[Prognostic analysis of children with Philadelphia chromosome-like acute lymphoblastic leukemia common genes].

Objective: To summarize the clinical data and prognosis of children with Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) common genes. Methods: This was a retrospective cohort study.Clinical data of 56 children with Ph-like ALL common gene cases (Ph-like ALL positive group) treated from January 2017 to January 2022 in the First Affiliated Hospital of Zhengzhou University, Henan Children's Hospital, Henan Cancer's Hospital and Henan Provincial People's Hospital were collected, 69 children with other high-risk B cell acute lymphoblastic leukemia (B-ALL) at the same time and the same age were selected as the negative group. The clinical characteristics and prognosis of two groups were analyzed retrospectively. Comparisons between groups were performed using Mann-Whitney U test and χ2 test. Kaplan-Meier method was used for survival curve, Log-Rank test was used for univariate analysis, and the Cox regression model was used for multivariate prognosis analysis. Results: Among 56 Ph-like ALL positive patients, there were 30 males and 26 females, and 15 cases were over 10 years old. There were 69 patients in Ph-like ALL negative group. Compared with the negative group, the children in positive group were older (6.4 (4.2, 11.2) vs. 4.7 (2.8, 8.4) years), and hyperleukocytosis (≥50×109/L) was more common (25% (14/56) vs. 9% (6/69)), the differences were statistically significant (both P<0.05). In the Ph-like ALL positive group, 32 cases were positive for IK6 (1 case was co-expressed with IK6 and EBF1-PDGFRB), 24 cases were IK6-negative, of which 9 cases were CRLF2 positive (including 2 cases with P2RY8-CRLF2, 7 cases with CRLF2 high expression), 5 cases were PDGFRB rearrangement, 4 cases were ABL1 rearrangement, 4 cases were JAK2 rearrangement, 1 case was ABL2 rearrangement and 1 case was EPOR rearrangement. The follow-up time of Ph-like ALL positive group was 22 (12, 40) months, and 32 (20, 45) months for negative group. The 3-year overall survival (OS) rate of positive group was significantly lower than the negative group ((72±7) % vs. (86±5) %, χ2=4.59, P<0.05). Compared with the 24 IK6-negative patients, the 3-year event free survival (EFS) rate of 32 IK6 positive patients was higher, the difference was statistically significant ((88±9) % vs. (65±14) %, χ2=5.37, P<0.05). Multivariate Cox regression analysis showed that the bone marrow minimal residual disease (MRD) not turning negative at the end of first induction (HR=4.12, 95%CI 1.13-15.03) independent prognostic risk factor for patient with Ph-like ALL common genes. Conclusions: Children with Ph-like ALL common genes were older than other high-risk B-ALL patients at diagnosis, with high white blood cells and lower survival rate. The bone marrow MRD not turning negative at the end of first induction were independent prognostic risk factor for children with Ph-like ALL common gene.

[Efficacy and safety of catheter ablation in patients with new-onset atrial arrhythmia after surgical excision of left atrial myxoma].

Objective: To evaluate the safety and efficacy of catheter ablation in patients with new-onset atrial arrhythmia after surgical excision of left atrial myxoma. Methods: Nine patients with new onset atrial arrhythmia and a prior history of left atrial myxoma, who received surgical myxoma excision and catheter ablation between September 2014 and November 2019, were included in the present study. Baseline characteristics, procedural parameters during catheter ablation, severe perioperative adverse events, recurrence rate of arrhythmia and clinical prognosis were analyzed. Kaplan Meier survival analysis was used to define the maintenance rate of sinus rhythm after catheter ablation in this patient cohort. Results: Nine patients were included. The average age was (55.8 ± 9.1) years old (3 male), there were 3 patients (3/9) with paroxysmal atrial fibrillation (PAF) and 6 patients (6/9) with atrial flutter or atrial tachycardia (AFL or AT). Ablation was successful in all patients, there were no perioperative complications such as stroke, pericardial effusion, cardiac tamponade, vascular complications or massive hemorrhage. During a mean follow-up time of 40.0 (27.5, 55.5) months, sinus rhythm was maintained in six patients (6/9) after the initial catheter ablation. The overall sinus rhythm maintenance rate was 2/3. In addition, 1 out of the 3 AF patients (1/3) developed recurrence of AF at 3 month after ablation, and 2 out of the 6 AFL or AT patients (2/6) developed late recurrence of AF or AFL (19 months and 29 months after ablation), two out of three patients with recurrent AFs or AFL received repeated catheter ablation and one patient remained sinus rhythm post repeat ablation. Meanwhile, there was no recurrence of atrial myxoma, no death, stroke, acute myocardial infarction and other events during the entire follow-up period. Conclusions: Catheter ablation is a safe and feasible therapeutic option for patients with new-onset atrial arrhythmia after surgical excision of left atrial myxoma.

