Summary
Background
Magnetic resonance enterography (MRE) has been proposed as a non‐ionising alternative method to computed tomography enterography (CTE). Some studies have directly compared CTE and ...MRE in patients with small bowel Crohn's disease (CD) with variable results.
Aim
To compare the overall diagnostic accuracy in assessing the activity of small bowel and complications.
Methods
MEDLINE, EMBASE and Cochrane databases were searched for studies on the accuracy of MRE and CTE, as compared with a pre‐defined reference standard. Pooled sensitivity, specificity, the weighted area under the curve (AUC), incremental yield (IY) and other diagnostic indices were evaluated.
Results
A total of 290 CD patients from six different studies were analysed. The pooled sensitivity and specificity for MRE in detecting active small bowel CD was 87.9% 95% confidence interval (CI), 81.8–92.5 and 81.2% (95% CI: 71.9–88.4) respectively. The AUC under the summary receiver‐operating characteristic (sROC) of MRE was 0.905 (SEM 0.03, standard error of the mean). Likewise, the pooled sensitivity and specificity of CTE in detecting active small bowel CD was 85.8% (95% CI: 79.2–90.9) and 83.6% (95% CI: 75.3–90.1) with the AUC of 0.898. The AUC of MRE in detecting fistula, stenosis and abscess was 0.936, 0.931 and 0.996, respectively, compared to 0.963, 0.616 and 0.899 of CTE. No statistically significant IY for MRE vs. CTE was found (fixed model, P > 0.05).
Conclusions
Magnetic resonance enterography has a diagnostic effectiveness comparable to computed tomography enterography, thus may serve as a radiation‐free alternative for evaluation of patients with Crohn's disease.
In this paper, the dynamic evolution of precipitates and its influence on the high-temperature mechanical properties of newly developed AFA steels were systematically investigated. At 1023K or above, ...three main types of precipitates, i.e., the B2-NiAl, Laves-Fe2Nb, and δ/σ phases, were formed in the base steel, and the major strengthening medium is Laves-Fe2Nb, which coarsened quickly, leading to undesirable creep properties. Phase competition between the most effective strengthening NbC nanosized precipitates and the Laves-Fe2Nb phase was analyzed, and it was found that adjusting the Nb/C ratio in the steels could enable the precipitation of highly stable, fine NbC particles. In addition, the formation of detrimental σ phases could be suppressed by lowering the Mo and Si content in the alloy. Eventually, a new type of AFA steel consisting of a high density of nanosized NbC particles homogeneously dispersed in the austenitic matrix was successfully developed, and significant enhancement in the creep resistance was achieved due to the effective strengthening resulting from the tiny secondary NbC particles.
Intramuscular fat (IMF) content and fatty acid (FA) composition vary significantly across beef cattle breeds, which play an important role in taste and nutritional value. However, the molecular ...mechanisms underlying these phenotypic differences remain unknown. The present study compared meat quality traits between Yunling cattle and Chinese Simmental cattle. Yunling cattle showed a lower IMF content and proportion of monounsaturated fatty acids (MUFA), as well as higher proportions of saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA), and short-chain fatty acids (sc-FA) in the longissimus dorsi (LD) muscle than Chinese Simmental cattle. To further identify the candidate genes and pathways responsible for these phenotypic differences, the transcriptome of LD muscle from the two breeds were measured using RNA-seq. A total of 1347 differentially expressed genes were identified. The major metabolic pathways that were differentially modulated were lipolysis and glycometabolism. Yunling cattle showed a higher expression of lipolysis genes (ALDH9A1, ACSL5, ACADM, ACAT2, ACOT2) and a lower expression of genes related to glycometabolism (PGM1, GALM, PGM1, GPI, LDHA). This research identified candidate genes and pathways for IMF content and FA composition in the LD muscle of beef cattle, which may facilitate the design of new selection strategies to improve meat quality.
