Research Progress and Prospect of Machine Learning in Bone Age Assessment

Abstract

Bone age assessment has always been one of the key issues and difficulties in forensic science. With the gradual development of machine learning in many industries, it has been widely introduced to imageology, genomics, oncology, pathology, surgery and other medical research fields in recent years. The reason why the above research fields can be closely combined with machine learning, is because the research subjects of the above branches of medicine belong to the computer vision category. Machine learning provides unique advantages for computer vision research and has made breakthroughs in medical image recognition. Based on the advantages of machine learning in image recognition, it was combined with bone age assessment research, in order to construct a recognition model suitable for forensic skeletal images. This paper reviews the research progress in bone age assessment made by scholars at home and abroad using machine learning technology in recent years.

MicroRNA-1202 plays a vital role in osteoarthritis via KCNQ1OT1 has-miR-1202-ETS1 regulatory pathway

BACKGROUND

This study aimed to explore the molecular mechanism of osteoarthritis (OA) and provide information about new genes as potential targets for OA treatment.

METHODS

Gene expression profile of GSE105027, including 12 OA serum samples (OA group) and 12 healthy serum samples (ctrl group), was downloaded. The differentially expressed miRNAs (DEMs) as well as miRNA-mRNAs interactions were investigated, followed by function and pathway investigation. Then the protein-protein interaction (PPI) network was performed. Furthermore, the long non-coding RNA (lncRNA)-miRNA-mRNA interactions (competing endogenous RNAs, ceRNAs) were investigated.

RESULTS

A total of 17 downregulated miRNAs were revealed between OA and ctrl groups. These DEMs such as has-miR-1202 were mainly enriched in GO functions like histone acetyltransferase binding and KEGG pathways like cellular senescence. The integrated PPI network analysis showed that has-miR-1202, has-miR-33b-3p, has-miR-940, has-miR-4284, and has-miR-4281 were 5 downregulated miRNAs in this network. Furthermore, the lncRNA-miRNA-mRNA interactions such as KCNQ1OT1-has-miR-1202-ETS1 were revealed in the present ceRNA network.

CONCLUSION

Key DEMs such as miR-33b-3p, miR-940, and miR-1202 may be involved in OA. miR-1202 may regulate OA development via histone acetyltransferase pathway binding function and cellular senescence pathway. Furthermore, KCNQ1OT1-has-miR-1202-ETS1 might be vital for the process of OA.

Tumor-on-a-chip for integrating a 3D tumor microenvironment: chemical and mechanical factors

Tumor progression, including metastasis, is significantly influenced by factors in the tumor microenvironment (TME) such as mechanical force, shear stress, chemotaxis, and hypoxia. At present, most cancer studies investigate tumor metastasis by conventional cell culture methods and animal models, which are limited in data interpretation. Although patient tissue analysis, such as human patient-derived xenografts (PDX), can provide important clinical relevant information, they may not be feasible for functional studies as they are costly and time-consuming. Thus, in vitro three-dimensional (3D) models are rapidly being developed that mimic TME and allow functional investigations of metastatic mechanisms and drug responses. One of those new 3D models is tumor-on-a-chip technology that provides a powerful in vitro platform for cancer research, with the ability to mimic the complex physiological architecture and precise spatiotemporal control. Tumor-on-a-chip technology can provide integrated features including 3D scaffolding, multicellular culture, and a vasculature system to simulate dynamic flow in vivo. Here, we review a select set of recent achievements in tumor-on-a-chip approaches and present potential directions for tumor-on-a-chip systems in the future for areas including mechanical and chemical mimetic systems. We also discuss challenges and perspectives in both biological factors and engineering methods for tumor-on-a-chip progress. These approaches will allow in the future for the tumor-on-a-chip systems to test therapeutic approaches for individuals through using their cancerous cells gathered through approaches like biopsies, which then will contribute toward personalized medicine treatments for improving their outcomes.

