伤细胞表面的活化性受体直接结合并释放细胞毒性物质,诱导活化靶细胞凋亡程序,从而发挥抗感染、抗肿瘤作用。然而肿瘤细胞仍能够通过多种途径逃逸机体的免疫监视功能,研究认为肿瘤细胞抗原异常表达、肿瘤微环境中细胞因子及其他免疫细胞相互作用等因素所引起的自然杀伤细胞活性降低对于诱导肿瘤免疫逃逸起重要作用。本文综述了自然杀伤细胞在肝脏恶性肿瘤发生过程中参与免疫逃逸的机制及研究进展,以期为临床抗肿瘤免疫治疗的研究提供参考。     

基于专利分析的天然抗肿瘤药制剂技术发展态势研究

目的:基于专利文献深入分析天然抗肿瘤药制剂技术的发展态势。方法:采用专利计量分析、统计学趋势分析等定量分析方法结合药学专业知识的定性分析方法从专利申请数量、国家/地区分布、专利技术领域等方面对天然抗肿瘤药制剂技术领域的发展态势进行分析。结果:天然抗肿瘤药制剂技术专利年申请数量在3000件左右,处于比较稳定平稳的发展时期;专利申请主要集中在美国和中国;专利技术领域主要集中在抗肿瘤活性和剂型的相关研究。结论:美国专利申请数量排名第一,远远领先于其他国家,且专利质量很高,处于绝对的领先地位。中国虽然在专利申请数量方面具有一定优势,但是专利质量亟待提高,与国外发达国家相比仍有较大差距。     

Dry/wet variations in the eastern Tien Shan (China) since AD 1725 based on Schrenk spruce (Picea schrenkiana Fisch. et Mey) tree rings

Cores of Schrenk spruce from seven sites of eastern Tien Shan were used to develop a regional tree-ring chronology to extend the climate record. We developed an August–July Standardized Precipitation Evapotranspiration Index (SPEI) reconstruction that spans AD 1725–2013 based on the regional tree-ring chronology. The reconstruction model accounts for 45.3% of the SPEI variance from 1959 to 2013. The SPEI reconstruction agrees reasonably well with the dry and wet periods previously estimated from tree rings in northern Xinjiang. The correlation analysis revealed that temperature plays an important role in regional drought variability, and some extreme wet years also coincide with the volcanic eruptions.     

Land use impacts on stream community composition and concordance along a natural stress gradient

Most ecosystems are subjected to multiple stressors derived from natural and anthropogenic sources and community responses to human disturbance in naturally stressful habitats may differ from those in more benign habitats. We examined the influence of a natural (geology-driven acidity) vs. human-induced stress (land drainage) and their interaction on the composition and concordance of stream diatom, bryophyte and invertebrate communities. To account for differing drainage impacts in circumneutral (sedimentation) and naturally acid (reduced pH and increased metal concentrations) streams we investigated concordance in three groups of streams: reference (circumneutral and naturally acidic reference), circumneutral (reference and drained) and naturally acidic (reference and drained) streams. We expected diatoms to respond more strongly to anthropogenic acidification and more weakly to sedimentation compared to bryophytes and invertebrates. We expected overall strong concordance among the three taxonomic groups, but especially so in reference streams. All three organism groups had distinct species composition in naturally acidic vs. circumneutral streams. Concordance between communities was overall strong, especially so in the reference streams. All groups responded to drainage disturbance in both types of streams. Invertebrates were slightly less responsive to increased acidification in the naturally acidic streams but were more affected by sedimentation in the circumneutral streams than were the other two groups. The natural stressor affected communities more than the anthropogenic stressors. Naturally stressed communities were affected by an anthropogenic stressor as much as those in more benign habitats, although the additional stressor was similar to the initial stress (further reduction of stream pH). Naturally acid streams may need special concern in bioassessment because models based on circumneutral reference sites will likely produce biased predictions for these streams.     

Development of a preclinical natural porcine knee simulation model for the tribological assessment of osteochondral grafts in vitro

In order to pre-clinically evaluate the performance and efficacy of novel osteochondral interventions, physiological and clinically relevant whole joint simulation models, capable of reproducing the complex loading and motions experienced in the natural knee environment are required. The aim of this study was to develop a method for the assessment of tribological performance of osteochondral grafts within an in vitro whole natural joint simulation model.The study assessed the effects of osteochondral allograft implantation (existing surgical intervention for the repair of osteochondral defects) on the wear, deformation and damage of the opposing articular surfaces. Tribological performance of osteochondral grafts was compared to the natural joint (negative control), an injury model (focal cartilage defects) and stainless steel pins (positive controls). A recently developed method using an optical profiler (Alicona Infinite Focus G5, Alicona Imaging GmbH, Austria) was used to quantify and characterise the wear, deformation and damage occurring on the opposing articular surfaces. Allografts inserted flush with the cartilage surface had the lowest levels of wear, deformation and damage following the 2 h test; increased levels of wear, deformation and damage were observed when allografts and stainless steel pins were inserted proud of the articular surface. The method developed will be applied in future studies to assess the tribological performance of novel early stage osteochondral interventions prior to in vivo studies, investigate variation in surgical precision and aid in the development of stratified interventions for the patient population.     

Regioselective and efficient enzymatic synthesis of antimicrobial andrographolide derivatives

Labdane diterpene andrographolide (1) is a major constituent of Andrographis paniculata and known to exhibit wide spectrum of biological activities. In this study, regioselective monoesters of (1) have been synthesized by using Amano lipase AK (Pseudomonas fluorescens) as a biocatalyst. Amano lipase AK was able to execute highly efficient esterification of hydroxyl group attached to C-14 carbon of (1) in presence of acyl donors. Among the various synthesized derivatives including two novel compounds such as andrographolide-14-propionate (3) and andrographolide-14-caproate (5) displayed antimicrobial activity against Staphylococcus aureus with low minimal inhibitory concentration (MIC) 4?µg/mL and 16?µg/mL respectively. Furthermore, they have shown low hemolysis activity at their respective MIC and increase in the permeability of the bacterial cell membrane as delineated by FITC uptake and SEM imaging studies.     

Structure-activity relationships of cryptopleurine analogs with E-ring modifications as anti-hepatitis C virus agents

The tylophorine analog rac-cryptopleurine exhibited potent anti-hepatitis C virus (HCV) activity through allosteric regulation of ATPase activity of heat shock cognate protein 70 (Hsc70). We evaluated the impact of modifications on the E-ring of rac-cryptopleurine to the inhibitory activity against HCV replication and regulation of ATPase activity of Hsc70. Cryptopleurine analog YXM-110 with a 13α-hydroxyl group maintained activity against HCV and promoted ATP/ADP turnover of Hsc70; however, compounds with hydroxyl groups at other positions or with other orientations (YXM-109, YXM-139, and YXM-140) did not exhibit similar activities. Size modification or heteroatom incorporation of the E-ring led to loss of anti-HCV activity. Promotion of the chaperone activity of Hsc70 with carboxyl terminus Hsc70 interacting protein (CHIP) further enhanced the anti-HCV activity of rac-cryptopleurine and XYM-110. This structure-activity relationship (SAR) study refined structural design and optimization for developing rac-crytopleurine analogs as potent anti-HCV agents targeted against the host factor involved in HCV replication.