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Porous metals are extensively used in load-bearing implants to improve osseointegration. Different processing approaches for porous metals are discussed here. Static and dynamic mechanical properties are critically reviewed for porous metal implants. In vitro and in vivo biological properties of porous metal implants are critically reviewed. Current challenges and future directions for porous metal implants are discussed. Porous and functionally graded materials have seen extensive applications in modern biomedical devices—allowing for improved site-specific performance; their appreciable mechanical, corrosive, and biocompatible properties are highly sought after for lightweight and high-strength load-bearing orthopedic and dental implants. Examples of such porous materials are metals, ceramics, and polymers. Although, easy to manufacture and lightweight, porous polymers do not inherently exhibit the required mechanical strength for hard tissue repair or replacement. Alternatively, porous ceramics are brittle and do not possess the required fatigue resistance. On the other hand, porous biocompatible metals have shown tailorable strength, fatigue resistance, and toughness. Thereby, a significant interest in investigating the manufacturing challenges of porous metals has taken place in recent years. Past research has shown that once the advantages of porous metallic structures in the orthopedic implant industry have been realized, their biological and biomechanical compatibility—with the host bone—has been followed up with extensive methodical research. Various manufacturing methods for porous or functionally graded metals are discussed and compared in this review, specifically, how the manufacturing process influences microstructure, graded composition, porosity, biocompatibility, and mechanical properties. Most of the studies discussed in this review are related to porous structures for bone implant applications; however, the understanding of these investigations may also be extended to other devices beyond the biomedical field.

Microquasars are laboratories for the study of jets of relativistic particles produced by accretion onto a spinning black hole. Microquasars are near enough to allow detailed imaging of spatial features across the multiwavelength spectrum. The recent extension measurement of the spatial morphology of a microquasar, SS 433, to TeV gamma rays 1 localizes the acceleration of electrons at shocks in the jet far from the black hole 2 . V4641 Sagittarii (V4641 Sgr) is a similar binary system with a black hole and B-type main-sequence companion star and has an orbit period of 2.8 days (refs.  3 , 4 ). It stands out for its super-Eddington accretion 5 and for its radio jet, which is one of the fastest superluminal jets in the Milky Way. Previous observations of V4641 Sgr did not report gamma-ray emission 6 . Here we report TeV gamma-ray emission from V4641 Sgr that reveals particle acceleration at similar distances from the black hole as SS 433. Furthermore, the gamma-ray spectrum of V4641 Sgr is among the hardest TeV spectra observed from any known gamma-ray source and is detected above 200 TeV. Gamma rays are produced by particles, either electrons or protons, of higher energies. Because energetic electrons lose energy more quickly the higher their energy, such a spectrum either very strongly constrains the electron-production mechanism or points to the acceleration of high-energy protons. This suggests that large-scale jets from microquasars could be more common than previously expected and that they could be a notable source of galactic cosmic rays 7 – 9 . Ultra-high-energy gamma-ray emission from the microquasar V4641 Sagittarii is reported, suggesting that large-scale jets from microquasars could be more common than previously thought and also could be a notable source of galactic cosmic rays.

Background Vaginal dysbiosis is considered a risk factor for the development of gynecological and obstetric complications. This study aimed to evaluate the effects of vaginal gel containing lactic acid on vaginal pH, microbiota composition, and Candida species in asymptomatic women of reproductive age. Methods: 55 menstruating women, with no gynecological complaints, participated in the study, using a gel containing lactic acid twice a week, for 8 weeks. Assessments were conducted before and after the intervention, including measurements of vaginal pH, Nugent score, vaginal microbiota characteristics (alpha diversity index and Community State Types [CSTs] classification), and identification of Candida species. Results: At baseline, 36.4% of women exhibited CST type IV vaginal microbiota, followed by CST type III (30.9%), with vaginal pH values ranging from 4 to 5. After the intervention, there was a significant reduction in vaginal pH (p = 0.0057) and Nugent scores (p = 0.0047). Furthermore, a statistically significant decline was observed in the prevalence of unfavorable taxonomic groups, including Prevotella amnii and Bacterial Vaginosis Associated Bacterium 1, while vaginal lactobacilli remained unaffected. Despite these positive changes, the intervention did not result in a statistically significant alteration in microbial diversity or CST composition (p = 0.12). The gel was well-tolerated, with a low incidence of mild adverse effects reported. Conclusions: The lactic acid-containing gel demonstrated a significant reduction in vaginal pH and Nugent scores in asymptomatic women, indicating possible improvement in vaginal health, that needs to be confirmed in a placebo-controlled study. Although the intervention did not influence microbial diversity and the type of vaginal microbiota at the end of the study, it was able to reduce the prevalence of some taxonomic groups after intervention with the vaginal gel.

