BACKGROUND:Black phosphorus has a high degree of homology with human bone,so it has been extensively studied in the field of bone tissue engineering in recent years.Since 2014,two-dimensional black phosphorus materials have garned significant attention in the field of biomedicine due to their excellent exceptional physical,chemical,and biological properties. OBJECTIVE:To summarize the advancements made in black phosphorus-based nanomaterials for bone tissue engineering,focus on the synthesis methods,osteogenic characteristics,and applications in biomaterials pertaining to two-dimensional black phosphorus nanomaterials. METHODS:Chinese and English key words were"black phosphorus,bone tissue engineering,bone defect,bone regeneration,osteogenesis."Relevant articles in PubMed and CNKI databases from January 2014 to December 2023 were searched.After exclusion and screening,96 articles were analyzed. RESULTS AND CONCLUSION:Black phosphorus nanomaterials play an important role in bone tissue engineering due to their good biocompatibility,biodegradability,photothermal action,antibacterial ability,drug loading performance,and special osteogenic effect,and are ideal candidate materials for promoting bone regeneration.The preparation of black phosphorus nanomaterials is mainly a top-down top-layer stripping method.The main principle is to weaken the van der Waals force between the black phosphorus layers by physical or chemical means to obtain a single or less layer of phosphanse,that is,black phosphorus nanosheets or quantum dots.Black phosphate-based nanocomposites are mainly divided into hydrogels,3D printing scaffolds,composite scaffolds,electrospinning,bionic periosteum,microspheres,and bionic coatings.The research of nano-black phosphorus in bone tissue engineering is in its infancy,and still faces many challenges:the behavior of black phosphorus in vivo and the interaction mechanism with various biomolecules need to be further studied.The long-term potential toxicity of black phosphorus is unknown.The manufacturing process for black phosphorus is difficult to control.Therefore,how to develop uniform size,safe,reliable,and efficient nano black phosphorus and transform it into clinical application requires interdisciplinary research on modern biomedical technology,physicochemical technology,and precision manufacturing technology.

Using high-energy proton to image the region of interest can directly obtain the accurate estimation of the proton stopping power of the lesions,which is of great significance to reduce the range uncertainty in proton therapy.As a fundamental function of proton computed tomography(CT),radiographic imaging plays a crucial role in assisting clinical positioning.The study develops a compact proton CT detector based on an active array pixel CMOS chip in Monte-Carlo simulation toolkit Geant4,and evaluates the radiographic imaging capability of the system using 180 MeV protons.The angles of tracks are successfully reconstructed.CTP404,CTP528,and the CTP515 of specific materials are used for simulation,obtaining the spatial and density resolutions,and measuring the proton relative stopping power(RSP).The image signal-to-noise ratio is improved when using 2° proton scattering angle cut-off value.The spatial resolution is 3-4 lp/cm measured using CTP528 module.The density resolution is better than 0.05 g/cm3,and the RSP resolution is within 5%when CTP404 module is used.Through the imaging of CTP515 phantom of specific material,it is demonstrated that the system has potential for imaging common human tissues.

