Comparison of physicochemical parameters, microbial community composition and flavor substances during mechanical and traditional brewing process of Jiang-flavor baijiu

Mechanized, automated and intelligent brewing is an important trend of innovation and transition in Jiang-flavor baijiu industry. In this study, physicochemical parameters, microbial community composition and flavor substances during 3rd round heap fermentation between mechanical and traditional workshop were investigated and compared based on traditional culturable methods, high-throughput sequencing technology and gas chromatography analysis. The dominant bacterial and fungal genera were consistent between the two workshops, but mechanized brewing had a significant impact on the composition of fungal communities. Rhodococcus and Monascus were special genera in mechanical workshop. The interaction relationship between physicochemical parameters and dominant microorganisms in mechanized workshop was different from traditional workshop as well. This study provided a scientific basis for further analyzing the mechanism of mechanized brewing of Jiang-flavor baijiu.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01483-y.

Efficacy of Continuous Lateral Rotation Therapy in Mechanically Ventilated Critically Ill Adults on Clinical Outcomes

Background: This PICO-guided systematic review assessed continuous lateral rotation therapy (CLRT) versus conventional position changes in mechanically ventilated critically ill adults, evaluating mortality, intensive care unit (ICU) and hospital stay duration as primary outcomes, and respiratory function, mechanical ventilation duration, pulmonary complications, and adverse events, as secondary outcomes. Methods: A systematic review followed PRISMA criteria (PROSPERO CRD42022384258). Searches spanned databases: MEDLINE/PubMed, EMBASE, Scopus, ScienceDirect, Cochrane, CINAHL and Web of Science, without language or publication year restrictions. Inclusion criteria involved randomized (RCT) and quasi-randomized trials, comparing CLRT (intervention) with conventional position changes (control). Risk of bias and quality of evidence for RCTs were assessed using the Cochrane collaboration and GRADE tools. For the quasi-randomized trials, the ROBINS-I tool was used. Results: In 18 studies with 1.466 participants (intervention, n= 700, 47.7%; control, n= 766, 52.2%), CLRT was predominantly used for prophylactic purposes, with protocols varying from 10 to 24 hours/day. Meta-analysis (16 RCTs) favored CLRT for reduced mechanical ventilation duration (SMD -0.17 days, CI -0.29 to -0.04, p=0.008) and lower nosocomial pneumonia incidence (OR 0.39, CI 0.29 to 0.52, p<0.00001). CLRT showed no significant impact on mortality (OR 1.04, CI 0.80 to 1.34, p= 0.77), ICU stay (SMD -0.11 days, CI -0.25 to 0.02, p= 0.11), hospital stay (SMD -0.10 days, CI -0.31 to 0.11, p= 0.33) and incidence of pressure ulcers (OR 0.73, CI 0,34 to 1.60, p= 0.44). Conclusions: CLRT showed no significant difference in primary outcomes (mortality, ICU, and hospital stay duration) but revealed significant differences in secondary outcomes (consistently reduced nosocomial pneumonia, with a minor effect on MV duration), supported by moderate certainty. Very low certainty for other outcomes highlights the need for current studies in diverse clinical settings and protocols to assess CLRT effectiveness.

Electrodeposited carbon nanostructured nickel composite coatings: A review

The utilization of high-strength materials that can retain their strength after successive use under high mineral moisture (maximum weight of 1098 kg) for aerospace, automotive, and electromagnetic devices is challenging. Generally, coatings of nickel (Ni) and its alloys are utilized in the aforementioned applications, but the continuous use of the system degrades its mechanical stability and structural integrity. For the automotive and aerospace uses, the material should have high mechanical strength, wear tolerance, corrosion resistance, and magnetism. The bare Ni coatings can be altered with enhanced mechanical, tribological and electrochemical performances by using various reinforcements in the coatings. The abundantly used reinforcing agents are mainly carbonaceous nanoallotropes (such as graphene, carbon nanotubes, and diamond) for the fabrication of composite coatings. The current review unfolds the introduction of nickel and the major cause of damage to bare nickel coatings. Moreover, the review sheds light on how to mitigate the damage of nickel coatings with an emphasis on giving a flavor of distinct carbonaceous nanoallotropes. The conjugated studies on mechanical, wear, corrosion, and magnetic behavior of electrodeposited Ni-carbonaceous composite coatings are embraced in the review. Therefore, the present review can be endorsed by the readers for the protection of aircraft, automotive, and electromagnetic appliances.

Comparison of automated and manual control methods in minimal flow anesthesia

PURPOSE

New-generation anesthesia machines administer inhalation anesthetics and automatically control the fresh gas flow (FGF) rate. This study compared the administration of minimal flow anesthesia (MFA) using the automatically controlled anesthesia (ACA) module of the Mindray A9 (Shenzhen, China) anesthesia machine versus manual control by an anesthesiologist.

METHODS

We randomly divided 76 patients undergoing gynecological surgery into an ACA group (Group ACA) and a manually controlled anesthesia group (Group MCA). In Group MCA, induction was performed with a mixture of 40-60% O2 and air with a 4 L/min FGF until the minimum alveolar concentration (MAC) reached 1. Next, MFA was initiated with 0.5 L/min FGF. The target fraction of inspired oxygen (FiO2) value was 35-40%. In Group ACA, the MAC was defined as 1, and the FiO2 was adjusted to 35%. Depth of anesthesia, anesthetic agent (AA) consumption, time to achieve target end-tidal AA concentration, awakening times, and number of ventilator adjustments were analyzed.

RESULTS

The two groups showed no statistically significant differences in depth of anesthesia or AA consumption (Group ACA: 19.1 ± 4.9 ml; Group MCA: 17.2 ± 4.5; p-value = 0.076). The ACA mode achieved the MAC target of 1 significantly faster (Group ACA: 218 ± 51 s; Group MCA: 314 ± 169 s). The number of vaporizer adjustments was 15 in the ACA group and 217 in the MCA group.

CONCLUSION

The ACA mode was more advantageous than the MCA mode, reaching target AA concentrations faster and requiring fewer adjustments to achieve a constant depth of anesthesia.

Inhalation Injury, Respiratory Failure, and Ventilator Support in Acute Burn Care

Sustaining an inhalation injury increases the risk of severe complications and mortality. Current evidential support to guide treatment of the injury or subsequent complications is lacking, as studies either exclude inhalation injury or design limit inferences that can be made. Conventional ventilator modes are most commonly used, but there is no consensus on optimal strategies. Settings should be customized to patient tolerance and response. Data for pharmacotherapy adjunctive treatments are limited.

Dentin remineralization using a stimuli-responsive engineered small molecule GSK3 antagonists-functionalized adhesive

OBJECTIVES

Tideglusib has shown great performance in terms of dentin regenerative properties. This study aims to evaluate bonding ability, of demineralized dentin infiltrated with polymeric nanoparticles (NPs) doped with tideglusib (TG) (TG-NPs).

METHODS

Dentin conditioned surfaces were infiltrated with NPs and TG-NPs. Bonded interfaces were created and stored for 24 h and then submitted to mechanical, chemical and thermal challenging. The resin-dentin interface was evaluated through a doubled dye fluorescent technique and a calcium chelator fluorophore under a confocal laser scanning microscopy, and by field emission scanning electron microscopy.

RESULTS

Dentin surfaces treated with TG-NPs and load cycled produced higher bond strength than the rest of the groups. Immersion of dentin specimens treated with undoped-NPs in collagenase solution attained the lowest microtensile bond strength (MTBS) values. Both porosity and nanoleakage decreased when dentin was infiltrated with TG-NPs, that revealed strong signals of xylenol orange stain at both hybrid layer and dentinal tubules. The presence of NPs, in general, inducted the presence of mineralized interfaces after mechanical loading and thermocycling.

CONCLUSIONS

Nanoparticles doped with tideglusib promoted the highest dentin bonding efficacy among groups, as they facilitated the maximum bond strength values with creation of mineral deposits at the hybrid layer and dentinal walls. Tideglusib enabled scarce porosity, nanoleakage and advanced sealing among dentin groups.

SIGNIFICANCE

Doping hydrophilic polymeric NPs with tideglusib, infiltrated in etched dentin represents a reproducible technique to create reparative dentin at the resin-dentin interface, by inducing therapeutic bioactivity.

Bioprosthetic versus mechanical valves for mitral valve replacement in patients < 70 years: an updated pairwise meta-analysis

BACKGROUND

The ideal conduit for mitral valve replacement (MVR) remains elusive, particularly among younger patients due to increased life expectancy. We perform a pairwise meta-analysis comparing the use of bioprosthetic valves (BPV) and mechanical mitral valves (MMV) in patients < 70 years old undergoing MVR.

METHODS

We comprehensively searched medical databases to identify studies comparing the use of BPV and MMV in patients < 70 years old undergoing MVR. Pairwise meta-analysis was performed using the Mantel-Haenszel method in R version 4.0.2. Outcomes were pooled using the random effect model as risk ratios (RR) with their 95% confidence intervals (95% CI).

RESULTS

16,879 patients from 15 studies were pooled. Compared to MMV, BPV was associated with significantly higher rates of 30-day mortality (RR 1.53, p = 0.0006) but no difference in 30-day stroke (RR 0.70, p = 0.43). At a weighted mean follow-up duration of 14.1 years, BPV was associated with higher rates of long-term mortality (RR 1.28, p = 0.0054). No difference was seen between the two groups for risk of long-term stroke (RR 0.92, p = 0.67), reoperation(RR 1.72, p = 0.12), or major-bleeding (RR 0.57, p = 0.10) at a weighted mean follow-up duration of 11.7, 11.3, and 11.9 years, respectively.

