The ideal molecular imaging probe should have characteristics of specificity,sensitivity and safety.Aptamers are sing-strand DNA or RNA oligonucleotides which can bind their targets with high specificity and high affinity.Aptamers are new types of molecular imaging probe because they have many advantages,such as their large sum of possible targets,small molecule weights,easily production and modification,low immuno-genicity,high tissue penetration and so on.Now more and more aptamers research on tumor molecular imaging provides a new technology and tool for tumor diagnosis and therapy.

Objective To evaluate the outcome of dorsal double locking compression plate (LCP) in treatment of stretched unstable distal radial fractures.Methods Fourteen cases of stretched unstable distal radial fractures were treated by reduction and internal fixation using straight or L-shaped anatomic LCP via dorsal approach.Wrist functional exercise was conducted immediately after operation.Follow up was made after operation to assess motion pain,functional score of wrist,and complication incidence at postoperative 12 weeks,24 weeks,and 1 year.Results Follow-up was lasted for 5-24 months.At postoperative 12 weeks,24 weeks and 1 year,mean visual analogue scale (VAS) was (1.88 ±0.26) points,(0.87 ± 0.14) points and (0.37 ± 0.06) points respectively and wrist functional score (Gartland-Werley score) was (6.45 ± 1.72) points,(2.73 ± 0.52) points and (2.10 ± 0.31) points respectively.According to Garfland-Werley score in the latest follow-up,the results were excellent in 10 cases,good in two,and fair in two.Besides,one case was combined with myotenositis of extensor pollicis longus muscle tendon and another case with myotenositis of extensor tendon.Conclusion Dorsal double LCP is one of the effective methods for stretched unstable distal radial fractures that can reconstruct anatomical structure of the wrist efficiently and attain satisfactory functional recovery,with no obvious pain.

Chronic pancreatitis (CP) is a kind of disease with the sustainable and irreversible damage of the tissue structure and function of pancreas,which may be caused by alcohol,gene,gallstone,metabolism,deformity and other factors.The clinical manifestations are intractable abdominal pain and disorder of the internal and external secretion of pancreas.At present,the main purpose of the treatment for chronic pancreatitis is to relieve patients' pain,and to maintain the secretion function of pancreas as far as possible.The main surgical procedures for chronic pancreatitis includes the pancreatic resection,nerve block and decompression drainage of the pancreatic duct.In recent years,people hve paid more attenntion to the whole pancreas resection combined autologous transplantation due to retaining some functions of the islet cells.After whole pancreas resection combined autologous transplantation,the abdominal pain will relieve and the life quality will improved significantly.At the same time,it will effectively reduce the occurrence of pancretogenic diabetes since the surgery retains some function of the islet cells.

To determine the bufalin concentration in rats' plasma by establishing a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method, and to evaluate and compare the pharmacokinetic characteristics of bufalin-loaded bovine serum albumin nanoparticles (bufalin-BSA-NP) and bufalin.

This paper investigates the mechanism of radio-frequency(RF)heating that occurs when two adjacent orthopedic implants are present together under magnetic resonance imaging(MRI)at 1.5 Tesla and 3.0 Tesla.When a patient has multiple implants close to each other,interactions between the implants may increase RF heating.Typical generic interlocking plate and antibiotic nail implants are adopted as examples.To analyze the effect of adjacent implants,the amplitude and direction of incident and scattering vector electric fields at the hot spot position are calculated and extracted using numerical simulation based on Huygens principle.It is shown that a strong coupling effect occurs due to the existence of both the incident field and a strong scattering field.Huygens principle can be used to obtain the first and second order scattering fields generated between implants.If the first-and second-order electric field terms are summed within a certain region,the RF-induced heating of this dual-implant system increases.

In MRI examination, RF heating of implants will affect the safety of implant wearers. The conductivity of various tissues in the human body is significantly different, and the medium conductivity will affect the distribution of the RF electric field. Therefore, it is necessary to study the RF heating of different medium conductivity. Based on the analysis of the principle of MRI RF heating, this study build the model of the bird cage coil, ASTM standard phantom and lead, and the conductivity of several typical human tissues is selected as the conductivity in the experiment. Then calculate the power deposition of the lead at 64 MHz. The results show that the medium conductivity has no effect on the distribution of electric field and power deposition, and the hot spot distribution remains unchanged under different conductivity; The smaller the conductivity is, the larger the power deposition of the lead is, and the greater the temperature rise of the lead caused by RF heating is; The change of conductivity and power deposition is approximately linear. At the limit of 2 W/kg whole body specific absorption rate(SAR), the conductivity decreases, and the wire power deposition increases sharply.

