Diabetes self-risk assessment questionnaires coupled with a multimedia health promotion campaign are cheap and effective tools to increase public awareness of diabetes in a large Chinese population

AIMS

To evaluate costs and effectiveness of implementing a diabetes self-risk assessment (Diabetes Risk Score) questionnaire coupled with a multimedia health promotion campaign on changes in diabetes awareness in a large diabetes prevention programme.

METHODS

Between 2007 and 2010, a multimedia health promotion campaign was conducted targeting the 1.94 million population of Qingdao, China, using newspapers, radio programmes, distribution of free booklets and Diabetes Risk Score flyers. Diabetes awareness questionnaires filled out by people first interviewed in 2006 (survey A), before the initiation of the campaign, were compared with those first interviewed between 2007 and 2010 during the campaign period (survey B). The rates of diabetes awareness in both surveys were studied amongst adults aged 35-74 years without a prior history of diabetes, but with a Diabetes Risk Score of ≥ 14.

RESULTS

In survey B, 85, 82 and 76% of the urban participants correctly recognized obesity, family history of diabetes and physical inactivity, respectively, as important risk factors for diabetes; while the awareness rates were 43, 46 and 25%, respectively, in survey A (P < 0.001). The corresponding figures among rural participants were 65, 63 and 53% in survey B and 29, 22 and 11% in survey A (P < 0.001). To cover 1000 individuals, the programme spent €5.4 on the use of the Diabetes Risk Score flyer, €31.3 on the education booklet, €7.7 on the newspaper campaign and €37.5 on radio programmes.

CONCLUSIONS

The combination of a Diabetes Risk Score questionnaire with a multimedia health promotion campaign is a cheap and effective health promotion tool to raise public awareness of diabetes.

Ultrafast insulator–metal phase transition in vanadium dioxide studied using optical pump–terahertz probe spectroscopy

We studied the ultrafast dynamic behavior of the photoinduced insulator–metal phase transition in VO2 thin film using optical pump–terahertz probe spectroscopy with different excitation fluences and at different temperatures. We observed two processes in the insulator–metal phase transition in VO2: a fast process and a slow process. The fast process is a nonthermal process, which is ascribed to the nucleation of the metal phase, while the slow process is strongly affected by temperature and is ascribed to the thermally driven growth and coalescence of metal domains in VO2. The transient complex conductivity spectra at different delay times are also investigated.

Enhancement of bandgap emission of Pt-capped MgZnO films: important role of light extraction versus exciton-plasmon coupling

We present on a systematic study of the contribution of surface plasmon (SP) coupling and light extraction toward emission enhancement of Platinum (Pt) nano-patterns capped MgZnO films. Time resolved Photoluminescence (PL) results indicate that the Pt coating can greatly reduces the non-radiative recombination rate by passivation of surface states, making the decay slow down. Temperature dependence of the integrated photoluminescence intensity reveals that the Pt nano-patterns can offer a large amount of light transfer and scattering, which enormously increase the light extraction efficiency up to 3.8-fold. These results indicate that the increased light extraction efficiency caused by surface modification via Pt coating rather than SP coupling plays a dominant role in increasing bandgap emission of MgZnO film.

In-line silica capillary tube all-silica fiber-optic Fabry-Perot interferometric sensor for detecting high intensity focused ultrasound fields

Aiming at detecting high intensity focused ultrasound (HIFU) fields, this letter reports on a novel in-line silica capillary tube all-silica fiber-optic Fabry-Perot (ILSCT-ASFP) interferometric sensor fabricated by splicing a commercially available silica capillary tube to two single-mode fibers. The experimental results show that such a novel ILSCT-ASFP interferometric sensor with a cavity length of ∼60.76 μm has an excellent fringe visibility of up to ∼20 dB, and the fringe visibility is still good when the cavity length extends up to ∼1031.07 μm. The measured wavelength-temperature sensitivity of 0.000858 nm/°C shows that the wavelength drift of the fabricated ILSCT-ASFP interferometric sensor towards temperature is extremely low. Meanwhile, the measurement of HIFU fields by this novel sensor is demonstrated, and the experimental results indicate that the signal-to-noise ratio of the sensing system for sensing a 0.93 MHz HIFU field with a pressure of 2.69 MPa in the focus area can reach 42.8 dB. The corresponding noise equivalent pressure is 0.0194 MPa, and the calculated acoustic sensitivity is 65.4 mV/MPa over a 2.5 MHz measurement bandwidth.

