A lanthanide-rich kilonova in the aftermath of a long gamma-ray burst.

Observationally, kilonovae are astrophysical transients powered by the radioactive decay of nuclei heavier than iron, thought to be synthesized in the merger of two compact objects1-4. Over the first few days, the kilonova evolution is dominated by a large number of radioactive isotopes contributing to the heating rate2,5. On timescales of weeks to months, its behaviour is predicted to differ depending on the ejecta composition and the merger remnant6-8. Previous work has shown that the kilonova associated with gamma-ray burst 230307A is similar to kilonova AT2017gfo (ref. 9), and mid-infrared spectra revealed an emission line at 2.15 micrometres that was attributed to tellurium. Here we report a multi-wavelength analysis, including publicly available James Webb Space Telescope data9 and our own Hubble Space Telescope data, for the same gamma-ray burst. We model its evolution up to two months after the burst and show that, at these late times, the recession of the photospheric radius and the rapidly decaying bolometric luminosity (Lbol ∝ t-2.7±0.4, where t is time) support the recombination of lanthanide-rich ejecta as they cool.

Extraction of functional natural products employing microwave-assisted aqueous two-phase system: application to anthocyanins extraction from mulberry fruits.

Aqueous two-phase extraction (ATPE) has been extensively utilized for the extraction and separation of tiny-molecule substances as a new system (system with short-chain ethanol and inorganic salts). In this study, an innovative method of extracting anthocyanins from mulberry was developed, employing microwave-assisted extraction with ethanol/ammonium sulfate as a biphasic extractant. Response surface methodology (RSM) was utilized to optimize anthocyanin extraction conditions: 39% ethanol (w/w), 13% ammonium sulfate (w/w), and liquid-to-solid ratio of 45:1, microwave duration 3 min, microwave temperature 32 °C, and microwave power 480 Watt (W). High-performance liquid chromatography (HPLC) analysis demonstrated no significant differences in the structure of mulberry anthocyanins before and after MAATPE treatment, furthermore. The extraction behavior of MAATPE was due to hydrogen bonding, according to Fourier transform infrared spectroscopy (FT-IR). Scanning electron microscopy analysis found that MAATPE damaged the cell structure via a microwave enhancement effect, which was more favorable to anthocyanin dissolution than standard extraction methods. The DPPH free radical scavenging rate of mulberry extracts at 0.5 mg/mL was higher than that of vitamin C (96.4 ± 0.76%), and the ABTS free radical scavenging rate (82.52 ± 2.13%) was close to that of vitamin C, indicating that MAATPE-derived mulberry extracts have good antioxidant activity.

Steric-hindrance Effect Tuned Ion Solvation Enabling High Performance Aqueous Zinc Ion Batteries.

Despite many additives have been reported for aqueous zinc ion batteries, steric-hindrance effect of additives and its correlation with Zn2+ solvation structure have been rarely reported. Herein, large-sized sucrose biomolecule is selected as a paradigm additive, and steric-hindrance electrolytes (STEs) are developed to investigate the steric-hindrance effect for solvation structure regulation. Sucrose molecules do not participate in Zn2+ solvation shell, but significantly homogenize the distribution of solvated Zn2+ and enlarge Zn2+ solvation shell with weakened Zn2+-H2O interaction due to the steric-hindrance effect. More importantly, STEs afford the water-shielding electric double layer and in situ construct the organic and inorganic hybrid solid electrolyte interface, which effectively boost Zn anode reversibility. Remarkably, Zn//NVO battery presents high capacity of 3.9 mAh ⋅ cm-2 with long cycling stability for over 650 cycles at lean electrolyte of 4.5 µL ⋅ mg-1 and low N/P ratio of 1.5, and the stable operation at wide temperature (-20 °C~+40 °C).

Ternary Lithium Nickel Boride with 1D Rapid-Ion-Diffusion Channels as an Anode for Use in Lithium-Ion Batteries.

