As a biocatalyst, laccase has been widely studied and applied in the papermaking industry. However, the low catalytic efficiency and poor stability of natural laccase limit its application in the pulping process. To develop the laccase with high activity and strong tolerance, we carried out directed evolution for modification of the laccase derived from Bacillus pumilus and screened out the mutants F282L/F306L and Q275P from the random mutant library by high-throughput screening. The specific activities of F282L/F306L and Q275P were 280.87 U/mg and 453.94 U/mg, respectively, which were 1.42 times and 2.30 times that of the wild-type laccase. Q275P demonstrated significantly improved thermal stability, with the relative activity 20% higher than that of the wild-type laccase after incubation at 40 ℃, 50 ℃, and 70 ℃ for 4 h. F282L/F306L and Q275P showed greater tolerance to metal ions and organic solvents than the wild-type laccase. The K_m value of the wild-type laccase was 374.97 μmo/L, and those of F282L/F306L and Q275P were reduced to 318.96 μmo/L and 360.71 μmo/L, respectively, which suggested that the substrate affinity of laccase was improved after mutation. The k_cat values of F282L/F306L and Q275P for the substrate ABTS were 574.00 s^-1 and 898.03 s^-1, respectively, which were 1.1 times and 1.7 times that of the wild-type laccase, indicating the improved catalytic efficiency. Q275P demonstrated better performance than the wild-type laccase in pulping, as manifested by the reduction of 0.82 in the Kappa number and the increases of 2.00% ISO, 7.8%, and 7.2% in whiteness, tensile index, and breaking length, respectively. This work lays a foundation for improving the adaptation of laccase to the environment of the papermaking industry.
Laccase/chemistry* ; Directed Molecular Evolution ; Enzyme Stability ; Bacillus pumilus/genetics* ; Mutation ; Biocatalysis ; Catalysis

Background Job burnout and depressive symptoms are prevalent among occupational populations, with a close relationship between them. Sleep quality, as a potential mediating factor, significantly affects the mental health of workers. Objective To explore the relationship between job burnout, sleep quality, and depressive symptoms, and determine whether sleep quality mediates the relationship between job burnout and depressive symptoms. Methods From April 25 to May 1, 2024, this study employed cluster sampling to conduct a questionnaire survey among individuals engaged in various occupations across five cities in the Ningxia Hui Autonomous Region. The questionnaires included socio-demographic information, as well as the Chinese Maslach Burnout Inventory (CMBI), the Pittsburgh Sleep Quality Index (PSQI), and the Patient Health Questionnaire-9 (PHQ-9) for assessing burnout, sleep quality, and depressive symptoms, respectively. Out of the 4106 questionnaires distributed, a total of 3837 questionnaires were valid, and the valid recovery rate was 93.45%. The distribution among demographic variables in burnout, sleep quality and depressive symptoms were statistically analyzed. A binary logistic regression model was used for multifactor correlation analysis; Pearson correlation was used to test the correlation between burnout, sleep quality, and depressed mood. Modelling and mediated effect path mapping were performed using Amos 24.0 software. Results The postive rate of occupational burnout in the workers was 97.49% (3741/3837), the positive rate of poor sleep quality was 66.77% (2526/3837), and the positive rate of depressive symptoms was 75.68% (2904/3837). There were statistically significant differences in depressive symptoms by ages, shift types, working years, marital status, smoking habits, drinking habits, and exercising frequency (P < 0.05). The logistic model indicated that working years, drinking habits, job burnout, and overall sleep quality were significant factors influencing the occurrence of depressive symptoms (P < 0.05). The correlation analysis revealed positive correlations between depressive symptom scores and job burnout scores (r=0.045, P < 0.01), between depressive symptom scores and sleep quality scores (r=0.480, P < 0.01), and between job burnout scores and sleep quality scores (r=0.054, P < 0.01). Furthermore, the indirect effect of job burnout on depressive symptoms through sleep quality was 0.100 (95%CI: 0.204, 0.252; P < 0.01). Conclusion Job burnout and sleep quality are significant factors associated with the occurrence of depressive symptoms among occupational populations, and sleep quality plays a partial mediating role in depressive symptoms associated with job burnout. This finding may provide a scientific basis for developing intervention strategies to control depressive symptoms among workers.

