Stiefel-Whitney topological charges in a three-dimensional acoustic nodal-line crystal.

Band topology of materials describes the extent Bloch wavefunctions are twisted in momentum space. Such descriptions rely on a set of topological invariants, generally referred to as topological charges, which form a characteristic class in the mathematical structure of fiber bundles associated with the Bloch wavefunctions. For example, the celebrated Chern number and its variants belong to the Chern class, characterizing topological charges for complex Bloch wavefunctions. Nevertheless, under the space-time inversion symmetry, Bloch wavefunctions can be purely real in the entire momentum space; consequently, their topological classification does not fall into the Chern class, but requires another characteristic class known as the Stiefel-Whitney class. Here, in a three-dimensional acoustic crystal, we demonstrate a topological nodal-line semimetal that is characterized by a doublet of topological charges, the first and second Stiefel-Whitney numbers, simultaneously. Such a doubly charged nodal line gives rise to a doubled bulk-boundary correspondence-while the first Stiefel-Whitney number induces ordinary drumhead states of the nodal line, the second Stiefel-Whitney number supports hinge Fermi arc states at odd inversion-related pairs of hinges. These results experimentally validate the two Stiefel-Whitney topological charges and demonstrate their unique bulk-boundary correspondence in a physical system.

[Qualitative research on pain experiences of adult burn patients].

Objective: To explore the pain experiences of adult burn patients so as to lay foundation for practical analgesic measures. Methods: Using phenomenological method in qualitative research, semi-structured interviews were conducted on 12 adult burn patients hospitalized in our burn units from May to November 2015, aiming at pain experiences from immediately after burns to 3 to 7 months after being discharged from hospital. Then the Colaizzi's analysis method was applied to analyze, induce, and refine themes of interview data. Results: After analysis, pain experiences of adult burn patients were generalized into 6 themes: deep pain experiences, heavy psychological burden, limited daily life, poor assessment and treatment of pain, different attributions of pain, and different ways of coping of pain. Conclusions: Burn pain brings harm to the patients' physiology, mentality, and daily life. Nevertheless, pain processing modes of medical staff and patients themselves are the key factors affecting patients' pain experiences. Therefore, according to the deficiency of current situation of pain management, the targeted analgesic intervention measures should be carried out from the perspectives of medical staff and patients.

[Analysis of distribution and drug resistance of pathogens isolated from 541 hospitalized children with burn infection].

Objective: To investigate the distribution and drug resistance of pathogens isolated from hospitalized children with burn infection. Methods: Totally 541 patients were hospitalized in Fujian Medical University Union Hospital, the 180th Hospital of Chinese People's Liberation Army(PLA), the 92th Hospital of PLA, and Longyan First Hospital from January 2013 to December 2015. Totally 848 clinical specimens (blood, catheter tip attachments, wound exudate, etc.) were collected for pathogen detection. After being identified by an automatic microbiological identification system, drug resistance of pathogens to 41 commonly-used antibiotics in clinic including gentamicin, aztreonam, erythromycin, clindamycin, etc. was tested by K-B paper disk diffusion method or minimal inhibitory concentration detection method. The SPSS 20.0 statistical software was used to analyze the following subjects: the detection rates of pathogens in different years, from different hospitals, and with different sources, the distribution of gram-negative bacteria, gram-positive bacteria, and fungi, the distribution of major pathogens, the detection rate of methicillin-resistant Staphylococcus, the resistant rates of common gram-positive bacteria and gram-negative bacteria to antibiotics. Results: The total detection rate of pathogens was 35.14% (298/848). The detection rates of pathogens were 52.29% (114/218), 33.20% (83/250), and 26.58% (101/380) in 2013, 2014, and 2015 respectively, 38.45% (198/515), 51.43% (18/35), 71.70% (38/53), and 17.96% (44/245) from Fujian Medical University Union Hospital, the 180th Hospital of PLA, the 92th Hospital of PLA, and Longyan First Hospital respectively, and 136/261, 8/137, 3/4, and 7/48 from wound exudate, blood, drainage fluid or tissue fluid, and the other specimens (including catheter tip attachments, sputum, feces) respectively. Among the 298 pathogens, 159 (53.36%) strains were gram-positive bacteria, 129 (43.29%) strains were gram-negative bacteria, and 10 (3.36%) strains were fungi. The detection rate of Staphylococcus aureus was the highest, totally 68 strains, accounting for 22.82%, followed by Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus epidermidis, with 37, 31, and 22 strains, accounting for 12.42%, 10.40%, and 7.38% respectively. Among Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA) accounted for 70.59% (48/68). Among Staphylococcus epidermidis, methicillin-resistant Staphylococcus epidermidis (MRSE) accounted for 68.18% (15/22). The resistant rates of MRSA and MRSE to penicillin and ampicillin were all 100.0%, and the resistant rates of MRSA to erythromycin, tetracycline, clindamycin and those of MRSE to erythromycin, cotrimoxazole were high. The high resistant rate of Pseudomonas aeruginosa towards antibiotics was detected with cotrimoxazole (83.3%) only. The resistant rates of Acinetobacter baumannii towards piperacillin, ceftazidime, and cotrimoxazole were high (from 58.8% to 71.4%). Conclusions: During the three years, there is large difference in the detection rate of pathogens from these four hospitals in Fujian province. The majority of pathogens were Gram-positive bacteria. The four dominant pathogens were Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus epidermidis. Most of the pathogens were resistant to antibiotics commonly used in clinic in different degree, especially MRSA, MRSE and Acinetobacter baumannii, which showed high resistance towards antibiotics.

