Objective:To investigate the dose characteristics of the Zeiss INTRABEAM system in air and water, providing dose reference for electronic brachytherapy.Methods:A Monte Carlo program was used to establish a three-dimensional model of a miniature X-ray source vacuum drift tube and a 4 cm spherical applicator. The process of electron beam bombardment on a gold target to generate X-rays was simulated, and parameters such as photon fluence spectrum, percentage depth dose, and half-value layer were calculated. Additionally, the radial dose uniformity in water was measured.Results:The average energy of X-rays at 3 cm in air was 20.8 keV, with a half-value layer of 0.08 mm Al. Under the influence of the applicator, the spectrum becomes hardened, with axial and radial average energies of 28.7 and 29.0 keV, respectively. In water, the percentage depth dose (PDD) curve follows an inverse cubic decay with depth, indicating strong dose concentration and rapid fall-off in near-field irradiation. The radial dose uniformity in water exceeded 99.5%.Conclusions:The INTRABEAM device emits low-energy X-rays characterized by shallow penetration depth, and concentrated dose delivery. Its highly uniform dose distribution ensures comprehensive coverage of the target area, making it particularly suitable for treating superficial tumors and for intraoperative radiotherapy at close range.

Objective:To investigate the dose characteristics of the Zeiss INTRABEAM system in air and water, providing dose reference for electronic brachytherapy.Methods:A Monte Carlo program was used to establish a three-dimensional model of a miniature X-ray source vacuum drift tube and a 4 cm spherical applicator. The process of electron beam bombardment on a gold target to generate X-rays was simulated, and parameters such as photon fluence spectrum, percentage depth dose, and half-value layer were calculated. Additionally, the radial dose uniformity in water was measured.Results:The average energy of X-rays at 3 cm in air was 20.8 keV, with a half-value layer of 0.08 mm Al. Under the influence of the applicator, the spectrum becomes hardened, with axial and radial average energies of 28.7 and 29.0 keV, respectively. In water, the percentage depth dose (PDD) curve follows an inverse cubic decay with depth, indicating strong dose concentration and rapid fall-off in near-field irradiation. The radial dose uniformity in water exceeded 99.5%.Conclusions:The INTRABEAM device emits low-energy X-rays characterized by shallow penetration depth, and concentrated dose delivery. Its highly uniform dose distribution ensures comprehensive coverage of the target area, making it particularly suitable for treating superficial tumors and for intraoperative radiotherapy at close range.

Objective To establish and evaluate a rapid detection method for SARS-CoV-2 based on reverse transcriptase-recombinase aided amplification(RT-RAA)combined with the clustered regularly interspaced short palindromic repeats(CRISPR)/Cas12a system.Methods RT-RAA primers and CRISPR-derived RNA(crRNA)were designed based on the nucleocapsid(N)gene of SARS-CoV-2 from NCBI database.The detection system was optimized with magnesium acetate(MgAc)concentration,RT-RAA reaction tempera-ture and time and LbCas12a reaction temperature.The sensitivity and specificity of the method were evaluated using recombinant plas-mids(100-106 copies/μL)and other respiratory pathogens.The RT-RAA-CRISPR/Cas12a method was compared with RT-PCR by tes-ting 70 clinical samples in parallel.Results The optimized RT-RAA-CRISPR/Cas12a assay could detect SARS-CoV-2 within 50 min at 37 ℃.The limit of detection was 10 copies/μL for the fluorescence-based method and 1×102 copies/μL for the lateral flow assay.The method specifically detected SARS-CoV-2 without cross-reactivity to other respiratory pathogens.The results of testing 70 clinical samples using RT-RAA-CRISPR/Cas12a showed agreement of 100％with those of RT-PCR.Conclusion The established RT-RAA-CRISPR/Cas12a assay for SARS-CoV-2 detection is rapid,cost-effective,highly sensitive and specific.It can be performed by less experienced personnel and no expensive equipment is required,thus it may provide a new approach for rapid clinical diagnosis and large-scale on-site screening of SARS-CoV-2.