CONCLUSION

The use of MMV in patients < 70 undergoing MVR is associated with lower rates of 30-day/long-term mortality compared to BPV. No significant differences were observed for risk of 30-day/long-term stroke, long-term reoperation, and long-term major bleeding. These findings support the use of MMV in younger patients, although prospective, randomized trials are still needed.

Normative Preclinical Algesiometry Data on the von Frey and Radiant Heat Paw-Withdrawal Tests: An Analysis of Data from More Than 8,000 Mice Over 20 Years

The measurement of withdrawal to experimenter-delivered mechanical stimuli (von Frey test) and to heat stimuli (radiant heat paw-withdrawal or Hargreaves' test) applied to the hind paws is ubiquitous in preclinical pain research, but no normative values for the most-common applications of these tests have ever been published. We analyzed a retrospective data set of withdrawal thresholds or latencies in 8,150 mice in which these measures were taken using replicate determinations, before and after injection of inflammatory substances or experimental nerve damage producing pain hypersensitivity, totaling 97,332 measurements. All mice were tested in the same physical laboratory over a 20-year period using similar equipment and procedures. We nonetheless find evidence of large interindividual variability, affected by tester, genotype, mouse sex, tester sex, replicate order, and injury. These factors are discussed, and we believe that these normative data will serve as a useful reference for expected values in preclinical pain testing. PERSPECTIVE: This article presents a retrospective analysis of a large data set of mouse von Frey and radiant heat paw-withdrawal (Hargreaves' test) measurements collected in a single laboratory over 20 years. In addition to serving as a normative guide, sources of variability are identified including genotype, tester, and sex.

Compensation from mild and severe cases of early proximal junctional kyphosis may manifest as progressive cervical deformity at two year follow-up

BACKGROUND

Postoperative reciprocal changes (RC) in the cervical spine associated with varying factors of proximal junctional kyphosis (PJK) following fusions of the thoracopelvic spine are poorly understood.

PURPOSE

Explore reciprocal changes in the cervical spine associated with varying factors (severity, progression, patient age) of PJK in patients undergoing adult spinal deformity (ASD) correction.

PATIENTS AND METHODS

Retrospective review of a multicenter ASD database.

INCLUSION

ASD patients > 18 y/o, undergoing fusions from the thoracic spine (UIV: T6-T12) to the pelvis with two-year radiographic data. ASD was defined as: Coronal Cobb angle ≥ 20°, Sagittal Vertical Axis ≥ 5 cm, Pelvic Tilt ≥ 25°, and/or Thoracic Kyphosis ≥ 60°. PJK was defined as a ≥ 10° measure of the sagittal Cobb angle between the inferior endplate of the UIV and the superior endplate of the UIV + 2. Patients were grouped by mild (M; 10°-20°) and severe (S; > 20°) PJK at one year. Propensity Score Matching (PSM) controlled for CCI, age, PI and UIV. Unpaired and paired t test analyses determined difference between RC parameters and change between time points. Pearson bi-variate correlations analyzed associations between RC parameters (T4-T12, TS-CL, cSVA, C2-Slope, and T1-Slope) and PJK descriptors.

RESULTS

284 ASD patients (UIV: T6: 1.1%; T7: 0.7%; T8: 4.6%; T9: 9.9%; T10: 58.8%; T11: 19.4%; T12: 5.6%) were studied. PJK analysis consisted of 182 patients (Mild = 91 and Severe = 91). Significant difference between M and S groups were observed in T4-T12 Δ1Y(- 16.8 v - 22.8, P = 0.001), TS-CLΔ1Y(- 0.6 v 2.8, P = 0.037), cSVAΔ1Y(- 1.8 v 1.9, P = 0.032), and C2 slopeΔ1Y(- 1.6 v 2.3, P = 0.022). By two years post-op, all changes in cervical alignment parameters were similar between mild and severe groups. Correlation between age and cSVAΔ1Y(R = 0.153, P = 0.034) was found. Incidence of severe PJK was found to correlate with TS-CLΔ1Y(R = 0.142, P = 0.049), cSVAΔ1Y(R = 0.171, P = 0.018), C2SΔ1Y(R = 0.148, P = 0.040), and T1SΔ2Y(R = 0.256, P = 0.003).

CONCLUSIONS

Compensation within the cervical spine differed between individuals with mild and severe PJK at one year postoperatively. However, similar levels of pathologic change in cervical alignment parameters were seen by two years, highlighting the progression of cervical compensation due to mild PJK over time. These findings provide greater evidence for the development of cervical deformity in individuals presenting with proximal junctional kyphosis.

Risk factors for mechanical complications after fusion extension surgery for lumbar adjacent segment disease

PURPOSE

Adjacent segment disease (ASD) is a common complication in fusion surgery. In the event of solid segmental fusion, previous implants can be removed or preserved during fusion extension for ASD. To compare the surgical outcomes of patients with and without implants and analyzes the risk factors for postoperative mechanical complications.

METHODS

Patients who underwent fusion extension for lumbar ASD from 2011 to 2019 with a minimum 2 year follow-up were retrospectively reviewed. Spinopelvic parameters were measured preoperatively and postoperatively. Clinical outcomes and surgical complications were compared between groups with implants preserved and removed. Risk factors for mechanical complications, including clinical, surgical, and radiographic factors were analyzed.

RESULTS

Sixty-nine patients (mean age, 69.9 ± 6.9 years) were included. The mean numbers of initial and extended fused segments were 2.8 ± 0.7 and 2.7 ± 0.7, respectively. Previous implants were removed in 43 patients (R group) and preserved in 26 patients (P group). Both groups showed an improvement in clinical outcomes without between-group differences. The operation time was significantly longer in R group (260 vs 207 min, p < 0.001). Mechanical complications occurred in 13 patients (12 in R group and 1 in P group) and reoperation was needed in 3 patients (R group). Implant removal, index fusion surgery including L5-S1, and postoperative sagittal malalignment were risk factors for mechanical complications.

CONCLUSION

Implant removal was a risk factor for mechanical complications. Index fusion surgery including L5-S1 and postoperative sagittal malalignment were also risk factors for mechanical complications.

Trends in Isolated Mitral Valve Repair or Replacement Surgery in Australia: A Statewide Cohort Linkage Study

BACKGROUND

Global trends in mitral valve surgery (MVSx) suggest increasing repair compared with replacement, especially in the United States and European countries. The relative use, and outcomes of, MV repair and replacement in Australia are unknown.

METHODS

New South Wales residents who underwent isolated MVSx between 2001 and 2017 were identified from the Admitted-Patient-Data-Collection database. Mortality outcomes were tracked to 31 Dec 2018 and adjusted based on age, sex, urgency of operation, and comorbidity status.

RESULTS

The study cohort comprised 5,693 patients: 2020 (35%) underwent repair (MVr), 1,656 (29%) underwent mechanical replacement (mech.MVR), and 2017 (35%) underwent bioprosthetic replacement (bio.MVR). Respective median ages [interquartile range] were 67 yo [59-75 yo], 64 yo [55-71 yo], and 75 yo [68-80 yo] (p<0.001 across groups). Between 2001 and 2017, total MVSx increased steadily with population growth. Whereas the relative use of MVr remained static (34% to 38%), that for bio.MVR (22% to 50%) and mech.MVR (45% to 13%) changed significantly. MVr had the best outcome with 1.2% in-hospital, 2.5% 1-year, and 21.6% total cumulative mortality during a median follow-up of 6.5 years. Compared to MVr, the adjusted hazard ratio (aHR) for mech.MVR and bio.MVR for long-term mortality were 1.41 (95% confidence interval [CI]=1.24-1.61) and 1.73 (95% CI=1.53-1.95), respectively. Heart failure and sepsis were the main cardiovascular and noncardiovascular causes of death in all groups.

CONCLUSION

In this statewide Australian cohort examined over 17 years, MVr is potentially underutilised despite having superior outcomes to MVR. Access to quality dataset which provides the indication for MVSx and quantitative clinical factors is critical to further improve MVr coverage and outcome MVSx.

A case of stuck mechanical Tricuspid Valve

A 34-year-old non hypertensive, non-diabetic and ill looking weak woman came to our emergency department with shortness of breath NYHA III-IV, severe bilateral pedal edema extending up to the thighs and gross ascites. Physical examination revealed 3mm pitting ankle and leg edema and hemodynamically was stable with raised jugular venous pressure. There was a closing and opening mechanical click on Cardiac auscultation. At the lower left sternal border, there was grade 2/6 holodiastolic rumble and a grade 2/6 systolic murmur. She had history of mitral valve replacement and tricuspid valve replacement in 2017 with mechanical valves then she had Redo tricuspid valve replacement with mechanical prosthesis again after four months. No known food or drug allergy and psychosocial issues. Her routine bloods Labs were normal and COVID-19 was negative. On chest X-ray P/A view images and echo showed markedly gross left sided pleural effusion. In Coronary angiogram showed normal coronaries and stuck tricuspid valve (Fig.1). Echocardiography report showed preserved LV systolic function (EF=57%), dilated left atrium and right atrium. Prosthetic mitral valve was seen at mitral position, well seated and well-functioning. The mechanical mitral valve was functioning well with normal disc motion with no thrombus formation. Prosthetic tricuspid valve was seen at tricuspid level with peak gradient of 22mmHg and shown stuck mechanical tricuspid discs stuck throughout the cardiac cycle, in a fully open position (Fig.2A and 2B). Atrial fibrillation was shown on ECG. The diagnosis was made as; pannus formation resulting in mechanical TV thrombosis.

