CRISPR/Cas9-based precise excision of SlHyPRP1 domain(s) to obtain salt stress-tolerant tomato

KEY MESSAGE

CRISPR/Cas9-based multiplexed editing of SlHyPRP1 resulted in precise deletions of its functional motif(s), thereby resulting in salt stress-tolerant events in cultivated tomato. Crop genetic improvement to address environmental stresses for sustainable food production has been in high demand, especially given the current situation of global climate changes and reduction of the global food production rate/population rate. Recently, the emerging clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas)-based targeted mutagenesis has provided a revolutionary approach to crop improvement. The major application of CRISPR/Cas in plant genome editing has been the generation of indel mutations via error-prone nonhomologous end joining (NHEJ) repair of DNA DSBs. In this study, we examined the power of the CRISPR/Cas9-based novel approach in the precise manipulation of protein domains of tomato hybrid proline-rich protein 1 (HyPRP1), which is a negative regulator of salt stress responses. We revealed that the precise elimination of SlHyPRP1 negative-response domain(s) led to high salinity tolerance at the germination and vegetative stages in our experimental conditions. CRISPR/Cas9-based domain editing may be an efficient tool to engineer multidomain proteins of important food crops to cope with global climate changes for sustainable agriculture and future food security.

A transdiagnostic examination of anxiety and stress on executive function outcomes in disorders with social impairment

BACKGROUND

Executive function (EF) difficulties characterise a number of psychiatric conditions and EF impairment may be a predisposing factor and/or consequence of anxiety and stress. The aim of the study was to examine EF factors in a mixed clinical cohort (Autism Spectrum Disorder and Social Anxiety Disorder) characterised by social impairment and investigate the influence of trait anxiety and state-based depression, anxiety and stress.

METHODS

In Study 1, a factor analysis identified EF and non-EF latent factor structures (N=205). In Study 2, (N=137) multiple regression analyses investigated the association between trait anxiety and state based depression, anxiety and stress, on EF and non-EF cognitive domains and on the two composite indices of the Behavioural Rating Inventory of Executive Function (BRIEF).

RESULTS

Trait anxiety was associated with better performance on neuropsychological measures of EF while state-based stress was associated with lower EF performance. A dissociation was observed between trait anxiety and state stress on the two behavioural indices of the BRIEF. Depression, anxiety and stress did not predict performance on non-EF cognitive domains.

LIMITATIONS

The cross-sectional design precludes cause-effect conclusions, further only self-report measures of affect were utilised and our performance measures of EF did not include a working memory test.

CONCLUSIONS

The results demonstrate that trait anxiety and state-based stress influence EF processes across disorders with social impairment. The transdiagnostic efficacy of this finding can facilitate remediation strategies, it may also contribute to individuals with Autism Spectrum Disorder gaining better access to mental health services.

CRISPR/Cas-based precision genome editing via microhomology-mediated end joining

Gene editing and/or allele introgression with absolute precision and control appear to be the ultimate goals of genetic engineering. Precision genome editing in plants has been developed through various approaches, including oligonucleotide-directed mutagenesis (ODM), base editing, prime editing and especially homologous recombination (HR)-based gene targeting. With the advent of CRISPR/Cas for the targeted generation of DNA breaks (single-stranded breaks (SSBs) or double-stranded breaks (DSBs)), a substantial advancement in HR-mediated precise editing frequencies has been achieved. Nonetheless, further research needs to be performed for commercially viable applications of precise genome editing; hence, an alternative innovative method for genome editing may be required. Within this scope, we summarize recent progress regarding precision genome editing mediated by microhomology-mediated end joining (MMEJ) and discuss their potential applications in crop improvement.