Ti3Al2V demonstrated comparable mechanical performance to Ti6Al4V. Adding 3 wt.% Cu in Ti3Al2V reduced planktonic bacteria colonies by 78%–86% compared to commercially pure Ti. Ti3Al2V–10Ta displayed the best in vivo biocompatibility with 3.5-fold higher bone formation than Ti6Al4V. Ti3Al2V–10Ta–3Cu multifaceted alloy has the potential to replace Ti6Al4V in orthopedic and dental applications with superior early-stage osseointegration and inherent antibacterial performance. Bacterial colonization of orthopedic implants is one of the leading causes of failure and clinical complexities for load-bearing metallic implants. Topical or systemic administration of antibiotics may not offer the most efficient defense against colonization, especially in the case of secondary infection, leading to surgical removal of implants and in some cases even limbs. In this study, laser powder bed fusion was implemented to fabricate Ti3Al2V alloy by a 1:1 weight mixture of CpTi and Ti6Al4V powders. Ti-Tantalum (Ta)–Copper (Cu) alloys were further analyzed by the addition of Ta and Cu into the Ti3Al2V custom alloy. The biological, mechanical, and tribo-biocorrosion properties of Ti3Al2V alloy were evaluated. A 10 wt.% Ta (10Ta) and 3 wt.% Cu (3Cu) were added to the Ti3Al2V alloy to enhance biocompatibility and impart inherent bacterial resistance. Additively manufactured implants were investigated for resistance against Pseudomonas aeruginosa and Staphylococcus aureus strains of bacteria for up to 48 h. A 3 wt.% Cu addition to Ti3Al2V displayed improved antibacterial efficacy, i.e. 78%–86% with respect to CpTi. Mechanical properties for Ti3Al2V–10Ta–3Cu alloy were evaluated, demonstrating excellent fatigue resistance, exceptional shear strength, and improved tribological and tribo-biocorrosion characteristics when compared to Ti6Al4V. In vivo studies using a rat distal femur model revealed improved early-stage osseointegration for alloys with 10 wt.% Ta addition compared to CpTi and Ti6Al4V. The 3 wt.% Cu-added compositions displayed biocompatibility and no adverse inflammatory response in vivo . Our results establish the Ti3Al2V–10Ta–3Cu alloy’s synergistic effect on improving both in vivo biocompatibility and microbial resistance for the next generation of load-bearing metallic implants.

This work presents an experimental study on the influence of the pilot flame characteristics on the flame morphology and exhaust emissions of a turbulent swirling flame. A reduced-scale burner, inspired by that fitted in the AE-T100 micro gas turbine, was employed as the experimental platform to evaluate methane (CH4) and an ammonia-methane fuel blend with an ammonia (NH3) volume fraction of 0.7. The power ratio (PR) between the pilot flame and the main flame and the fuel composition of the pilot flame was investigated. The pilot power ratio was varied from 0 to 20% for both fuel compositions tested. The NH3 volume fraction in the pilot flame ranged from pure CH4 to pure NH3 through various NH3–CH4 blends. Flame images and exhaust emissions, namely CO2, CO, NO, and N2O were recorded. It was found that increasing the pilot power ratio produces more stable flames and influences most of the exhaust emissions measured. The CO2 concentration in the exhaust gases was roughly constant for CH4-air or NH3–CH4–air flames. In addition, a CO2 concentration reduction of about 45% was achieved for XNH3 = 0.70 compared with pure CH4, while still producing stable flames as long as PR ≥ 5%. The pilot power ratio was found to have a higher relative impact on NO emissions for CH4 than for NH3–CH4, with measured exhaust NO percentage increments of about 276% and 11%, respectively. The N2O concentration was constant for all pilot power ratios for CH4 but it decreased when the pilot power ratio increased for NH3–CH4. The pilot fuel composition highly affected the NO and N2O emissions. Pure CH4 pilot flames and higher power ratios produced higher NO emissions. Conversely, the NO concentration was roughly constant for pure NH3 pilot flames, regardless of the pilot power ratio. Qualitative OH-PLIF images were recorded to further investigate these trends. Results showed that the pilot power ratio and the pilot fuel composition modified the flame morphology and the OH concentration, which both influence NO emissions.

SS 433 is a binary system containing a supergiant star that is overflowing its Roche lobe with matter accreting onto a compact object (either a black hole or neutron star) 1 – 3 . Two jets of ionized matter with a bulk velocity of approximately 0.26 c (where c is the speed of light in vacuum) extend from the binary, perpendicular to the line of sight, and terminate inside W50, a supernova remnant that is being distorted by the jets 2 , 4 – 8 . SS 433 differs from other microquasars (small-scale versions of quasars that are present within our own Galaxy) in that the accretion is believed to be super-Eddington 9 – 11 , and the luminosity of the system is about 10 40 ergs per second 2 , 9 , 12 , 13 . The lobes of W50 in which the jets terminate, about 40 parsecs from the central source, are expected to accelerate charged particles, and indeed radio and X-ray emission consistent with electron synchrotron emission in a magnetic field have been observed 14 – 16 . At higher energies (greater than 100 gigaelectronvolts), the particle fluxes of γ -rays from X-ray hotspots around SS 433 have been reported as flux upper limits 6 , 17 – 20 . In this energy regime, it has been unclear whether the emission is dominated by electrons that are interacting with photons from the cosmic microwave background through inverse-Compton scattering or by protons that are interacting with the ambient gas. Here we report teraelectronvolt γ-ray observations of the SS 433/W50 system that spatially resolve the lobes. The teraelectronvolt emission is localized to structures in the lobes, far from the centre of the system where the jets are formed. We have measured photon energies of at least 25 teraelectronvolts, and these are certainly not Doppler-boosted, because of the viewing geometry. We conclude that the emission—from radio to teraelectronvolt energies—is consistent with a single population of electrons with energies extending to at least hundreds of teraelectronvolts in a magnetic field of about 16 microgauss. Observations of teraelectronvolt γ-rays accelerated by the jets of the miniature quasar SS 433 are reported.