Preparation and characterization of potato starch-based composite films reinforced by modified banana fibers and its application in packaging of grapes

The current study focuses on the preparation and characterization of potato starch-based biocomposite films by reinforcing them with banana fiber. The banana fibers were modified using ultrasonication and cellulase enzyme, individually and in combination. Both native and modified banana fibers underwent physical, morphological, FTIR, and crystallinity analyses. The resulting biocomposite films, created by incorporating native and treated banana fibers, were then evaluated for their mechanical, thermal, barrier, and biodegradable properties. The findings indicated that combining ultrasound with enzyme treatment of banana fibers in the potato starch matrix led to a substantial reduction in water-sorption and water-vapor permeability (0.156 g mm m-2 h-1 kPa-1) of the packaging films. Additionally, the mechanical properties (5.02 MPa-Tensile strength, 4.27 MPa-Sealability) of the films significantly improved with the inclusion of modified banana fibers. FTIR analysis revealed similar spectra for all modified samples, along with enhanced crystallinity. Moreover, the thermal stability of the developed films was enhanced by the incorporation of modified banana fibers. Scanning electron microscopy showed that the modified fibers exhibited smooth surfaces and an even distribution of spaces compared with the native fibers. The biocomposite films demonstrated biodegradation within 42 days. Furthermore, the packaging application was tested with grapes, which showed that the films could maintain storability for up to 8 days. Overall, these results suggest a promising eco-friendly method for producing packaging films with biocompatible, biodegradable, and non-toxic properties.

Exploring the Biomedical Potential of PLA/Dysprosium Phosphate Composites via Extrusion-Based 3D Printing: Design, Morphological, Mechanical, and Multimodal Imaging and Finite Element Modeling

The present investigation demonstrates the feasibility of dysprosium phosphate (DyPO4) as an efficient additive in polylactide (PLA) to develop 3D printed scaffolds through the material extrusion (MEX) principle for application in bone tissue engineering. Initially, uniform sized particles of DyPO4 with tetragonal crystal setting are obtained and subsequently blended with different concentrations of PLA to extrude in the form of filaments. A maximum of 20 wt % DyPO4 in PLA matrix has been successfully drawn to yield a defect free filament. The resultant filaments were 3D printed through material extrusion methodology. The structural and morphological analysis confirmed the successful reinforcement of DyPO4 throughout the PLA matrix in all of the 3D printed components. All of the PLA/DyPO4 composites exhibited magnetic resonance imaging and computed tomography contrasting properties, which were dependent on the dysprosium content in the PLA matrix. The detailed mechanical evaluation of the 3D printed PLA/DyPO4 composites ensured good strength accomplished by the reinforcement of 5 wt % DyPO4 in PLA matrix, beyond which a gradual decline in the strength is noticed. Representative volume elements models were developed to realize the intrinsic property of the PLA/DyPO4 composite, and finite element analysis under both static and dynamic loading conditions has been performed to account for the reliability of experimental results.

Mechanical properties and wound healing potential of bacterial cellulose-xyloglucan-dextran hydrogels

Bacterial cellulose (BC) is a promising material for use as an artificial skin in wound healing application, however, its applications are limited due to its poor malleability. Incorporating non-cellulosic polysaccharides such as dextran and xyloglucan (XG) may enhance its respective wound healing and malleability. This study presents a novel in situ biopreparation method to produce BC-based hybrid hydrogels containing dextran (BC-D) and xyloglucan-dextran (BC-XG-D) with unique mechanical and rheological properties. Structural analysis revealed that dextran of different sizes (10 k, 70 k and 2 M of Mw) form micron-sized particles by loosely binding to cellulosic fibres. The addition of xyloglucan resulted acts as a lubricant in mechanical testing. The BC-XG-D hybrid hydrogels showed a reduced Young's modulus of 4 MPa and a higher maximum tensile strain of 53 % compared to native BC. Moreover, they displayed less plastic but more viscous behaviour under large shear strain deformation. The wound healing animal model experiments demonstrated that the BC-XG-D hybrid hydrogels promoted wound healing process and skin maturation. Overall, these findings contribute to the development of functional BC-based medical materials with desired mechanical and rheological properties that have the potential to accelerate wound healing.

A New Concept of Using Femoral Condyles Surface for Femoral Component Alignment During Total Knee Arthroplasty: A Technical Note

Background

Orthopedic surgeons favor an intramedullary guiding system on the femoral component during total knee arthroplasty (TKA); nevertheless, improper positioning of the entry point affects the final alignment. We have designed a new femoral cutting system for TKA that uses the distal and posterior femoral condyles as reference points for the setting of the cutting system regardless of the femoral canal. This study aims to evaluate the outcomes of this new guiding system.

Methods

We enrolled a series of 75 consecutive knees undergoing TKA. The alpha, gamma, and hip-knee-ankle (HKA) angles were assessed three months postoperatively. Also, surgical time and intraoperative blood loss were recorded for all patients.

Results

Fifteen patients underwent TKA using the mechanical alignment (MA) strategy, and 60 underwent kinematically aligned (KA) TKA. Both groups showed normal coronal and sagittal alignment 3 months postoperatively. The mean intraoperative blood loss was 213.11 ± 52.73 ml, which was not different between the two groups (n.s.). The mean surgical time was 43.12 ± 11.62 min, which was significantly shorter in the KA-TKA (41.11 ± 3.77 min) than in the MA-TKA (49.34 ± 4.56 min) (P < 0.001).

Conclusion

Using the new guiding system with good femoral alignment, we introduced the easily palpable and available condylar surface as a new landmark for cutting the distal femur in TKA.

Level of Evidence

IV.

Outcomes after Mechanical Aortic Valve Replacement in Children with Congenital Heart Disease

Background

The optimal choice of valve substitute for aortic valve replacement (AVR) in pediatric patients remains a matter of debate. This study investigated the outcomes following AVR using mechanical prostheses in children.

Methods

Forty-four patients younger than 15 years who underwent mechanical AVR from March 1990 through March 2023 were included. The outcomes of interest were death or transplantation, hemorrhagic or thromboembolic events, and reoperation after mechanical AVR. Adverse events included any death, transplant, aortic valve reoperation, and major thromboembolic or hemorrhagic event.

Results

The median age and weight at AVR were 139 months and 32 kg, respectively. The median follow-up duration was 56 months. The most commonly used valve size was 21 mm (14 [31.8%]). There were 2 in-hospital deaths, 1 in-hospital transplant, and 1 late death. The overall survival rates at 1 and 10 years post-AVR were 92.9% and 90.0%, respectively. Aortic valve reoperation was required in 4 patients at a median of 70 months post-AVR. No major hemorrhagic or thromboembolic events occurred. The 5- and 10-year adverse event-free survival rates were 81.8% and 72.2%, respectively. In univariable analysis, younger age, longer cardiopulmonary bypass time, and smaller valve size were associated with adverse events. The cut-off values for age and prosthetic valve size to minimize the risk of adverse events were 71 months and 20 mm, respectively.

Conclusion

Mechanical AVR could be performed safely in children. Younger age, longer cardiopulmonary bypass time and smaller valve size were associated with adverse events. Thromboembolic or hemorrhagic complications might rarely occur.

Effects of an MDP-based surface cleaner on dentin structure, morphology and nanomechanical properties

OBJECTIVE

To analyze the effect of Katana™ Cleaner (KC) in nanomechanical and triboscopic properties of etched dentin.

METHODS

Dentin disks from human third molars were prepared. Two main groups of study were established in function of the etching conditioning, phosphoric acid (PA) and Clearfil SE Bond primer (CSEB). Four subgroups were tested within each group: i) untreated dentin (UD), ii) etched dentin (ED) [(PAED/CSEB)], iii) etched dentin contaminated with saliva (PAED+S)/(CSEB+S), and iv) etched and contaminated dentin treated with KC (PAED+S+KC)/(CSEB+S+KC). Nano-DMA testing and imaging, atomic force microscopy (AFM) analysis and nanoroughness (SRa) measurements were obtained. Field emission scanning electron microscopy (FESEM) images were also acquired.

RESULTS

Phosphoric acid etched dentin samples and those specimens contaminated with saliva (PAED+S) attained the highest SRa values, that decreased after Katana™ Cleaner application (PAED+S+KC). In the group of dentin treated with CSEB primer, all subgroups performed similar, except in CSEB+S that attained the highest SRa values. The treatment with KC restored the original values of complex modulus of the untreated dentin. KC application produced the lowest and the highest tan delta values on PAED and CSEB groups, respectively.

CONCLUSION

Katana™ Cleaner provided equally mature dentin surfaces after any of the etching methods. Tan delta increased when Katana™ Cleaner was applied on the dentin surface previously etched and contaminated with saliva, regardless the kind of etchant, thus facilitating the dissipation of energy for elastic recoil during loading.