[The thromboembolism risk of low-risk atrial fibrillation patients with different clinical characteristics].

Objective: This study explored the thromboembolism risk of low-risk atrial fibrillation (AF) patients (CHA2DS2-VASc score of 0 or 1 for male and 1 or 2 for female) with different clinical characteristics to provide the basis for anticoagulation decision-making in these patients. Methods: We prospectively enrolled consecutive 2 862 nonvalvular low-risk AF patients between August 2011 to December 2018 in China-AF (China Atrial Fibrillation Registry) Study, their CHA2DS2-VASc score was 0 or 1 for male and 1 or 2 for female. According to their age, sex, presence or absence of hypertension, diabetes mellitus, congestive heart failure, and vascular disease at the time of enrolling, patients were divided into CHA2DS2-VASc score 0 score group, 1 score group, and 2 score group. Patients were followed up every 6 months by outpatient clinic visit or telephone interview. The outcome was a thromboembolic event, including ischemic stroke and systemic embolism. Univariate Cox regression analysis was used to compare the thromboembolism risk between the patients with different risk factors and CHA2DS2-VASc score 0 group. Results: A total of 2 862 low-risk atrial fibrillation patients were enrolled in this study. 915 patients (32.0%) were female, and age was (55.0±10.7) years old. There were 933 patients (32.6%) in CHA2DS2-VASc score 0 group, 1 401 patients (49.0%) in score 1 group and 528 patients (18.5%) in score 2 group. During follow-up (median 1.5 years, 5 811.82 person-years), 33 cases of thromboembolic events were recorded, the annual rate of thromboembolism was 0.57% (95%CI 0.40%~0.80%). The number of thromboembolic events in patients with CHA2DS2-VASc score 0, 1 and 2 were 8, 11 and 14, respectively, and the annual thromboembolism event rates were 0.40% (95%CI 0.20%-0.81%), 0.39% (95%CI 0.22%-0.71%) and 1.34% (95%CI 0.80%-2.27%), respectively. The risk of thromboembolism of CHA2DS2-VASc score 2 group (HR=3.53, 95%CI 1.48-8.44; P=0.005), especially female patients aged 65-74 years in CHA2DS2-VASc score 2 group (HR=2.67, 95%CI 1.63-4.38; P<0.000) was significantly higher than that in patients of CHA2DS2-VASc score 0 group. Conclusion: Low-Risk Atrial Fibrillation patients with CHA2DS2-VASc score 2, especially female patients aged 65-74 years old with CHA2DS2-VASc score 2 are at higher risk of thromboembolism in low-risk AF patients. For such patients, intensified oral anticoagulant therapy might be helpful to reduce the risk of thrombolism.

Lipoxin A4 alleviates lung injury in sepsis rats through p38/MAPK signaling pathway.