Anode materials with high-rate performances and good electrochemical stabilities are urgently required for the grid-scale application of lithium-ion batteries (LIBs). Theoretically, transition metal borides are desirable candidates because of their appropriate working potentials and good conductivities. However, the reported metal borides exhibit poor performances owing to their lack of favorable Li+ storage sites and poor structural stabilities during long-term charging/discharging. In this work, a ternary alkali metal boride, Li1.2 Ni2.5 B2 , which displays a high Li+ storage capacity and remarkable electrochemical stability and an excellent rate performance is studied. In contrast to conventional transition metal borides, the introduction of Li atoms facilitates the formation of 1D Ni/B-based honeycomb channels during synthesis. This Ni/B framework successfully sustains the strain during Li+ intercalation and deintercalation, and thus, the optimized Li1.2 Ni2.5 B2 anode exhibits an excellent cycle stability over 500 charge/discharge cycles. This electrode also exhibits superior reversible capacities of 350, 183, and 80 mA h g-1 at 0.1, 1, and 5 A g-1 , respectively, indicating the considerable potential of the 1D Ni/B framework as a commercially available fast-charging LIB anode.

Quickly assessing disinfection effectiveness to control the spread of African swine fever virus.

Infectious African swine fever virus (ASFV) can cause the spread and morbidity of African swine fever, while the inactivated virus cannot. When they are not distinguished separately, the detection results will lack authenticity and cause unnecessary panic and detection cost. The detection technology based on cell culture is complex, high-cost, and time-consuming in practice, which is not conducive to the rapid detection of infectious ASFV. In this study, a propidium monoazide (PMA) qPCR detection method for rapid diagnosis of infectious ASFV was constructed. Parameters of PMA concentration, light intensity, and lighting time were under strict safety verification and comparative analysis for optimization. The results determined that the optimal condition for PMA to pretreat ASFV was the final concentration of PMA 100 µM. The light intensity was 40 W, the light duration was 20 min, the target fragment size of the optimal primer probe was 484 bp, and its detection sensitivity for infectious ASFV was 101.28 HAD50/mL. In addition, the method was innovatively applied to the rapid evaluation of disinfection effect. When ASFV concentration was less than 102.28 HAD50/mL, the method could still be effective for the evaluation of thermal inactivation effect, and the evaluation ability of chlorine-containing disinfectants was better, and the applicable concentration could reach 105.28 HAD50/mL. It is worth mentioning that this method can not only reflect whether the virus is inactivated, but also indirectly reflect the degree of damage to viral nucleic acid caused by disinfectants. In conclusion, the PMA-qPCR constructed in this study can be applied to laboratory diagnosis, disinfection effect evaluation, drug development, and other aspects of infectious ASFV and can provide new technical support for effective prevention and control of ASF. KEY POINTS: • A rapid detection method for infectious ASFV was developed • Provide a new scheme for rapid evaluation of disinfection effect of chlorine-containing disinfectants • PMA-qPCR can simultaneously show the survival status of the virus and the damage of nucleic acid.

Optimal control analysis of a multigroup SEAIHRD model for COVID-19 epidemic.

The COVID-19 pandemic has threatened public health and caused substantial economic loss to most countries worldwide. A multigroup susceptible-exposed-asymptomatic-infectious-hospitalized-recovered-dead (SEAIHRD) compartment model is first constructed to model the spread of the disease by dividing the population into three age groups: young (aged 0-19), prime (aged 20-64), and elderly (aged 65 and over). Then, we develop a free terminal time, partially fixed terminal state optimal control problem to minimize deaths and costs associated with hospitalization and the implementation of different control strategies. And the optimal strategies are derived under different assumptions about medical resources and vaccination. Specifically, we explore optimal control strategies for reaching herd immunity in the COVID-19 outbreak in a free terminal time situation to evaluate the effect of nonpharmaceutical interventions (NPIs) and vaccination as control measures. The transmission rate of SARS-CoV-2 is calibrated by using real data in the United States at the early stage of the epidemic. Through numerical simulation, we conclude that the outbreak of COVID-19 can be contained by implementing appropriate control of the prime age population and relatively strict control measures for young and elderly populations. Within a specific period, strict control measures should be implemented before the vaccine is marketed.

Novel economical, accurate, sensitive, single-cell analytical method for mitochondrial DNA quantification in mtDNA mutation carriers.

