A new functionally based kinetic model for enzymatic hydrolysis of pure cellulose by the Trichoderma cellulase system is presented. The model represents the actions of cellobiohydrolases I, ...cellobiohydrolase II, and endoglucanase I; and incorporates two measurable and physically interpretable substrate parameters: the degree of polymerization (DP) and the fraction of beta-glucosidic bonds accessible to cellulase, F(a) (Zhang and Lynd, 2004). Initial enzyme-limited reaction rates simulated by the model are consistent with several important behaviors reported in the literature, including the effects of substrate characteristics on exoglucanase and endoglucanase activities; the degree of endo/exoglucanase synergy; the endoglucanase partition coefficient on hydrolysis rates; and enzyme loading on relative reaction rates for different substrates. This is the first cellulase kinetic model involving a single set of kinetic parameters that is successfully applied to a variety of cellulosic substrates, and the first that describes more than one behavior associated with enzymatic hydrolysis. The model has potential utility for data accommodation and design of industrial processes, structuring, testing, and extending understanding of cellulase enzyme systems when experimental date are available, and providing guidance for functional design of cellulase systems at a molecular scale. Opportunities to further refine cellulase kinetic models are discussed, including parameters that would benefit from further study.
► ZnO thin films grown on Si(1
1
1) substrates by ALD and followed by RTA. ► XRD shows that the annealed ZnO films had a predominant (0
0
2) orientation. ► PL show manifest enhanced in intrinsic band ...edge UV emission of annealed ZnO films. ► Hardness of annealed ZnO films follows satisfactorily with the Hall–Petch equation.
ZnO thin films grown on Si(1
1
1) substrates by using atomic layer deposition (ALD) were annealed at the temperatures ranging from 300 to 500
°C. The X-ray diffraction (XRD) results show that the annealed ZnO thin films are highly (0
0
2)-oriented, indicating a well ordered microstructure. The film surface examined by the atomic force microscopy (AFM), however, indicated that the roughness increases with increasing annealing temperature. The photoluminescence (PL) spectrum showed that the intensity of UV emission was strongest for films annealed at 500
°C. The mechanical properties of the resultant ZnO thin films investigated by nanoindentation reveal that the hardness decreases from 9.2
GPa to 7.2
GPa for films annealed at 300
°C and 500
°C, respectively. On the other hand, the Young's modulus for the former is 168.6
GPa as compared to a value of 139.5
GPa for the latter. Moreover, the relationship between the hardness and film grain size appear to follow closely with the Hall–Petch equation.
Structure and piezoelectric coefficient (d33) of lead‐free 7.5% mole BaTiO3‐doped (Bi0.5Na0.5) TiO3 (BNT‐7.5%BT) polycrystalline piezoceramics have been characterized systematically as a function of ...poling electric (E) field. Dielectric permittivity and loss were also measured as functions of frequency and temperature. The piezoelectric coefficient d33 after poling at E = 35 kV/cm can reach d33~186 pC/N, which is the highest value reported among (1−x) BNT–xBT compositions. A prior poling E field can reduce rhomobherdal lattice distortion, and enhance tetragonal phase and polarization ordering, that contribute significantly to the rapid raise of d33 and lower depolarizing temperature (Td). The reduced dielectric permittivity for the poled sample is attributed to ordered state and the pinning of field‐induced nanodomain walls by the presence of oxygen vacancies.
A nanocomposite of polypyrrole/carbon nanotubes prepared by in situ chemical polymerization shows improved conductivity of the polypyrrole as compared with its pure form. Its application as a ...chemical sensor, made using a simple spin‐casting technique, shows a drastically increased sensitivity. The Figure shows a field‐emission scanning electron microscopy (FE‐SEM) image of the SWNT/Ppy nanocomposite.
The efficacy and safety of axitinib, a potent and selective vascular endothelial growth factor receptors 1–3 inhibitor, combined with best supportive care (BSC) was evaluated in a global, randomized, ...placebo-controlled phase II trial in patients with locally advanced or metastatic hepatocellular carcinoma (HCC).
