Objective:To evaluate the clinical application value of the adaptive aperture by comparing intensity-modulated proton radiotherapy(IMPT) plans using and not using the aperture for brain tumors.Methods:A total of twenty patients treated with postoperative radiotherapy for brain tumors were enrolled in this study. IMPT plans were developed for each patient using and not using the adaptive aperture under the same optimization conditions. The target conformal index (CI) value, target homogeneity index (HI) value, and the dose to normal tissues of the two sets of plans were compared.Results:The IMPT plans designed using the adaptive aperture significantly increased the mean CI value from 0.58 to 0.66, while decreasing the mean 50% prescription dose volume from 797.70 cm 3 to 638.15 cm 3. These plans also reduced the irradiation doses to the cochlea, brainstem, optic chiasm, optic nerve, and lens ( t = 2.06, 3.02, 2.11, 2.58, 2.67, P < 0.05). Additionally, there was no significant difference in the HI value of the target volumes and the machine jumps (MU) between the two sets of plans ( P > 0.05). Conclusions:The adaptive aperture can significantly reduce the irradiation dose to normal tissues outside the target volumes, positively impacting the protection of organs at risk (OARs) around the target values. This demonstrates its great potential for clinical application.

Objective To present and discuss beam characteristics of the first Mevion S250i gantry-mounted accelerator pencil beam scanning proton therapy system in China.Methods The output dose was measured using a parallel-plate ionization chamber.The integrated depth dose was measured with a large-radius Bragg peak ionization chamber,covering 19 energy levels ranging from 227 MeV to 28 MeV,to analyze the proton beam characteristics.The spots in the air were measured with Phoenix flat panel detector on the beam central axis,and the precision of the delivery position was verified by measuring the multi-spot beam map.The interleaf leakage and penumbra reduction of adaptive aperture were measured to characterize its performance.Results The proton system was calibrated for a maximum energy of 227 MeV,with a(10×10)cm2uniform field delivering 1 Gy dose at a depth of 5 cm underwater.The system effectively modulated the proton beam range to the patient's surface,maintaining a constant 80%-80%Bragg peak width of 8.6 mm at all energy levels.The spot size of the highest energy beam at the isocenter was about 4 mm in the air,and the spot delivery position error was less than 1 mm.The interleaf leakage rate of the adaptive aperture for the highest energy beam was below 1.5%,and the penumbra was significantly reduced.Conclusion Mevion S250i proton therapy system demonstrates unique design and beam characteristics,which is reflected in the Bragg peak shape,spot size variation with energy,and penumbra sharpening of adaptive aperture;and these differences should be considered in treatment planning system modeling and planning for precision treatment.

Traumatic fractures and stress fractures are common orthopedic diseases,and there is great potential in researching bone turnover,repair,and promotion of fracture healing.Basic medical experiments often use animal models of long bone fractures in limbs to study the mechanisms of various interventions on fracture healing.Fracture healing is a complex process influenced by multiple factors and involves multiple molecules and pathways.Therefore,to explore the mechanisms more deeply,accelerate the translation of results,and improve the clinical efficacy,it is particularly important to choose the appropriate animal fracture modeling methods in experimental research.Based on this,this paper conducts a literature review of animal species and modeling methods commonly used for long bone fracture models in experimental research.It summarizes five methods:bone defect method,physical impact method,mechanical bending method,open osteotomy method,and drilling method.A side-by-side comparison of their advantages,disadvantages,and scope of application is made,aiming to provide suitable fracture models for studyingthe mechanisms of fracture healing interventions.

Objective:To discuss the acceptance test of beam performance and mechanical precision of the first Mevion type S250i proton therapy system in China,and verify the stability and reliability of that in clinical treatment.Methods:According to the requirements of acceptance report of manufacturer,the output and range of machine unit(MU),the accuracy and stability of size and position of beam spot,the penumbra and position accuracy of adaptive aperture(AA)of Mevion type S250i proton therapy system,as well as the tests of mechanical properties and functions of the requirement of clinical use,were checked and tested for acceptance.Results:The maximum deviation of MU output was 1.3%,and the maximum deviation of the range was 0.037 g/cm2,and the maximum distal fall-off was 0.465 cm,and the minimum range of energy modulation was 0.21 g/cm2.The maximum deviations of the size of beam spot and the maximum deviation of the position were respectively 0.07 cm and 0.05 cm.The maximum AA penumbra was 0.007 cm,and the AA position accuracy was less than 0.1 cm.Conclusion:The acceptance test of the Mevion type S250i proton therapy system indicates that the parameters of the beam performance and mechanical precision can meet the requirements of the acceptance contract and AAPM-TG224 report of manufacturer,which has verified the machine has better favorable stability and reliability.

