Evaluating the Performance of UV Disinfection across the 222-365 nm Spectrum against Aerosolized Bacteria and Viruses

Bioaerosols play a significant role in the transmission of many infectious diseases, especially in enclosed indoor environments. Ultraviolet (UV) disinfection has demonstrated a high efficacy in inactivating microorganisms suspended in the air. To develop more effective and efficient UV disinfection protocols, it is necessary to evaluate and optimize the effectiveness of UV disinfection against aerosolized bacteria and viruses across the entire UV spectrum. In this study, we evaluated the performance of UV disinfection across the UV spectrum, ranging from 222 to 365 nm, against aerosolized bacteria and viruses, including Escherichia coli, Staphylococcus epidermidis, Salmonella enterica, MS2, P22, and Phi6. Six commonly available UV sources, including gas discharge tubes and light-emitting diodes with different emission spectra, were utilized, and their performance in terms of inactivation efficacy, action spectrum, and energy efficiency was determined. Among these UV sources, the krypton chloride excilamp emitting at a peak wavelength of 222 nm was the most efficient in inactivating viral bioaerosols. A low-pressure mercury lamp emitting at 254 nm performed well on both inactivation efficacy and energy efficiency. A UV light-emitting diode emitting at 268 nm demonstrated the highest bacterial inactivation efficacy, but required approximately 10 times more energy to achieve an equivalent inactivation level compared with that of the krypton chloride excilamp and low-pressure mercury lamp. This study provides insights into UV inactivation on bioaerosols, which can guide the development of effective wavelength-targeted UV air disinfection technologies and may significantly help reduce bioaerosol transmission in public areas.

[Research and exploration of salivary biological markers for hepatitis B-related hepatocellular carcinoma]

Objective: To study using isotope-labeled relative and absolute quantitative proteomics methodologies to screen for salivary biological markers as a simple, non-invasive tool for identifying hepatitis B-related HCC at an early stage. Methods: Saliva samples were collected to extract salivary proteins. Isotope-labeled relative and absolute quantitative proteomics were used to analyze the differentially expressed proteins between the hepatocellular carcinoma (HCC) and non-HCC groups. Western blotting, immunohistochemistry, and enzyme-linked immunosorbent assays were used to verify differential proteins and identify markers in liver cancer tissues and saliva. Statistical analysis was used to analyze the diagnostic efficiency of salivary biomarkers. Results: 152 differentially expressed salivary proteins were screened out between the HCC and non-HCC groups. Western blot, immunohistochemistry, and enzyme-linked immunosorbent assays validated that the expressions of α-1-acid glycoprotein 1 (ORM1) and alpha-fetoprotein (AFP) were significantly increased in HCC (P < 0.05). There was a significant correlation between salivary AFP and serum AFP (P < 0.05). HCC was diagnosed when salivary α-1-acid glycoprotein 1 combined with AFP. The area under the receiver operating characteristic curve was 0.8726 (95% confidence interval: 0.8104 ~ 0.9347), the sensitivity was 78.3%, and the specificity was 88%. Conclusion: Salivary AFP and α-1-acid glycoprotein 1 can serve as potential biomarkers for hepatitis B-related hepatocellular carcinoma.

Synergistic disinfection of aerosolized bacteria and bacteriophage by far-UVC (222-nm) and negative air ions

Air ionizers and 222-nm krypton-chlorine (KrCl) excilamp have proven to be effective disinfection apparatus for bacteria and viruses with limited health risks. We determined inactivation efficiencies by operating them individually and in combined modules. Gram-positive and gram-negative bacteria, non-enveloped dsDNA virus, and enveloped dsRNA virus were examined in a designed air disinfection system. Our results showed that the bioaerosols were inactivated efficiently by negative ionizers and far-UVC (222-nm), either used individually or in combination. Among which the combined modules of negative ionizers and KrCl excilamp had the best disinfection performance for the bacteria. The aerosolized virus P22 and Phi 6 were more susceptible to 222-nm emitted by KrCl excilamp than negative air ions. Significant greater inactivation of bacterial bioaerosols were identified after treated by combined treatment of negative air ion and far-UVC for 2 minutes (Escherichia coli, 6.25 natural log (ln) reduction; Staphylococcus epidermidis, 3.66 ln reduction), as compared to the mean sum value of inactivation results by respective individual treatment of negative ionizers and KrCl excilamp (Escherichia coli, 4.34 ln; Staphylococcus epidermidis, 1.75 ln), indicating a synergistic inactivation effect. The findings provide important baseline data to support the design and development of safe and high-efficient disinfection systems.

[Analysis on vaccination willingness and related factors of influenza, pneumonia, and herpes zoster vaccine among people over 50 years old in Minhang district of Shanghai]

Objective: To determine the knowledge of influenza, pneumonia, herpes zoster and related vaccines, willingness to vaccinate under multiple payment scenarios, and corresponding risk factors among people over 50 years old in Minhang District of Shanghai. Methods: A total of 1 672 respondents aged 50-69 from 13 communities/towns in Minhang district of Shanghai were included in this study using a stratified random sampling strategy on December 2020. The knowledge of influenza, pneumonia, herpes zoster and vaccines was investigated using a questionnaire, and the differences in the willingness under multiple payment scenarios were determined using chi-square test. The consistency in the willingness under multiple payment scenarios was compared using Cohen's Kappa and the risk factors of the willingness was determined using ordinal logistic regression. Results: The average age of 1 672 respondents was (60.48±5.96) years old, including 777 (46.47%) males and 895 (53.53%) females. A total of 1 350 subjects (80.74%) had local household registration in Shanghai. The proportion of the willingness to vaccinate for themselves, spouses, and parents under any payment scenario was determined to be 80.6% (influenza vaccine), 81.5% (pneumonia vaccine), and 74.0% (herpes zoster vaccine). The willingness to vaccinate against influenza and pneumonia under multiple payment scenarios remained stable (Kappa value ≥0.6), while that against herpes zoster infection was inconsistent (Kappa value ≤0.35). Logistic regression analysis showed that respondents who had higher knowledge of influenza and influenza vaccine [OR (95%CI): 1.111 (1.054-1.170), 1.182 (1.126-1.240), respectively], aged 50-59 [1.305 (1.085-1.531)] and local household registration in Shanghai [1.372 (1.079-1.721)] had higher willingness to vaccinate against influenza, while males had lower willingness [0.733 (0.551-0.910)]. Respondents who had higher knowledge of pneumonia and pneumonia vaccine [OR (95%CI): 1.837 (1.152-2.517), 2.217 (1.541-2.893), respectively] had higher willingness to receive pneumonia vaccine. Respondents aged 50-59 [1.327 (1.059-1.537)] and with local household registration in Shanghai [2.497 (1.417-4.400)] were more likely to be vaccinated against herpes zoster, while those with middle school degree or below [0.664 (0.396-0.992)] and high school degree [0.559 (0.324-0.964)] were less likely to be vaccinated. Conclusion: Among people aged over 50 years old in Minhang district of Shanghai, the willingness to vaccinate for themselves, spouses, and parents against influenza, pneumonia and herpes zoster infection is quite different under multiple payment scenarios, especially for herpes zoster vaccine.

