Controllable scattering of a single photon inside a one-dimensional coupled resonator waveguide with second-order nonlinearity.

We note that most of the studies of the single photon scattering inside a one-dimensional coupled resonator waveguide are based on the waveguide coupling with the atom systems. In this paper, we will study the single photon scattering enabled by another system, i.e., the second-order nonlinearity, which can act as a single photon switch to control the single photon transmission and reflection inside the one-dimensional coupled resonator waveguide. The transmission rate is calculated to analyze the single-photon scattering properties. In addition, a more complicated second-order nonlinear form, i.e., three-wave mixing, is discussed to control single photon transmission inside the one-dimensional coupled resonator waveguide.

[Effects of chrysin on sphere formation and CK2α expression of ovarian cancer stem-like cells derived from SKOV3 cell line].

OBJECTIVE: To investigate whether inhibitory effect of chrysin on sphere formation of ovarian cancer stem-like cells(spheroids derived from human ovarian cancer SKOV3 cell line ) is involved in the down-regulating of the protein expression of casein kinase CK2α. METHODS: SKOV3-derived ovarian cancer stem-like cells obtained by suspension culture in stem cell-condition medium using ultra-low adhesion plate were treated with various concentrations (5.0, 10.0 and 20.0 µmol/L) of chrysin. Sphere formation assay was used to determine the sphere forming rate of SKOV3-derived ovarian cancer stem-like cells. Western blot was used to analyze the protein expressions of CK2α and cancer stem cell markers CD133 and CD44. Silence of CK2α by siRNA and ectopic expression of CK2α by transfection with pcDNA3.1-CK2α plasmid were used to explore the mechanism underlying the effect of chrysin on sphere formation of SKOV3-derived ovarian cancer stem-like cells. RESULTS: Chrysin (5.0, 10.0 and 20.0 µmol/L) significantly reduced the sphere forming rate of SKOV3-derived ovarian cancer stem-like cells, in a concentration-dependent manner (22.3%±2.5% vs 14.7%±2.1%, 8.6%± 1.7% and 3.8% ± 1.1% respectively; P<0.05). In addition, chrysin (5.0, 10.0 and 20.0 µmol/L) obviously down-regulated the protein expressions of CK2α, CD133 and CD44 in SKOV3-derived ovarian cancer stem-like cells. In combination with CK2α siRNA transfection and chrysin synergistically decreased sphere formation (P<0.05) and the protein expressions of CK2α, CD133 and CD44 in SKOV3-derived ovarian cancer stem-like cells. However, transfection with pcDNA3.1-CK2α plasmid attenuated inhibitory effects of chrysin on sphere formation capability and the expressions of CK2α, CD133 and CD44 of SKOV3-derived ovarian cancer stem-like cells. CONCLUSION: Down-regulation of CK2α protein expression is involved in the inhibition effect of chrysin on the sphere formation capability of SKOV3-derived ovarian cancer stem-like cells.

Assessment of genetic diversity of cucumber cultivars in China based on simple sequence repeats and fruit traits.

The cucumber (Cucumis sativus L.) is an important crop grown worldwide. In this study, the genetic diversity of 42 cucumber cultivars in China was analyzed using 51 pairs of simple sequence repeat (SSR) primers. These primers identified 129 polymorphic loci, 95.6% of which were polymorphic. The mean effective number of alleles, mean Nei's gene diversity, and mean Shannon's information index were 0.36, 0.16, and 0.21, respectively. A cluster analysis demonstrated that the 42 cultivars could be divided into three groups, a result that was largely consistent with those of a principal component analysis (PCA). The PCA indicated that the three groups displayed significant variation in fruit traits. The cultivars of group 1 tended to have longer fruits (>30 cm), longer fruit ends (>4 cm), larger fruit diameters (>5 cm), a sharp strigose fruit spine, and the same fruit end shape. The basal color of the fruit in group 2 was dark green. Group 3 cultivars have no wax or mottling on the fruit surface. Our study demonstrates the value of our SSR primers for assessing genetic diversity in cucumber.

[Analysis of bacterial pathogens and clinical characteristics of children with respiratory tract infections in Tianjin].