Objective:To measure and assess relevant radiation doses at the radiotherapy site of the first domestic single-vault proton therapy system.Methods:The radiation levels of the therapy system during and after beam irradiation were measured, and annual effective doses were assessed for personnel at the site.Results:During beam irradiation, the highest radiation dose was detected at the shielded door of the equipment floor, with a gamma radiation level of 2.140 μSv/h and a neutron radiation level of 0.850 μSv/h. Neutron radiation disappeared immediately once the beams stopped. In contrast, the radiation activated originated mostly from gamma rays. A longer time after beams stopped was associated with lower induced radiation intensity at the same location. Furthermore, a farther distance from the irradiated object corresponded to lower induced radiation intensity at the same time. The assessment result reveal that the annual effective doses to the personnel were at the safe level, with physicists exposed to the highest dose of 2.138 mSv.Conclusions:The radiation level at the studied proton therapy site meets the safety requirement, and the treatment can be performed safely at this site.

Radioactive cell senescence refers to the phenomenon in which cells undergo functional and morphological changes after being exposed to ionizing radiation, resulting in a permanent cessation of cell cycle, usually accompanied by inhibition of cell proliferation. Radiation induced cellular aging is the result of multiple molecular mechanisms, including DNA damage, cell cycle regulation, oxidative stress, and inflammatory response. Excessive or abnormal accumulation of senescent cells in the brain not only promotes the development of neurodegenerative diseases such as radiation induced brain injury, but also releases a large number of cytokines from senescent cells that contribute to the recurrence of glioblastoma. This article provides a review of the relationship between radioactive cellular senescence and the incidence of radiation brain injury and recurrence of glioblastoma.

Objective To analyze the daily quality assurance(QA)measurement results of IBA Sphinx Compact device on the Mevion compact pencil beam scanning proton therapy system for evaluating its clinical application value in proton therapy.Methods The daily QA measurement of Mevion S250i proton therapy system was carried out with Sphinx Compact device for 30 consecutive days,and the measurement results were analyzed.Results The average deviation between the positioning laser and the image center was(0.42±0.27)mm in 30 days.All of the proximal and distal depth errors of the high-and low-energy pencil beams were within 0.50 mm.The position deviation of all the spots measured did not exceed 1.00 mm,and the size deviation was less than 7.5%.The deviation between the image center and the beam center was not more than 0.75 mm.The relative deviation of the flatness of the rectangular field was about 0.5%.The deviation of the output dose of the square field was within 1.0%.Conclusion The proton system daily QA measurement items recommended by AAPM TG-224 report can be accurately and rapidly measured with Sphinx Compact device.The device is a practical and efficient daily QA tool with high practical value in clinic.

ObjectiveTo investigate the social support status and influencing factors of schizophrenics in remission in Northeast Sichuan， and to provide ideas for improving their social support. MethodsFrom May to September 2020， a total of 533 patients who met the diagnosis criteria of the International Classification of Diseases， tenth edition （ICD-10） for schizophrenics in remission at the mental health institutions in Guangyuan， Bazhong and Dazhou cities were selected for the survey， and patients were assessed by self-made demographic and clinical data inventory and Social Support Rating Scale （SSRS）. Then the social support status of schizophrenic in remission and influencing factors were analyzed， meantime， the impact of the second round reimbursement policy of medical insurance benefits on their social support was addressed particularly. Results①The SSRS total score， objective support， subjective support， and utilization of support scores of schizophrenics in remission were lower than those of the national norm （t=5.065~30.382， P<0.01）. ②Univariate analysis showed that SSRS score was relatively high among patients with female gender （t=-3.632）， retired status （F=5.951）， married status （F=5.951）， spouse as primary caregiver （F=23.841）， annual household income >5 000 yuan （F=15.892）， patient's economic income （t=4.083）， and outpatient or online follow-up （F=3.954）， with statistically significant differences （P<0.05 or 0.01）. ③The total and dimensional scores of SSRS in patients with access to the second round medical insurance reimbursement were significantly higher than those without （t=10.195~25.103， P<0.01）. ④Multiple linear regression analysis denoted that gender， work status， marital status， primary caregivers， annual family income， economic income， follow-up visits and the second round medical insurance reimbursement were the factors influencing social support status of schizophrenics in remission （β=0.201~2.115， P<0.05 or 0.01）. ConclusionThe social support of schizophrenics in remission in Northeast Sichuan is below the national average， furthermore， their social support levels are affected by the gender， work status， marital status， primary caregivers， annual family income， economic income， follow-up visits and the second round medical insurance reimbursement， and the second round medical insurance reimbursement may ameliorate the social support status of patients.