The aim of the study was to explore the effect of lipoxin A4 (LXA4) on lung injury in sepsis rats through the p38/mitogen-activated protein kinase (MAPK) signaling pathway. Sprague-Dawley rats were used for the study. The rat model of sepsis-induced acute lung injury was established via cecal ligation (Sepsis group, n=20). LXA4 (0.1 mg/kg) was injected at 6 h after modeling (Treatment group, n=20), and a The Control group (n=20) was also set up. The 7-day survival rate was 100% in The Control group, and LXA4 raised the survival rate of rats in the Sepsis group from 40% to 60% (P<0.01). Alveolar fluid clearance (AFC) significantly declined and the wet/dry weight (W/D) ratio of lung tissues rose remarkably in the Sepsis group compared with those in the Control group, while LXA4 restored AFC and reduced the W/D ratio of lung tissues (P<0.05), suggesting that LXA4 treatment reduces lung fluids and partially enhances AFC, thus lowering the W/D ratio of lung. The total cell count, polymorphonuclear neutrophils (PMN) percentage and concentration of tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 in bronchoalveolar lavage fluid (BALF) were obviously increased in the Sepsis group compared with those in the Control group, while they were markedly decreased in the Treatment group (P<0.05). The activity of myeloperoxidase (MPO) in lung tissue homogenate was evidently higher in the Sepsis group than that in The Control group, while it was notably lower in the Treatment group than that in the Sepsis group after LXA4 treatment (P<0.05). Moreover, it was observed microscopically that the morphology of lung tissues was intact in the Control group. Finally, the results of Western blotting manifested that the p-p38/ MAPK protein expression was remarkably increased in the Sepsis group, indicating the activation of the p38/MAPK pathway, while it was remarkably decreased in the Treatment group, indicating the inhibited activity of the pathway (P<0.05). LXA4 has an anti-inflammatory effect on sepsis rats with lung injury, and such effect is related to the p38/MAPK signaling pathway.

MiR-135a inhibitor alleviates pulmonary arterial hypertension through ß-Catenin/GSK-3ß signaling pathway.

OBJECTIVE: The aim of this study was to investigate the regulatory role of micro-ribonucleic acid (miR)-135a in monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH) in rats, and to analyze the possible regulatory mechanism. MATERIALS AND METHODS: A total of 30 Sprague-Dawley rats were randomly divided into three groups, including the blank control group, model group and miR-135a inhibitor intervention group. The right ventricular systolic pressure (RVSP) and right ventricle hypertrophy index (RVHI) were measured in rats of each group. Hematoxylin and eosin (HE) staining was adopted to detect the pathological changes in lung tissues of rats. Enzyme-linked immunosorbent assay (ELISA) was performed to measure the levels of interleukin-6 (IL-6) and IL-1ß in lung tissues. Meanwhile, the messenger RNA (mRNA) and protein levels of ß-catenin and glycogen synthase kinase-3ß (GSK-3ß) in lung tissues of rats were determined via Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and Western blotting assay, respectively. RESULTS: Compared with the blank control group, RVSP and RVHI increased significantly in the model group. The pathological morphology of the lung tissues was poor, and the content of IL-6 and IL-1ß was markedly up-regulated in the model group. Meanwhile, the mRNA and protein levels of ß-catenin and GSK-3ß were notably elevated in the model group than the blank control group. In the miR-135a inhibitor intervention group, RVSP and RVHI decreased significantly, and the pathological morphology of lung tissues was evidently improved when compared with the blank control group. Furthermore, the content of IL-6 and IL-1ß was remarkably reduced, and the mRNA and protein levels of ß-catenin and GSK-3ß were significantly declined in the miR-135a inhibitor intervention group. CONCLUSIONS: MiR-135a inhibitor significantly alleviates inflammatory response in the lung tissues and ameliorates damage to the pathological morphology. The possible underlying mechanism may be associated with the ß-catenin/GSK-3ß signaling pathway.

[Association between weight control and recurrence of atrial fibrillation after catheter ablation in overweight and obese patients].