Evolutionary Analysis of the YABBY Gene Family in Brassicaceae

The YABBY gene family is one of the plant transcription factors present in all seed plants. The family members were extensively studied in various plants and shown to play important roles in plant growth and development, such as the polarity establishment in lateral organs, the formation and development of leaves and flowers, and the response to internal plant hormone and external environmental stress signals. In this study, a total of 364 YABBY genes were identified from 37 Brassicaceae genomes, of which 15 were incomplete due to sequence gaps, and nine were imperfect (missing C2C2 zinc-finger or YABBY domain) due to sequence mutations. Phylogenetic analyses resolved these YABBY genes into six compact clades except for a YAB3-like gene identified in Aethionema arabicum. Seventeen Brassicaceae species each contained a complete set of six basic YABBY genes (i.e., 1 FIL, 1 YAB2, 1 YAB3, 1 YAB5, 1 INO and 1 CRC), while 20 others each contained a variable number of YABBY genes (5-25) caused mainly by whole-genome duplication/triplication followed by gene losses, and occasionally by tandem duplications. The fate of duplicate YABBY genes changed considerably according to plant species, as well as to YABBY gene type. These YABBY genes were shown to be syntenically conserved across most of the Brassicaceae species, but their functions might be considerably diverged between species, as well as between paralogous copies, as demonstrated by the promoter and expression analysis of YABBY genes in two Brassica species (B. rapa and B. oleracea). Our study provides valuable insights for understanding the evolutionary story of YABBY genes in Brassicaceae and for further functional characterization of each YABBY gene across the Brassicaceae species.

[A comparative study on the difference of gut microbiota and its biomarkers between patients with pulmonary tuberculosis and healthy controls]

Objective: To analyze the differences in the composition and abundance of gut microbiota between patients with active pulmonary tuberculosis and healthy controls, and to identify the specific bacteria as biomarkers to distinguish between the two groups. Methods: Patients with active pulmonary tuberculosis treated in three municipal designated tuberculosis medical institutions in Sichuan, Jiangsu and Shanghai from September 2017 to September 2019 were selected as the case group (n=88), and the healthy people without a history of tuberculosis from the same regions were recruited as the control group (n=62). The fecal samples of the two groups were detected by 16S rRNA gene sequencing, and the differences of gut microbiota diversity, community composition and relative abundance at phylum and genus level from the two groups were analyzed. The random forest method was used to construct a predictive model to assess whether the specific bacterial flora could be used as biomarkers to distinguish tuberculosis patients from healthy people. Results: The alpha diversity analysis showed that the species richness and evenness of gut microbiota in tuberculosis patients were significantly lower than those in healthy controls (P<0.001). There was a statistically significant difference in the composition of microbiota between the two groups (Bray-Curtis distance, P<0.001). In the gut microbiota of tuberculosis patients, opportunistic pathogens were relatively enriched, while some of the beneficial bacteria that can produce short-chain fatty acids were less abundant. The discrimination accuracy of the random forest model composed of Lachnospira, Lachnospiraceae ND3007 group and Roseburia was 76.67%, with area under the curve (AUC) being 75.29% (95%CI: 0.661-0.845). Conclusion: There were differences in gut microbiota between patients with active pulmonary tuberculosis and healthy people, and specific bacterial flora showed the potential to be used as biomarkers to distinguish between the two groups.

[A novel compound heterozygous mutation in MYSM1 gene in a 1-month-old girl: a bone marrow failure syndrome 4 family survey and literature review]

目的

报道1例MYSM1基因复合杂合变异致骨髓衰竭综合征4型患儿临床表现及全外显子检测结果，同时报道其家系全外显子检测结果，为早期诊断此类骨髓衰竭综合征提供典型案例。

方法

报道1例1月龄骨髓衰竭综合征4型患儿临床诊断过程，并对患儿及其家系成员外周血DNA进行全外显子测序，使用BWA、GATK等软件对测序结果进行注释分析。

结果

本例1月龄骨髓衰竭综合征4型患儿，表现为全血细胞减少、多指畸形，影像学示非特异性脑白质改变及囊肿，淋巴细胞亚群分类示CD3⁻CD19⁺ B细胞降低。通过家系全外显子测序检测，鉴定患儿携带分别遗传自父母的MYSM1基因复合杂合性变异NM_001085487.2:c.1607_c.1611delAAGAG和c.1432C>T。家系验证证实先证者父亲携带的c.1432C>T突变来源于先证者祖父，先证者母亲携带的c.1607_c.1611delAAGAG突变来自于先证者外祖父，其他家系成员均不携带突变。

结论

本研究新发现MYSM1致病性变异c.1607_c.1611delAAGAG，国内外尚未见报道。本例为BMFS4的早期诊断提供了典型案例，并扩展了MYSM1基因致病性变异谱和表型谱。

[Epidemiological study design of asymptomatic infection of the 2019 novel coronavirus]

COVID-19 is caused by the 2019 novel coronavirus (2019-nCoV). COVID-19 clinical cases are considered as the principal source of infection, however, asymptomatic cases may also play a role in the transmission. Significant gap exists in terms of the proportion or prevalence and transmissibility of asymptomatic cases. This study design plans to use data from areas with different epidemiological profiles to investigate the COVID-19 epidemic in China. In each selected region, both general community residents and key populations at high risk of COVID-19 infection, including recovered COVID-19 cases, close contacts of confirmed COVID-19 cases, medical professionals, investigators at CDCs, and visitors to fever clinics, will be recruited and examined for viral RNA of 2019-nCoV and serum antibodies. Prevalence and characterization of asymptomatic cases will be determined, stratified by varied demographics and exposure risk. During the follow-up, the change in the serum antibodies will be studied prospectively in the symptomatic and asymptomatic cases to address the scientific and public health concerns of infectivity and transmissibility of 2019-nCoV.

[Value of ultrasound-targeted vascular endothelial growth factor receptor-2 in non-invasive monitoring of anti-angiogenic response in nude mice with subcutaneous xenograft model]

Objective: To investigate the value of contrast-enhanced ultrasound targeting vascular endothelial growth factor receptor-2 (VEGFR-2) in non-invasive monitoring of anti-angiogenesis response in subcutaneous transplantation tumor model of hepatocellular carcinoma in nude mice. Methods: Sixteen nude mice were randomly divided into control group and bevacizumab treatment group (treatment group). Two weeks later, the model of subcutaneous transplanted tumor was established. The mice in the treatment group were intratumorally injected with 0.2 mg bevacizumab, while the control group was given the same amount of saline, three times a week for 2 weeks. Ultrasound microbubbles targeting VEGFR-2 were prepared by biotin avidin method. Ultrasound examinations were performed before treatment, 7 days and 14 days after treatment, and the time intensity curve (TIC) was drawn to quantitatively analyze the differences of parameters with treatment time. The expression of CD31 in tumor tissues was detected by immunohistochemistry. Results: After 14 days of treatment, the volume of tumor tissue in the treatment group and the control group were (0.247±0.019) mm(3) and (0.307±0.031) mm(3,) respectively, the difference was statistically significant (P<0.01). After 7 days of treatment, the rise slope (K(1)), time to peak (TTP) and peak intensity (PI) of TIC curve in the treatment group were 3.77±0.62, (3.82±0.21) s and (24.35±3.34) dB, respectively, which were significantly different from 2.93±0.31, (4.47±0.50) s and (30.10±2.35) dB in the control group, respectively (P<0.05). Immunohistochemistry showed that the PI of contrast enhanced ultrasound was positively correlated with microvessel density (r(2)=0.898, P=0.017). Conclusions: The therapeutic effect of bevacizumab on tumor angiogenesis evaluated by contrast-enhanced ultrasound targeting VEGFR-2 is related to the differences of parameters such as K(1), TTP and PI of TIC index. Contrast enhanced ultrasound targeting VEGFR-2 is of great value in non-invasive monitoring of subcutaneous transplanted tumor model of hepatocellular carcinoma in nude mice.