[The first identification of epidemic clone of enterotoxic Escherichia coli O∶6 serogroup highly associated with azithromycin resistance in Shanghai]

Objective: To investigate the molecular characterization of adult diarrhea cases caused by enterotoxic Escherichia coli (ETEC) and explore the practical model of epidemiology for laboratory technique and data needs based on the surveillance network. Methods: Epidemiological design and sampling targeted adult cases ETEC caused diarrhea in epidemic season. The enterotoxin type, serogroup, resistance, colonization factor and molecular type of ETEC were identified. Multiple dynamic phenotypic characteristics of ETEC were indicated by multidimensional and multivariable data. Results: From 2016 to 2018, 84 eligible ETEC strains were detected. The dominant serums/toxins were O∶6 (STh), O∶25 (LT), O∶159 (STh), O∶153 (STh). O∶6 (STh+CS21), which replaced O∶25 and O∶159 as the popular clones in 2018. Six cases of O∶153 (STh+CFA/I+CS8+PT34) in outbreak in 2017 were imported ones. The resistance rates of ETEC strains detected in adults to sulfasoxazole, naproxinic acid, ampicillin and azithromycin were more than 30%, multidrug resistance (MDR) reached 58.3%. Serum/toxin types suggested that attenuated strains were more likely to become MDR. Molecular typing confirmed that the genetic similarity of the dominant clone of O∶6 serogroup (PT20-24) was higher than O∶25 and O∶159. There was a high correlation between the minimal inhibitory concentration (MIC) of azithromycin and the resistant gene mphA (87.5%, 28/32). O∶6 (STh+CS21+mphA) resistant clone was first detected in 2016. Conclusion: A new epidemic clone in adult ETEC diarrhea cases in Shanghai was O∶6 (STh+CS21+mphA). For the first time the association between azithromycin resistance gene mphA and a serum group of ETEC was observed. Multidimensional and multivariate analysis techniques based on epidemiology can help reveal the potential transmission pattern of ETEC for the accurate surveillance and early warning of outbreaks.

[Expression of high-mobility group box-Ⅰ and N-methyl-D-aspartate receptor in status epilepticus]

Objective: To investigate the expression changes of high mobility group box-1 (HMGB1) and the 2B receptor of N- methyl -D- aspartate receptor (NR2B) in status epilepticus (SE). Methods: (1) Primary hippocampal neurons from SD rats with 16 to 18 days of fetal age were cultured in vitro for 7 days, and exposed to Mg(2+) free media for 3 hours. Those cultured neurons were randomly divided into control group and intermittent hypoxia group. (2) SD rats with similar weight were selected and randomly divided into control group and SE model group. The rat model with SE was established by an intraperitoneal injection of lithium chloride-piloearpine (LI-PILO). Real-time PCR technique was used to detect the expression of HMGB1 and NR2B mRNA. Results: In Sombati's cell model cultured in normal concentration of oxygen, the HMGB1 mRNA expression levels were 0.005 01±0.000 54, 0.026 76±0.003 75, 0.003 52±0.000 33, and the NR2B mRNA expression levels were 0.008 84±0.000 69, 0.012 23±0.000 90, 0.029 11±0.000 71, respectively, at 2, 4 and 6 h; compared with the expressions of HMGB1 and NR2B mRNA at the same time points of Sombatis cell model groups, the differences were also significant (all P<0.05). After the successful establishment of epilepsy model, the HMGB1 mRNA expression levels were 0.000 11±0.000 09, 0.000 18±0.000 01, 0.000 11±0.000 01, and the NR2B mRNA expression levels were 0.196 12±0.009 41, 0.232 11±0.006 27, 0.272 48±0.005 84, respectively, at 6, 8 and 10 h; compared with the expressions of HMGB1 and NR2B mRNA at the same time points of control groups, the differences were all significant (all P<0.05). Conclusion: HMGB1 mRNA expression levels increase at 2, 4 h, decrease at 6 h in the Sombati's cell model in normal oxygen culture, while increase at 6, 8 h, and decrease at 10 h in LI-PILO induced rat model with SE; the NR2B mRNA relative expression increases with time in both the Sombati's cell model in normal oxygen culture and rat model of SE.

