206 research outputs found

    XRCC1 codon 399Gln polymorphism is associated with radiotherapy-induced acute dermatitis and mucositis in nasopharyngeal carcinoma patients

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    BACKGROUND: To evaluate the association between single nucleotide polymorphisms (SNPs) at the 194 and 399 codons of XRCC1, and the risk of severe acute skin and oral mucosa reactions in nasopharyngeal carcinoma patients in China. METHODS: 114 patients with nasopharyngeal carcinoma were sequentially recruited in this study. Heparinized peripheral blood samples were taken for SNPs analysis before the start of radiation treatment. SNPs in XRCC1 (194Arg/Trp and 399Arg/Gln) gene were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Dermatitis at upper neck and oral mucositis were clinically recorded according to the Common Terminology Criteria for Adverse Events v.3.0. RESULTS: The variant allele frequencies were 0.289 for XRCC1 194Trp and 0.263 for XRCC1 399Gln. Of the 114 patients, 24 experienced grade 3 acute dermatitis and 48 had grade 3 acute mucositis. The XRCC1 399Arg/Gln was significantly associated with the development of grade 3 dermatitis (Odds Ratio, 2.65; 95% CI, 1.04–6.73; p = 0.037, χ2 = 4.357). In addition, it was also associated with higher incidence of grade 3 mucositis with a borderline statistical significance (Odds Ratio, 2.11; 95% CI, 0.951–4.66; p = 0.065, χ2 = 3.411). The relationship between XRCC1 194Arg/Trp and acute dermatitis, and mucositis was not found. CONCLUSIONS: Our investigation shows, for the first time, that patients with the XRCC1 399Arg/Gln genotype were more likely to experience severe acute dermatitis and oral mucositis. With further validation, the information can be used to determine personalized radiotherapy strategy

    An Orderly Untangling Model against Arching Effect in Emergency Evacuation Based on Equilibrium Partition of Crowd

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    To untangle the arching effect of a crowd as much as possible in emergency evacuations, we employ a theoretical model of equilibrium partition of crowd batch. Based on the shortest time arrangement of evacuation, the crowd is divided into appropriate batches according to the occupied time of evacuation channel in order to determine the occupant number of every evacuation passageway. The number of each batch crowd is calculated under the condition that the time of entering the evacuation passageway is equal to the time of crossing over the evacuation passageway. Subsequently, the shortest processing time (SPT) rule establishes the evacuation order of each batch. Taking a canteen of China Three Gorges University as a background, we obtain the waiting time from the first person to the last one entering the evacuation channel in every batch by simulation. This research utilizes data from simulations to observe an untangling process against the arching effect based on the SPT rule. More specifically, evacuation time only lasts for 180.1 s in order and is 1.6 s longer than that in disorder, but the arching effect disappears. Policy recommendations are offered to improve the evacuation scheme in disaster operations

    Changes in bacterial community of soil induced by long-term straw returning

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    Straw returning is an effective way to improve soil quality. Whether the bacterial community development has been changed by long-term straw returning in non-calcareous soil is not clear. In this study, the following five treatments were administered: soil without fertilizer (CK); wheat and corn straw returning (WC); wheat straw returning with 276 kg N ha−1 yr−1 (WN); manure, 60,000 kg ha−1 pig manure compost (M) and wheat and corn straw returning with 276 kg N ha−1 yr−1 (WCN). The high-throughput 16S rRNA sequencing technology was used to evaluate the bacterial communities. The results showed that the community was composed mostly of two dominant groups (Proteobacteria and Acidobacteria). Bacterial diversity increased after the application of straw and manure. Principal component analyses revealed that the soil bacterial community differed significantly between treatments. The WCN treatment showed relatively higher total soil N, available P, available K, and organic carbon and invertase, urease, cellulase activities and yield than the WC treatment. Our results suggested that application of N fertilizer to straw returning soil had significantly higher soil fertility and enzyme activity than straw returning alone, which resulted in a different bacterial community composition, Stenotrophomonas, Pseudoxanthomonas, and Acinetobacter which were the dominant genera in the WC treatment while Candidatus, Koribacter and Granulicella were the dominant genera in the WCN treatment. To summarize, wheat and maize straw returning with N fertilizer would be the optimum proposal for improving soil quality and yield in the future in non-calcareous fluro-acquic-wheat and maize cultivated soils in the North China Plain in China

