With the development of ultra-wide coverage technology,multibeam echo-sounder(MBES)system has put forward higher requirements for localization accuracy and computational efficiency of ray tracing method.The classical ...With the development of ultra-wide coverage technology,multibeam echo-sounder(MBES)system has put forward higher requirements for localization accuracy and computational efficiency of ray tracing method.The classical equivalent sound speed profile(ESSP)method replaces the measured sound velocity profile(SVP)with a simple constant gradient SVP,reducing the computational workload of beam positioning.However,in deep-sea environment,the depth measurement error of this method rapidly increases from the central beam to the edge beam.By analyzing the positioning error of the ESSP method at edge beam,it is discovered that the positioning error increases monotonically with the incident angle,and the relationship between them could be expressed by polynomial function.Therefore,an error correction algorithm based on polynomial fitting is obtained.The simulation experiment conducted on an inclined seafloor shows that the proposed algorithm exhibits comparable efficiency to the original ESSP method,while significantly improving bathymetry accuracy by nearly eight times in the edge beam.展开更多
Boron neutron capture therapy(BNCT)is recognized as a precise binary targeted radiotherapy technique that effectively eliminates tumors through the^(10)B(n,α)^(7)Li nuclear reaction.Among various neutron sources,acce...Boron neutron capture therapy(BNCT)is recognized as a precise binary targeted radiotherapy technique that effectively eliminates tumors through the^(10)B(n,α)^(7)Li nuclear reaction.Among various neutron sources,accelerator-based sources have emerged as particularly promising for BNCT applications.The^(7)Li(p,n)^(7)Be reaction is highly regarded as a potential neutron source for BNCT,owing to its low threshold energy for the reaction,significant neutron yield,appropriate average neutron energy,and additional benefits.This study utilized Monte Carlo simulations to model the physical interactions within a lithium target subjected to proton bombardment,including neutron moderation by an MgF_(2)moderator and subsequent BNCT dose analysis using a Snyder head phantom.The study focused on calculating the yields of epithermal neutrons for various incident proton energies,finding an optimal energy at 2.7 MeV.Furthermore,the Snyder head phantom was employed in dose simulations to validate the effectiveness of this specific incident energy when utilizing a^(7)Li(p,n)^(7)Be neutron source for BNCT purposes.展开更多
Anti-jamming solutions based on antenna arrays enhance the anti-jamming ability and the robustness of global navigation satellite system(GNSS)receiver remarkably.However,the performance of the receiver will deteriorat...Anti-jamming solutions based on antenna arrays enhance the anti-jamming ability and the robustness of global navigation satellite system(GNSS)receiver remarkably.However,the performance of the receiver will deteriorate significantly in the overloaded interferences scenario.We define the overloaded interferences scenario as where the number of interferences is more than or equal to the number of antenna arrays elements.In this paper,the effect mechanism of interferences with different incident directions is found by studying the anti-jamming performance of the adaptive space filter.The theoretical analysis and conclusions,which are first validated through numerical examples,reveal the relationships between the optimal weight vector and the eigenvectors of the input signal autocorrelation matrix,the relationships between the interference cancellation ratio(ICR),the signal to interference and noise power ratio(SINR)of the adaptive space filter output and the number of interferences,the eigenvalues of the input signal autocorrelation matrix.In addition,two simulation experiments are utilized to further corroborate the theoretical findings through soft anti-jamming receiver.The simulation results match well with the theoretical analysis results,thus validating the effect mechanism of overloaded interferences.The simulation results show that,for a four elements circular array,the performance difference is up to 19 dB with different incident directions of interferences.Anti-jamming performance evaluation and jamming deployment optimization can obtain more accurate and efficient results by using the conclusions.展开更多
BACKGROUND:Rapid on-site triage is critical after mass-casualty incidents(MCIs)and other mass injury events.Unmanned aerial vehicles(UAVs)have been used in MCIs to search and rescue wounded individuals,but they mainly...BACKGROUND:Rapid on-site triage is critical after mass-casualty incidents(MCIs)and other mass injury events.Unmanned aerial vehicles(UAVs)have been used in MCIs to search and rescue wounded individuals,but they mainly depend on the UAV operator’s experience.We used UAVs and artificial intelligence(AI)to provide a new technique for the triage of MCIs and more efficient solutions for emergency rescue.METHODS:This was a preliminary experimental study.We developed an intelligent triage system based on two AI algorithms,namely OpenPose and YOLO.Volunteers were recruited to simulate the MCI scene and triage,combined with UAV and Fifth Generation(5G)Mobile Communication Technology real-time transmission technique,to achieve triage in the simulated MCI scene.RESULTS:Seven postures were designed and recognized to achieve brief but meaningful triage in MCIs.Eight volunteers participated in the MCI simulation scenario.The results of simulation scenarios showed that the proposed method was feasible in tasks of triage for MCIs.CONCLUSION:The proposed technique may provide an alternative technique for the triage of MCIs and is an innovative method in emergency rescue.展开更多
This study develops a procedure to rank agencies based on their incident responses using roadway clearance times for crashes. This analysis is not intended to grade agencies but to assist in identifying agencies requi...This study develops a procedure to rank agencies based on their incident responses using roadway clearance times for crashes. This analysis is not intended to grade agencies but to assist in identifying agencies requiring more training or resources for incident management. Previous NCHRP reports discussed usage of different factors including incident severity, roadway characteristics, number of lanes involved and time of incident separately for estimating the performance. However, it does not tell us how to incorporate all the factors at the same time. Thus, this study aims to account for multiple factors to ensure fair comparisons. This study used 149,174 crashes from Iowa that occurred from 2018 to 2021. A Tobit regression model was used to find the effect of different variables on roadway clearance time. Variables that cannot be controlled directly by agencies such as crash severity, roadway type, weather conditions, lighting conditions, etc., were included in the analysis as it helps to reduce bias in the ranking procedure. Then clearance time of each crash is normalized into a base condition using the regression coefficients. The normalization makes the process more efficient as the effect of uncontrollable factors has already been mitigated. Finally, the agencies were ranked by their average normalized roadway clearance time. This ranking process allows agencies to track their performance of previous crashes, can be used in identifying low performing agencies that could use additional resources and training, and can be used to identify high performing agencies to recognize for their efforts and performance.展开更多