Flame Retardation of Natural Rubber: Strategy and Recent Progress

Natural rubber (NR) as a kind of commercial polymer or engineering elastomer is widely used in tires, dampers, suspension elements, etc., because of its unique overall performance. For some NR products, their work environment is extremely harsh, facing a serious fire safety challenge. Accordingly, it is important and necessary to endow NR with flame retardancy via different strategies. Until now, different methods have been used to improve the flame retardancy of NR, mainly including intrinsic flame retardation through the incorporation of some flame-retarding units into polymer chains and additive-type flame retardation via adding some halogen or halogen-free flame retardants into NR matrix. For them, the synergistic flame-retarding action is usually applied to simultaneously enhance flame retardancy and mechanical properties, in which some synergistic flame retardants such as organo-montmorillonite (OMMT), carbon materials, halloysite nanotube (HNT), etc., are utilized to achieve the above-mentioned aim. The used flame-retarding units in polymer chains for intrinsic flame retardation mainly include phosphorus-containing small molecules, an unsaturated chemical bonds-containing structure, a cross-linking structure, etc.; flame retardants in additive-type flame retardation contain organic and inorganic flame retardants, such as magnesium hydroxide, aluminum hydroxide, ammonium polyphosphate, and so on. Concerning the flame retardation of NR, great progress has been made in the past work. To achieve the comprehensive understanding for the strategy and recent progress in the flame retardation of NR, we thoroughly analyze and discuss the past and current flame-retardant strategies and the obtained progress in the flame-retarding NR field in this review, and a brief prospect for the flame retardation of NR is also presented.

Research Progress on Postmortem Changes of Computed Tomography Imaging Characteristics on Corpses

Abstract

Postmortem changes on corpses appear immediately after death, and can transform the original structure characteristics of the corpse to different degrees as well as show specific changes on computed tomography （CT） images, sometimes with false positives and false negatives, influencing the identification of injuries or diseases. This paper systematically summarizes the postmortem changes of computed tomography imaging characteristics on corpses, to further expand the application of virtopsy in the practices of forensic pathology identification, and provide reference for the identification of injuries, diseases and changes after normal death.

4284The combined use of radiofrequency-ablation and balloon-dilation (CURB) in the creation of a stable inter-atrial communication: first-in-man use for patients with severe pulmonary arterial hypertension

Background

Recent preclinical research has suggested that combined use of radiofrequency-ablation and balloon-dilation (CURB) had the potential to create a stable inter-atrial communication. However, the related clinical data is still absent.

Purpose

This study describes the first-in-man use of CURB in the patients with severe pulmonary arterial hypertension (PAH).

Methods

Under the guidance of fluoroscopy and intra-cardiac echocardiography, CURB was attempted in 3 patients with severe PAH (age: 35.0±12.1 years, one idiopathic PAH and two PAH related to repaired congenital heart disease). With the aid of 3D location system, fossae ovalis was ablated with radiofrequency. Then the graded balloon-dilation was performed after transseptal puncture, and radiofrequency-ablation was repeated around the rim of fenestration created with balloon-dilation. The exercise capacity and fenestration-size were followed up.

Results

CURB was performed successfully in all 3 patients, and pulmonary vascular resistance was 30.3±10.9 Wood units. The fenestration size was 5.0±1.0 mm (range: 4–6 mm), and systemic arterial oxygen saturation decreased by 4.7±0.6% (range: 4–5%). World Health Organization functional class increased by 1.6±0.5 (P<0.001) and cardiac index increased by 0.58±0.34 L/min/m2 (P<0.001). In addition, exercise capacity improved significantly (+63.7 meters, P<0.001). Follow-up (6.0±1.0 months; range: 5–7 months) showed that all fenestrations were stable (P=0.808), and no complication occurred.

Figure 1. The combined use of radiofrequency-ablation and balloon-dilation (CURB) was performed in the patient with severe PAH. Left figures showed the procedure of CURB. Middle figures showed the created fenestration with MSCT, and the morphology and size of fenestration was provided in the right-inferior panel. In addition, the sizes of right atrium and ventricle were alleviated with increase of left atrium. Right figures indicated that the fenestration-size was stable during follow-up (one week, one month and six months, respectively).