    Targeting ferroptosis: a promising strategy to overcome drug resistance in breast cancer

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    Breast cancer is one of the most prevalent malignancies affecting women worldwide, with its incidence increasingly observed in younger populations. In recent years, drug resistance has emerged as a significant challenge in the treatment of breast cancer, making it a central focus of contemporary research aimed at identifying strategies to overcome this issue. Growing evidence indicates that inducing ferroptosis through various mechanisms, particularly by inhibiting System Xc-, depleting glutathione (GSH), and inactivating glutathione peroxidase 4 (GPX4), holds great potential in overcoming drug resistance in breast cancer. It is anticipated that therapies targeting ferroptosis will emerge as a promising strategy to reverse tumor resistance, offering new hope for breast cancer patients. This review will explore the latest advancements in understanding ferroptosis in the context of breast cancer drug resistance, with a particular emphasis on the roles of ferroptosis inducers and inhibitors, and the impact of ferroptotic pathways on overcoming drug resistance in breast cancer

    Computational Fluid Dynamics Analysis of the Impacts of Air Supply Velocity Modes on the Differential Pressure Precooling Efficiency of Peaches Stored in Ventilated Packaging

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    In this study, a numerical model for heat and mass transfer in the differential pressure precooling of peaches stored in layered packaging under different precooling conditions was constructed based on computational fluid dynamics. Through the analysis of experimental and simulation data, it was found that the maximum root mean square error (RMSE) between the constructed numerical model and the experimental group was 0.796 7 ℃, and the mean absolute percentage error (MAPE) was 6.74%, which demonstrated the feasibility and authenticity of the modeling method. The precooling efficiencies of two air supply velocity modes were compared, demonstrating that compared with the constant velocity mode, the variable velocity mode ∆P1 + ∆P2 improved the uniformity of precooling and shortened the cooling time, and there was a seven-fold threshold relationship between ∆P2 and ∆P1. When ∆P2 was more than seven times as high as ∆P1 (∆P1 < 35 Pa), the uniformity of precooling was improved by about 10%–20%, and the precooling time was shortened by 50%-75%; however, the energy consumption cost increased by at least 8 times, and it increased exponentially with ∆P2. Therefore, the variable velocity mode should be selected when priority is given to the precooling quality and the transfer time to cold storage; in which (15 + 105) Pa is the optimal environmental parameter combination for peach precooling, while the constant velocity mode should be selected to achieve energy savings in precooling. This study provides a theoretical reference for small and medium-sized orchards to reasonably select air supply modes and accurately control the precooling efficiency of fruits

    MSMEG_2731, an Uncharacterized Nucleic Acid Binding Protein from Mycobacterium smegmatis, Physically Interacts with RPS1

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    While the M. smegmatis genome has been sequenced, only a small portion of the genes have been characterized experimentally. Here, we purify and characterize MSMEG_2731, a conserved hypothetical alanine and arginine rich M. smegmatis protein. Using ultracentrifugation, we show that MSMEG_2731 is a monomer in vitro. MSMEG_2731 exists at a steady level throughout the M. smegmatis life-cycle. Combining results from pull-down techniques and LS-MS/MS, we show that MSMEG_2731 interacts with ribosomal protein S1. The existence of this interaction was confirmed by co-immunoprecipitation. We also show that MSMEG_2731 can bind ssDNA, dsDNA and RNA in vitro. Based on the interactions of MSMEG_2731 with RPS1 and RNA, we propose that MSMEG_2731 is involved in the transcription-translation process in vivo

    Emergency tracheal intubation in 202 patients with COVID-19 in Wuhan, China:lessons learnt and international expert recommendations

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    Tracheal intubation in coronavirus disease 2019 (COVID-19) patients creates a risk to physiologically compromised patients and to attending healthcare providers. Clinical information on airway management and expert recommendations in these patients are urgently needed. By analysing a two-centre retrospective observational case series from Wuhan, China, a panel of international airway management experts discussed the results and formulated consensus recommendations for the management of tracheal intubation in COVID-19 patients. Of 202 COVID-19 patients undergoing emergency tracheal intubation, most were males (n=136; 67.3%) and aged 65 yr or more (n=128; 63.4%). Most patients (n=152; 75.2%) were hypoxaemic (Sao2 &lt;90%) before intubation. Personal protective equipment was worn by all intubating healthcare workers. Rapid sequence induction (RSI) or modified RSI was used with an intubation success rate of 89.1% on the first attempt and 100% overall. Hypoxaemia (Sao2 &lt;90%) was common during intubation (n=148; 73.3%). Hypotension (arterial pressure &lt;90/60 mm Hg) occurred in 36 (17.8%) patients during and 45 (22.3%) after intubation with cardiac arrest in four (2.0%). Pneumothorax occurred in 12 (5.9%) patients and death within 24 h in 21 (10.4%). Up to 14 days post-procedure, there was no evidence of cross infection in the anaesthesiologists who intubated the COVID-19 patients. Based on clinical information and expert recommendation, we propose detailed planning, strategy, and methods for tracheal intubation in COVID-19 patients