[Expanding the pandemic influenza preparedness framework to the epidemic of COVID-19]

On March 11, 2020, WHO officially declared that COVID-19 had become Pandemic. As of March 31, the epidemic had affected more than 178 countries and regions, with more than 780 000 confirmed cases. The Pandemic Influenza Preparedness Framework for the sharing of influenza viruses and access to vaccines and other benefits (the 'PIP Framework' or 'Framework') is an international arrangement adopted by the World Health Organization in May 2011 to improve global pandemic influenza preparedness and response. Since the transmission route and transmission capacity of COVID-19 are similar to that of influenza A (H1N1) in 2009, which conforms to the basic elements of "human pandemic", and the epidemic scale has exceeded that of influenza A (H1N1)， it is probable to incorporate COVID-19 epidemic response into PIPF, and at the same time to verify and improve PIPF in practice. It is recommended that WHO, other international organizations and relevant countries make full use of the PIPF system to respond to the epidemic and better coordinate national actions at the global level. At the same time, China should also make the planning and deploy of domestic epidemic prevention and control and international epidemic cooperation under the framework.

[Epidemiological analysis on bud-events of Norovirus-associated infectious diarrhea in Shanghai, 2018]

Objective: To analyze the epidemiological characteristics related to Norovirus-associated infectious diarrhea bud events in Shanghai, and to discuss the value of bud events surveillance, so as to help Norovirus-associated infectious diarrhea control, prevention and to improve the surveillance system on bud events. Methods: Data related to 142 Norovirus-associated infectious diarrhea bud events were gathered from 16 districts of Shanghai areas in 2018 and were analyzed. Results: There were 2 peaks, April and November for 142 Norovirus-associated infectious diarrhea bud events reported in 2018. 98.59% (140/142) of the bud events occurred in schools and kindergartens. 80.28% (114/142) of the bud events would involve 6-19 cases per each event. The median time duration between the onset date of the first case and the reporting date of the event was 2 days and the median event duration was 7 days. The bud event scale and regional incidence of bud events as well as the reporting timelines were influential factors on the duration of the bud events. Conclusions: Two peaks, spring and winter bud events of the Norovirus-associated infectious diarrhea were seen in Shanghai in 2018. Schools and kindergartens were to be prioritized locations for control and prevention of Norovirus-associated infectious diarrhea bud events. Surveillance system was proved to have contributed to the early detection, reporting and control of bud events.

[Advances in the research of pain assessment and non-drug intervention in burn children]

Children are a high-risk group of burn, and burn pain is a special type of pain. Because children of different ages have different cognitive ability and behavioral response to pain, thus it is particularly difficult to effectively evaluate the pain. It is very important for medical staff to understand the pain of children, to define the adverse reactions of pain, to evaluate and take appropriate pain intervention measures in time and effectively. In this paper, different evaluation methods of burn pain in children and non-drug intervention related measures were reviewed in order to provide references for clinical practice.

Genome wide survey, evolution and expression analysis of PHD finger genes reveal their diverse roles during the development and abiotic stress responses in Brassica rapa L

BACKGROUND

Plant homeodomain (PHD) finger proteins are widely present in all eukaryotes and play important roles in chromatin remodeling and transcriptional regulation. The PHD finger can specifically bind a number of histone modifications as an "epigenome reader", and mediate the activation or repression of underlying genes. Many PHD finger genes have been characterized in animals, but only few studies were conducted on plant PHD finger genes to this day. Brassica rapa (AA, 2n = 20) is an economically important vegetal, oilseed and fodder crop, and also a good model crop for functional and evolutionary studies of important gene families among Brassica species due to its close relationship to Arabidopsis thaliana.

RESULTS

We identified a total of 145 putative PHD finger proteins containing 233 PHD domains from the current version of B. rapa genome database. Gene ontology analysis showed that 67.7% of them were predicted to be located in nucleus, and 91.3% were predicted to be involved in protein binding activity. Phylogenetic, gene structure, and additional domain analyses clustered them into different groups and subgroups, reflecting their diverse functional roles during plant growth and development. Chromosomal location analysis showed that they were unevenly distributed on the 10 B. rapa chromosomes. Expression analysis from RNA-Seq data showed that 55.7% of them were constitutively expressed in all the tested tissues or organs with relatively higher expression levels reflecting their important housekeeping roles in plant growth and development, while several other members were identified as preferentially expressed in specific tissues or organs. Expression analysis of a subset of 18 B. rapa PHD finger genes under drought and salt stresses showed that all these tested members were responsive to the two abiotic stress treatments.

CONCLUSIONS

Our results reveal that the PHD finger genes play diverse roles in plant growth and development, and can serve as a source of candidate genes for genetic engineering and improvement of Brassica crops against abiotic stresses. This study provides valuable information and lays the foundation for further functional determination of PHD finger genes across the Brassica species.

Comprehensive Genomic Survey, Characterization and Expression Analysis of the HECT Gene Family in Brassica rapa L. and Brassica oleracea L

The HECT-domain protein family is one of the most important classes of E3 ligases. While the roles of this family in human diseases have been intensively studied, the information for plant HECTs is limited. In the present study, we performed the identification of HECT genes in Brassica rapa and Brassica oleracea, followed by analysis of phylogeny, gene structure, additional domains, putative cis-regulatory elements, chromosomal location, synteny, and expression. Ten and 13 HECT genes were respectively identified in B. rapa and B. oleracea and then resolved into seven groups along with their Arabidopsis orthologs by phylogenetic analysis. This classification is well supported by analyses of gene structure, motif composition within the HECT domain and additional protein domains. Ka/Ks ratio analysis showed that these HECT genes primarily underwent purifying selection with varied selection pressures resulting in different rates of evolution. RNA-Seq data analysis showed that the overwhelming majority of them were constitutively expressed in all tested tissues. qRT-PCR based expression analysis of the 10 B. rapa HECT genes under salt and drought stress conditions showed that all of them were responsive to the two stress treatments, which was consistent with their promoter sequence analysis revealing the presence of an important number of phytohormone-responsive and stress-related cis-regulatory elements. Our study provides useful information and lays the foundation for further functional determination of each HECT gene across the Brassica species.

[Evaluation of the right ventricular function in patients with pneumoconiosis by echocardiography]

Objective: To investigate right ventricular function in patients with pneumoconiosis, and to provide a basis for quantitative diagnosis and treatment of pneumoconiosis in clinical practice. Methods: A total of 43 patients with pneumoconiosis who were hospitalized consecutively in Shijiazhuang Prevention and Treatment Center for Occupational Diseases from May 2015 to May 2016 were enrolled, and according to the stage of pneumoconiosis, they were divided into stage I group with 16 patients, stage II group with 14 patients, and stage III group with 13 patients. A total of 16 healthy subjects were enrolled as control group. Echocardiography was performed and the relevant parameters were recorded, i.e., right ventricular transverse diameter (RVTD), tricuspid annular plane systolic excursion (TAPSE), and right ventricular myocardial performance index(Tei index). Results: There were significant differences in Tei index and TAPSE between all groups (P <0.05) except between the stage I group and the control group in terms of Tei index (P>0.05) and between the stage I group and the stage II group in terms of TAPSE (P>0.05). Right ventricular Tei index was negatively correlated with TAPSE (r=-0.547,P<0.05). Conclusion: A combination of right ventricular Tei index and TAPSE can be used for early quantitative evaluation of right ventricular function in patients with pneumoconiosis.

Genome-wide survey, characterization, and expression analysis of RING finger protein genes in Brassica oleracea and their syntenic comparison to Brassica rapa and Arabidopsis thaliana

The ubiquitin-mediated post-translational regulatory pathway regulates a broad range of cell functions in all eukaryotes. It requires the involvement of a large number of E3 ligases, of which more than one third belongs to the RING protein family as in Arabidopsis thaliana. In this study, a total of 756 RING domains in 734 predicted proteins were identified in Brassica oleracea. Their encoding genes were characterized by RING domain type, additional domain, and expression pattern, and mapped on the nine chromosomes of B. oleracea. Comparison of these results with B. rapa and A. thaliana revealed some common as well as species-specific features. Our results showed that the differential gene loss following the whole genome triplication has largely contributed to the RING protein gene number variation among these species, although other factors such as tandem duplication, RING domain loss, or modification had also contributed to this variation. Analysis of RNA-seq data showed that these RING protein genes were functionally diversified and involved in all the stages of plant growth and development, and that the triplicated members were also diverged in expression with one member often more dominantly expressed over the two others in the majority of cases. Our study lays the foundation for further functional determination of each RING protein gene among species of the genus Brassica.