Objectives: This study explored the relationship between weight control and atrial fibrillation (AF) recurrence after catheter ablation in overweight and obese patients. Methods: We prospectively enrolled consecutive 333 overweight and obese patients aged 28 to 87 years old, who underwent catheter ablation for AF in Beijing Anzhen Hospital between October 2015 and February 2016. Data of patients' characteristics, laboratory examination and treatment were collected at baseline. Each patient was followed up at 3, 6 and 12 months after ablation to collect information on weight, AF recurrence, stroke, major bleeding, hospitalization for cardiovascular reasons and death, etc. Patients were divided into weight controlled group (ΔBMI<-1 kg/m(2)) and weight uncontrolled group (ΔBMI≥-1 kg/m(2)), according to the changes in the most recent exposure BMI before AF recurrence in patients with recurrence or the BMI at 12 months' follow-up in patients without recurrence and the BMI at baseline. Multivariate logistic regression was performed to adjust other known risk factors of AF recurrence and to explore the association between weight control and AF recurrence after catheter ablation. Results: There were 54 patients in weight controlled group and 279 patients in weight uncontrolled group. There were no significant differences in age, gender, education level, left atrial size and history of hypertension between the two groups (all P>0.05). The proportion of patients using angiotensin-converting enzyme inhibitors/angiotensin receptor blockers was higher in the weight controlled group (50.0%(27/54) vs. 34.8%(97/279), P=0.034). However, there was no significant difference in the proportion of patients with obesity (33.3% (18/54) vs. 29.7% (83/279)), paroxysmal AF (59.3% (32/54) vs. 56.6% (158/279)) and AF duration less than 5 years (76.9% (40/52) vs. 65.4% (178/272)) between the weight controlled group and the uncontrolled group. During 1-year follow-up after ablation, the recurrence rate of AF was significantly lower in the weight controlled group than that in the weight uncontrolled group (14.8% (8/54) vs. 32.6%(91/279), P=0.009). Multivariable logistic regression analysis shows that weight control is independently associated with a lower postoperative AF recurrence rate (OR=0.40, 95%CI 0.18-0.90, P=0.026). Conclusion: Weight control is strongly associated with a lower AF recurrence rate after catheter ablation in overweight and obese patients.

CT measurement and analysis of the target vertebral body in elderly patients with uncompressed osteoporotic thoracolumbar fractures.

OBJECTIVE: To evaluate the feasibility of determining the target vertebral body (TV) of uncompressed elderly osteoporotic thoracolumbar fractures through measuring Hounsfield unit (HU) value. PATIENTS AND METHODS: Elderly patients with osteoporotic thoracolumbar fractures aged above 65 years old hospitalized from 2015 to 2016 were retrospectively analyzed. The cases whose TV could not be determined by computed tomography (CT) imaging but confirmed by magnetic resonance imaging (MRI) were selected. The mean HU values of the trabecular bone regions of TV and adjacent vertebral body in the multi-detector CT (MDCT) sagittal three-dimensional reconstructed image were measured and compared. At the same time, 60 thoracolumbar adjacent vertebral bodies without fractures were selected from 20 people, and the mean HU value of the trabecular bone region of each vertebra in the MDCT sagittal three-dimensional reconstructed image was measured and compared. RESULTS: There were correlations among the mean HU values of 60 thoracolumbar adjacent vertebral bodies in the 20 people without fractures, and there were no differences in the correlations between middle vertebral body (MV) and upper vertebral body (UV) and between MV and lower vertebral body (LV) compared with the correlation between UV and LV. In the 31 fracture cases, the mean HU values had correlations among TV, UV and LV, there was no difference in the comparison of correlations between TV and UV and between TV and LV, but the correlations between TV and UV and between TV and LV had differences compared with the correlation between UV and LV. CONCLUSIONS: The mean HU value of TV of uncompressed elderly osteoporotic thoracolumbar fractures is increased abnormally compared with that of the adjacent vertebral body, and it is feasible to determine the TV of uncompressed osteoporotic thoracolumbar fractures according to the mean HU value.

Safety of catheter ablation for atrial fibrillation in patients with intracranial hemorrhage.