PURPOSE: Although a variety of analytical methods have been developed to detect mitochondrial DNA (mtDNA) heteroplasmy, there are special requirements of mtDNA heteroplasmy quantification for women carrying mtDNA mutations receiving the preimplantation genetic diagnosis (PGD) and prenatal diagnosis (PD) in clinic. These special requirements include various sample types, large sample number, long-term follow-up, and the need for detection of single-cell from biopsied embryos. Therefore, developing an economical, accurate, high-sensitive, and single-cell analytical method for mtDNA heteroplasmy is necessary. METHODS: In this study, we developed the Sanger sequencing combined droplet digital polymerase chain reaction (ddPCR) method for mtDNA quantification and compared the results to next-generation sequencing (NGS). A total of seventeen families with twelve mtDNA mutations were recruited in this study. RESULTS: The results showed that both Sanger sequencing and ddPCR could be used to analyze the mtDNA heteroplasmy in single-cell samples. There was no statistically significant difference in heteroplasmy levels in common samples with high heteroplasmy (≥ 5%), low heteroplasmy (< 5%), and single-cell samples, either between Sanger sequencing and NGS methods, or between ddPCR and NGS methods (P > 0.05). However, Sanger sequencing was unable to detect extremely low heteroplasmy accurately. But even in samples with extremely low heteroplasmy (0.40% and 0.92%), ddPCR was always able to quantify them. Compared to NGS, Sanger sequencing combined ddPCR analytical methods greatly reduced the cost of sequencing. CONCLUSIONS: In conclusion, this study successfully established an economical, accurate, sensitive, single-cell analytical method based on the Sanger sequencing combined ddPCR methods for mtDNA heteroplasmy quantification in a clinical setting.

Polymorphisms of mtDNA in the D-loop region moderate the associations of BMI with HOMA-IR and HOMA-ß among women with polycystic ovary syndrome: a cross-sectional study.

PURPOSE: Polycystic ovary syndrome (PCOS) is one of the leading causes of infertility in women of childbearing age, and many patients with PCOS have obesity and insulin resistance (IR). Although obesity is related to an increased risk of IR, in clinical practice, PCOS patients exhibit different effects on improving insulin sensitivity after weight loss. Therefore, in the present study, we aimed to examine the moderating effect of polymorphisms of mtDNA in the D-loop region on the associations of body mass index (BMI) with the homeostasis model assessment of insulin resistance index (HOMA-IR) and pancreatic ß cell function index (HOMA-ß) among women with PCOS. METHODS: Based on a cross-sectional study, women with PCOS were recruited from the Reproductive Center of the First Affiliated Hospital of Anhui Medical University from 2015 to 2018. A total of 520 women who were diagnosed with PCOS based on the revised 2003 Rotterdam criteria were included in the study. Peripheral blood was collected from these patients, followed by DNA extraction, PCR amplification, and sequencing at baseline. HOMA-IR and HOMA-ß were calculated according to blood glucose-related indices. Moderating effect models were performed with BMI as an independent variable, polymorphisms of mtDNA in the D-loop region as moderators, and ln (HOMA-IR) and ln (HOMA-ß) as dependent variables. To verify the stability of moderating effect, sensitivity analysis was performed with the quantitative insulin sensitivity check index (QUICKI), fasting plasma glucose/fasting insulin (G/I), and fasting insulin as dependent variables. RESULTS: BMI was positively associated with ln (HOMA-IR) and ln (HOMA-ß) (ß = 0.090, p < 0.001; ß = 0.059, p < 0.001, respectively), and the relationship between BMI and ln (HOMA-IR) or ln (HOMA-ß) was moderated by the polymorphisms of mtDNA in the D-loop region. Compared with the respective wild-type, the variant -type of m.16217 T > C enhanced the association between BMI and HOMA-IR, while the variant-type of m.16316 A > G weakened the association. On the other hand, the variant-type of m.16316 A > G and m.16203 A > G weakened the association between BMI and HOMA-ß, respectively. The results of QUICKI and fasting insulin as dependent variables were generally consistent with HOMA-IR, and the results of G/I as dependent variables were generally consistent with HOMA-ß. CONCLUSION: Polymorphisms of mtDNA in the D-loop region moderate the associations of BMI with HOMA-IR and HOMA-ß among women with PCOS.

Bridging 1D Inorganic and Organic Synthesis to Fabricate Ultrathin Bismuth-Based Nanotubes with Controllable Size as Anode Materials for Secondary Li Batteries.