ISO/TS 10974 is a general international technical specification (TS) which concentrates on the safety assessment of magnetic resonance imaging (MRI) for active implantable medical devices. ISO/TS 10974 Ed.2 was published in 2018 with substantial revision to Ed.1. To provide a guideline for adopting this recently revised TS in practice, this paper summarized the major changes and analyzed the technical improvements in Ed.2. Moreover, we also discussed current and emerging challenges to MRI safety evaluation remaining in Ed.2. The study revealed the consistency between these two editions with respect to classification of potential patient hazards and testing strategies, whereas Ed.2 has many methodological improvements over Ed.1 in testing methods for RF-induced heating, gradient-induced malfunction, and combined field testing, etc. However, it is still necessary to expand the scope of applicability and to adopt latest research findings into this TS to keep pace with the rapid developments in industry, making it a better guidance in the future.
Equipment Safety ; Humans ; Magnetic Resonance Imaging ; Prostheses and Implants

Objective:To investigate the safety of warfarin for Kawasaki disease (KD) with coronary artery aneurysm (CAA) and its prognosis.Methods:Twenty one children with KD complicated with giant CAA, multiple CAA in one coronary artery or thrombosis in coronary artery were enrolled in this prospective study. Warfarin was used to control the goal international normalized ratio (INR) ranging from 2.0 to 3.0. The CAA diameter, number, location and thrombus in coronary artery were recorded at the beginning of treatment, 1, 2, 3, 4 weeks and 2, 3, 6, 12 months after treatment, as well as the influence on INR, electrocaroliogram, creatine kinase-MB (CK-MB), troponin I. Standardized warfarin bleeding risk training and management was implemented. Children were divided into implementation group and non-implementation group according to the status of actual implementation of their parents. The incidence of bleeding events was compared between the two groups. Comparisons between groups were performed using a Rank sum test and a Fisher exact test.Results:In the 21 patients (15 males and 6 females), the age of onset ranged from 2 months to 6 years. There were 4 cases with grade Ⅱ, 7 cases with grade Ⅲ, 7 cases with grade Ⅳ and 3 cases with grade Ⅴ according to the severity of coronary arterial lesions before treatment. The time of clinical detection of thrombus in 10 children with thrombosis ranged from the fourth day to the fourth month. The dose distribution of warfarin was 0.06-0.10 mg/(kg·d), and the INR was 1.80-2.59. Among the 10 cases with thrombus, 8 cases had disappearance of thrombi and 2 cases with grade Ⅴ had thrombus organization to different degree. After treatment, the coronary artery ectasia of the 4 cases with grade Ⅱ all returned to normal. Among the 7 cases with grade Ⅲ, 3 cases of coronary artery aneurysms returned to normal, and 4 cases did not change. Among the 7 cases with grade Ⅳ , 5 cases of coronary artery aneurysms shrank to grade Ⅲ, and 2 cases remained unchanged. Three cases with grade Ⅴ lesions had no changes in aneurysm. Neither new thrombus nor new CAA was detected during the treatment. There was no significant change in electrocardiogram before and after treatment. No statistically significant difference was found regarding the troponin I (0.07 (0-3.01) vs. 0.04 (0-0.29) μg/L, Z=0.932, P>0.05) and CK-MB (20.6 (11.2-58.2) vs. 29.0 (16.7-47.0) U/L, Z=1.906, P>0.05) before and after treatment. The incidence of bleeding events in the implementation group was significantly lower than that in the non-implementation group (2/15 vs. 4/6, Fisher=5.689, P=0.031). Conclusions:The application of goal INR of 2.0-3.0 and adjustment of warfarin dose according to the severity of CAA combined with standardized and strict warfarin bleeding risk training and management, can increase the safety of warfarin therapy in children with KD, improve the prognosis of coronary artery lesions, promote the dissolution of thrombi, prevent new thrombosis, and effectively reduce the incidence of bleeding complication.

In magnetic resonance examination,the interaction between implants and the radio frequency(RF)fields induces heating in human tissue and may cause tissue damage.To assess the RF-induced heating of implants,three steps should be executed,including electromagnetic model construction,electromagnetic model validation,and virtual human body simulations.The crucial step of assessing RF-induced heating involves the construction of a test environment for electromagnetic model validation.In this study,a hardware environment,comprised of a RF generation system,electromagnetic field measurement system,and a robotic arm positioning system,was established.Furthermore,an automated control software environment was developed using a Python-based software development platform to enable the creation of a high-precision automated integrated test environment.The results indicate that the electric field generated in this test environment aligns well with the simulated electric field,making it suitable for assessing the RF-induced heating effects of implants.

Brain-computer interface(BCI)devices are crucial tools for neural stimulation and recording,offering broad prospects in the diagnosis and treatment of neurological disorders.Furthermore,magnetic resonance imaging(MRI)is an effective and non-invasive technique for capturing whole-brain signals,providing detailed information on brain structures and activation patterns.Integrating the neural stimulation/recording capabilities of BCI devices with the non-invasive detection function of MRI is considered highly significant for brain function analysis.However,this combination imposes specific requirements on the magnetic and electronic performance of neural interface devices.The interaction between BCI devices and MRI is initially explored.Subsequently,potential safety risks arising from their combination are summarized and organized.Starting from the source of these hazards,such as the metallic electrodes and wires of BCI devices,the issues are analyzed,and current research countermeasures are summarized.In conclusion,the regulatory oversight of BCI's magnetic resonance safety is briefly discussed,and suggestions for enhancing the magnetic resonance compatibility of related BCI devices are proposed.