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Tin phosphide (Sn-P) based materials, comprising abundant elements on the earth, have attracted much attention as anodes for alkali-ion batteries. As one of the emerging families of tin phosphides, Sn4P3 is fast becoming a vital alternative anode for next-generation alkali-ion batteries mainly owing to its stable phase, appropriate operating potential, and high theoretical capacity. However, the fast capacity decay caused by the volume changes and Sn agglomeration greatly hinder its practical application. Thus, the tremendous effect has been made the address the above issues. Herein, we retrospect the development of Sn-P anode using Sn4P3 as an indicator and categorize the implemented methods to solve the problem of Sn4P3 in published work into four strategies, which are designing hierarchical/hollow nanostructures, constructing robust physical barriers of carbonaceous materials, doping or introducing heterophase interfaces, and modifying the solid-electrolyte interphase (SEI) layer. Besides, the application of the proposed strategies in other Sn-P based materials (e.g., SnP3 and SnP) in alkali-ion batteries were discussed. Finally, the remained challenges and perspectives for Sn-P based anodes of alkali-ion batteries were presented. This review systematically retrospect the progress of Sn-P materials, which not only will promote the development of Sn-P based anodes but also help to generate fresh insight into similar alloy-based materials.

A number of strategies have been proposed to deal with intrinsic sulfur problems in lithium–sulfur batteries, while the most representative and effective strategy is the utilization of porous carbon as a sulfur container. However, it should be admitted that conventional preparation routes for porous carbon are complicated and generally involve high-temperature processing, which increases the cost and production difficulty. In this work, a facile hydrothermal tactic was put forward to fabricate oxidized porous carbon materials (OPCBs) for lithium–sulfur (Li–S) batteries. The specific surface area of OPCBs and the size of the formed pores could be flexibly adjusted by regulating hydrothermal conditions, simultaneously retaining the intact structure of the particles, even without seriously affecting the conductivity of carbon/sulfur composites in some OPCBs. Polar interfaces introduced by hydrothermal processing could immobilize long-chain lithium polysulfide via the chemical interaction, whereas the appearance of micro–mesoporous structure played a critical role in physical restrictions of sulfur species and offered a more rapid lithium-ion transmission pathway during cycling. As a result, the optimized OPAB-140-1.5@S delivered a superior comprehensive cycle performance, which maintained quite an impressive reversible capacity of 602 mA h g−1, even after 400 cycles with a low decay rate of 0.08% per cycle. In addition, the tailor-made pore structures with different characteristics prepared by the straightforward technique provide some enlightenment on the potential orientation to multi-field applications.

Beyond reasonable designing catalysts, the optimization of preparing air cathode has far-reaching implications for the development of Zinc-air batteries. In this study, the effect of Polytetrafluoroethylene (PTFE) in current collecting layer on the performance of Zinc-air battery was investigated. The results showed that as the polytetrafluoroethylene (PTFE) content and heat treatment temperature changed, the hydrophobicity and porosity of current collecting layer also changed, thereby affecting the performance of air cathode. The air cathode assembled with PTFE-3-300 possessed an excellent electrochemical performance, which was prepared by brushing PTFE and acetylene black (wherein the mass ratio of them is 18:5) on current collecting layer and then heating at 300 °C. The obtained air cathode displayed relatively small polarization loss and excellent rate performance, showing a polarization potential of - 0.405 V vs. Hg/HgO at 100 mA cm−2 and the voltage retention of 94.47% from 5 to 20 mA cm−2. Besides, the air cathode displayed excellent discharge stability maintaining average potential 1.3249 V for 100 h. Based on this work, a detailed understanding of the relationship of PTFE and current collecting layer can be achieved to improve the electrode design, architecture and fabrication.

The catalyst in the oxygen electrode is the core component of the aqueous metal-air battery, which plays a vital role in the determination of the open circuit potential, energy density, and cycle life of the battery. For rechargeable aqueous metal-air batteries, the catalyst should have both good oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalytic performance. Compared with precious metal catalysts, non-precious metal materials have more advantages in terms of abundant resource reserves and low prices. Over the past few years, great efforts have been made in the development of non-precious metal bifunctional catalysts. This review selectively evaluates the advantages, disadvantages and development status of recent advanced materials including pure carbon materials, carbon-based metal materials and carbon-free materials as bifunctional oxygen catalysts. Preliminary improvement strategies are formulated to make up for the deficiency of each material. The development prospects and challenges facing bifunctional catalysts in the future are also discussed.

