Quantum Dots on a String: In Situ Observation of Branching and Reinforcement Mechanism of Electrospun Fibers

Immobilization of quantum dots (QDs) on fiber surfaces has emerged as a robust approach for preserving their functional characteristics while mitigating aggregation and instability issues. Despite the advancement, understanding the impacts of QDs on jet-fiber evolution during electrospinning, QDs-fiber interface, and composites functional behavior remains a knowledge gap. The study adopts a high-speed imaging methodology to capture the immobilization effects on the QDs-fiber matrix. In situ observations reveal irregular triangular branches within the QDs-fiber matrix, exhibiting distinctive rotations within a rapid timeframe of 0.00667 ms. The influence of FeQDs on Taylor cone dynamics and subsequent fiber branching velocities is elucidated. Synthesis phenomena are correlated with QD-fiber's morphology, crystallinity, and functional properties. PAN-FeQDs composite fibers substantially reduced (50-70%) nano-fibrillar length and width while their diameter expanded by 17%. A 30% enhancement in elastic modulus and reduction in adhesion force for PAN-FeQDs fibers is observed. These changes are attributed to chemical and physical intertwining between the FeQDs and the polymer matrix, bolstered by the shifts in the position of C≡N and C═C bonds. This study provides valuable insights into the quantum dot-fiber composites by comprehensively integrating and bridging jet-fiber transformation, fiber structure, nanomechanics, and surface chemistry.

Improving the development of human engineered cardiac tissue by gold nanorods embedded extracellular matrix for long-term viability

A myocardial infarction (MI), commonly called a heart attack, results in the death of cardiomyocytes (CMs) in the heart. Tissue engineering provides a promising strategy for the treatment of MI, but the maturation of human engineered cardiac tissue (hECT) still requires improvement. Conductive polymers and nanomaterials have been incorporated into the extracellular matrix to enhance the mechanical and electrical coupling between cardiac cells. Here we report a simple approach to incorporate gold nanorods (GNRs) into the fibrin hydrogel to form a GNR-fibrin matrix, which is used as the major component of the extracellular matrix for forming a 3D hECT construct suspended between two flexible posts. The hECTs made with GNR-fibrin hydrogel showed markers of maturation such as higher twitch force, synchronous beating activity, sarcomere maturation and alignment, t-tubule network development, and calcium handling improvement. Most importantly, the GNR-hECTs can survive over 9 months. We envision that the hECT with GNRs holds the potential to restore the functionality of the infarcted heart.

Freeze casting to engineer gradient porosity in hydroxyapatite-boron nitride nanotube composite scaffold for improved compressive strength and osteogenic potential

Graded porosity plays a crucial role in scaffolds for bone tissue engineering as it facilitates vital processes such as nutrient diffusion, cellular infiltration, and tissue integration. This paper explores the utilization of freeze casting (FC) as a technique to generate composite scaffolds comprising hydroxyapatite (HA) reinforced with 1D-boron nitride nanotubes (BNNTs) featuring graded porosity and improved compressive strength. Comparative studies were conducted using FC at room and sub-zero temperatures to assess the influence of temperature gradient and heat transfer rate on the production of gradient and aligned porosity in HA-BNNT composites. The FC process with a prolonged thermal gradient facilitated the creation of aligned pores in the HA-BNNT, exhibiting a wide distribution of 60% porosity ranging from 1 to 30 μm. Adding high strength 1 vol% BNNT reinforcement resulted in a remarkable 50% enhancement in compressive strength compared to the control sample. Osteoblasts seeded on the HA-BNNT substrate exhibited significantly higher alkaline phosphate activity, indicating accelerated mineralization compared to the control sample. Gradient porosity and wide pore distribution in the HA-BNNT scaffolds promoted osteogenic activities. Overall, the demonstrated FC processing technique and BNNT addition hold great potential for developing functional and biomimetic scaffolds that can effectively promote tissue regeneration, leading to improved clinical outcomes in bone tissue engineering applications.

Clonal hematopoiesis related TET2 loss-of-function impedes IL1β-mediated epigenetic reprogramming in hematopoietic stem and progenitor cells

Clonal hematopoiesis (CH) is defined as a single hematopoietic stem/progenitor cell (HSPC) gaining selective advantage over a broader range of HSPCs. When linked to somatic mutations in myeloid malignancy-associated genes, such as TET2-mediated clonal hematopoiesis of indeterminate potential or CHIP, it represents increased risk for hematological malignancies and cardiovascular disease. IL1β is elevated in patients with CHIP, however, its effect is not well understood. Here we show that IL1β promotes expansion of pro-inflammatory monocytes/macrophages, coinciding with a failure in the demethylation of lymphoid and erythroid lineage associated enhancers and transcription factor binding sites, in a mouse model of CHIP with hematopoietic-cell-specific deletion of Tet2. DNA-methylation is significantly lost in wild type HSPCs upon IL1β administration, which is resisted by Tet2-deficient HSPCs, and thus IL1β enhances the self-renewing ability of Tet2-deficient HSPCs by upregulating genes associated with self-renewal and by resisting demethylation of transcription factor binding sites related to terminal differentiation. Using aged mouse models and human progenitors, we demonstrate that targeting IL1 signaling could represent an early intervention strategy in preleukemic disorders. In summary, our results show that Tet2 is an important mediator of an IL1β-promoted epigenetic program to maintain the fine balance between self-renewal and lineage differentiation during hematopoiesis.

Effects of Deposition Temperature and Working Pressure on the Thermal and Nanomechanical Performances of Stoichiometric Cu3N: An Adaptable Material for Photovoltaic Applications

The pursuit of efficient, profitable, and ecofriendly materials has defined solar cell research from its inception to today. Some materials, such as copper nitride (Cu3N), show great promise for promoting sustainable solar technologies. This study employed reactive radio-frequency magnetron sputtering using a pure nitrogen environment to fabricate quality Cu3N thin films to evaluate how both temperature and gas working pressure affect their solar absorption capabilities. Several characterization techniques, including X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS), Raman spectroscopy, scanning electron microscopy (SEM), nanoindentation, and photothermal deflection spectroscopy (PDS), were used to determine the main properties of the thin films. The results indicated that, at room temperature, it is possible to obtain a material that is close to stoichiometric Cu3N material (Cu/N ratio ≈ 3) with (100) preferred orientation, which was lost as the substrate temperature increases, demonstrating a clear influence of this parameter on the film structure attributed to nitrogen re-emission at higher temperatures. Raman microscopy confirmed the formation of Cu-N bonds within the 628-637 cm-1 range. In addition, the temperature and the working pressure significantly also influence the film hardness and the grain size, affecting the elastic modulus. Finally, the optical properties revealed suitable properties at lower temperatures, including bandgap values, refractive index, and Urbach energy. These findings underscore the potential of Cu3N thin films in solar energy due to their advantageous properties and resilience against defects. This research paves the way for future advancements in efficient and sustainable solar technologies.