[Factors associated with commercial sexual behavior among men who have sex with men in Shenzhen, China, in 2011-2015]

Objective: To investigate the status and factors associated with commercial sexual behavior among men who have sex with men (MSM) in Shenzhen. Methods: A convenience sampling method was used to recruit MSM in Shenzhen from 2011 to 2015. Questionnaire-based interviews were conducted on a one-on-one basis. Data were collected, including socio-demographic information, HIV testing history, history of blood donation and drug abuse in the last 2 years, self-reported sexual orientation, role in homosexual behavior, and experience serving as a male sex worker and/or as a client of male sex workers. Blood samples (5 ml) were taken and tested for treponema pallidum and HIV antibodies. The rate of MSM serving as male sex workers among different age groups was analyzed using the Cochran-Armitage trend test. Factors associated with commercial sexual behavior were analyzed by univariate logistic regression and multivariate unconditional logistic regression. Results: Among the 3 040 MSM recruited, 341 (11.2%) reported having served as male sex worker. The prevalence rates of syphilis, HIV, and syphilis-HIV co-infection among all recruited MSM were 18.3% (556/3 040), 9.8% (297/3 040), and 5.1% (154/3 040), respectively. The prevalence rates of syphilis, HIV, and syphilis-HIV co-infection among those who served as male sex worker were 27.0% (92/341), 16.4% (56/341), and 8.8% (30/341), respectively, and the prevalence rates among MSM with no experience as male sex worker were 17.2% (464/2 699), 8.9% (241/2 699), and 4.6% (124/2 699), respectively. Compared with non-male sex worker MSM, male sex worker had a significantly higher prevalence rates of syphilis, HIV, and syphilis-HIV co-infection (with χ² values of 19.41, 19.28, and 11.12, and P-values of <0.001,<0.001, 0.001, respectively). The results of the multivariate logistic regression analysis indicate that>30-year-old MSM or education level of college or above, reside in Shenzhen for 0.5-3.0 years or the living years above 3.0 years are less likely to serve as male sex worker compared with<30-year-old MSM, education level of high school or below, who reside in Shenzhen for less than 0.5 years; the OR (95%CI) values were 0.55 (0.42-0.71), 0.10 (0.06-0.14), 0.46 (0.31-0.68), and 0.23 (0.16-0.33), respectively. MSM having a monthly income of >5 000 yuan, drug abuse history, experience as male sex worker clients, and self-reported insertive and receptive anal sex behaviors were more likely to have experience serving as male sex worker compared with those having a monthly income of <3 000 yuan (OR=2.57, 95%CI: 1.85-3.57), no drug abuse history (OR=3.23, 95% CI: 2.14-4.87), no experience as male sex worker clients (OR =1.50, 95% CI: 1.04-2.15) and who engage in predominantly insertive anal sex behaviors (OR=1.77, 95% CI: 1.34-2.35). Conclusion: Age, education level, duration of residence in Shenzhen, monthly income, history of drug abuse, role in homosexual activity, and had experience commercial sex activity were associated with serving as a male sex worker among MSM. These factors need to be considered when designing syphilis/HIV prevention programs for MSM.

[Investigation of dose-dependent association between bedtime routines and sleep outcomes in infants and toddlers]

Objective: To investigate the current bedtime routine among Chinese children less than 3 years of age and explore its dose-dependent association with sleep duration and sleep quality. Method: Healthy full-term born children aged 0-35 months were selected by stratified cluster random sampling method from 8 provinces in China following the "Hospital of Province-City-County" sampling technical route during 2012-2013.Brief Infant Sleep Questionnaire(BISQ) was used to assess sleep conditions of these children.Children's personal and family information was obtained by Shanghai Children's Medical Center Socio-demographic Questionnaire.Both of these questionnaires were filled in by parents. The effects of bedtime routine on children's sleep duration and quality were analyzed by multivariate analysis of variance. Result: The children's average age was(12±10) months(n=1 304), of whom 689 were males (52.8%, 689/1 304). There were 48.5%(632/1 304)of the parents reported that their children had not established regular sleep routines. There was a consistent dose-dependent association between bedtime routine and sleep duration, as well as other indicators for sleep quality (all P<0.05). The more regular the sleep routines, the longer the sleep duration, the earlier the children went to sleep, the shorter the sleep onset latency, the fewer the nighttime wakeup and the shorter the nighttime waking.The nighttime sleep duration was significantly longer for those with a bedtime routine 'every night' than those who 'never' had a bedtime routine (9.5(95%CI: 9.4-9.6)vs. 8.9(95%CI: 8.6-9.3)h, t=3.345, P=0.001). Compared with children who never had bedtime routines, children with regular bedtime routines had fewer night wakeup (1.3(95%CI: 1.2-1.4) vs. 2.4( 95%CI: 2.0-2.9), t=3.182, P=0.001) and shorter night waking duration(16.6(95%CI: 14.6-18.8) vs. 59.2 (95%CI: 47.0-72.7)min, t=6.383, P<0.01). Conclusion: The percentage of children who have established regular bedtime routine is low in China. There is significant dose-dependent association between regular bedtime routine and sleep outcomes, especially sleep quality. The more regular the sleep routines, the better the sleep quality.

