Objective:To understand the molecular characteristics of the mutant strain of polymerase basic protein 2 (PB2) gene of influenza A (H1N1pdm) in Guangdong province, and to explore its specific molecular sites, so as to provide scientific basis for the prevention and control of influenza virus.Methods:Throat swab samples were collected from 2 cases infected with PB2 gene variant strains for virus isolation, and 23 influenza virus strains were selected from Guangdong province for sequencing analysis. The reference sequences and vaccine strain sequences provided by GISAID were used to perform evolutionary analysis on hemagglutinin (HA) and PB2 genes. Virus strain antigen analysis and neuraminidase (NA) inhibition test were carried out. PB2 protein model was constructed and polymerase activity was analyzed.Results:H399N amino acid mutation occurred in the HA gene of PB2-D701N and PB2-A271S variant strains, both of which belonged to the branch of 6B.1A.5a.2a. They belonged to the same big branch and different small branches as the vaccine strain A/Victoria/4897/2022, and they are all vaccine-like strains. In the three-dimensional structure, the mutations of PB2-D701N and PB2-A271S change charge and hydrophobicity.Conclusions:PB2-D701 and A271 were highly conserved, and PB2 mutant strains were not the dominant strains. The PB2 mutant had high antigenicity with the vaccine. The PB2 mutant strain is sensitive to NA inhibitors. The three-dimensional model predicted that PB2-D701N mutation could enhance virulence and affect transmissibility of influenza virus, while PB2-A271S mutation could affect polymerase activity and polymerase complex synthesis of influenza virus.

Objective:To develop and validate a risk prediction model for cognitive frailty in elderly patients with type 2 diabetes.Methods:A total of 483 elderly patients with type 2 diabetes who visited Tianjin First Central Hospital from June to December 2022 were selected using convenience sampling. They were randomly divided into a modeling group ( n=338) and a validation group ( n=145). Data were collected using a self-designed general information questionnaire, the Short-Form Mini Nutritional Assessment (MNA-SF), the Geriatric Depression Scale-15 (GDS-15), the Frailty Phenotype (FP), the Montreal Cognitive Assessment (MoCA), and the Clinical Dementia Rating (CDR). Logistic regression analysis was performed to identify the influencing factors. A cognitive frailty risk prediction nomogram model was constructed based on the results. The model was validated in the validation group, and its predictive performance and clinical applicability were evaluated using the area under the receiver operating characteristic curve ( AUC), calibration curve, and clinical decision curve analysis. A total of 483 questionnaires were distributed and all were returned as valid, resulting in a 100.0% response rate. Results:The prevalence of cognitive frailty in the 483 elderly patients with type 2 diabetes was 20.3% (98/483). Age, regular exercise, duration of diabetes, HbA1c levels, depression and nutritional status were identified as predictive factors in the model. The AUC of the model was 0.886, and the Hosmer-Lemeshow test showed a χ 2 value of 8.004 ( P=0.433). The optimal cutoff value was 0.335, and the accuracy was 89.0%. Conclusions:The prediction model demonstrates good fit and strong predictive performance, and can intuitively and easily identify elderly patients with type 2 diabetes who are at high risk of cognitive frailty, providing a reference for early screening and intervention.

Objective:To select and obtain evidence on oral health management for dementia patients, and summarize the best evidence.Methods:The best clinical practices, guidelines, expert consensus, evidence summary, recommended practices, and systematic reviews on oral health management for patients with dementia and cognitive impairment were electronically retrieved from British Medical Journal Best Practice, Australia Joanna Briggs Institute Evidence-Based Health Care Center Database, Agency for Healthcare Research and Quality, and National Institute for Health and Clinical Excellence, Cochrane Library, PubMed, Alzheimer's Association, China Biomedical Database, China National Knowledge Infrastructure, WanFang Data and VIP and so on. The search period was from database establishment to October 31, 2023. Two to four researchers evaluated the quality of the included literature and extracted evidence from the literature that met the quality standards.Results:A total of 11 articles were included, including two guidelines, five evidence summaries, one recommended practice, and three systematic reviews. A total of 31 best pieces of evidence were summarized from eight aspects, including team work, personnel training, oral assessment, oral cleaning procedures, denture management, communication and behavior management, interventions for special oral problems, and health education.Conclusions:The oral health management of dementia patients has its particularity and the incidence of oral complications is high. It is necessary to strengthen the awareness and training of medical and nursing staff, pay attention to oral assessment, oral care, and communication skills, actively prevent and handle special oral problems, so as to improve the oral health of patients. In addition, it is recommended to evaluate patient cultural differences, clinical environment of the medical institution, patient willingness and so on before applying evidence in clinical practice, and then implement targeted evidence measures.