[Spatial-temporal distribution characteristics of hepatitis E in Shanghai, 2006-2016]

Objective: To understand the epidemiologic characteristics and spatial-temporal distribution of hepatitis E in Shanghai between 2006 and 2016. Methods: The reported incidence of hepatitis E and health facilities' information between 2006 and 2016 were collected from the China Information System for Disease Control and Prevention. The geographic information were from Shanghai Surveying and Mapping Institute. The map scale was 1∶750 000. Global and local autocorrelation, and spatial-temporal detection methods were applied to determine the spatial-temporal characteristics of hepatitis E. Software ArcGIS 10.1 was used to analyze global and local spatial auto correlation of hepatitis E spatial clusters. Software SaTScan 9.4.4 was used to conduct scan for exploring the areas of hepatitis E temporal spatial clusters. Results: A total of 6 048 cases of hepatitis E were reported in Shanghai during 2006-2016. The average incidence was 2.14/100 000. Spatial auto correlation analysis indicated that there was significant spatial positive correlations and spatial-temporal clustering of hepatitis E in Shanghai, and the "high-high cluster" was mainly located in the downtown of the city. Conclusion: Understanding the spatial-temporal clustering areas of hepatitis E cases in Shanghai from 2006 to 2016 is important to the reasonable allocation of public health resources and effective prevention and control of hepatitis E.

Charge Transfer Effects in Naturally Occurring van der Waals Heterostructures (PbSe)_{1.16}(TiSe_{2})_{m} (m=1, 2)

van der Waals heterostructures (VDWHs) exhibit rich properties and thus has potential for applications, and charge transfer between different layers in a heterostructure often dominates its properties and device performance. It is thus critical to reveal and understand the charge transfer effects in VDWHs, for which electronic structure measurements have proven to be effective. Using angle-resolved photoemission spectroscopy, we studied the electronic structures of (PbSe)_{1.16}(TiSe_{2})_{m} (m=1, 2), which are naturally occurring VDWHs, and discovered several striking charge transfer effects. When the thickness of the TiSe_{2} layers is halved from m=2 to m=1, the amount of charge transferred increases unexpectedly by more than 250%. This is accompanied by a dramatic drop in the electron-phonon interaction strength far beyond the prediction by first-principles calculations and, consequently, superconductivity only exists in the m=2 compound with strong electron-phonon interaction, albeit with lower carrier density. Furthermore, we found that the amount of charge transferred in both compounds is nearly halved when warmed from below 10 K to room temperature, due to the different thermal expansion coefficients of the constituent layers of these misfit compounds. These unprecedentedly large charge transfer effects might widely exist in VDWHs composed of metal-semiconductor contacts; thus, our results provide important insights for further understanding and applications of VDWHs.

Molecular insights into the origin of the brown rust resistance gene Bru1 among Saccharum species

Analysis of 387 sugarcane clones using Bru 1 diagnostic markers revealed two possible sources of Bru 1 in Chinese cultivars: one from Saccharum spontaneum and another from Saccharum robustum of New Guinea. Sugarcane brown rust (SBR) is an important fungal disease in many sugarcane production areas around the world, and can cause considerable yield losses in susceptible sugarcane cultivars. One major SBR resistance gene, named Bru1, initially identified from cultivar R570, was shown to be a major SBR resistance source in most of the sugarcane producing areas of the world. In this study, by using the two Bru1-associated markers, R12H16 and 9O20-F4, we surveyed the presence of Bru1 in a Chinese sugarcane germplasm collection of 387 clones, consisting of 228 hybrid cultivars bred by different Chinese sugarcane breeding establishments, 54 exotic hybrid cultivars introduced from other countries and 105 clones of sugarcane ancestral species. The Bru1-bearing haplotype was detected in 43.4% of Chinese sugarcane cultivars, 20.4% of exotic hybrid cultivars, and only 3.8% of ancestral species. Among the 33 Chinese cultivars for which phenotypes of resistance to SBR were available, Bru1 was present in 69.2% (18/26) of the resistant clones. Analyses of the allelic sequence variations of R12H16 and 9O20-F4 suggested two possible sources of Bru1 in Chinese cultivars: one from S. spontaneum and another from S. robustum of New Guinea. In addition, we developed an improved Bru1 diagnostic marker, 9O20-F4-HaeIII, which can eliminate all the false results of 9O20-F4-RsaI observed among S. spontaneum, as well as a new dominant Bru1 diagnostic marker, R12E03-2, from the BAC ShCIR12E03. Our results provide valuable information for further efforts of breeding SBR-resistant varieties, searching new SBR resistance sources and cloning of Bru1 in sugarcane.

[Evolutionary characteristics and positive selection site of hepatitis C virus isolated in intravenous drug users in Pudong new district, Shanghai]

Objective: To understand the genotypes of hepatitis C virus (HCV) circulating in intravenous drug users (IDUs) in Pudong new district, Shanghai, and explore the population growth and selection pressure of the HCV strains isolated. Methods: A total of 200 serum specimens sampled from IDUs in local methadone maintenance treatment clinic in Pudong were used for amplification of a HCV NS5B 377-nt partial sequence. Mean evolutionary rate and effective number of infections were estimated based on the 377-nt partial sequences of the HCV strains isolated from IDUs and isolated contemporarily from local voluntary blood donors, men who have sex with men and reported hepatitis C cases by using BEAST software. Selection pressure sites were identified with online Datamonkey software for subsequent comparison with direct-acting antiviral (DAA) drug binding sites. Results: A total of 39 (19.5%) serum specimens were positive for HCV RNA. The genotypes were determined based on the HCV NS5B 377-nt partial sequences as follows: subtype 3a (n=14), 3b (n=13), 1b (n=7), 6a (n=4) and 6n (n=1). The partial sequences of the HCV strains isolated in IDUs shared high homology with the sequences of the HCV strains isolated in other populations. The Bayesian Skyline Plot indicated that the estimated infections with HCV subtype 1b increased exponentially during the 1990s, whereas that of subtypes 3a and 3b increased slowly since the mid-1990s. In the NS5B 377-nt partial sequences of the HCV strains isolated in IDUs, there were two positive selection sites and seventy-eight negative selection sites recognized. The mutation rate was as low as 2.2% in the 377-nt partial sequences corresponding to the known seven DAA drug binding sites. Conclusions: HCV subtype 3a and 3b were the predominant genotypes in the IDUs in Pudong. Subtype 1b was prevalent in different populations and evolved very rapidly, and more infections might be caused, suggesting further attention to its prevention, control and treatment. Although DAA treatment based on HCV NS5B binding sites targeting local IDUs might be effective, it is still necessary to strengthen the surveillance.