Traffic incident management (TIM) is a FHWA Every Day Counts initiative with the objective of reducing secondary crashes, improving travel reliability, and ensuring safety of responders. Agency roadside cameras play a...Traffic incident management (TIM) is a FHWA Every Day Counts initiative with the objective of reducing secondary crashes, improving travel reliability, and ensuring safety of responders. Agency roadside cameras play a critical role in TIM by helping dispatchers quickly identify the precise location of incidents when receiving reports from motorists with varying levels of spatial accuracy. Reconciling position reports that are often mile marker based, with cameras that operate in a Pan-Tilt-Zoom coordinate system relies on dispatchers having detailed knowledge for hundreds of cameras and perhaps some presets. During real-time incident dispatching, reducing the time it takes to identify the most relevant cameras and setting their view on the incident is an important opportunity to improve incident management dispatch times. This research develops a camera-to-mile marker mapping technique that automatically sets the camera view to a specified mile marker within the field-of-view of the camera. Over 350 traffic cameras along Indiana’s 2250 directional miles of interstate were mapped to approximately 5000 discrete locations that correspond to approximately 780 directional miles (~35% of interstate) of camera coverage. This newly developed technique will allow operators to quickly identify the nearest camera and set them to the reported location. This research also identifies segments on the interstate system with limited or no camera coverage for decision makers to prioritize future capital investments. This paper concludes with brief discussion on future research to automate the mapping using LiDAR data and to set the cameras after automatically detecting the events using connected vehicle trajectory data.展开更多
Intercultural literacy is attached increasingly great importance in this interconnected world.People from diversified cultural backgrounds need to interact with each other for various purposes.Schools and organization...Intercultural literacy is attached increasingly great importance in this interconnected world.People from diversified cultural backgrounds need to interact with each other for various purposes.Schools and organizations offer courses to improve people’s intercultural competence.This paper examines two effective techniques to teach intercultural competence in the classroom setting:critical incident activity and cultural story telling.These two strategies can help achieve the desired objectives of Michael Byram’s intercultural communication model.展开更多
According to the World Health Organization’s Global Tuberculosis Report 2023,there were 10.6 million cases of tuberculosis(TB)worldwide in 2022,an increase of 2.8%over 2021,and 1.3 million people had already died of ...According to the World Health Organization’s Global Tuberculosis Report 2023,there were 10.6 million cases of tuberculosis(TB)worldwide in 2022,an increase of 2.8%over 2021,and 1.3 million people had already died of the disease.The report also indicated that approximately 748,000 new cases occurred in China in 2022,accounting for 7.1%of the global total,with an incidence of 52/100,000.展开更多
Introduction: Total knee arthroplasty (TKA) has been established as a transformative solution in the treatment of advanced degenerative diseases of the knee, such as osteoarthritis, rheumatoid arthritis, and posttraum...Introduction: Total knee arthroplasty (TKA) has been established as a transformative solution in the treatment of advanced degenerative diseases of the knee, such as osteoarthritis, rheumatoid arthritis, and posttraumatic arthritis. In this sense, TKA surgery, which seeks to replace the damaged joint with prosthetic components, has proven to be highly effective in relieving pain, improving joint function, and, ultimately, significantly increasing patients’ quality of life. The present study describes the TKA and revision knee arthroplasty (RKA) rates and, identifies the associated co morbidities in the Colombian context. Methods: A retrospective cohort study was carried out. It describes demographic and clinical characteristics between two groups of patients, TKA or RKA, and its association with mortality at 30 days, 90 days, or one year after the intervention. Results: The incidence rate of the population undergoing TKA was approximately 11.71 cases per 100,000 inhabitants. Furthermore, the incidence rate for revision knee arthroplasty (RKA) procedures in the same period was around 0.96 per 100,000 inhabitants. In both groups at 30 days postoperatively, a total mortality rate of 0.09%was recorded. When the follow-up was extended to 90 days, it increased to 0.15%;at one year postoperatively, it rose to 0.88%. Conclusion: Mortality after surgery was low in Colombia in 2019. Although RKA is a beneficial procedure, in certain circumstances, it was noted that it carries a higher risk compared to primary TKA. Our results emphasize the importance of careful evaluation of co morbidities and risk factors in patients undergoing these surgical procedures. The application of quality-of-life questionnaires should be considered in future studies on effectiveness and mortality for TKA and RKA in our country.展开更多
Biologically,because of the impact of reproduction period and nonlocal dispersal of HIV-infected cells,time delay and spatial heterogeneity should be considered.In this paper,we establish an HIV infection model with n...Biologically,because of the impact of reproduction period and nonlocal dispersal of HIV-infected cells,time delay and spatial heterogeneity should be considered.In this paper,we establish an HIV infection model with nonlocal dispersal and infection age.Moreover,applying the theory of Fourier transformation and von Foerster rule,we transform the model to an integrodifferential equation with nonlocal time delay and dispersal.The well-posedness,positivity,and boundedness of the solution for the model are studied.展开更多
