BACKGROUND:Hydroxyapatite is the main inorganic component of bone tissue.The polymer has the structure and function of a biomimetic extracellular matrix.The composites of hydroxyapatite and polymer have been widely studied. OBJECTIVE:To summarize the research status of hydroxyapatite composite polymer materials for bone tissue repair. METHODS:The articles collected in PubMed,Web of Science,CNKI and WanFang databases were searched from January 2010 to April 2023.The Chinese and English search terms were"hydroxyapatite,polymer,composites,degradability,bone defect,bone repair".Finally,75 articles were included for review. RESULTS AND CONCLUSION:Polymers often used in composite with hydroxyapatite for bone tissue repair include natural polymers(collagen,chitosan,alginate,serine protein,cellulose,hyaluronic acid,and polyhydroxybutyrate)and synthetic polymers[polylactic acid,polylactic acid-hydroxyacetic acid copolymer,poly(has-lactide),poly(amino acid)and poly(vinyl alcohol)].The mechanical properties and osteoinductivity of hydroxyapatite/polymer composites were improved compared with pure hydroxyapatite.Hydroxyapatite composite with polymers can be made into porous scaffolds,hydrogels,and coatings for bone repair.Hydroxyapatite/polymer composites can accelerate bone reconstruction with a slow release of loaded drugs and cytokines due to their bionic extracellular matrix structure and function.Based on the diversity of causes of bone defects and the fact that bone repair is a complex continuous process involving multiple biological factors and proteins,repair materials with mechanical properties matching bone tissue,degradation processes synchronized with bone repair,and efficient osteogenesis and vascularization need to be further investigated.

Objective To establish a fluoroscopic percutaneous vertebral augmentation model in dogs by measuring and analyzing canine spinal anatomy.We also assessed the effectiveness and safety of this modeling method by postoperative radiological analysis.Methods Morphological measurements were taken in six dogs,aged approximately 12～24 months,and the following parameters of the lumbar vertebrae were determined:height of the L1～L7 vertebrae,width of the vertebral base,distance from the upper edge of the intervertebral disc to the narrowest part of the vertebra,distance from the vertical line of the spinous process to the upper edge of the intervertebral disc,and vertical distance from the midpoint of the transverse process to the lower edge of the intervertebral disc.These measurements were obtained to clarify the anatomical characteristics of the canine vertebrae and determine the optimal location,direction,and depth for bone-cement injection.A percutaneous vertebral augmentation model was subsequently established in the L4,L5,and L6 vertebrae of six healthy Beagle dogs,weighing 20～25 kg.The dogs were euthanized 4 weeks post-surgery and examined radiologically.Primary observations included the surgical duration,postoperative distribution of the implanted bone cement,and integrity of the vertebral canal and anterior edge of the vertebrae.Results Anatomical observation of the canine vertebrae revealed that the vertebral height increased gradually from L1～L5 and then decreased from L5～L7.The width of the vertebral base increased consistently from L1～L7.The distance from the vertical line of the spinous process to the upper edge of the intervertebral disc showed an increasing trend from L1～L7(1.9～4.0 mm).The distance between the midpoint of the base of the transverse process and the lower edge of the intervertebral disc increased gradually from L1～L5(4.7～6.9 mm).There was no significant difference in the distance between the midpoint of the base of the transverse process and the lower edge of the intervertebral disc in the L4,L5,and L6 segments among the dogs(P=0.925).The midpoint of the root of the transverse process of the spine was taken as the puncture point,and the insertion direction and horizontal plane were at an angle of 20°～30°,with a head tilt of 5°～15° and a puncture depth of 1.2～1.5 cm.If the puncture was directed towards the caudal side of the vertebra,the angle of the needle tail was 30°～35°,with a penetration depth of 1.5～1.8 cm.This technique allowed the successful construction of a canine vertebral puncture surgical model.A total of 15 canine vertebral puncture surgical models were successfully created,with an average surgery time of 22.7±4.6 min(15～30 min)per vertebral segment.During surgery,one vertebral segment experienced spinal cord injury result ing in paralysis of the hind limbs and bowel and bladder incontinence.Two vertebral cortical bones fractured,but there were no deaths due to anesthesia or infection.Four weeks post-surgery,micro-computed tomography-based three-dimensional reconstructions consistently showed bone cement distributed within the trabecular bone of the canine vertebrae,with newly formed bone tissue enveloping the implanted material.There was no leakage,and no complications such as damage to the vertebral canal or the anterior wall of the vertebrae.Conclusions A safe and reliable canine vertebral augmentation puncture model can be successfully established based on the anatomy of the canine lumbar vertebrae(L4～L6)and using the midpoint of the base of the transverse process as a bony landmark.

Humans ; Sleep, REM ; Memory ; Sleep ; REM Sleep Behavior Disorder

Brain/metabolism* ; Oxytocin ; Light

Objective:To explore the effect of different post-processing parameters of digital radiography (DR) on the quality of chest X-ray for pneumoconiosis diagnosis, and to provide suggestions on parameter setting suitable for this kind of DR machine.Methods:From January 1, 2022 to June 30, 2022, the chest films of 35 workers in the department of radiology of Hangzhou occupational disease prevention and treatment hospital were randomly selected and printed after setting different image post-processing parameters. The quality of chest film was evaluated by the measurement of optical densitometer and the combination of subjective and objective by professional physicians.Results:When the density is set to 2 and the contrast/detail contrast is 4.5, the optical density of each area of DR chest film meets the requirements of chest X-ray quality, and the qualified rate of physician quality evaluation is the highest.Conclusion:Reasonable setting of image post-processing parameters can improve the quality of chest radiograph.