Update from the 5th Edition of the WHO Classification of Nasal, Paranasal, and Skull Base Tumors: Imaging Overview with Histopathologic and Genetic Correlation

Sinonasal and skull base tumors are a heterogeneous group of neoplasms with considerable histologic variation and overlapping imaging features. In 2022, the World Health Organization updated the head and neck tumor classification, further emphasizing the importance of molecular data and genetic alterations in sinonasal neoplasms. The changes include the addition of new entities and discussion of emerging entities, as well as changes to the taxonomy and characterization of tumors. The new classification focuses on entities that develop in these sites either exclusively (eg, olfactory neuroblastoma) or most frequently. Another change includes reduction in the number of categories by creating separate category-specific chapters for soft-tissue, hematolymphoid, and neuroectodermal lesions. In this review, we briefly discuss the various categories in the new classification with a more detailed description of the 2 new entities (SWItch/Sucrose Non-Fermentable complex-deficient sinonasal carcinomas and human papillomavirus-related multiphenotypic sinonasal carcinoma). We also highlight the emerging entities including IDH-mutant sinonasal malignancies and DEK-AFF2 carcinoma, presently classified as sinonasal undifferentiated carcinoma and nonkeratinizing squamous cell carcinoma, respectively.

Comparative efficacy of Micropore™ surgical dressing, Tegaderm™ and Lockit plus® for lumbar epidural catheter fixation in children: a prospective parallel group randomized controlled trial

BACKGROUND

Proper fixation of an epidural catheter is necessary for desired drug effect and to prevent catheter displacement. Different techniques have been used for epidural catheter fixation. The aim of the study was to compare the relative efficacy of Micropore™ surgical dressing, Tegaderm™, and Lockit plus® in preventing lumbar epidural catheter migration in children.

METHODS

We studied 167 patients aged 5-16 years, for up to 48 h. After the elective abdominal or lower limb surgery. Patients were randomly assigned to one of three groups: (1) Micropore™ surgical dressing (group M), (2) Tegaderm™ (group T), or (3) Lockit plus® (group L). Incidence and extent of epidural catheter migration in centimetres (cm); was compared at 24 and 48 h post epidural fixation. Correlation between epidural catheter migration and patient characteristics, and relative incidence of complications in three groups was also analysed.

RESULTS

Incidence of catheter migration was 9.6% at 24 h (group M: 7.1%, group T: 21.1% and group L: 0%) and 45.5% at 48 h (group M: 66.1%, group T: 45.6% and group L: 24.1%). After 48 h, absolute migration (mean migration rounded off to the nearest 0.5 cm) was least in patients in group L: 0.34 cm (1.39) compared to group M 1.22 cm (SD: 1.85) group T: 0.94 cm (1.94) (p = <0.001).

CONCLUSION

Up to 48 h after surgery, the Lockit plus® device demonstrated the less epidural catheter migration when compared to micropore surgical dressing or tegaderm in children undergoing elective abdominal or lower limb surgery.

Unpacking the CNS Manifestations of Epstein-Barr Virus: An Imaging Perspective

Epstein-Barr virus is a ubiquitous herpesvirus that may cause both infective (encephalitis, meningitis, and so forth) and postinfection inflammatory (such as Guillain-Barré syndrome, acute disseminated encephalomyelitis) manifestations in the CNS. Diagnosis of Epstein-Barr virus-related CNS pathologies is often complicated due to a nonspecific clinical presentation and overlap with other infectious and noninfectious causes, both clinically and on imaging. The Epstein-Barr virus is also implicated in several lymphoproliferative disorders in both immunocompromised and immunocompetent hosts. MR imaging is preferred for evaluating the extent of involvement and monitoring therapy response, given its high sensitivity and specificity, though imaging findings may be nonspecific. Herein, we review the imaging spectrum of Epstein-Barr virus-associated CNS disorders.

Electrically and Thermally Triggered Three-Dimensional Graphene-Foam-Reinforced Shape Memory Epoxy Composites

Shape memory polymer (SMP) epoxy composites have attracted significant attention due to their easy processing, lightweight nature, and ability to recover strain. However, their limited recovery rate and inferior mechanical properties have hindered their functional applications. This research explores the potential of three-dimensional (3D) graphene foam (GrF) as a highly efficient reinforcement for SMP epoxy composites. We demonstrated that the incorporation of a mere 0.13 wt.% GrF into mold-cast SMP epoxy leads to a 19% increase in the glass transition temperature (T_g). To elucidate the reinforcing mechanism, we fabricated and extensively analyzed composites with varying weight percentages of GrF. The GrF-based SMP epoxy composite exhibits a 57% increase in thermal conductivity, measuring 0.296 W mK^-1 at 70 °C, due to the interconnected 3D graphene network within the matrix. Notably, this composite also demonstrates remarkable electrical conductivity, making it suitable for dual-triggering applications. The GrF-SMP epoxy composite achieves a maximum shape recovery ratio and a significant 23% improvement in the recovery rate, effectively addressing the issue of slow recovery associated with SMPs. We investigated the effect of switching temperatures on the shape recovery rate. We identified the optimal triggering temperature to initiate shape recovery for epoxy SMP and GrF-epoxy SMP as thermal energy equivalent to T_g + 20 °C. Additionally, we fabricated a bird-shaped composite using GrF reinforcement, which showcases self-healing capabilities through the crack opening and closure and serves as a tangible demonstration of the transformative potential of the composite. These GrF-epoxy SMP composites, responsive to stimuli, hold immense promise for diverse applications, such as mechanical systems, wearable sensors, morphing wings, foldable robots, and antennas.

Understanding spatiotemporal mechanical behavior, viscoelasticity, and functions of stem cell-derived cardiomyocytes

Understanding myocytes' spatiotemporal mechanical behavior and viscoelasticity is a long-standing challenge as it plays a critical role in regulating structural and functional homeostasis. To probe the time-dependent viscoelastic behaviors of cardiomyocytes with cross-linked polymer networks, we measure stem cell-derived cardiomyocyte's (hiPSC-CM) deformation, adhesion, and contractility using atomic force microscopy (AFM) nanoindentation, fluidic micropipette, and digital image correlation (DIC). Our results show a cytoplasm load of 7-14 nN, a de-adhesion force of 0.1-1 nN, and an adhesion force between two hiPSC-CMs of 50-100 nN with an interface energy of 0.45 pJ. Based on the load-displacement curve, we model its dynamic viscoelasticity and discover its intimate associations with physiological properties. Cell detaching and contractile modeling demonstrate cell-cell adhesion and beating related strains manifesting viscoelastic behavior, highlighting viscoelasticity plays the primary role in governing hiPSC-CM spatiotemporal mechanics and functions. Overall, this study provides valuable information about the mechanical properties, adhesion behaviors, and viscoelasticity of single hiPSC-CM, shedding light on mechanical-structure relationships and their dynamic responses to mechanical stimuli and spontaneous contraction.