Conclusions

In patients with severe PAH, CURB is feasible and effective to create a stable inter-atrial communication. Further research was required to evaluate the long-term result of this novel approach.

ClinicalTrials.gov ID: NCT03554330.

Acknowledgement/Funding

National Natural Science Foundation of China (81670283) and Beijing Natural Science Foundation (7162160)

Whole-genome SNP data unravel population structure and signatures of selection for black plumage of indigenous chicken breeds from Jiangxi province, China

Ten indigenous chicken breeds were originally distributed in Jiangxi Province, China, and they define a critical component of Chinese chicken genetic resources. We have investigated the population genetics of seven Jiangxi chicken breeds using 600K chicken BeadChip SNP data. To provide a genome-wide perspective for the population structure of all 10 Jiangxi chicken breeds, we herein genotyped 78 additional individuals from the seven breeds and 63 chickens from three uninvestigated breeds-Yugan Black (YG), Nancheng Black (NC) and Wanzai Yellow using 55K chicken SNP arrays. We then explored merged data of 17 101 SNPs from 235 individuals to infer the population structure of the 10 breeds. We showed that NC and YG are two regional populations of the same breed, as individuals from the two populations clustered together to form a branch separate from the other breeds in the neighbor-joining tree, they always grouped together in multidimensional principal component analyses and they displayed an identical pattern of ancestral lineage composition. Hence, NC and YG should be considered a single breed in the state-supported conservation scheme. Moreover, we conducted a genome scan for signatures of selection for black plumage. bayescan and hapflk analyses of two contrasting groups (three black-feathered breeds vs. six non-black-feathered breeds) consistently detected 25 putative regions under selection. Nine pigmentation- associated genes (DCT, SLC24A5, SLC30A4, MYO5A, CYP19A1, NADK2, SLC45A2, GNAQ and DCP2) reside within these regions, and these genes are interesting candidates for black plumage and provide a starting point for further identification of causative mutations for black feathers in chicken.

Characteristic Changes and 3D Virtual Measurement of Lung CT Image Parameters in the Drowning Rabbit Model

OBJECTIVES

To use virtual anatomy technique in the analysis of post-mortem characteristic changes of CT images in the experimental drowning rabbit model and the related parameters in 3D virtual model, so as to explore its application value in the diagnosis of drowning in forensic pathology.

METHODS

A model of drowning rabbits was established, with animal models of hemorrhagic shock and mechanical asphyxia as the controls. CT scan was performed on the experimental animals, and the differences in imaging features between the groups were compared by morphological reading of the tomographic images. CT data were imported into Mimics 14.0 software for 3D modeling. The CT values and lung volumes were calculated by the software, and the differences on CT values and lung volumes brought by different causes of death were analyzed.

RESULTS

The CT images of lungs in the drowning group showed characteristic ground-glass opacity （diffuse and uniform density increase）. There were no obvious abnormalities in hemorrhagic shock group, and only a few similar changes were found in the mechanical asphyxia group. Compared with the controls, the CT values and the lung volumes in the drowning group were significantly increased P<0.05.

CONCLUSIONS

Based on post-mortem lung imaging, the combination of CT value and lung volume changes can effectively reflect the virtual anatomical features in drowning, and provide a diagnostic basis for the forensic identification of drowning.

Commercial Low-citrate Anticoagulation Haemofiltration in High Risk Patients with Frequent Filter Clotting