Objective:To explore the effect of different post-processing parameters of digital radiography (DR) on the quality of chest X-ray for pneumoconiosis diagnosis, and to provide suggestions on parameter setting suitable for this kind of DR machine.Methods:From January 1, 2022 to June 30, 2022, the chest films of 35 workers in the department of radiology of Hangzhou occupational disease prevention and treatment hospital were randomly selected and printed after setting different image post-processing parameters. The quality of chest film was evaluated by the measurement of optical densitometer and the combination of subjective and objective by professional physicians.Results:When the density is set to 2 and the contrast/detail contrast is 4.5, the optical density of each area of DR chest film meets the requirements of chest X-ray quality, and the qualified rate of physician quality evaluation is the highest.Conclusion:Reasonable setting of image post-processing parameters can improve the quality of chest radiograph.

Objective:To investigate the differences of white matter diffusion properties between vulnerable and resistant individuals to continuous attention after sleep deprivation.Methods:According to the psychomotor vigilance test performance before and after sleep deprivation, the participants were divided into the vulnerable group( n=24) and resistant group( n=25). All participants underwent diffusion tensor imaging (DTI) scans.Tract based spatial statistics(TBSS) was used to compare fractional anisotropy(FA), mean diffusivity(MD), axial diffusivity(AD), radial diffusivity(RD) maps between the two groups.Spearman correlation analysis was conducted by SPSS 24.0 to investigate the relationships between the altered DTI metrics and PVT task performance. Results:(1) Compared with resistant group, FA value of vulnerable group decreased in the body of corpus callosum(x, y, z=-8, 9, 25, t=-7.855), right superior longitudinal fasciculus(x, y, z=-39, -7, 26, t=-6.252), bilateral anterior limb of internal capsule(x, y, z=-13, 8, 13, t=-5.235; x, y, z=12, 8, 3, t=-5.024) and right posterior thalamic radiation(x, y, z=-26, -56, 17, t=-5.469)(TFCE corrected, P<0.05, cluster size≥50 voxel). (2) Compared with resistant group, MD value of vulnerable group increased in the body of corpus callosum(x, y, z=-3, -6, 26, t=7.613), right superior longitudinal fasciculus(x, y, z=-31, -19, 38, t=5.314), bilateral anterior limb of internal capsule(x, y, z=-16, 7, 8, t=6.898; x, y, z=15, 5, 7, t=6.652), splenium of corpus callosum(x, y, z=27, -53, 17, t=6.541), and AD value increased in the right superior longitudinal fasciculus(x, y, z=-33, -19, 39, t=4.892), splenium of corpus callosum(x, y, z=-22, -49, 21, t=5.450), genu of corpus callosum(x, y, z=4, 26, 0, t=4.332), as well as RD value increased in the right superior corona radiata(x, y, z=-17, 1, 33, t=7.558), body of corpus callosum(x, y, z=4, -8, 26, t=6.699), right anterior limb of internal capsule(x, y, z=-12, 7, 3, t=5.212) (TFCE corrected, P<0.05, cluster size≥50 voxel). (3) Correlational analysis revealed that the negative correlations were found between PVT task performance and the FA value in the right superior longitudinal fasciculus( r=-0.492, P<0.001), right anterior limb of internal capsule( r=-0.510, P<0.001), right posterior thalamic radiation( r=-0.502, P<0.001) and body of corpus callosum( r=-0.464, P<0.001). The positive correlations were found between PVT task performance and the MD value in the body of corpus callosum( r=0.500, P<0.001), right superior longitudinal fasciculus( r=0.499, P<0.001), splenium of corpus callosum( r=0.462, P<0.001), right anterior limb of internal capsule( r=0.471, P<0.001), and AD value in right superior longitudinal fasciculus( r=0.643, P<0.001), as well as RD value in right superior corona radiate( r=0.498, P<0.001) (Bonferroni corrected, P<0.003). Conclusion:Differences in the microstructural characteristics of white matter fiber tracts in specific brain regions may constitute the potential neuropathological basis for the phenotypes of vulnerable and resistant individuals to continuous attention after sleep deprivation.

The liver imaging reporting and data system (LI-RADS) is an imaging assessment system that standardizes the diagnosis of hepatocellular carcinoma (HCC), indicating the benign and malignant tumor through categories as well as major and ancillary features. The higher the LI-RADS category ranking, the higher the corresponding HCC likelihood and malignancy risk. Therefore, early diagnosis and prediction of the prognostic risk factors of liver tumors by preoperative imaging have important clinical significance for improving the survival rate and prognosis of patients. This article reviews the research progress of LI-RADS categories and related imaging features in predicting the prognosis of liver tumors.

Pneumoconiosis is a serious occupational disease in China. Early imaging examination is one of the important measures for the diagnosis, treatment and prevention of pneumoconiosis. Digital radiography (DR) and computed tomography (CT) play an important role in the screening and diagnosis of pneumoconiosis, as well as the recent rise of artificial intelligence (AI) technology. This paper reviews the latest progress in technical parameter debugging and quality control of DR, optimization of AI computer-aided system and CT-aided diagnosis of pneumoconiosis, summarizes the advantages and problems in the application of the three technologies, providing research directions for imaging diagnosis of pneumoconiosis.