[Update on pubertal development among primary school students in Shanghai, 2014]

Objective: To investigate the current prevalence of pubertal development in healthy Shanghai schoolchildren. Methods: This study was a cross-sectional investigation focused on current pubertal development conducted in healthy Shanghai schoolchildren by multi-stage cluster sampling. The sample included 17 571 children in grades 1-5 investigated in June 2014. The data were weighted by inverse probability weighting (IPW) to make them more representative. At examination, stages of breast and pubic hair development were rated according to the Tanner method. Testicular volume was determined. Data on menarche and spermatorrhea were collected by the status quo method. The rates of precocious puberty, breast, and pubic hair development of Tanner stage ≥Ⅱ in girls aged 6-7 years, menarche in girls aged 6-9 years, and testicular volume ≥4 ml and pubic hair development of Tanner stage ≥Ⅱ in boys aged 6-8 years were calculated. All the data were weighted by IPW. Results: After data processing, 16 197 children's data were analyzed. In girls aged 6-7 years, 17.2% and 2.5% showed evidence of breast and pubic hair development at Tanner stage ≥Ⅱ, respectively. In girls aged 6-9 years, 0.3% had experienced menarche. Schoolgirls' rate of menarche was 4.7%. In girls aged 6-7 years, 19.0% were diagnosed with precocious puberty according to the classic criteria. In boys aged 6-8 years, 1.7% had testicular volume ≥4 ml, and 0.6% showed evidence of pubic hair development at Tanner stage ≥Ⅱ. Schoolboys' incidence rate of spermatorrhea was 0.1%. In boys aged 6-8 years, 2.3% were diagnosed with precocious puberty according to the classic criteria. All the numbers above were weighted. Conclusion: Proper education on adolescence and sex is essential for Shanghai schoolchildren.

The nutrition contribution of dietary supplements on total nutrient intake in children and adolescents

BACKGROUND/OBJECTIVES

The use of dietary supplements (DSs) by children and adolescents is increasing. The aim of this study was to identify the characteristics of DS users and examine the nutritional contributions of DSs to total nutrient intakes in children and adolescents, using data obtained from a national survey.

SUBJECTS/METHODS

In total, 3134 subjects aged 9-18 years who participated in the 4th Korea National Health and Nutrition Examination Survey (2007-2009) were selected; the survey included 24-h recall questions on food intake and questions on DS use over the past year. Nutrient intakes from DSs were calculated using the aid of a label-based database on such supplements, and individual total nutrient intakes were derived by combining information on the foods and DSs consumed by each subject.

RESULTS

There were 895 DS users (28.5%), 85.2% of whom (n=577) had complete DS nutrient information and were therefore defined as identified-DS users. Identified-DS users were slightly younger and had a greater household income and better nutritional knowledge than did non-users. The most frequently consumed type of supplement was a 'multivitamin and minerals' complex. For total nutrient intake, identified-DS users had a significantly higher intake of most of the nutrients, except for macronutrient and sodium than non-users. In all identified-DS users, the contribution of vitamins and minerals from DSs to total nutrient intake was higher than energy and macronutrients.

CONCLUSIONS

DS use by children and adolescents can improve micronutrient status, but it also increases the risk of excessive intake of certain vitamins and minerals.

Dietary supplement use and its effect on nutrient intake in Korean adult population in the Korea National Health and Nutrition Examination Survey IV (2007-2009) data

BACKGROUND/OBJECTIVES

Although there is an increasing trend of dietary supplement (DS) use, few researches have evaluated nutrient intake from DS. This study aimed to establish a nutrient database (NDB) for DS and estimate the effect of DS on total nutrient intake by Korean adults.