CLINICAL SIGNIFICANCE

Katana™ Cleaner application after saliva contamination originated similar low roughness levels, regardless the type of etching method. Both complex and storage moduli were similar, after Katana™ Cleaner application, in any case.

A study on mechanical and tribological properties of eco-friendly synthesized ZrO2-doped borosilicate glasses

The research article aims to investigate the mechanical and tribological characteristics of bioactive glass specimens comprising 31B2O3-20SiO2-24.5Na2O-(24.5-x) CaO and xZrO2 (mol%). This glass system was partially derived from bio-waste, with varying concentrations of Zirconia (ZrO2) represented x (x = 0, 1, 3, and 5). The specimens were fabricated using the traditional melt-quench method. Mechanical studies like hardness and compressive strength were measured using Vickers hardness tester and universal tensile machine respectively, while a pin-on-disk tribometer was used to analyze the tribological characteristics. All the specimens were soaked in SBF for a week to assess in-vitro bioactivity. The research findings indicate that Zirconia inclusion resulted in a significant reduction in the intensity of hydroxyapatite peaks of FTIR and XRD spectra, suggesting a decrease in bioactivity. However, it concurrently resulted in increased glass hardness, with the highest value (∼7.55 GPa) observed in the BSG-5 glass sample. Similarly, compressive strength results demonstrated maximum strength in BSG-5 glass specimen, with a value of approximately ∼132 MPa. Moreover, the tribological properties of the glass system were enhanced, evident from the reduced coefficient of friction and specific wear rate. Notably, the BSG-5 glass specimen exhibited the least wear coefficient of 0.018 mm3/N-m at a track radius of 40 mm and a load of 15N. These findings were further supported by SEM images of the worn-out ZrO2-Doped Borosilicate Glass surface. Overall, the results suggest that the addition of Zirconia to borosilicate glass holds promise for improving its mechanical and tribological characteristics. However, this enhancement comes at the expense of its bioactivity. Consequently, the modified glass system presents a cost effective viable option for various applications, particularly in load-bearing and dental applications.

Development, Physiochemical characterization, Mechanical and Finite element analysis of 3D printed Polylactide-β-TCP/α-Al2O3 composite

Herein, material extrusion (MEX) technique is utilized to develop 3D printed models based on reinforcing β-Ca3(PO4)2/α-Al2O3 composite in polylactide (PLA) matrix. β-Ca3(PO4)2/α-Al2O3 composite has been synthesized through co-precipitation method and the phase content of β-Ca3(PO4)2 and α-Al2O3 components are respectively determined as 64 and 36 wt%. The resultant β-Ca3(PO4)2/α-Al2O3 composite mixed with PLA at various weight ratios were extruded as filaments and subsequently 3D printed into definite shapes for the physiochemical, morphological and mechanical evaluation. 3D printed bodies that comprise 5 wt % β-Ca3(PO4)2/α-Al2O3 composite yielded an increasing tensile, compressive and flexural strength in the corresponding order of ∼15, ∼15 and 22% than 3D printed pure PLA. Further, the Representative volume element (RVE) unit cells developed based on the various investigated compositions of PLA-β-Ca3(PO4)2/α-Al2O3 were subjected to mechanical evaluation through Finite element analysis (FEA) under both static and dynamic loading conditions on ASTM standard specimens. The results from experimental and FEA analysis demonstrated good uniformity that confirmed the reinforcement of 5 wt % β-Ca3(PO4)2/α-Al2O3 in PLA matrix as an optimum combination to yield better mechanical strength.

Exploration of the structural, optoelectronic, magnetic, elastic, vibrational, and thermodynamic properties of molybdenum-based chalcogenides A2MoSe4 (A =Li, K) for photovoltaics and spintronics applications: a first-principle study

CONTEXT

In the present work, the cubic phase of the chalcogenide materials, i.e., A2MoSe4 (A =Li, K) is examined to explore the structural, optoelectronic, magnetic, mechanical, vibrational, and thermodynamic properties. The lattice parameters for Li2MoSe4 are found to be a= 7.62 Å with lattice angles of α=β=γ=90° whereas for K2MoSe4, a= 8.43 Å, and α=β=γ=90°. These materials are categorized as semiconductors because Li2MoSe4 and K2MoSe4 exhibit direct energy band gap worth 1.32 eV and 1.61 eV, respectively through HSE06 functional. The optical analysis has declared them efficient materials for optoelectronic applications because both materials are found to be effective absorbers of ultraviolet radiations. These materials are noticed to be brittle while possessing anisotropic behavior for various mechanical applications. The vibrational properties are explored to check the thermal stability of the materials. On the basis of thermodynamics and heat capacity response, Li2MoSe4 is more stable than K2MoSe4. The results of our study lay the groundwork for future research on the physical characteristics of ternary transition metal chalcogenides (TMC).

METHODS

These physical properties are explored for the first time while using a first-principles approach based on density functional theory (DFT) in the framework of Cambridge Serial Total Energy Package (CASTEP) by Perdew-Burke-Ernzerhof generalized gradient approximation (PBE-GGA) functional. However, GGA+U and HSE06 are also employed to improve electronic properties. Kramers-Kronig relations are used to evaluate the dielectric function with a smearing value of 0.5 eV. Voigt-Reuss-Hill approximation is used for seeking the elastic response of these materials. The thermodynamic response is sought by harmonic approximation. The density functional perturbation theory (DFPT) approach is used for investigating atomic vibrations.

Simulating dispersion of oils from a subsea release comparing mechanical and chemically enhanced dispersion - An experimental study of the influence of oil properties

The main objective with subsea mechanical dispersion (SSMD) is to influence the fate of an oil spill in the marine environment by significantly reducing oil droplet sizes from subsea release of oil. Earlier studies have indicated that the capability of SSMD to reduce oil droplet sizes is comparable to subsea dispersant injection (SSDI). Earlier testing of SSMD has mainly used a low viscus paraffinic oil. Focus for this study was to study SSMD and SSDI effectiveness using five oil types spanning out a wide variation of relevant oil properties. Effectiveness was quantified as the reduction in oil droplet sizes measured by a Silhouette camera. Testing of the two technologies were completed in the same experiment on a simulated subsea release. The results show a variation in effectiveness for both technologies as a function of oil properties. SSMD and SSDI showed comparable effectiveness for all oils tested.

Synthesis, In silico mapping for anti-cancer proviso, hardness studies of d-gluconic acid monohydrate crystals for usage in electronic, mechanical and biological sectors

d-Gluconic acid monohydrate - DGAMH crystals are grown in a period of 61 days by using the customary slow evaporation method with a, b and c as 8.4309, 5.409 and 10.4071 in Å units; β as 96.87°; monoclinic system, space group as P21. The material is an anticancer stipulation to inhibit them with the docked score of the DGAMH as -6.0 and -7.1 for both cases. Considering the mechanic behaviour of the DGAMH; the n as 7.57 of the DGAMH - work hardening coefficient value as Reverse ISE (indentation size effect) response for DGAMH. The computational structural info of DGAMH provides the supercell proviso, VanderWaal's impact with the nano-tubular proviso of DGAMH for cell impacting, weak type of interactions and devices with nano-tube impact. The electronic fluxing is in microns for macro-DGAMH; micro-DGAMH; thin-film DGAMH and nano-DGAMH for filtering property confirmations. The frequency by IC741 is twice over the input values with DGAMH crystal.

Synergetic effects of boron nitride with waste zirconia: Evaluation of instantaneous fingerprint detection and mechanical properties for biomedical applications

Herein, present study mainly focuses on the synthesis and characterizations of boron nitride reinforced waste zirconia (wZrO2) with different concentrations. Composites were prepared via a scalable solid-state reaction method. Various physical parameters such as density, ionic concentration, polaron radius, and field strength were evaluated. XRD results reveal crystalline nature with a major phase of tetragonal zirconia and as boron nitride is reinforced, the tetragonal transforms into a monoclinic zirconia. Interconnected spherical grains and nanosheets were observed using FESEM. Mechanical characterizations revealed the highest compressive strength of 266 MPa. The latent fingerprints were visualized using a composite on different surfaces, implementing the powder dusting and solution techniques. MTT assay was performed and revealed good biocompatible nature. These results reveal that composite is suitable for fabrication of bioceramics with acceptable mechanical and biological performances. The composite can also be utilized for latent fingerprint detection in forensic science.

Unilateral acquired blepharoptosis due to orbital metastatic disease as an initial presentation of an overlooked breast carcinoma - A case report

INTRODUCTION AND IMPORTANCE

Orbital metastasis from breast cancer may be infrequently noted after the management of the primary lesion. It is rare in such cases to present with unilateral mechanical blepharoptosis without ophthalmoplegia.

CASE PRESENTATION

We present a case of unilateral acquired blepharoptosis of the left upper eyelid without ophthalmoplegia or exophthalmos three years after the onset of a suspicious breast mass. The patient did not disclose a history of breast cancer nor any positive family history to the ophthalmologist and anesthesiologist. The radiology images revealed an ill-defined enhanced lesion at the superior medial aspect of the left orbit. The orbital biopsy of the lesion showed poorly differentiated carcinoma as per the initial histopathology report. Vigilant history-taking enabled us to get information about a previous breast lesion and to correlate this with specific histopathological findings.

