The major histocompatibility complex(MHC)is closely related to immune regulation.MHC shows distinct genetic polymorphism,and there are also species differences in MHC restriction.The human MHC is called human leukocyte antigen(HLA),and the mouse MHC is called H-2.The construction of humanized MHC transgenic mouse models is an important strategy to overcome the differences in MHC among species and simulate the characteristics of a human immune response.MHC transgenic mice are mainly divided into MHC Ⅰ or MHC Ⅱ single-transgenic mouse models and MHC Ⅰ and MHC Ⅱ double-transgenic mouse models.The development of HLA Ⅰ transgenic mouse model went through three stages,at present,the strategy of knocking out H-2Kb and H-2Db or murine β2m is adopted to eliminate the competitive inhibition of HLA Ⅰ molecules by endogenous H-2 class Ⅰ molecules.In the construction of an HLA Ⅱtransgenic mouse model,the β strand of murine origin is knocked out and HLA Ⅱ class genes are inserted.With the optimization of construction strategies,MHC transgenic mouse models have been applied to epitope vaccine development,tumor treatment,and genetic disease-association studies,becoming a powerful tool for preclinical trials.In this paper,we summarize the relevant data on MHC transgenic mouse models,as well as the construction strategies used for MHC transgenic mouse models and their application in vaccine development and disease treatment.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Objective:To investigate the current status and quality and safety of radiation therapy resources in medical institutions in Hunan province.Methods:The basic situation questionnaire, quality and safety self-assessment form were designed according to the content of the survey, distributed and recovered through the network, and the survey was conducted on all medical institutions (excluding military hospitals) conducting radiotherapy in Hunan province in 2022, and the quality and safety evaluation was checked by the Hunan Radiotherapy Quality Control Center using stratified sampling field inspection. The differences between the self-evaluation scores of radiotherapy quality and safety and the on-site inspection scores of each unit was compared using Wilcoxon test.Results:By the end of 2022, there were 76 medical institutions (excluding military hospitals) conducting radiotherapy in Hunan province, including 62 tertiary hospitals and 14 secondary hospitals, with a total of 44 253 radiotherapy patients admitted annually. The total number of personnel engaged in radiotherapy was 1 381, including 746 physicians, 205 physicists, 397 technicians and 33 maintenance engineers. There were a total of 88 accelerators (including 3 tomotherapy units), 10 gamma knives, and 28 rear-loading machines, with 1.33 gas pedals per million population. There were 36 units that were carrying out three-dimensional conformal technology, 60 static intensity modulation technology, 20 volumetric rotational intensity modulation, 27 stereotactic radiotherapy, 44 image-guided radiotherapy, 33 respiratory motion management, and 27 rear-loading radiotherapy. In the quality and safety evaluation situation, the basic requirements of radiotherapy specialty scored high, with 2 units achieving full marks and no failing units. Radiotherapy personnel and organization, radiotherapy process, documentation record score and other aspects of no full-score units, the score was concentrated in 60~＜80 points, and all have part of the unit failed.Conclusions:The radiotherapy industry in Hunan province has been developed steadily in recent years in general, and the structure of radiotherapy personnel tends to be reasonable, but there still exists uneven distribution of radiotherapy resources, poor utilization of equipment in some areas, and inadequate development of technology. The overall quality and safety evaluation are good, but there are still many deficiencies in the organizational requirements of radiotherapy personnel, process requirements and documentation, which need to be continuously optimized and improved in the future, and at the same time, field inspections will be intensified to ensure the quality and safety of radiotherapy.

Nanobodies derived from camelids and sharks offer unique advantages in therapeutic applications due to their ability to bind to epitopes that were previously inaccessible. Traditional methods of nanobody development face challenges such as ethical concerns and antigen toxicity. Our study presents a synthetic, phagedisplayed nanobody library using trinucleotide-directed mutagenesis technology, which allows precise amino acid composition in complementarity-determining regions (CDRs), with a focus on CDR3 diversity. This approach avoids common problems such as frameshift mutations and stop codon insertions associated with other synthetic antibody library construction methods. By analyzing FDA-approved nanobodies and Protein Data Bank sequences, we designed sub-libraries with different CDR3 lengths and introduced amino acid substitutions to improve solubility. The validation of our library through the successful isolation of nanobodies against targets such as PD-1, ATXN1 and STAT3 demonstrates a versatile and ethical platform for the development of high specificity and affinity nanobodies and represents a significant advance in biotechnology.

Nanobodies derived from camelids and sharks offer unique advantages in therapeutic applications due to their ability to bind to epitopes that were previously inaccessible. Traditional methods of nanobody development face challenges such as ethical concerns and antigen toxicity. Our study presents a synthetic, phagedisplayed nanobody library using trinucleotide-directed mutagenesis technology, which allows precise amino acid composition in complementarity-determining regions (CDRs), with a focus on CDR3 diversity. This approach avoids common problems such as frameshift mutations and stop codon insertions associated with other synthetic antibody library construction methods. By analyzing FDA-approved nanobodies and Protein Data Bank sequences, we designed sub-libraries with different CDR3 lengths and introduced amino acid substitutions to improve solubility. The validation of our library through the successful isolation of nanobodies against targets such as PD-1, ATXN1 and STAT3 demonstrates a versatile and ethical platform for the development of high specificity and affinity nanobodies and represents a significant advance in biotechnology.