Advances in Acute Ischemic Stroke Treatment: Current Status and Future Directions

The management of acute ischemic stroke has undergone a paradigm shift in the past decade. This has been spearheaded by the emergence of endovascular thrombectomy, along with advances in medical therapy, imaging, and other facets of stroke care. Herein, we present an updated review of the various stroke trials that have impacted and continue to transform stroke management. It is critical for the radiologist to stay abreast of the ongoing developments to provide meaningful input and remain a useful part of the stroke team.

Bridging the Gap in Ashby's Map for Soft Material Properties for Tissue Engineering

Ashby's map's role in rationally selecting materials for optimal performance is well-established in traditional engineering applications. However, there is a major gap in Ashby's maps in selecting materials for tissue engineering, which are very soft with an elastic modulus of less than 100 kPa. To fill the gap, we create an elastic modulus database to effectively connect soft engineering materials with biological tissues such as the cardiac, kidney, liver, intestine, cartilage, and brain. This soft engineering material mechanical property database is created for widely applied agarose hydrogels based on big-data screening and experiments conducted using ultra-low-concentration (0.01-0.5 wt %) hydrogels. Based on that, an experimental and analysis protocol is established for evaluating the elastic modulus of ultra-soft engineering materials. Overall, we built a mechanical bridge connecting soft matter and tissue engineering by fine-tuning the agarose hydrogel concentration. Meanwhile, a soft matter scale (degree of softness) is established to enable the manufacturing of implantable bio-scaffolds for tissue engineering.

High throughput screening system for engineered cardiac tissues

Introduction: Three dimensional engineered cardiac tissues (3D ECTs) have become indispensable as in vitro models to assess drug cardiotoxicity, a leading cause of failure in pharmaceutical development. A current bottleneck is the relatively low throughput of assays that measure spontaneous contractile forces exerted by millimeter-scale ECTs typically recorded through precise optical measurement of deflection of the polymer scaffolds that support them. The required resolution and speed limit the field of view to at most a few ECTs at a time using conventional imaging. Methods: To balance the inherent tradeoff among imaging resolution, field of view and speed, an innovative mosaic imaging system was designed, built, and validated to sense contractile force of 3D ECTs seeded on a 96-well plate. Results: The system performance was validated through real-time, parallel contractile force monitoring for up to 3 weeks. Pilot drug testing was conducted using isoproterenol. Discussion: The described tool increases contractile force sensing throughput to 96 samples per measurement; significantly reduces cost, time and labor needed for preclinical cardiotoxicity assay using 3D ECT. More broadly, our mosaicking approach is a general way to scale up image-based screening in multi-well formats.

Membrane Remodeling of Human-Engineered Cardiac Tissue by Chronic Electric Stimulation

Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) show immature features, but these are improved by integration into 3D cardiac constructs. In addition, it has been demonstrated that physical manipulations such as electrical stimulation (ES) are highly effective in improving the maturation of human-engineered cardiac tissue (hECT) derived from hiPSC-CMs. Here, we continuously applied an ES in capacitive coupling configuration, which is below the pacing threshold, to millimeter-sized hECTs for 1-2 weeks. Meanwhile, the structural and functional developments of the hECTs were monitored and measured using an array of assays. Of particular note, a nanoscale imaging technique, scanning ion conductance microscopy (SICM), has been used to directly image membrane remodeling of CMs at different locations on the tissue surface. Periodic crest/valley patterns with a distance close to the sarcomere length appeared on the membrane of CMs near the edge of the tissue after ES, suggesting the enhanced transverse tubulation network. The SICM observation is also supported by the fluorescence images of the transverse tubulation network and α-actinin. Correspondingly, essential cardiac functions such as calcium handling and contraction force generation were improved. Our study provides evidence that chronic subthreshold ES can still improve the structural and functional developments of hECTs.

Localized Nanoindentation Paradigm for Revealing Sutured Tissue Interface Mechanics and Integrity

This study investigates the nanoindentation technique to elucidate the quasi-static and dynamic stress response at the wounded and sutured tissue interface. In vitro modeling and wound healing analysis enable an understanding of sutured tissue interface integrity, modulus, and stability using an artificial abdominal wall model. Sutured tissues with simple interrupted suturing (SIS) demonstrated a 35-40% higher modulus than simple continuous suturing (SCS). High-density suturing with a suture space of 2.5 mm exhibited a 2-fold higher modulus than low-density suturing with a suture space of 5 mm. The elastic modulus of the sutured pad immersed in deionized water was ∼70-95% of the dry condition. The dynamic stress data indicate that long-term body motions-triggered stress instability at the wound interface was affected by suturing style and density. The pivotal factors determining wound healing are quasi-static and dynamic modulus at the sutured interface, which is intimately associated with patient pain, wound complications, healing speed, and blood flow. The proposed method and data are an original approach to addressing wound healing, contributing to patient well-being and identifying, interpreting, and breaking the drawn-out debates in the suturing field.

Revealing nanomechanical deformation at the interface and degradation in all-thin-film inorganic electrochromic devices

Recently, progress in electrochromic (EC) devices has been made in optimizing electrode and device configurations and performance. However, the ion insertion/de-insertion induced charge transfer (CT) nanomechanical effect has remained unexplored, i.e., repetitive electrode size changes at the nanoscale and stress/strain generated during electrochemical cycling, which is the focus of this work due to its intimate correlation with the elastic and plastic deformation at the interface. Considering the intervalence electrons, excellent electrochemical kinetics, and dramatic color changes, tungsten oxide (WO₃) and nickel oxide (NiO) films are configured as the EC cathode and anode materials, respectively, within a full device. Upon extended cycles (>10 000), the void generation and delamination that occurred at the interface account for performance decay. Encouraged by the findings, nanoindentation mechanical tests and electrical kelvin probe force microscopy were employed to investigate the CT induced effects at the interface. There is a dramatic increase of up to 45% in the elastic Young's modulus in colored/charged WO₃ at ∼40 mC cm^-2. The correlation between CT and synergistic mechanical effect is interpreted by the Lippman equation. Interestingly, despite the charged state (colored; lithiated) with a relatively flat morphology bringing an ∼3.4 times higher electrostatic surface potential, the electrical work function unexpectedly decreases, arising from the dominant effect of the dipole layer potential over the chemical potential. The interatomic cohesive energy and equilibrium distance increase bury the seeds for mechanical deformation in the long run. This work provides fundamental insights into electro-chemo mechanics and interdisciplinary concerted interfacial effects at the nano/atomic level. The dependence of surface potential, stress, work function, and cohesive energy on electrochemical kinetics has been interpreted.

