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As an important part of radiation therapy quality assurance, dose verification can verify the accuracy of the treatment dose to the patient’s tumor target area before treatment. At present, the dose verification technology has developed to the stage of three-dimensional dose verification. However, the existing clinical dose verification tools cannot meet the demand for three-dimensional dose verification in heavy ion therapy. In order to quickly and accurately realize three-dimensional dose verification of carbon ion therapy plan, a three-dimensional ionization chamber array was designed by using plexiglass PMMA(polymethyl methacrylate) as the ionization chamber wall and water equivalent phantom. And the structural design of the three-dimensional ionization chamber array was thoroughly studied and verified by Geant4 software. Firstly, by simulating the depth dose distribution of carbon ion beam deposited in water and PMMA phantom with different energies, the distal range ratio of the Bragg peak of the carbon ion beam in water and PMMA phantom was calculated, and the water equivalent thickness factor of PMMA phantom was characterized. Its value is 1.151. Then the effects of the spacing between adjacent ionization chambers and the signal leads on the accuracy of the dose measurement in the three-dimensional ionization chamber array were investigated. The signal crosstalk between adjacent ionization chambers mainly originates from the front ionization chamber, and the degree of crosstalk is inversely proportional to the spacing, the degree of crosstalk accounts for 3% of the dose within the ionization chamber at spacing of 1 mm, and the crosstalk effect can be completely eliminated at spacing of 30 mm. And the interference effect of the signal leads on the dose within the rear ionization chamber is about 1%. Finally, the dose distribution of 100 MeV/u and 200 MeV/u carbon ion beams deposited in the three-dimensional ionization chamber array was simulated, and the distal range of the Bragg peak was obtained in which the carbon ion beam was deposited. It has good agreement compared to the distal range of the Bragg peak in the PMMA phantom, and the deviation is 0.5 mm. The research show that the three-dimensional ionization chamber array can realize the three-dimensional dose verification of heavy ion therapy at the same time, and provides a reference for the development of three-dimensional ionization chamber array. The quality assurance level of carbon ion therapy should be further improved.

Abstract The HIV/AIDS cases and proportion in older people are continuously and rapidly increasing in China, especially in males. However, the transmission mechanism is not well understood. This study aims to explore the transmission mechanism of HIV/AIDS and potential ways to prevent or control HIV/AIDS transmission in a city in southwestern China. Data from multiple sources, including HIV/AIDS case reports in 2010–2020, a survey of HIV/AIDS cases in 2020, and sentinel surveillance data of female sex workers (FSWs) in 2016–2020 were analyzed. We explored the transmission mechanism of HIV/AIDS cases aged 50 years and older. In this city, the number of newly reported HIV/AIDS cases aged 50 years and older increased from 2010 to 2019, and decreased in 2020. The number of male and female cases aged 50 years and older both increased rapidly in 2017–2019, though the number of male cases was larger than that of female. The survey data showed that 84.7% of older male cases reported commercial sexual behavior, among whom 87.7% reported never using condom and 37.6% reported more than 10 times of commercial sexual behaviors in 1 year. In terms of price of sexual behavior, 68.3% of older male cases sought low-tier FSWs among whom the HIV/AIDS positive rate was 5.4% from the sentinel surveillance data. These results suggested HIV transmission between older men and low-tier FSWs through commercial sexual behavior. Among female cases aged 50 years and older, most reported non-marital and non-commercial heterosexual (60.5%) or regular sexual partner (31.4%) transmission, suggesting that they were infected by their spouse/regular sexual partner. Data of matched couples showed that most male cases had both marital sexual behavior and commercial sexual behavior, or acquired HIV through commercial sexual behavior, while most female cases had only marital sexual behavior. Based on these findings, we proposed a transmission mode of that local older male people and FSWs are transmitting bilaterally through commercial sexual behavior, and local older male people are spreading to local older female people through spouse or regular sexual partner route. By studying data from multiple sources, we explored the HIV transmission mode among older people. In the meantime, we found that marital status had a different impact on male and female old people in their sex behaviors.