SUBJECTS/METHODS

The NDB for DS was established using the label information of products reported in the Korea National Health and Nutrition Examination Survey (KNHANES) IV. Of the 16,031 participants who were ≥20 years old, 2053 products were reported as being taken by 5606 subjects. But nutrient composition could be identified by searching product name only in 1158 products consumed by 3844 subjects (DS users). Total nutrient intake of DS users was obtained by combining intakes from diet and DS.

RESULTS

Dietary supplement use was higher in women, in middle-aged people and in those with higher education and low smoking and drinking preferences. Nutrients obtained from food were higher in DS users than in nonusers for most nutrients, particularly in women. When total nutrient intake was evaluated in DS users, the percentage of subjects whose intake was below the estimated average requirement for Koreans decreased for several vitamins and minerals, but the percentage of subjects whose intake was above the tolerable upper intake levels increased for vitamin A, vitamin C and iron.

CONCLUSIONS

The newly developed NDB for DS will be an important resource for more accurate assessment of nutrient intake as well as evaluation of the relationship between nutrition and health. Further research is needed to update a more comprehensive NDB applicable to diverse populations.

Impact of MTHFR polymorphisms on methylation of MGMT in glioma patients from Northeast China with different folate levels

Hypomethylation of the O6-methylguanine-DNA-methyltransferase (MGMT) promoter in glioma cells has been associated with temozolomide resistance. S-adenosylmethionine (SAM), which is produced during folate metabolism, is the main source of methyl groups during DNA methylation. As a key enzyme during folate metabolism, polymorphisms of 5,10-methylenetetrahydrofolate reductase (MTHFR) may regulate folate end-products. We investigated the effect of typical polymorphisms of MTHFR (C677T and A1298C) on MGMT methylation based on different serum folate levels in patients with glioma from Northeast China. A total of 275 patients with glioma and 329 without malignant tumors were tested. Serum folate concentration was assayed by using the electrochemiluminescence immunoassay. MTHFR polymorphisms were detected by Taqman-Fluorescence quantitative polymerase chain reaction (PCR). Methylation-specific PCR was used to assess MGMT methylation. The constituent ratio of glioma patients below the serum folate biological reference value was significantly higher than that of the control population (P < 0.001). In patients with oligodendroglioma and glioblastoma, heterozygotes for the A1298C mutation were found in higher frequency than homozygotes or wild types (oligodendroglioma, P < 0.001; glioblastoma, P < 0.01). When grouped by the median or biological reference value of serum folate, only homozygotes for C677T with low levels of folate were significantly associated with decreased methylation of MGMT (median, P < 0.001; biological reference value, P = 0.036). These data suggest that, in combination with a negative folate balance in glioma patients, T/T genotypes in MTHFR C677T may be associated with MGMT demethylation.

Evaluation of the efficacy of immunocastration vaccine composed of gonadotrophin-releasing hormone conjugated with Salmonella typhimurium flagellin in rats

Immunocastration is an alternative method to replace surgical castration that is commonly performed in domestic and pet animals. In this study, a new immunocastration vaccine was developed, and its efficacy was evaluated in male rats. Six tandem copies of gonadotrophin-releasing hormone (GnRH) peptide were genetically fused to Salmonella typhimurium flagellin fljB (STF2) that is a ligand of toll-like receptor 5 (TLR5). The recombinant STF2-GnRH protein expressed in Escherichia coli was used as the immunocastration vaccine. Sixteen male rats were equally assigned to four groups. Excluding the control rats, three groups were immunized with 100, 200 and 400 μg of the STF2-GnRH vaccine, respectively. All of the immunized rats developed significantly higher titres of antibodies to GnRH than the control rats. The size and weight of both testes and epididymides from the immunized rats were significantly smaller than those of the control rats. Testicular tissues in the immunized rats demonstrated atrophy of seminiferous tubules and decreased numbers of both spermatogonia and spermatocytes. These data indicate that the newly developed STF2-GnRH vaccine has a potent immunogenicity to GnRH and efficiently suppresses the development of testes in rats.