High-Resolution 7T MR Imaging of the Trochlear Nerve

BACKGROUND AND PURPOSE

The trochlear nerve has traditionally been difficult to identify on MR imaging. The advent of 7T MR imaging promises to greatly benefit visualization of small structures due to gains in the signal-to-noise ratio allowing improved spatial resolution. We investigated the utility of a clinically feasible ultra-high-resolution 7T MR imaging protocol for identification of the trochlear nerve, as well as assessment of normal trochlear nerve anatomy.

MATERIALS AND METHODS

Coronal high-resolution 2D T2-weighted TSE images used in a 7T epilepsy protocol of 50 subjects at our institution were reviewed by 2 independent radiologists for visualization of the trochlear nerve at the nerve origin and cisternal, tentorial, and cavernous segments. The frequency of nerve visibility within these segments and their anatomy were documented, and disagreements were resolved by joint review.

RESULTS

Of the 100 nerves reviewed in 50 subjects, at least 2 segments of the trochlear nerve from the brainstem to the cavernous sinus were identified in 100% of cases. The origins from the brainstem and cisternal segment were visible in 65% and 93% of nerves, respectively. The trochlear nerve was identified at the trochlear groove in 100% of cases and in the posterior wall of the cavernous sinus in 74% of cases.

CONCLUSIONS

Coronal high-resolution 2D TSE at 7T reliably identified the trochlear nerve throughout its course and is a promising tool for imaging patients with suspected trochlear nerve pathology.

Corrosion Behavior of 1D and 2D Polymorphs of Boron Nitride Ceramic

This study reports a fundamental electrochemical study to understand the corrosion behavior of 1D bulk, free-standing 1D boron nanotube (BNNT) buckypaper and compare it with a sintered 2D hBN nanoplatelet (BNNP) pellet. Tafel analysis indicates that 1D BNNT has superior corrosion resistance with a lower corrosion rate of 0.0026 mils per year (mpy). 2D BNNP, although having similar chemistry to 1D BNNT, resulted in an increased (40 times) corrosion rate of 0.107 mpy. The higher surface area and aspect ratio of BNNT drastically influenced the corrosion kinetics. The scientific outcomes will enable the better design of novel hBN-based corrosion-resistant materials.

Dynamic Control of Contractile Force in Engineered Heart Tissue

Three-dimensional engineered heart tissues (EHTs) derived from human induced pluripotent stem cells (iPSCs) have become an important resource for both drug toxicity screening and research on heart disease. A key metric of EHT phenotype is the contractile (twitch) force with which the tissue spontaneously beats. It is well-known that cardiac muscle contractility - its ability to do mechanical work - depends on tissue prestrain (preload) and external resistance (afterload).

OBJECTIVES

Here, we demonstrate a technique to control afterload while monitoring contractile force exerted by EHTs.

METHODS

We developed an apparatus that can regulate EHT boundary conditions using real-time feedback control. The system is comprised of a pair of piezoelectric actuators that can strain the scaffold and a microscope that can measure EHT force and length. Closed loop control allows dynamic regulation of effective EHT boundary stiffness.

RESULTS

When controlled to switch instantaneously from auxotonic to isometric boundary conditions, EHT twitch force immediately doubled. Changes in EHT twitch force as a function of effective boundary stiffness were characterized and compared to twitch force in auxotonic conditions.

CONCLUSION

EHT contractility can be regulated dynamically through feedback control of effective boundary stiffness.

SIGNIFICANCE

The capacity to alter the mechanical boundary conditions of an engineered tissue dynamically offers a new way to probe tissue mechanics. This could be used to mimic afterload changes that occur naturally in disease, or to improve mechanical techniques for EHT maturation.

Direct Observation of Adhesion and Mechanical Behavior of a Single Poly(lactic-co-glycolic acid) (PLGA) Fiber Using an In Situ Technique for Tissue Engineering

Nanometer- and submicrometer-sized fiber have been used as scaffolds for tissue engineering, because of their fundamental load-bearing properties in synergy with mechano-transduction. This study investigates a single biodegradable poly(lactic-co-glycolic acid) (PLGA) fiber's load-displacement behavior utilizing the nanoindentation technique coupled with a high-resolution in situ imaging system. It is demonstrated that a maximum force of ∼3 μN in the radial direction and displacement of at least 150% of fiber diameter should be applied to acquire the fiber's macroscopic mechanical properties for tissue engineering. The adhesion behavior of a single fiber is captured using a high-resolution camera. The digital image correlation (DIC) technique is adopted to quantify the adhesion force (∼25 μN) between the fiber and the tip. Adhesion force has also been quantified for the fiber after immersing in phosphate-buffered saline (PBS) to mimic the bioenvironment. A 4-fold increase in adhesion force after PBS treatment was observed due to water penetration and hydrolysis on the fiber's surface. A high similarity between mechanical properties of a single fiber and native tissues (elastic modulus of 10-25 kPa) and superior adhesion force (25-107.25 μN) was observed, which is excellent for promoting cell-matrix communication. Overall, this study examines the mechanics of a single fiber using innovative indentation and imaging processing techniques, disclosing its profound and striking roles in tissue engineering.

Feasibility and impact of a one-stop thyroid clinic in a low- and middle-income country

BACKGROUND

The study was done to evaluate the feasibility, safety and outcomes of a one-stop thyroid clinic (OSTC) in a low- and middle-income country (LMIC) setting.

METHODS

This was a prospective non-randomised case control study consisting of patients with thyroid nodules evaluated and managed at a tertiary referral centre in an LMIC between February 2019 and January 2020. Patients were divided into two groups based on the kind of preoperative evaluation protocol: OSTC group (n = 118) - OSTC protocol, and control group (CG, n = 108) - routine protocol.

RESULTS

Baseline clinical characteristics of the two groups including median age (p = 0.13) and gender distribution (p = 0.76) were comparable. The majority of patients in both groups belonged to a low-income group (46.6% vs 47.3%; p = 0.91), followed by a middle-income group (35.6% vs 30.5%; p = 0.41). The median number of outpatient department visits (1 vs 3 days; p = < 0.001), waiting time for neck ultrasonography (1 vs 3 days; p = < 0.0001), fine needle aspiration cytology (1 vs 2 days; p = < 0.0001), and out of pocket expenditure (INR 3 965 vs 6 624; p = < 0.001) was significantly less in the OSTC group compared to the CG. Patients in the OSTC group reported better satisfaction levels (p = < 0.0001). Accuracy of diagnosis did not differ between the two groups (p = 0.14).