Additional file 1: Table 1. Distribution ofvirulence scores by source and fluoroquinolone (FQ) resistance phenotypeamongst Escherichia coli ST131isolates from children and women.

Additional file 1: Table S1. Novel oligonucleotide probes and primers developed for the mPCR/RLB assay for detection of uropathogenic E. coli virulence factor genes.

Hui Xu,1,* Shu-Ying Yu,2–4,* Meng-Lan Zhou,2–4 Ya-Ting Ning,2–4 Meng Xiao,2,4 Xiao-Gai Li,1 Meng Chen,2,5 Fanrong Kong,6 Sharon Chen,6 Liang Ming,1 Ying-Chun Xu2,3 1Department of Clinical Laboratory, The First Affiliated Hospital of Zhengzhou University and Key Laboratory of Clinical Laboratory of Henan Province, Henan 450003, People’s Republic of China; 2Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, People’s Republic of China; 3Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, People’s Republic of China; 4Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, People’s Republic of China; 5Department of Clinical Laboratory, Beijing Pinggu Hospital of Traditional Chinese Medicine, Beijing 101200, People’s Republic of China; 6Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR – New South Wales Health Pathology, The University of Sydney, Westmead Hospital, Westmead, NSW, Australia*These authors contributed equally to this workCorrespondence: Liang MingDepartment of Clinical Laboratory, The First Affiliated Hospital of Zhengzhou University, 1E Jianshe Road, Zhengzhou, Henan 450052, People’s Republic of ChinaTel +86 371 6691 3118Email mingliang3072@163.com Ying-Chun XuDepartment of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, No.1 Shuaifuyuan, Wangfujing, Dongcheng District, Beijing 100730, People’s Republic of ChinaTel/Fax +86 10 6915 9766Email xycpumch@139.comIntroduction: As participants of the national China Hospital Invasive Fungal Surveillance Net program, we sought to describe the epidemiology and antifungal susceptibility patterns of yeast isolates obtained from patients with invasive fungal infection at the First Affiliated Hospital of Zhengzhou University, China.Methods: A total of 434 yeast isolates recovered from blood and other sterile body fluids were identified to species by matrix-assisted laser desorption ionization –time of flight mass spectrometry with or without supplementation by DNA sequencing. Antifungal susceptibilities were determined by Sensititre YeastOneTM YO10 methodology.Results: Candida albicans was the most common causative species (33.9% of isolates) but significantly decreased in frequency from 37.2% to 27.7% from 2012 to 2014. C. tropicalis was the next most common pathogen (25.1%), followed by C. parapsilosis complex (17.3%), C. glabrata (9%), and C. pelliculosa (6.7%), with other species comprising 8% of isolates. Caspofungin, micafungin, and anidulafungin exhibited potent in vitro activities against the majority of Candida isolates. Azoles demonstrated in vitro activities against C. albicans with a susceptibility rate of >95% and against C. parapsilosis complex, >95% isolates were susceptible. Among C. tropicalis and C. glabrata isolates, resistance rates to fluconazole and voriconazole were 11.9%, 9.1% and 7.7%, 28.2%, respectively. Of note, C. pelliculosa had a high incidence rate in newborns and high rates of resistance to fluconazole and voriconazole of 55.2% and 41.4%, respectively.Conclusion: The present study provided valuable local surveillance data on the epidemiology and antifungal susceptibilities of invasive yeast species, which is essential for guiding antifungal treatment protocol development.Keywords: invasive yeast infection, epidemiology, antifungal susceptibility

As the developing of UHV project, the environmental factors put forward much higher requirements for the design, operation and maintenance of UHV AC transformer. The lowest temperature in winter of northern area in our country can reach −40° C, in order to study its influence on insulation margin of transformer, the changing rules of dielectric parameters of each material in transformer at low temperature have been tested in this paper. And its effect on the distribution of electric field in main insulation has been analyzed by simulation method. Eventually, the change of insulation margin of main insulation in transformer at different temperature has also been calculated. The research results show that the relatively dielectric constant of oil increases linearly with the decrease of temperature, and that of oil-impregnated pressboard decreases exponentially on the contrary. Nevertheless, their breakdown strength shows the same trend of falling firstly and then rising as the temperature increasing, and reaches the valley value at −10°C, which is more serious for oil. Moreover, the simulation result shows that the electric field distribution transfers to oil in oil-paper insulation system, and insulation margin decreases firstly and then increases as the temperature decreasing, which also reaches the minimum value at −10°C. Considering the dielectric characteristic, it can be concluded the electric field distribution, especially the insulation margin of oil in compound insulation should be confirmed at −10°C during the design process of transformer.

