**Author details**

Vladimir Urosevic1 , Ana Kovacevic2 , Firas Kaddachi3 and Milan Vukicevic4 \*

\*Address all correspondence to<EMAIL_ADDRESS>
1 Belit Ltd., Belgrade, Serbia

2 Big Data Analytics, Belgrade, Serbia

3 Montpellier Laboratory of Informatics, Robotics and Microelectronics (LIRMM), Montpellier, France

4 Faculty of Organizational Sciences, University of Belgrade, Belgrade, Serbia


2.5.3. Antibody-Mediated Rejection Diagnosis

The study from Blydt-Hansen et al. was the only one to specifically evaluate the diagnostic performance for ABMR diagnosis [41]. The authors tested and validated the use of the *ABMR score,* with a good sensitivity (78%) and specificity (83%), NPV of 96%, a good performance (AUC 0.76 in validation), and the ability to provide a stratification from negative—indeterminate—to positive ABMR patients [41].

#### 2.5.4. Acute Rejection, TCMR, and ABMR Prediction

Among prediction studies (Table 5), high risk of bias was often identified for patient selection and index test. However, good performances for AR prediction were obtained by three months post-transplant for CXCL9 and CXCL10 levels [26], and seven days and one month post-transplant for TNF-alpha levels [32]. The well-conducted study by Rabant et al. found both urinary CXCL9 and CXCL10, adjusted for urinary creatinine concentration, to have high NPV (89 to 93%) for AR at one and three months post-transplantation. CXCL10 yielded the best predictive performance (AUC 0.72) at one month post-transplantation, at the threshold of 2.79 ng/mmoL [50]. For TCMR prediction, post-transplant CXCL10 and miR-155-5p levels yielded positive results [34], while for ABMR prediction six months albuminuria was investigated [42].


**5. Tribological Properties**

Inorganic nanoparticles are frequently incorporated into thermoplastic polymers with the aim to improve the tribological properties. The nanoparticles exhibit some advantages compared to conventional microfillers, such as higher specific surface area, lower abrasiveness due to a reduced angularity, enhanced strength, modulus and toughness. In addition, IF-WS2 possess a lubricant character, and have been shown to be effective for improving the tribological properties of thermoplastic polymers such as PPS or PEEK [59,60]. Figure 7 displays the change in the coefficient of friction () and wear rate of PPS/CF upon addition of IF-WS2 [23]. The incorporation of 0.1 wt.% IF-WS2 leads to a slight increase in (~5%) compared to the reference laminate, probably related to the decrease in stiffness and strength found for this sample that prevails over the lubricant effect of the IF-WS2. Further

increasing the nanoparticle loading, drops strongly, reaching the lowest value at 2.0 wt.% IF-WS2 (about 32% drop compared to the reference laminate). Rapoport *et al.* [61] proposed a rolling mechanism for these nanoparticles, in which they act as a ball-bearing component, implying that they roll instead of sliding between the surfaces, hence, decreasing the shear stress, contact temperature and coefficient of friction. Likewise, the abovementioned behavior can be attributed to a synergistic effect between the CFs and the inorganic nanoparticles, as reported previously for CF-reinforced PEEK incorporating ZnS or TiO2 nanoparticles [62].

**Figure 7.** Coefficient of friction and wear rate of PPS/IF-WS2/CF laminates as a function of IF-WS2 content.

With regard to the wear rate, a progressive reduction in this parameter is found upon increasing IF-WS2 concentration, which decreases by nine-fold for the composite with 2.0 wt.% loading compared to the reference laminate. This increase in wear resistance has been attributed to the formation of a thin, continuous, and smooth transfer film on the counterface during sliding combined with the reinforcing effect, and it is enhanced by the presence of the two fillers. The adhesion of the transfer film would be stronger since a homogeneous mixture of the debris is formed, and the resistance to cracking and fatigue failure would also increase in the presence of the nanoparticles. An analogous trend was reported for the wear behavior of PEEK/ZrO2/CF composites [62], where a synergistic effect of CFs with ZrO2 nanoparticles on enhancing the matrix wear resistance was proposed. Overall, the combination of conventional CF-reinforced thermoplastics with lubricant nanoparticles like IF-WS2 is a promising approach to develop multiscale hybrids with superior tribological performance.