Association of multi-pathogenic infections with BAT2, CXCL12, Mx1 and EHMT2 variations in pigs

Porcine reproductive and respiratory syndrome virus (PRRSV), Haemophilus parasuis and Pseudorabies become a widespread problem causing great economic losses associated with reproductive disturbance, respiratory diseases, neonatal mortality, fibrinous polyserositis, meningitis and arthritis in the pig industry. The important candidate genes are assumed to play crucial roles in host defense against the diseases. The aims of this study were to evaluate the variants in HLA-B associated transcript 2 (BAT2), CXCL12, myxovirus resistance protein 1 (Mx1) and EHMT2 genes and their effects on the risk of infection PRRSV and H. parasuis in a case-control (diseased-healthy pigs) population of Duroc × Landrace × LargeWhite. The results showed that the mutations in BAT2, Mx1 and EHMT2 genes were significantly associated with the antibody and the reisk of infection PRRSV and H. parasuis. Those individuals with AA genotype of BAT2 had significantly higher Pseudorabies virus antibody than that with GG and GA (P < 0.05), and the individuals with TT genotype of EHMT2 generated higher Hog Cholera and Pseudorabies virus antibody than that wtih GG and GA (P < 0.01). These results indicated that the polymorphisms in Mx1, BAT2 and EHMT2 genes changed the diseases susceptibility and could be the potential markers assisting the pig breeding selection and disease resistance.

Effects of FUT1 gene mutation on resistance to infectious disease

Alpha-(1,2)-fucosyltransferase (FUT1) gene has been identified as a candidate gene for regulating the expression of Escherichia coli F18 receptor gene (ECF18R) which promotes adherence of Enterotoxigenic (ETEC) and Verotoxigenic (VTEC) Escherichia coli (E. coli) via F18 fimbriae. In order to illustrate the polymorphisms of FUT1 and their effects on resistance to natural infection by Porcine Respiratory and Reproductive Symdrome Virus (PRRSV) and Haemophilus parasuis, the distributions of different genotypes and the relative risks of disease incidence in pigs were investigated. A total of 1,041 pigs representing three European breeds (Duroc, Landrace and LargeWhite), five Chinese local breeds (Wild pig, Small MeiShan, QinPing, JinHua, and JianLi) and three commercial populations (LargeWhite × JianLi, Duroc × Landrace × LargeWhite and Duroc × wild pig) were selected to analyze the genotype of the FUT1 gene by PCR-RFLP. Only the GG genotype associated with susceptibility to ECF18 bacteria was detected in Chinese local pig breeds and a population of LargeWhite × JianLi, while the AA genotype which confers resistance to ECF18 was detected in two European breeds (Duroc and LargeWhite), two populations of Duroc × wild pig and Duroc × Landrace × LargeWhite. Regarding relative risk of incidence, Duroc × Landrace × LargeWhite with genotypes GG or AG showed greater relative risk (OR = 2.040, P = 0.025; OR = 1.750, P = 0.081, respectively) than those with genotype AA during natural infection by both PRRSV and Haemophilus parasuis. It can be concluded that the mutation of FUT1 gene might play a role in pig infection by multi-pathogens, and that AA may be a favourable genotype for increasing the resistance to disease.

Prevalence of metabolic syndrome in rural and urban Chinese population in Qingdao

AIMS

To investigate the prevalence of metabolic syndrome and its components in both rural and urban Chinese population.

SUBJECTS AND METHODS

A population-based crosssectional survey was conducted in Qingdao, China in 2006 with 6100 Chinese aged 35-74 yr invited and 5355 who attended; 3357 subjects, 1562 urban (46.5%) and 1795 rural residents (53.5%) met the inclusion criteria for the current data analysis. The metabolic syndrome definitions of National Cholesterol Education Program Adult Treatment Expert Panel III (NCEPATPIII) 2004, NCEP 2005 and International Diabetes Federation (IDF) were used.