[Application of " Internet Plus" AIDS prevention services among men who have sex with men in Guangzhou, China: results from 2010 to 2015]

Objective: To introduce the development strategy of " Internet Plus" AIDS prevention services and its implementation results from 2010 to 2015 in Guangzhou, China. Methods: A gay men's health column was created for an active website aimed at men who have sex with men(MSM), in collaboration with local community organizations and the Guangzhou CDC. We designed intervention tools(including scenario-based applications and HIV risk self-assessment systems)and an online HIV testing service platform, integrated with applied psychology and behavioral theory as well as the " Internet Plus" concept, to intervene in HIV infection risk factors among MSM. Data of clients who accessed the " Internet Plus" AIDS services from 2010 to 2015 were used to evaluate service operation. Six-year consecutive surveys, conducted between April and July of each service year, were collected using a national AIDS sentinel surveillance questionnaire. For each year of surveillance, information on HIV prevalence, HIV interventions received during the past year, unprotected anal intercourse in the past 6 months, and HIV testing in the past year were compared using the chi-squared(χ²)test, to roughly reflect the effect of"Internet Plus" AIDS prevention services. Results: As of 31 December 2015, a total of 34 395 MSM had received " Internet Plus" services and HIV testing. The number of MSM tested increased from 2 338 in 2010 to 8 054 in 2015. From 2010 to 2015, newly identified HIV cases in each year were 59, 166, 312, 283, 291, and 270, which accounted for 25.0%, 32.8%, 38.8%, 35.1%, 30.5%, and 23.2% of MSM HIV cases of Guangzhou, respectively. Sentinel surveillance data showed that during the study period, 3 047 MSM were investigated, with 405, 400, 401, 633, 608, and 600 each year, respectively. The proportion of participants who had received any HIV intervention during the past year was 74.3%(301), 70.8%(283), 83.3%(334), 85.0%(538), 69.1%(420), and 83.8%(503)each year, respectively(trend χ²=6.53, P=0.011). HIV testing done during the past year accounted for 44.0%(178), 44.3%(177), 49.4%(198), 53.4%(338), 56.1%(341), and 60.2%(361)each year, respectively(trend χ²=40.83, P<0.001). Unprotected anal intercourse in the past 6 months accounted for 59.3%(240), 62.0%(248), 56.6%(227), 57.0%(361), 48.4%(294), and 43.7%(262)each year, respectively(trend χ²=42.21, P<0.001). Conclusion: The"Internet Plus"AIDS prevention services in this study represent a manner to enhance traditional HIV prevention strategies. We found these services to be effective in implementation of the national AIDS control and prevention strategy, especially for the expansion of intervention, testing, and case identification among high-risk populations.

Reproductive Cost Associated With Juvenile Hormone in Bt-Resistant Strains of Helicoverpa armigera (Lepidoptera: Noctuidae)

Transgenic Bacillus thuringiensis (Bt) crops are increasingly significant in pest control, but resistance development of target pests is a major issue in the sustainable deployment of Bt crops. The fitness cost of resistance in target pests is regarded as one of the main factors delaying resistance when adopting the refuge strategy. In this study, we compared the life-history traits of three independent sets of Helicoverpa armigera (Hübner, 1809) adults, of each there were a susceptible population and a Cry1Ac-resistant population derived by selection from it. Confirming to the previous studies, resistant individuals exhibited fewer progeny, less fecundity, lower egg hatching rate, and longer adult longevity. And poor fecundity in resistant strains was associated with the decline of the mature follicular amount, the ovarian weight ratio, and the length of the longest ovarian tubule. Interestingly, the juvenile hormone (JH) level appeared higher in resistant strains relative to susceptible strains. Application of methoprene (JH analogue) in vivo was effective in reducing fecundity and hatchability with the up-regulation of detected JH titer. These results suggested that resistance against Bt toxin reduced the reproductive capacity of H. armigera, and JH level is affected in the tradeoff between reproductive capacity and Bt resistance.

[A survey of correlation between serum 25-hydroxyvitamin D levels and dyslipidemia rlsk among middle-aged individuals in Beijing]

OBJECTIVE

To evaluate vitamin D status in middle-aged subjects in Beijing and explore the correlation between serum 25-hydroxyvitamin D[25(OH)D] levels and dyslipidemia.

METHODS

A total of 448 individuals over 40 years old were enrolled in the cross-sectional survey. The general information, blood biochemical and lipid profiles and serum 25(OH)D levels were collected. The subjects were either divided into two groups (the dyslipidemia group and the non-dyslipidemia group) based on the lipid levels, or four groups according to quartiles of 25(OH)D levels. The association between 25(OH)D levels and dyslipidemia risk was analyzed by a logistic regression analysis.

RESULTS

A total of 234 cases were in dyslipidemia group, which accounted for 52.23% of the subjects. The serum 25(OH)D levels were significantly lower in the dyslipidemia group than in the non-dyslipidemia group both in men and in women (all P<0.05). The median serum 25(OH)D level in the total subjects was 15.7 (12.2, 20.1)μg/L with 91.1% subjects of serum 25(OH)D level<30 μg/L. The proportion of subjects with dyslipidemia (high TC, high TG, high LDL-C, or low HDL-C) increased with the decrease of 25(OH)D level quartiles (P<0.05). After adjustment of confounding factors, the logistic regression analysis showed that subjects in the lowest 25(OH) D quartile group had 143% higher risks for dyslipidemia than those in the highest quartile group.

CONCLUSION

These findings indicate that 25(OH)D insufficiency is highly prevalent among middle-aged individuals and it may be associated with the risk of dyslipidemia.

In VitroandIn VivoReversal of Cancer Cell Multidrug Resistance by 2',4'-Dihydroxy-6'-methoxy-3',5'- dimethylchalcone

2',4'-Dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC) isolated from the buds of Cleistocalyx operculatus, was investigated for its reversal effects on cancer cell multidrug resistance. DMC potentiated the cytotoxicity of the chemotherapeutic agent doxorubicin to drug-resistant KB-A1 cells. When 5 microM DMC was present simultaneously with doxorubicin, the IC50 of DOX on KB-A1 cells decreased from 13.9 +/- 0.7 microg/ml to 3.6 +/- 0.7 microg/ml. A human carcinoma xenograft model was established with the KB-A1 cell line. DMC could sensitize the tumors to doxorubicin as indicated by a considerable reduction in tumor weight. DMC increased the intracellular accumulation of doxorubicin in KB-A1 cells. When KB-A1 cells were exposed to 10 microg/ml doxorubicin combined with 5, 10, 20 microM DMC for 4 hours, the intracellular concentrations of doxorubicin were increased 1.4-, 1.8-, 3.1-fold, respectively, in comparison with doxorubicin alone treatment. All results indicated that DMC had reversal effects on the multidrug resistance phenotype.

A dominant point mutation in a RINGv E3 ubiquitin ligase homoeologous gene leads to cleistogamy in Brassica napus

In the allopolyploid Brassica napus, we obtained a petal-closed flower mutation by ethyl methanesulfonate mutagenesis. Here, we report cloning and characterization of the Bn-CLG1A (CLG for cleistogamy) gene and the Bn-clg1A-1D mutant allele responsible for the cleistogamy phenotype. Bn-CLG1A encodes a RINGv E3 ubiquitin ligase that is highly conserved across eukaryotes. In the Bn-clg1A-1D mutant allele, a C-to-T transition converts a Pro at position 325 to a Leu (P325L), causing a dominant mutation leading to cleistogamy. B. napus and Arabidopsis thaliana plants transformed with a Bn-clg1A-1D allele show cleistogamous flowers, and characterization of these flowers suggests that the Bn-clg1A-1D mutation causes a pronounced negative regulation of cutin biosynthesis or loading and affects elongation or differentiation of petal and sepal cells. This results in an inhibition or a delay of petal development, leading to folded petals. A homoeologous gene (Bn-CLG1C), which shows 99.5% amino acid identity and is also constitutively and equally expressed to the wild-type Bn-CLG1A gene, was also identified. We showed that P325L is not a loss-of-function mutation and did not affect expression of Bn-clg1A-1D or Bn-CLG1C. Our findings suggest that P325L is a gain-of-function semidominant mutation, which led to either hyper- or neofunctionalization of a redundant homoeologous gene.