CONCLUSION

OSTC practice is feasible, provides comparative clinical outcomes and seems cost effective in an LMIC. This protocol can be adopted as a routine practice in any health system.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

P-291 Positive effects of inactivated blood serum in stabilizing the activity of antioxidants in embryo-free culture media

Study question

Does addition of blood serum to embryo culture media supplemented with antioxidants (AOXs) helps maintain the AOX activity under in vitro culture conditions?

Summary answer

The addition of inactivated blood serum (IBS) before AOX supplementation resulted in AOX activity stabilization in embryo-free culture media (EFCM) for up to 48 hours.

What is known already

Supra-physiological levels of reactive oxygen species (ROS) in embryo culture medium (ECM) can disturb embryo development possible due to oxidative stress. Hence, AOX supplementation of ECM has been used to counteract the potential negative effects of high ROS on gametes and embryos. However, rapid consumption of AOXs via interaction with ROS may reduce the AOX protection capacity particularly during extended culture conditions. The aim of this study is to investigate the efficacy of IBS in stabilizing the AOX activity of a combination of AOXs (EmbryORP®) when added to EFCM.

Study design, size, duration

In this prospective study, oxidation reduction potential (ORP) was assessed in EFCM by MiOXSYS System (UAB Caerus Biotechnologies, Vilnius, Lithuania). The ORP results reflect the overall balance between oxidants and antioxidants. ORP levels in follicular fluid obtained from dominant follicles of 40 oocyte donors were used as control.

Participants/materials, setting, methods

All dishes containing culture medium (GlobalTotal®, LifeGlobal®, Connecticut, US) were incubated for 48 hours in 8% CO2, 20% O2, 37 °C. Culture dishes were divided into four groups: Group A: EFCM without AOX, Group B: EFCM+AOX, Group C: EFCM+AOX+IBS, and Group D: EFCM+IBS. Levels of ORP were assessed in EFCM before AOX supplementation (0), immediately after adding AOX (1) and 48 hours following AOX supplementation (2). ORP results are expressed as millivolts (mV).

Main results and the role of chance

At 48 hours of culture, ORP value in group C (96.7 mV) was significantly lower than group A (345 mV; p = 0.00001), and was found to be similar to the physiological ORP values found in follicular fluid from donors (89 mV±23.6 mV; p &gt; 0.05). Also, ORP value in group C (96.7 mV) was lower than group B (210 mV; p = 0.67) and group D (280.1 mV; p = 0.11).

Limitations, reasons for caution

This study only tested the efficacy of IBS as AOX stabilizer in EFCM over 48 hours. The efficacy and potential risks associated with the use of IBS during actual embryo culture were not examined.

Wider implications of the findings

The use of AOX stabilizers may represent an important novel finding to maintain sufficient AOX protective capacity during extended culture conditions.

Trial registration number

10112021-AOX

P-148 Denudation employing human recombinant hyaluronidase enzyme does not affect fertilization and blastocyst formation rates in sibling oocytes from patients undergoing ART: A prospective randomized study

Study question

Does human recombinant hyaluronidase (Cumulase®) improve fertilization and blastocyst formation rates in sibling human oocytes compared to bovine-derived hyaluronidase?

Summary answer

The use of Cumulase® for oocyte denudation does not appear to affect fertilization or usable blastocyst formation rate in patients undergoing intracytoplasmic sperm injection (ICSI).

What is known already

Bovine-derived hyaluronidase has been widely employed to denude the cumulus-oocyte complexes (COCs) prior to ICSI or oocyte vitrification. Nonetheless, the recent concern for its safety, due to its animal origin, has led to the development of alternatives ascertaining the enzyme’s purity. It has been reported that human recombinant hyaluronidase is not equally effective as its bovine-derived analogue, leading to a longer time required for complete denudation coupled by the subsequent toxicity risk for oocytes. This may result to lower fertilization and blastocyst formation rates. Although there are some studies on IVF outcomes with recombinant hyaluronidase, its use remains rather limited.

Study design, size, duration

This randomized double-blinded clinical trial was conducted at Citmer Reproductive Medicine, in Puebla and Monterrey, Mexico from February to December 2021. The impact of denudation on sibling oocytes from 103 patients employing bovine-derived hyaluronidase (InVitroCare®) or human recombinant hyaluronidase (ICSI Cumulase® (rHuPH20), CooperSurgical®) was evaluated. A total of 1237 oocytes were assigned as follows: The Hyaluronidase Group included 626 oocytes, while the Cumulase® Group included 611 oocytes. Preimplantation Genetic Testing was performed in 18 cycles.

Participants/materials, setting, methods

After retrieval, COCs were incubated for 2-4 h and placed in microdropets with 10 IU/mL bovine-derived hyaluronidase or Cumulase® in culture media GlobalTotal® (LifeGlobal®) for granulosa cells removal. COCs were gently pipetted up and down employing 20 μL and 150 μm tips. Metaphase II oocytes were injected and incubated for 17-20 hours in 8% CO2, 20% O2, 37°C. Normally fertilized zygotes were cultured to blastocyst stage and embryo development was evaluated. Seventy-nine blastocysts were biopsied.

Main results and the role of chance

The mean age of the patients was 32.12±1.11 years old. A total of 506 and 493 metaphase II oocytes from Groups 1 and 2 respectively were subjected to ICSI. Normal fertilization rates for oocytes treated with Hyaluronidase and Cumulase® were 71.34% (n = 361) and 72.41% (n = 357) respectively, with no statistically significant differences between the two groups (p = 0.35).

Usable blastocysts rate (selected for embryo transfer or blastocyst cryopreservation) did not differ with any statistical difference between the bovine-derived hyaluronidase (n = 170, 47.09%) and the Cumulase® treated oocytes (n = 158, 44.25%), (p = 0.44).

Preimplantation genetic testing for aneuploidies (PGT-A) was performed in 18 cycles. Seventy-nine blastocysts were biopsied and tested. Fourty-seven embryos from the bovine-derived hyaluronidase group were biopsied, presenting with a euploidy rate of 51.06% (n = 24), compared to 32 embryos from the recombinant hyaluronidase group with a euploidy rate of 50% (n = 16). Results indicated no statistically significant difference (p = 0.92). These data support that human recombinant hyaluronidase presents with similar efficacy to bovine-derived hyaluronidase. in terms of normal fertilization, embryo development as well as euploidy rates.

Limitations, reasons for caution

The small sample size regarding the euploidy outcome stands as a limitation of the study. Further studies should focus on the effect of recombinant hyaluronidase on genetic anomalies on blastocysts.