Polar nanodomains and giant converse magnetoelectric effect in charge-ordered Fe2OBO3

The magnetoelectric coupling and polar nanodomains in the charge-ordered Fe2OBO3 have been extensively studied from room temperature down to 100 K. In situ TEM investigations demonstrate that the charge-ordering transition characterized by an incommensurate modulation could evidently result in remarkable polar nanodomains at low temperatures. This kind of nanodomain could play a critical role in triggering a high dielectric constant and notable dielectric dispersion as observed in Fe2OBO3. Moreover, measurements of the magnetoelectric coupling under electrical field demonstrate the existence of giant electrically induced changes in magnetization around the magnetic transition.

Human cytomegalovirus IE86 protein binds to cellular Mcm3 protein but does not inhibit its binding to the Epstein-Barr virus oriP in U373MG-p220.2 cells

Human cytomegalovirus (HCMV) or its immediate-early IE86 protein alone induces cell cycle in quiescent primary human foreskin fibroblasts (HFFs), but blocks its progression at the G1/S interphase and inhibits cellular DNA synthesis by a mechanism that is not clearly understood. It is assumed that, in this phenomenon, the binding of minichromosome maintenance (Mcm) proteins to replication origins is blocked. In this work, we analyzed the initiation of DNA replication in HCMV-permissive U373MG cells and used oriP of Epstein-Barr virus (EBV) as a simplified model of a cellular replication origin. Using U373MG cells we found that HCMV IE86 protein was bound to Mcm3, but did not inhibit the cellular DNA synthesis. Using U373MG-p220.2 cells carrying EBV oriP and expressing Epstein-Barr nuclear antigen 1 (EBNA1), we found that EBNA1 as well as Mcm3 were bound to oriP and that neither HCMV nor IE86 protein inhibited the binding of Mcm3 to oriP. Differences between the effects of HCMV on the cell cycle progression in HFFs and U373MG cells are discussed.

KEYWORDS

cell cycle; Human cytomegalovirus; DNA replication.

Structural properties and superconductivity of SrFe(2)As(2 - x)P(x) (0.0 ≤ x ≤ 1.0) and CaFe(2)As(2 - y)P(y) (0.0 ≤ y ≤ 0.3)

The SrFe(2)As(2 - x)P(x) (0.0 ≤ x ≤ 1.0) and CaFe(2)As(2 - y)P(y) (0.0 ≤ y ≤ 0.3) materials were prepared by a solid-state reaction method. X-ray diffraction measurements indicate that the single-phase samples can be successfully obtained for SrFe(2)As(2 - x)P(x) (0.0 ≤ x ≤ 0.8) and CaFe(2)As(2 - y)P(y) (0.0 ≤ y ≤ 0.3). Visible contraction of the lattice parameters is determined due to the relatively smaller radius of P ions in comparison with that of As. The spin-density-wave (SDW) instability associated with the tetragonal to orthorhombic phase transition is suppressed noticeably in both systems following the increase in P content. The highest superconducting transitions are observed at about 27 K in SrFe(2)As(1.3)P(0.7) and at about 13 K in CaFe(2)As(1.925)P(0.075), respectively. Structural analysis suggests that lattice contraction could notably affect the superconductivity in these materials.

Clinical features of patients with multiple sclerosis from a survey in Shanghai, China

Objective

To describe clinical features of patients with multiple sclerosis (MS) in Shanghai, China.

Methods

Prevalent patients with MS were identified and investigated by a network of physicians in 11 districts of Shanghai during the period from 1 September 2004 to 31 August 2005. Admission registries of each hospital in the study area were checked systematically for patients with a diagnosis of MS, neuromyelitis optica or other demyelinating disorders. All patients with collected information were evaluated by four senior neurologists according to the McDonald criteria.

Results

There were 249 (146 female and 103 male) patients with a confirmed MS diagnosis, at a female-to-male ratio of 1.4. The mean age at onset of MS was 37.4 years for the 249 patients with MS and, on the prevalence day, 42.7 years. The most frequent location of clinical MS lesions in the central nervous system was the spinal cord (61%), followed by the cerebrum (55%) and optic nerves (41%). Nearly all (96%) of the patients with MS had been examined by magnetic resonance imaging, and 226 (94%) patients of those examined were suggestive of MS. No family history of MS was found in any of the patients. Most (86%) of the patients had no or mild disability on the prevalence day (31 December 2004). Almost all (96%) patients with MS had been treated with corticosteroids.