Patients with HCC and Child–Pugh Class A who progressed on or were intolerant to one prior antiangiogenic therapy were stratified by tumour invasion (presence/absence of extrahepatic spread and/or vascular invasion) and region (Asian/non-Asian) and randomized (2:1) to axitinib/BSC (starting dose 5 mg twice-daily) or placebo/BSC. The primary end point was overall survival (OS).
The estimated hazard ratio for OS was 0.907 95% confidence interval (CI) 0.646–1.274; one-sided stratified P = 0.287 for axitinib/BSC (n = 134) versus placebo/BSC (n = 68), with the median (95% CI) of 12.7 (10.2–14.9) versus 9.7 (5.9–11.8) months, respectively. Results of prespecified subgroup analyses in Asian versus non-Asian patients or presence versus absence of tumour invasion were consistent with the overall population. Improvements favouring axitinib/BSC (P < 0.01) were observed in secondary efficacy end point analyses progression-free survival (PFS), time to tumour progression (TTP), and clinical benefit rate (CBR), and were retained among Asian patients in the prespecified subgroup analyses. Overall response rate did not differ significantly between treatments and patient-reported outcomes favoured placebo/BSC. Most common all-causality adverse events with axitinib/BSC were diarrhoea (54%), hypertension (54%), and decreased appetite (47%). Baseline serum analyses identified potential new prognostic (interleukin-6, E-selectin, interleukin-8, angiopoietin-2, migration inhibitory factor, and c-MET) or predictive (E-selectin and stromal-derived factor-1) factors for survival.
Axitinib/BSC did not improve OS over placebo/BSC in the overall population or in stratification subgroups. However, axitinib/BSC resulted in significantly longer PFS and TTP and higher CBR, with acceptable toxicity in patients with advanced HCC.
ClinicalTrials.gov, NCT01210495.
Objectives
This study investigated the association between bone mineral density (BMD) and periodontitis in a representative sample of Korean adults.
Material and Methods
Of 36 188 individuals who ...participated in the Korea National Health and Nutrition Examination Survey in 2008, 2009, and 2010, 9977 participants aged ≥40 years were included in this cross‐sectional study. The associations of BMD of lumbar spine, total femur, and femoral neck with periodontitis were investigated using logistic regression analysis. Additionally, dose–response relationships with BMD divided into quintiles and the association between osteoporosis and periodontitis were investigated.
Results
With the set of Community Periodontal Index (CPI) ≥ 3 as a dependent variable, logistic regression analysis revealed that a decrease of BMD was significantly associated with higher odds of periodontitis range of adjusted odds ratios (AORs); 1.15–1.20, P < 0.001 for all BMD sites. Similarly, these associations were also found in the CPI 4 model. With regard to dose–response relations, the lower the BMD quintile, the higher the AORs appeared with statistical significance in the CPI ≥ 3 model. (P for trend < 0.001) Participants with osteoporosis had 2.26 and 1.91 times higher odds for CPI ≥ 3 and CPI 4, respectively, than those with normal BMD, indicating a significant association between the two diseases.
Conclusions
Our results suggest that BMD is significantly associated with periodontitis.
The proper interval for repeating an interferon-γ release assay (IGRA) among tuberculosis contacts with initially negative results is unknown. The interval for IGRA conversion after exposure to ...patients with active pulmonary tuberculosis in an outbreak setting was evaluated. In a platoon of 32 soldiers, four active pulmonary tuberculosis patients, in addition to one index patient, were diagnosed during a contact investigation. For the other 27 contacts, a tuberculin skin test (TST) and QuantiFERON® TB-Gold In-Tube (QFT-GIT) assay were performed. For soldiers with a negative result on the initial QFT-GIT assay, the test was repeated at 2, 4, 8, 14, 18 and 30 weeks until positive conversion occurred. When conversion was identified, the subject was treated for latent tuberculosis infection. Initially, 17 (63.0%) soldiers gave positive QFT-GIT results, whereas 21 (77.8%) showed positive TST results. Among 10 participants with initially negative QFT-GIT results, three showed conversion at 2 weeks, three at 4 weeks and three at 14 weeks. Conversion did not occur during the 30-week observation period in one contact. Based on the tuberculosis exposure time-points among the contacts, IGRA conversion generally occurred 4-7 weeks after exposure, although it could occur as late as 14-22 weeks after exposure.