Objective: To analyze the pathogenic bacteria and epidemiological characteristics in children with respiratory tract infection in Tianjin area. Methods: Retrospective case analysis was performed on 2 392 hospitalized children in the wards of respiratory diseases, intensive care unit and special care ward of Tianjin Children's Hospital from June 2018 to May 2019. Thirteen pathogenic bacteria in deep sputum and bronchoalveolar lavage fluid samples were detected by loop-mediated isothermal amplification. The laboratory data and clinical characteristics of the infected children were analyzed, and the comparison between groups was performed by t test or χ2 test. Results: Among 2 392 cases, 1 407 were males and 985 females. There was no significant difference in the detection rate between males and females (72.5% (1 020/1 407) vs.74.2% (731/985), χ2=0.87, P=0.35). A total of 1 751 strains and 12 kinds of positive respiratory pathogens were detected, with a detection rate of 73.2%. Among them, 913 (38.2%) strains were Mycoplasma pneumoniae (MP), 514 (21.5%) were Streptococcus pneumoniae (Sp), 381 (15.9%) were Methicillin-resistant Staphylococcus aureus (MRSA) and 279 (11.7%) were Hemophilus influenzae (Hi). There was significant difference in the detection rate of pathogens among different age groups (χ²=83.67, P<0.01). The positive rate of alveolar lavage fluid group was higher than that of deep sputum fluid group [81.6% (614/752) vs. 69.3% (1 137/1 640), χ2=39.89, P<0.01]. The length of hospital stay of children infected with different pathogens was significantly different (all P<0.01). There was significant difference in duration of fever among children infected with different pathogens (χ²=228.69,103.56, 3.96, 27.38,24.50,41.66, all P<0.05). There were 63 (7.7%) cases of atelectasis, 260 (31.9%) cases of pleurisy and 120 (14.7%) cases of pleural effusion in MP children. Children with Sma were most likely to involve the heart system (2/9), and children with Eco infection had a higher incidence of complications such as those of blood (3/19), urinary (2/19), digestive systems(4/19), systemic inflammatory response syndrome and sepsis (1/19). Conclusions: The main bacterial pathogens of respiratory tract infection in children in Tianjin were MP, Sp, MRSA and Hi. It is suggested that clinicians should not only pay attention to the respiratory symptoms of children, but also pay attention to the complications caused by bacterial pathogen infection, so as to prevent the deterioration of the disease and improve the prognosis.

[Hyperglycemia caused by mutation of GCK gene in 10 patients analysis of clinical and mutation characteristics].

Objective: To explore the gene mutation characteristics and detailed clinical presentations of hyperglycemia caused by GCK mutations in 10 patients. Methods: The clinical and follow-up data of 10 patients with hyperglycemia caused by mutation of GCK gene were reviewed. The patients were ascertained between January 1, 2014 and August 31, 2018 at the Department of Pediatrics, the First Affiliated Hospital of Zhejiang University and Ningbo Women & Children's Hospital. Clinical data were collected, including age, gender, main complaint, family history, fasting blood glucose, fasting blood insulin, 2-hour blood glucose, 2-hour blood insulin after oral glucose tolerance test, glycosylated hemoglobin, anti-glutamic acid decarboxylase antibody and body mass index. Mutations of GCK gene were detected by Sanger sequencing or high-throughput sequencing of diabetes-related genes in the patients and their family members. Results: There were ten patients, 8 of them were male, 2 were female.The ages at diagnosis varied between 4.7 to 12.3 years. The patients usually did not have obvious clinical symptoms of diabetes mellitus. Most of them were unexpectedly found to have hyperglycemia and with impaired glucose metabolism in three consecutive generations. The fasting blood glucose of patients was 6.8-7.7 mmol/L, 2-hour postprandial blood glucose was 7.8-11.6 mmol/L. Fasting blood insulin was 0.5-8.5 mU/L, glucose tolerance test results showed that 2 h postprondial blood insulin was 1.3-55.4 mU/L. The level of glycosylated hemoglobin was 6.1%-6.8%. Anti-glutamic acid decarboxylase antibody was negative in all patients. The GCK mutations identified in patients and one of their parents were located at exon5 (4 cases), exon9 (2 cases), exon2 (1 case), exon4 (1 case), exon6 (1 case) and exon7 (1 case). Conclusions: Most of the hyperglycemia patients caused by GCK mutations did not have typical clinical symptoms of diabetes. The fasting blood glucose was slightly elevated. Abnormal glucose tolerance test results were found in all 10 patients. Three consecutive generations of family had impaired glucose metabolism. GCK mutations located at exon 5 were common in 10 cases. There was no correlation between type of mutations and plasma glucose levels in domestic and international researches. When fasting glucose was found abnormal in clinic, a complete family history should be taken and the GCK gene should be sequenced to confirm the diagnosis in time.

[Partial thyroxine binding globulin deficiency in test tube infants: report of cases and literature review].