Objective To analyze and summarize the clinical features of one patient with anti-GQ1b antibody syndrome presenting with rare and atypical manifestations of headache and visual disturbance. Methods Clinical data of a patient with anti-GQ1b antibody syndrome presenting with rare and atypical manifestations of headache and visual impairment were reported. Relevant case reports were retrieved from PubMed, Web of Science, CNKI and Wanfang Data using Chinese search terms of “visual disturbance”“visual impairment”“headache” and “head pain”, and English search terms of “GQ1b”“vision disorders”“visual disorders”“visual disturbance”“headache”“head pain” and “cephalalgia”, etc. Combined with literature review, the pathogenesis, clinical manifestations, laboratory and auxiliary examination and treatment prognosis of patients presenting with this type of manifestations were summarized. Results The 71-year-old male patient had a history of diarrhea at 3 weeks before the onset, manifested with headache and visual disturbance. Cerebrospinal fluid was detected for anti-GQ1b antibody （+） and anti-aquaporin 4 （AQP-4） antibody （-）. He was diagnosed with anti-GQ1b antibody syndrome. Headache symptoms were relieved by steroid treatment, and visual acuity was basically restored after 20 d. According to literature reviews, 9 patients with anti-GQ1b antibody syndrome were manifested with visual impairment and 5 patients presented with headache. All these patients had a history of pre-infection before the onset of disease. Serum or cerebrospinal fluid anti-ganglioside antibody detection contributed to early diagnosis. Prompt use of steroid hormone or immunoglobulin therapy yielded favorable prognosis. Conclusions Patients with anti-GQ1b antibody syndrome can only present with isolated atypical symptoms, such as headache and visual disturbance, if patients have pre-infection histories, early diagnosis and treatment should be performed.

In the construction of super high-rise buildings, building machines (BMs) are increasingly replacing traditional climbing frames. Building machine jacking operation (BMJO) is a high-difficulty and high-risk stage in the construction of the top mold system. To guarantee the operational safety of the BMJO and to enhance its intelligent control level, a digital twin (DT)-based monitoring method for the operation status of the BMJO is proposed. Firstly, a DT framework for monitoring the operation status of the BMJO is presented, taking into account the operational characteristics of the BM and the requirements of real-time monitoring. The functions of each part are then elaborated in detail. Secondly, the virtual twin model is created using Blender's geometric node group function; artificial neural network technology is used to enable online prediction of the structural performance of the BMJO and a motion model is established to realize a real-time state mapping of the BMJO. Finally, taking a BM project as an example, the DT system is established in conjunction with the project to verify the feasibility of the DT framework for monitoring the state of the BMJO. It is proved that the prediction results have high accuracy and fast analysis speed, thus providing a new way of thinking for monitoring and controlling the safe operation of the BMJO. [ABSTRACT FROM AUTHOR]

Objective To assess the long‐term clinical efficacy of TiRobot‐assisted percutaneous cannulated screw fixation in the treatment of femoral neck fractures. Methods This retrospective study included 50 patients with unilateral femoral neck fractures who were treated with TiRobot‐assisted percutaneous cannulated screw fixation from September 2017 to May 2018. After at least 2 years of follow‐up, the results of treatment, including operation duration, frequency of fluoroscopy use, intraoperative bleeding, hospital stay, medical expense, screw placement accuracy, rate of fracture healing and necrosis of the femoral head, and Harris hip scores at the last follow up, were recorded and compared with those of 83 matched patients who underwent conventional manual positioning surgery. Results The TiRobot group had longer operation duration (83.3 ± 31.2 min vs 44.1 ± 14.8 min) and higher medical expenses (28,407.1 ± 7498.0 yuan vs 22,672.3 ± 4130.3 yuan) than the conventional group. The TiRobot group had significantly less intraoperative bleeding (11.3 ± 7.3 mL vs 51.6 ± 40.4 mL) and shorter hospital stay (8.6 ± 2.8 days vs 11.1 ± 3.41 days) than the conventional group. Screw parallelism (1.32° ± 1.85° vs 2.54° ± 2.99° on anteroposterior radiograph; 1.42° ± 2.25° vs 3.09° ± 3.63° on lateral radiograph) and distance between screws (58.44 ± 10.52 mm vs 39.69 ± 12.17 mm) were significantly improved. No significant difference was found between the two groups in terms of the use of fluoroscopy (40.1 ± 28.5 times vs 38.6 ± 21.0 times) and Harris hip scores at the last follow‐up (93.2 ± 10.3 points vs 88.4 ± 11.9 points). Two cannulated screws penetrated the femoral head during manual insertion in the conventional group but not in the TiRobot group. The rate of nonunion and necrosis of the femoral head in the TiRobot group was reduced compared with that in the conventional group (0 vs 7.2%; 6.0% vs 24.1%). Conclusion TiRobot‐assisted percutaneous cannulated screw fixation of femoral neck fractures is accurate and minimally invasive and helps in reducing late complications, particularly necrosis of the femoral head and nonunion of fractures.