Hyperthyroidism is a prevalent endocrine disorder commonly managed with antithyroid medications, radioactive iodine, or surgical intervention. Conventionally, thyroidectomy is performed only after achieving a euthyroid state to minimize intraoperative and postoperative complications. However, emerging evidence suggests that, under specific conditions, thyroidectomy may be safely conducted even in the absence of complete preoperative disease controlled. This review provides an expert endocrinologist′s perspective on the safety and feasibility of thyroid surgery in patients with uncontrolled hyperthyroidism, examines various preoperative optimization strategies, and underscores the critical role of perioperative management in ensuring optimal surgical outcomes.

Hyperthyroidism is a prevalent endocrine disorder commonly managed with antithyroid medications, radioactive iodine, or surgical intervention. Conventionally, thyroidectomy is performed only after achieving a euthyroid state to minimize intraoperative and postoperative complications. However, emerging evidence suggests that, under specific conditions, thyroidectomy may be safely conducted even in the absence of complete preoperative disease controlled. This review provides an expert endocrinologist′s perspective on the safety and feasibility of thyroid surgery in patients with uncontrolled hyperthyroidism, examines various preoperative optimization strategies, and underscores the critical role of perioperative management in ensuring optimal surgical outcomes.

Mitochondria are the main site of energy metabolism within cells,generating a substantial amount of ATP to supply energy to the human body.Research has shown that alterations in mitochondrial structure and function exist in individuals with schizophrenia,suggesting their potential impact on the onset of psychiatric disorders and clinical treatment efficacy.Therefore,understanding the research progress on the genetic mechanisms,pathological processes,image manifestations of schizophrenia and mitochondrial quality control,and summarizing the relevant evidence of mitochondrial-related targets as potential therapeutic targets for schizophrenia,can provide references for further research.

After years of development,the advantages of computer-assisted orthognathic surgery have been widely recognized.However,the clinical application of this technology is challenging.Each step may generate errors from data acquisition,computer-assisted diagnosis,and computer-assisted surgical design,causing errors to be transferred from the virtual surgical plan to the operation.The accumulation and amplification of errors will affect the final surgical ef-fect.Currently,digital devices,such as intraoral scanners,are being explored for error control,utilizing automation methods and algorithms,and implementing personalized bone positioning methods.Moreover,there are still many prob-lems that have not been fully resolved,such as precise simulation of postoperative soft tissue,functional assessment of mandibular movement,and absorbable internal fixation materials.Fully understanding computer-assisted orthognathic surgery's limitations could provide direction for optimizing existing methods while helping clinicians avoid risks and maximize its advantages to achieve the best outcome.Many emerging and cutting-edge technologies,such as personal-ized titanium plates,artificial intelligence,and surgical robots,will further promote the development of this discipline.We can expect future optimization of digital orthognathic surgical technology by innovations in automation,intelligence,and personalization.

Schizophrenia is a common chronic mental disorder.Cognitive dysfunction is one of its core symptoms,which severely affects the social functioning of patients.Currently,antipsychotic medication treatments have poor efficacy in improving cognitive functions.Recent studies have found that metformin can improve cognitive dysfunction in patients with schizophrenia.However,the mechanism of action remains unclear.This review summarizes the therapeutic effects of metformin on cognitive dysfunction in schizophrenia patients such as improving insulin resistance,repairing neuronal damage,regulating neuroimmunity,and combating oxidative stress,thereby providing new insights for the treatment of cognitive dysfunction in schizophrenia.

Late-onset cobalamin C (cblC) deficiency is an inherited organic acid metabolic disorder characterized by clinical heterogeneity, which often presents challenges in accurate diagnosis. This article presents a case study of a young female patient who initially experienced epileptic-like seizures. Over a span of 9 years, she subsequently developed psychotic symptoms. Her condition has been steadily deteriorating over a period of 16 years, leading to mutism, loss of ambulation, dysphagia, and urinary and fecal incontinence. Although electroencephalography and cranial computed tomography did not show significant findings during the course of the illness, cranial magnetic resonance imaging showed evidence of cerebral atrophy. Biochemical analysis revealed elevated levels of blood homocysteine and urinary methylmalonic acid-2. Genetic testing identified two pathogenic mutations in the MMACHC gene, confirming the diagnosis of late-onset cobalamin C (cblC) deficiency. Despite receiving interventions such as antiepileptic and antipsychotic medications during the diagnostic and therapeutic phases, the patient′s clinical progress remained limited.Following the definitive diagnosis, targeted metabolic therapy was initiated, leading to significant clinical improvement. This article provides a comprehensive review of the patient′s clinical data, along with a synthesis of relevant literature, in order to enhance the awareness of psychiatric practitioners regarding this rare disorder. The primary objective is to promote early identification, prompt diagnosis, and timely intervention.