Background::Exercise, as the cornerstone of pulmonary rehabilitation, is recommended to chronic obstructive pulmonary disease (COPD) patients. The underlying molecular basis and metabolic process were not fully elucidated.Methods::Sprague-Dawley rats were classified into five groups: non-COPD/rest ( n = 8), non-COPD/exercise ( n = 7), COPD/rest ( n = 7), COPD/medium exercise ( n = 10), and COPD/intensive exercise ( n = 10). COPD animals were exposed to cigarette smoke and lipopolysaccharide instillation for 90 days, while the non-COPD control animals were exposed to room air. Non-COPD/exercise and COPD/medium exercise animals were trained on a treadmill at a decline of 5° and a speed of 15 m/min while animals in the COPD/intensive exercise group were trained at a decline of 5° and a speed of 18 m/min. After eight weeks of exercise/rest, we used ultrasonography, immunohistochemistry, transmission electron microscopy, oxidative capacity of mitochondria, airflow-assisted desorption electrospray ionization-mass spectrometry imaging (AFADESI-MSI), and transcriptomics analyses to assess rectal femoris (RF). Results::At the end of 90 days, COPD rats’ weight gain was smaller than control by 59.48 ± 15.33 g ( P = 0.0005). The oxidative muscle fibers proportion was lower ( P < 0.0001). At the end of additional eight weeks of exercise/rest, compared to COPD/rest, COPD/medium exercise group showed advantages in weight gain, femoral artery peak flow velocity (Δ58.22 mm/s, 95% CI: 13.85-102.60 mm/s, P = 0.0104), RF diameters (Δ0.16 mm, 95% CI: 0.04-0.28 mm, P = 0.0093), myofibrils diameter (Δ0.06 μm, 95% CI: 0.02-0.10 μm, P = 0.006), oxidative muscle fiber percentage (Δ4.84%, 95% CI: 0.15-9.53%, P = 0.0434), mitochondria oxidative phosphorylate capacity ( P < 0.0001). Biomolecules spatial distribution in situ and bioinformatic analyses of transcriptomics suggested COPD-related alteration in metabolites and gene expression, which can be impacted by exercise. Conclusion::COPD rat model had multi-level structure and function impairment, which can be mitigated by exercise.

Compared with conventional radiotherapy, FLASH radiotherapy has advantages in protecting normal tissues, while the dose rate is increased by more than 100 times. If the shielding design of the treatment room is carried out according to the existing standard, the thickness and cost of the shielding wall will be significantly increased, or even hardly to meet the requirement of the standards, resultsing in the failure of the application of FLASH radiotherapy. By investigating the domestic and foreign standards and literature, this paper analyzes the challenges brought by FLASH radiotherapy technology to the shielding design of radiotherapy treatment room in China. Dose rate control standards adopted by different countries in the shielding design are emphatically compared as well. In several countries, the average dose rate under the actual treatment conditions was considered in the shielding design. In China, the method of instantaneous dose rate taking acount of occupancy factor is adopted. However, if FLASH radiotherapy technology is applied, the requirement of instantaneous dose rate will be difficult to meet. In order to improve the high dose rate radiotherapy technology such as FLASH radiotherapy, the revision of the existing standards is advised if the authorized limits are not changed. To use the average dose rate limit within a certain period of time for control, or to raise the control standard in the case of flash radiotherapy, are also avaliable.

Objective:To study the epidemiological characteristics of human brucellosis in high incidence areas of brucellosis in Gansu Province, and provide a guidance for precise prevention and control of brucellosis in the areas with high incidence of the disease.Methods:Using a retrospective research method, human brucellosis monitoring data from five high incidence counties of brucellosis in Gansu Province from 2018 to 2020, including Huan County (eastern), Guazhou County (western), Zhangjiachuan County (southern), Gaotai County (northern), and Jingtai County (central), were collected from monitoring database of the Central Transfer Payment Project. The epidemic characteristics of brucellosis in high incidence areas were described and analyzed.Results:From 2018 to 2020, there were a total of 787 laboratory confirmed cases of brucellosis in high incidence areas of brucellosis in Gansu Province, with a prevalence rate of 3.64%. The incidence rates for each year were 2.63% (205/7 780), 4.60% (327/7 111), and 3.78% (255/6 746), with statistically significant differences between different years (χ 2 = 41.44, P < 0.001). The prevalence rates of brucellosis in Huan County, Guazhou County, Zhangjiachuan County, Gaotai County, and Jingtai County were 0.02% (1/4 263), 3.67% (140/3 817), 4.32% (182/4 209), 4.89% (237/4 847), and 5.04% (227/4 501), respectively. There was a statistically significant difference in comparison between different regions (χ 2 = 211.59, P < 0.001). In 2018, the incidence rate was highest in Jingtai County in the central region, and scattered to Zhangjiachuan County in the south and Gaotai County in the north in 2019 and 2020. There were statistically significant differences in the prevalence rates among different genders, ages, ethnicities, educational levels, and occupational groups (χ 2 = 111.95, 212.76, 35.32, 89.59, 97.93, P < 0.001). From 2018 to 2020, the incidence of brucellosis in the < 20 (0.78%, 6.36%, 10.00%), 40 - 50 age groups (5.15%, 7.03%, 8.00%), students and young children (0.58%, 9.20%, 13.64%), and cadres (2.86%, 4.55%, 10.53%) showed an increasing trend year by year (χ 2trend = 21.55, 7.00, 30.63, 2.01, P < 0.001). Conclusions:The brucellosis in Gansu Province is still in a high level of growth stage, and the epidemic area is gradually dispersing; the cases are gradually becoming younger, and key occupational personnel are shifting from farmers and herdsmen to social workers. It is recommended to increase the scope of monitoring, increase publicity efforts, and enhance the self-protection and control awareness of key populations.