Based on the analysis of heart rate variability(HRV),a prediction method for paroxysmal atrial fibrillation(PAF)attacks is proposed.A new adaptive filtering technique is used for smoothing and coarse graining of HRV,followed by entropy-based quantification of HRV complexity at multiple adaptive scales.After the features are normalized by Min-Max,feature subsets are selected by sequential forward selection method,and then input to support vector machine to identify HRV types and predict PAF attacks.Through 5-fold cross-validation on a set of 50 HRV sequences each lasting 5 minutes,the optimal prediction results are obtained:98%accuracy,100%sensitivity,96%specificity,demonstrating excellent performance.In addition,the experiment shows significant changes(P<0.05)in the complexity eigenvalues of HRV far away from and close to PAF at different frequency bands,reflecting alterations in nervous system regulation of cardiac rhythm and a decline in the ability to adapt to external environmental changes such as stress regulation.

Objective To propose a regression tree model for the estimation of blood pressure using the minimalist characteristics of photoplethysmography(PPG)signals.Methods Fifteen characteristic parameters were extracted from the PPG signals,and the 4 parameters with the highest correlations with blood pressure were screened using the Spearman correlation coefficient to construct a regression tree model for blood pressure estimation using the minimalist characteristics.Results The estimation errors of systolic and diastolic blood pressures in the constructed model were(-0.02±3.63)mmHg and(-0.04±2.10)mmHg,respectively.Conclusion The proposed regression tree model has a simple structure and high accuracy,which is of great significance for using a single-channel PPG signal for blood pressure estimation in wearable devices.

Objective:To evaluate the impact of self-crosslinked hyaluronic acid (SCH) gel on endometrium recovery after artificial abortion.Methods:A multicenter, prospective randomized controlled trial was conducted across 18 hospitals from December 2021 to February 2023, involving 382 women who underwent artificial abortion. Participants were randomly allocated to receive either treatment with SCH gel (SCH group) or no treatment (control group) in a 1∶1 ratio. The primary outcome was endometrium thickness in 14 to 18 days after the first postoperative menstruation. Secondary outcomes included changes in menstrual volume during the first postoperative menstruation, menstruation resumption within 6 postoperative weeks, time to menstruation resumption, duration of the first postoperative menstruation, and incidence of dysmenorrhea.Results:Baseline characteristics of participants were comparable between the two groups (all P>0.05), with 95.3% (182/191) in SCH group and 92.7% (177/191) in the control group completed the study. The postoperative endometrial thickness in SCH group was significantly greater than that in the control group [(9.78±3.15) vs (8.95±2.32) mm; P=0.005]. SCH group also had significantly fewer participants with reduced menstrual volume [23 cases (12.6%, 23/182) vs 31 cases (17.5%, 31/177); P=0.038]. Although SCH group experienced less dysmenorrhea during the first postoperative menstrual period, this difference was not statistically significant [28.5% (51/179) vs 37.1% (65/175); P=0.083]. Outcomes were similar between SCH group and the control group regarding the proportion of participants who resumed menstruation within 6 weeks postoperatively, time to menstruation resumption, and duration of the first postoperative menstruation ( P=0.792, 0.485, and 0.254, respectively). No serious adverse events were observed during the study period, and no adverse events were attributed to SCH gel treatment. Conclusion:The application of SCH gel after artificial abortion is safe and might aid in the recovery of the endometrium.