Shu-Ying Yu,1–3 Li Zhang,1,3 Sharon Chen,4 Fanrong Kong,4 Meng Xiao,1,3 He Wang,1,3 Xin Hou,1–3 Meng-Lan Zhou,1–3 Ge Zhang,1,3 Jing-Jia Zhang,1,3 Si-Meng Duan,1,3 Wei Kang,1,3 Ying-Chun Xu1,31Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, People’s Republic of China; 2Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, People’s Republic of China; 3Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, People’s Republic of China; 4Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR –New South Wales Health Pathology, The University of Sydney, Westmead, New South Wales, AustraliaIntroduction: We studied the species distribution and antifungal susceptibilities of Candida isolates causing refractory or recurrent oropharyngeal candidiasis (OPC) in a multicenter study in China (2013–2016).Methods: Species identification was performed using the Bruker Biotyper (Bruker Daltonics, Germany) matrix-assisted laser desorption/ionization time of flight mass spectrometry system supplemented by internal transcribed spacer sequencing as required. Antifungal susceptibilities were determined by the Clinical and Laboratory Standards Institute document (CLSI) M27-A3 broth microdilution methodology.Results: A total of 558 non-duplicate Candida isolates comprising 10 species were obtained from 535 patients. Candida albicans was the most common species (89.6%), followed by C. glabrata (5.2%), C. tropicalis (2.9%), and C. parapsilosis (0.7%). Azoles were active against C. albicans with susceptibility rates of 96% and 95.8% for fluconazole and voriconazole, respectively. MIC50 values of C. albicans to fluconazole, voriconazole, itraconazole, and miconazole were 1, 0.03, 0.25 and 0.12 μg/mL, respectively, higher than those in previous studies of which OPC patients (corresponding MIC50 values of 0.25 , 0.015 , 0.06 , and 0.03 μg/mL). Except for itraconazole, the MIC50 and MIC90 values of 58 non-C. albicans to other azoles were two to threefold higher than C. albicans. Miconazole, amphotericin B, nystatin, and 5-flucytosine had good in vitro antifungal activity for all isolates.Conclusion: The study provides valuable data on the species distribution and antifungal susceptibility of oropharyngeal Candida isolates from geographically diverse areas of China. C. albicans remains the most common species but with increasing rates of azoles resistance.Keywords: oral candidiasis, Candida, identification, antifungal susceptibility

China’s pumped storage power station has a broad prospect, in which salient pole synchronous motor plays an important role. In this paper, the mathematical expression of electromagnetic force in the case of short circuit of the excitation winding of salient pole synchronous motor is derived, and the variation law of electromagnetic force density in the case of fault corresponding to the electromagnetic force of damping winding is calculated. The mathematical law of electromagnetic force in the case of short circuit fault of salient pole synchronous motor is revealed, which has practical reference significance.

In recent ten years, China’s pumped storage power station has developed rapidly. As the core component of pumped storage unit, salient pole synchronous motor is very important to study its abnormal operation. In this paper, taking salient pole synchronous motor as the research object, the mathematical expressions of magnetomotive force for single-phase short circuit to ground, phase to phase short circuit and two-phase short circuit to ground are derived respectively, and the mathematical law of magnetomotive force for short circuit fault of salient pole synchronous motor under generating condition is revealed. It provides a basis for fault diagnosis, related research and calculation of salient pole synchronous motor.