Conclusion

Clinical features of patients with MS are described based on the information from the largest case series reported among Chinese. Comparisons and discussions are made with findings from the other populations.

Cesium-filled single wall carbon nanotubes as conducting nanowires: scanning tunneling spectroscopy study

Metal-filled single wall carbon nanotubes (SWCNTs) are examined for possible application to conducting wires in nanoelectronics architecture. The local electronic structure of SWCNTs partially filled with cesium atoms is studied with scanning tunneling spectroscopy. The conduction and valence bands are shifted downward with two localized states in the gap at the location where the Cs atoms are filled. From a first-principles calculation, we confirm that these two gap states are bound states originating from the two lowest conduction bands.

Self-seeded multiwavelength Brillouin-erbium fiber laser

We propose and demonstrate a self-seeded multiwavelength Brillouin-erbium fiber laser with an internally self-excited Brillouin pump, which is achieved by incorporation of a length of single-mode fiber together with a Sagnac loop mirror into a fiber ring cavity. In this simple scheme the Brillouin pump is self-excited in the fiber ring cavity and then used to seed the Brillouin multiwavelength comb in the single-mode fiber. Stable generation of more than 120 Brillouin Stokes wavelengths with relatively uniform amplitudes is demonstrated with this scheme. It is also shown that such a self-seeded Brillouin laser has good stability and repeatability.

MUC1 expression in primary and metastatic pancreatic cancer cells for in vitro treatment by (213)Bi-C595 radioimmunoconjugate

Control of micrometastatic pancreatic cancer remains a major objective in pancreatic cancer treatment. The overexpression of MUC1 mucin plays an important role in cancer metastasis. The aim of this study was to detect the expression of MUC1 in human primary tumour tissues and three pancreatic cancer cell lines (CAPAN-1, CFPAC-1 and PANC-1), and target MUC1-positive cancer cells in vitro using ²¹³Bi-C595 alpha-immunoconjugate (AIC). The expression of MUC1 on pancreatic tumour tissues and cancer cell lines was performed by immunohistochemistry and further confirmed by confocal microscope and flow cytometry analysis on the cell surface. Cytotoxicity of ²¹³Bi-C595 was tested by MTS assay. Apoptosis was documented using TUNEL assay. Overexpression of MUC1 was found in ∼90% of tested tumour samples and the three pancreatic cancer cell lines. ²¹³Bi-C595 is specifically cytotoxic to pancreatic cancer cells in a concentration-dependent fashion. These results suggest that overexpression of MUC1 in pancreatic cancer is a useful target, and that the novel ²¹³Bi-C595 AIC selectively targets pancreatic cancer cells in vitro. ²¹³Bi-C595 may be a useful agent for the treatment of micrometastases or minimal residual disease (MRD) in pancreatic cancer patients with overexpression of MUC1 antigen.

Changes in mortality after the recent economic crisis in South Korea

PURPOSE

To examine the changes in all cause mortality and cause-specific mortality after the economic crisis in South Korea.

METHODS

Monthly mortality data for an entire country was used and intervention analysis applied to compare mortality after the crisis with mortality which would have occurred if the trends before the crisis had continued.

RESULTS

All cause mortality began to increase about 1 year after the crisis, while cardiovascular increased immediately. Transport accidents decreased significantly during the year following the crisis and then regressed towards the pre-economic crisis level. Suicides increased rapidly and maintained an upward trend but subsequently reduced towards the pre-economic crisis level.

CONCLUSIONS

This study has shown an evidence of a relationship between economic crisis and mortality.

Long-term evaluation of mice model infected with Helicobacter pylori: focus on gastric pathology including gastric cancer

BACKGROUND

Long-term evaluation of gastric pathology after H. pylori infection is very important in order to reveal its clinical implications, since debate still exists on the gastric carcinogenesis provoked by H. pylori infection in animal models.

AIM

Either to evaluate the long-term outcome of H. pylori infection or to determine how H. pylori could provoke gastric cancer in the mice model.

METHODS

Four-week-old specific pathogen free C57BL/6 mice (n = 115) were infected with SS1, the mouse-adapted H. pylori strain. After 4, 8, 16, 24, 36, 50 and 80 weeks of bacterial infection, the H. pylori-infected mice were sacrificed.

