Properties of the HtrA Protease From Bacterium Helicobacter pylori Whose Activity Is Indispensable for Growth Under Stress Conditions

The protease high temperature requirement A from the gastric pathogen Helicobacter pylori (HtrAHp) belongs to the well conserved family of serine proteases. HtrAHp is an important secreted virulence factor involved in the disruption of tight and adherens junctions during infection. Very little is known about the function of HtrAHp in the H. pylori cell physiology due to the lack of htrA knockout strains. Here, using a newly constructed ΔhtrA mutant strain, we found that bacteria deprived of HtrAHp showed increased sensitivity to certain types of stress, including elevated temperature, pH and osmotic shock, as well as treatment with puromycin. These data indicate that HtrAHp plays a protective role in the H. pylori cell, presumably associated with maintenance of important periplasmic and outer membrane proteins. Purified HtrAHp was shown to be very tolerant to a wide range of temperature and pH values. Remarkably, the protein exhibited a very high thermal stability with the melting point (Tm) values of above 85°C. Moreover, HtrAHp showed the capability to regain its active structure following treatment under denaturing conditions. Taken together, our work demonstrates that HtrAHp is well adapted to operate under harsh conditions as an exported virulence factor, but also inside the bacterial cell as an important component of the protein quality control system in the stressed cellular envelope

Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

Comparison of two inoculation methods of endophytic bacteria to enhance phytodegradation efficacy of an aged petroleum hydrocarbons polluted soil

Endophyte-enhanced phytodegradation is a promising technology to clean up polluted soils. To improve the success rate of this nature-based remediation approach, it is important to advance the inoculation method as this has been shown to strongly affect the final outcome. However, studies evaluating inoculation strategies and their effect on hydrocarbon degradation are limited. This study aims to investigate two different manners of endophyte inoculation in Lolium perenne growing in an aged petroleum hydrocarbon polluted soil: (1) direct soil inoculation (SI), and (2) pre-inoculation of the caryopses followed by soil inoculation (PI). Different endophytic bacterial strains, Rhodococcus erythropolis 5WK and Rhizobium sp. 10WK, were applied individually as well as in combination. Depending on the method of inoculation, the petroleum hydrocarbon (PHC) degradation potential was significantly different. The highest PHC removal was achieved after pre-inoculation of ryegrass caryopses with a consortium of both bacterial strains. Moreover, both strains established in the aged-polluted soil and could also colonize the roots and shoots of L. perenne. Importantly, used endophytes showed the selective colonization of the environment compartments. Our findings show that the method of inoculation determines the effciency of the phytodegradation process, especially the rate of PHC degradation. This study provides valuable information for choosing the most cost-effective and beneficial means to optimize phytodegradation

Outer Membrane Vesicles as Mediators of Plant–Bacterial Interactions

Plants have co-evolved with diverse microorganisms that have developed different mechanisms of direct and indirect interactions with their host. Recently, greater attention has been paid to a direct “message” delivery pathway from bacteria to plants, mediated by the outer membrane vesicles (OMVs). OMVs produced by Gram-negative bacteria play significant roles in multiple interactions with other bacteria within the same community, the environment, and colonized hosts. The combined forces of innovative technologies and experience in the area of plant–bacterial interactions have put pressure on a detailed examination of the OMVs composition, the routes of their delivery to plant cells, and their significance in pathogenesis, protection, and plant growth promotion. This review synthesizes the available knowledge on OMVs in the context of possible mechanisms of interactions between OMVs, bacteria, and plant cells. OMVs are considered to be potential stimulators of the plant immune system, holding potential for application in plant bioprotection

Role of pressure in stabilization of oxynitride phosphor synthesis

The possibilities of improving the crystallization and optical properties of strontium europium oxonitridosilicate phosphor powders were discussed. Two different routes of synthesis were presented: traditional solid-state reaction method and gas pressure synthesis. It was proven that altering the partial pressure during the process of synthesis enhances crystallization of a desired single, triclinic SrSi2O2N2 phase. XANES measurements confirmed complete reduction of the trivalent europium activator ions in all of the tested materials. The photoluminescent properties were determined by emission, excitation and decay times measurements. CIE1931 colour points and luminous efficacy were calculated as well. Thermal quenching studies in the range of 0-225 degrees C confirmed good thermal stability of the investigated powders combined with excellent quantum efficiency at room temperature

The Role of Forkhead Box O in Pathogenesis and Therapy of Diabetes Mellitus

Type 2 diabetes is a disease that causes numerous complications disrupting the functioning of the entire body. Therefore, new treatments for the disease are being sought. Studies in recent years have shown that forkhead box O (FOXO) proteins may be a promising target for diabetes therapy. FOXO proteins are transcription factors involved in numerous physiological processes and in various pathological conditions, including cardiovascular diseases and diabetes. Their roles include regulating the cell cycle, DNA repair, influencing apoptosis, glucose metabolism, autophagy processes and ageing. FOXO1 is an important regulator of pancreatic beta-cell function affecting pancreatic beta cells under conditions of insulin resistance. FOXO1 also protects beta cells from damage resulting from oxidative stress associated with glucose and lipid overload. FOXO has been shown to affect a number of processes involved in the development of diabetes and its complications. FOXO regulates pancreatic β-cell function during metabolic stress and also plays an important role in regulating wound healing. Therefore, the pharmacological regulation of FOXO proteins is a promising approach to developing treatments for many diseases, including diabetes mellitus. In this review, we describe the role of FOXO proteins in the pathogenesis of diabetes and the role of the modulation of FOXO function in the therapy of this disease

RORC2 Genetic Variants and Serum Levels in Patients with Rheumatoid Arthritis

Background: In the present study, we aimed to evaluate whether polymorphisms within the RORc2 gene are involved in the risk and severity of rheumatoid arthritis (RA). Methods: 591 RA patients and 341 healthy individuals were examined for RORc2 gene polymorphisms. Serum retinoic acid receptor-related orphan receptor C (RORc) levels were measured by enzyme-linked immunosorbent assay (ELISA). Results: The rs9826 A/G, rs12045886 T/C and rs9017 G/A RORc2 gene SNPs show no significant differences in the proportion of cases and control. Overall, rs9826 and rs9017 were in high linkage disequilibrium (LD) with D’ = 0.952 and r2 = 0.874, except rs9826 and rs12045886; and rs12045886 and rs9017 in weak LD. The genotype–phenotype analysis showed a significant association between RORc2 rs9826 A/G and rs9017 G/A single nucleotide polymorphisms (SNPs) and median of C-reactive protein (CRP). Serum RORc levels was higher in RA patients with rs9826AA, rs12045886TT and -TC, and rs9017AA genotypes compared to healthy subjects with the same genotypes (p = 0.02, p = 0.04 and p = 0.01, respectively). Moreover, the median of RORc protein level was higher in RA patients with number of swollen joints bigger then 3 (p = 0.04) and with Health Assessment Questionnaires (HAQ) score bigger then 1.5 (0.049). Conclusions: Current findings indicated that the RORc2 genetic polymorphism and the RORc2 protein level may be associated with severity of RA in the Polish population