The main goal of this research is to assess the impact of race, age at diagnosis, sex, and phenotype on the incidence and survivability of acute lymphocytic leukemia (ALL) among patients in the United States. By takin...The main goal of this research is to assess the impact of race, age at diagnosis, sex, and phenotype on the incidence and survivability of acute lymphocytic leukemia (ALL) among patients in the United States. By taking these factors into account, the study aims to explore how existing cancer registry data can aid in the early detection and effective treatment of ALL in patients. Our hypothesis was that statistically significant correlations exist between race, age at which patients were diagnosed, sex, and phenotype of the ALL patients, and their rate of incidence and survivability data were evaluated using SEER*Stat statistical software from National Cancer Institute. Analysis of the incidence data revealed that a higher prevalence of ALL was among the Caucasian population. The majority of ALL cases (59%) occurred in patients aged between 0 to 19 years at the time of diagnosis, and 56% of the affected individuals were male. The B-cell phenotype was predominantly associated with ALL cases (73%). When analyzing survivability data, it was observed that the 5-year survival rates slightly exceeded the 10-year survival rates for the respective demographics. Survivability rates of African Americans patients were the lowest compared to Caucasian, Asian, Pacific Islanders, Alaskan Native, Native Americans and others. Survivability rates progressively decreased for older patients. Moreover, this study investigated the typical treatment methods applied to ALL patients, mainly comprising chemotherapy, with occasional supplementation of radiation therapy as required. The study demonstrated the considerable efficacy of chemotherapy in enhancing patients’ chances of survival, while those who remained untreated faced a less favorable prognosis from the disease. Although a significant amount of data and information exists, this study can help doctors in the future by diagnosing patients with certain characteristics. It will further assist the health care professionals in screening potential patients and early detection of cases. This could also save the lives of elderly patients who have a higher mortality rate from this disease.展开更多
Objective Brain metastases significantly impact the clinical course of patients with hepatocellular carcinoma(HCC).This study aimed to examine the age-related incidence,demographics,and survival of patients with HCC a...Objective Brain metastases significantly impact the clinical course of patients with hepatocellular carcinoma(HCC).This study aimed to examine the age-related incidence,demographics,and survival of patients with HCC and brain metastases.Methods Data of HCC patients from 2010 to 2015 in the Surveillance,Epidemiology,and End Results(SEER)Registry were screened for the presence of brain metastases.They were stratified by age and ethnicity.Multivariable logistic and Cox regression analyses were used to identify factors associated with brain metastases and those with overall survival(OS)and liver cancer-specific survival(CSS),respectively.Results A total of 141 HCC patients presenting with brain metastases were identified,accounting for 0.35% of all HCC patients and 2.37% of patients with metastatic disease.Among all HCC patients,the incidence rate was the highest among patients aged 30-49 years old(0.47%).Ethnicity was not associated with the presence of brain metastases at the time of HCC diagnosis.However,African-American patients presented with a significantly lower disease-specific survival[median time:1 month;interquartile range(IQR):0-3.0 months].Initial lung or bone metastasis was independently associated with an increased risk of the presence of brain metastases[odds ratio(OR):12.62,95% confidence interval(CI):8.40-18.97]but was not associated with a worse OS or CSS among those with brain metastases.Conclusion This study identified the age-related incidence and risk factors of brain metastases in HCC patients.These results may contribute to the consideration of brain screening among patients with initial metastatic HCC with lung or bone metastases,and influence the counseling of this patient population regarding their prognosis.展开更多
Purpose: This paper aims to assess the incidences and risk factors for surgical site (ISO) infections in the general surgery department of the Koutiala District Hospital. Patients and Methods: This was a prospective a...Purpose: This paper aims to assess the incidences and risk factors for surgical site (ISO) infections in the general surgery department of the Koutiala District Hospital. Patients and Methods: This was a prospective and descriptive study from August 1, 2017 to October 31, 2020 involving all patients who underwent laparotomy in the general surgery department of the Koutiala District Hospital. Patients who were not operated on and who did not have a laparotomy were not included. Age, sex, frequency, patient history, National Nosocomial Infections Surveillance (NNIS) index, time to occur, bacteriological test results and course of infection were analyzed. Results: Fifty patients were registered. The average age was 34.2 ± 21.2 years old. Eleven patients were 60 years old or older. The hospital incidence rate was 4.3% and the community incidence rate was 6.1 cases per 100,000 population. The concept of smoking was noted in 15 patients. Patients were operated on in emergency 84% of cases. Peritonitis was the most common initial lesion with 32% of cases. Our patients had an NNIS index greater than 0 in 84% of cases. The time to develop infection from the surgical site was less than 3 days in 8 patients (16% of cases). Depending on the depth of the infection, it was superficial (cutaneous) in 39 patients (78%) and deep (subcutaneous and organic) in 11 patients (22%). Escherichia coli was the most common germ with 72% followed by staphylococcus aureus at 24%. We noted 22% morbidity. The median length of hospitalization was 9 ± 2.2 days. Conclusion: ISO is common in our service. Prevention and mastery require knowledge of risk factors.展开更多
Introduction: Like healthcare workers, medical students are also exposed to a risk of accidental contamination during their hospital internships. However, they do not benefit from prevention services in the same way a...Introduction: Like healthcare workers, medical students are also exposed to a risk of accidental contamination during their hospital internships. However, they do not benefit from prevention services in the same way as workers in this sector, although they actively participate in the routine care provided to patients in the various hospital departments. The objective of our study is to determine the incidence of these accidents and their medical and administrative management among these victims (medical students) not classified in the category of workers. Materials and Method: This was a cross-sectional study carried out over three months from January 15 to March 14, 2023. The study population consisted of all medical students at the Faculty of Health Sciences at the University of Bangui. Regularly enrolled students from 2nd to 7th year, on placement in hospitals in the Central African Republic and who gave their informed consent were included. Data were collected through a self-administered questionnaire. Results: A cross-sectional study was carried out among medical students concerning the incidence and management of accidents involving exposure to blood in the Central African Republic. Of the 254 students included, three (9%) had already been correctly vaccinated against the viral hepatitis B virus, 198 (77.9%) reported still having access to personal protective equipment, 133 students (52.4%) reported being victims of OBE in the past 12 months. The main types of OBE were stings (62%), followed by liquid splashes (32%) and cuts (6%). Among the 133 victims, 92.9% carried out immediate hand disinfection or abundant eye washing, 41.9% obtained the serology of the source patient and 37% reported the accident to their supervisor. Conclusion: It is important that students benefit from better prevention and management of these accidents.展开更多