Shu-Ying Yu,1–3 Li-Na Guo,1,3 Meng Xiao,1,3 Timothy Kudinha,4,5 Fanrong Kong,4 He Wang,1,3 Jing-Wei Cheng,1–3 Meng-Lan Zhou,1–3 Hui Xu,6 Ying-Chun Xu1–3 1Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China; 2Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China; 3Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, China; 4Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR – Pathology West, University of Sydney, Westmead Hospital, Westmead, NSW, Australia; 5Centre for Infectious Diseases and Microbiology Laboratory Services, Westmead Hospital, Westmead, NSW, Australia; 6Department of Clinical Laboratory, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China Background: Trichosporon dohaense is a rare fungal species that has not been described in human invasive infections. Patients and methods: In this study, we investigated two T. dohaense isolates from patients with invasive infections in two hospitals in China, as part of the China Hospital Invasive Fungal Surveillance Net (CHIF-NET) program. Both patients were under immunocompromised conditions. Results: On chromogenic agar, T. dohaense isolates were dark blue, similar to the color of Candida. tropicalis, but the characteristic moist colony appearance was quite different from that of T.asahii. The two isolates were misidentified as T. asahii and T. inkin by the VITEK 2 YST system. The rDNA internal transcribed spacer (ITS) region and the D1/D2 domain sequences of the two T.dohaense isolates were 100% identical to T. dohaense type strain CBS10761T. The sequence of the intergenic spacer region-1 also clearly distinguished the species. Of the three matrix-assisted laser desorption/ionization time-of-flight mass spectrometry systems, Bruker Biotyper and Autobio MS correctly identified the two isolates to species level, whereas Vitek MS systems misidentified them as T. ovoides or T. asteroides. Echinocandins exhibited no in vitro activities against the two T. dohaense isolates. In addition, the isolates exhibited intermediate susceptibility to fluconazole (with minimal inhibitory concentrations [MICs] of 8 and 16 µg/mL) and itraconazole, voriconazole, and posaconazole (MICs of 0.25–1 µg/mL). T. dohaense demonstrated susceptibility to amphotericin B with MIC of 1 µg/mL. The MICs of fluconazole and voriconazole in our study were higher than the MIC50 of 62 for T. asahii isolates (4 and 0.064 µg/mL) in the CHIF-NET program. Conclusion: This case study points to a possible emergence of T. dohaense as an opportunistic human invasive fungal pathogen, and the reduced susceptibility should be noted. Keywords: Trichosporon dohaense, invasive infection, emerging pathogen, identification, reduced susceptibility

Meng Xiao,1,2,* Xin Fan,1–3,* Xin Hou,1,2,4,* Sharon CA Chen,5 He Wang,1,2 Fanrong Kong,5 Zi-Yong Sun,6,* Yun-Zhuo Chu,7 Ying-Chun Xu1,2 1Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, People’s Republic of China; 2Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, People’s Republic of China; 3Department of Infectious Diseases and Clinical Microbiology, Beijing Chaoyang Hospital, Beijing, People’s Republic of China; 4Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People’s Republic of China; 5Center for Infectious Diseases and Microbiology Laboratory Services, ICPMR, New South Wales Health Pathology, Westmead Hospital, The University of Sydney, NSW, Australia; 6Department of Clinical Laboratory, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, People’s Republic of China; 7Department of Clinical Laboratory, The First Affiliated Hospital of Chinese Medical University, Shenyang, People’s Republic of China *These authors contributed equally to this work Abstract: Echinocandin antifungal agents have become the first-line therapy for invasive candidiasis (IC) in many countries. Despite their increasing use, resistance to this class of drug is, overall, still uncommon. Here, we report two patients from the People’s Republic of China with IC, one with infection caused by pan-echinocandin-resistant Candida tropicalis and the other by pan-echinocandin-resistant Candida glabrata. We also describe the mechanisms of drug resistance of these isolates. The echinocandin-resistant C. glabrata isolate was cultured from ascitic fluid of a 46-year-old male patient with intra-abdominal IC developing after surgery in 2012. This patient had had no prior antifungal exposure. The echinocandin-resistant C.tropicalis isolate was cultured from chest drainage fluid of a 60-year-old female patient with severe coronary disease and lung infection. Prior to culture and identification of the isolate, the patient had received micafungin treatment for 19 days. Both isolates were cross-resistant to micafungin, anidulafungin, and caspofungin, with minimum inhibitory concentration values of ≥2 µg/mL. The amino acid substitution E655K was found adjacent to the FKS2 HS1 region of the C. glabrata isolate, while the substitution S80P were found in the FKS1 HS1 region of the C. tropicalis isolate. This report highlights the emergence of echinocandin resistance in two important non-albicans Candida species. Although the overall prevalence of echinocandin resistance is low in the People’s Republic of China, monitoring of antifungal susceptibility trends in all Candida species is warranted. Keywords: Candida tropicalis, Candida glabrata, echinocandins, antifungal resistance, People’s Republic of China

Meng Xiao,1,* Jing-Wei Cheng,1,2,* Timothy Kudinha,3 Fanrong Kong,4 Ying-Chun Xu1,21Department of Clinical Laboratory, Peking Union Medical College Hospital, 2Faculty of Clinical Laboratory Diagnostics, Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China; 3School of Biomedical Sciences, The Charles Sturt University, Leeds Parade, Orange, 4Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR–Pathology West, Westmead Hospital, University of Sydney, Westmead, NSW, Australia*These authors contributed equally to this workIn a recent report, Dingle et al showed that national intervention programs aimed at judicious antimicrobial usage, especially restrictions to fluoroquinolones, contributed to a significant decrease in Clostridium difficile infection (CDI) in England.1 This is considered an outstanding achievement in combating antimicrobial resistance worldwide.