This article reports the surgical resection of clinically benign tumours in the maxillomandibular deep lobe of the parotid gland via sternocleidomastoid muscle–parotid space (SPS) approach. The use ...of maxillary–mandibular planes to subdivide the deep lobe of the parotid gland in order to establish the tumour location and accessibility is introduced. This approach, which does not raise a skin flap, may preserve the superficial lobe. Ten patients with clinically benign tumours in the maxillomandibular deep lobe of the parotid gland were treated via the SPS approach. The patients were followed up for 3–5 years and the surgical outcomes were analysed. All tumours were completely enucleated via the SPS approach with an optimal aesthetic outcome. No permanent facial weakness or tumour recurrence was identified during the 3–5 years of follow-up. The SPS approach to surgical resection is an ideal option for clinically benign tumours in the maxillomandibular deep lobe of the parotid gland and demonstrates good results.
The aggregation behavior and interactions of yak milk protein were investigated after heat treatments. Skim yak milk was heated at temperatures in the range of 65 to 95°C for 10 min. The results ...showed that the whey proteins in yak milk were denatured after heat treatment, especially at temperatures higher than 85°C. Sodium dodecyl sulfate-PAGE analysis indicated that heat treatment induced milk protein denaturation accompanied with aggregation to a certain extent. When the heating temperature was 75 and 85°C, the aggregation behavior of yak milk proteins was almost completely due to the formation of disulfide bonds, whereas denatured α-lactalbumin and β-lactoglobulin interacted with κ-casein. When yak milk was heated at 85 and 95°C, other noncovalent interactions were found between proteins including hydrophobic interactions. The particle size distributions and microstructures demonstrated that the heat stability of yak milk proteins was significantly lowered by heat treatment. When yak milk was heated at 65 and 75°C, no obvious changes were found in the particle size distribution and microstructures in yak milk. When the temperature was 85 and 95°C, the particle size distribution shifted to larger size trend and aggregates were visible in the heated yak milk.
The deformation behaviour of a newly developed alumina-forming austenitic (AFA) stainless steel at elevated temperatures was investigated. It was found that the steady-state data could be well ...described by a stress power law that considered the threshold stress and temperature dependence of the shear modulus and self-diffusion coefficient, suggesting that the deformation of the austenite matrix was controlled by the lattice self-diffusion. The threshold stress was temperature-dependent and appeared to be caused by Orowan bowing stress. At temperatures below 1023K, the secondary NbC phase was the major hardening precipitate, but at temperatures above 1023K, the Laves Fe2Nb phase became dominant. The apparent interaction energy required for mobile dislocations to overcome the particle obstacles decreased from 163 to 34kJ/mol with increasing temperature, which was most likely associated with the formation of the two different precipitates.
Microscopic pore structure and water distribution are important and fundamental parameters for coalbed methane reservoir characterisation. These are closely related to the calculation/interpretation ...of other critical parameters, such as permeability and flow capacity. In this study, scanning electron microscopy, low-pressure nitrogen gas adsorption, nuclear magnetic resonance spectroscopy, and theoretical calculations were used to study the pore structure characteristics and water distribution of Zhaozhuang coal mine in the southeastern Qinshui Basin, PR China. The results show that the pore radius ranges from 2.066 to 594.045 nm, mainly classified as micropores and transitional pores. The micropores significantly contribute to the total pore volume. The adsorption pores (micropores and transitional pores) contribute the most to the total specific surface area. The T
2
spectrum distributions of saturated water samples show two peaks. The first T
2
spectrum peak is related to adsorption pores, whereas the second T
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spectrum peak is related to seepage pores. The seepage pores were not well developed as the adsorption pores. Most adsorption pores are saturated with irreducible water that could not be discharged by centrifugation, whereas the seepage pores are saturated with movable water that could be completely discharged by centrifugation. The T
2
cutoff method was used to calculate the irreducible water saturation, and the irreducible water saturation of the sample was ≥90%. The irreducible water was mainly distributed in the micropores, and some of the irreducible water was distributed in the transitional pores. The irreducible water that remains in the pores can cause reservoir damage.
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