Objective:To introduce the clinical dosimetry commissioning methods and results of the 1.5 T MR-linac.Methods:In May, 2019, an Elekta Unity 1.5 T MR-linac was installed in Cancer Hospital, Chinese Academy of Medical Sciences and dosimetry commissioning was performed with magnetic field compatible measuring instruments. Commissioning items include absolute dose calibration, data acquisition and planning system model verification.Results:Absolute dose calibration in magnetic field should be corrected by magnetic field correction factor. The standard output dose of Unity was 87 cGy. Gamma analysis (3%/2 mm) was performed on the beam collection data and the planning system calculation data. The average pass rate of dose verification of standard field test cases was 96.41%, and the TG119 test case was 98.24%. The IROC end to end test case was 97.5%(7%/4 mm).Conclusions:The planning system model and the beam collection data have good consistency. The dose verification results of the standard field and TG119 test cases meet the general tolerance limit requirements of the AAPM TG218 report, and the verification results of the IROC end-to-end test cases meet the IROC center standards.

BACKGROUND: Anaplastic lymphoma kinase (ALK) is an important therapeutic target for advanced non-small cell lung cancer (NSCLC). In recent years, with the emergence of several ALK tyrosine kinase inhibitors (TKI), the overall survival (OS) of ALK fusion positive patients is gradually extended. This paper reports the treatment of a late stage non-small cell lung cancer (NSCLC) patient with ALK fusion positive for more than 5 years, and analyzes the treatment process and effect evaluation, so as to provide experience for the follow-up treatment of patients. METHODS: The diagnosis and treatment process of a patient with advanced ALK fusion mutation positive lung cancer admitted to the third ward of Department of oncology, Chifeng hospital, Inner Mongolia on July 3, 2015 was retrospectively analyzed. RESULTS: A 42 years old male patient was admitted to our department on July 3, 2015 for "intermittent cough, chest tightness for 2 months, diagnosed with lung adenocarcinoma for 1 day". Imaging examination showed a space occupying lesion in the left lower lobe of the lung, accompanied by mediastinal lymphadenopathy and left encapsulated pleural effusion. Bronchoscopic pathology showed non-small cell carcinoma, and adenocarcinoma was tentatively suggested. DIAGNOSIS: left lower lobe adenocarcinoma T1bN2M1a stage IV. Fluorescence in situ hybridization (FISH) indicated the translocation of ALK (2p23) chromosome. After 2 cycles of docetaxel+cisplatin (DP) regimens chemotherapy, disease progression occurred, so we used 6 cycles of pemetrexed+carboplatin to apply combination chemotherapy, 4 cycles of pemetrexed monotherapy were used after that. The efficacy evaluation: PR. On April 9, 2016, the patient was treated with crizotinib. In August 2019, multiple intracranial metastases were found and whole brain radiotherapy was given. Since September 4, 2019, oral administration of nsatinib has been carried out. As of March 1, 2021, the patients were followed up well. CONCLUSIONS The advanced ALK fusion positive lung adenocarcinoma patients, though the first-line and the second-line chemotherapy, and the follwing application of ALK-TKI treatment, has procured a total OS has reached 68 months, and the current follow-up is good.