This study assessed the safety and efficacy of a commercial low-citrate concentration-based pre-filter replacement fluid during continuous veno-venous haemofiltration (CVVH) in patients with frequent filter clotting and high risk of bleeding. We used a commercial low-citrate fluid as pre-dilution replacement fluid during CVVH (citrate: 11 mmol/l (33 meq/l), sodium: 140 mmol/l, chloride: 108 mmol/l and potassium: 1 mmol/l). A calcium and magnesium infusion was delivered separately by central line for the maintenance of serum ionized calcium (Cai) and total magnesium (Mg). In this prospective observational study, 30 patients, 124 filters and 1,515 treatment-hours were observed. Median filter life of citrate CVVH was 9.5 hours. Filter life in the 48 hours prior to citrate CVVH was also observed. In the patients on prior non-anticoagulant CVVH (n=14) filter life increased significantly with citrate (9.5 hours vs 5 hours; P<0.0001). In patients on prior heparin CVVH (n=15), filter life was similar with citrate (10 hours vs 8 hours; P=0.68). However, in patients with prior early/frequent filter clotting despite heparin (n=11) filter life increased significantly (10 hours vs 7 hours; P=0.038). Of 411 serum Cai measurements, none showed a Cai<0.85 mmol/l and, of 84 observations, none showed a serum Mg<0.6mmol/l. One patient with sepsis and shock needed to cease citrate CVVH because of progressive ionized hypocalcaemia and increasing anion gap. No other adverse effects were observed. In selected patients, CVVH with a commercial low-citrate concentration solution as pre-filter replacement fluid and a simultaneous calcium and magnesium infusion protocol appears generally safe. Filter life was acceptable and superior to that achieved with previous treatment.

A Comparison of 4% Succinylated Gelatin Solution versus Normal Saline in Stable Normovolaemic Sheep: Global Haemodynamic, Regional Blood Flow and Oxygen Delivery Effects

The objective of this study was to compare the effects on regional blood flow and regional oxygen delivery of 4% succinylated gelatin solution (Gelofusine®, B. Braun) with those of normal saline. This was a randomised, controlled, crossover large animal study, which took place at the animal laboratory of university physiology institute. The subjects were seven merino cross-ewes.

We implanted flow probes around the aorta, coronary, renal and mesenteric arteries. We randomised animals to observation (control), normal saline (one litre over 15 minutes) or Gelofusine* (one litre over 15 minutes). We measured central haemodynamics, organ blood flows, arterial blood gases and haemoglobin every 30 minutes for 210 minutes.

Compared to control, both Gelofusine* and normal saline significantly and similarly increased mean arterial pressure, stroke volume, cardiac output and central venous pressure in the first hour (P <0.05). Such changes, however, were transient except for the increase in cardiac output seen with Gelofusine®. Normal saline significantly increased mesenteric blood flow in the first hour (P <0.05), while Gelofusine* caused a specific, sustained and progressive increase in renal blood flow and conductance (P <0.05). Both fluids increased urine output and creatinine clearance (P <0.05), but, due to haemodilution, both decreased renal oxygen delivery in the first hour (P <0.05).

Normal saline and Gelofusine® have transient, volume expansion-related systemic haemodynamic effects, which are greater for Gelofusine®. Saline had a more pronounced early effect on mesenteric blood flow, while Gelofusine* had a sustained and progressive greater effect on renal blood flow. The transient increase in urine output and creatinine clearance seen with both fluids occurred while renal oxygen delivery decreased.

Time-dependent Effects of Pressure during Preservation of Rat Hearts in an Isochoric System at Subfreezing Temperatures

BACKGROUND

Isochoric freezing systems enable ice-free preservation of biological matter at subfreezing temperatures under the increased hydrostatic pressure.

OBJECTIVE

To examine the effects of pressure and exposure period on rat hearts preserved in an isochoric chamber.

MATERIALS AND METHODS

Rat hearts were preserved in the UW solution in isochoric chambers at temperatures from -2°C to -8°C and pressure from the atmospheric level to 78 MPa for up to eight hours, with and without the addition of glycerol. Hearts were evaluated via Langendorff perfusion and HE histology.

RESULTS

Hearts were compromised quickly as pressure increased, suggesting an acute time-pressure sensitivity. With the addition of 1 M glycerol, which reduces the pressure experienced at a given temperature, the survival time at -4°C was doubled.

CONCLUSION

The enhanced hydrostatic pressure encountered during isochoric preservation yields time-dependent negative effects on the heart, which can potentially be alleviated by the addition of a cryoprotectant.

Assessment of the Original Height of L1~2 after Vertebral Compression Fracture

OBJECTIVES

To explore the assessment method of original height of L_1-2 after vertebral compression fracture and its application value in forensic clinical practice.