RESULTS

The age-standardized prevalences of metabolic syndrome were 16.2%, 32.2%, and 28.3% in men and 26.8%, 37.2%, and 34.6%in women, according to the definitions of the NCEP 2004, NCEP 2005, and IDF, respectively. Urban men have more risk factors and higher prevalence of the metabolic syndrome than rural men, but the differences in women were not that striking. Elevated blood pressure (62.6%) was, among risk factors, most common in the study population, followed by central obesity (53.4%), and hyperglycemia (52.2%) defined using the NCEP 2005 criteria.

CONCLUSIONS

Metabolic disorders were common among adult Chinese in both rural and urban areas in Qingdao.

The association of gamma-glutamyltransferase and C-reactive protein with IFG/IGT in Chinese adults in Qingdao, China

BACKGROUND

Serum gamma-glutamyltransferase (GGT) and C-reactive protein(CRP) have been previously shown to be associated with impaired fasting glucose/impaired glucose tolerance (IFG/IGT), but such an association has not been well verified, and is examined in a non-diabetic Chinese population.

METHODS

A population-based cross-sectional study was conducted in 2006 in Qingdao, China. Data of 1143 men and 1689 women aged 35-74 years and free of diabetes at baseline were analyzed. Multivariable logistic regression analysis was performed to estimate the odds ratio (OR) and its 95% confidence interval (CI).

RESULTS

Compared with the lowest quartile, the ORs (95%CI) for IFG/IGT corresponding to the highest quartile were 0.89(0.61,1.28) in men and 0.87(0.64,1.18) in women for CRP and 2.12(1.40,3.38) and 1.87(1.32,2.62) for GGT, when the two were fitted simultaneously in a model adjusting for age, school years, alcohol-drinking, smoking, family history of diabetes, systolic blood pressure, waist circumference, triglycerides and high-density lipoprotein.

CONCLUSIONS

The elevated GGT, but not CRP, was independently associated with the presence of the IFG/IGT in both genders in this Chinese population.

Low dose of gamma irradiation enhanced boronophenylalanine uptake in head and neck carcinoma cells for boron neutron capture therapy

This study attempted to increase the boron uptake of human head and neck carcinoma SAS cells for BNCT by using a gamma dose of 0.1 Gy for combined treatment. Intracellular boron concentrations in 25 μgB/mL medium of BPA treated and BPA combined gamma-irradiation treated SAS cells were 73.8±1.73 and 95.15±1.36 ppm, respectively. After neutron irradiation, the G2/M-phase cell populations of untreated, BPA treated and BPA combined gamma-irradiation treated SAS cells were 19.31±1.71%, 52.47±2.25% and 59.19±2.63%, respectively. Experimental results indicate that the low dose gamma radiation with combination BPA treatment has the highest killing rate after neutron irradiation. Capable of significantly increasing the G2/M arrest after neutron irradiation, the combined treatment of a low dose of gamma irradiation with 25 μg B/mL medium of BPA also provided a higher killing effect for BNCT.

Note: Diagnosing femtosecond laser-solid interactions with monochromatic Kα imager and x-ray pinhole camera

An x-ray pinhole camera and a monochromatic K(α) imager are used to measure the interactions of intense femtosecond laser pulses with Cu foil targets. The two diagnostics give different features in the spot size and the laser energy scaling, which are resulted from different physical processes. Under our experimental conditions, the K(α) emission is mainly excited by the fast electrons transporting inside the cold bulk target. In contrast, the x-ray pinhole signals are dominated by the broadband thermal x-ray emission from the hot plasma at the front target surface.

Effect of prepulse on fast electron lateral transport at the target surface irradiated by intense femtosecond laser pulses

The effects of preplasma on lateral fast electron transport at front target surface, irradiated by ultraintense (>10(18) W/cm2) laser pulses, are investigated by Kα imaging technique. A large annular Kα halo with a diameter of ∼560 μm surrounding a central spot is observed. A specially designed steplike target is used to identify the possible mechanisms. It is believed that the halos are mainly generated by the lateral diffusion of fast electrons due to the electrostatic and magnetic fields in the preplasma. This is illustrated by simulated electron trajectories using a numerical model.

Prevalence, severity, and time trends of allergic conditions in 6-to-7-year-old schoolchildren in Taipei

BACKGROUND

Atopic diseases, including asthma, allergic rhinitis, and atopic eczema, are major illnesses among children. Recent studies conducted worldwide have shown diverse trends in the prevalence of asthma, with a steady increase detected in industrialized countries. Other studies, however, have revealed a leveling trend or even a declining prevalence.

