Natural killer cells(NK)are important innate immune cells that do not require prior antigen exposure and can directly recognize and attack virus-infected cells and tumor cells.The activation and effector functions of NK cells are regulated by a balance of signals delivered through their surface activating receptors and inhibitory re-ceptors,which bind to ligands on target cells to achieve cytotoxicity via"induced self"and"missing self"recogni-tion models.The killing mechanisms of NK cells primarily include release of cytotoxic granules such as perforin and granzymes to induce target cell lysis,death receptor-mediated apoptosis,secretion of various cytokines,chemokines and growth factors to coordinate with other immune cells in killing tumor cells,thereby generating secondary im-mune responses and antibody-dependent cellular cytotoxicity(ADCC).

Tibetan sheep,the main domestic animal raised in the Qinghai-Tibet Plateau region,are a source of human plague transmission.In the Qinghai-Tibet Plateau region,Tibetan sheep are considered valuable breeding resources,because of their large body size and high adaptability to high-altitude environments.In recent years,many pastoral areas,particularly those with marmot plague sources,have improved the structure of sheep breeds through pure breeding of Tibetan sheep or hybridization with Tibetan sheep to improve breed quality.The scale of breeding of Tibetan sheep or hybrid sheep is increasing,and their participation in the spread of plague poses a severe challenge to plague prevention and control.This article provides a comprehensive review of the current status of Tibetan sheep plague and related research progress,to provide a theoretical basis for further exploration and research on plague infection and transmission in Tibetan sheep and hybrid sheep.The findings will be critical for conducting risk assessment of Ti-betan sheep plague in marmot plague source areas,enhancing monitoring and early warning capabilities,formulating and implement-ing risk control measures,and strictly preventing the occurrence and spread of human plague.

In order to promote the construction of a multi-point trigger intelligent surveillance and early warning system of the plague in China, the development process, application practice, advantages, and limitations of the plague surveillance and early warning system in China and its role in plague prevention and control are reviewed and analyzed. It is suggested to include multiple departments, carry out a multi-channel monitoring mechanism for plague from different perspectives, further improve the plague surveillance and early warning system, and enhance surveillance and early warning capability.

The discovery of streptomycin in 1943 marked a new era in plague treatment. Over the subsequent eight decades, significant advances have been made through the implementation of various antibiotics, both as monotherapy and in combination regimens. These treatments have included aminoglycosides (such as streptomycin and gentamicin), tetracyclines, sulfonamides, chloramphenicol, quinolones, and beta-lactams, which have dramatically cut down the death rate from plague infections. However, due to bacterial adaptation mechanisms, Yersinia pestis can develop diminished sensitivity or resistance to certain antibiotics. This article examines the resistance mechanisms of Yersinia pestis and analyzes antimicrobial susceptibility patterns and resistance in plague treatment, aiming to provide scientific evidence for clinicians to understand the current status of traditional and new antibiotics in plague treatment and improve the treatment level of plague patients.

Tibetan sheep,the main domestic animal raised in the Qinghai-Tibet Plateau region,are a source of human plague transmission.In the Qinghai-Tibet Plateau region,Tibetan sheep are considered valuable breeding resources,because of their large body size and high adaptability to high-altitude environments.In recent years,many pastoral areas,particularly those with marmot plague sources,have improved the structure of sheep breeds through pure breeding of Tibetan sheep or hybridization with Tibetan sheep to improve breed quality.The scale of breeding of Tibetan sheep or hybrid sheep is increasing,and their participation in the spread of plague poses a severe challenge to plague prevention and control.This article provides a comprehensive review of the current status of Tibetan sheep plague and related research progress,to provide a theoretical basis for further exploration and research on plague infection and transmission in Tibetan sheep and hybrid sheep.The findings will be critical for conducting risk assessment of Ti-betan sheep plague in marmot plague source areas,enhancing monitoring and early warning capabilities,formulating and implement-ing risk control measures,and strictly preventing the occurrence and spread of human plague.

The plague is a infectious disease of natural focus. The occurrence of animal plague is a complex biological phenomenon, which is affected by many factors such as hosts, vectors, geographical landscapes, climate, human activities and so on. Its epidemiological patterns exhibit spatial and temporal characteristics. Therefore, the plague monitoring and early warning has always been the key to plague prevention and control, and remains a current research hotspot. In recent years, with the advancement of spatial epidemiology technology, it has been increasingly applied in plague prevention and control, and has made remarkable achievements in exploring the spatio-temporal relationships, influencing factors, monitoring and early warning of the plague. This article provides an overview of specific applications of spatial epidemiological methods in four areas, including spatial visualization of plague outbreaks, aggregation analysis, exploration of influencing factors, risk prediction and early warning. It aims to offer insights for the plague prevention and control personnel to better understand the suddenness and complexity of the plague from the perspective of spatial epidemiology, to uncover the epidemiological patterns of the plague, and to provide a reference for precise plague prevention and control.