DISCUSSION

Management of orbital lesions might be challenging, and the approach should include detailed history and assessment. Biopsy and radio imaging are further needed to aid in providing the proper diagnosis. The clinicopathological correlation in our case has led to the final diagnosis of orbital metastatic breast cancer.

CONCLUSION

Ophthalmologists should be aware of variable ocular presentations of malignancy and adopt a team approach to obtain a carefully detailed history from patients presenting with orbital diseases and communicate adequately with the ocular pathologists who are handling the biopsy. Long-term follow-up and enhancement of patients' awareness of possible late orbital metastasis are recommended in all patients with breast masses.

Mechanical properties of an elastically deformable cervical spine implant

Anterior cervical surgery is widely accepted and time-tested surgical procedure for treating cervical radiculopathy and myelopathy. However, there is concern about the high adjacent segment degeneration rate and implant subsidence after the surgery using the traditional polyetheretherketone cage. Thus, we creatively designed a polyurethane cervical implant that can continuous load-sharing through elastic deformation and decrease postoperative stress concentration at adjacent segments. In this study, the design rationality and safety of this novel implant was evaluated based on several mechanical parameters including compression test, creeping test, push-out test and subsidence test. The results showed that the novel cervical implant remained intact under the compressive axial load of 8000 N and continues to maintained the elastic deformation phase. The minimum push-out load of the implant was 181.17 N, which was significantly higher than the maximum compressive shear load of 20 N experienced by a normal human cervical intervertebral disc. Besides, the creep recovery behaviour of the implant closely resembled what has been reported for natural intervertebral discs and clinically applied cervical devices in literature. Under the load of simulating daily activities of the cervical spine, the implant longitudinal displacement was only 0.54 mm. In conclusion, this study showed that the current design of the elastically deformable implant was reasonable and stable to fulfil the mechanical requirements of a cervical prosthesis under physiological loads. After a more comprehensive understanding of bone formation and stress distribution after implantation, this cervical implant is promising to be applied to certain patients in clinical practice.

Shear's role in non-union. Measuring mean angle of long bone multi-fragmentary non-unions

INTRODUCTION

Both mechanical and biological theories have been proposed in the development of non-union. The mechanical theory suggests that a high strain environment in a fracture will predispose it to non-union. While in simple fractures and wedge fractures there are only one and two primary fracture planes respectively, in multi-fragmentary fractures there are many and a non-union may form along any of the original fracture lines, however the plane which experiences the highest strain is at 45O - the shear plane. We hypothesise that in multi-fragmentary fractures the initial fracture line that most often fails to unite will tend towards the plane with the highest strain.

OBJECTIVES

1) Define the mean non-union angle in a cohort of multi-fragmentary tibial and femoral fractures. 2) In wedge-like fractures within the cohort, define and compare the mean angle of initial fracture planes which go on to form a non-union to those that unite 3) In comminuted fractures within the cohort, define the mean non-union angle DESIGN: Retrospective cohort study SETTING: Level-1 trauma centre METHODOLOGY: Fractures were categorised into wedge-like and comminuted. A published technique was utilised to measure fracture and non-union angles. In wedge-like fractures, united and non-united initial planes were compared. In comminuted fractures only the mean non-union angle was defined. Demographic patient data was also collected.

RESULTS

183 non-unions were screened, 68 patients were included. The mean non-union angle was 56°(SD 18) across all fractures. In wedge-like fractures the mean non-union angle was 59°(SD 18). In comminuted fractures the mean non-union angle was 50°(SD 19). Non-united initial fracture planes in wedge-like fractures showed a peaked distribution about a mean of 58° while united fracture planes were distributed at the extremities of the range.

CONCLUSIONS

In patients with multi-fragmentary fractures resulting in non-union, the mean tibial non-union angle was 52° while the mean femoral non-union angle was 65°. In wedge-like fractures, non-unions occurred more commonly than appropriate union in fractures between 41°-80°. The non-union angle is closer to 45° in comminuted fractures than in wedge-like fractures. These results support the mechanical theory that strain from the shear plane is an important factor in the formation of non-unions.

LEVEL OF EVIDENCE

Prognostic level 3.

Reducing oil droplet sizes from a subsea oil and gas release by water jetting a laboratory study performed at different scales

The main objective of subsea mechanical dispersion (SSMD) is to reduce the oil droplet sizes from a subsea oil release, thereby influencing the fate and behaviour of the released oil in the marine environment. Subsea water jetting was identified as a promising method for SSMD and imply that a water jet is used to reduce the particle size of the oil droplets initially formed from the subsea release. This paper presents the main findings from a study including small-scale testing in a pressurised tank, via laboratory basin testing, to large-scale outdoor basin testing. The effectiveness of SSMD increases with the scale of the experiments. From a five-fold reduction in droplet sizes for small-scale experiments to more than ten-fold for large-scale experiments. The technology is ready for full-scale prototyping and field testing. Large-scale experiments performed at Ohmsett indicate that SSMD could be comparable to subsea dispersant injection (SSDI) in reducing oil droplet sizes.

An ab-initio study of P-type ZrCoY (Y[bond, double bond]Sb and Bi) half - Heusler semiconductors

In this study, the structural, electronic, mechanical, optical, and thermoelectric properties of the cubic half-Heusler compound ZrCoY(Y[bond, double bond]Sb and Bi) obtained using first-principles calculations are presented. The following exchange-correlation functionals have been employed: Generalized Gradient Approximation with Perdew-Burke-Ernzerhoff (GGA-PBE), Generalized Gradient Approximation with Perdew-Burke-Enzerhoff for solids (GGA-PBESol) and Local Density Approximation (LDA). Both ZrCoSb and ZrCoBi compounds are mechanically and dynamically stable, based on the elastic and phonon properties analysis. The calculated electronic band gaps for both compounds are about 1 eV, as predicted by all the three functionals. Since it is noted that GGA-PBE functional is most favourable for predicting structural properties and the energetic stability of ZrCoSb and ZrCoBi compounds, it is further used to calculate their thermoelectric properties. Within the energy range of 0-40 eV, the refractive index, dielectric constant, and energy loss function of ZrCoSb and ZrCoBi compounds are calculated. The possibility of electronic transition from the valence band maximum (VBM) to the conduction minimum band (CBM) is confirmed by the occurrence of absorption peaks in the visible range. For the evaluation of thermoelectric properties, the p-type and n-type doping attained Seebeck coefficients of 1800 and -1800 μVK-1 at 300 K, respectively. The maximum peak of 17 × 1011 W/m s K2 is attained in n-type doping, according to the power factor results.

Influence of phase-separated structural morphologies on the piezo and triboelectric properties of polymer composites

Simplified and flexible fabrication methods, high output performance, and extreme flexibility of polymer-based nanocomposites represent versatile designs in self-powering devices for wearable electronics, sensors, and smart societies. Examples include polyvinylidene fluoride and its copolymers-based piezoelectric nanogenerators, green and recyclable triboelectric nanogenerators, etc. Advanced functionalities, multi-functional properties, and the extensive lifetime required for nanogenerators inspire researchers to focus on structural modifications of the polymeric materials, to fully exploit their performances. Phase separation is a physicochemical process in which polymeric phases rearrange, resulting in specific structures and properties, that ultimately influence mechanical, electronic, and other functional properties. This article will study the phase separation strategies used to modify the polymeric base, both physically and chemically, to generate the maximum electric power upon mechanical and frictional deformation. The effect of interfacial modification on the efficiency of the nanogenerators, chemical and mechanical stability, structural integrity, durable performance, and morphological appearance will be extensively covered in this review. Moreover, piezo- and triboelectric power generation have numerous challenges, such as poor resistance to mechanical deformation, reduced cyclic performance stability, and a high cost of production. These often depend on the method of developing the nanogenerators, and phase separation provides a unique advantage in reducing them. The current review provides a one-stop solution to understand and disseminate the phase separation process, types and mechanisms, advantages, and role in improving the piezoelectric and triboelectric performances of the nanogenerators.

Revision surgery following long lumbopelvic constructs for adult spinal deformity: prospective experience from two dedicated databases

PURPOSE

Pan Lumbar Arthodesis (PLA) are often required for Adult Spinal Deformity (ASD) correction, reducing significantly the compensatory capacity in case of postoperative sagittal malalignment. Few papers have investigated outcomes and complications in this vulnerable subset of patients. The objective of this study was to assess revision surgery rate for PLA in ASD, its risk factors and impact on clinical outcomes.

METHODS

Retrospective multicenter review of prospective ASD data from 7 hospitals covering Europe and Asia. ASD patients included in two prospective databases having a posterior instrumentation spanning the whole lumbar region with more than 2-years of follow-up were reviewed. Demographic, surgical, radiographic parameters and Health-Related Quality of Life (HRQoL) scores were analyzed. Univariate and multivariate regression models analyzed risk factors for revision surgery as well as surgical outcomes. Patients with Early versus Late and PJK versus Non-PJK mechanical complications were also compared.

RESULTS

Out of 1359 ASD patients included in the database 589 (43%) had a PLA and 357 reached 2-years mark. They were analyzed and compared to non-PLA patients. Average age was 67 and 82% were females. 100 Patients (28.1%) needed 114 revision surgeries (75.4% for mechanical failures). Revised patients were more likely to have a nerve system disorder, higher BMI and worst immediate postoperative alignment (as measured by GAP Parameters). These risk factors were also associated with earlier mechanical complications and PJK. Deformity and HRQoL parameters were comparable at baseline. Non-revised patients had significantly better clinical outcomes at 2-years (SRS 22 scores, ODI, Back pain). Multivariate analysis could identify nerve system disorder (OR 4.8; CI 1.8-12.6; p = 0.001), postoperative sagittal alignment (GAP Score) and high BMI (OR 1.07; CI 1.01-1.13; p = 0.004) as independent risk factors for revisions.