The growth of ultrathin 1D inorganic nanomaterials with controlled diameters remains challenging by current synthetic approaches. A polymer chain templated method is developed to synthesize ultrathin Bi2 O2 CO3 nanotubes. This formation of nanotubes is a consequence of registry between the electrostatic absorption of functional groups on polymer template and the growth habit of Bi2 O2 CO3 . The bulk bismuth precursor is broken into nanoparticles and anchored onto the polymer chain periodically. These nanoparticles react with the functional groups and gradually evolve into Bi2 O2 CO3 nanotubes along the chain. 5.0 and 3.0 nm tubes with narrow diameter deviation are synthesized by using branched polyethyleneimine and polyvinylpyrrolidone as the templates, respectively. Such Bi2 O2 CO3 nanotubes show a decent lithium-ion storage capacity of around 600 mA h g-1 at 0.1 A g-1 after 500 cycles, higher than other reported bismuth oxide anode materials. More interestingly, the Bi materials developed herein still show decent capacity at very low temperatures, that is, around 330 mA h g-1 (-22 °C) and 170 mA h g-1 (-35 °C) after 75 cycles at 0.1 A g-1 , demonstrating their promising potential for practical application in extreme conditions.

The associations of serum metals concentrations with the intermediate and pregnancy outcomes in women undergoing in vitro fertilization (IVF).

BACKGROUND: Toxic and essential trace elements are reported to have impact on female fertility. However, studies on the potential synergistic or antagonistic effects of metal mixtures on IVF outcomes remain limited. OBJECTIVE: To evaluate whether serum concentrations of metals, individually and as mixtures, are associated with pregnancy outcomes in women undergoing IVF. METHODS: In a prospective birth cohort study about IVF from the First Affiliated Hospital of Anhui Medical University (n = 1184), we measured the concentrations of serum metals by ICP-MS according to a previously established method. Oocyte/embryo development indicators and follow-up results were also collected. The individual and joint effects of metals were estimated using logistic regressions and Bayesian kernel machine regressions (BKMR). RESULTS: At embryonic stage, we found negative associations between the serum lead (Pb) (ß = -0.14, 95%CI: -0.32, -0.04) and cadmium (Cd) (ß = -0.24, 95%CI: -0.39, -0.09) concentrations and the high-quality embryos rate; and positive associations between the serum cobalt (Co) (ß = 0.18, 95%CI: 0.05, 0.31) and selenium (Se) (ß = 0.17, 95%CI: 0.06, 0.41) concentrations and the MII rate. Regarding to the pregnancy outcomes, the serum Pb was negatively related with successful implantation (OR=0.85, 95%CI: 0.77, 0.94) and clinical pregnancy (OR=0.95, 95%CI: 0.91, 0.99); and positively associated with spontaneous abortion (OR=1.39, 95% CI: 1.02, 1.91). The BKMR analysis showed linear or parabolic associations between the metal mixtures and pregnancy outcomes, with Pb showing the highest posterior inclusion probabilities. CONCLUSIONS: The toxic (Pb, Cd) and essential (Co, Se) metals could be incorporated as simultaneous predictors of IVF outcomes including potential antagonistic effects, in which Pb exhibits major contributions.

Three-Dimensional Limit of Bulk Rashba Effect in Ferroelectric Semiconductor GeTe.

Ferroelectric Rashba semiconductors (FERSCs) have recently attracted intensive attention due to their giant bulk Rashba parameter, αR, which results in a locking between the spin degrees of freedom and the switchable electric polarization. However, the integration of FERSCs into microelectronic devices has provoked questions concerning whether the Rashba effect can persist when the material thickness is reduced to several nanometers. Here we find that αR can keep a large value of 2.12 eV Å in the 5.0 nm thick GeTe film. The behavior of αR with thickness can be expressed by the scaling law and provides a 3D thickness limit of the bulk Rashba effect, dc = 2.1 ± 0.5 nm. Finally, we find that the thickness can modify the Berry curvature as well, which influences the polarization and consequently alters the αR. Our results give insight into understanding the factors influencing αR in FERSCs and pave a novel route for designing Rashba-type quantum materials.

Orienting and shaping organic semiconductor single crystals through selective nanoconfinement.