The plague is a infectious disease of natural focus. The occurrence of animal plague is a complex biological phenomenon, which is affected by many factors such as hosts, vectors, geographical landscapes, climate, human activities and so on. Its epidemiological patterns exhibit spatial and temporal characteristics. Therefore, the plague monitoring and early warning has always been the key to plague prevention and control, and remains a current research hotspot. In recent years, with the advancement of spatial epidemiology technology, it has been increasingly applied in plague prevention and control, and has made remarkable achievements in exploring the spatio-temporal relationships, influencing factors, monitoring and early warning of the plague. This article provides an overview of specific applications of spatial epidemiological methods in four areas, including spatial visualization of plague outbreaks, aggregation analysis, exploration of influencing factors, risk prediction and early warning. It aims to offer insights for the plague prevention and control personnel to better understand the suddenness and complexity of the plague from the perspective of spatial epidemiology, to uncover the epidemiological patterns of the plague, and to provide a reference for precise plague prevention and control.

In order to promote the construction of a multi-point trigger intelligent surveillance and early warning system of the plague in China, the development process, application practice, advantages, and limitations of the plague surveillance and early warning system in China and its role in plague prevention and control are reviewed and analyzed. It is suggested to include multiple departments, carry out a multi-channel monitoring mechanism for plague from different perspectives, further improve the plague surveillance and early warning system, and enhance surveillance and early warning capability.

The discovery of streptomycin in 1943 marked a new era in plague treatment. Over the subsequent eight decades, significant advances have been made through the implementation of various antibiotics, both as monotherapy and in combination regimens. These treatments have included aminoglycosides (such as streptomycin and gentamicin), tetracyclines, sulfonamides, chloramphenicol, quinolones, and beta-lactams, which have dramatically cut down the death rate from plague infections. However, due to bacterial adaptation mechanisms, Yersinia pestis can develop diminished sensitivity or resistance to certain antibiotics. This article examines the resistance mechanisms of Yersinia pestis and analyzes antimicrobial susceptibility patterns and resistance in plague treatment, aiming to provide scientific evidence for clinicians to understand the current status of traditional and new antibiotics in plague treatment and improve the treatment level of plague patients.

Objective:To analyze the monitoring results of human brucellosis prevention and control project in Gansu Province, in order to provide reference for the next revision of prevention and control plans.Methods:The data from the "China Disease Prevention and Control Information System" in Gansu Province from 2016 to 2022 and the annual data of human brucellosis cases reported by the active monitoring reports in various project counties (districts) were input into Excel 2016 software and a database was established. The epidemiological situation of brucellosis, the coverage of brucellosis prevention and control projects, the number of detected cases and health education were analyzed and compared by descriptive epidemiological method.Results:From 2016 to 2022, 70 to 82 out of 86 counties (districts) in Gansu Province were found to have human outbreaks of brucellosis, with brucellosis prevention and control projects covering 17 to 43 counties (districts). A total of 19 855 cases of human brucellosis were reported online in the province, with an average annual incidence of 11.07/100 000 and an annual incidence ranging from 6.03/100 000 to 20.89/100 000. There was a statistically significant difference in incidence among years (χ 2 = 5 264.84, P < 0.001). Through active monitoring, a total of 433 303 cases of brucellosis (tiger red plate agglutination test, RBT) were initially screened in project counties (districts) throughout the province, with 13 277 positive cases and a positive rate of 3.06% (13 277/433 303). Then the laboratory confirmed test (test-tube agglutination test, SAT) for brucellosis was carried out, with 9 967 positive cases and a positive rate of 2.30% (9 967/433 303). The infection rate of brucellosis in the population (SAT positive) was compared between different years, and the difference was statistically significant (χ 2 = 600.12, P < 0.001). In the project counties (districts), 7 481 confirmed cases of brucellosis were detected by active surveillance, and 15 794 cases were reported online, accounting for 47.37% (7 481/15 794) of the total number of cases reported online. The average awareness rate of brucellosis knowledge among medical personnel increased from 70.49% before training to 88.89% after training. The average awareness rate of brucellosis prevention and control knowledge among high-risk groups increased from 63.49% before health education to 89.05% after health education, and the behavior formation rate increased from 62.84% to 86.04%. Conclusions:From 2016 to 2022, the epidemic scope of human brucellosis in Gansu Province has been expanding year by year, and the coverage of prevention and control project is relatively small. The proportion of cases detected through active screening is relatively low. It is necessary to increase special funding investment, expand project coverage, strengthen high-risk group screening, education and behavioral intervention, and follow-up management of acute stage patient, so as to identify patients as early as possible and curb the upward trend of the epidemic.