CONCLUSIONS

Revision surgery due to mechanical failures is relatively common after PLA leading to worse clinical outcomes. Prevention strategies should focus on individualized restoration of sagittal alignment and better weight control to decrease stress on these rigid constructs in non-compliant spines. Nerve system disorders independently increase revision risk in PLA.

LEVEL OF EVIDENCE II

Prognosis.

Mechanical complications of hip spacers: a systematic review of the literature

INTRODUCTION

Temporary spacers used in the staged revision of a hip prosthetic joint infection (PJI) have been associated with several mechanical complications with very variable reported general complications rates up to 73%. The aim of this systematic review was to assess the mechanical complications associated with hip antibiotic-loaded spacers when treating periprosthetic hip PJI.

METHODS

Through an electronic systematic search of PubMed, articles reporting mechanical complications of spacers used in the treatment of hip PJI were reviewed. Dislocations, spacer fracture, femoral fractures, and acetabular lysis rates were evaluated.

RESULTS

Forty studies were included. Standardized molded spacers had a significantly higher weighted mean of total mechanical complication rates (37.2%) when compared to standardized preformed spacers (13.8%, p = 0.039), while no significant difference was found between molded spacers and manually shaped spacers. Spacer dislocation was the most frequent complication. No significant difference in mechanical complication rate was found between spacers with and without any metallic component.

CONCLUSIONS

Spacer placement in chronic PJI of the hip with bone and soft-tissue defects is challenging and bears a high risk of mechanical failures and progressive bone loss during the interim period. A careful patient selection for spacer implantation is mandatory.

Exploration of muscle-tendon biomechanics one year after Achilles tendon rupture and the compensatory role of flexor hallucis longus

Achilles tendon (AT) rupture leads to long-term structural and functional impairments. Currently, the predictors of good recovery after rupture are poorly known. Thus, we aimed to explore the interconnections between structural, mechanical, and neuromuscular parameters and their associations with factors that could explain good recovery in patients with non-surgically treated AT rupture. A total of 35 patients with unilateral rupture (6 females) participated in this study. Muscle-tendon structural, mechanical, and neuromuscular parameters were measured 1-year after rupture. Interconnections between the inter-limb differences (Δ) were explored using partial correlations, followed by multivariable linear regression to find associations between the measured factors and the following markers that indicate good recovery: 1) tendon length, 2) tendon non-uniform displacement, and 3) flexor hallucis longus (FHL) normalized EMG amplitude difference between limbs. Δmedial gastrocnemius (MG) (β = -0.12, p = 0.007) and Δlateral gastrocnemius (β = -0.086, p = 0.030) subtendon lengths were associated with MG tendon Δstiffness. MG (β = 11.56, p = 0.003) and soleus (β = 2.18, p = 0.040) Δsubtendon lengths explained 48 % of variance in FHL EMG amplitude. Regression models for tendon length and non-uniform displacement were not significant. Smaller inter-limb differences in Achilles subtendon lengths were associated with smaller differences in the AT stiffness between limbs, and a smaller contribution of FHL muscle to the plantarflexion torque. In the injured limb, the increased contribution of FHL appears to partially counteract a smaller contribution from MG due to the elongated tendon, however the role of FHL should not be emphasized during rehabilitation to allow recovery of the TS muscles.

Boron nitride decorated poly(vinyl alcohol)/poly(acrylic acid) composite nanofibers: A promising material for biomedical applications

In this study, polyvinyl alcohol (PVA) and polyacrylic acid (PAA) nanofibers loaded with boron nitride nanoparticles (mBN) were fabricated by using electrospinning and crosslinked by heat treatment. The physical, chemical, and mechanical properties, hydrophilic behavior, and degradability of composite nanofibers were evaluated. The mechanical properties such as elastic modulus, elongation percentage at the break, and mechanical strength of PVA/PAA nanofibers improved with mBN loading. The thermal conductivity of composite nanofibers reached 0.12 W/m·K at mBN content of 1.0 wt% due to the continuous heat conduction pathways of mBN. In the meantime, while there was no cytotoxicity recorded for both L929 and HUVEC cell lines for all composite nanofibers, the antimicrobial efficiency improved with the incorporation of mBN compared with PVA/PAA and recorded as 68.8% and 75.1% for Escherichia coli and Staphylococcus aureus, respectively. On this basis, the present work proposes a promising biomaterial for biomedical applications such as dual drug delivery, particularly including both hydrophobic and hydrophilic drugs or wound dressing.

Challenges and perspectives of multi-virus biosensing techniques: A review

In the context of globalization, individuals have an increased chance of being infected by multiple viruses simultaneously, thereby highlighting the importance of developing multiplexed devices. In addition to sufficient sensitivity and rapid response, multi-virus sensing techniques are expected to offer additional advantages including high throughput, one-time sampling for parallel analysis, and full automation with data visualization. In this paper, we review the optical, electrochemical, and mechanical platforms that enable multi-virus biosensing. The working mechanisms of each platform, including the detection principle, transducer configuration, bio-interface design, and detected signals, are reviewed. The advantages and limitations, as well as the challenges in implementing various detection strategies in real-life scenarios, were evaluated. Future perspectives on multiplexed biosensing techniques are critically discussed. Earlier access to multi-virus biosensors will efficiently serve for immediate pandemic control, such as in emerging SARS-CoV-2 and monkeypox cases.

Current Challenges in Chronic Ankle Instability: Review and Perspective

Chronic ankle instability (CAI) is common, disabling, and represents a significant socioeconomic burden. Current treatment options are not adequately efficacious. CAI is multifaceted, yet it is commonly addressed in terms of either mechanical instability or functional impairment. Both are inherently linked. Basic research must be conducted to foster reliable translational research encompassing both mechanical and functional aspects. A review was conducted to identify CAI risk factors for inclusion in future studies, and we offer here opinions and perspectives for future research.

Dexamethasone-doped nanoparticles improve mineralization, crystallinity and collagen structure of human dentin

OBJECTIVES

Bioactive materials have been used for functionalization of adhesives to promote dentin remineralization. This study aims to evaluate bonding ability and both mechanical and chemical behavior of demineralized dentin infiltrated with polymeric nanoparticles doped with dexamethasone (Dex-NPs).

METHODS

Dentin conditioned surfaces were infiltrated with NPs, Dex-NPs or Dex-Zn-NPs. Bonded interfaces were also created and stored for 24 h or 21d, and then submitted to microtensile bond strength testing. Dentin remineralization was analyzed by Nanohardness, Young's modulus and Raman analysis.

RESULTS

At 21d of storage, dentin treated with undoped-NPs attained the lowest nanohardness and Young's modulus. Dex-NPs and Zn-Dex-NPs increased dentin nanohardness and Young's modulus after 21d Raman analysis showed high remineralization, crystallinity, crosslinking and better structure of collagen when functionalized Dex-NPs were present at the dentin interface.

CONCLUSIONS

Infiltration of dentin with Dex-NPs promoted functional remineralization as proved by nanomechanical and morpho-chemical evaluation tests. Dexamethasone in dentin facilitated crystallographic maturity, crystallinity and improved maturity and secondary structure of dentin collagen.

CLINICAL SIGNIFICANCE

Using dexamethasone-functionalized NPs before resin infiltration is a clear option to obtain dentin remineralization, as these NPs produce the reinforcement of the dentin structure, which will lead to the improvement of the longevity of resin restorations.

The impact of different alignment strategies on bone cuts in total knee arthroplasty for varus knee phenotypes

PURPOSE

The purpose of this study was to visualise the influence of alignment strategy on bone resection in varus knee phenotypes. The hypothesis was that different amounts of bone resection would be required depending on the alignment strategy chosen. Through visualisation of the corresponding bone sections, it was hypothesised, it would be possible to assess which of the different alignment strategies would require the least amount of change to the soft tissues for the chosen phenotype, whilst still ensuring acceptable alignment of the components, and thus could be considered the most ideal alignment strategy.

METHODS

Simulations of the different alignment strategies (mechanical, anatomical, constrained kinematic and unconstrained kinematic) in relation to their bone resections were performed on five common exemplary varus knee phenotypes. VAR_HKA174° VAR_FMA87° VAR_TMA84°, VAR_HKA174° VAR_FMA90° NEU_TMA87°, VAR_HKA174° NEU_FMA93° VAR_TMA84°, VAR_HKA177° NEU_FMA93° NEU_TMA87° and VAR_HKA177° VAL_FMA96° VAR_TMA81°. The phenotype system used categorises knees based on overall limb alignment (i.e. hip knee angle) but also takes into account joint line obliquity (i.e. TKA and FMA) and has been applied in the global orthopaedic community since its introduction in 2019. The simulations are based on long-leg radiographs under load. It is assumed that a change of 1° in the alignment of the joint line corresponds to a displacement of the distal condyle by 1 mm.

