Development of an energy spread analyzer for secondary ion mass spectrometry ion source.

The energy spread (ΔE) of an ion source is an important parameter in the production of a finely focused primary ion beam applied in secondary ion mass spectrometry (SIMS). A variable-focusing retarding field energy analyzer (RFEA) has been developed and tested with an Ar+ beam and an oxygen ion beam extracted from a 2.45 GHz microwave ion source, which is developed as a candidate ion source for SIMS applications. The simulation results show that the relative resolution ΔE/E of the designed RFEA reaches 7 × 10-5. The experimental results indicate that a focusing electrode can improve the ΔE measurement results, which is consistent with the simulation results. The ion energy distributions of the Ar+ beam and oxygen ion beam are of Gaussian distribution with the value of ΔE of 3.3 and 2.9 eV, respectively. These results indicate that the designed RFEA is reliable for measuring the ion beam energy spread. The developed RFEA is also used to study the plasma behavior in different settings, which reveals that plasma stability is critical to making a low energy spread ion beam. This paper will present the simulation, design, and test of the variable-focusing RFEA. Preliminary ion beam quality studies with this instrument will also be discussed.

Association between Iodized Salt Intake and Cognitive Function in Older Adults in China.

OBJECTIVES: To investigate the association between iodized salt intake and cognitive function in older adults. DESIGN: A cross-sectional study. SETTINGS: Individuals from the Zhejiang Major Public Health Surveillance Program (ZPHS). PARTICIPANTS: Data of 10,217 participants (including 4,680 coastal residents and 5,537 inland residents) aged ≥ 60 years were analyzed. MEASUREMENTS: Salt intake was evaluated using a questionnaire, and participants were stratified into the following three groups: iodized salt, non-iodized salt, and mixed salt. Cognitive function was assessed through the Mini-Mental State Examination and defined using education-specific cut-off points. Logistic regression models controlling for an extensive range of potential confounders were generated to examine the association between salt intake and cognitive function among all participants. RESULTS: Data from 10,217 participants with a 16.1% prevalence of cognitive impairment were analyzed. Compared with non-iodized salt intake, consumption of iodized salt was inversely associated with cognitive impairment (odds ratio [OR], 0.410; 95% confidence interval [CI], 0.351-0.480; P < 0.001) in all participants after multivariable adjustment. An association between iodized salt intake and cognitive impairment was observed in coastal (OR, 0.441; 95% CI, 0.340-0.572; P < 0.001) and inland residents (OR, 0.569; 95% CI, 0.439-0.738; P < 0.001). Despite the insufficient sample size, the results for individuals consuming mixed salt suggested an inverse association between mixed salt intake and cognitive impairment among coastal residents (OR, 0.598; 95% CI, 0.405-0.885; P = 0.010) after multivariable adjustment. CONCLUSION: Our results indicate that iodized salt intake may reduce the risk of cognitive impairment in older adults living in coastal or inland areas, and the protective effect of iodized salt intake is greater in coastal areas than in inland areas.

A compact radio-frequency ion source for high brightness and low energy spread negative oxygen ion beam production.

A high brightness and low energy spread (∆E) ion source is essential to the production of a high-quality primary ion beam applied in secondary ion mass spectrometry (SIMS). A compact 13.56 MHz radio-frequency (RF) ion source with an external planar spiral antenna has been developed as a candidate ion source for the production of negative oxygen ion beams for SIMS application. This ion source is designed with a three-and-a-half-turn water-cooled planar antenna for RF power coupling, a multi-cusp magnetic field for effective plasma confinement, and a three-electrode extraction system. The experimental results show that more than 50 µA negative oxygen ion beams have been extracted, which consist of 56% O-, 25% O2-, and 19% O3-. The ion energy distribution of the negative oxygen ion beam exhibits a Gaussian distribution with a minimum ∆E of 6.3 eV. The brightness of the O- beam is estimated to be 82.4 A m-2 Sr-1 V-1. The simulation, design, and experimental study results of this RF ion source will be presented in this paper.

Simulation of beam extraction and space charge effect in an electromagnetic isotope separator.

Space charge effect of intense ion beam has critical influence on separation efficiency in the electromagnetic isotope separator. In this paper, a ribbon beam extraction system with slit electrodes for an electromagnetic isotope separator was designed and studied. The extracted beam currents were varied from 10 to 40 mA and the corresponding extracted beam energies were 40 keV and 100 keV respectively. The simulated output beam density distributions were used in the subsequent multi species particle transmission simulation with the space charge effect included. The separated isotope beam spot distributions at the focal plane were simulated under different space charge compensation factors and thus the optimum operation gas pressures in vacuum box were roughly estimated. For the case of high intensity and high power isotope beam collection, an isotope collector with a deceleration electrode was proposed to mitigate the effect of high power beam bombardment and the resultant temperature rising on the collector surface.