Introduction: Acute rheumatic fever (AAR) is a non-suppurative complication of late infection by group A. Infections due to streptococci remain a public health problem in the Central African Republic. The present stud...Introduction: Acute rheumatic fever (AAR) is a non-suppurative complication of late infection by group A. Infections due to streptococci remain a public health problem in the Central African Republic. The present study aims to determine the incidence rate of AAR cases and its complications. Methodology: This was a retrospective and analytical study over a period of 4 years (from January 2015 to December 2018) at the National Laboratory of Clinical Biology and Public Health (LNBCSP) in Bangui. It focused on samples concerning the diagnosis of AAR and patient files seen in consultation in the capital’s reference health establishments. Laboratory registers and patient consultation files were used to collect data. They were entered into Excel 2010 to be analyzed with Epi Info 7. A univariate analysis by logistic regression, Ficher’s exact test, and chi<sup>2</sup> at the 5% threshold (p Results: We analyzed 94 cases meeting Jones’s criteria. The ages of the patients ranged from 18 to 85 years (mean age 52 years and mode 45 years). The incidence rate of AAR for the female sex was higher than that of the male sex during the study period (p > 0.05). It went from 166.6 in 2015 to 200 in 2016 and 2018 cases of AAR per 1000 people per year. The average incidence rate was 296.18 cases of AAR per 1000 people per year. The average incidence rate was 223.5 cases of AAR per 1000 people per year for joint damage. Joint damage represented 80.85% (RR = 0.62;Chi<sup>2</sup> = 4.88;95% CI [0.39-0.97];p Conclusion: The study allowed data on the impact rate and complications of the AAR in Bangui. Special attention to data management will help produce a complete result on the problem. Joint complications predominated. Sustaining an effective surveillance system and preventing infection would help reduce the risk of AAR occurrence.展开更多
Objective To provide reference for the news media to give play to the role of public opinion supervision in time based on the background of drug safety and social co-governance.Methods The method of case analysis was ...Objective To provide reference for the news media to give play to the role of public opinion supervision in time based on the background of drug safety and social co-governance.Methods The method of case analysis was used to make a retrospective study on the Changsheng vaccine incident in 2018.Then the role of mainstream media,pharmaceutical media,and self-media in the supervision of public opinion was investigated.Results and Conclusion Both mainstream and pharmaceutical media played an excellent role in supervising the Changchun Changsheng vaccine incident.However,the content published by some pharmaceutical media was hard to understand by ordinary people.Besides,the role of self-media in public opinion supervision was polarized.Some self-media closely kept pace with mainstream media in public opinion supervision.Other self-media unilaterally pursued the click rate,publishing false information to guide wrong public opinion.The news media should optimize the supervision efficiency of drug safety.On the one hand,pharmaceutical media should pay attention to the fact that readers may not understand the difficult terms because they are not professional.On the other hand,self-media practitioners should improve their professional quality so that they will not publish some fake news to mislead public opinion.展开更多
This commentary delves into the evolving landscape of cancer incidence and mortality in Costa Rica, presenting a comprehensive analysis of the data. Key findings reveal a concerning upward trajectory in cancer inciden...This commentary delves into the evolving landscape of cancer incidence and mortality in Costa Rica, presenting a comprehensive analysis of the data. Key findings reveal a concerning upward trajectory in cancer incidence rates, placing Costa Rica at the forefront within Central America. While prostate cancer and breast cancer dominate, disparities emerge when scrutinizing gender-specific trends. Notably, stomach and cervical cancers show declines, potentially attributed to targeted interventions. However, colorectal and liver cancers witness mortality increases, necessitating strategic responses. Geographical disparities persist across provinces, highlighting the need for equitable healthcare access. In conclusion, this commentary underscores the urgency of addressing the burgeoning cancer burden in Costa Rica, calling for evidence-based interventions and collaborative efforts on a global scale.展开更多
Lu Xun’s short stories play a prominent role in the history of modern Chinese literature,and a number of Sinologists have studied them and published their English translations.This paper selects“YīJiàn Xiǎo S...Lu Xun’s short stories play a prominent role in the history of modern Chinese literature,and a number of Sinologists have studied them and published their English translations.This paper selects“YīJiàn Xiǎo Shì”in Lu Xun’s collection“Call to Arms”as the object of study,taking hypotaxis and parataxis as the starting point,and compares the translation of Yang Hsien-yi and Gladys Yang with the original version,studying the differences between the them in the process of C-E translation.It is hoped that some flexible conversion strategies in English-Chinese translation can be learned from the translation research.展开更多
This article presents a three-dimensional analysis of the impact of the angle of incidence of the magnetic field intensity on the electrical performance (series resistance, shunt resistance) of a bifacial polycrystall...This article presents a three-dimensional analysis of the impact of the angle of incidence of the magnetic field intensity on the electrical performance (series resistance, shunt resistance) of a bifacial polycrystalline silicon solar cell. The cell is illuminated simultaneously from both sides. The continuity equation for the excess minority carriers is solved at the emitter and at the depth of the base respectively. The analytical expressions for photocurrent density, photovoltage, series resistance and shunt resistance were deduced. Using these expressions, the values of the series and shunt resistances were extracted for different values of the angle of incidence of the magnetic field intensity. The study shows that as the angle of incidence increases, the slopes of the minority carrier density for the two modes of operation of the solar cell decrease. This is explained by a drop in the accumulation of carriers in the area close to the junction due to the fact that the Lorentz force is unable to drive the carriers towards the lateral surfaces due to the weak action of the magnetic field, which tends to cancel out as the incidence angle increases, and consequently a drop in the open circuit photovoltage. This, in turn, reduces the Lorentz force. These results predict that the p-n junction of the solar cell will not heat up. The study also showed a decrease in series resistance as the incidence angle of the magnetic field intensity increased from 0 rad to π/2 rad and an increase in shunt resistance as the incidence angle increased. His behaviour of the electrical parameters when the angle of incidence of the field from 0 rad to π/2 rad shows that the decreasing magnetic field vector tends to be collinear with the electron trajectory. This allows them to cross the junction and participate in the external current. The best orientation for the Lorentz force is zero, in which case the carriers can move easily towards the junction.展开更多