Objective:To design a drum-shaped applicator through Monte Carlo simulation for breast intraoperative radiotherapy.Methods:Applicator designing process is as follows: first, determined the shape of the applicator based on the geometric characteristics of the breast tumor bed closed to the chest wall; second, calculated the scattering angle and dose rate of the electron beam after passing through a series of scattering foils of different thicknesses to determine the thickness of the scattering foil; thrid, modeled the layer according to the applicator′s geometric characteristics where modulator located, and designed the modulator through the relationship between the geometric characteristics of the layer and the surface dose of the applicator. EGSnrc/BEAMnrc and EGS4/DOSXYZ were employed to model the head of the Mobetron, the layer, the applicator, and to calculate the dose distributions.Results:The applicator has two components. The upper component is a 3cm-diametre cylindrical collimator with 0.5cm wall made of 0.3cm steel and 0.2cm water equivalent material (WEM), a 0.13cm-foil made of tansgen. The lower component is a 4cm-diametre drum made of 0.2cm WEM and a 0.14cm maximum thickness hill-shaped modulator made of steel. When the energy of electron beam was 12MeV, the dose rate was about 90.44 cGy/min, and the depth of the 50% isodose curve was 1cm.Conclusion:The applicator is successfully designed, and can obtain a drum-shaped dose distribution.

Objective:To design a semi-spherical applicator for delivery of semi-spherical dose distributions and assess its dosemetric characteristics.Methods:The applicator was designed in the following way. First, the scattering angle and dose rate of the electron beam having passed through a series of scattering foils of different thicknesses were calculated to determine the thickness of the scattering foil. And then, a series of location model was designed, and the variances of the mean electron energy on the surface of these models were calculated to determine the foil location. Finally, the relationship between the geometric characteristics of the layer and the surface dose on the applicator was established to design the modulator. Monte Carlo (MC) codes EGSnrc/BEAMnrc and EGS4/DOSXYZ were employed to model the head of the Mobetron, the location model, the layer, the semi-spherical applicator, and to calculate the dose distributions.Results:A semi-spherical applicator was designed for electron beam of energy 12 MeV, which consisted of a 2.5 cm diametre cylindrical collimator with 0.5 cm thick wall made of 0.3 cm thick steel and 0.2 cm thick water equivalent material (WEM), a 0.14 cm-thick foil made of tansgen, and a 2.5 cm diametre hollow semi-sphere containing a crescent modulator made of WEM. The dose rate was about 160 cGy/min, and the depth of the 50% isodose curve was 0.85 cm.Conclutions:We designed and performed a MC simulation of a semi-spherical applicator to deliver a semi-spherical dose distribution from a high energy electron beam.

Objective:To evaluate the effect of fast cone beam CT (CBCT) scan mode on image quality and registration results, and to establish the scanning pre-settings for fast CBCT.Methods:Three scanning modes were utilized to the CBCT phantom, and the registration accuracy and image quality were quantitatively evaluated. The correlation and consistency of measurement results under different scanning modes were further verified by 278 sets of CBCT data from 33 clinical tumor patients.Results:The maximum deviation between the measurement results of three scanning models and the actual value was 0.70 mm (0.51 mm on average). The measurement results of the same location were consistent among three scanning modes (0.00 mm). For the uniformity, the results of the normal mode were the best (3.62% on average), followed by the fast 1 mode (3.90% on average) and the fast 2 mode (4.84% on average). For the noise, the results of the normal mode were the best (15.69 on average), followed by the fast 2 mode (17.23 on average) and the fast 1 mode (21.74 on average). Regarding the high contrast resolution, the measurement results of three scanning modes were consistent (at least 3 pairs could be distinguished). For the low contrast resolution, the results of the fast 1 mode were the best (1.69 on average), followed by the normal mode (2.10 on average), and the fast 2 mode (2.31 on average). For the geometric accuracy, the measurement results of the three scanning modes were basically consistent with a mean deviation of 0.05 mm. The correlation of the measurement results between normal mode and fast 1 mode was the highest in clinical cases ( R2>0.90, P<0.01) with a high degree of consistency (95% consistency limit of the above two scanning modes< 1 mm threshold). Conclusion:Compared with the normal mode, the fast 1 mode can yield equivalent image quality, consistent registration results, faster scanning speed and lower scanning dose. Therefore, the fast 1 mode is recommended as the scan mode in clinical practice.