The present study aimed to explore the correlation between agronomic traits and quality indexes of Dendrobium nobile and its application value in agricultural breeding. The cultivated strains of D. nobile in Hejiang-Chishui producing areas were extensively collected,and the main agronomic traits and quality indexes were measured. The agronomic traits with significant correlation with quality indexes were screened out by the correlation analysis,and then the parental lines and self-bred F_1 generation plants were furtherverified. Among 96 lines of D. nobile,the content of soluble polysaccharides showed a significant negative correlation with dendrobine( P < 0. 01),and no significant correlation with agronomic traits in stems and leaves. The content of dendrobine exhibited a significant positive correlation with the stem width-thickness ratio( at the largest cross section; P < 0. 01),and no significant correlation with other agronomic traits. Regression analysis further verified the positive correlation between dendrobine content and stem width-thickness ratio( R2> 0. 9). Two lines,JC-10 and JC-35,with significant differences in stem width-thickness ratio were screened out( P <0. 05). The corresponding F1 generation plants by self-pollination both showed that the dendrobine content was higher with greater stem width-thickness ratio( P < 0. 01). The experimental results suggested that within a certain range,the dendrobine content was higher in D. nobile with flatter stem. Therefore,in the breeding of D. nobile,this specific trait could be used for screening plants with high content of quality indexes such as dendrobine.
Agriculture ; Dendrobium/genetics* ; Plant Breeding ; Plant Leaves/genetics* ; Polysaccharides

Objective:To investigate the changes of default network functional connectivity (FC) in resting state of patients with insomnia disorder (ID).Methods:Fifty-six patients with insomnia disorder and fifty healthy controls were recruited. All subjects were assessed with Pittsburgh sleep quality index (PSQI), insomnia severity index (ISI), Epworth sleepiness score (ESS) and Hamilton depression scale (HAMD-17). All subjects were scanned with resting state functional magnetic resonance imaging (rs-fMRI). SPM12 and CONN18b were used to preprocess rs-fMRI data on MATLAB (R2013b).The medial superior frontal gyrus was defined as the seed point, and the differences in the functional connection strength of the two groups of subjects were compared. Pearson correlation analysis was performed between the FC value of the brain area with statistical significance and scores of PSQI and ISI.Results:(1)FC analysis showed that compared with the control group, patients with ID had abnormal default mode network (DMN) connection, as follows: FC of left medial superior frontal gyrus and left central anterior gyrus (MNI: x, y, z=-30, -15, 51) and anterior cingulate gyrus (MNI: x, y, z=-6, 24, 36), FC of right medial forehead between the last gyrus and the left central anterior gyrus (MNI: x, y, z=-48, -6, 48), FC of left anterior cuneiform and the left central back (MNI: x, y, z=-54, -18, 54) and left superior occipital gyrus (MNI: x, y, z=-21, -69, 30), FC of right precuneus and left central posterior gyrus (MNI: x, y, z=-60, -21, 48) was enhanced. The FC of left anterior cuneiform lobe and the right middle frontal gyrus (MNI: x, y, z=42, 33, 42) and the right angular gyrus (MNI: x, y, z=54, -51, 45), FC of right precuneus and left inferior temporal gyrus (MNI: x, y, z=-51, -12, -42) was weakened. (2)With the left medial superior frontal gyrus as the seed point, FC values in anterior cingulate gyrus ( r=0.451, 0.338, both P<0.01) and left anterior central gyrus ( r=0.324, 0.402, both P<0.05) were positively correlated with PSQI and ISI scores. With the right precuneus as the seed point, FC value of left posterior central gyrus was positively correlated with PSQI( r=0.333, P=0.013) and ISI scores( r=0.418, P=0.008), while FC value of left inferior temporal gyrus was negatively correlated with PSQI( r=-0.662, P=0.001) and ISI scores( r=-0.402, P<0.01).With the left precuneus as the seed point, FC value of left superior occipital gyrus was positively correlated with PSQI( r=0.438, P=0.001) and ISI scores( r=0.495, P=0.011). Conclusion:Patients with ID may have changes in the functional connection of multiple networks. The decrease of FC in DMN may be one of the potential causes of insomnia. The increase in FC between DMN and the visuospatial attention network may be the core of the mechanism of damage to the brain function network of insomnia link.