Domain-specific cognitive impairment in multiple sclerosis: A systematic review and meta-analysis.

OBJECTIVE: Methods of cognitive measurements in multiple sclerosis (MS) are not standardized. We aimed to identify the prevalence of cognitive domain-specific impairment (DSI) in MS by using subtests of the Brief Repeatable Battery of Neuropsychological Tests (BRB-N) with analyzing different cutoff values. METHODS: The systematic review and meta-analysis were registered on PROSPERO (ID: CRD42021287004). The systematic literature search was performed via PubMed, Embase, and CENTRAL on 24 October 2021. Inclusion criteria were adults of different MS subtypes (CIS, RRMS, PPMS, and SPMS) with the condition of distinct DSI measured by BRB-N. Pediatric MS, computerized versions of BRB-N, and patients receiving steroids were excluded. Primary outcome was pooled prevalence rates of impaired patients within each cutoff and MS subtype, with 95% confidence interval, I-squared statistics for heterogeneity, and chi-squared test for subgroup differences. Risk of bias was assessed using the "JBI Quality Assessment Tool for Prevalence Studies." RESULTS: In 48 eligible observational studies (n = 3431 patients), the three most prevalent thresholds were the 2.0 SD and 1.5 SD below the mean of normative values, and the score below the fifth percentile of the normative values. A progressively increasing worsening of the overall DSI was observed from CIS, moving toward RRMS, PPMS, and SPMS. INTERPRETATION: Cognitive impairment is observed in all MS phenotypes, with varying degrees. Due to several potential influencing factors, our comprehensive literature review has not revealed consistent findings, and we, therefore, recommend considering a more sophisticated, "individual referencing" approach, acknowledging the diverse clinical and sociodemographic characteristics among populations and disparities in cognitive testing.

In Situ Synchrotron Diffraction Analysis of Zn Additions on the Compression Properties of NK30.

In situ synchrotron radiation diffraction was performed during the compression of as-cast Mg-3Nd-Zn alloys with different amounts (0, 0.5, 1, and 2 wt %) of Zn addition at room temperature. During the tests, the acoustic emission signals of the samples were recorded. The results show that the addition of Zn decreased the strength of the alloys but, at the same time, increased their ductility. In the earlier stages of deformation, twin formation and basal slip were the dominant deformation mechanisms. The twins tended to grow during the entire compression stage; however, the formation of new twins dominated only at the beginning of the plastic deformation. In order to accommodate the strain levels, the alloys containing Zn underwent nonbasal slip in the later stages of deformation. This can be attributed to the presence of precipitates containing Zn in the microstructure, inhibiting twin growth.

Comprehensive Evaluation of the Properties of Ultrafine to Nanocrystalline Grade 2 Titanium Wires.

This paper describes the mechanical properties and microstructure of commercially pure titanium (Grade 2) processed with Conform severe plastic deformation (SPD) and rotary swaging techniques. This technology enables ultrafine-grained to nanocrystalline wires to be produced in a continuous process. A comprehensive description is given of those properties which should enable straightforward implementation of the material in medical applications. Conform SPD processing has led to a dramatic refinement of the initial microstructure, producing equiaxed grains already in the first pass. The mean grain size in the transverse direction was 320 nm. Further passes did not lead to any additional appreciable grain refinement. The subsequent rotary swaging caused fine grains to become elongated. A single Conform SPD pass and subsequent rotary swaging resulted in an ultimate strength of 1060 MPa and elongation of 12%. The achieved fatigue limit was 396 MPa. This paper describes the production possibilities of ultrafine to nanocrystalline wires made of pure titanium and points out the possibility of serial production, particularly in medical implants.

Investigation of the Microstructure Evolution and Deformation Mechanisms of a Mg-Zn-Zr-RE Twin-Roll-Cast Magnesium Sheet by In-Situ Experimental Techniques.

Twin roll casting (TRC), with a relatively fast solidification rate, is an excellent production method with promising potential for producing wrought semi or final Mg alloy products that can often suffer from poor formability. We investigate in this study the effect of the TRC method and the subsequent heat treatment on the microstructure and deformation mechanisms in Mg-Zn-Zr-Nd alloy deformed at room temperature using the in-situ neutron diffraction and acoustic emission techniques and ex-situ texture measurement and microscopy, respectively. Although a higher work hardening is observed in the rolling direction due to the more intensive -type dislocation activity, the difference in the mechanical properties of the specimens deformed in the RD and TD directions is small in the as-rolled condition. An additional heat treatment results in recrystallization and significant anisotropy in the deformation. Due to the easier activation of the extension twinning in the TD given by texture, the yield stress in the TD is approximately 40% lower than that in the RD.

Surface-Mediated Energy Transfer and Subsequent Photocatalytic Behavior in Silicon Carbide Colloid Solutions.

We demonstrate that particle-particle interaction affects the photocatalytic efficiency of colloids. Colloid silicon carbide nanoparticles were examined by varying their size, size distribution, and surface chemistry, and we found that surface moieties show no effect on the individual particles but dramatically affect the collective photocatalytic efficiency of the system.

Increasing strength of a biomedical Ti-Nb-Ta-Zr alloy by alloying with Fe, Si and O.

Low-modulus biomedical beta titanium alloys often suffer from low strength which limits their use as load-bearing orthopaedic implants. In this study, twelve different Ti-Nb-Zr-Ta based alloys alloyed with Fe, Si and O additions were prepared by arc melting and hot forging. The lowest elastic modulus (65GPa) was achieved in the benchmark TNTZ alloy consisting only of pure ß phase with low stability due to the 'proximity' to the ß to α'' martensitic transformation. Alloying by Fe and O significantly increased elastic modulus, which correlates with the electrons per atom ratio (e/a). Sufficient amount of Fe/O leads to increased yield stress, increased elongation to fracture and also to work hardening during deformation. A 20% increase in strength and a 20% decrease in the elastic modulus when compared to the common Ti-6Al-4V alloy was achieved in TNTZ-Fe-Si-O alloys, which proved to be suitable for biomedical use due to their favorable mechanical properties.

Substituent effect on the photoreduction kinetics of benzophenone.

The kinetics of the photoreduction of four benzophenone derivatives by isopropyl alcohol was examined in acetonitrile, namely, tetra-meta-trifluoromethyl-, di-para-trifluoromethyl-, di-para-methoxy benzophenone, and, for comparison, the unsubstituted molecule itself. The basic spectroscopic (absorption and phosphorescence spectra) and photophysical (quantum yields and excited state energies) properties were established, and the key kinetic parameters were determined by the laser flash photolysis transient absorption technique. The rate coefficients of both the primary and secondary photoreduction reaction show remarkable dependence on ring substitution. This substantial effect is caused by the considerable change in the activation energy of the corresponding process. The experimental results as well as DFT quantum chemical calculations clearly indicate that these benzophenone derivatives all react as n-π* excited ketones, and the rate as well as the activation energy of the reduction steps change parallel with the reaction enthalpies, the determining factor being the stability of the forming aromatic ketyl radicals. The secondary photoreduction of benzophenones by the aliphatic ketyl radical formed in the primary step occurs via a hydrogen bonded complex. The binding energy of the hydrogen bonded complex between the aliphatic ketyl radical reactant and a solvent molecule is a critical parameter influencing the observable rate of the secondary photoreduction.