RESULTS

After 80 weeks of infection, almost all the H. pylori-infected mice developed hyperplastic gastritis, but did not show any evidence of gastric adenoma, dysplasia or carcinoma. PCNA positive cells were most abundant after 50 weeks and tended to decrease thereafter up to 80 weeks, whereas apoptosis began to be noted 8 weeks after H. pylori infection, showing 7-8 apoptotic cells/high power field, and tending to increase as time passed. Normally observed neutral mucin decreased during the experiment, showing the most marked decrease 50 weeks after H. pylori infection. In contrast, acidic mucin was noted from 50 weeks after infection.

CONCLUSION

The SS1-infected mouse seems to be a suitable animal model for H. pylori-related research, and H. pylori itself does not induce gastric cancer in normal wild-type mouse model following long-term exposure, which could be explained by the balance that exists between cell proliferation and apoptosis.

Changes in morbidity and medical care utilization after the recent economic crisis in the Republic of Korea

OBJECTIVE

To examine and quantify the impact of the recent economic crisis on morbidity and medical care utilization in the Republic of Korea.

METHODS

22 675 people from 6791 households and 43 682 people from 12 283 households were questioned for two nationwide surveys that took place in 1995 and 1998, respectively. A separate sample pretest-posttest design was used and we conducted c2 test and logistic regression analysis after controlling for the maturation effect of the morbidity and medical care utilization.

FINDINGS

The morbidity rates of chronic disease and acute disease increased significantly by 27.1% and 9.5%, respectively, whereas the utilization rates of outpatient and inpatient services decreased by 15.1% and 5.2%, respectively. In particular, the pace of decline in the utilization rate of outpatient services varied depending on the type of disease: morbidity rates for mental and behavioural disorders were 13.7%; for cardiovascular disease, 7.1%; and for injury, 31.6%.

CONCLUSION

After the Republic of Korean economic crisis, the morbidity and medical care utilization rates changed significantly but the degree of change depended on the type of disease or service. The time-dependent relationship between the national economy and the morbidity and medical care utilization rates needs to be further investigated.

Physicochemical characterization of UASB sludge with different size distributions

Upflow anaerobic sludge blanket (UASB) sludges developed in UASB system are used to treat various wastewaters. Methanogenic microbial consortia in UASB sludges convert organic compounds to methane under anaerobic conditions. Sludge granules are developed by self-granulation of microorganisms and dynamic balance between granule growth and decay results in coexistence of UASB sludges with different sizes in the reactor. In this study, UASB sludges taken from a laboratory-scale UASB reactor were classified into 4 groups based on their diameters and their physicochemical characteristics were investigated. Each group was analyzed for settling ability, specific methanogenic activity (SMA), and elemental content. Settling ability was proportional to diameter of UASB sludges, suggesting effective detainment of larger granular sludges in the reactor. When acetate o r glucose was used as a substrate, a ll groups showed a relatively slight difference in SMA. However SMA with a volatile fatty acid mixture showed a significant increase with sludge diameter, suggesting better establishment of syntrophic relationship in larger granular sludges. Larger granular sludges showed a higher value of SMA upon environmental changes(ie., pH, temperature, or toxicant concentration). Comparative analysis of elemental contents showed that content (dry weight %) of most tested elements (Fe, Ca, P, Zn, Ni, and Mn) decreased with sludge diameter, suggesting that the elements could be important for initial granulation. Taken together, this study verified experimentally that physicochemical properties of UASB sludges are related to UASB sludge size distributions. Overall results of physicochemical characterization supports that larger granular sludges are better applicable to UASB systems.

[Development of a gas chromatographic column system for the on-line analysis of trace tetrahydrofuran in hexane]

A gas chromatographic system using home-made 7 microns thick cross-linked dimethylpolysiloxane columns for the on-line analysis of trace tetrahydrofuran in hexane in a rubber production facility was developed. The experimental parameters of the column system, including the temperature, flow rate as well as the back-flushing and heart-cutting program were investigated. The total column-switching program was suggested. The system has been successfully operated for more than one year with good resolution, stability and precision (RSD < 5%) in analyzing trace tetrahydrofuran (0-250 x 10(-6), V/V) for industrial process control in the rubber production facility.