BACKGROUND: The safety of anticoagulation and radiofrequency catheter ablation (RFCA) in patients with atrial fibrillation (AF) and a history of intracranial hemorrhage (ICH) remains unclear. We investigated the risks and benefits of this approach in AF patients with a history of ICH. PATIENTS AND METHODS: The ICH group included 45 AF patients with a history of ICH who underwent RFCA. Five of these patients were excluded because ICH occurred spontaneously after cerebral infarction. The control group included 80 individuals who presented for AF ablation and did not have a history of ICH. Two controls were matched for each study group patient in terms of sex, age (±2 years), type of AF, and procedure date. RESULTS: Patients in the ICH group had higher CHADS2 (1.7 ± 1.3 vs. 1.1 ± 1.2, p < 0.05), CHA2DS2-VASc (2.6 ± 1.7 vs. 1.9 ± 1.6, p < 0.05), and HAS-BLED scores (2.5 ± 1.0 vs. 1.1 ± 1.0, p < 0.001). All participants in both groups underwent successful RFCA. The incidence of ICH during follow-up (1 vs. 0, p = 0.333) was similar between the ICH and control groups. AF-free survival between the two groups was not significant (log-rank p = 0.283) within the first 3 months, but was significant (log-rank p = 0.011) within 48 months of RFCA. History of ICH was the only independent predictor of AF recurrence according to univariate Cox regression analysis. CONCLUSION: In AF patients with a history of ICH, AF ablation with a standard anticoagulation strategy is safe and does not seem to be associated with an increased risk of hemorrhage.

A comparative, cross-species investigation of the properties and roles of transferrin- and lactoferrin-binding protein B from pathogenic bacteria.

Pathogenic bacteria from the families Neisseriaeceae and Moraxellaceae acquire iron from their host using surface receptors that have the ability to hijack iron from the iron-sequestering host proteins transferrin (Tf) and lactoferrin (Lf). The process of acquiring iron from Tf has been well-characterized, including the role of the surface lipoprotein transferrin-binding protein B (TbpB). In contrast, the only well-defined role for the homologue, LbpB, is in its protection against cationic antimicrobial peptides, which is mediated by regions present in some LbpBs that are highly enriched in glutamic or aspartic acid. In this study we compare the Tf-TbpB and the Lf-LbpB interactions and examine the protective effect of LbpB against extracts from human and transgenic mouse neutrophils to gains insights into the physiological roles of LbpB. The results indicate that in contrast to the Tf-TbpB interaction, Lf-LbpB interaction is sensitive to pH and varies between species. In addition, the results with transgenic mouse neutrophils raise the question of whether there is species specificity in the cleavage of Lf to generate cationic antimicrobial peptides or differences in the potency of peptides derived from mouse and human Lf.

[Role of hypoxia-inducible factor in the pathogenesis of rheumatoid arthritis].

Rheumatoid arthritis (RA) is a destructive chronic autoimmune disease characterized by synovium inflammation, cartilage destruction, bone erosion and the presence of autoantibodies. Hypoxia is a prominent micro-environmental feature in a range of disorders including RA. A combination of increased oxygen consumptionby inflamed resident cells and infiltrating immune cells along with a disrupted blood supply due to vascular dysfunction contribute to tissue hypoxia in RA. Hypoxia in turn regulates a number of key signaling pathways that help adaptation. The primary signaling pathway activated by hypoxia is the hypoxia-inducible factor (HIF) pathway. It has been shown that HIFs are highly expressed in the synovium of RA. HIFs mediate the pathogenesis of RA through inducing inflammation, angiogenesis, cell migration, and cartilage destruction, and inhibiting the apoptosis of synovial cells and inflammatory cells. HIF expressed in RA can be regulated in both oxygen-dependent and independent fashions, like inflammatory cytokines, leading to the aggravation of this disease. Considering the vital role of HIF in the pathogenesis of RA, we reviewed the new advances about hypoxia and RA. In this review, we firstly discussed the hypoxia-inducible factor and its regulation, and then, the pathologic role of hypoxia in RA, mainly elucidating the role of hypoxia in synovitis and cartilage destruction and immune cells. Finally, we provided evidence about the potential therapeutic target for treating RA.

HbA1c levels as predictors of ablation outcome in type 2 diabetes mellitus and paroxysmal atrial fibrillation.