Wider implications of the findings

Fertilization, usable blastocyst and euploidy rates did not differ when employing bovine-derived or human recombinant hyaluronidase, rendering the latter a safe and efficient alternative. However, it is important to assess long-term effects, as only a limited number of studies report on perinatal and neonatal outcomes

Trial registration number

25-12-21MTYPUECIT

P-086 AZF Microdeletions: A New Look at Past Paradigms

Study question

To elucidate whether AZF screening is indicated in men with proven non-obstructive azoospermia (NOA) or severe oligozoospermia (&lt;5x106 sperm/mL) who concomitantly harbor chromosomal abnormalities.

Summary answer

Some chromosomal aberrations are concomitant with AZF microdeletions, and hence Y chromosome microdeletion (YCM) screening is necessary for these patients.

What is known already

In the era of assisted reproduction, finding cost-minimization strategies in infertility clinics without affecting the quality of diagnosis and treatment is becoming one of the top-priority topics for future research. Formulating definitive guidelines concerning the indications for paraclinical testing could be one of the strategies. Accordingly, definitive guidelines for AZF screening do not exist especially in men who also have chromosomal abnormalities. The current clinical practice is to decide per case whether to pursue further molecular testing, with the accompanying added psychological and socio-economic burden.

Study design, size, duration

An observational retrospective cohort study of 10,388 consecutive cases from a tertiary infertility referral center (Royan institute, Tehran, Iran) over the last 12 years. A comprehensive literature review was also performed to summarize scientific evidence.

Participants/materials, setting, methods

The study recruited the largest cohort of men with primary infertility (NOA or severe oligozoospermia) ever presented who underwent screening for cytogenetic abnormalities and YCMs using sequence-tagged sites-polymerase chain reaction (STS-PCR) with a primer set covering the AZF regions according to the EAA/EMQN guidelines, as part of the infertility workup prior to ART.

Main results and the role of chance

In total, one-third of men with YCMs concomitantly had an abnormal karyotype (excluding those with heteromorphisms) (169/565; 29.9%, 95% CI: 26.3-33.8). In respect to the frequency of YCMs, our findings suggest that the cases diagnosed with 46,X,add(X) with incidence of 1.8% (3/169; 95% CI: 0.6-5.1); 45,X and mosaic forms: 45,X/46,X,inv(Y)(p11.2q12); 45,X/46,X,del(Y); 45,X,der(Y;Autosome); 45,X/46,X,idic(Y)(p11.2); 45,X/46,XY,r(Y); and 45,X/46,X,idic(Y)(q11.2) (19/169; 11.2%, 95% CI: 7.3-16.9); and inv(Y)(p11.2q12) (2/169; 1.2%, 95% CI: 0.3-4.2) should also be referred for AZF deletion screening, as data suggests they are accompanied with YCMs.

Limitations, reasons for caution

The extension of the outcomes beyond the described population could introduce concerns on appropriate medical management. Confirmatory studies in other geographic/ethnic groups are still necessary to reach a consensus regarding the outcomes.

Wider implications of the findings

It has been recommended that all men with NOA who have chromosomal abnormalities, except those with 46,XY/45,X karyotype, do not need AZF testing. The results reflect a crucial need for reconsidering whether YCM testing is indicated in the population of men with certain karyotypic abnormalities.

Trial registration number

Not Applicable

P-012 Investigating the potential role of microRNAs as biomarkers in idiopathic non-obstructive azoospermia: A systematic review and in-silico analysis of the affected pathways

Study question

Is there an association between microRNA profiles in seminal plasma and microRNAs profiles in testicular tissue samples obtained from idiopathic non-obstructive azoospermia (NOA) patients?

Summary answer

This study identified common alterations in microRNA profiles and gene expression patterns between seminal plasma and testicular tissue samples obtained from NOA patients.

What is known already

Despite the significant advances in the field of reproductive medicine the exact infertility aetiology remains unidentified regarding 30-40% of infertile men. This fact highlights the need for more accurate and sensitive diagnostic tools and biomarkers, especially regarding the most severe cases of male infertility, such as idiopathic NOA patients. It has been voiced that microRNA profiling of seminal plasma and testicular tissue samples obtained from idiopathic NOA patients could be a powerful tool towards better understanding the underlined pathogenesis and towards developing novel diagnostic and individualized biomarkers. However, a collective analysis of these data has not been performed hitherto.

Study design, size, duration

A systematic review was performed in PubMed/Medline and Embase up to November 2020. Search strategy included a combination of keywords, namely non-coding RNA OR small non-coding RNA OR microRNA AND non-obstructive azoospermia. Following study selection, original data on altered microRNAs were analyzed aiming to underline differences between microRNA expression profiles in seminal plasma and testicular tissue samples of idiopathic NOA cases. Following this, in-silico analysis was performed to detect commonly affected gene expression pathways.

Participants/materials, setting, methods

Only full-length original retrospective or prospective human studies were included. Strict inclusion-exclusion criteria were applied. The studied population consisted of idiopathic NOA patients, while the control groups consisted of men with normal semen analysis. In-silico analysis was performed employing a combination of bioinformatic tools, namely the DIANA-TarBase, microT-CDS, the GTEx repository and the KEGG database. Statistical analysis was performed using the R-package-limma. The statistically significant threshold indicating altered gene pathways was set at 0.01 P-value.

Main results and the role of chance

Five studies were considered eligible, including 382 NOA cases and 412 controls (Finocchi et al., 2020; Song et al., 2017; Wu et al., 2013; Wu et al., 2012; Wang et al., 2011). Two studies co-evaluated the profile of microRNAs in both seminal plasma and testicular tissue samples (Wu et al., 2013; Wu et al., 2012), one study evaluated only testicular tissue (Song et al., 2017) and the other two only seminal plasma (Finocchi et al., 2020 and Wang et al., 2011). Data extraction revealed a total of 14 differentially expressed microRNAs between NOA patients and controls. The following microRNAs were found to be up-regulated in both seminal plasma and testicular tissue samples of NOA cases: hsa-miR-141-3p, hsa-miR-429, hsa-miR-7-1-3p, hsa-miR-19b-3p and hsa-let-7a-5p. The hsa-miR-188-3p was found to be down-regulated in testicular tissue samples. Finally, the following microRNAs were also downregulated only in seminal plasma: hsa-miR-34c-5p, hsa-miR-122-5p, hsa-miR-181a-5p, hsa-miR-146b-5p, hsa-miR-374b-5p, hsa-miR-509-5p, hsa-miR-513a-5p and hsa-miR-34b-3p. Despite the limited number of common microRNAs between seminal plasma and testicular tissue samples, in-silico analysis revealed 34 statistically significant dysregulated gene pathways, regarding both seminal plasma and testicular tissue samples, indicating that idiopathic NOA patients are sharing several common altered molecular mechanisms involved in NOA pathogenesis.

Limitations, reasons for caution

The limited number of the included studies as well as the small size population characterizing the great majority of them, constitute the main limitations of this systematic review. Moreover, great heterogeneity was observed among the studies regarding the molecular methods employed for microRNA profiling.