Nanobodies derived from camelids and sharks offer unique advantages in therapeutic applications due to their ability to bind to epitopes that were previously inaccessible. Traditional methods of nanobody development face challenges such as ethical concerns and antigen toxicity. Our study presents a synthetic, phagedisplayed nanobody library using trinucleotide-directed mutagenesis technology, which allows precise amino acid composition in complementarity-determining regions (CDRs), with a focus on CDR3 diversity. This approach avoids common problems such as frameshift mutations and stop codon insertions associated with other synthetic antibody library construction methods. By analyzing FDA-approved nanobodies and Protein Data Bank sequences, we designed sub-libraries with different CDR3 lengths and introduced amino acid substitutions to improve solubility. The validation of our library through the successful isolation of nanobodies against targets such as PD-1, ATXN1 and STAT3 demonstrates a versatile and ethical platform for the development of high specificity and affinity nanobodies and represents a significant advance in biotechnology.

Nanobodies derived from camelids and sharks offer unique advantages in therapeutic applications due to their ability to bind to epitopes that were previously inaccessible. Traditional methods of nanobody development face challenges such as ethical concerns and antigen toxicity. Our study presents a synthetic, phagedisplayed nanobody library using trinucleotide-directed mutagenesis technology, which allows precise amino acid composition in complementarity-determining regions (CDRs), with a focus on CDR3 diversity. This approach avoids common problems such as frameshift mutations and stop codon insertions associated with other synthetic antibody library construction methods. By analyzing FDA-approved nanobodies and Protein Data Bank sequences, we designed sub-libraries with different CDR3 lengths and introduced amino acid substitutions to improve solubility. The validation of our library through the successful isolation of nanobodies against targets such as PD-1, ATXN1 and STAT3 demonstrates a versatile and ethical platform for the development of high specificity and affinity nanobodies and represents a significant advance in biotechnology.

Nanobodies derived from camelids and sharks offer unique advantages in therapeutic applications due to their ability to bind to epitopes that were previously inaccessible. Traditional methods of nanobody development face challenges such as ethical concerns and antigen toxicity. Our study presents a synthetic, phagedisplayed nanobody library using trinucleotide-directed mutagenesis technology, which allows precise amino acid composition in complementarity-determining regions (CDRs), with a focus on CDR3 diversity. This approach avoids common problems such as frameshift mutations and stop codon insertions associated with other synthetic antibody library construction methods. By analyzing FDA-approved nanobodies and Protein Data Bank sequences, we designed sub-libraries with different CDR3 lengths and introduced amino acid substitutions to improve solubility. The validation of our library through the successful isolation of nanobodies against targets such as PD-1, ATXN1 and STAT3 demonstrates a versatile and ethical platform for the development of high specificity and affinity nanobodies and represents a significant advance in biotechnology.

Objective:To understand the sleep quality and mental health status of nurses in public health emergencies, and analyze the correlation between them.Methods:A total of 128 first-line nursing staff participating in public health emergencies on February 22-23, 2020 in Tianjin Beichen Hospital, Tianjin First Central Hospital, Tianjin Fourth Central Hospital were investigated by the general data questionnaire, Pittsburgh Sleep Quality Index (PSQI), and Symptom Checklist 90 (SCL-90).Results:70.3%(90/128) of nursing staff had poor sleep quality, and the total score of PSQI was (9.71±4.01) points, which was statistically significant compared with the domestic norm ( t value was 16.479, P<0.01). The total score of SCL-90 was 1.59±0.52, which was statistically significant compared with the domestic norm ratio ( t value was 4.505, P<0.01). One-way ANOVA showed that the nursing staff's age had a significant impact on sleep quality, and the difference was statistically significant ( F value was 4.092, P<0.05). Pearson correlation analysis showed that the Pittsburgh sleep quality scale index scores and symptom self-assessment scale and somatization, force, sensitive interpersonal relationship, depression, anxiety, hostile, terrorist, paranoia, and psychosis were positively correlated( r values were 0.292-0.444, P< 0.01). Conclusions:The sleep quality and mental health status of nurses in public health emergencies are poor, and the sleep quality is correlated with mental health status.

Background: Cardiopulmonary resuscitation (CPR) strategies in COVID-19 patients differ from those in patients suffering from cardiogenic cardiac arrest. During CPR, both healthcare and non-healthcare workers who provide resuscitation are at risk of infection. The Working Group for Expert Consensus on Prevention and Cardiopulmonary Resuscitation for Cardiac Arrest in COVID-19 has developed this Chinese Expert Consensus to guide clinical practice of CPR in COVID-19 patients. Main recommendations: 1) A medical team should be assigned to evaluate severe and critical COVID-19 for early monitoring of cardiac-arrest warning signs. 2) Psychological counseling and treatment are highly recommended, since sympathetic and vagal abnormalities induced by psychological stress from the COVID-19 pandemic can induce cardiac arrest. 3) Healthcare workers should wear personal protective equipment (PPE). 4) Mouth-to-mouth ventilation should be avoided on patients suspected of having or diagnosed with COVID-19. 5) Hands-only chest compression and mechanical chest compression are recommended. 6) Tracheal-intubation procedures should be optimized and tracheal-intubation strategies should be implemented early. 7) CPR should be provided for 20-30 min. 8) Various factors should be taken into consideration such as the interests of patients and family members, ethics, transmission risks, and laws and regulations governing infectious disease control. Changes in management: The following changes or modifications to CPR strategy in COVID-19 patients are proposed: 1) Healthcare workers should wear PPE. 2) Hands-only chest compression and mechanical chest compression can be implemented to reduce or avoid the spread of viruses by aerosols. 3) Both the benefits to patients and the risk of infection should be considered. 4) Hhealthcare workers should be fully aware of and trained in CPR strategies and procedures specifically for patients with COVID-19.