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Recent advances in artificial intelligence (AI) present a broad range of possibilities in medical research. However, orthopaedic researchers aiming to participate in research projects implementing AI-based techniques require a sound understanding of the technical fundamentals of this rapidly developing field. Initial sections of this technical primer provide an overview of the general and the more detailed taxonomy of AI methods. Researchers are presented with the technical basics of the most frequently performed machine learning (ML) tasks, such as classification, regression, clustering and dimensionality reduction. Additionally, the spectrum of supervision in ML including the domains of supervised, unsupervised, semisupervised and self-supervised learning will be explored. Recent advances in neural networks (NNs) and deep learning (DL) architectures have rendered them essential tools for the analysis of complex medical data, which warrants a rudimentary technical introduction to orthopaedic researchers. Furthermore, the capability of natural language processing (NLP) to interpret patterns in human language is discussed and may offer several potential applications in medical text classification, patient sentiment analysis and clinical decision support. The technical discussion concludes with the transformative potential of generative AI and large language models (LLMs) on AI research. Consequently, this second article of the series aims to equip orthopaedic researchers with the fundamental technical knowledge required to engage in interdisciplinary collaboration in AI-driven orthopaedic research. Level IV.

Predictions of the mechanical response of polycrystalline metals and underlying microstructure evolution and deformation mechanisms are critically important for the manufacturing and design of metallic components, especially those made of new advanced metals that aim to outperform those in use today. In this review article, recent advancements in modeling deformation processing-microstructure evolution and in microstructure–property relationships of polycrystalline metals are covered. While some notable examples will use standard crystal plasticity models, such as self-consistent and Taylor-type models, the emphasis is placed on more advanced full-field models such as crystal plasticity finite elements and Green’s function-based models. These models allow for nonhomogeneity in the mechanical fields leading to greater insight and predictive capability at the mesoscale. Despite the strides made, it still remains a mesoscale modeling challenge to incorporate in the same model the role of influential microstructural features and the dynamics of underlying mechanisms. The article ends with recommendations for improvements in computational speed.

In this work, the deformation mechanisms underlying the room temperature deformation of the pseudomorphic body centered cubic (BCC) Mg phase in Mg/Nb nanolayered composites are studied. Nanolayered composites comprised of 50% volume fraction of Mg and Nb were synthesized using physical vapor deposition with the individual layer thicknesses h of 5, 6.7, and 50 nm. At the lower layer thicknesses of h = 5 and 6.7 nm, Mg has undergone a phase transition from HCP to BCC such that it formed a coherent interface with the adjoining Nb phase. Micropillar compression testing normal and parallel to the interface plane shows that the BCC Mg nanolayered composite is much stronger and can sustain higher strains to failure than the HCP Mg nanolayered composite. A crystal plasticity model incorporating confined layer slip is presented and applied to link the observed anisotropy and hardening in the deformation response to the underlying slip mechanisms.

Acupuncture and related acupoint therapies have been widely used for smoking cessation. Some relevant systematic reviews (SRs) have been published. There is a need to summarize and update the evidence to inform practice and decision-making. Eight databases were searched from their inception to December 2023. SRs, any randomized controlled trials (RCTs) comparing acupuncture therapies with sham acupuncture, pharmacotherapy, behavioral therapy, or no treatment, were included. The primary outcome was the abstinence rate. AMSTAR-2 was employed to assess the quality of SRs. An updated meta-analysis was conducted based on SRs and RCTs. Data were synthesized using risk ratios (RR) with 95% confidence intervals (CIs). The GRADE approach was employed to assess the certainty of the updated evidence. Thirteen SRs and 20 RCTs outside of the SRs were identified. The SRs were of low or very low quality by AMSTAR-2. Sixteen (80%) RCTs were at high risk of performance bias. Eight acupuncture and related acupoint therapies were involved. The short-term (≤6 months) abstinence rate outcome was summarized as follows. Most SRs suggested that filiform needle acupuncture or acupressure had a better effect than sham acupuncture, but the findings were inconsistent. The updated meta-analysis also suggested that filiform needle acupuncture was more effective than sham acupuncture (RR=1.44; 95% CI: 1.02-2.02; I = 66%; low certainty; 9 RCTs, n=1358). Filiform needle acupuncture combined with acupressure was comparable to nicotine patches (RR=0.99; 95% CI: 0.74-1.32; low certainty; 6 RCTs, n= 524). Acupressure was superior to counseling (RR=1.46; 95% CI: 1.14-1.87; I =5%; low certainty; 8 RCTs, n=595). No serious adverse events were reported in these SRs or RCTs. Low certainty evidence suggests that filiform needle acupuncture and auricular acupressure appear to be safe and effective in achieving short-term smoking cessation. However, long-term follow-up data are needed.