Tunable dual-band perfect absorbers based on extraordinary optical transmission and Fabry-Perot cavity resonance

Magnetic resonance is considered to be a necessary condition for metamaterial perfect absorbers, and dual-band absorbers can be composed of a pair of metallic layers with anti-parallel surface currents. We designed and fabricated a tunable dual-band perfect absorber based on extraordinary-optical-transmission (EOT) effect and Fabry-Perot cavity resonance. The idea and the mechanism are completely different from the absorber based on the near-field interaction. The important advantage of our structure is that we can switch a single-band absorber to a dual-band absorber by changing the distance between two metallic layers and/or incident angle. The peak originating from the EOT effect becomes significantly narrower, resulting in an increase of the Q-factor from 16.88 to 49. The dual-band absorber can be optimized to be insensitive to the polarization of the incident electromagnetic wave by slightly modifying the absorber structure.

A molecular approach to unraveling the genetics of sugarcane, a complex polyploid of the Andropogoneae tribe

Modern sugarcane varieties are complex aneuploids and typically have chromosome numbers in the 100-125 range with about 5-10% of them contributed by wild relatives, mainly Saccharum spontaneum, and the rest by S. officinarum. This particular genomic constitution was found favorable for mapping the S. spontaneum genome, using maize as a diploid reference for comparison. We conducted an analysis of 32 individuals derived from the selfing of variety SP 701006 using four isozymes and 53 maize probes which covered the whole maize genome. A total of 348 segregating bands were generated. Highly significant cosegregations enabled us to place 94 markers into 25 cosegregation groups. Eighteen of these groups involved S. spontaneum specific markers and might therefore mark S. spontaneum chromosomes in segregation. On the basis of probes in common, the 25 cosegregation groups could be assembled into eight tentative linkage groups, of which seven describe S. spontaneum chromosomes. A large degree of synteny between sugarcane and maize could be inferred, with a much lower rate of recombination in sugarcane.

Molecular mapping of wheat. Homoeologous group 3

A prerequisite for molecular level genetic studies and breeding in wheat is a molecular marker map detailing its similarities with those of other grass species in the Gramineae family. We have constructed restriction fragment length polymorphism maps of the A-, B-, and D-genome chromosomes of homoeologous group 3 of hexaploid wheat (Triticum aestivum L. em. Thell) using 114 F7-8 lines from a synthetic x bread wheat cross. The map consists of 58 markers spanning 230 cM on chromosome 3A, 62 markers spanning 260 cM on 3B, and 40 markers spanning 171 cM on 3D. Thirteen libraries of genomic or cDNA clones from wheat, barley, and T. tauschii, the wheat D genome donor, are represented, facilitating the alignment and comparison of these maps with maps of other grass species. Twenty-four clones reveal homoeoloci on two of the three genomes and the associated linkages are largely comparable across genomes. A consensus sequence of orthologous loci in grass species genomes is assembled from this map and from existing maps of the chromosome-3 homoeologs in barley (Hordeum spp.), T. tauschii, and rice (Oryza spp.). It illustrates the close homoeology among the four species and the partial homoeology of wheat chromosome 3 with oat (Avena spp.) chromosome C. Two orthologous red grain color genes, R3 and R1, are mapped on chromosome arms 3BL and 3DL.

Molecular mapping of wheat. Homoeologous group 2

A molecular-marker map of bread wheat having many markers in common with other grasses in the Gramineae family is a prerequisite for molecular level genetic studies and breeding in this crop species. We have constructed restriction fragment length polymorphism maps of the A-, B-, and D-genome chromosomes of homoeologous group 2 of hexaploid wheat (Triticum aestivum L. em. Thell) using 114 F7 lines from a synthetic x bread wheat cross and clones from 11 libraries. Chromosomes 2A, 2B, and 2D comprise 57, 60, and 56 markers and each spans about 200 cM. Comparisons between chromosomes are facilitated by 26 sets of homoeoloci. Genes mapped include a heterologous abscisic acid responsive locus cloned as pBS128, the epidermal waxiness inhibitor W21, and two presumed leaf rust and stem rust resistance genes. Anomalies suggesting ancestral rearrangements in chromosome 2B are pointed out and features of wheat group 2 chromosomes that are common to barley (Hordeum vulgare L.), rice (Oryza spp.), and T. tauschii are discussed.

Molecular genetic maps of the group 6 chromosomes of hexaploid wheat (Triticum aestivum L. em. Thell.)

Restriction fragment length polymorphism (RFLP) maps of chromosomes 6A, 6B, and 6D of hexaploid wheat (Triticum aestivum L. em. Thell.) have been produced. They were constructed using a population of F7-8 recombinant inbred lines derived from a synthetic wheat x bread wheat cross. The maps consist of 74 markers assigned to map positions at a LOD >= 3 (29 markers assigned to 6A, 24 to 6B, and 21 to 6D) and 2 markers assigned to 6D ordered at a LOD of 2.7. Another 78 markers were assigned to intervals on the maps. The maps of 6A, 6B, and 6D span 178, 132, and 206 cM, respectively. Twenty-one clones detected orthologous loci in two homoeologues and 3 detected an orthologous locus in each chromosome. Orthologous loci are located at intervals of from 1.5 to 26 cM throughout 70% of the length of the linkage maps. Within this portion of the maps, colinearity (homosequentiality) among the three homoeologues is strongly indicated. The remainder of the linkage maps consists of three segments ranging in length from 47 to 60 cM. Colinearity among these chromosomes and other Triticeae homoeologous group 6 chromosomes is indicated and a consensus RFLP map derived from maps of the homoeologous group 6 chromosomes of hexaploid wheat, tetraploid wheat, Triticum tauschii, and barley is presented. Key words : RFLP, wheat, linkage maps, molecular markers.

Investigation of the non-volatile resistance change in noncentrosymmetric compounds

Coexistence of polarization and resistance-switching characteristics in single compounds has been long inspired scientific and technological interests. Here, we report the non-volatile resistance change in noncentrosymmetric compounds investigated by using defect nanotechnology and contact engineering. Using a noncentrosymmetric material of ZnO as example, we first transformed ZnO into high resistance state. Then ZnO electrical polarization was probed and its domains polarized 180° along the [001]-axis with long-lasting memory effect (>25 hours). Based on our experimental observations, we have developed a vacancy-mediated pseudoferroelectricity model. Our first-principle calculations propose that vacancy defects initiate a spontaneous inverted domains nucleation at grain boundaries, and then they grow in the presence of an electrical field. The propagation of inverted domains follows the scanning tip motion under applied electrical field, leading to the growth of polarized domains over large areas.

Stability and Properties of Two-Dimensional Graphene Hydroxide

Systematic study of interaction between graphene and hydroxyls is carried out by first-principles calculations. Although single hydroxyl adsorbed on graphene presents magnetic properties, hydroxyls prefer to adsorb on graphene in pairs without magnetic properties. The formation energy of hydroxyl pairs with graphene is coverage-dependent, and the most stable structure is half-covered by hydroxyl pairs along zigzag chains with alternative sp2 and sp3 hybridization between carbon atoms. The bandgap of this structure is 0.97 eV in GW approximation, close to the bandgap of Si, and this structure is stable at room temperature. It is possible to build graphene-based electronic circuits from graphene hydroxide without the need for cutting or etching.

Bimetallic chips for a surface plasmon resonance instrument

In this work we have replaced a commonly used Au film with an Au/Ag bimetallic film working as the sensing chip in the commercial surface plasmon resonance (SPR) instrument, Biacore 3000. The bimetallic chip gives out sharper SPR dip than that by the chip made of an Au film. The applicability and stability of the bimetallic chip on the Biacore 3000 are tested by real-time monitoring of biological coupling processes between sulfamethoxazole (SMX) and anti-SMX, which is useful in rapid detection of contaminations in food products. The bimetallic chip performs stably in 6 times' usage and regeneration. Our experiment is helpful to push the bimetallic film into real applications in commercial SPR instruments.