Objective To establish a fluorescent assay for rapid detection of Plasmodium falciparum based on recombinaseaided amplification (RAA) and CRISPR-Cas12a system,and to preliminarily evaluate the diagnostic efficiency of this system.. Methods The 18S ribosomal RNA (rRNA) gene of P. falciparum was selected as the target sequence, and three pairs of RAA primers and CRISPR-derived RNA (crRNA) were designed and synthesized. The optimal combination of RAA primers and crRNA was screened and the reaction conditions of the system were optimized to create a fluorescent RAA/CRISPR-Cas12a system. The plasmid containing 18S rRNA gene of the P. falciparum strain 3D7 was generated, and diluted into concentrations of 1 000, 100, 10, 1 copy/μL for the fluorescent RAA/CRISPR-Cas12a assay, and its sensitivity was evaluated. The genomic DNA from P. vivax, P. malariae, P. ovum, hepatitis B virus, human immunodeficiency virus and Treponema pallidum was employed as templates for the fluorescent RAA/CRISPR-Cas12a assay, and its specificity was evaluated. Fifty malaria clinical samples were subjected to the fluorescent RAA/CRISPR-Cas12a assay and nested PCR assay, and the consistency between two assays was compared. In addition, P. falciparum strain 3D7 was cultured in vitro. Then, the culture was diluted into blood samples with parasite densities of 1 000, 500, 200, 50, 10 parasites/μL with healthy volunteers’ O-positive red blood cells for the RAA/CRISPR-Cas12a assay, and the detection efficiency was tested. Results The Pf-F3/Pf-R3/crRNA2 combination, 2.5 μL as the addition amount of B buffer, 40 min as the RAA reaction time, 37 °C as the reaction temperature of the CRISPR-Cas12a system were employed to establish the fluorescent RAA/CRISPR-Cas12a system. Such a system was effective to detect the plasmid containing 18S rRNA gene of the P. falciparum strain 3D7 at a concentration of 1 copy/μL, and presented fluorescent signals for detection of P. falciparum, but failed to detect P. ovum, P. malariae, P. vivax, T. pallidum, hepatitis B virus or human immunodeficiency virus. The fluorescent RAA/CRISPR-Cas12a system and nested PCR assay showed completely consistent results for detection of 50 malaria clinical samples (kappa = 1.0, P < 0.001). Following 6-day in vitro culture of the P. falciparum strain 3D7, 10 mL cultures were generated and the fluorescent RAA/CRISPR-Cas12a system showed the minimal detection limit of 50 parasites/μL. Conclusion The fluorescent RAA/CRISPR-Cas12a system is rapid, sensitive and specific for detection of P. falciparum, which shows promising value for rapid detection and risk monitoring of P. falciparum.

ObjectiveTo explore the effects of group interpersonal psychotherapy （IPT） on cognitive and social function in patients with first-episode schizophrenia， and to provide references for appropriate psychological treatment for the patients. MethodsA total of 62 patients with first-episode schizophrenia who met the diagnostic criteria of International Classification of Diseases， tenth edition （ICD-10） and were admitted to the Third People's Hospital of Foshan from January to December 2021 were selected as the study objects. And patients were divided into study group and control group according to random number table method， each with 31 cases. Both groups were treated with risperidone for 8 weeks， based on this， study group received group IPT. Before and after 8 weeks of treatment， Positive and Negative Syndrorne Scales （PANSS）， Wisconsin Card Sorting Tests （WCST） and Personal and Social Performance Sale（PSP） were adopted to assess the patients' psychiatric symptoms， cognitive function and social function. ResultsAfter 8 weeks of treatment， there was no significant difference in PANSS scores between the two groups （t=0.296， P>0.05）. The WCST total number of responses in the study group was larger than that in the control group， the number of perseverative errors and non-perseverative errors were smaller than those in the control group， and PSP score of the study group was higher than that of the control group， with statistically significant differences （t=0.398， 2.609， 0.523， 0.381， P<0.05 or 0.01）. ConclusionGroup IPT may have no significant efficacy on alleviating the symptoms of patients with first-episode schizophrenia， but it may help improve the cognitive and social function in patients.