RESULTS

In the most common phenotype VAR_HKA174° NEU_FMA93° VAR_TMA84°, a mechanical alignment would result in an asymmetric elevation of the tibial medial joint line by 6 mm and a lateral distalisation of the femoral condyle by 3 mm, an anatomical alignment only by 0 and 3 mm, a restricted by 3 and 3 mm, respectively, whilst a kinematic alignment would result in no change in joint line obliquity. In the similarly common phenotype 2 VAR_HKA174° VAR_FMA90° NEU_TMA87° with the same HKA, the changes are considerably less with only 3 mm asymmetric height change on one joint side, respectively, and no change in restricted or kinematic alignment.

CONCLUSION

This study shows that significantly different amounts of bone resection are required depending on the varus phenotype and the alignment strategy chosen. Based on the simulations performed, it can, therefore, be assumed that an individual decision for the respective phenotype is more important than the dogmatically correct alignment strategy. By including such simulations, the modern orthopaedic surgeon can now avoid biomechanically inferior alignments and still obtain the most natural possible knee alignment for the patient.

The end-tidal alveolar dead space fraction for risk stratification during the first week of invasive mechanical ventilation: an observational cohort study

BACKGROUND

The end-tidal alveolar dead space fraction (AVDSf = [PaCO₂-P_ETCO₂]/PaCO₂) is a metric used to estimate alveolar dead space. Higher AVDSf on the first day of mechanical ventilation is associated with mortality and fewer ventilator-free days. It is not clear if AVDSf is associated with length of ventilation in survivors, how AVDSf performs for risk stratification beyond the first day of ventilation, or whether AVDSf adds predictive value to oxygenation (oxygenation index [OI]) or severity of illness (Pediatric Risk of Mortality [PRISM III]) markers.

METHODS

Retrospective single-center observational cohort study of children and young adults receiving invasive mechanical ventilation. In those with arterial or capillary blood gases, AVDSf was calculated at the time of every blood gas for the first week of mechanical ventilation.

RESULTS

There were 2335 children and young adults (median age 5.8 years [IQR 1.2, 13.2]) enrolled with 8004 analyzed AVDSf values. Higher AVDSf was associated with mortality and longer length of ventilation in survivors throughout the first week of ventilation after controlling for OI and PRISM III. Higher OI was not associated with increased mortality until ≥ 48 h of ventilation after controlling for AVDSf and PRISM III. When using standardized variables, AVDSf effect estimates were generally higher than OI for mortality, whereas OI effect estimates were generally higher than AVDSf for the length of ventilation in survivors. An AVDSf > 0.3 was associated with a higher mortality than an AVDSf < 0.2 within each pediatric acute respiratory distress syndrome severity category. The maximum AVDSf within 12 h of intensive care unit admission demonstrated good risk stratification for mortality (AUC 0.768 [95% CI 0.732, 0.803]). AVDSf did not improve mortality risk stratification when added to PRISM III but did improve mortality risk stratification when added to the gas exchange components of PRISM III (minimum 12-h PaO₂ and maximum 12-h PCO₂) (p < 0.00001).

CONCLUSIONS

AVDSf is associated with mortality and length of ventilation in survivors throughout the first week of invasive mechanical ventilation. Some analyses suggest AVDSf may better stratify mortality risk than OI, whereas OI may better stratify risk for prolonged ventilation in survivors than AVDSf.

Enhancing mechanical and photocatalytic properties by surface microstructure regulation of TiO2 nanofiber membranes

In this work, TiO₂ nanofiber membrane (NFM) with a complete surface microstructure was prepared through regulating the surface microstructure of TiO₂ NFM by doping Zr. The crystal structures and morphological analyses indicated that the nanofiber membranes were consisted by disordered accumulation of Zr-doped TiO₂ nanofibers with a crack-free surface, small grain size and high aspect ratio. When the doping amount of Zr was 0.8 mL, the tensile strength of the doped membranes reached 1.27 MPa, which was 60.7% higher than that of pure TiO₂ NFM. The photocatalytic performance of Zr-doped TiO₂ NFM was evaluated by the degradation performance of Methylene orange (MO) under simulated sunlight irradiation. Compared with the undoped TiO₂ NFM, the 0.8-Zr/TiO₂ NFM presented a higher catalytic degradation efficiency (improved by 69.6%), and the photocatalytic performance maintained stable after five circulating. It was found that the doping of Zr ions effectively limited the surface crack size and grain size of TiO₂ nanofibers, thereby improving the tensile strength, and enhanced the surface area effect and carrier transfer efficiency of TiO₂ NFM. On the other hand, a narrow band-gap was obtained by doping a small amount of Zr ions, which expanded the visible light response range to improve the photocatalytic performance of TiO₂ nanofibers.

Investigation of the flocculating activity of oyster shell powders on Microcystis aeruginosa with varying particle size and mechanical conditions

Harmful algal blooms have been a serious environmental problem. The flocculation of Microcystis aeruginosa by oyster shell powders prepared by aerobic calcination (CO), anaerobic calcination (CN), acidification anaerobic calcination (CAN), and deacetylation anaerobic calcination (CHN) was studied. The CO800 (100 mesh) and CN800 (160 mesh) presented the highest flocculation rate of 89.46% and 77.39% when they were stirred for 1 min with speed of 750 r/min and 250 r/min, respectively. The photosynthesis and viability of the algae cells flocculated by CO800 with particle size of 100 mesh were not significantly damaged. The phosphorus nutrient could be removed by CO800 and CN800 effectively due to the presence of Ca²⁺, which also limited Microcystis aeruginosa growth. The study showed that the processing of oyster shell powder could be used as an effective flocculating material.

A comprehensive correlated analysis of Ra-Doped (ZnO2, ZnO) for optoelectronic applications: a first-principle study

CONTEXT

Zinc oxide (ZnO) exhibits bulk-like behavior and is modified by radium doping to attain favorable electronic properties. The elastic and mechanical response of ZnO₂ is much more favorable than ZnO material. The change in thermal expansion, Debye temperature, free energy, entropy, and specific heat leads it to be a good candidate for thermodynamic applications at low and high temperatures. Optical properties like dielectric function, absorption, refraction, reflection, and refractive index obtained after suitable doping transform the material as optically active. ZnO₂ has low reflectivity and zero absorption below the electronic band gap as compared to ZnO in a wider spectral range. Our analyses on doped ZnO₂ and ZnO make us confident for a wide range of applications in optoelectronic and anti-bacterial treatment in biomedical devices. Especially due to high flexibility and high light transmission, ZnO₂ is an excellent applicant for transparent electrodes.

METHODS

Density functional theory has been employed in consistency with generalized gradient approximation (GGA) with PBEsol to analyze the structural, electronic, elastic, mechanical, thermodynamic, and optical response of pure and Ra-doped (ZnO₂ and ZnO) materials.

Kinematic alignment results in clinically similar outcomes to mechanical alignment: Systematic review and meta-analysis

PURPOSE

It is unclear whether a difference in functional outcome exists between kinematically aligned (KA) and mechanically aligned (MA) knee replacements. The aim of this study is to perform a comprehensive systematic review and meta-analysis of the available level I-IV evidence.

METHODS

A meta-analysis of randomised controlled trials and observational studies comparing patient reported outcome measures (PROMs), range of motion (ROM), gait analysis and complications in TKA with KA and MA was performed. Quality assessment was performed for each study using the Joanna Briggs Institute (JBI) critical appraisal tools.

RESULTS

Twelve randomised controlled trials and fourteen observational studies published between 2014 and 2022 were included in the final analysis. Meta-analysis revealed KA to have significantly better Oxford Knee Score (OKS) (p = 0.02), Forgotten Joint Score (FJS) (p = 0.006), Knee Society Score (KSS) Objective Knee (p = 0.03) and KSS Functional Activity (p = 0.008) scores. However, these improvements did not exceed the minimum clinically important difference (MCID) values reported in the literature. Subgroup analysis showed robotic assisted KA-TKA to have a clinically superior FJS (p = 0.0002) and trend towards KSS Objective Knee score (p = 0.10), compared to PSI. Gait and plantar pressure distribution of KA cohorts more closely represented healthy cohorts, and KA showed a weak association of a decreased knee adduction moment (KAM) compared to MA. Differences in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), range of motion and complications were not significant between groups.

CONCLUSION

Although KA results in several improved functional outcomes, these do not reach clinical significance. Further standardised large-scale randomised studies are required to improve the quality of evidence. As it stands, it is difficult to recommend one philosophy over the other.

One session of 20 ​N cyclic compression induces chronic knee osteoarthritis in rats: A long-term study

Objective

Mechanical stimulation is a risk factor for knee osteoarthritis. Non-surgical compression has been used to study the effects of mechanical stimulation in vivo. However, the long-term effects of low-force compression on knee joint had not been studied. Therefore, we sought to identify the long-term effects of low-force cyclic compression on the rat knee joint.

Design

In this study, we applied one session cyclic compression with a peak load of 20 ​N for 60 cycles to the rat knee joint in an approximately 140-degree flexion position (Wistar, male, 12 weeks old), followed by 1 year of observation (including data from 1 week, 2 weeks, 4 weeks, 8 weeks, 6 months, and 1 year after compression), and then performed a sub-regional analysis with hematoxylin-eosin, Safranin O and Fast Green, and MMP13 immunohistochemical staining.

