The growing popularity and frequency of Internet use has resulted in a large number of studies reporting various clinical problems associated with its abuse. The main purpose of this study is to ...conduct a meta-analysis of the association between Internet addiction (IA) and a number of personal and social psychological factors in adolescents.
The search included cross-sectional, case-control and cohort studies which analyzed the relationship between IA and at least one of the following personal variables: (i) psychopathology, (ii) personality features and (iii) social difficulties, as well as (iv) self-esteem, (v) social skills and (vi) positive family functioning. These variables were classified as protective and promoting factors of the risk of developing IA.
A total of 28 studies with adequate methodological quality were identified in the primary medical, health and psychological literature databases up to November 2017. Of the 48,090 students included in the analysis, 6548 (13.62%) were identified as excessive Internet users. The results highlight that risk factors had a greater effect on IA than protective factors. Also, personal factors showed a greater link with IA than social factors.
The data provide relevant information for those developing programs for the prevention of IA and the enhancement of protective factors.
•Internet addiction (IA) was associated with psychosocial factors in adolescents.•The risk factors had a greater effect on IA than protective factors.•Personal factors showed a greater association with IA than social factors.•Hostility, depression and anxiety showed the greatest link with IA.
Summary
Background A majority of studies investigating the accuracy of ultrasound for detecting hepatocellular carcinoma (HCC) do not reflect how this test is used for surveillance vs. diagnosis.
...Aim To determine the performance characteristics of surveillance with ultrasound for the detection of HCC, particularly early HCC as defined by the Milan criteria.
Methods A systematic literature review using the MEDLINE and SCOPUS databases yielded six studies that evaluated the accuracy of ultrasound for HCC at any stage and 13 studies that were specific to early HCC.
Results Surveillance ultrasound detected the majority of tumours before they presented clinically, with a pooled sensitivity of 94%. However, ultrasound was less effective for detecting early HCC with a sensitivity of 63%. Alpha‐fetoprotein provided no additional benefit to ultrasound. Meta‐regression analysis demonstrated a significantly higher sensitivity for early HCC with ultrasound every 6 months than with annual surveillance. Current studies have limitations such as verification bias and are of suboptimal quality.
Conclusions Surveillance with ultrasound demonstrates limited sensitivity for early HCC, although this may be improved by testing at 6‐month intervals. Currently available evidence evaluating surveillance ultrasound has significant limitations and future studies are necessary to determine optimal surveillance methods for early HCC.
A fast and reliable numerical solver is proposed to handle determined opposite-bordered tridiagonal linear systems Ax=b. A precise sequence of Givens rotations on the nonsingular matrix coefficient A ...allows us to work with a simpler linear system. This equivalent system, which admits always a trivial LU factorization, can be solved in linear time. For large-order matrices of use in applications, the main advantage of this solver with respect to other special algorithms proposed is its stability and risk-free performance, as it is checked with comparative examples. Its extension to manage opposite-bordered tridiagonal matrix equations is straightforward.
A linear-time solver with total flop count 10n−11 and 4n+2 of memory space is introduced for solving determined comrade linear systems of degree n. This algorithm is based on a suitable factorization ...satisfied for every matrix coefficient. It performs faster than other specialized linear-time solvers proposed recently. Contrary speedup, its stability (and that of those specialized from the literature) for large-order comrade systems is not guaranteed. To overcome such weakness, an adapted solver is then proposed running in linear time and 7n+O(1) of memory space. It takes advantage of the inexpensive Givens reduction of the transpose of any comrade matrix and covering also linear systems involving matrices with comrade structure. The results are thoroughly illustrated with proper numerical comparisons.
•IBV-QX vaccine and virulent progenitor have comparable RNA titers in the trachea.•IBV-QX vaccine shows delayed induction of lesions in the respiratory tract.•IBV-QX vaccine has reduced ability to ...disseminate from the site of inoculation to other target tissues.•IBV-QX vaccine displays no nephropathogenicity in SPF broilers.•Ascending virus transport seems to contribute to kidney infection.
Infectious bronchitis (IB) is a highly contagious respiratory disease of poultry, caused by the avian coronavirus infectious bronchitis virus (IBV). Currently, one of the most relevant genotypes circulating worldwide is IBV-QX (GI-19), for which vaccines have been developed by passaging virulent QX strains in embryonated chicken eggs. Here we explored the attenuated phenotype of a commercially available QX live vaccine, IB Primo QX, in specific pathogens free broilers. At hatch, birds were inoculated with QX vaccine or its virulent progenitor IBV-D388, and postmortem swabs and tissues were collected each day up to eight days post infection to assess viral replication and morphological changes. In the trachea, viral RNA replication and protein expression were comparable in both groups. Both viruses induced morphologically comparable lesions in the trachea, albeit with a short delay in the vaccinated birds. In contrast, in the kidney, QX vaccine viral RNA was nearly absent, which coincided with the lack of any morphological changes in this organ. This was in contrast to high viral RNA titers and abundant lesions in the kidney after IBV D388 infection. Furthermore, QX vaccine showed reduced ability to reach and replicate in conjunctivae and intestines including cloaca, resulting in significantly lower titers and delayed protein expression, respectively. Nephropathogenic IBVs might reach the kidney also via an ascending route from the cloaca, based on our observation that viral RNA was detected in the cloaca one day before detection in the kidney. In the kidney distal tubular segments, collecting ducts and ureter were positive for viral antigen. Taken together, the attenuated phenotype of QX vaccine seems to rely on slower dissemination and lower replication in target tissues other than the site of inoculation.