ObjectiveTo explore the psychological defense styles and family environment among male prisoners of different terms of imprisonment， and to analyse the relationship between their psychological defense styles and family environment. MethodsA total of 200 male prisoners in a prison in Guangdong were randomly selected from April to June 2015， and they were classified into less than 5 years of imprisonment group （n=108） and 5 years or more imprisonment group （n=92）. Their defense style and family environment were evaluated by Defense Style Questionnaire （DSQ） and Family Environment Scale-Chinese Version （FES-CV）. Pearson correlation analysis was used to test the correlation between each scale score. ResultsThe factor scores of immature defense mechanism and intermediate defense mechanism of DSQ in the group with less than 5 years of imprisonment were lower than those in the group with 5 years or more imprisonment， with statistically significant differences （t=4.198， 1.137， P<0.01）. The scores of FES-CV family intimacy， emotional expression and organizational factors in less than 5 years of imprisonment group were higher than those in 5 years or more imprisonment group （t=3.122， 2.993， 2.203， P<0.01）， and the scores of contradiction factors were lower than those in 5 years or more imprisonment group （t=-3.682， P<0.01）. The scores of DSQ immature， intermediate defense mechanism and concealment factor of male prisoners were negatively correlated with the scores of FES-CV family intimacy and emotional expression factor （r=-0.428~-0.172， P<0.05 or 0.01）， and the scores of 4 factors in DSQ were all positively correlated with the scores of contradiction factor in FES-CV （r=0.175~0.384， P<0.05 or 0.01）. ConclusionCompared with male prisoners with less than 5 years of imprisonment， those with 5 years or more are prone to adopt immature and intermediate defense mechanisms， and their family environments are characterized by apparent contradiction and a lack of family intimacy， emotional expression and organization. Furthermore， the defects of psychological defense mechanism of prisoners are related to their family environment.

ObjectiveTo investigate the efficacy and safety of venlafaxine in the treatment of depression under the guidance of pharmacogenomics testing， and to provide references for individualized medication. MethodsA total of 66 patients who met the diagnostic criteria of International Classification of Diseases， tenth edition （ICD-10） for depressive episode were included in the study. Patients who were recommended to be treated with venlafaxine in the pharmacogenomics testing report were divided into study group （n=32）， and those who were decided to be treated with venlafaxine by doctors after consultation with patients were divided into control group （n=34）. At the baseline and the end of the 2^nd， 4^th， 6^th and 8^th weekend of treatment， Hamilton Depression Scale-24 item （HAMD-24） was adopted to evaluate the clinical efficacy. Meanwhile， Sheehan Disability Scale （SDS） was applied to measure the social function of patients at the baseline and the end of the 8^th weekend of treatment. After treatment， Treatment Emergent Symptom Scale （TESS） was used to assess the incidence of adverse reactions. ResultsAt the end of the 4^th， 6^th and 8^th weekend of treatment， HAMD-24 scores in the study group were all lower than those in the control group， with statistical differences （t=2.344， 4.316， 5.760， P<0.05 or 0.01）. At the end of the 8^th weekend of treatment， SDS score of the study group was lower than that of the control group， with statistical difference （t=2.173， P<0.05）. The adverse reaction rate in the study group was lower than that in the control group， with statistical difference （χ²=5.720， P<0.05）. ConclusionTreatment of depression with venlafaxine based on pharmacogenetic testing is an effective and safe way to alleviate the depression symptoms in patients.

Objective:The paper aims to analyze achievements and problems of interdisciplinary collaborative research between medicine and engineering carried out jointly by the First Hospital of Qinhuangdao and Yanshan University, to provide further reference for municipal hospitals.Methods:The data of scientific research of the medicine-engineering interdisciplinary collaboration in past 8 years were analyzed with specific focus on the characteristics, academic level and discipline distribution.Results:Academic level of the First Hospital of Qinhuangdao was significantly improved through such medicine-engineering interdisciplinary scientific research collaboration, especially in disciplines such as orthopaedics, rehabilitation medicine, medical imaging that are closely related to engineering disciplines.Conclusions:Deficiency of scientific research resources faced by municipal hospitals can be mitigated by medicine-engineering interdisciplinary collaboration with universities, and medicine-engineering interdisciplinary collaboration can be a possible way to improve academic level of municipal hospitals.