[Qualitative study on the current status of hospitalized burn children's quality of life].

Objective: To explore the current status of hospitalized burn children's quality of life, so as to lay foundation for carrying out the related intervention in future. Methods: Using qualitative research method, semi-structured interviews were conducted on 11 parents of burn children hospitalized in Department of Burns of Fujian Medical University Union Hospital from March to May 2016. Then the data were analyzed and concluded with phenomenological analysis method to refine the themes. Results: Parents' description about the current status of hospitalized burn children's quality of life could be summed up into four areas: physiology, psychology, social development, and family; and in six themes: obvious itching symptom, limited movement development, night terror and constant cry because of fear, reduced social game, negative attachment type, and parents under multiple pressures. Conclusions: Burn brings serious harm to children's physical and mental development, as well as negative effects on the parents, thus lowering the children's quality of life. Medical workers should increase knowledge and attention of it, and carry out targeted health management project.

Diversity of endophytic bacteria in Caragana microphylla grown in the desert grassland of the Ningxia Hui autonomous region of China.

The diversity of endophytic bacteria in the sand-fixation plant Caragana microphylla was investigated by amplified rDNA restriction analysis and by sequence and phylogenetic comparisons of the 16S rRNA genes. A total of 24, 19, and 17 operational taxonomic units were identified from 16S rDNA libraries of the plant roots, stems and leaves, respectively. Homology analysis revealed a 92-100% identity of bacterial 16S rDNA sequences compared with those in the GenBank database. The bacteria identified by sequence homology fell into the following groups: α-Proteobacteria, ß-Proteobacteria, γ-Proteobacteria, bacilli, and uncultured bacterium. Sequence analysis demonstrated that the roots were colonized predominantly by Bradyrhizobiaceae, while bacteria from Burkholderiaceae and Sphingomonadaceae were predominant in the stems and leaves, respectively. Additionally, the endophytic bacterial community in leaves was more diverse than those in the roots and stems. Overall, the most abundant bacteria in all three tissues analyzed were from the Sphingomonadaceae and Burkholderiaceae families, although many bacterial populations were found in only a single tissue. These results suggest that the bacterial population of C. microphylla is diverse.

Effect of segmental artery ligation on the blood supply of the thoracic spinal cord during anterior spinal surgery: a quantitative histomorphological fresh cadaver study.