Late-onset cobalamin C (cblC) deficiency is an inherited organic acid metabolic disorder characterized by clinical heterogeneity, which often presents challenges in accurate diagnosis. This article presents a case study of a young female patient who initially experienced epileptic-like seizures. Over a span of 9 years, she subsequently developed psychotic symptoms. Her condition has been steadily deteriorating over a period of 16 years, leading to mutism, loss of ambulation, dysphagia, and urinary and fecal incontinence. Although electroencephalography and cranial computed tomography did not show significant findings during the course of the illness, cranial magnetic resonance imaging showed evidence of cerebral atrophy. Biochemical analysis revealed elevated levels of blood homocysteine and urinary methylmalonic acid-2. Genetic testing identified two pathogenic mutations in the MMACHC gene, confirming the diagnosis of late-onset cobalamin C (cblC) deficiency. Despite receiving interventions such as antiepileptic and antipsychotic medications during the diagnostic and therapeutic phases, the patient′s clinical progress remained limited.Following the definitive diagnosis, targeted metabolic therapy was initiated, leading to significant clinical improvement. This article provides a comprehensive review of the patient′s clinical data, along with a synthesis of relevant literature, in order to enhance the awareness of psychiatric practitioners regarding this rare disorder. The primary objective is to promote early identification, prompt diagnosis, and timely intervention.

Objective:To investigate the association between plasma uric acid and hypertension and the gender difference in community-dwelling middle-aged and elderly population.Methods:A community-based cross-sectional study was conducted in Beijing Tongzhou Yongshun Community Health Service Center from June to December 2021, among residents aged 45 years or older selected by cluster sampling method. According to plasma uric acid (UA) level in quartiles, the subjects were divided into 4 groups; and stratified by gender, the subjects were further divided into subgroups. Multivariate logistic regression model was used to analyze the related factors of hypertension, and restricted cubic spline fitting logistic regression model was used to analyze the nonlinear association between uric acid and hypertension and the cut-off values of uric acid.Results:A total of 6 229 residents with the age of (63.2±7.3) years were enrolled in the study. In 1 874 male participants (30.1%), 946 participants (50.5%) had hypertension, and the uric acid level was 359 (309, 418)μmol/L; in 4 355 female participants (69.9%), 2 003 participants (46.0%) had hypertension, and the uric acid level was 306 (261, 359)μmol/L. Multivariate logistic regression analysis showed that after adjusting for factors that were statistically significant in univariate analyses or potentially clinically relevant (including age, body mass index, diabetes mellitus, coronary heart disease, cerebrovascular disease, albumin, estimated glomerular filtration rate, and cholesterol), uric acid was independently associated with hypertension ( P<0.001), for total participants the risk of hypertension in Q4 group was 1.33 times of that in Q1 group ( OR=1.33,95% CI 1.13-1.56, P=0.001); while for females the risk of hypertension in Q4 group was 1.38 times of that in Q1 group ( OR=1.38,95% CI 1.13-1.68, P=0.002), but no significant association was observed for males ( P>0.05). The results of restricted cubic spline fitting logistic regression analysis showed that there was a linear association between uric acid level and hypertension in the total population and males, and the risk of hypertension increased with uric acid level ( P<0.001 for the total population, P=0.016 for male). However, there was a non-linear association in females. When uric acid>307 μmol/L in females, the risk of hypertension increased significantly as the level of uric acid increased ( P<0.001). Conclusions:Uric acid level was independently associated with hypertension in the community-dwelling middle-aged and elderly population, and there was a gender difference in the correlation. The association was nonlinear in females and the cut-off value of uric acid in females was 307 μmol/L.