Rapid and accurate detection of multidrug resistance (MDR) inMycobacterium tuberculosisis essential to improve treatment outcomes and reduce global transmission but remains a challenge. Rifampin (RIF) resistance is a reliable marker of MDR tuberculosis (TB) since by far the majority of RIF-resistant strains are also isoniazid (INH) resistant. We have developed a rapid, sensitive, and specific method for detecting the most common mutations associated with RIF resistance, in the RIF resistance determining region (RRDR) ofrpoB, using a cocktail of six padlock probes and rolling circle amplification (RCA). We used this method to test 46 storedM. tuberculosisclinical isolates with known RIF susceptibility profiles (18 RIF resistant, 28 susceptible), a standard susceptible strain (H37Rv, ATCC 27294) and 78M. tuberculosisculture-positive clinical (sputum) samples, 59 of which grew RIF-resistant strains. All stored clinical isolates were correctly categorized, by the padlock probe/RCA method, as RIF susceptible or resistant; the sensitivity and specificity of the method, for direct detection of phenotypically RIF-resistantM. tuberculosisin clinical specimens, were 96.6 and 89.5%, respectively. This method is rapid, simple, and inexpensive and has the potential for high-throughput routine screening of clinical specimens for MDRM. tuberculosis, particularly in high prevalence settings with limited resources. a grant from The National S&T Major Special Project on Major New Drug Innovation (2012ZX09301002-005-003) from the Ministry of Science and Technology of China

In this study, the phylogenetic relationships between the two biovars and 14 serovars of Ureaplasma urealyticum were studied using the sequences of four different genes or genetic regions, namely: 16S rRNA genes; 16S-23S rRNA gene spacer regions; urease gene subunits ureA, ureB, partial ureC and adjoining regions upstream of ureA, ureA-ureB spacer and ureB-ureC spacer; the 5'-ends of the multiple-banded antigen (MBA) genes. U. urealyticum genotypes, based on all four genomic sequences, could be clearly separated into two clusters corresponding with currently recognized biovars 1 and 2. Sequences were generally conserved within each biovar. However, there was heterogeneity within the 5'-end regions of the MBA genes of the four serovars of biovar 1; the sequence of serovar 3 was identical with the previously published sequence and differed by only three bases from that of serovar 14; but there were significant differences between the sequences of serovars 3 and 14 and those of serovars 1 and 6. Based on the phylogenetic analysis, support is given to previous recommendations that the two biovars of U. urealyticum be classified as distinct species, namely U. parvum and U. urealyticum for biovars 1 and 2, respectively. In the future, the relationship between the new species and clinical manifestations of ureaplasma infections should be studied.

The recent emergence of multidrug-resistantEscherichia colisequence type 131 (ST131) has coincided with an increase in general antibiotic resistance ofE. coli, suggesting that ST131 has a contributing role in resistance. However, there is little information about the contribution of ST131 to different clinical syndromes or the basis for its impressive emergence and epidemic spread. To investigate this, we studied 953E. coliisolates from women of reproductive age in the central west region of New South Wales, Australia, including 623 urinary isolates from patients with cystitis (cystitis isolates) (n 322) or pyelonephritis (pyelonephritis isolates) (n 301) and 330 fecal isolates from healthy controls. The characteristics studied included ST131 clonal group status, resistance to different antibiotics, presence of virulence factor (VF) genes, and biofilm production. As expected, fecal isolates differed significantly from urinary (cystitis and pyelonephritis) isolates in most of the studied characteristics. Antibiotic resistance was significantly more common in ST131 than in non-ST131 isolates. Both antibiotic resistance and ST131 were more common in pyelonephritis than cystitis isolates and least so among fecal isolates. Within each source group, individual VF genes were more prevalent and VF scores were higher for ST131 than for non-ST131 isolates. For ST131 only, the prevalences of most individual VF genes and VF scores were the lowest in the fecal isolates, higher in the cystitis isolates, and highest in the pyelonephritis isolates. Biofilm production was strongly associated with ST131 status and antibiotic resistance. These results clarify the distribution of the ST131 clonal group and its epidemiological associations in our region and suggest that it exhibits both enhanced virulence and increased antibiotic resistance compared with those of other urinary tract infection (UTI) and fecalE. coliisolates from women of reproductive age Office of Research and Development, Medical Research Service, Department of Veterans Affairs, grant no. 1 I01 CX000192 01 (to J.R.J.).

