Total reflection X-ray fluorescence (TXRF) analysis is conducted to determine trace elements in a sample solution, which is dropped onto a substrate and dried. Therefore, the form of the residue ...affects the quantitative results. The absorption of X-ray fluorescence (XRF) follows the Lambert-Beer law; the absorption effect of XRF in a thick residue (dotted-type residue) is stronger than that in a thin residue (film-type residue). The absorption effect is particularly remarkable during the determination of low-
Z
elements in a high-elemental concentration solution. In this study, we propose a new film-like-residue preparation process based on the freeze-drying method to obtain accurate TXRF results. The sample solution is dropped onto the substrate and inserted into a chamber. The chamber is cooled using liquid nitrogen; resultantly, an aliquot of the sample is frozen. The chamber is depressurized using a vacuum pump, and the freeze-dried residue is prepared by maintaining the chamber at room temperature. To evaluate the efficiency of the freeze-drying-based method for sample preparation for TXRF analysis, we prepare a multi-element solution containing high-elemental concentration components. For the residue prepared using the freeze-drying method, the relative standard deviations of the quantitative values and the minimum detection limits are improved because the absorption effect is weakened. The sample preparation process based on the freeze-drying method facilitates accurate TXRF analysis of high-elemental concentration solutions and can be applied for the analysis of trace elements in different types of solutions such as environmental water and wastewater.
To prepare the spread residue, the freeze-drying method is introduced to total reflection X-ray fluorescence (TXRF) analysis.
A water-soluble cyclophane dimer having two disulfide groups as a reduction-responsive cleavable bond as well as several acidic and basic functional groups as a pH-responsive ionizable group 1 was ...successfully synthesized. It was found that 1 showed pH-dependent guest-binding behavior. That is, 1 strongly bound an anionic guest, 6-p-toluidinonaphthalene-2-sulfonate (TNS) with binding constant (K/M−1) for 1:1 host-guest complexes of 9.6 × 104 M−1 at pH 3.8, which was larger than those at pH 7.4 and 10.7 (6.0 × 104 and 2.4 × 104 M−1, respectively), indicating a favorable electrostatic interaction between anionic guest and net cationic 1. What is more, release of the entrapped guest molecules by 1 was easily controlled by pH stimulus. Large favorable enthalpies (ΔH) for formation of host-guest complexes were obtained under the pH conditions employed, suggesting that electrostatic interaction between anionic TNS and 1 was the most important driving force for host-guest complexation. Such contributions of ΔH for formation of host-guest complexes decreased along with increased pH values from acidic to basic solutions. Upon addition of dithiothreitol (DTT) as a reducing reagent to an aqueous PBS buffer (pH 7.4) containing 1 and TNS, the fluorescence intensity originating from the bound guest molecules decreased gradually. A treatment of 1 with DTT gave 2, having less guest-binding affinity by the cleavage of disulfide bonds of 1. Consequently, almost all entrapped guest molecules by 1 were released from the host. Moreover, such reduction-responsive cleavage of 1 and release of bound guest molecules was performed more rapidly in aqueous buffer at pH 10.7.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
There have been no reports on prognostic prediction and risk stratification based on stress phase bandwidth (SPBW), or a left ventricular (LV) mechanical dyssynchrony index, in patients with known or ...suspected stable coronary artery disease (CAD) at low or intermediate risk of major cardiac events (MCEs) using the J-ACCESS risk model. We retrospectively investigated 4,996 consecutive patients with known or suspected CAD who underwent rest
201
Tl and stress
99m
Tc-tetrofosmin electrocardiogram (ECG)-gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) and followed up for 3 years to confirm their prognosis. MCE risk over 3 years was estimated using an equation based on that used in the J-ACCESS study. The composite endpoint was the onset of MCEs consisting of cardiac death, non-fatal myocardial infarction (MI), and severe heart failure requiring hospitalization. SPBW was calculated by phase analysis with the Heart Risk View-F software and its normal upper limit was set to 38°. Based on the estimated 3-year incidence of MCEs obtained from the J-ACCESS risk model, 4,123 of the 4,996 consecutive patients were classified as low (
n
= 2,653) or intermediate risk (
n
= 1,470) and they were analyzed for follow-up. During the follow-up, 153 patients experienced MCEs: cardiac death (
n
= 38), non-fatal MI (
n
= 45), and severe heart failure (
n
= 70). The results of the multivariate analysis showed age, estimated glomerular filtration rate (eGFR), stress LV ejection fraction, and stress SPBW to be independent predictors of MCEs. The actual 3-year MCE rate in patients at intermediate risk was significantly higher than in those at low risk (6.7% vs. 2.1%,