Adsorption of an Mn atom on a ZnO sheet and nanotube: a density functional theory study

First-principles calculations based on density functional theory were performed to study the stable geometries, electronic structure and magnetic properties of the adsorption of a single Mn atom on a graphitic ZnO sheet and a (9, 0) single-wall ZnO nanotube. For the graphitic ZnO sheet, the Mn atom prefers to reside above the center of a hexagon (H site), with a relatively large binding energy of 1.24 eV. The H site is also the most stable site for adsorption of an Mn atom inside the ZnO nanotube, with a large binding energy of 1.47 eV. In both of these cases, the total magnetic moment is 5.0 μ(B) per Mn atom, which is the same as that of a free Mn atom. When the Mn atom is adsorbed outside the tube, the most energetically favorable site is the atop oxygen site. The magnetic moment is 3.19 μ(B) for this configuration. The smaller magnetic moment is mainly due to the strong p-d mixing of O and Mn orbitals. The different adsorption behaviors are related to the curvatures of the nanostructures.

Comparative flight performance of three important pest Adelphocoris species of Bt cotton in China

The massive adoption of Bt cotton throughout China has been accompanied by outbreaks of secondary pests such as Adelphocoris spp. (Heteroptera: Miridae). The Adelphocoris group primarily consists of three species: A. suturalis, A. fasciaticollis and A. lineolatus, which greatly differ in geographical distribution and seasonal dynamics. However, the underlying drivers of these differences remain to be understood. The study of flight behaviour of these three species can yield important insight into their spatial and temporal dynamics and help explain their distribution. We examined flight propensity of the three Adelphocoris spp. under a range of biological and environmental conditions using a computer-monitored flight-mill. Gender and mating status only had minor effects on flight performance in these species, while age exerted great effects on it. Flight capacity was low for one-day-old adults and increased with age until day 10-13, then gradually decreased afterwards. Temperature and relative humidity affected flight propensity, with 20-23 degrees C and 64-68% RH considered optimal for flight of all three species. Between-species comparisons indicated that A. suturalis and A. fasciaticollis had similar flight distance and duration, which were significantly greater than for A. lineolatus. Our findings provide crucial information for understanding geographical distribution and seasonal occurrence and for developing regional forecasting and pest management protocols for Adelphocoris species.

The Ti-B-N system: nanocomposite nc-TiN/a-(TiB2, BN) and nano-multilayer nc-TiN/a-TiBN thin films

The nanostructures and mechanical properties of nanocomposite nc-TiN/a-(TiB2, BN) and nanostructured multilayers nc-TiN/a-TiBN were investigated using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), microindentation, and stress measurements. It was found that the monolayer Ti-B-N thin films consisted of nanometer-sized crystalline (nc-) Ti(N, B) embedded into amorphous (a-) (TiB2, BN) matrix. When B content was below approximately 16 at.%, two different-sized nanocrystallites with mean grain sizes of approximately 3 and 9 nm respectively were embedded in a-TiB2. With increasing B incorporation (> approximately 27 at.%), more uniform nanograins was embedded a-(TiB2, BN). Incorporation of B not only decreased the size of nanocrystallites, but also gave rise to twinning deformation in nanocrystallites. A maximum hardness of approximately 44 GPa was achieved at B content of 19 at.%. It was also found that the nanostructure and mechanical behaviors of nc-TiN/a-TiBN multilayers was dependent on the modulation length (bilayer thickness A). Decrease of Lambda made the preferred orientation of nc-TiN gradually transform from (200) to (111). A maximum hardness of approximately 30 GPa was achieved at Lambda = 1.8 nm. Deflection from this Lambda value decreased hardness. By contrast, the residual compressive stress value monotonically increased with decrease of A. The enhancement of the hardness was due to the coherent stresses and the structural barriers to dislocation motion in the interface.

Magneto-optical enhancement through gyrotropic gratings

Diffracted magneto-optical (MO) effects are numerically investigated for one-dimensional lossy gyrotropic gratings in the zeroth and the first orders for the polar magnetization by utilizing the rigorous coupled-wave approach implemented as an Airy-like internal-reflection series. The simulated Kerr spectra agree well with the experimental ones. The dependence of the MO Kerr enhancement on the grating depth in the first-order diffraction, compared with that in the zeroth one, is illustrated, and the diffracted MO Faraday effect is theoretically investigated as well. Such a MO enhancement through the gyrotropic gratings is superior to the conventional MO devices and magneto-photonic crystals. The potential applications are also suggested.

Inhibitory effects of flavonoids from Hypericum perforatum on nitric oxide synthase

The inhibitory effects of six flavonoids from Hypericum perforatum were assessed spectrophotometrically using nitric oxide synthase (NOS) in blood and cerebral homogenate of rats. Of the assayed compounds, quercetin and hyperoside showed concentration-dependent enzyme inhibitory actions. The IC50 values of quercetin for inhibiting NOS in rat cerebral homogenate and blood were 63.06 and 57.54 microM, and those of hyperoside 56.23 and 158.49 microM, respectively. The competitive patterns were discerned with the inhibition of the two flavonoids on NOS in serum and cerebral homogenate (except a mixed type inhibition was observed with quercetin in inhibiting cerebral NOS). Furthermore, similar inhibitions were found for quercetin upon NOS in cerebral homogenate and blood. However, a stronger inhibitory effect of hyperoside on the enzyme was discerned in cerebrum than in blood. These results suggested that the galactose moiety in hyperoside may be associated with the selectivity of the NOS inhibition.

Twenty-year follow-up of the Carpentier-Edwards standard porcine bioprosthesis in the Oriental population

AIM

The 20-year period long-term results of porcine bioprosthetic valve use are limited. In addition, the majority of these reports come from Western countries. Given the scanty information reported in Oriental countries, this study was therefore designed to examine 20-year long-term results in patients who received a Carpentier-Edwards porcine bioprosthetic valve in an effort to contribute further information on the long-term clinical performance of porcine prosthetic valves from a viewpoint of results in the Oriental population.

METHODS

From July 1979 to April 2001, 82 patients received valve replacement with a standard Carpentier-Edwards porcine valve. There were 40 men and 42 women with a mean age of 42.3+/-15.1 years (range 16 to 73 years). Follow-up time extended more than 20 years (mean 10.9+/-3.2 years, range 0.5 to 21.5 years ) for a total of 719.5 patient-years.

RESULTS

The overall operative mortality was 16.9% (14 of 83 procedures). At 5, 10, 15, and 20 years, the actuarial survival rate of patients was 71.7%, 66.9%, 55.5%, and 44.4%, respectively. Actuarial estimates of freedom from structural valvular deterioration (SVD) at 5, 10, 15, and 17 years were 96.3%, 64.0%, 24.3%, and 24.3%, respectively; from reoperation 96.3%, 64.5%, 24.5%, and 24.5%; from operated valvular endocarditis 96.8%, 92.6%, 92.6%, and 92.6%; and from overall thromboembolism 96.3%, 88.5%, 67.2%, and 52.2%. In normal sinus rhythm, actuarial estimates of freedom from thromboembolism at 5, 10, 15, and 17 years were 100.0%, 100.0%, 81.8%, and 81.8%, respectively. Whereas for those in patients with atrial fibrillation, the estimates of freedom from thromboembolism were 94.5%, 82.4%, 57.7%, and 38.5%.

CONCLUSION

This study demonstrates the very satisfactory 20-year period long-term performance of freedom from bleeding events, thromboembolism (except in patients with atrial fibrillation), and valvular endocarditis in Oriental patients undergoing replacement with a porcine valve. However, the remarkable rate of SVD and reoperation ensued at 6 years after bioprosthesis implanted which does not differ from the series reported from Western countries.