OBJECTIVE

The purpose of this study was to evaluate the current prevalence of allergic conditions in 6-to7-year-old schoolchildren in Taipei, Taiwan, and to analyze time trends.

METHODS

We evaluated the prevalence and severity of asthma and other allergic conditions using a phase I International Study of Asthma and Allergies in Childhood core written questionnaire previously administered in Taipei in 1994 and 2002.

RESULTS

A total of 24 999 first-grade students from 153 elementary schools completed the questionnaire. The proportion of children with wheeze ever and nocturnal cough in the past 12 months was significantly increased in 2007 compared to 1994 and 2002. No significant differences were detected in the prevalence of current wheeze or physician-diagnosed asthma. The prevalence of severe wheezing symptoms in the past 12 months (> or = 4 attacks of wheeze, > or = 1 night of sleep disturbance due to wheeze per week, wheeze-limiting speech, and exercise-induced wheeze) decreased significantly. The prevalence and severity of rhinitis symptoms increased significantly during the 13-year period analyzed. The prevalence of eczema symptoms-defined as recurrent itchy rash and typical atopic eczema distribution in the past 12 months--also increased.

CONCLUSIONS

We observed an increase only in the prevalence and severity of current allergic symptoms in allergic rhinitis and atopic eczema.

Topiramate in prevention of cluster headache in the Taiwanese

Topiramate could potentially effective as prophylaxis for cluster headache, but the experience remains limited in Asians. We performed an open-label clinical study to evaluate the efficacy of topiramate in the tolerable dosage to prevent cluster headache. We studied patients who fulfilled the criteria of episodic or chronic cluster headaches (International Classification of Headache Disorders second edition) prospectively. Headache severity was assessed using a verbal rating scale (excruciating, severe, moderate, mild, and no headache). Treatment was started with a topiramate dose of 50 mg twice daily and was increased by 50-100 mg a day every 3 to 7 days as tolerated to a maximal daily dosage of 400 mg. Of the 12 patients with episodic cluster headache, nine patients had remission of headache at a mean daily dosage of 273 mg (range 100-400 mg), and the patient with chronic cluster headache had remission at a daily dosage of 400 mg. The adverse effects included: paresthesia (84%), slow speech (54%), and dizziness (46%), but were tolerated by most patients. Two patients discontinued topiramate due to adverse events and one due to lack of efficacy. This open-label study suggests that topiramate is effective in the treatment of cluster headache in Taiwanese patients.

Nontraumatic hemorrhagic stroke in young adults in taiwan

We reviewed the medical records and imaging studies on the in-hospital patients to investigate the clinical and etiological patterns in hemorrhagic stroke in young patients. We evaluated 210 patients (131 males and 79 females) aged 15-45 years who had traumatic hemorrhagic stroke between April 1, 1986, and November 30, 1992. Nontraumatic intracerebral hemorrhage was diagnosed in 170 patients (80.9%). The main causes of nontraumatic intracerebral hemorrhage were hypertension, ruptured arteriovenous malformation, and blood dyscrasia. A cause was not found in 42 patients (24.7%). Subarachnoid hemorrhage was found in 40 patients (19.1%). The main causes were ruptured aneurysms and arteriovenous malformations. The overall in-hospital survival of young patients with hemorrhagic stroke was 64.7%. Young adults with nontraumatic intracerebral and subarachnoid hemorrhage are a heterogeneous group. Hypertension accounts for about one-third of intracerebral hemorrhage and is an important preventable cause of hemorrhagic stroke in young adults in Taiwan.

Function analysis of a new type I PKS-SAT domain by SAT-EAT domain replacement

The function of a new starter unit acyltransferase (SAT) domain SAT-EF080951 (GenBank accession number) encoded in a new type I polyketide synthase (PKS) gene cluster EF568935 (GenBank accession number) isolated for this study was analyzed by domain replacement with an extender unit AT (EAT) domain of avermectin PKS. It was shown that the SAT-EF080951 incorporated malonyl-CoA specifically in vivo, which contradicted the specificity that we had previously determined by substrate binding test in vitro. The result of this study indicates that type I PKS-SAT can alter its specificity in vivo and functions well in extender units and proved the feasibility of the SAT-EAT domain replacement in type I PKS. We propose that SAT-EAT replacement strategy could be a novel route for increasing the diversity of new polyketides combinatorially biosynthesized. The new type I PKS-SAT-EF080951 studied herein may be further employed for related studies on enzymology or combinatorial biosynthesis of polyketides.