OBJECTIVE: To investigate the clinical characteristics of twins with thyroxine binding globulin (TBG) deficiency and to find SERPINA7 gene mutations. METHOD: Data(2015) related to clinical characteristics, serum biochemistry, gene mutations and pedigree of two children with TBG deficiency were collected in the First Affiliated Hospital of College of Medicine, Zhejiang University. The related literature was searched form China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform, National Center for Biotechnology Information and PubMed (up to December 2015) by using search terms "Thyroxine binding globulin deficiency, gene, mutation" . RESULT: Both patients were diagnosed as central hypothyroidism at the beginning and treated with L-thyroxine. Both of the identical twins of the triplet were observed for mutation in exon3, c. 631Gï¹¥A(p.A211T), a new mutation had not been reported, but their parents and another non-identical triplet brother were normal. Literature review showed that 23 foreign cases with SERPINA7 gene mutation had been reported, however, no Chinese with SERPINA7 gene mutation had been reported. Among reported cases it was shown that SERPINA7 gene mutations located in exon, intron, promoter and enhancer. Up to now, 49 variants had been identified, 41 of them located in the mutated genes. Including these two cases, patients with thyroxine binding globulin deficiency were characterized by reduced serum TH levels, but normal free TH and TSH and absence of clinical manifestations. CONCLUSION: The new mutation of SERPINA7 gene c. 631Gï¹¥A(p.A211T)is not transmitted via the known X chromosome linked heredity, and as the cases were test tube triplet infants, it is a de novo mutation. The serum thyroid function tests of TBG deficiency showed decreased TT4, TT3 and normal TSH and TBG deficiency is often misdiagnosed as central hypothyroidism.

Influence of Surface Passivation on AlN Barrier Stress and Scattering Mechanism in Ultra-thin AlN/GaN Heterostructure Field-Effect Transistors.

Ultra-thin AlN/GaN heterostructure field-effect transistors (HFETs) with, and without, SiN passivation were fabricated by the same growth and device processes. Based on the measured DC characteristics, including the capacitance-voltage (C-V) and output current-voltage (I-V) curves, the variation of electron mobility with gate bias was found to be quite different for devices with, and without, SiN passivation. Although the AlN barrier layer is ultra thin (c. 3 nm), it was proved that SiN passivation induces no additional tensile stress and has no significant influence on the piezoelectric polarization of the AlN layer using Hall and Raman measurements. The SiN passivation was found to affect the surface properties, thereby increasing the electron density of the two-dimensional electron gas (2DEG) under the access region. The higher electron density in the access region after SiN passivation enhanced the electrostatic screening for the non-uniform distributed polarization charges, meaning that the polarization Coulomb field scattering has a weaker effect on the electron drift mobility in AlN/GaN-based devices.

Hyperhomocysteinemia Is Associated with Vitamin B-12 Deficiency: A Cross-sectional Study in a Rural, Elderly Population of Shanxi China.

OBJECTIVES: To report the association of lifestyle factors and plasma vitamin B-12 with hyperhomocysteinemia in a large sample of men and women living in a region of China where there is an increased risk of NTDs. DESIGN: Community-based, cross-sectional study of Lvliang City, Shanxi Province, China. SETTING: Hyperhomocysteinemia is an independent risk factor for cardiovascular disease (CVD) and a sensitive marker of vitamin B-12 and folate deficiency. PARTICIPANTS: A total of 2355 (1044 men and 1311 women) participants born before 1 January 1958 (≥55 years of age) and living in Lvliang City for at least 2 months a year were included. MEASUREMENTS: The participants were assessed regarding demographic characteristics, height, weight, as well as having a physical examination and blood sampling for serum cholesterol, total homocysteine (tHcy), folate, and vitamin B12 levels. RESULTS: The median (25th-75th percentile) tHcy concentration was 21.5 (15.8-33.6) µmol/L in men and 18.0 (13.4-24.8) µmol/L in women. The overall prevalence of hyperhomocysteinemia (tHcy ≥15 µmol/L) was 72.6% (84.3% in men and 63.2% in women), inversely correlated with folate (r=-0.230, P=0.006) and vitamin B-12 (r=-0.540, P<0.001), and positively correlated with uric acid (r=0.054, P<0.001). Vitamin B-12 and folate deficiency, older age, and male gender were associated with elevated tHcy; with vitamin B-12 deficiency being the strongest. CONCLUSIONS: Plasma tHcy concentration and hyperhomocysteinemia were significantly higher in this population than in previously studied populations. Vitamin B-12 and folate supplementation, concomitant lifestyle changes such as smoking cessation, and lipid-lowering treatments may help to decrease plasma tHcy concentrations and reduce the CVD risk in this population.

Influence and significance of intervening diabetes microRNA expression profile of NOD mice with exendin-4.