The inhomogeneous sound speed in seawater causes refraction of sound waves,and the elimination of the refraction effect is essential to the accuracy of underwater acoustic positioning.The raytracing method is an indis...The inhomogeneous sound speed in seawater causes refraction of sound waves,and the elimination of the refraction effect is essential to the accuracy of underwater acoustic positioning.The raytracing method is an indispensable tool for effectively handling problems.However,this method has a conflict between localization accuracy and computational quantity.The equivalent sound speed profile(ESSP)method uses a simple sound speed profile(SSP)instead of the actual complex SSP,which can improve positioning precision but with residual error.The residual error is especially non-negligible in deep water and at large beam incidence angles.By analyzing the residual error of the ESSP method through a simulation,an empirical formula of error is presented.The data collected in the sailing circle mode(large incidence angle)of the South China Sea are used for verification.The experiments show that compared to the ESSP method,the improved algorithm has higher positioning precision and is more efficient than the ray-tracing method.展开更多
基金The Natural Science Foundation of Shandong Province of China under contract Nos ZR2022MA051 and ZR2020MA090the National Natural Science Foundation of China under contract No.U22A2012+2 种基金China Postdoctoral Science Foundation under contract No.2020M670891the SDUST Research Fund under contract No.2019TDJH103the Talent Introduction Plan for Youth Innovation Team in universities of Shandong Province(innovation team of satellite positioning and navigation)。
文摘With the development of ultra-wide coverage technology,multibeam echo-sounder(MBES)system has put forward higher requirements for localization accuracy and computational efficiency of ray tracing method.The classical equivalent sound speed profile(ESSP)method replaces the measured sound velocity profile(SVP)with a simple constant gradient SVP,reducing the computational workload of beam positioning.However,in deep-sea environment,the depth measurement error of this method rapidly increases from the central beam to the edge beam.By analyzing the positioning error of the ESSP method at edge beam,it is discovered that the positioning error increases monotonically with the incident angle,and the relationship between them could be expressed by polynomial function.Therefore,an error correction algorithm based on polynomial fitting is obtained.The simulation experiment conducted on an inclined seafloor shows that the proposed algorithm exhibits comparable efficiency to the original ESSP method,while significantly improving bathymetry accuracy by nearly eight times in the edge beam.
文摘Boron neutron capture therapy(BNCT)is recognized as a precise binary targeted radiotherapy technique that effectively eliminates tumors through the^(10)B(n,α)^(7)Li nuclear reaction.Among various neutron sources,accelerator-based sources have emerged as particularly promising for BNCT applications.The^(7)Li(p,n)^(7)Be reaction is highly regarded as a potential neutron source for BNCT,owing to its low threshold energy for the reaction,significant neutron yield,appropriate average neutron energy,and additional benefits.This study utilized Monte Carlo simulations to model the physical interactions within a lithium target subjected to proton bombardment,including neutron moderation by an MgF_(2)moderator and subsequent BNCT dose analysis using a Snyder head phantom.The study focused on calculating the yields of epithermal neutrons for various incident proton energies,finding an optimal energy at 2.7 MeV.Furthermore,the Snyder head phantom was employed in dose simulations to validate the effectiveness of this specific incident energy when utilizing a^(7)Li(p,n)^(7)Be neutron source for BNCT purposes.
基金supported by the National Natural Science Foundation of China(62003354).
文摘Anti-jamming solutions based on antenna arrays enhance the anti-jamming ability and the robustness of global navigation satellite system(GNSS)receiver remarkably.However,the performance of the receiver will deteriorate significantly in the overloaded interferences scenario.We define the overloaded interferences scenario as where the number of interferences is more than or equal to the number of antenna arrays elements.In this paper,the effect mechanism of interferences with different incident directions is found by studying the anti-jamming performance of the adaptive space filter.The theoretical analysis and conclusions,which are first validated through numerical examples,reveal the relationships between the optimal weight vector and the eigenvectors of the input signal autocorrelation matrix,the relationships between the interference cancellation ratio(ICR),the signal to interference and noise power ratio(SINR)of the adaptive space filter output and the number of interferences,the eigenvalues of the input signal autocorrelation matrix.In addition,two simulation experiments are utilized to further corroborate the theoretical findings through soft anti-jamming receiver.The simulation results match well with the theoretical analysis results,thus validating the effect mechanism of overloaded interferences.The simulation results show that,for a four elements circular array,the performance difference is up to 19 dB with different incident directions of interferences.Anti-jamming performance evaluation and jamming deployment optimization can obtain more accurate and efficient results by using the conclusions.
基金Sanming Project of Medicine in Shenzhen(No.SZSM201911007)Shenzhen Stability Support Plan(20200824145152001)。
文摘BACKGROUND:Rapid on-site triage is critical after mass-casualty incidents(MCIs)and other mass injury events.Unmanned aerial vehicles(UAVs)have been used in MCIs to search and rescue wounded individuals,but they mainly depend on the UAV operator’s experience.We used UAVs and artificial intelligence(AI)to provide a new technique for the triage of MCIs and more efficient solutions for emergency rescue.METHODS:This was a preliminary experimental study.We developed an intelligent triage system based on two AI algorithms,namely OpenPose and YOLO.Volunteers were recruited to simulate the MCI scene and triage,combined with UAV and Fifth Generation(5G)Mobile Communication Technology real-time transmission technique,to achieve triage in the simulated MCI scene.RESULTS:Seven postures were designed and recognized to achieve brief but meaningful triage in MCIs.Eight volunteers participated in the MCI simulation scenario.The results of simulation scenarios showed that the proposed method was feasible in tasks of triage for MCIs.CONCLUSION:The proposed technique may provide an alternative technique for the triage of MCIs and is an innovative method in emergency rescue.