P
< 0.0001). However, the actual 3-year MCE rate in patients with abnormal SPBW (> 38°) was 4.0% and 9.2% in low- and intermediate-risk patients, respectively, which corresponded to intermediate and high risk. Kaplan–Meier analysis also showed significant risk stratification by normal SPBW values for both low- and intermediate-risk patients. LV mechanical dyssynchrony assessed with ECG-gated SPECT MPI is useful for risk stratification of known or suspected stable CAD patients at low or intermediate risk of MCEs and may help identify higher risk patients who could not be identified as being at risk based on J-ACCESS risk assessment.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
B–F σ-bond activation of a fluoroborate has been experimentally achieved through reactions with electron-rich iridium(I) and palladium(0) complexes. The selectivity of B–F σ-bond cleavage by iridium ...complexes was improved through the high nucleophilicity of the iridium center, implying that a different pathway from that of well-accepted F– abstraction was in effect. The palladium(0) complex was found to promote exclusive B–F σ-bond cleavage even at ambient temperature. Density functional theory (DFT) calculations suggested that B–F σ-bond activation occurred through an SN2-type pathway, which is, to our knowledge, the first proposal of SN2-type borate–fluorine σ-bond cleavage mediated by a transition metal complex. The high feasibility of the SN2-type pathway appears to be attributed to the relatively low deformation energy of the transition state. It was also found that countercation Cs+ effectively stabilized the transition state and product by serving as a F– acceptor.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
Photocatalytic methane (CH4) production wherein CO2 is reduced to CH4 by utilizing solar radiation energy is gaining research and industrial focus because of its environmental-friendly notion. It ...offers twofold advantages: reduction in CO2 emission and production of artificial natural gas (methane) at the same time. In this paper, comparative energy, economic and environmental assessment of such photocatalytic methane production has been carried out between Japan and Malaysian conditions. Assumptions on the photocatalytic methane production plant and estimation of energy production, CO2 emission reduction, and economic indicators are made based on previous research and existing technologies. Energy analysis shows that Malaysia has a higher potential for energy production and CO2 emission reduction than Japan. Economic analysis reveals that the feasible reaction efficiencies of the plant in Japan and Malaysia are 8%. The slightly higher conversion efficiency in Malaysia is due to the energy price and CO2 tax. For the implementation of the photocatalytic methane production plant, the high energy price and CO2 tax will work as a driving force.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
There are no reports indicating a prognostic difference based on normalization of left ventricular (LV) mechanical dyssynchrony after revascularization in patients with coronary artery disease (CAD). ...We retrospectively investigated 596 patients who underwent rest
201
Tl and stress
99m
Tc-tetrofosmin electrocardiogram-gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging. All patients had significant stenosis with ≥ 75% narrowing of the coronary arterial diameter detected by coronary angiography performed after confirmation of ≥ 5% ischemia by the SPECT. Patients underwent revascularization and thereafter were re-evaluated by the SPECT during a chronic phase, and followed-up to confirm their prognosis for ≥ 1 year. The composite endpoint was the onset of major cardiac events (MCEs) consisting of cardiac death, non-fatal myocardial infarction (MI), unstable angina pectoris (UAP), and severe heart failure requiring hospitalization. The stress phase bandwidth (SPBW) was calculated by phase analysis with the Heart Risk View-F software and its normal upper limit was set to 38°. During the follow-up, 64 patients experienced MCEs: Cardiac death (
n
= 11), non-fatal MI (
n
= 5), UAP (
n
= 26), and severe heart failure (
n
= 22). The results of the multivariate analysis showed the ∆summed difference score %, ∆stress LV ejection fraction, and stress SPBW after revascularization to be independent predictors of MCEs. Additionally, the results of the multivariate logistic regression analysis showed the summed rest score%, summed difference score%, stress LV ejection fraction, and perfusion defects in the left circumflex artery region before revascularization to be independent predictors for normalized SPBW after revascularization. The prognosis of patients who normalized SPBW after revascularization was similar to that of patients with a normal SPBW before revascularization, while patients who did not normalize after revascularization had the worst prognosis. In conclusion, normalization of LV dyssynchrony after revascularization assessed with nuclear cardiology may help predict future MCEs and thus a useful indicator for predicting improved prognosis in patients with CAD.