OBJECTIVE: To provide selectable microRNA for intervening diabetes mellitus diseases, NOD mice's expression of microRNA in pancreas tissues and blood under the exendin-4 intervention of was observed and the difference of microRNA target gene was screened. MATERIALS AND METHODS: Forty clean NOD mice were randomly divided into four groups (in each group, n = 10): One is blank control group D which is intervened with normal saline, and the other three groups were divided into low-dose group A, middle-dose group B, and high-dose group C according to the different exendin-4 dosage 2, 4, and 8 µg/kg·d. After the 8-week intervention, these four groups were killed, and the pancreatic tissue and blood were left to prepare specimens for morphology and molecular biology analysis. The specimen with differential expression microRNA in pancreas tissue and blood should be screened out after detected with the locked nucleic acid array system (LNATM) microRNA expression profile chip. The primers should be designed, and the ABI7500 real-time fluorescent quantitative PCR should be applied to amplify, analyze, and verify according to the screen results of the microRNA chip in order to screen out the significant differentially expressed microRNA. RESULTS: Histological detection showed that the pancreas of the mice in control group D was fibrosis gradually and the islet frame was relatively disordered and significantly atrophied. Groups A, B, and C have no islet hypertrophy or atrophy and the degree of fibrosis of the pancreas has reduced. According to the gene chip detection, there are four significantly differently expressed microRNAs in pancreas tissue and blood among the group A, B, and C, among which miR-19a, miR-19b, and miR-22 were downregulated expressed while the miRNA-1 was upregulated expressed. Bioinformatics analysis showed that the target genes of 4 differentially regulated microRNA genes were related to cell proliferation, apoptosis, glucose metabolism, and angiogenesis. The expression of microRNA in pancreatic tissue and blood of NOD rats was highly consistent. CONCLUSIONS: MicroRNA expression file of pancreatic tissue and blood can be changed during the intervention of the NOD rat model with exendin-4. MicroRNA that indicates the differential expression may take part in the recovering process of the NOD pancreatic trauma. At the same time, the administration of exendin-4 can protect NOD mice, reduce its pancreatic tissue fibrosis, and regulate molecular markers of pancreatic cells in size and pancreatic mast cells. This may be one of the main mechanisms of pancreatic injury in diabetes prevention.

Gene delivery in tissue engineering and regenerative medicine.

As a promising strategy to aid or replace tissue/organ transplantation, gene delivery has been used for regenerative medicine applications to create or restore normal function at the cell and tissue levels. Gene delivery has been successfully performed ex vivo and in vivo in these applications. Excellent proliferation capabilities and differentiation potentials render certain cells as excellent candidates for ex vivo gene delivery for regenerative medicine applications, which is why multipotent and pluripotent cells have been intensely studied in this vein. In this review, gene delivery is discussed in detail, along with its applications to tissue engineering and regenerative medicine. A definition of a stem cell is compared to a definition of a stem property, and both provide the foundation for an in-depth look at gene delivery investigations from a germ lineage angle.

Nutritional status of the elderly in rural North China: a cross-sectional study.

OBJECTIVES: This study aimed to describe the nutritional status of elderly people living in a rural area of North China. DESIGN: Community-based, cross-sectional prevalence survey. SETTING: 3 rural towns of Lvliang City, Shanxi Province, China. PARTICIPANTS: A sample of 1845 community residents (29.1% of those eligible) 55 years or older (birth before 1958-01-01). MEASUREMENTS: The participants were assessed regarding demographic characteristics, height, weight, as well as having a physical examination and blood sampling for serum cholesterol, total homocysteine (tHcy), folate, and vitamin B12 levels. RESULTS: 991 (53.7%) were female and 139 (7.5%) did not complete the anthropometric measurement. Prevalence of underweight and obesity was 3.5% and 24.9% in men and 6.7% and 31.0% in women (P = 0.003, P = 0.005, respectively). Prevalence of hypercholesterolemia and hypocholesterolemia was 13.5% and 52.6% in men and 25.0% and 34.3% in women (P < 0.001, P < 0.001, respectively). Prevalence of high LDL-c concentrations was 8.8% in men and 16.8% in women (P < 0.001). The mean serum tHcy in men (28.8 ± 20.1 µmmol/l) was significantly higher than in women (21.0 ± 15.1 µmmol/L, P < 0.001). Prevalence of hyperhomocysteinemia (defined as > 15µmmol/L) was 79.7% in men and 65.5% in women (P < 0.001). Prevalence of low folate (defined as < 11 nmol/L) and vitamin B12 levels (defiend as < 185 pmol/L) was 70.8 % and 76.8% in men and 56.5% and 72.6% in women (P < 0.001, P = 0.036, respectively). Correlation coefficients between tHcy, folate, and vitamin B12 indicated an inverse linear correlation (r = -0.21, P < 0.001, r = -0.35, P < 0.001, respectively). CONCLUSIONS: As China's economic climate has developed, the nutritional status of elderly people in the rural parts of the country has improved in some aspects. However, the trend toward obesity will lead to a shift in the burden of obesity-related chronic diseases. In addition, rurally-located elderly people are at high risk of death that may be associated with abnormal serum cholesterol. The data also suggest that severe deficiencies in folate and vitamin B12 levels exist, as well as there being a high prevalence of hyperhomocysteinemia. Folate and vitamin B12 supplementation are necessary to prevent related diseases.