文摘This study develops a procedure to rank agencies based on their incident responses using roadway clearance times for crashes. This analysis is not intended to grade agencies but to assist in identifying agencies requiring more training or resources for incident management. Previous NCHRP reports discussed usage of different factors including incident severity, roadway characteristics, number of lanes involved and time of incident separately for estimating the performance. However, it does not tell us how to incorporate all the factors at the same time. Thus, this study aims to account for multiple factors to ensure fair comparisons. This study used 149,174 crashes from Iowa that occurred from 2018 to 2021. A Tobit regression model was used to find the effect of different variables on roadway clearance time. Variables that cannot be controlled directly by agencies such as crash severity, roadway type, weather conditions, lighting conditions, etc., were included in the analysis as it helps to reduce bias in the ranking procedure. Then clearance time of each crash is normalized into a base condition using the regression coefficients. The normalization makes the process more efficient as the effect of uncontrollable factors has already been mitigated. Finally, the agencies were ranked by their average normalized roadway clearance time. This ranking process allows agencies to track their performance of previous crashes, can be used in identifying low performing agencies that could use additional resources and training, and can be used to identify high performing agencies to recognize for their efforts and performance.
文摘Traffic incident management (TIM) is a FHWA Every Day Counts initiative with the objective of reducing secondary crashes, improving travel reliability, and ensuring safety of responders. Agency roadside cameras play a critical role in TIM by helping dispatchers quickly identify the precise location of incidents when receiving reports from motorists with varying levels of spatial accuracy. Reconciling position reports that are often mile marker based, with cameras that operate in a Pan-Tilt-Zoom coordinate system relies on dispatchers having detailed knowledge for hundreds of cameras and perhaps some presets. During real-time incident dispatching, reducing the time it takes to identify the most relevant cameras and setting their view on the incident is an important opportunity to improve incident management dispatch times. This research develops a camera-to-mile marker mapping technique that automatically sets the camera view to a specified mile marker within the field-of-view of the camera. Over 350 traffic cameras along Indiana’s 2250 directional miles of interstate were mapped to approximately 5000 discrete locations that correspond to approximately 780 directional miles (~35% of interstate) of camera coverage. This newly developed technique will allow operators to quickly identify the nearest camera and set them to the reported location. This research also identifies segments on the interstate system with limited or no camera coverage for decision makers to prioritize future capital investments. This paper concludes with brief discussion on future research to automate the mapping using LiDAR data and to set the cameras after automatically detecting the events using connected vehicle trajectory data.
文摘Intercultural literacy is attached increasingly great importance in this interconnected world.People from diversified cultural backgrounds need to interact with each other for various purposes.Schools and organizations offer courses to improve people’s intercultural competence.This paper examines two effective techniques to teach intercultural competence in the classroom setting:critical incident activity and cultural story telling.These two strategies can help achieve the desired objectives of Michael Byram’s intercultural communication model.
基金supported by grants from Research Fund for Key Research and Development Project in Hainan,ZDYF2021GXJS018Research Foundation for Advanced Talents of Hainan [No.820RC649]Prevention and Control of Hepatitis B in China [No.YGFK20200090]
文摘According to the World Health Organization’s Global Tuberculosis Report 2023,there were 10.6 million cases of tuberculosis(TB)worldwide in 2022,an increase of 2.8%over 2021,and 1.3 million people had already died of the disease.The report also indicated that approximately 748,000 new cases occurred in China in 2022,accounting for 7.1%of the global total,with an incidence of 52/100,000.
文摘Introduction: Total knee arthroplasty (TKA) has been established as a transformative solution in the treatment of advanced degenerative diseases of the knee, such as osteoarthritis, rheumatoid arthritis, and posttraumatic arthritis. In this sense, TKA surgery, which seeks to replace the damaged joint with prosthetic components, has proven to be highly effective in relieving pain, improving joint function, and, ultimately, significantly increasing patients’ quality of life. The present study describes the TKA and revision knee arthroplasty (RKA) rates and, identifies the associated co morbidities in the Colombian context. Methods: A retrospective cohort study was carried out. It describes demographic and clinical characteristics between two groups of patients, TKA or RKA, and its association with mortality at 30 days, 90 days, or one year after the intervention. Results: The incidence rate of the population undergoing TKA was approximately 11.71 cases per 100,000 inhabitants. Furthermore, the incidence rate for revision knee arthroplasty (RKA) procedures in the same period was around 0.96 per 100,000 inhabitants. In both groups at 30 days postoperatively, a total mortality rate of 0.09%was recorded. When the follow-up was extended to 90 days, it increased to 0.15%;at one year postoperatively, it rose to 0.88%. Conclusion: Mortality after surgery was low in Colombia in 2019. Although RKA is a beneficial procedure, in certain circumstances, it was noted that it carries a higher risk compared to primary TKA. Our results emphasize the importance of careful evaluation of co morbidities and risk factors in patients undergoing these surgical procedures. The application of quality-of-life questionnaires should be considered in future studies on effectiveness and mortality for TKA and RKA in our country.
基金Supported by Funding for the National Natural Science Foundation of China(12201557,12001483,61807006)。
文摘Biologically,because of the impact of reproduction period and nonlocal dispersal of HIV-infected cells,time delay and spatial heterogeneity should be considered.In this paper,we establish an HIV infection model with nonlocal dispersal and infection age.Moreover,applying the theory of Fourier transformation and von Foerster rule,we transform the model to an integrodifferential equation with nonlocal time delay and dispersal.The well-posedness,positivity,and boundedness of the solution for the model are studied.