Wider implications of the findings

These collective findings indicate that microRNA profiling in seminal plasma could indeed be raised as a powerful non-invasive tool towards better understanding and diagnosing idiopathic NOA. Larger well-controlled studies employing state-of-the-art microRNAome techniques are needed to validate these conclusions. Moreover, the molecular network of targeted gene pathways also merits investigation.

Trial registration number

Not Applicable

P-226 Efficiency of different antioxidants in reducing the supra-physiological Oxidation Reduction Potential Levels in human embryo culture media

Study question

Does every antioxidant compounds perform similarly in reducing the excessive levels of Oxidation Reduction Potential (ORP) in IVF culture media?

Summary answer

Not all antioxidant compounds perform similarly in maintaining physiological ORP levels in IVF culture media.

What is known already

During assisted reproduction technologies (ART), several external factors are responsible for disturbing the ORP equilibrium in gametes and embryos. Therefore, antioxidant supplementation of culture media has been evaluated and reported. However, there is lack of consensus on the efficiency of antioxidant action in embryo culture media. Antioxidants are known to lower the levels of free radical concentration to physiological levels, preventing cellular damage caused by oxidative stress. Therefore, it is important to determine which antioxidant compound are the most effective in reducing ORP levels in embryo culture media.

Study design, size, duration

In this prospective study was performed at CITMER Reproductive Medicine, Mexico city. ORP levels were measured by MiOXSYS System (UAB Caerus Biotechnologies, Vilnius, Lithuania) in embryo-free culture medium (Global® Total®, LifeGlobal®, Connecticut, US). Embryo-free culture medium was supplemented with cumene hydroperoxide and seven different antioxidants were tested each day for 5 continuous days (n = 40). Follicular fluid ORP levels from dominant follicles of 40 oocyte donors were used as control and considered as a physiological target.

Participants/materials, setting, methods

Cumene hydroperoxide (CH) 1mM, was utilized to increase ORP values in culture media from 224 mV to 415 mV. The following compounds considered as antioxidants according to literature were supplemented at 2 mM to the CH culture media: Ascorbic acid (ASC), L-Carnitine (CAR), L-Cysteine (CYS), Glutathione (GLT), Curcumin (CU), Resveratrol (RSV) and b-Mercaptoethanol (BME). ORP levels were quickly evaluated each time.

Main results and the role of chance

In this study, CH was used as a culture media oxidant to measure the antioxidants capacity in lowering the excessive ORP values of CH culture media. ORP in CH solution was 415 mV ± 4.3. All antioxidants showed a statistically different capacity (p &lt; 0.05) to lower the ORP values when added to CH solution: RSV decreased the ORP to 348.3 mV ± 3.6 p = 0.0449, CAR to 316.32 mV ± 4.7 (p &lt; 0.0001), CU to 315.7 mV ± 4.4 (p &lt; 0.0001) and GLT to 258.4 mV ± 15.1 (p = 0.00002). The compounds that showed higher antioxidant capacity were CYS 158.4 mV ± 4.7 (p &lt; 0.00001), ASC 154.1 mV ± 3.1 (p &lt; 0.00001) and BME 136.1 mV ± 9.6 (p &lt; 0.00001). CYS, ASC and BME ORP values reached the physiological ORP values found in follicular fluid from donors, which are 89 mV±23.6 mV.

Limitations, reasons for caution

Further studies should focus on the comparison between physiological dynamics of antioxidant supplementation on culture media and molecular and biochemical effect of antioxidants on embryos and gametes.

Wider implications of the findings

According to our results, CYS, ASC and BME were significantly more potent antioxidants in lowering the ORP in culture medium to physiological levels. The measurement of antioxidant capacity in lowering excess of ROS in culture media may assist in developing the most effective antioxidant supplements, thus improving ART outcomes.

Trial registration number

none

The extrapyramidal syndromes of chronic kidney disease and dialysis (EPS-CKDD): diagnostic criteria, risk factors and prognosis

BACKGROUND

Acute extrapyramidal movement disorders in dialysis patients are rare, inconsistently defined and have uncertain aetiology and prognosis.

AIM

Define diagnostic criteria, prognosis and risk factors.

DESIGN AND METHODS

Retrospective case series review of 20 patients (14 female, mean age 62 years) receiving dialysis for a median of 15 (interquartile range 4-35) months who presented with acute parkinsonism (AP = 11) or chorea/athetosis (CA = 9).

RESULTS

All patients had type 2 diabetes (HbA1c 6.8 ± 1.0) and had received metformin. Lactic acidosis was present in 2 patients at presentation and serum lactate was elevated in 7/15 patients tested. No patient had abnormal copper or thyroid metabolism and 5/8 patients tested returned marginal abnormalities in heavy metal screening. Magnetic resonance imaging (MRI) revealed characteristic bilateral symmetric T2 hyperintensity of the basal ganglia (BG), predominantly putamen and globus pallidus (the lentiform nucleus) and more extensive involvement of the external and internal capsules in patients with AP presentation. Post-mortem demonstrated cytotoxic necrosis of the BG. Therapy included thiamine, intensive dialysis and cessation of metformin. Two patients died acutely, nine recovered and nine had residual symptoms. Median survival did not differ by presentation: AP 24 [95% confidence interval (CI) 21-27] and CA 33 (95% CI 32-35) months, P = 0.21.

CONCLUSIONS

There are two distinct clinical extrapyramidal movement disorders associated with specific diagnostic MRI imaging that support the diagnosis of the extrapyramidal syndromes of chronic kidney disease and dialysis. The associations with diabetes, metformin and metabolic acidosis suggest a common pathogenic mechanism but require additional study. Early recognition and treatment may improve outcomes.

Engineering a living cardiac pump on a chip using high-precision fabrication

Biomimetic on-chip tissue models serve as a powerful tool for studying human physiology and developing therapeutics; however, their modeling power is hindered by our inability to develop highly ordered functional structures in small length scales. Here, we demonstrate how high-precision fabrication can enable scaled-down modeling of organ-level cardiac mechanical function. We use two-photon direct laser writing (TPDLW) to fabricate a nanoscale-resolution metamaterial scaffold with fine-tuned mechanical properties to support the formation and cyclic contraction of a miniaturized, induced pluripotent stem cell-derived ventricular chamber. Furthermore, we fabricate microfluidic valves with extreme sensitivity to rectify the flow generated by the ventricular chamber. The integrated microfluidic system recapitulates the ventricular fluidic function and exhibits a complete pressure-volume loop with isovolumetric phases. Together, our results demonstrate a previously unexplored application of high-precision fabrication that can be generalized to expand the accessible spectrum of organ-on-a-chip models toward structurally and biomechanically sophisticated tissue systems.