STUDY DESIGN: Human cadaver quantitative morphometric analysis of the blood vessels in the spinal cord after ligation of segmental arteries. OBJECTIVES: To investigate the effect of ligation of segmental arteries on the quantity and density of the blood vessels in the spinal cord. SUMMARY OF BACKGROUND DATA: Ligation of segmental arteries is often used in the anterior approach for correction scoliosis. However, whether or not segmental artery ligation is liable to deny the spinal cord an adequate blood supply, thus leading to paraplegia, still remains controversial. METHODS: Eleven fresh cadavers were divided into control, unilateral, and bilateral groups. For the unilateral and bilateral groups, 5 segmental vertebral arteries (T7-T11) were ligated unilaterally and bilaterally, respectively. Then, the number and density of blood vessels at different levels in the 3 groups were measured. RESULTS: Compared to that of the corresponding level in the control group, the number of blood vessels at T5 to L1 all decreased in the ligation groups. And significant differences were found at T8 (82.80 +/- 16.36), T10 (77.80 +/- 19.80), and T11 (99.20 +/- 14.85) levels, compared to those of the corresponding levels in the control group: T8 (175.80 +/- 8. 31), T9 (176.40 +/- 32. 33), T10 (171.40 +/- 9. 73), and T11 (189.20 +/- 15. 92). Further decrease was found at each corresponding level in the bilateral group, and significant differences were found at T8 (65.80 +/- 15.55), T9 (24.80 +/- 13.43), T10 (0), T11 (0), and T12 (0) levels. Similar results were obtained with regard to the density of blood vessels. Significant differences were found at T11 (1.246 +/- 0.112) and L1 (1.349 +/- 0.109) in the unilateral group, and T9 (0.260 +/- 0.088), T10 (0), T11 (0), T12 (0), and L1 (0.147 +/- 0.117) in the bilateral group compared to those of the corresponding levels in the control group: T9 (1.810 +/- 0.202), T10 (1.833 +/- 0.175), T11 (2.308 +/- 0.335), T12 (2.510 +/- 0.617), and L1 (2.193 +/- 0.033). CONCLUSIONS: This study suggests that the more levels the ligation encompasses, the higher the risk of spinal cord damage. Therefore, caution should be taken when several segmental arteries are to be ligated in the clinical setting. What is more, bilateral ligation, which is worse than unilateral ligation, can lead to a significant decrease in the number and density of blood vessels of the spinal.

Molecular scaffold of a new pokeweed antifungal peptide deduced by 1H nuclear magnetic resonance.

The antifungal peptide from seeds of Phytolacca americana (Pokeweed), designated PAFP-S hereinafter, is a recently found cationic peptide which consists of 38 amino acid residues and exhibits a broad spectrum of antifungal activity, including inhibition of certain saprophytic fungi and some plant pathogens. The secondary structure and three cysteine pairings have been investigated by 1H NMR analysis. The results show that the molecular scaffold of PAFP-S features a triple-stranded antiparallel beta-sheet knotted by a typical disulfide bridge motif, which characterizes the knottin fold. CD spectroscopy indicates a high stability of the molecule in solution. Therefore, PAFP-S should be a new member of the knottin structural family and the first antifungal peptide that adopts the knottin-like fold.

Solution structure of PAFP-S: a new knottin-type antifungal peptide from the seeds of Phytolacca americana.

The three-dimensional solution structure of PAFP-S, an antifungal peptide extracted from the seeds of Phytolacca americana, was determined using 1H NMR spectroscopy. This cationic peptide contains 38 amino acid residues. Its structure was determined from 302 distance restraints and 36 dihedral restraints derived from NOEs and coupling constants. The peptide has six cysteines involved in three disulfide bonds. The previously unassigned parings have now been determined from NMR data. The solution structure of PAFP-S is presented as a set of 20 structures using ab initio dynamic simulated annealing, with an average RMS deviation of 1.68 A for the backbone heavy atoms and 2.19 A for all heavy atoms, respectively. For the well-defined triple-stranded beta-sheet involving residues 8-10, 23-27, and 32-36, the corresponding values were 0.39 and 1.25 A. The global fold involves a cystine-knotted three-stranded antiparallel beta-sheet (residues 8-10, 23-27, 32-36), a flexible loop (residues 14-19), and four beta-reverse turns (residues 4-8, 11-14, 19-22, 28-32). This structure features all the characteristics of the knottin fold. It is the first structural model of an antifungal peptide that adopts a knottin-type structure. PAFP-S has an extended hydrophobic surface comprised of residues Tyr23, Phe25, Ile27, Tyr32, and Val34. The side chains of these residues are well-defined in the NMR structure. Several hydrophilic and positively charged residues (Arg9, Arg38, and Lys36) surround the hydrophobic surface, giving PAFP-S an amphiphilic character which would be the main structural basis of its biological function.