Bioaccumulation of nickel from aqueous solutions by genetically engineered Escherichia coli

This study constructed a genetically engineered Escherichia coli JM109 which simultaneously expressed nickel transport system and metallothionein to remove and recover Ni(2+) from aqueous solution. Bioaccumulation process was rapid and followed linearized Langmuir isotherm. A more than six-fold increase of Ni(2+) binding capacity was obtained by genetically engineered E. coli cells compared with original host E. coli cells. A pH assay showed genetically engineered E. coli cells accumulated Ni(2+) effectively over a broad range of pH (4-10). The presence of 1000 mg/L Na(+) and Ca(2+), or 50mg/L Cd(2+) or Pb(2+) did not have a significant effect on Ni(2+) bioaccumulation, while Mg(2+), Hg(2+) and Cu(2+) posed a severe adverse influence on Ni(2+) uptake by genetically engineered E. coli. Furthermore, genetically engineered E. coli cells did not require extra nutrients for Ni(2+) bioaccumulation.

Cystic left atrium myxoma--a rare case report

Myxoma is the most common primary tumor of heart. The typical picture of myxoma under echocardiography is a solid, dense echo mass and left atrium is the most common site to find it. The cystic form of myxoma is vary rare. We report a patient who received echocardiographic examination under impression of mitral valve stenosis. A multilobulated cystic mass which was like a hydatid cyst was found in the left atrium and atrioventricular flow was affected by this mass. After tumor resection, myxoma with internal hemorrhage was proved by pathology. No further recurrent myxoma was found during follow-up echocardiographic examination.

A mixed-valence manganese(III)-manganese(IV) di-mu-oxo complex, [(cyclam)MnO]2(ClO4)2(NO3)

The title dinuclear di-mu-oxo-bis[(1,4,8,11-tetraazacyclotetradecane-kappa(4)N)manganese(III,IV)] diperchlorate nitrate complex, [Mn(2)O(2)(C(10)H(24)N(4))(2)](ClO(4))(2)(NO(3)) or [(cyclam)MnO](2)(ClO(4))(2)(NO(3)), was self-assembled by the reaction of Mn(2+) with 1,4,8,11-tetraazacyclotetradecane in aqueous media. The structure of this compound consists of a centrosymmetric binuclear [(cyclam)MnO](3+) unit, two perchlorate anions and one nitrate anion. While the low-temperature electron paramagnetic resonance spectra show a typical 16-line signal for a di-mu-oxo Mn(III)/Mn(IV) dimer, the magnetic susceptibility studies also confirm a characteristic antiferromagnetic coupling between the electronic spins of the Mn(IV) and Mn(III) ions.

Atrioventricular block in Kearns-Sayre syndrome: a case report

The Kearns-Sayre (K-S) syndrome which includes the triad of progressive external ophthalmoplegia, pigment retinopathy, and disorder of cardiac conduction was first described in 1958. The mitochondria disorder is believed to be the cause of this syndrome. Involvement of the cardiac conduction system is the most importent prognostic factor in K-S syndrome. A 34-year-old male K-S syndrome patient, manifesting as ptosis and weakness of limbs since the age of 15 years, suffered from dizziness and weakness. Twelve-lead eletrocardiography (ECG) showed a 2:1 atrioventricular (AV) block with slow ventricular rate. Intermittent complete AV block, complete left bundle branch block and torsades de pointes were noted in Holter ECG. The electrophysiology study demonstrated prolonged HV interval (85 ms) on conduction beat and infra-His block on non-conduction beat. A VVIR mode of permanent pacemaker was implanted and the patient's condition was stable during this period of follow-up.

[Extraction and analysis of profenofos residue in tomato and cabbage by gas chromatography-flame photometric detector]

A quick and effective extraction and clean-up method of profenofos residue in tomato and cabbage is presented. Tomato and cabbage samples were homogenized with a mixture of acetone-hexane (1:1, V/V) using a mechanical homogenizer. The resultant homogenate was cleaned-up by adding active carbon and then filtered under reduced pressure. The filter cake was extracted twice with the same solvent mixture. The filtrates were combined and transferred into a separatory funnel. The organic layer was separated and evaporated to dryness using a rotary evaporator. The residue was dissolved in 2 mL of acetone and transferred into a small glass vial and then determined by GC on a 5% OV-101 Chromosorb W-HP column with flame photometric detector. The results showed that this analytical method can be used for an accurate determination of profenofos residues in tomato and cabbage. The minimum detectable concentration of profenofos in samples was 0.06 mg/kg. The recoveries of profenofos in tomato and cabbage were in the range of 96.2%-105.9% and 94.7%-102.3%, respectively. The relative standard deviations were in the range of 3.7%-4.9% and 3.7%-5.0%, respectively. The tomato and cabbage samples were collected 3 weeks after applying profenofos in the field, and the contents of profenofos were determined. The average contents of profenofos in tomato and cabbage were (13.8 +/- 0.8) mg/kg and (14.4 +/- 0.7) mg/kg, respectively.

Effects of isomalto-oligosaccharides on bowel functions and indicators of nutritional status in constipated elderly men

OBJECTIVES

To evaluate effects of isomalto-oligosaccharides (IO) on the bowel function and nutritional status of elderly men.

METHODS

Seven older male subjects participated in this study that consisted of a 30-day control low fiber period followed by a 30-day IO-supplemented (10 g active components) experimental period. Bowel functions such as defecation, enema use and bloating were monitored daily. Fecal characteristics such as wet and dry stool weights, stool moisture, pH and short-chain fatty acid contents were determined on five-day fecal composites collected in each period. Feces were further fractionated into plant, bacterial and soluble fractions to determine the bases for the increase in stool weight. Nutritional status of subjects was assessed with anthropometric parameters, nutrient intake and biochemical measurements.

RESULTS

Incorporation of IO significantly increased the defecation frequency, wet stool output and dry stool weight by twofold, 70% and 55%, respectively. Fecal acetate and propionate concentrations significantly increased by nearly two and a half fold with IO supplement. The increase in stool bulk was mainly attributed by increased bacterial mass. Mean serum sodium concentration decreased in the experimental period while other blood characteristics did not change significantly. Anthropometric parameters and nutrient intake remained constant throughout the study.

CONCLUSIONS

Consumption of IO effectively improved bowel movement, stool output and microbial fermentation in the colon without any adverse effect observed in this study. Therefore, supplementation of IO into ordinary low fiber diets may be practical in relieving constipation in the elderly population.

The effect of fluvastatin on fibrinolytic factors in patients with hypercholesterolemia

Several studies have shown cardiovascular benefit in treating hypercholesterolemia with HMG-CoA reductase inhibitor. However, in addition to the lowering of cholesterol, the beneficial effects of this inhibitor reflect other pharmacological activities. Whether these beneficial effects are partly mediated by changes in fibrinolytic factors remains to be proven, since clinical studies on the effects of HMG-CoA reductase inhibitors on fibrinolytic factors have not yielded consistent results. The purpose of this study was to evaluate the effects of fluvastatin on fibrinolytic factors in hypercholesterolemic patients. After 6 weeks on a low-fat, low-cholesterol diet, 23 outpatients known to have primary hypercholesterolemia with low density lipoprotein cholesterol (LDL-C) > or = 130 mg/dl with at least 2 risk factors or fasting LDL-C > or = 160 mg/dl were selected for the study. Venous blood samples were collected at baseline and at 8 weeks after fluvastatin therapy (40 mg/day) to measure of tissue plasminogen activator (t-PA), plasminogen activators inhibitor-1 (PAI-1), fibrinogen, D-dimer and lipid profile. After 8 weeks of therapy, fluvastatin reduced serum cholesterol by 11% (261.9 mg/dl vs 233.2 mg/dl, P < 0.01) and LDL-C by 22% (191.9 mg/dl vs 149.3 mg/dl, P < 0.01). D-dimer was significantly decreased (0.38 ng/L vs 0.28 ng/L, P = 0.02) and tPA, PAI-1 and fibrinogen tended to decrease after therapy. Fluvastatin therapy improved fibrinolytic profile; the result of this study may in part explain the benefit of HMG-CoA reductase inhibitor on cardiovascular system other than lipid lowering.