**Table 3.** Wear rate (K) data of PP nanocomposites nanocomposites using nanoreinforcing fillers with different morphologies.

Table 3 collects the wear rate of melt-procesable iPP/INT-MoS2 nanocomposites [31]. With the incorporation of INT-MoS2 the wear resistance of the polymer is considerably enhanced and the nanocomposite with 1.0 wt.% loading shows a reduction of about 53%. These inorganic nanotubes dispersed in the polymer matrix can act as a barrier and prevent large-scale fragmentation of the iPP. It has been reported that nanofillers of similar dimensions as the segments of the surrounding polymer chains enable a milder material removal and aid the formation of uniform tenacious transfer film [63,64]. Table 3 also compares the percentage of variations in the wear rate of PP nanocomposites containing 1.0 wt.% of nanoclay [65], IF-WS2 [42], and INT-MoS2 [31]. In particular, PP/INT-MoS2 showed higher wear property improvement than that of PP/nanoclay without the need for an exfoliation process. The highest percentage of improvement in wear rate is found for IF-WS2 solid lubricant nanoparticles, which have recently been identified as ideal candidates for improving the tribological performance of polymers like epoxy [61], nylon-6 [19], and PEEK [18].


**2. CVB3 genome organization and its receptor**

CVB3, a member of enterovirus in the *Picornaviridae* family, is a positive single-stranded, non-enveloped RNA virus. Its genome is ~7.4 kb long containing a single long open reading frame (encoding 11 proteins) flanking by the 5' and 3'untranslated regions (UTRs) (Klump et al., 1990). The 5'UTR is unusually long (741 nucleotides (nt)) and harbors a number of *cis*acting translational elements, such as internal ribosomal entry site (IRES) and cloverleaf sequence (Cheung et al., 2007; Z. Liu et al., 1999; Verma et al., 2010; Yang et al., 1997), which are crucial structures for viral translation and transcription. The 3'UTR is a 99-nt long segment attached with a poly-A tail. The 3'UTR folds to form kissing-loop tertiary structures, which are believed to play a role in facilitating viral transcription of the negative strand of CVB3 replication intermediate (Melchers et al., 1997; J. Wang et al., 1999). The viral genomic RNA can directly serve as a mRNA template for translation of a single long polyprotein, which is processed by viral proteases to produce eleven individual proteins, among which four are structural proteins, VP1-VP4, and seven are non-structural proteins including proteases, 2A and 3C, as well as a RNA-dependent RNA polymerase 3D. These three enzymatic proteins play important roles in viral life cycle and pathogenesis (Knowlton, 2008).

CVB3 is a cardiotropic virus. It infects cardiomyocytes by endocytosis through viral receptor CAR (coxsackie and adenovirus receptor) colocalized with tight junction protein (e.g., occludin) (Raschperger et al., 2006). Structural analysis of CAR D1 domain supports the proposed function of CAR as a mediator of cell adhesion (Honda et al., 2000) in the junction complexes of epithelial cells in many tissues (Cohen et al., 2001). It is also known that CAR binding site (anti-receptor) on CVB3 particle lies in the canyon on the capsid surface. Upon attachment of CVB3 particles to CAR, the receptor changes conformation to form the viral A-particle, a product of the interactions between CVB3 and CAR, which then allows for the release of viral RNA into host cells and begins viral translation and transcription. The observation that soluble CAR can function as a virus trap leading to inactive A-particles has been suggested as a strategy for CVB3 therapy (Pinkert et al., 2009; Werk et al., 2009; Yanagawa et al., 2004). Depending on the different combination of viral strains and mouse models in study of CVB3 infection, a CVB3 co-receptor called decay accelerating factor (DAF, CD55) is sometimes also necessary for CVB3 entry of the host cells (Freimuth et al., 2008; Shafren et al., 1997). Thus, genes encoding CAR and DAF are important candidates for study of viral tropism and rationale targets for antiviral drug design.