    LMS/RLS/OCTAVE Vibration Controls of Cold Orbital Forging Machines for Improving Quality of Forged Vehicle Parts

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    Cold orbital forging (COF) as an advanced incremental metal-forming technology has been widely used in processing vehicle parts. During the COF process, the vibration on the COF machine injures the service life of the machine and the quality of the forged part. The study of the vibration control of the COF machine is therefore necessary. In this study, the dynamic model of the COF machine is established, and the vibration performances of some key positions are obtained using Matlab&amp;Simulink software. Subsequently, the vibration performances are effectively verified by conducting a vibration test experiment. Based on the dynamics model of the COF machine and Matlab&amp;Simulink software, least-mean-squares (LMS), recursive least-squares (RLS) and OCTAVE vibration-control algorithms are applied to reduce the vibration. Comparing the vibration performances of the COF machine, these vibration-control algorithms are useful for reducing the vibration of the machine, which improves the service life of the machine and the quality of the forged part. Based on the vibration performances of the COF machine, the effects of LMS and RLS vibration controls are better than the OCTAVE, and they also obviously reduce the vibration of the COF machine. The vibration-control algorithms are first to be applied to reduce the vibration of the COF machines in this study, which will be beneficial to future research on the vibration controls of metal-forming machines and other mechanical systems

    Design and Simulation of Meshing Performance of Modified Straight Bevel Gears

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    As key components to transmit power and motion between intersecting shafts, it is necessary to design feasible tooth axial modification to improve the meshing performance and bearing capacity of straight bevel gears. The main purpose of this paper is to propose an effective axial modification method of straight bevel gears considering alignment errors. In this paper, the meshing performance of two kinds of tooth axial modification method (tooth end relief and symmetric crowned modification) for straight bevel gears is investigated by the finite element analysis (FEA). The results show that the tooth end relief is an optimal method to enhance the meshing performance of gears in different installations for decreasing transmission errors, reducing maximum contact stress and bending stress and improving the distribution of contact stress and bending stress. This research provides a suitable tooth end relief method of straight bevel gear with alignment errors

    Novel supercritical CO₂/organic Rankine cycle systems for solid-waste incineration energy harvesting: thermo-environmental analysis

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    Waste-to-energy is considered as an effective way to simultaneously digest the municipal waste and generate useful power. Steam Rankine cycle is conventionally adopted for solid-waste incineration energy harvesting. To further improve the energy conversion efficiency, cascade systems consisting of a supercritical CO2 cycle and an organic Rankine cycle were proposed, where both the subcritical and transcritical organic Rankine cycle systems using R1233zd(E) as the working fluid were considered. Thermodynamic and the environmental analysis were evaluated comprehensively, with a follow-up comparison with the state-of-the-art technologies. The results show that compared with the original waste-to-energy plant, the turbine output (2.55 × 107 W) and waste-to-energy efficiency (42.61%) of the supercritical CO2 cycle/subcritical organic Rankine cycle power plant are increased by 9.50 × 106 W and 59.41%, respectively. If changing to the supercritical CO2 cycle/transcritical organic Rankine cycle system, the improvement will be greater, i.e., 10.19 × 106 W and 63.71% respectively. The comparison with the state-of-the-art power plants also shows the new waste-to-energy plant has higher efficiency and better environmental performance. The ecological efficiency and sustainability index of supercritical CO2 cycle/subcritical organic Rankine cycle system power plant are 88.82% and 1.54, while 89.14% and 1.57 with the supercritical CO2 cycle/transcritical organic Rankine cycle system. The proposed cascade system demonstrated its potential in performance improvement in the field of waste-to-energy incineration. The study provides insights into the next-generation power plants for solid-waste disposal.This work was supported by the Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, Guangxi University [2020K009]
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