[Construction and expression of coexpression plasmid of carcinoembryonic antigen and Newcastle disease virus HN gene].

The eukaryotic expression plasmid (pcDNA3-CEA) containing with the gene coding for the Carcinoembryonic antigen(CEA) had been gotten with RT-PCR and gene recombination techniques. Using enzymolysis, ligation and other techniques, an eukaryotic coexpression plasmid(pcDNA3-CEA/HN) containing two expression unites of CEA and Newcastle disease virus HN gene that may have the function of immunoenhancement had been constructed. The plasmid will lay a foundation for further researching CEA nucleiotide vaccine, adjuvant and their effect of special antitumor immune.

[Cloning of Cysticercus cellulosae AgB cDNA coding region].

OBJECTIVE: To amplify and clone Cysticercus cellulosae AgB cDNA coding region. METHODS: The AgB cDNA was amplified by RT-PCR technique from the total RNA of Cysticercus cellulosae. It was cloned into the vector pUC118 and sequenced. RESULTS: The PCR amplified product was a single band of 2.6 kb in size. The sequences of AgB cDNA coding region has 99.8% homology with that of Australian Cysticercus cellulosae, and their amino acid sequences have 99.3% homology. CONCLUSION: Cysticercus cellulosae AgB cDNA coding region has been cloned successfully.

[The features of isozyme zymograms and genetic diversity in Undaria pinnatifida].

The zymogram features of 11 kinds of isozyme and gene expressions in Qingdao and Zhoushan population of U. pinnatifida gametophytes were investigated and genetic diversity was examined by PAGE (polyacrylamide gel electrophoresis) technique. The results showed that the level of genetic diversity in Qingdao population of U. pinnatifida gametophytes was higher than that in Zhoushan population. Two banding patterns controlled by two variant genes were found in alcohol dehydrogenase (Adh) of U. pinnatifida gametophytes. There were null alleles in the population.

Solution conformation of brazzein by 1H nuclear magnetic resonance: resonance assignment and secondary structure.

Brazzein is a sweet-tasting protein isolated from the fruit of the West African plant Pentadiplandra brazzeana Baillon. It is the smallest and the most water-soluble sweet protein discovered so far, it is also highly thermostable. The proton NMR study of brazzein at 600 MHz (pH 3.5, 300K) is presented. Complete sequence specific assignment of the individual backbone and sidechain proton resonances were achieved using through-bond and through-space connectivities obtained from standard two-dimensional NMR techniques. The secondary structure of brazzein contains one alpha-helix (residues 21-29), one short 3(10)-helix (residues 14-17), two strands of antiparallel beta-sheet (residues 34-39, 44-50) and probably a third strand (residues 5-7) near the N-terminus.

The role of endothelin-1 in Binswanger's disease.

BACKGROUND: Endothelin-1 is known to exist in the nervous system. A notable increase of plasma endothelin-1 is associated with acute stroke. This study was designed to measure plasma endothelin-1 levels in Binswanger's disease and explore the relationship between endothelin-1 and this disorder. METHODS: Plasma levels of endothelin-1 were-examined by radioimmunoassay in 31 patients with Binswanger's disease and in three groups of control subjects. The ratio of the plasma concentration of endothelin-1 in the internal jugular vein to that in the antecubital vein was calculated as an indicator of endothelin-1 level in cerebral circulation. RESULTS: Endothelin-1 ratio devation was seen more often in patients with Binswanger's disease than in acute stroke patients. Endithelin-1 ratios were significantly negatively correlated with Hasegawa's Dementia Scale scores is subjects with Binswanger's disease. CONCLUSIONS: Abnormalities is vasoactive factors may make an important contribution to the pathophysiology of Binswanger's disease. Endothelin-1 might be involved in the pathogenesis of this illness.