AIMS: The aim of this study was to evaluate whether the levels of HbA1c could predict the outcome of ablation in patients with type 2 diabetes mellitus (T2DM) and paroxysmal atrial fibrillation (PAF). PATIENTS AND METHODS: The study comprised 149 consecutive patients with T2DM and PAF who underwent their first circumferential pulmonary vein isolation. HbA1c levels were measured before ablation. Cox proportional hazards models were constructed to assess the relationship between HbA1c levels and the recurrence of atrial fibrillation (AF). RESULTS: Of the 149 patients, 60 (40.3 %) developed AF recurrence after a median 12-month follow-up. Multivariate Cox regression analysis revealed that left atrium size and HbA1c were independent predictors of recurrent atrial tachyarrhythmia. Receiver operating characteristic analysis demonstrated that an HbA1c cut-off value of ≥ 6.9 % predicted recurrence with 55.0 % sensitivity and 67.4 % specificity (AUC = 0.634). The success rate of ablation was 69.0 % in patients with an HbA1c value of < 6.9 % compared with 46.8 % in those with an HbA1c value of ≥ 6.9 % (log-rank test, p = 0.004). CONCLUSION: High levels of HbA1c were associated with an increased risk of recurrence of atrial tachyarrhythmia in patients with T2DM and PAF undergoing catheter ablation.

Four pairs of gene-gene interactions associated with increased risk for type 2 diabetes (CDKN2BAS-KCNJ11), obesity (SLC2A9-IGF2BP2, FTO-APOA5), and hypertension (MC4R-IGF2BP2) in Chinese women.

Metabolic disorders including type 2 diabetes, obesity and hypertension have growing prevalence globally every year. Genome-wide association studies have successfully identified many genetic markers associated to these diseases, but few studied their interaction effects. In this study, twenty candidate SNPs from sixteen genes are selected, and a lasso-multiple regression approach is implemented to consider the SNP-SNP interactions among them in an Asian population. It is found out that the main effects of the markers are weak but the interactions among the candidates showed a significant association to diseases. SNPs from genes CDKN2BAS and KCNJ11 are significantly associated to risk for developing diabetes, and SNPs from FTO and APOA5 might interact to play an important role for the onset of hypertension.

Recurrent hospitalisation with pneumonia is associated with higher 1-year mortality in frail older people.

BACKGROUND: Previous studies persistently showed that functional dependence was associated with higher long-term (≥1 year) mortality of older patients hospitalised with community-acquired pneumonia (CAP). The importance of other factors was, however, not well reported. AIM: This study aimed to investigate the relative contributions of comorbidity, nutritional status and frailty to 1-year mortality. METHODS: We prospectively recruited older patients, aged ≥65 years, hospitalised with CAP from October 2009 to September 2010 at the Prince of Wales Hospital, Hong Kong. Demographics, Charlson's Comorbidity Index, mid-arm circumference (MAC) and Clinical Frailty Scale (CFS) were recorded as baseline characteristics. The severity of pneumonia was evaluated by the CURB score (confusion, blood urea nitrogen, respiratory rate and low blood pressure). The surviving patients were followed for 1 year since discharge to monitor readmission for CAP and all-cause mortality. We entered the following variables into the multivariate Cox regression model to identify independent predictors of 1-year all-cause mortality: age, sex, residential status, MAC, Charlson's Comorbidity Index, CFS and readmission for CAP. RESULTS: The final cohort consisted of 428 patients who were discharged from hospital. Within 1 year after hospital discharge, all-cause mortality and readmission for CAP were 22.4% and 32.0% respectively. Independent predictors of 1-year mortality were male sex (hazard ratio (HR) = 1.57, 95% confidence interval (CI) = 1.02-2.48), severe under-nutrition (MAC ≤21 cm) (HR = 3.75, 95% CI = 1.66-8.46), frailty (CFS ≥5) (HR = 2.36, 95% CI = 1.29-4.27) and readmission for CAP (HR = 4.50, 95% CI = 2.82-7.17). CONCLUSIONS: Recurrent pneumonia may be a terminal life event of frail older people so that advance care planning should be considered in those with recurrent admission for pneumonia.