Phosphonomethyl iminodiacetic acid functionalized metal organic framework supported PAN composite beads for selective removal of La(III) from wastewater: Adsorptive performance and column separation studies

The rare earth elements being toxic in nature are being accumulated in water bodies as their industrial usage is growing exponentially, thus their efficient separation holds an immense significance. Herein, ligand functionalized metal organic framework (MOF), Phosphonomethyl iminodiacetic acid coordinated at Fe-BTC, was synthesized post-synthetically and incorporated subsequently in polyacrylonitrile polymer to prepare the composite beads via nonsolvent induced-phase-inversion technique for selective adsorption of La(III) from the wastewater in batch and dynamic column mode. XPS NMR, and FTIR were used to establish the interaction between functionalized ligand and unsaturated metal nodes of MOF. The adsorption capacity was 232.5 mg/g and 77.51 mg/g at 298 K of the functionalized MOF and composite beads respectively. Adsorption kinetics followed a pseudo-second order rate equation, and isotherm indicated the best fitting with Langmuir model. The dynamic behavior of the adsorption column packed with MOF/Polymer beads was fairly described by the Thomas model. The breakthrough time of 23.2 h could be attained with 12 cm of bed height and 10 ml/min of flow rate. These MOF/Polymer beads shown the selectivity of La over transitional metals were recycled over 5 times with about 15% loss of adsorption capacity. The findings provide suggestive insights of the potential use of functionalized MOF towards the separation of the rare earth element.

Predictive performance of the Garvan Fracture Risk Calculator: a registry-based cohort study

The G arvan Fracture Risk Calculator predicts risk of osteoporotic fractures. We evaluated its predictive performance in 16,682 women and 2839 men from Manitoba, Canada, and found significant risk stratification, with a strong gradient across scores. The tool outperformed clinical risk factors and bone mineral density for fracture risk stratification.

INTRODUCTION

The optimal model for fracture risk estimation to guide treatment decision-making remains controversial. Our objective was to evaluate the predictive performance of the Garvan Fracture Risk Calculator (FRC) in a large clinical registry from Manitoba, Canada.

METHODS

Using the population-based Manitoba Bone Mineral Density (BMD) registry, we identified women and men aged 50-95 years undergoing baseline BMD assessment from September 1, 2012, onwards. Five-year Garvan FRC predictions were generated from clinical risk factors (CRFs) with and without femoral neck BMD. We identified incident non-traumatic osteoporotic fractures (OFs) and hip fractures (HFs) from population-based healthcare data sources to March 31, 2018. Fracture risk was assessed from area under the receiver operating characteristic curve (AUROC). Cox regression analysis and calibration ratios (5-year observed/predicted) were assessed for risk quintiles. All analyses were sex stratified.

RESULTS

We included 16,682 women (mean age 66.6 + / - SD 8.7 years) and 2839 men (mean age 68.7 + / - SD 10.2 years). During a mean observation time of 2.6 years, incident OFs were identified in 681 women and 140 men and HFs in 199 women and 22 men. AUROC showed significant fracture risk stratification with the Garvan FRC. Tool predictions without BMD were better than from age or decreasing weight, and the tool with BMD performed better than BMD alone. Garvan FRC with BMD performed better than without BMD, especially for HF prediction (AUROC 0.86 in women, 0.82 in men). There was a strong gradient of increasing risk across Garvan FRC quintiles (highest versus lowest, hazard ratios women 5.75 and men 3.43 for any OF; women 101.6 for HF). Calibration differences were noted, with both over- and underestimation in risk.

CONCLUSIONS

Garvan FRC outperformed CRFs and BMD alone for fracture risk stratification, particularly for HF, but may require recalibration for accurate predictions in this population.

Anatomage - the virtual dissection tool and its uses: A narrative review

Advancement in technology has given students and institutes an educational, interactive, and diagnostic aid with virtual reality functionality known as the Anatomage table. This review analyses the various spheres of the medical field where the 3D virtual tool is being used and assesses its acceptability, convenience, and practical application. A search for relevant studies in various databases namely Pubmed, Embase, Wiley Library, and Google Scholar was performed, and the data was compiled to understand the use of the Anatomage table. The search yielded a total of 24 studies that focused on the use of the Anatomage table. Eleven articles focused on using Anatomage as a learning tool and 13 described the perception of the Table. Anatomage table offers an excellent tool for learning anatomy by virtual dissection. The tool is not only used as a teaching aid, but also as a diagnostic and planning tool in residency programs. Adding the tool as an educational aid boosts the existing curriculum and helps to counter the challenges with cadaveric dissection. The equipment cost and its maintenance charges may be a deciding factor for the underutilization of the tool in developing countries.

Outcomes among preterm infants with patent ductus arteriosus: Relationship with treatment, gestational age, hemodynamic status and timing of treatment

BACKGROUND

There remains controversy regarding the outcomes resulting from treatment versus conservative management of patent ductus arteriosus (PDA) among preterm infants. The effects of extreme prematurity, hemodynamic status of the PDA, and age at treatment remain poorly defined.

STUDY DESIGN

This retrospective case-control study including infants <  1250 gm who were categorized into 3 groups: Group 1: without PDA, Group 2: with untreated PDA, and Group 3: treated PDA. Diagnosis and treatment of PDA extracted from the medical records. Demographics, clinical characteristics, and outcomes compared using chi-square and analysis of variance. Logistic regression used to estimate adjusted odds ratios.

RESULTS

The study included 734 infants, with 141(19%) in Group 1, 329 (45%) in 2, and 264 (36%) in 3. Group 3 had higher incidence of bronchopulmonary dysplasia (BPD) (aOR, 2.9; 95%CI 1.7-4.8). Infant treated for hemodynamically significant PDA (HSPDA) had higher incidence of BPD (aOR, 1.9; 95%CI 1.0-3.8) and retinopathy of prematurity (ROP) (aOR, 3.4; 95%CI 1.6-6.9). There were no differences in outcome associated with treatment among≤26 weeks gestation and the age when treated.

CONCLUSION

Infants with PDA who were treated had higher incidence of BPD. Among those who were treated, those with HSPDA had a higher incidence of BPD and ROP.

785 Is Subspecialisation Important for The Emergency Laparotomy Outcomes?

Introduction

High mortality and morbidity is associated with Emergency Laparotomy. This study looks at outcomes of different subspecialties of surgeons performing Emergency Laparotomies identified from National Emergency Laparotomy Audit (NELA).

Method

Results

Conclusions

482 Is Subspecialisation Important for Emergency Laparotomy Outcomes?

Introduction

High mortality and morbidity is associated with Emergency Laparotomy. This study looks at outcomes of different subspecialties of surgeons performing Emergency Laparotomies identified from National Emergency Laparotomy Audit (NELA).

Method

Results

Conclusions