Abstract
Background
Bodyweight variability is a risk factor for atrial fibrillation (AF). We aimed to examine the relationship between bodyweight variability and the risk of AF in patients with type ...2 diabetes mellitus (DM), and whether this relationship was affected by baseline body mass index (BMI), weight change, or advanced diabetic stage.
Methods
A nationwide population-based cohort of 670,797 patients with type 2 DM from the Korean National Health Insurance Service database without a history of AF and with ≥ 3 measurements of bodyweight over a 5-year period were followed up for AF development. Intra-individual bodyweight variability was calculated using variability independent of mean, and high bodyweight variability was defined as the quintile with the highest variability with the lower four quintiles as reference.
Results
During a median of 7.0 years of follow-up, 22,019 patients (3.3%) newly developed AF. After multivariate adjustment, those in the highest quintile of bodyweight variability showed a higher risk of incident AF (HR 1.16, 95% CI 1.12–1.20) compared to those in the lower 4 quintiles with reference bodyweight variability, irrespective of baseline BMI group and direction of overall weight change. This association was greater in magnitude in subjects with lower BMI, those on insulin, and those with a DM duration of greater than 5 years. In sensitivity analyses, high bodyweight variability was consistently associated with AF development using other indices of variability and adjusting for glycemic variability.
Conclusions
High variability in bodyweight was associated with AF development, independently of traditional cardiovascular risk factors and baseline BMI. This association was stronger in underweight patients and with advanced diabetic stage. Weight fluctuation may interfere with the beneficial effects of weight loss and should be avoided when possible in weight control regimens for DM patients.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background
High‐resolution manometry using the Chicago classification, which utilizes parameters including integrated relaxation pressure (IRP), distal contractile integral (DCI), and contractile ...front velocity (CFV), shows better diagnostic ability than previous conventional criteria. However, the current normal cut‐off values for the Chicago classification are based on individuals aged 19–48 years and do not include older people. Here, we aimed to assess the normal values for the Chicago classification in individuals aged 20–67 years and compare the parameters across age groups.
Methods
Fifty‐four asymptomatic healthy individuals (27 male and 27 female; age range. 20–67 years) were prospectively enrolled. To evaluate the effect of age and sex on manometric profiles, we attempted to enroll equal numbers of male and female subjects for each decade. Manometry was performed in both the supine and sitting positions.
Key Results
The distal latency (DL) was significantly shorter with increasing age in both measurement positions. Furthermore, IRP was significantly higher with increasing age in both positions. Spearman's ranked correlation coefficient analysis indicated that DCI and IRP in both positions were positively correlated with age.
Conclusions & Inferences
Age affects the key parameters currently used in the Chicago classification, including IRP, DCI, and DL. Larger prospective studies with older subjects are needed to determine the age‐related normal values for the Chicago classification system.
Increasing age can significantly affect the key parameters of the Chicago classification system, especially integrated relaxation pressure, distal contractile integral, and distal latency. The manometric profiles of elderly people should therefore be interpreted with caution.
We construct a deep neural network to enhance the resolution of spin structure images formed by spontaneous symmetry breaking in the magnetic systems. Through the deep neural network, an image is ...expanded to a super-resolution image and reduced to the original image size to be fitted with the input feed image. The network does not require ground truth images in the training process. Therefore, it can be applied when low-resolution images are provided as training datasets, while high-resolution images are not obtainable due to the intrinsic limitation of microscope techniques. To show the usefulness of the network, we train the network with two types of simulated magnetic structure images; one is from self-organized maze patterns made of chiral magnetic structures, and the other is from magnetic domains separated by walls that are topological defects of the system. The network successfully generates high-resolution images highly correlated with the exact solutions in both cases. To investigate the effectiveness and the differences between datasets, we study the network's noise tolerance and compare the networks' reliabilities. The network is applied with experimental data obtained by magneto-optical Kerr effect microscopy and spin-polarized low-energy electron microscopy.
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