A simple Chinese risk score for undiagnosed diabetes

AIMS

A diabetes risk score for screening undiagnosed diabetes was constructed and validated in Chinese adults.

METHODS

Two consecutive population-based diabetes surveys among Chinese adults aged 20-74 years were conducted in 2002 (n = 1986) and 2006 (n = 4336). Demographic and anthropometric measures were collected following similar procedures. Standard 2-h 75-g oral glucose tolerance tests (OGTTs) were performed to diagnose diabetes in both surveys. Fasting capillary plasma glucose (FCG) and glycated haemoglobin (HbA(1c)) were also measured together with the OGTTs on the same day of the 2006 survey. Beta coefficients estimated using logistic regression analysis derived from data of the 2002 survey were used to develop the risk assessment algorithm. The performance of the algorithm was validated in the study population of the 2006 survey.

RESULTS

Of all the variables tested, waist circumference, age and family history of diabetes were significant predictors of diabetes and were used to construct the risk assessment score. The score, ranging from 3 to 32, performed well when applied to the study population of the 2006 survey. The area under the receiver operating characteristic curve was 67.3% (95% CI, 64.9-69.7%) for the score, while it was 76.3% (73.5-79.0%) for FCG alone and 67.8% (64.9-70.8%) for HbA(1c) alone. At a cut-off point of 14, the sensitivity and specificity of the risk score were 84.2% (81.0-87.5%) and 39.8% (38.2-41.3%).

CONCLUSIONS

The risk score based on age, waist circumference and family history of diabetes is efficient as a layperson-oriented diabetes screening tool for health promotion and for population-based screening programmes.

Inactivation of fibroblast growth factor receptor signaling in myelinating glial cells results in significant loss of adult spiral ganglion neurons accompanied by age-related hearing impairment

Hearing loss has been attributed to many factors, including degeneration of sensory neurons in the auditory pathway and demyelination along the cochlear nerve. Fibroblast growth factors (FGFs), which signal through four receptors (Fgfrs), are produced by auditory neurons and play a key role in embryonic development of the cochlea and in neuroprotection against sound-induced injury. However, the role of FGF signaling in the maintenance of normal auditory function in adult and aging mice remains to be elucidated. Furthermore, the contribution of glial cells, which myelinate the cochlear nerves, is poorly understood. To address these questions, we generated transgenic mice in which Fgfr1 and Fgfr2 were specifically inactivated in Schwann cells and oligodendrocytes but not in neurons. Adult mutant mice exhibited late onset of hearing impairment, which progressed markedly with age. The hearing impairment was accompanied by significant loss of myelinated spiral ganglion neurons. The pathology extended into the cochlear nucleus, without apparent loss of myelin or of the deletion-bearing glial cells themselves. This suggests that perturbation of FGF receptor-mediated glial function leads to the attenuation of glial support of neurons, leading to their loss and impairment of auditory functions. Thus, FGF/FGF receptor signaling provides a potentially novel mechanism of maintaining reciprocal interactions between neurons and glia in adult and aging animals. Dysfunction of glial cells and FGF receptor signaling may therefore be implicated in neurodegenerative hearing loss associated with normal aging.

Increasing trend in the prevalence of Type 2 diabetes and pre-diabetes in the Chinese rural and urban population in Qingdao, China

AIMS

To determine the secular trend of prevalence of Type 2 diabetes and pre-diabetes in a Chinese population from 2001 to 2006.

METHODS

Two consecutive population-based surveys for diabetes were conducted in a randomly selected population aged 35-74 years and living in Qingdao, China in 2001-2002 (n = 10854) and 2006 (n = 4416). All participants underwent standardized 2-h 75-g oral glucose tolerance tests (OGTTs), along with fasting capillary plasma glucose (FCG) tests in 2006. One urban community underwent OGTTs directly in 2002 (n = 1815), while a two-step screening strategy using FCG as a first-line screening test followed by OGTTs was used in 9039 individuals in 2001. Diabetes and pre-diabetes was defined according to the 2006 World Health Organization/International Diabetes Federation criteria.