Results

We observed osteoarthritis-like cartilage damage, synovial inflammation, and high expression of MMP13 within 1 year after compression. However, these changes progressed slowly, with obvious matrix cracks that did not appear until 1 year after compression. In the regional analysis, we found that low-force compression caused a much slower development of injury at the compression contact site, and no significant structural cartilage damage was observed after 1 year of compression. In contrast, the non-contact site during compression at tibial cartilage in the same joint was the first to show significant structural damage.

Conclusion

This study demonstrates that one session of 20 ​N cyclic compression induces a chronic osteoarthritis-like phenotype in the rat knee in the long term.

The impact of different alignment strategies on bone cuts for neutral knee phenotypes in total knee arthroplasty

PURPOSE

The purpose of this study was to simulate and visualise the influence of the alignment strategy on bone resection in neutral knee phenotypes. It was hypothesised that different amounts of bone resection would be required depending on the alignment strategy chosen. The hypothesis was that by visualising the corresponding bone cuts, it would be possible to assess which of the different alignment strategies required the least change to the soft tissues for the chosen phenotype but still ensured acceptable component alignment and could, therefore, be considered the most ideal alignment strategy.

METHODS

Simulations of the different alignment strategies (mechanical, anatomical, restricted kinematic and unrestricted kinematic) regarding their bone resections were performed on four common exemplary neutral knee phenotypes. NEU_HKA0° VAR_FMA 90° VAL_TMA90°, NEU_HKA0° NEU_FMA 93° NEU_TMA87°, NEU_HKA0° VAL_FMA 96° NEU_TMA87° and NEU_HKA0° VAL_FMA 99° VAR_TMA84°. The phenotype system used categorises knees based on overall limb alignment (i.e. hip knee angle) but also considers joint line obliquity (i.e. TKA and FMA) and has been used globally since its introduction in 2019. These simulations are based on long leg weightbearing radiographs. It is assumed that a change of 1° in the alignment of the joint line corresponds to correspond to 1 mm of distal condyle offset.

RESULTS

In the most common neutral phenotype NEU_HKA0° NEU_FMA 93° NEU_TMA87°, with a prevalence of 30%, bone cuts remain below 4 mm regardless of alignment strategy. The greatest changes in the obliquity of the joint line can be expected for the mechanical alignment of the phenotype NEU_HKA0° VAL_FMA 99° VAR_TMA84° where the medial tibia is raised by 6 mm and the lateral femur is shifted distally by 9 mm. In contrast, the NEU_HKA0° VAR_FMA 90° VAL_TMA90° phenotype requires no change in joint line obliquity if the mechanical alignment strategy is used.

CONCLUSION

Illustrations of alignment strategies help the treating surgeon to estimate the postoperative joint line obliquity. When considering the alignment strategy, it seems reasonable to prefer a strategy where the joint line obliquity is changed as little as possible. Although for the most common neutral knee phenotype the choice of alignment strategy seems to be of negligible importance, in general, even for neutral phenotypes, large differences in bone cuts can be observed depending on the choice of alignment strategy.

Mechanical Thrombectomy for M2 Segment Occlusion in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

The safety and benefit of mechanical thrombectomy (MT) in the treatment of acute ischemic stroke (AIS) patients with M2 segment middle cerebral artery occlusions remain uncertain.

OBJECTIVE

To investigate the benefit of mechanical thrombectomy for M2 occlusion compared with M1 occlusion in patients with AIS.

METHODS

The PubMed, Embase, and Cochrane Library databases were searched from inception to April 2021 to identify relevant articles. The main results comprised 90-day functional independence (modified Rankin Score from 0-2), successful recanalization (thrombectomy in cerebral infarction [TICI] 2b/3), mortality, and rates of symptomatic intracerebral hemorrhage after using modern thrombectomy devices. Odds ratios (ORs) were generated for binary variants. ReviewManager 5.3 software was used.

RESULTS

Ultimately, a total of 14 trials were included, with 3454 participants enrolled. MT for M2 occlusion had a higher rate of 3-month functional independence than M1 occlusion, but the difference was nonsignificant (OR: 1.19, 95% confidence interval [CI]: 0.98 to 1.46). The TICI2b/3 scores (OR: 0.71, 95% CI: 0.58-0.88) in M2 occlusion were remarkably lower than those in M1. The mortality and symptomatic intracerebral hemorrhage rates were comparable between the 2 groups. When comparing M2 and M1 occlusions, we found that there was no significant difference between stent retriever and aspiration in the modified Rankin Score (0-2) after AIS, but aspiration exerted an eminently higher recanalization rate with regard to TICI2b/3 (OR: 0.77, 95% CI: 0.61-0.96).

CONCLUSIONS

Compared with M1 occlusion, patients with M2 occlusion treated by MT demonstrated similar clinical outcomes in this study. Moreover, there was no difference between stent retriever and aspiration in treating M2 occlusion in terms of functional independence at 90 days. However, aspiration exerted a conspicuously higher recanalization rate in M2 occlusion than in M1 occlusion.

Experimental characterisation and modelling of breast Cooper's ligaments

The aim of this study was to characterise the mechanical behaviour of Cooper's ligaments. Such ligaments are collagenous breast tissue that create a three-dimensional structure over the entire breast volume. Ten ligaments were extracted from a human cadaver, from which 28 samples were cut and used to perform uniaxial tensile tests. Histological analysis showed that the main direction of the fibres visible to the naked eye corresponds to the orientation of the fibres on a microscopic scale. The specimens were cut according to this orientation, which allowed the sample to be stretched in the main fibre direction. From these experimental stretch/stress curves, an original anisotropic hyperelastic constitutive law is proposed to model the behaviour of Cooper's ligaments and the material parameter validity is discussed.

Exercise to Mend Aged-tissue Crosstalk in Bone Targeting Osteoporosis & Osteoarthritis

Aging induces alterations in bone structure and strength through a multitude of processes, exacerbating common aging- related diseases like osteoporosis and osteoarthritis. Cellular hallmarks of aging are examined, as related to bone and the marrow microenvironment, and ways in which these might contribute to a variety of age-related perturbations in osteoblasts, osteocytes, marrow adipocytes, chondrocytes, osteoclasts, and their respective progenitors. Cellular senescence, stem cell exhaustion, mitochondrial dysfunction, epigenetic and intracellular communication changes are central pathways and recognized as associated and potentially causal in aging. We focus on these in musculoskeletal system and highlight knowledge gaps in the literature regarding cellular and tissue crosstalk in bone, cartilage, and the bone marrow niche. While senolytics have been utilized to target aging pathways, here we propose non-pharmacologic, exercise-based interventions as prospective "senolytics" against aging effects on the skeleton. Increased bone mass and delayed onset or progression of osteoporosis and osteoarthritis are some of the recognized benefits of regular exercise across the lifespan. Further investigation is needed to delineate how cellular indicators of aging manifest in bone and the marrow niche and how altered cellular and tissue crosstalk impact disease progression, as well as consideration of exercise as a therapeutic modality, as a means to enhance discovery of bone-targeted therapies.

Mechanical power in pediatric acute respiratory distress syndrome: a PARDIE study

BACKGROUND

Mechanical power is a composite variable for energy transmitted to the respiratory system over time that may better capture risk for ventilator-induced lung injury than individual ventilator management components. We sought to evaluate if mechanical ventilation management with a high mechanical power is associated with fewer ventilator-free days (VFD) in children with pediatric acute respiratory distress syndrome (PARDS).

METHODS

Retrospective analysis of a prospective observational international cohort study.

RESULTS

There were 306 children from 55 pediatric intensive care units included. High mechanical power was associated with younger age, higher oxygenation index, a comorbid condition of bronchopulmonary dysplasia, higher tidal volume, higher delta pressure (peak inspiratory pressure-positive end-expiratory pressure), and higher respiratory rate. Higher mechanical power was associated with fewer 28-day VFD after controlling for confounding variables (per 0.1 J·min-1·Kg-1 Subdistribution Hazard Ratio (SHR) 0.93 (0.87, 0.98), p = 0.013). Higher mechanical power was not associated with higher intensive care unit mortality in multivariable analysis in the entire cohort (per 0.1 J·min-1·Kg-1 OR 1.12 [0.94, 1.32], p = 0.20). But was associated with higher mortality when excluding children who died due to neurologic reasons (per 0.1 J·min-1·Kg-1 OR 1.22 [1.01, 1.46], p = 0.036). In subgroup analyses by age, the association between higher mechanical power and fewer 28-day VFD remained only in children < 2-years-old (per 0.1 J·min-1·Kg-1 SHR 0.89 (0.82, 0.96), p = 0.005). Younger children were managed with lower tidal volume, higher delta pressure, higher respiratory rate, lower positive end-expiratory pressure, and higher PCO2 than older children. No individual ventilator management component mediated the effect of mechanical power on 28-day VFD.

CONCLUSIONS

Higher mechanical power is associated with fewer 28-day VFDs in children with PARDS. This association is strongest in children < 2-years-old in whom there are notable differences in mechanical ventilation management. While further validation is needed, these data highlight that ventilator management is associated with outcome in children with PARDS, and there may be subgroups of children with higher potential benefit from strategies to improve lung-protective ventilation.

TAKE HOME MESSAGE

Higher mechanical power is associated with fewer 28-day ventilator-free days in children with pediatric acute respiratory distress syndrome. This association is strongest in children <2-years-old in whom there are notable differences in mechanical ventilation management.