For organic semiconductor crystals exhibiting anisotropic charge transport along different crystallographic directions, nanoconfinement is a powerful strategy to control crystal orientation by aligning the fast crystallographic growth direction(s) with the unconfined axis(es) of nanoconfining scaffolds. Here, design rules are presented to relate crystal morphology, scaffold geometry, and orientation control in solution-processed small-molecule crystals. Specifically, organic semiconductor triisopropylsilylethynyl pyranthrene needle-like crystals with a dimensionality of n = 1 and perylene platelike crystals with n = 2 were grown from solution within nanoconfining scaffolds comprising cylindrical nanopores with a dimensionality of m = 1, representing one unconfined dimension along the cylinder axis, and those comprising nanopillar arrays with a dimensionality of m = 2. For m = n systems, native crystal growth habits were preserved while the crystal orientation in n = m direction(s) was dictated by the geometry of the scaffold. For n≠m systems, on the other hand, orientation control was restricted within a single plane, either parallel or perpendicular to the substrate surface. Intriguingly, control over crystal shape was also observed for perylene crystals grown in cylindrical nanopores (n > m). Within the nanopores, crystal growth was restricted along a single direction to form a needle-like morphology. Once growth proceeded above the scaffold surface, the crystals adopted their native growth habit to form asymmetric T-shaped single crystals with concave corners. These findings suggest that nanoporous scaffolds with spatially-varying dimensionalities can be used to grow single crystals of complex shapes.

Preimplantation genetic diagnosis for a carrier with m.3697G > A mitochondrial DNA mutation.

OBJECTIVE: To explore inheritance of the m.3697G > A mitochondrial DNA (mtDNA) mutation and the effectiveness of preimplantation genetic diagnosis (PGD) for the carrier. METHODS: The study encompassed a pedigree of m.3697G > A mtDNA mutation, including one asymptomatic patient who pursued for PGD treatment. Twelve cumulus oocyte complexes (COCs) were collected in the first PGD cycle and 11 COCs in the second cycle. The efficiency of cumulus cells, polar bodies, and trophectoderm (TE) in predicting the m.3697G > A heteroplasmy of embryos was analyzed. RESULTS: From 23 COCs, 20 oocytes were fertilized successfully. On day 5 and 6 post-fertilization, 15 blastocysts were biopsied. The m.3697G > A mutation load of TE biopsies ranged from 15.2 to 100%. In the first cycle, a blastocyst with mutation load of 31.7% and chromosomal mosaicism was transferred, but failed to yield a clinical pregnancy. In the second cycle, a euploid blastocyst with mutation load of 53.9% was transferred, which gave rise to a clinical pregnancy. However, the pregnancy was terminated due to fetal cleft lip and palate. The mutation loads of different tissues (47.7 ± 1.8%) from the induced fetus were comparable to that of the biopsied TE and amniotic fluid cell (49.7%). The mutation load of neither cumulus cells (R2 = 0.02, p = 0.58) nor polar bodies (R2 = 0.33, p = 0.13) correlated with TE mutation load which was regarded as a gold standard. CONCLUSIONS: The m.3697G > A mutation showed a random pattern of inheritance. PGD could be used to reduce the risk of inheritance of a high mutation load. Cumulus cells are not a suitable predictor of blastocyst mutation load.

Diagnostic Performance of Acoustic Radiation Force Impulse Elastography for the Differentiation of Benign and Malignant Superficial Lymph Nodes: A Meta-analysis.

To estimate the diagnostic performance of acoustic radiation force impulse elastography in distinguishing between benign and malignant superficial lymph nodes, relevant articles published before October 31, 2018, in China and other countries were used. Conclusively, a total of 18 articles were analyzed. Sixteen studies used Virtual Touch tissue quantification (Siemens Healthineers, Erlangen, Germany), and 4 studies used Virtual Touch tissue imaging (Siemens Healthineers). After a meta-analysis, it was found that acoustic radiation force impulse elastography is an efficient method for detecting superficial lymph nodes. In addition, if the cutoff value for the shear wave velocity were less than 2.85 m/s, the summary sensitivity would increase, and the heterogeneity would be reduced.

Large Tunable Spin-to-Charge Conversion Induced by Hybrid Rashba and Dirac Surface States in Topological Insulator Heterostructures.

Topological insulators (TIs) have emerged as some of the most efficient spin-to-charge convertors because of their correlated spin-momentum locking at helical Dirac surface states. While endeavors have been made to pursue large "charge-to-spin" conversions in novel TI materials using spin-torque-transfer geometries, the reciprocal process "spin-to-charge" conversion, characterized by the inverse Edelstein effect length (λIEE) in the prototypical TI material (Bi2Se3), remains moderate. Here, we demonstrate that, by incorporating a "second" spin-splitting band, namely, a Rashba interface formed by inserting a bismuth interlayer between the ferromagnet and the Bi2Se3 (i.e., ferromagnet/Bi/Bi2Se3 heterostructure), λIEE shows a pronounced increase (up to 280 pm) compared with that in pure TIs. We found that λIEE alters as a function of bismuth interlayer thickness, suggesting a new degree of freedom to manipulate λIEE by engineering the interplay of Rashba and Dirac surface states. Our finding launches a new route for designing TI- and Rashba-type quantum materials for next-generation spintronic applications.