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Objective This retrospective study aimed to investigate the association between therapeutic strategies and the development of major cardiac events (MCEs) in intermediate-risk patients by using the ...J-ACCESS risk model in combination with the stress phase bandwidth (SPBW), an index of left ventricular dyssynchrony. Methods Patients were followed-up for three years to confirm their prognosis. Based on the estimated propensity scores, the patients who underwent revascularization within the first 60 days after SPECT and those who did not were matched 1:1 (n = 367 per group). The composite endpoint was the occurrence of MCEs, consisting of cardiac death, non-fatal myocardial infarction, and severe heart failure. SPBW was calculated by a phase analysis using the Heart Risk View-F software program, and the MCE rate was compared between the two groups by applying the normal value of SPBW (38°). Patients The study included 2,053 patients with either known or suspected CAD who underwent electrocardiogram-gated single-photon emission computed tomography myocardial perfusion imaging and were at intermediate risk of MCE according to the J-ACCESS risk model. Results During follow-up, 54 of the 734 patients (7.4%) experienced MCEs. The overall incidence of MCE in intermediate-risk patients was not significantly different between the two groups. However, the incidence of MCE in patients with an abnormal SPBW was significantly lower in those who underwent early revascularization (4.8% vs. 11.9%, P = 0.0407). Conclusion The combination of the J-ACCESS risk model and the SPBW is thus considered to be an optimal treatment strategy for patients at intermediate risk of MCE, and early revascularization may lead to an improved prognosis in intermediate-risk patients with an abnormal SPBW.
is endemic to human and animal skin and the gastrointestinal tract and is highly tissue-destructive.
bacteremia has a high mortality rate of 20%-30%. A prostatic abscess is a rare complication of ...acute bacterial prostatitis. The focus of
infection is elsewhere in the body, and bacteremia causes the abscess, hence difficult to diagnose. Here, we report a case of prostatic abscesses, followed by a diagnosis of
bacteremia without specific physical findings. The patient was a 72-year-old male with independent activities of daily living who developed prostate and perifemoral abscesses with multiple vague symptoms due to diabetes-related methicillin-susceptible
bacteremia. It is important to comprehensively evaluate multiple vague symptoms considering the immunological conditions of patients and investigate any suspicion of bacteremia and abscess in deep parts of the body. General physicians should be system-specific specialists to deal with multiple symptoms among older immunocompromised patients.
Hypoglycemia is caused by various clinical diseases. Among older patients, occult bacteremia may cause critical illness-related corticosteroid insufficiency (CIRCI), triggering hypoglycemia. ...Additionally, older patients have various chronic medical and homeostatic conditions. Interventions may be needed when chronic conditions cause clinical diseases and CIRCI. Herein, we report a case of possible macrophage activation syndrome (MAS) caused by endoscopic retrograde cholangiopancreatography for bacteremia due to chronic cholelithiasis in an 85-year-old man. Interventions for chronic conditions could impinge on homeostasis in older patients, causing acute conditions such as MAS. Among older frail patients with chronic conditions, interventions for chronic conditions should be discussed, including the triggering of other acute conditions, such as MAS.
In this paper, a stiffness sensor for measuring the softening cubic nonlinear and negative linear stiffness is developed. The measurement system consists of a measurement object, an oscillator and a ...feedback circuit, and achieves the dynamics of van der Pol oscillator by the positive linear velocity feedback and the nonlinear feedback proportional to the squared position and the velocity. Then, the tuning of the nonlinear feedback gain can realize any setting of the magnitude of the response amplitude. Therefore, from the relationship between response amplitudes set by various nonlinear feedback gains and the corresponding response frequencies, we can experimentally describe the backbone curve which exhibits the dependency of the natural frequency on the amplitude in nonlinear mechanical systems. It has been experimentally verified by our research group that the hardening cubic nonlinear and positive linear stiffness can be measured by using the backbone curve. In this research, we assess the potential for measuring the softening cubic nonlinear and negative linear stiffness by employing a magnetic attraction model. The softening cubic nonlinear and negative linear stiffness are also measured by setting the sign of the coefficient of the nonlinear feedback gain appropriately to produce the stable limit cycle.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
PDF