Objective:To discuss the causes and solutions for failed anterior ring fixation for unstable pelvic fractures.Methods:A retrospective analysis was conducted of the 84 patients who had been admitted to Department of Orthopedics and Joint Surgery, Jiangmen Central Hospital for unstable pelvic fractures from January 2009 to March 2019. They were 56 males and 28 females, aged from 19 to 64 years (mean, 42.5 years). By the Tile classification, 22 cases were type B1, 16 type B2, 10 type B3, 22 type C1, 6 type C2 and 8 type C3. Simple anterior ring fixation was performed for 21 cases and combined anterior and posterior ring fixation for 63 ones. The Matta's criteria were applied for the evaluation of fracture reduction. The cases of failed anterior ring fixation and their solutions were recorded and analyzed.Results:All patients were followed up for 6 to 36 months (average, 13.5 months). Failed anterior ring fixation was observed in 7 cases (8.3%) at 3 to 75 days after operation (average, 29.1 days). The failure was attributed to improper operation timing and unstable anterior ring fixation in 2 cases, mere unstable anterior ring fixation in one, wrong choice of anterior ring fixators and improper rehabilitation in 2 cases, poor intraoperative reduction in one and unstable posterior ring fixation in one. In the 2 failed cases that had been treated by external fixators, one underwent revision and the other conservative treatment. In the 5 cases that had been treated by plating, 4 underwent revision and one conservative treatment. By the Majeed criteria, the pelvic function was evaluated at the final follow-up as excellent in 2, good in 2 and fair in one in the 5 cases of revision who obtained follow-up from 11 to 24 months(average, 17.2 months) after revision; malunion was observed in the 2 cases of conservative treatment.Conclusions:Failed anterior ring fixation for unstable pelvic fracture may be caused by improper operation timing, wrong choice of anterior ring fixators, intraoperative malreduction, unstable pelvic ring fixation and improper rehabilitation. The key solution to failed anterior ring fixation is to find the specific causes. Plate revision may lead to fine therapeutic efficacy.

Objective: To investigate the clinical effect of preoperative computed tomography (CT) measurement of acetabulum femoral neck combined anteversion in primary total hip arthroplasty (THA). Methods: From March 2016 to may 2018, 48 patients (90 hips) with developmental dysplasia of the hip (DDH) who were treated with THA in the orthopaedic department of Jiangmen Central Hospital were measured by X-ray and spiral CT three-dimensional reconstruction technology before operation, and the best combined anteversion angle of acetabulum was determined before implementing THA, which was CT group; the remaining 42 patients were not measured by CT before operation, which was X-ray group. The difference of acetabulum cup anteversion angle, acetabulum femoral neck combined anteversion angle and preoperation angle were evaluated by three-dimensional computed tomography (3D-CT) in CT group. Results: There was no significant difference in operative time, intraoperative blood loss, time of getting out of bed and length of lower limbs between the two groups (P>0.05). In CT group, the acetabulum cup anteversion and acetabulum femoral neck anteversion were close to the pre-operative angle at 2 and 3 months postoperatively (P>0.05). The Harris hip score of CT group was significantly higher than that of X-ray group at 2 and 3 months after operation, and the incidence of deep vein thrombosis was 6.25%, significantly lower than that of X-ray group (21.43%) (P<0.05). The incidence of dislocation, infection and periprosthetic fracture was slightly lower than that of X-ray group, but the difference was not statistically significant (P>0.05). Conclusions For DDH patients who received THA for the first time, preoperative CT measurement of acetabulum femoral neck combined with anteversion is conducive to the formulation of the best combined anteversion adjustment scheme, which can obtain the maximum initial stability, improve the surgical effect and reduce the occurrence of dislocation of prosthesis.