In this study, leaves, and stem extracts of the Bougainvillea spectabilis (BS) plant were used separately as reducing and stabilizing agents to obtain silver nanoparticles (AgNPs). The UV-Vis characterizations show different positions to the absorption band associated with surface plasmon resonance (SPR) in AgNPs. The absorption bands centered at 372 and 435 nm were observed with the stem and leaves extract, respectively. In both cases, these behaviors were associated with SPR in AgNPs. TEM (transmission electron microscopy) micrographs reveal relatively spherical morphologies, with particle diameters around 11 nm with a hexagonal phase. AgNPs were evaluated as SERS (surface enhanced Raman spectroscopy) substrates detecting pyridoxine at low concentrations. The theoretical results indicate a possible charge transfer between the two systems and susceptibility to Raman activity enhancement on the radial breathing mode type of the pyridinic ring located at approximately 690 cm−1.

Regular physical activity (PA) is an important part of the treatment of several medical conditions, including overweight and obesity, in which there may be a weakened appetite control. Eating behaviour traits influence weight control and may be different in active and sedentary subjects. This paper reports the relationships between the time spent in sedentary behaviour and physical activity (PA) of different intensity, and eating behaviour traits in young, healthy adults. Additionally, it reports the results of a six-month-long, randomized, controlled trial to examine the effect of an exercise intervention on eating behaviour traits. A total of 139 young (22.06 ± 2.26 years) healthy adults (68.35% women) with a Body Mass Index (BMI) of 24.95 ± 4.57 kg/m2 were enrolled. Baseline assessments of habitual PA were made using wrist-worn triaxial accelerometers; eating behaviour traits were examined via the self-reported questionnaires: Binge Eating, Three-Factor Eating Questionnaire-R18 and Control of Eating Questionnaire. The subjects were then randomly assigned to one of three groups: control (usual lifestyle), moderate-intensity exercise (aerobic and resistance training 3¨C4 days/week at a heart rate equivalent to 60% of the heart rate reserve (HRres) for the aerobic component, and at 50% of the 1 repetition maximum (RM) for the resistance component), or vigorous-intensity exercise (the same training but at 80% HRres for half of the aerobic training, and 70% RM for the resistance training). At baseline, sedentary behaviour was inversely associated with binge eating (r = −0.181, p < 0.05) and with uncontrolled eating (r = −0.286, p = 0.001). Moderate PA (MPA) was inversely associated with craving control (r = −0.188, p < 0.05). Moderate-to-vigorous PA (MVPA) was directly associated with binge eating (r = 0.302, p < 0.001) and uncontrolled eating (r = 0.346, p < 0.001), and inversely associated with craving control (r = −0.170, p < 0.015). Overall, PA was directly associated with binge eating (r = 0.275, p = 0.001), uncontrolled eating (r = 0.321, p < 0.001) and emotional eating (r = 0.204, p < 0.05). Additionally, only emotional eating was modified by the intervention, increasing in the vigorous-intensity exercise group (p < 0.05). In summary, we observed that time spent in sedentary behaviour/PA of different intensity is associated with eating behaviour traits, especially binge eating in young adults. In contrast, the six-month exercise intervention did not lead to appreciable changes in eating behaviour traits.

Chronic graft-versus-host disease (cGVHD) remains a major cause of non-relapse morbidity and mortality after allogeneic hematopoietic stem cell transplantation. Currently there are no accepted measures of cGVHD activity to aid in clinical management and disease staging. We analyzed clinical markers of inflammation in the sera of patients with established cGVHD and correlated those with definitions of disease activity. In all, 189 adults with cGVHD (33% moderate and 66% severe according to National Institutes of Health (NIH) global scoring) were consecutively enrolled onto a cross-sectional prospective cGVHD natural history study. At the time of evaluation, 80% were receiving systemic immunosuppression and failed a median of four prior systemic therapies (PST) for their cGVHD. Lower albumin ( P <0.0001), higher C-reactive protein ( P =0.043), higher platelets ( P =0.030) and higher number of PST ( P <0.0001) were associated with active disease defined as clinician's intention to intensify or alter systemic therapy due to the lack of response. Higher platelet count ( P =0.021) and higher number of PST ( P <0.0001) were associated with more severe diseased defined by NIH global score. This study identified common laboratory indicators of inflammation that can serve as markers of cGVHD activity and severity.