Two-dimensional (2D) monolayer transition metal dichalcogenides (TMDCs) that are compatible with Si-based substrates have already exhibited huge application potential in optoelectronics and photonics. The MoS2(1−x)Se2x ternary alloy consisting of two different chalcogens, as a class of lasing gain medium, enriches the family of 2D TMDC materials. Here, monolayer MoS2(1−x)Se2x ternary alloys with tunable composition have been synthesized via single-step chemical vapor deposition method. Raman and photoluminescence studies demonstrate that the bandgap of grown monolayer MoS2(1−x)Se2x alloys can be gradually tuned from 1.59 to 1.82 eV, indicating the continuous changes of the chemical composition x from 0.82 to 0. The oscillation characteristic is further investigated, where the MoS2(1−x)Se2x alloy provides optical gain for the SiO2 microsphere resonant cavity. The achieved resonance modes in a broadband range from 610 to 810 nm not only extend the range of potential TMDC-based lasers, but also drive the applications of alloy materials in various optoelectronics devices. [ABSTRACT FROM AUTHOR]

This article explores the potential use of pathobiome strains as live biotherapeutic products for human health. It emphasizes the importance of evaluating these strains at a detailed level, considering factors such as functional genes, ecological niche, and drug interactions. The article acknowledges the role of the gut microbiota in human health and discusses the potential benefits and risks of using pathobiome strains. It also addresses the challenges in developing these products, particularly in terms of safety, efficacy, and quality management. The authors propose further research into gene functions, ecological influences, and the pathogenicity of specific strains, and suggest expanding the applications of live biotherapeutics beyond gastrointestinal diseases. They discuss various development methods, such as large-scale screening and gene editing technology, and highlight the need for further investigation in this field. [Extracted from the article]

Covalent Organic Frameworks (COFs) demonstrate promising potential in the photocatalytic synthesis of H2O2 owing to favorable light absorption, superior charge separation, and considerable surface area. However, the efficiency of H2O2 photosynthesis is impeded by insufficient O2 adsorption sites and a high reaction barrier. In this work, various metal single atoms (Fe, Co, Ni) are introduced onto covalent triazine frameworks (CTFs) with N-N coordination sites to significantly enhance O2 adsorption and optimize H2O2 synthesis. Computational findings suggest that the presence of Fe, Co, and Ni not only enhances O2 adsorption but also exerts an influence on the reaction pathway of H2O2. Significantly, Fe exhibits a distinct advantage in modulating O2 adsorption through its unique electron spin state when compared to Co and Ni, as confirmed by crystal orbital Hamilton population (COHP) analysis. Additionally, this integration of metal atoms also improves light absorption and charge separation in CTFs. The study provides strategic insight into elevating H2O2 production by incorporating tailored metal single atoms into COFs. [ABSTRACT FROM AUTHOR]

Abstract Background The COVID-19 spread worldwide quickly. Exploring the epidemiological characteristics could provide a basis for responding to imported cases abroad and to formulate prevention and control strategies in areas where COVID-19 is still spreading rapidly. Methods The number of confirmed cases, daily growth, incidence and length of time from the first reported case to the end of the local cases (i.e., non-overseas imported cases) were compared by spatial (geographical) and temporal classification and visualization of the development and changes of the epidemic situation by layers through maps. Results In the first wave, a total of 539 cases were reported in Sichuan, with an incidence rate of 0.6462/100,000. The closer to Hubei the population centres were, the more pronounced the epidemic was. The peak in Sichuan Province occurred in the second week. Eight weeks after the Wuhan lockdown, the health crisis had eased. The longest epidemic length at the city level in China (except Wuhan, Taiwan, and Hong Kong) was 53 days, with a median of 23 days. Spatial autocorrelation analysis of China showed positive spatial correlation (Moran’s Index > 0, p