Objective:To perform FLASH irradiation experiments on cells and animals with carbon ion beams by updating the beam conditions and testing the performance of a clinical carbon ion therapy system.Methods:By using the vertical beam of the carbon ion therapy system and shortening the synchrotron beam extraction time to increase the current intensity, ultra-high dose rate beam could be achieved. Spreading the high current beam in the depth direction using a ridge filter and expanding it horizontally using point scanning technology could form the required field for cellular and animal experiments. The field flatness, penumbra, absorbed dose, average dose rate and other parameters were measured to verify whether the beam performance met the requirements.Results:The spread-out Bragg peak in the depth direction was consistent with the design, and the parameters such as field flatness and penumbra obtained by the measured lateral dose curve met the experimental requirements. After expansion, within a target volume of 20 mm×20 mm×10 mm, the absorbed dose in the field reaches 8 Gy, with the equivalent field dose rate of over 60 Gy/s and the maximum could reach 100 Gy/s. Within a target volume of 30 mm×30 mm×10 mm, the absorbed dose in the field is 4 Gy, and the equivalent filed dose rate of some energy in the field is greater than 40 Gy/s. In the experiment, the energy with a suitable dose rate can be selected for irradiation.Conclusion:After beam optimization, the carbon ion FLASH irradiation conditions for cytology and animal experiments can be realized on synchrotrons, and the beam performance parameters can meet the experimental requirements.

Objective:To investigate the treatment strategy and prognostic factors of nasopharyngeal necrosis after the first radical radiotherapy for nasopharyngeal carcinoma.Methods:Clinical data of 1020 patients with nasopharyngeal carcinoma undergoing radical intensity-modulated radiotherapy in Jiangsu Cancer Hospital from January 2013 to January 2022 were retrospectively analyzed. Nasopharyngeal necrosis was confirmed by nasopharyngeal MRI, electronic nasopharyngoscopy and biopsy. Patients with nasopharyngeal necrosis were treated with electronic nasopharyngoscope irrigation debridement, combined with systemic anti-infection and nutritional support therapy. Kaplan-Meier method was used to calculate the survival, and Cox regression analysis was used to analyze the relationship between clinical factors and patients' survival.Results:Nasopharyngeal necrosis occurred in 20 cases of 1020 nasopharyngeal carcinoma patients after the first radical intensity-modulated radiotherapy, with an incidence rate of 1.96%. Odd smell and headache were common in nasopharyngeal necrosis patients. All patients had locally advanced nasopharyngeal carcinoma at initial treatment, including 2 (10%) cases of T 3 stage and 18 (90%) cases of T 4 stage. Nasopharyngeal necrosis occurred in the primary nasopharyngeal lesions. According to the stages of nasopharyngeal necrosis, there were 6 (30%) cases of stage I, 14 (70%) cases of stage II and no stage III. The occurrence time of nasopharyngeal necrosis was from 2 to 24 months after radiotherapy, and the median time was 5 months. All 16 cases of nasopharyngeal necrosis were cured clinically after debridement and irrigation under nasopharyngoscope, systemic anti-infection and symptomatic support treatment. Among them, 9 cases had no necrotic cavity and complete healing and 7 cases had residual necrotic cavity. Four patients died of massive nasopharyngeal hemorrhage or due to the inability to nasopharyngeal irrigation. The 5-year survival rates were 37.5% and 85.7% in patients with and without internal carotid artery involvement ( P=0.008), and 25.0% and 77.8% in patients with and without diabetes mellitus ( P=0.016). Univariate Cox regression analysis showed that necrotic lesions involving internal carotid artery ( HR=5.80, 95% CI=1.14-29.38, P=0.034) and diabetes mellitus ( HR=10.24, 95% CI=1.19-88.04, P=0.034) were the influencing factors of overall survival. Conclusions:Nasopharyngoscope irrigation debridement combined with anti-inflammation and nutritional support treatment are effective interventions for nasopharyngeal necrosis after the first radical intensity-modulated radiotherapy in patients with nasopharyngeal carcinoma. The necrosis involving the internal carotid artery and diabetes mellitus are important factors affecting the survival of patients. Vascular invasion caused by vascular rupture is the main cause of death.