Effect of high magnetic field on structure and oxygen adsorption of CuO films.

CuO films have been fabricated by a two-step method: depositing Cu films on single crystal Si substrates by magnetron sputtering; thermal oxidation of the as-deposited Cu films in the air at 600 degrees C. To investigate the effect of magnetic field on CuO film growth, a series of static fields are added along the substrate in the oxidation process. Field emission scanning electron microscopy shows that the high magnetic field promotes the densification and the grain refinement of the films. The X-ray diffraction results reveal that the films have monoclinic structure of CuO. The relative intensity of (111) peak strengthens gradually with increasing the magnetic field intensity, implying that the magnetic field facilitates the growth along [111] direction. X-ray photoelectron spectra of Cu 2p core-level indicate that +2 is the main valence state for Cu ions in CuO films, and the magnetic field produces deeper oxidation of the samples. The high binding energy part of O 1s XPS spectra, which reflects the oxygen adsorption ability, shrinks at low magnetic field, and then expands with the further increase of the magnetic field. The mediation of oxygen adsorption is related to the improvement of crystallinity as well as the enlarged boundary areas. The present study opens a new way to fabricate CuO films, and the high magnetic field is an effective way to tuning the oxygen adsorption.

Mediating distribution of magnetic Co ions by surfactant in Co-doped SnO2 nanorods.

We demonstrate a method to control the distribution of magnetic Co ions in Co-doped SnO2 nanorods by the surfactant. The nanorods with nanoflower morphology have been synthesized by surfactant-assisted hydrothermal method. The X-ray absorption fine structure spectra at Co K-edge reveal that Co ions substitute for Sn site in SnO2 lattice. The X-ray absorption fine structure spectra at O K-edge with its simulated spectra have been performed to investigate the local environment of Co ions. In the experimental spectra, the pre-edge peak continues to decline with the addition of the surfactant. It shows the same trend when the number of clustered Co ions in the simulated spectra is reduced, which indicates that the surfactant suppresses the formation of Co clusters. The effect of surfactant in mediating Co distribution arises from the strong interactions between the Co2+ ions and the CTA+ ions. In the Co K-edge experimental spectra, the weakened pre-edge peak reflects the electron transfer from the CTA+ ions to Co 3d band. Such electron transfer changes the charge state of Co ions and modifies the electrostatic interactions among dopant ions, leading to the uniform distribution of substitutional Co dopants. These results provide experimental guidance in the synthesis of the homogeneous-doped metal oxide semiconductors.

Analysis of genetic distance by SSR in waxy maize.

We examined the genetic diversity of 80 inbred waxy maize lines using 22 SSR molecular markers that could be used to achieve heterosis in waxy maize. Eighty inbred waxy maize lines with different phenotypes, 40 yellow, 25 white, 13 black, and two red lines were analyzed by SSR molecular marker fingerprint and cluster analysis. Using a standard genetic distance of 0.55, the 80 waxy maize inbred lines were clustered into nine groups. Among them, group II, group V, groups VII and VIII, and group IX were divided into three subgroups at a genetic distance of 0.46, into two subgroups at 0.49, into two subgroups at 0.46, and into four subgroups at 0.493, respectively. All but one of the yellow waxy maize inbred lines were clustered in groups VI, VII, VIII, and IX. Group IX (30 lines) contained 28 yellow lines; the other 11 yellow lines were distributed among groups VI, VII and VIII. Among the 25 white lines, 21 were clustered in groups III, V, VI and the third subgroup of group II. The black line N72 was in a group of its own. The black lines N75, N76 and N78 were distributed in groups VII, VIII and IX, respectively. The other nine black lines were clustered in group II. The red lines were distributed in the second subgroup of group II and there was no difference in genetic distance between them. In conclusion, there were considerable genetic differences among waxy maize inbred lines of different colors. The mean genetic distance of inbred lines of the same color was significantly less than that of lines of different colors. Therefore, we concluded that it was more accurate to determine the difference between the populations using the highly stable DNA genetic markers.