文摘The main goal of this research is to assess the impact of race, age at diagnosis, sex, and phenotype on the incidence and survivability of acute lymphocytic leukemia (ALL) among patients in the United States. By taking these factors into account, the study aims to explore how existing cancer registry data can aid in the early detection and effective treatment of ALL in patients. Our hypothesis was that statistically significant correlations exist between race, age at which patients were diagnosed, sex, and phenotype of the ALL patients, and their rate of incidence and survivability data were evaluated using SEER*Stat statistical software from National Cancer Institute. Analysis of the incidence data revealed that a higher prevalence of ALL was among the Caucasian population. The majority of ALL cases (59%) occurred in patients aged between 0 to 19 years at the time of diagnosis, and 56% of the affected individuals were male. The B-cell phenotype was predominantly associated with ALL cases (73%). When analyzing survivability data, it was observed that the 5-year survival rates slightly exceeded the 10-year survival rates for the respective demographics. Survivability rates of African Americans patients were the lowest compared to Caucasian, Asian, Pacific Islanders, Alaskan Native, Native Americans and others. Survivability rates progressively decreased for older patients. Moreover, this study investigated the typical treatment methods applied to ALL patients, mainly comprising chemotherapy, with occasional supplementation of radiation therapy as required. The study demonstrated the considerable efficacy of chemotherapy in enhancing patients’ chances of survival, while those who remained untreated faced a less favorable prognosis from the disease. Although a significant amount of data and information exists, this study can help doctors in the future by diagnosing patients with certain characteristics. It will further assist the health care professionals in screening potential patients and early detection of cases. This could also save the lives of elderly patients who have a higher mortality rate from this disease.
文摘Objective Brain metastases significantly impact the clinical course of patients with hepatocellular carcinoma(HCC).This study aimed to examine the age-related incidence,demographics,and survival of patients with HCC and brain metastases.Methods Data of HCC patients from 2010 to 2015 in the Surveillance,Epidemiology,and End Results(SEER)Registry were screened for the presence of brain metastases.They were stratified by age and ethnicity.Multivariable logistic and Cox regression analyses were used to identify factors associated with brain metastases and those with overall survival(OS)and liver cancer-specific survival(CSS),respectively.Results A total of 141 HCC patients presenting with brain metastases were identified,accounting for 0.35% of all HCC patients and 2.37% of patients with metastatic disease.Among all HCC patients,the incidence rate was the highest among patients aged 30-49 years old(0.47%).Ethnicity was not associated with the presence of brain metastases at the time of HCC diagnosis.However,African-American patients presented with a significantly lower disease-specific survival[median time:1 month;interquartile range(IQR):0-3.0 months].Initial lung or bone metastasis was independently associated with an increased risk of the presence of brain metastases[odds ratio(OR):12.62,95% confidence interval(CI):8.40-18.97]but was not associated with a worse OS or CSS among those with brain metastases.Conclusion This study identified the age-related incidence and risk factors of brain metastases in HCC patients.These results may contribute to the consideration of brain screening among patients with initial metastatic HCC with lung or bone metastases,and influence the counseling of this patient population regarding their prognosis.
文摘Purpose: This paper aims to assess the incidences and risk factors for surgical site (ISO) infections in the general surgery department of the Koutiala District Hospital. Patients and Methods: This was a prospective and descriptive study from August 1, 2017 to October 31, 2020 involving all patients who underwent laparotomy in the general surgery department of the Koutiala District Hospital. Patients who were not operated on and who did not have a laparotomy were not included. Age, sex, frequency, patient history, National Nosocomial Infections Surveillance (NNIS) index, time to occur, bacteriological test results and course of infection were analyzed. Results: Fifty patients were registered. The average age was 34.2 ± 21.2 years old. Eleven patients were 60 years old or older. The hospital incidence rate was 4.3% and the community incidence rate was 6.1 cases per 100,000 population. The concept of smoking was noted in 15 patients. Patients were operated on in emergency 84% of cases. Peritonitis was the most common initial lesion with 32% of cases. Our patients had an NNIS index greater than 0 in 84% of cases. The time to develop infection from the surgical site was less than 3 days in 8 patients (16% of cases). Depending on the depth of the infection, it was superficial (cutaneous) in 39 patients (78%) and deep (subcutaneous and organic) in 11 patients (22%). Escherichia coli was the most common germ with 72% followed by staphylococcus aureus at 24%. We noted 22% morbidity. The median length of hospitalization was 9 ± 2.2 days. Conclusion: ISO is common in our service. Prevention and mastery require knowledge of risk factors.
文摘Introduction: Like healthcare workers, medical students are also exposed to a risk of accidental contamination during their hospital internships. However, they do not benefit from prevention services in the same way as workers in this sector, although they actively participate in the routine care provided to patients in the various hospital departments. The objective of our study is to determine the incidence of these accidents and their medical and administrative management among these victims (medical students) not classified in the category of workers. Materials and Method: This was a cross-sectional study carried out over three months from January 15 to March 14, 2023. The study population consisted of all medical students at the Faculty of Health Sciences at the University of Bangui. Regularly enrolled students from 2nd to 7th year, on placement in hospitals in the Central African Republic and who gave their informed consent were included. Data were collected through a self-administered questionnaire. Results: A cross-sectional study was carried out among medical students concerning the incidence and management of accidents involving exposure to blood in the Central African Republic. Of the 254 students included, three (9%) had already been correctly vaccinated against the viral hepatitis B virus, 198 (77.9%) reported still having access to personal protective equipment, 133 students (52.4%) reported being victims of OBE in the past 12 months. The main types of OBE were stings (62%), followed by liquid splashes (32%) and cuts (6%). Among the 133 victims, 92.9% carried out immediate hand disinfection or abundant eye washing, 41.9% obtained the serology of the source patient and 37% reported the accident to their supervisor. Conclusion: It is important that students benefit from better prevention and management of these accidents.