OBJECTIVE To explore the predictive factors of cefoperazone/sulbactam-induced thrombocytopenia in adult inpatients， and to establish and validate the nomogram prediction model. METHODS Data of adult inpatients treated with cefoperazone/sulbactam in Xi’an Central Hospital from Jun. 30th， 2021 to Jun. 30th， 2023 were retrospectively collected. The training set and internal validation set were randomly constructed in a 7∶3 ratio. Singler factor and multifactor Logistic regression analysis were used to screen the independent predictors of cefoperazone/sulbactam-induced thrombocytopenia. The nomogram was drawn by using “RMS” of R 4.0.3 software， and the predictive performance of the model was evaluated by the receiver operating characteristic curve and C-index curve. Hosmer-Lemeshow goodness-of-fit test was used to evaluate the calibration degree of the model. Using the same standard， the clinical data of hospitalized patients receiving cefoperazone/sulbactam in Xi’an First Hospital in the same period were collected for external validation of the nomogram prediction model. RESULTS A total of 1 045 patients in Xi’an Central Hospital were included in this study， among which 67 patients suffered from cefoperazone/sulbactam-induced thrombocytopenia， with an incidence of 6.41%. After the false positive patients were excluded， 473 patients were included finally， including 331 in the training set and 142 in theinternal validation set. Multifactor Logistic regression analysis showed that age [OR＝1.043， 95%CI （1.017， 1.070）]， estimated glomerular filtration rate （eGFR） [OR＝0.988，95%CI（0.977， 0.998）]， baseline platelet （PLT） [OR＝0.989， 95%CI（0.982， 0.996）]， nutritional risk [OR＝3.863， 95%CI（1.884， 7.921）] and cumulative defined daily doses （DDDs） [OR＝1.082， 95%CI（1.020， 1.147）] were independent predictors for cefoperazone/sulbactam-induced thrombocytopenia （P＜0.05）. The C-index values of the training set and the internal validation set were 0.824 [95%CI （0.759， 0.890）] and 0.828 [95%CI （0.749， 0.933）]， respectively. The results of the Hosmer-Lemeshow test showed that χ 2 values were 0.441 （P＝0.802） and 1.804 （P＝0.406）. In the external validation set， the C-index value was 0.808 [95%CI （0.672， 0.945）]， the χ 2 value of the Hosmer-Lemeshow test was 0.899 （P＝0.638）. CONCLUSIONS The independent predictors of cefoperazone/sulbactam-induced thrombocytopenia include age， baseline PLT， eGFR， nutritional risk and cumulative DDDs. The model has good predictive efficacy and extrapolation ability， which can help clinic identify the potential risk of cefoperazone/sulbactam-induced thrombocytopenia quickly and accurately.

Objective To investigate the transcriptome differences of ovarian cancer cells after cisplatin(DDP)resistance,and to find potential antagonists based on this screening.Methods DDP-resistant cell line A2780-DDP was constructed with A2780 cells as the research object.Through transcriptome sequencing anal-ysis,the key factors of DDP resistance were found and verified by quantitative real-time PCR(qPCR)and Western blot experiments.Through the screening of small molecule inhibitors,CCK-8 cell viability assay was used to find potential antagonists.Results A2780-DDP were successfully constructed,and it was found that there was no difference in cell proliferation after drug resistance,but the ability of cell invasion and migration was enhanced.Through transcriptome sequencing analysis,it was found that ITGB7 and Akt may be the key genes of A2780-DDP,and qPCR and Western blot showed that they were highly expressed in A2780-DDP.CCK-8 results showed that triptolide(TPL)and Olaparib had good inhibitory effects in DDP-resistant cell lines.Conclusion The ITGB7/Akt pathway plays an important role in DDP resistance,and potential DDP re-sistance antagonists such as TPL can provide new ideas for the treatment of ovarian cancer.