To overcome several limitations of symbolic algorithms introduced recently for matrices of large order, a fast numerical solver is proposed for the matrix linear equation AX=B, where the n×n ...coefficient matrix A is a general nonsingular bordered tridiagonal matrix. Its sparse structure is preserved through partial Givens reduction. In particular, the matrix inverse of A can be computed. For a wide range of bordered tridiagonal linear systems Ax=b, the solution is computed in linear time using back substitution and Sherman–Morrison’s formula. Numerical comparisons illustrate the results.
Summary
Background
Abdominal ultrasound fails to detect over one‐fourth of hepatocellular carcinoma (HCC) at an early stage in patients with cirrhosis. Identifying patients in whom ultrasound is of ...inadequate quality can inform interventions to improve surveillance effectiveness.
Aim
To evaluate and identify predictors of ultrasound quality in patients with cirrhosis.
Methods
We performed a retrospective cohort study among patients who underwent ultrasound examination for a cirrhosis‐related indication between April 2015 and October 2015. Three fellowship‐trained abdominal radiologists collectively reviewed all ultrasound exams and categorised exam quality as definitely adequate, likely adequate, likely inadequate and definitely inadequate to exclude liver lesions. We performed multivariable logistic regression to determine characteristics associated with inadequate ultrasound quality.
Results
Among 941 patients, 191 (20.3%) ultrasounds were inadequate for excluding HCC‐ 134 definitely inadequate and 57 likely inadequate. In multivariable analysis, inadequate quality was associated with male gender (OR 1.68, 95% CI 1.14–2.48), body mass index category (OR 1.67, 95% CI 1.45–1.93), Child–Pugh B or C cirrhosis (OR 1.93, 95% CI 1.32–2.81), alcohol‐related cirrhosis (OR 2.11, 95% CI 1.33–3.37), NASH cirrhosis (OR 2.87, 95% CI 1.71–4.80), and in‐patient status (OR 1.55, 95% CI 1.01–2.37). Ultrasounds were inadequate in over one‐third of patients with Child–Pugh C cirrhosis, BMI >35, or NASH cirrhosis.
Conclusions
One in five ultrasounds in patients with cirrhosis are inadequate for exclusion of HCC, which can contribute to surveillance failure. Alternative surveillance modalities are needed in subgroups prone to inadequate ultrasounds including obese patients, those with Child Pugh B or C cirrhosis, and those with alcohol‐ or NASH‐related cirrhosis.
Linked Content
This article is linked to Simmons et al and Patel papers. To view these articles visit https://doi.org/10.1111/apt.13910 and https://doi.org/10.1111/apt.13891.
Biomining of sulfidic ores has been applied for almost five decades. However, the bioprocessing of oxide ores such as laterites lags commercially behind. Recently, the Ferredox process was proposed ...to treat limonitic laterite ores by means of anaerobic reductive dissolution (AnRD), which was found to be more effective than aerobic bioleaching by fungi and other bacteria. We show here that the ferric iron reduction mediated by Acidithiobacillus thiooxidans can be applied to an aerobic reductive dissolution (AeRD) of nickel laterite tailings. AeRD using a consortium of Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans extracted similar amounts of nickel (53–57%) and cobalt (55–60%) in only 7 days as AnRD using Acidithiobacillus ferrooxidans. The economic and environmental advantages of AeRD for processing of laterite tailings comprise no requirement for an anoxic atmosphere, 1.8-fold less acid consumption than for AnRD, as well as nickel and cobalt recovered in a ferrous-based pregnant leach solution (PLS), facilitating the subsequent metal recovery. In addition, an aerobic acid regeneration stage is proposed. Therefore, AeRD process development can be considered as environmentally friendly for treating laterites with low operational costs and as an attractive alternative to AnRD.
An AA6082 alloy deformed by equal channel angular pressing (ECAP) was studied. Microstructural evolution of the alloy processed by ECAP with different passes were evaluated by using optical ...microscope, scanning electron microscopy coupled with an electron backscattered diffraction (EBSD) detector and X-ray diffraction. Texture analysis showed the apparition of two types of textures, one associated with shearing deformation and the second due to the recrystallization phenomena. Mechanical strength properties measured by tensile tests increased in the first ECAP pass, and then progressively diminished due to the presence of concurrent softening phenomena. Calorimetric analysis indicated a slightly increase in the recrystallization temperature of the deformed specimens. Also, the stored energy increased with increasing ECAP passes due to the production of new dislocations. The average geometrically necessary dislocation density, measured by EBSD, increased with increasing ECAP passes. However, the rate of increase slows down with the progress of ECAP passes.
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