Human γD-crystallin (HγD-Crys) is a highly stable protein that remains folded in the eye lens for the majority of an individual's lifetime. HγD-Crys exhibits two homologous crystallin domains, each containing two Greek key motifs with eight β-strands. Six aromatic pairs (four Tyr/Tyr, one Tyr/Phe and one Phe/Phe) are present in the β-hairpin sequences of the Greek keys. Ultraviolet damage to the aromatic residues in lens crystallins may contribute to the genesis of cataract. Mutant proteins with these aromatic residues substituted with alanines were constructed and expressed in E. coli. All mutant proteins except F115A and F117A had lower thermal stability than the WT protein. In equilibrium experiments in guanidine hydrochloride (GuHCl), all mutant proteins had lower thermodynamic stability than the WT protein. N-terminal domain (N-td) substitutions shifted the N-td transition to lower GuHCl concentration, but the C-terminal domain (C-td) transition remained unaffected. C-td substitutions led to a more cooperative unfolding/refolding process, with both the N-td and C-td transitions shifted to lower GuHCl concentration. The aromatic pairs conserved for each Greek key motif (Greek key pairs) had larger contributions to both thermal stability and thermodynamic stability than the other pairs. Aromatic-aromatic interaction was estimated as 1.5-2.0 kcal/mol. In kinetic experiments, N-td substitutions accelerated the early phase of unfolding, while C-td substitutions accelerated the late phase, suggesting independent domain unfolding. Only substitutions of the second Greek key pair of each crystallin domain slowed refolding. The second Greek keys may provide nucleation sites during the folding of the double-Greek-key crystallin domains.

Group B streptococcus (GBS, S. agalactiae) and human ureaplasmas (U. parvumand U. urealyticum) are two clinically and phylogenetically related, potential perinatal pathogens. Their relationships between genotypes and pathogenesis of GBS and ureaplasma infection were still not well understood, one of the reason is that both of them are still short of a very practical genotyping system. In the study, to solve the above problem we developed genotyping systems for the organisms (the second section). For human ureaplasmas, based on four genes/gene clusters (rRNAgene clusters, the elongation factor Tu genes, urease gene complexes and multiplebanded antigen genes), we designed many primer pairs suitable for developing species identification assays for the two newly established human ureaplasma species (U. parvum and U. urealyticum). Further, based on the heterogeneity of ureaplasma multiple banded antigen gene (which contains species- and serovar-specific regions), we developed genotyping methods for each ureaplasma species.For GBS, based on three sets of molecular markers (capsular polysaccharidesynthesis gene clusters, surface protein antigen genes and mobile genetic elements),we developed a genotyping system. The primary evaluation of the genotyping systems showed that the genotyping systems were practical alternative assays for the conventional serotyping and they will be useful to further explore the relationships between genotypes and pathogenesis of GBS and ureaplasma infection. In the study, we introduced novel data and tools into GBS and ureaplasma studies especially from genomic- and bioinformatics-based molecular microbiology(the third section). For two newly established human ureaplasma species, based on the U. parvum serovar-3 genome, and using the above four important genes/geneclusters, we exposed some interesting problems in the understanding of newureaplasma taxonomy especially in the post genomic era. For GBS, we studied the two published full genomes and exposed some new problems or possible future new research fields. In particular we found the two finished and one ongoing GBS genomes were all non-typical and suggest that future genomic project had better have genetic population structure viewpoint. Finally, we suggested that integrated studies of the two potential or conditional perinatal pathogens, from the viewpoint of evolution, would provide a new understanding angle of the pathogenesis of the two organisms. Studies suggested that during coevolution, human ureaplasmas(especially U. parvum) became friendlier than their ancestors to their human host (by losing most of its virulence genes); however, GBS tried to increase its invasive abilities (by getting more virulence genes) to fight against the human host attack.