RESULTS

Based on the results of direct OGTTs, the age-standardized prevalence of diabetes and pre-diabetes in urban areas was 12.2 and 15.4% in 2002, whereas the prevalences were 18.8 and 28.7% in urban areas and 14.1 and 20.2% in rural areas in 2006 (P < 0.001, in urban areas). Using the two-step screening strategy, the prevalence of diabetes in 2001 was 10.1% in urban and 7.7% in rural areas and 13.8% in urban and 12.2% in rural areas in 2006 (P < 0.001). Based on the data of the 2006 survey, the two-step screening strategy missed 30.2% of diabetes cases when compared with the number defined by the direct OGTT approach.

CONCLUSIONS

Qingdao has experienced a marked increase in the prevalence of diabetes and pre-diabetes in the past 5 years. Intervention to prevent a further increase in the prevalence of diabetes is urgently required.

Heterostructures of germanium nanowires and germanium-silicon oxide nanotubes and growth mechanisms

We report on a method to fabricate one-dimensional heterostructures of germanium nanowires (GeNWs) and germanium-silicon oxide nanotubes (GeSiO(x)NTs). The synthesis of the wire-tube heterostructures is carried out using a simple furnace set-up with germanium tetraiodide and germanium powders as growth precursors, gold-dotted silicon wafers as substrates and by controlling the temperature ramp rate/sequence of the growth precursors. Two types of wire-tube heterostructures resulting from distinct growth mechanisms are obtained. The type-1 heterostructure consists of a GeNW, grown via a gold-catalyzed vapour-liquid-solid process, at the lower end and a GeSiO(x)NT at the upper end. In contrast, the type-2 heterostructure is made up of a solid wire at the upper end and a hollow tube at the lower end. The solid wire portion of the type-2 heterostructure is formed through an oxide-assisted growth process.

Risk factors associated with the dramatic increase in the prevalence of diabetes in the adult Chinese population in Qingdao, China

OBJECTIVE

To investigate the major risk factors and their association with the dramatic increase in the prevalence of diabetes from 2001-2002 to 2006 in Qingdao, China.

METHODS

Population-based cross-sectional studies on diabetes were performed in 4598 men and 7026 women aged 35-74 years. The 2006 World Health Organization diagnostic criteria for diabetes were used.

RESULTS

The crude prevalence of diabetes was 11.3% in both men and women in urban areas and 5.3% and 8.9% in rural areas in 2001-2002. This increased to 19.2% and 16.1% in urban areas and 14.2% and 13.8% in rural areas in 2006 for men and women, respectively. The increase in diabetes prevalence from 2001-2002 to 2006 was paralleled by an increased body mass index in rural areas but not in urban areas. The major risk factors associated with diabetes were age, family history of diabetes, obesity, hypertension and high triglycerides. The multivariate adjusted odds ratio and 95% confidence interval for diabetes corresponding to a one standard deviation increase in waist circumference was 1.81 (1.47, 2.23) in urban men, 1.64 (1.26, 2.13) in rural men, 1.98 (1.66, 2.37) in urban women and 2.02 (1.63, 2.51) in rural women. Low socio-economic classes had a higher risk for diabetes in urban areas but a lower risk in rural areas, both associated with increased waist circumference.

CONCLUSION

Established risk factors are of great importance for the prevalence of diabetes in the urban and rural Chinese populations and changes in these factors could explain the recent dramatic increase in diabetes prevalence, particularly in rural areas. Considering the high prevalence of obesity and physical inactivity, intervention is urgently required in China.

The role of magnetoelastic strain on orbital control and transport properties in an LaTiO(3)-CoFe(2)O(4) heterostructure

Epitaxial heterostructures of CoFe(2)O(4)/LaTiO(3)/LaAlO(3) have been successfully prepared by using the pulsed laser deposition technique. The magnetoresistance (MR) of the samples is negative and linear with field at H≥2 T, exhibiting no dependence on field directions. Nevertheless, when H<2 T, the MR is negative in a field parallel to the sample plane, but positive in that along the film normal. This novel observed anisotropic MR is explained in terms of the magnetic anisotropy in the ferrimagnetic layer, as well as the magnetoelastic coupling between the two. In fields of different directions, the top CoFe(2)O(4) layer contracts or expands in the sample plane due to the significant magnetostriction effect, changing its resistance accordingly and exerting compressive or tensile strains on the bottom LaTiO(3) layer. Apparently the orbital status and the one-electron bandwidth in the LaTiO(3) layer are altered, which leads to a change in resistance.