文摘Introduction: Acute rheumatic fever (AAR) is a non-suppurative complication of late infection by group A. Infections due to streptococci remain a public health problem in the Central African Republic. The present study aims to determine the incidence rate of AAR cases and its complications. Methodology: This was a retrospective and analytical study over a period of 4 years (from January 2015 to December 2018) at the National Laboratory of Clinical Biology and Public Health (LNBCSP) in Bangui. It focused on samples concerning the diagnosis of AAR and patient files seen in consultation in the capital’s reference health establishments. Laboratory registers and patient consultation files were used to collect data. They were entered into Excel 2010 to be analyzed with Epi Info 7. A univariate analysis by logistic regression, Ficher’s exact test, and chi<sup>2</sup> at the 5% threshold (p Results: We analyzed 94 cases meeting Jones’s criteria. The ages of the patients ranged from 18 to 85 years (mean age 52 years and mode 45 years). The incidence rate of AAR for the female sex was higher than that of the male sex during the study period (p > 0.05). It went from 166.6 in 2015 to 200 in 2016 and 2018 cases of AAR per 1000 people per year. The average incidence rate was 296.18 cases of AAR per 1000 people per year. The average incidence rate was 223.5 cases of AAR per 1000 people per year for joint damage. Joint damage represented 80.85% (RR = 0.62;Chi<sup>2</sup> = 4.88;95% CI [0.39-0.97];p Conclusion: The study allowed data on the impact rate and complications of the AAR in Bangui. Special attention to data management will help produce a complete result on the problem. Joint complications predominated. Sustaining an effective surveillance system and preventing infection would help reduce the risk of AAR occurrence.
文摘Objective To provide reference for the news media to give play to the role of public opinion supervision in time based on the background of drug safety and social co-governance.Methods The method of case analysis was used to make a retrospective study on the Changsheng vaccine incident in 2018.Then the role of mainstream media,pharmaceutical media,and self-media in the supervision of public opinion was investigated.Results and Conclusion Both mainstream and pharmaceutical media played an excellent role in supervising the Changchun Changsheng vaccine incident.However,the content published by some pharmaceutical media was hard to understand by ordinary people.Besides,the role of self-media in public opinion supervision was polarized.Some self-media closely kept pace with mainstream media in public opinion supervision.Other self-media unilaterally pursued the click rate,publishing false information to guide wrong public opinion.The news media should optimize the supervision efficiency of drug safety.On the one hand,pharmaceutical media should pay attention to the fact that readers may not understand the difficult terms because they are not professional.On the other hand,self-media practitioners should improve their professional quality so that they will not publish some fake news to mislead public opinion.
文摘This commentary delves into the evolving landscape of cancer incidence and mortality in Costa Rica, presenting a comprehensive analysis of the data. Key findings reveal a concerning upward trajectory in cancer incidence rates, placing Costa Rica at the forefront within Central America. While prostate cancer and breast cancer dominate, disparities emerge when scrutinizing gender-specific trends. Notably, stomach and cervical cancers show declines, potentially attributed to targeted interventions. However, colorectal and liver cancers witness mortality increases, necessitating strategic responses. Geographical disparities persist across provinces, highlighting the need for equitable healthcare access. In conclusion, this commentary underscores the urgency of addressing the burgeoning cancer burden in Costa Rica, calling for evidence-based interventions and collaborative efforts on a global scale.
基金The paper is part of the achievements of“Research of the English Translation of Lu Xun’s Short Stories and Their Dissemination”(鲁迅小说英译及传播研究),a Shanghai City College Students’project in 2023.Its serial number is SH2023141.
文摘Lu Xun’s short stories play a prominent role in the history of modern Chinese literature,and a number of Sinologists have studied them and published their English translations.This paper selects“YīJiàn Xiǎo Shì”in Lu Xun’s collection“Call to Arms”as the object of study,taking hypotaxis and parataxis as the starting point,and compares the translation of Yang Hsien-yi and Gladys Yang with the original version,studying the differences between the them in the process of C-E translation.It is hoped that some flexible conversion strategies in English-Chinese translation can be learned from the translation research.
文摘This article presents a three-dimensional analysis of the impact of the angle of incidence of the magnetic field intensity on the electrical performance (series resistance, shunt resistance) of a bifacial polycrystalline silicon solar cell. The cell is illuminated simultaneously from both sides. The continuity equation for the excess minority carriers is solved at the emitter and at the depth of the base respectively. The analytical expressions for photocurrent density, photovoltage, series resistance and shunt resistance were deduced. Using these expressions, the values of the series and shunt resistances were extracted for different values of the angle of incidence of the magnetic field intensity. The study shows that as the angle of incidence increases, the slopes of the minority carrier density for the two modes of operation of the solar cell decrease. This is explained by a drop in the accumulation of carriers in the area close to the junction due to the fact that the Lorentz force is unable to drive the carriers towards the lateral surfaces due to the weak action of the magnetic field, which tends to cancel out as the incidence angle increases, and consequently a drop in the open circuit photovoltage. This, in turn, reduces the Lorentz force. These results predict that the p-n junction of the solar cell will not heat up. The study also showed a decrease in series resistance as the incidence angle of the magnetic field intensity increased from 0 rad to π/2 rad and an increase in shunt resistance as the incidence angle increased. His behaviour of the electrical parameters when the angle of incidence of the field from 0 rad to π/2 rad shows that the decreasing magnetic field vector tends to be collinear with the electron trajectory. This allows them to cross the junction and participate in the external current. The best orientation for the Lorentz force is zero, in which case the carriers can move easily towards the junction.
基金the Natural Science Foundation of Shandong Province of China(No.ZR2022MA051)the China Postdoctoral Science Foundation(No.2020M670891)the SDUST Research Fund(No.2019TDJH103)。
文摘The inhomogeneous sound speed in seawater causes refraction of sound waves,and the elimination of the refraction effect is essential to the accuracy of underwater acoustic positioning.The raytracing method is an indispensable tool for effectively handling problems.However,this method has a conflict between localization accuracy and computational quantity.The equivalent sound speed profile(ESSP)method uses a simple sound speed profile(SSP)instead of the actual complex SSP,which can improve positioning precision but with residual error.The residual error is especially non-negligible in deep water and at large beam incidence angles.By analyzing the residual error of the ESSP method through a simulation,an empirical formula of error is presented.The data collected in the sailing circle mode(large incidence angle)of the South China Sea are used for verification.The experiments show that compared to the ESSP method,the improved algorithm has higher positioning precision and is more efficient than the ray-tracing method.