METHODS

A total of 154 normal thoracic and lumbar X-ray films were collected, and 140 cases were used as experimental group while 14 cases as validation group. The heights of anterior （Ha） and posterior （Hp） vertebral body of T₁₂-L₃ vertebrae in each X-ray image were measured. In the experimental group, the correlation analysis between Ha_L₁ and Ha_T₁₂, Hp_T₁₂, Hp_L₁, Ha_L₂ and Hp_L₂ was carried out, and regression equation was established via fitting. The correlation analysis between Ha_L₂ and Ha_L₁, Hp_L₁, Hp_L₂, Ha_L₃, Hp_L₃ was performed, and the regression equation was also established via fitting. The difference between the predicted and measured values of Ha_L₁ and Ha_L₂ in validation group was compared.

RESULTS

In the 140 normal subjects, Ha_L₁ （y₁） was well correlated with Ha_T₁₂ （x₁） and Ha_L₂（x₂）, and the multiple linear regression equation was y₁=2.545+0.423 x₁+0.486 x₂ （determining coefficient R²=0.712, P<0.05; F=169.206, P<0.05）. There was no significant difference between the predicted and actual measured values of Ha_L₁ in the validation group （ P>0.05）. HaL₂ （y₂） was well correlated with Ha_L₁ （x₃） and Ha_L₃ （x₄）, and the multiple linear regression equation was y₂=4.354+0.530 x₃+0.349 x₄ （determining coefficient R²=0.689, P<0.05; F=151.575, P<0.05）. There was no significant difference between the predicted and actual measured values of Ha_L₂ in the validation group （ P>0.05）.

CONCLUSIONS

It is more appropriate to evaluate the original height of L₁ or L₂ single vertebrae by comparing with the height of the anterior edge of the upper and lower adjacent vertebral bodies.

Novel Core-Shell Hybrid Nanosphere towards the Mechanical Enhancement and Fire Retardance of Polycarbonate

It is a huge challenge to achieve highly efficient fire retardance with no mechanical damage to polymers. In our current research, a novel core-shell titanium dioxide@diphenylphosphinic (TiO₂@DPP) nanosphere was first synthesized through a hydrothermal reacting process, and applied in simultaneously enhancing the fire retardance and mechanical properties of polycarbonate (PC). The well-designed TiO₂@DPP exhibited a significant effect on combustion performance and mechanical reinforcement of PC. At only 0.10 wt % of TiO₂@DPP, PC/TiO₂@DPP passed the UL-94 V-0 rating, and its oxygen index value rose to 29.3%. Moreover, the peak value of the heat release rate was remarkably decreased by 34.1% in the combustion test, accompanied by the formation of more compacted char layer and the release of more incombustible gas. Equally important another aspect is that the PC containing only 0.10 wt % of TiO₂@DPP possessed higher elongation at break and higher tensile strength than pure PC, correspondingly increased by 27.7 and 14.7%. The analysis of the flame-retardant mechanism revealed that the improved fire retardance of PC is primarily ascribed to the barrier action of a cross-linking network containing phosphorus and titanium, the dilution of nonflammable gases such as H₂O, and the quenching effect of free radicals which are from the phosphorous group in the gas phase. All these experimental results demonstrate that the core-shell hybrid TiO₂@DPP may achieve a simultaneous significant improvement in fire retardance and mechanical properties of PC.

Search for Boosted Dark Matter Interacting with Electrons in Super-Kamiokande

A search for boosted dark matter using 161.9 kt yr of Super-Kamiokande IV data is presented. We search for an excess of elastically scattered electrons above the atmospheric neutrino background, with a visible energy between 100 MeV and 1 TeV, pointing back to the Galactic center or the Sun. No such excess is observed. Limits on boosted dark matter event rates in multiple angular cones around the Galactic center and Sun are calculated. Limits are also calculated for a baseline model of boosted dark matter produced from cold dark matter annihilation or decay. This is the first experimental search for boosted dark matter from the Galactic center or the Sun interacting in a terrestrial detector.