Morphology-controlled synthesis and a comparative study of the physical properties of SnO2 nanostructures: from ultrathin nanowires to ultrawide nanobelts

Controlled synthesis of one-dimensional materials, such as nanowires and nanobelts, is of vital importance for achieving the desired properties and fabricating functional devices. We report a systematic investigation of the vapor transport growth of one-dimensional SnO(2) nanostructures, aiming to achieve precise morphology control. SnO(2) nanowires are obtained when SnO(2) mixed with graphite is used as the source material; adding TiO(2) into the source reliably leads to the formation of nanobelts. Ti-induced modification of crystal surface energy is proposed to be the origin of the morphology change. In addition, control of the lateral dimensions of both SnO(2) nanowires (from approximately 15 to approximately 115 nm in diameter) and nanobelts (from approximately 30 nm to approximately 2 microm in width) is achieved by adjusting the growth conditions. The physical properties of SnO(2) nanowires and nanobelts are further characterized and compared using room temperature photoluminescence, resonant Raman scattering, and field emission measurements.

The robotic radiosynthesis of 5-[(18)F]fluoro-2'-deoxyuridine and its biological characterization

5-[(18)F]fluoro-2'-deoxyuridine ([(18)F]FUdR) was synthesized using a robotic system as a proliferation probe for PET. [(18)F]FUdR was prepared via radiofluorodestannylation reaction from its organotin precursor. Biodistribution study and microPET imaging of [(18)F]FUdR in NG4TL4 sarcoma-bearing FVB/n mice were performed. The tumor-to-blood and tumor-to-muscle ratio increased steadily from 15 (1.81 and 3.42) to 120min (9.10 and 11.9) post injection. The dynamic microPET imaging demonstrates remarkable radioactivity retention in the tumor, which is consistent with the results of biodistribution study.

Digital I/Q demodulation for KSTAR ion cyclotron range of frequency system

An ion cyclotron range of frequency system requires rf diagnostics for a rf-plasma coupling or for maintaining a correct operation. A detector based on a digital I/Q demodulation technique collects the rf amplitude and phase at the same time without errors from the I/Q imbalance inherent in an analog counterpart. The theory of such a detector was studied and implemented for the first campaign of the KSTAR tokamak. Experimental results of the rf and other diagnostics are presented and discussed.

Optimizing double emulsion process to decrease the burst release of protein from biodegradable polymer microspheres

The process parameters such as the compositions of inner and outer aqueous phase and emulsification technique of the primary emulsion were optimized to decrease the burst release of BSA from biodegradable polymer microspheres in double emulsion method. It was found that diminished burst release of -14% was achieved for the microspheres produced by formulations, where no phosphate was present in the inner water phase (non-buffered system). Primary emulsion made by probe sonication rather than homogenization or mechanical stirring led to microspheres with insignificant burst effect. Microspheres obtained using 0.1% aqueous Tween 80 solution as the outer aqueous phase, frequently exhibit reduced burst effect of 2.7%. Low microsphere yield (52.1%), however, was observed. Microsphere yield was, therefore, enhanced by addition of additive such as sodium chloride, glucose or mannitol into the outer aqueous phase. Decrease in BSA entrapment was observed in the presence of sodium chloride, but reduction in entrapment efficiency was observed in the case of glucose. Burst release increased from 2.7% to 9.5% or 3.4% as 2.5% sodium chloride or 7.5% glucose was added into the outer aqueous phase respectively. Marked burst release (>20%) was observed in the presence of additive of higher concentration independent of sodium chloride or glucose. As far as surfactant type was concerned, diminished burst was found when PVP or Tween 80 rather than PVA was utilized as the surfactant during microsphere preparation. In addition to PLGA, the copolymers of L-lactide (LLA) and dimethyl trimethylene carbonate (DTC) or trimethylene carbonate (TMC) were also evaluated. Insignificant burst effect was found for the microspheres composed of DTC or TMC copolymers.