Undercoordination Chemistry of Sulfur Electrocatalyst in Lithium-Sulfur Batteries.

Undercoordination chemistry is an effective strategy to modulate the geometry-governed electronic structure and thereby regulate the activity of sulfur electrocatalysts. Efficient sulfur electrocatalysis is requisite to overcome the sluggish kinetics in lithium-sulfur (Li-S) batteries aroused by multi-electron transfer and multi-phase conversions. Recent advances unveil the great promise of undercoordination chemistry in facilitating and stabilizing sulfur electrochemistry, yet a related review with systematicness and perspectives is still missing. Herein, it is carefully combed through the recent progress of undercoordination chemistry in sulfur electrocatalysis. The typical material structures and operational strategies are elaborated, while the underlying working mechanism is also detailly introduced and generalized into polysulfide adsorption behaviors, polysulfide conversion kinetics, electron/ion transport, and dynamic reconstruction. Moreover, perspectives on the future development of undercoordination chemistry are further proposed.

Serum Essential Trace Element Status in Women and the Risk of Endometrial Diseases: a Case-Control Study : Serum Essential Trace Element Status in Women and the Risk of Endometrial Diseases: a Case-Control Study.

Endometrial diseases, including uterine fibroids, polyps, intrauterine adhesion, endometritis, etc., are the major causes of infertility among women. However, the association between essential trace element status in women and the risk of endometrial disease is limited and unclear. This study aimed to investigate this association using a case-control study design; a total of 302 women patients with endometrial diseases and 302 healthy women were included. Compared to women in the control group, serum selenium (Se) (p = 0.024) and zinc (Zn) (p = 0.017) levels were significantly lower, while copper (Cu) (p = 0.004) and molybdenum (Mo) (p = 0.005) levels were significantly higher among women with endometrial diseases. In addition, compared to women in the first quartile of the copper/zinc (Cu/Zn) ratio value group, the adjusted ORs (95% CIs) of endometrial diseases were 1.50 (1.05, 2.14), 1.68 (1.18, 2.39), and 1.47 (1.02, 2.10), respectively, in the second, third, and fourth quartile of the Cu/Zn ratio value group (p trend = 0.047). In addition, the results from restricted cubic splines showed that the dose-response relationships of serum levels of these essential elements with the risk of endometrial diseases were nonlinear for Se, Cu, and Zn and relatively linear for Mo and Cu/Zn ratio. The present study showed serum levels of Zn and Se among women with endometrial diseases were significantly lower compared to that among healthy women, while serum levels of Cu and Mo were significantly higher, in addition, the serum Cu/Zn ratio value was also significantly and positively associated with the risk of endometrial diseases.

Artificial Intelligence of Object Detection in Skeletal Scintigraphy for Automatic Detection and Annotation of Bone Metastases.

BACKGROUND: When cancer has metastasized to bone, doctors must identify the site of the metastases for treatment. In radiation therapy, damage to healthy areas or missing areas requiring treatment should be avoided. Therefore, it is necessary to locate the precise bone metastasis area. The bone scan is a commonly applied diagnostic tool for this purpose. However, its accuracy is limited by the nonspecific character of radiopharmaceutical accumulation. The study evaluated object detection techniques to improve the efficacy of bone metastases detection on bone scans. METHODS: We retrospectively examined the data of 920 patients, aged 23 to 95 years, who underwent bone scans between May 2009 and December 2019. The bone scan images were examined using an object detection algorithm. RESULTS: After reviewing the image reports written by physicians, nursing staff members annotated the bone metastasis sites as ground truths for training. Each set of bone scans contained anterior and posterior images with resolutions of 1024 × 256 pixels. The optimal dice similarity coefficient (DSC) in our study was 0.6640, which differs by 0.04 relative to the optimal DSC of different physicians (0.7040). CONCLUSIONS: Object detection can help physicians to efficiently notice bone metastases, decrease physician workload, and improve patient care.