[Advances in nutritional support therapy for stroke prevention and treatment].

As a serious disease of death and disability, stroke constitutes a serious threat to human health. Because of stroke patients often have high-risk factors of malnutrition such as dysphagia and autonomic eating disorder, the hospitalization time, mortality and disability rate of stroke patients increases. Nutritional therapy can effectively improve the malnutrition of patients, which are of great significance for the treatment and rehabilitation of stroke and the prevention of its complications. Nutrients are important components of nutrition therapy, and different ways of nutrition therapy directly affect the effect of treatment. This article summarizes effects of nutrients and different nutritional treatments on stroke prevention, morbidity and treatment, and provides a theoretical basis and new thinking for further reducing the incidence rate of stroke, improving the quality of life in patients and reducing the financial burden of society and family.

Prevalence and antimicrobial resistance of Salmonellaisolates from goose farms in Northeast China.

BACKGROUND: Salmonella is one of the most important enteric pathogenic bacteria that threatened poultry health. AIMS: This study aimed to investigate the prevalence and antimicrobial resistance of Salmonella isolates in goose farms. METHODS: A total of 244 cloacal swabs were collected from goose farms to detect Salmonella in Northeast China. Antimicrobial susceptibility, and resistance gene distribution of Salmonella isolates were investigated. RESULTS: Twenty-one Salmonella isolates were identified. Overall prevalence of Salmonella in the present study was 8.6%. Among the Salmonella isolates, the highest resistance frequencies belonged to amoxicillin (AMX) (85.7%), tetracycline (TET) and trimethoprim/sulfamethoxazole (SXT) (81%), followed by chloramphenicol (CHL) (76.2%), florfenicol (FLO) (71.4%), kanamycin (KAN) (47.6%), and gentamycin (GEN) (38.1%). Meanwhile, only 4.8% of the isolates were resistant to ciprofloxacin (CIP) and cefotaxime (CTX). None of the isolates was resistant to cefoperazone (CFP) and colistin B (CLB). Twenty isolates (95%) were simultaneously resistant to at least two antimicrobials. Ten resistance genes were detected among which the bla TEM-1, cmlA, aac(6')-Ib-cr, sul1, sul2, sul3, and mcr-1.1 were the most prevalent, and presented in all 21 isolates followed by tetB (20/21), qnrB (19/21), and floR (15/21). CONCLUSION: Results indicated that Salmonella isolates from goose farms in Northeast China exhibited multi-drug resistance (MDR), harboring multiple antimicrobial resistance genes. Our results will be useful to design prevention and therapeutic strategies against Salmonella infection in goose farms.

Association between Depressive Symptoms and Supplemental intake of Calcium and Vitamin D in Older Adults.

OBJECTIVES: We explored the associations between depressive symptoms and supplemental calcium and vitamin D intake in older adults. DESIGN: This was a prospective cohort study. PARTICIPANTS: 8,527 older adults aged ≥60 years from Zhejiang Major Public Health Surveillance Program (ZPHS) without depressive symptoms at baseline survey. MEASUREMENTS: Participants were divided into non-supplementation, calcium (Ca), vitamin D, and calcium plus vitamin D (CaD) groups based on their supplemental intake during the past year. Depressive symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9). Binary logistic regression analyses were performed to examine the association between depressive symptoms and supplemental intake. RESULTS: When compared to the non-supplementation group, the Ca group exhibited a significant odds ratio (OR) of 0.731 (95% CI: 0.552-0.967, P=0.028). After adjusting for age, sex, and Ca food sources, the OR was even smaller for the CaD group (OR: 0.326; 95% CI: 0.119-0.889, P=0.029). Additionally, our results indicated that taking Ca supplements ≥4 days/week yielded a significant OR of 0.690 (95% CI: 0.492-0.968) after full adjustment. Taking CaD supplements ≥4 days/week yielded a significant OR of 0.282 (95% CI: 0.089-0.898) after adjusting for age, sex, and Ca food sources. CONCLUSIONS: Supplemental intake of Ca or CaD ≥4 days/week can decrease the risk of depressive symptoms in older adults, although CaD supplements may be more effective.

Effects of CYP3A4 polymorphisms on the plasma concentration of voriconazole.