Introduction: COVID-19 (coronavirus disease 2019) was first identified in China in December 2019 and is rapidly spreading worldwide as a pandemic. Since COVID-19 causes mild to severe acute respiratory syndrome, most studies in this context have focused on pathogenesis primarily in the respiratory system. However, evidence shows that the central nervous system (CNS) may also be affected by COVID-19. Since COVID-19 is spreading, it is necessary to study its possible cognitive effects on COVID-19 patients and their recovery. Methods: The articles used in this study were searched by keywords, such as cytokine storm and COVID-19, COVID-19 and executive dysfunction, cognitive disorder, and COVID-19, central nervous system (CNS) and COVID-19, coronavirus, neuroinvasion in Science Direct, Scopus, PubMed, Embase, and Web of Science databases based on preferred reporting items for systematic reviews and meta-analysis (PRISMA) checklist. The study evaluates all observational studies published between December 2019 and April 2021 in peer-reviewed journals, including cross-sectional, cohort, case-control studies, case reports, and case series. The search result was 106 articles, of which 73 articles related to COVID-19, the stages of infection by this virus, its effect on the nervous system and neurological symptoms, the cytokine storm caused by this infection, and the possible cognitive consequences caused by this virus in patients, has been reviewed. Other articles were not checked due to their limited relevance to the topic under discussion. Results: Studies showed that neurons may be directly affected by severe acute respiratory syndrome coronavirus (SARS-CoV)-1 and SARS-CoV-2. Furthermore, various studies indicated that systemic inflammation (so-called “cytokine storm”) is also responsible for brain damage induced by infection with SARS-CoV-1 and SARS-CoV-2. In such a way that these patients showed elevated levels of interleukin (IL-), 6, 8, and 10 and of tumor necrosis factor-alpha (TNF-α) in their blood. Conclusion: Various cognitive defects have been observed following an increased level of cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6, 8. Therefore, due to the increased level of these pro-inflammatory factors in the brains of these patients, cognitive deficits can be expected, which need further investigation.

Most of the core proteins involved in the microRNA (miRNA) pathway in plants have been identified, and almost simultaneously hundreds of miRNA sequences processed in the Arabidopsis sporophyte have been discovered by exploiting next-generation sequencing technologies. However, there is very limited understanding about potentially distinct mechanisms of post-transcriptional regulation between different cell lineages. In this review the focus is on the Arabidopsis male gametophyte (pollen), where the germline differentiates after meiosis giving rise to the male gametes. Based on comparative analysis of miRNAs identified in sperm cells by in-depth sequencing, their possible functions during germ cell specification and beyond fertilization are discussed. In addition, 25 potentially novel miRNAs processed in sperm cells and pollen were identified, as well as enriched variations in the sequence length of known miRNAs, which might indicate subfunctionalization by association with a putative germline-specific Argonaute complex. ARGONAUTE 5 (AGO5), by close homology to AGO1 and localizing preferentially to the sperm cell cytoplasm in mature pollen, may be part of such a complex.

Despite the potential as a promising alternative to CdTe and Cu(In,Ga)Se2, the kesterite compound Cu2ZnSn(S,Se)4 (CZTSSe) presents a critical challenge mainly from its high open-circuit voltage (Voc) deficit. Indeed, the Voc of the record CZTSSe solar cell to date has accounted for only 61% of that calculated by the Shockley–Queisser limit, whose origin can be ascribed to nonradiative recombination from a high density of defects and secondary phases. Therefore, an atomistic understanding and characterization of CZTSSe is highly essential to overcoming the current shortcomings in kesterite. This review discusses the advanced characterization techniques for studying the intrinsic properties of kesterite at a nanometer scale. Moreover, a cation substitution with an ionic mismatch around constituents is recognized as an effective route to address the fundamental limit (i.e., the cationic disorder) in CZTSSe. Here, we review recent studies on a novel chalcogenide Cu2BaSn(S,Se)4 that substitutes Zn with Ba and results in less cationic disordering.

Growth hormone (GH) is a key peptide hormone in the regulation of bone metabolism, through its systemic and paracrine action mediated directly as well as by insulin-like growth factor-1 (IGF-1). Growth hormone exerts pleiotropic effects leading to an increase in linear bone growth, accumulation of bone mineral content and preservation of peak bone mass. Furthermore, it influences protein, lipid, and carbohydrate metabolism.Growth hormone deficiency (GHD) causes a low bone turnover rate leading to reduced bone mineral density (BMD) and increased bone fragility. The results of GH insufficiency are the most pronounced among children as it negatively affects longitudinal bone growth, causing short stature and in adolescents, in whom it hinders the acquisition of peak bone mass. Most studies show that treatment with recombinant human growth hormone (rhGH) in GHD patients could improve BMD and decrease fracture risk. This review aims to summarize the pathophysiology, clinical picture and management of bone complications observed in GHD.

The phytohormone abscisic acid (ABA) plays a central role in plant development and in plant adaptation to both biotic and abiotic stressors. In recent years, knowledge of ABA metabolism and signal transduction has advanced rapidly to provide detailed glimpses of the hormone's activities at the molecular level. Despite this progress, many gaps in understanding have remained, particularly at the early stages of ABA perception by the plant cell. The search for an ABA receptor protein has produced multiple candidates, including GCR2, GTG1, and GTG2, and CHLH. In addition to these candidates, in 2009 several research groups converged on a novel family of Arabidopsis proteins that bind ABA, and thereby interact directly with a class of protein phosphatases that are well known as critical players in ABA signal transduction. The PYR/PYL/RCAR receptor family is homologous to the Bet v 1-fold and START domain proteins. It consists of 14 members, nearly all of which appear capable of participating in an ABA receptor–signal complex that responds to the hormone by activating the transcription of ABA-responsive genes. Evidence is provided here that PYR/PYL/RCAR receptors can also drive the phosphorylation of the slow anion channel SLAC1 to provide a fast and timely response to the ABA signal. Crystallographic studies have vividly shown the mechanics of ABA binding to PYR/PYL/RCAR receptors, presenting a model that bears some resemblance to the binding of gibberellins to GID1 receptors. Since this ABA receptor family is highly conserved in crop species, its discovery is likely to usher a new wave of progress in the elucidation and manipulation of plant stress responses in agricultural settings.