Voriconazole is frequently utilized for the prevention and treatment of invasive fungal infections (IFIs), and is extensively metabolized by the cytochrome P450 (CYP) system. The impact of activity of the genes encoding CYP3A4, CYP3A5, and CYP2C9 on the pharmacokinetics of voriconazole cannot be ignored because, second to CYP2C19, they are the most important enzymes involved in voriconazole metabolism. The influence of genetic polymorphisms in CYP3A4, CYP3A5, and CYP2C9 on the plasma concentrations of voriconazole was evaluated in the present study. The study cohort comprised 158 patients with IFIs in whom 22 single-nucleotide polymorphisms (SNPs) in CYP3A4, CYP3A5, and CYP2C9 were genotyped using the Sequenom MassARRAY RS1000 system, and voriconazole plasma concentrations were measured by high-performance liquid chromatography (HPLC). 40, 91, and 27 patients presented with low (<1 mg/L), normal (1-4 mg/L), and high (>4 mg/L) plasma voriconazole concentrations, respectively. Correlation analysis between polymorphisms and the plasma voriconazole concentration revealed an association between the presence of the rs4646437 T allele and a higher plasma voriconazole concentration [p = 0.033, odds ratio (OR) = 2.832, 95% confidence interval (CI) = 1.086-7.384]. This study has identified a new SNP related to the metabolism of voriconazole, potentially providing novel insight into the influence of CYP3A4 on the pharmacokinetics of this antifungal agent.

[A fluctuographic analysing of EEG patients with paroxysmal headache].

OBJECTIVE: To offer reference of the screening procedure for aircrew and astronaut selection. METHOD: The competitive frequency-fluctuation characteristics of the dominant frequency in the band of 7-12 Hz in EEG and power density spectra of alpha band power-fluctuation were analyzed with a newer system of electroencephalofluctuographic technology in 20 patients (male 13, female 7, aged 17-37 years) with paroxysmal headache. RESULT: During episodes of headache in the affected sites the cumulated dominant fluctuation probability of each frequency components was in the order of 7, 8, 9, 10, 11, 12 Hz from high to low; The relative entropy value was 92.25% +/- 3.41%; Two peaks having at least 25% higher value than those of its neighbors were observed at 1.86 mHz and 4.65 mHz in power density spectra of power-fluctuation. During the intervals of episodes the above-mentioned probability character disappeared; The relative entropy value was decreased to 69.08% +/- 4.16% ; A new peak was found at 0.93 mHz in spectra power-fluctuation, with a reduction in peak value power at 4.65 mHz. CONCLUSION: It not only offered a parameter for pathophysiological and functional evaluation of paroxysmal headache, but also provided reference of the screening procedure for aircrew and astronaut selection.

[Pharmacognostical identification of antelope horn(Cornu Saigae Tataricae) and its adulterants].

OBJECTIVE: To provide appropriate information and scientific basis for identifying antelope horn (Saiga tatarica) contained in traditional Chinese patent medicines, and formulate relevant quality criteria through experiments. METHOD: Conducting comparative identification of macroscopic and microscopic characteristics of antelope horn(Saige tatarica) and its adulterants (Procapra gutturosa, Pantholops hodgsoni, Ovis ammon and Capra hircus) and giving a comparative table and an indented key to the main characteristics. RESULT AND CONCLUSION: There are remarkable differences between the authentic product and adulterants in both macroscopic and microscopic characteristics.

Dominant frequency uncertainty analysis of EEG alpha activity in pilots with transient ischemic attacks.

Objective. To study the characteristics of EEG after transient ischemic attack and to offer reference for screening procedure of aircrew and astronaut selection. Method. The dominant frequency uncertainty of alpha band EEG in 12 pilots (males; age 30 +/- 5) with transient ischemic episodes in middle cerebral artery (MCA) territories and in 20 normal healthy pilots was analyzed with frequency-fluctuation analysis. Result. The dominant probability of the main frequency coinciding with sites affected by transient ischemic attack (TIA) in patient pilots was higher than that in healthy pilots (P<0.01), and the dominant probability ratio logarithmic index I >or= 0 in all patient pilots with normal EEG, but I<0 in all healthy pilots. It was also found that not only I >or= 0, but the second component shifted to lower frequency (8 Hz) in patients with slight focal EEG alterations, i.e. slowing of frequency. The relative entropy values (percentage) were decreased significantly in pilots with TIA as compared with healthy pilots (P<0.05). Conclusion. The dominant frequency uncertainty analysis of alpha band showed clear superiority of computerized evaluation over routine visual assessment for the diagnosis of minor cerebral ischemia. It offers not only a possibility of studying pathophysiological functional parameter, but also the reference for screening procedure in aircrew and astronaut selection.

[Determination of esculetin in semen Euphorbiae lathyridis L. by TLCS and comparison on the quality in different areas].

A TLC-densitometric method for the determination of oesculetin in Semen Euphorbia lathyridis (Euphorbiae lathyrdis) was established, and esculetin content in Semen Euphorbia lathyridis from three different producing areas (Zhengzhou, Chengdu and Chongqing) was determined. The method is accurate, sensitive and simple. The recovery is 98.63% and the coefficient of variation is 1.59% (n = 5). The esculetin average contents in the three samples are 0.3013%, 0.2046% and 0.2094% respectively.