Many triterpenoid compounds have been successfully heterologously synthesized in Saccharomyces cerevisiae. To increase the yield of triterpenoids, various metabolic engineering strategies have been developed. One commonly applied strategy is to enhance the supply of precursors, which has been widely used by researchers. Squalene, as a precursor to triterpenoid biosynthesis, plays a crucial role in the synthesis of these compounds. This study primarily investigates the effect of different squalene levels in chassis strains on the synthesis of triterpenoids(oleanolic acid and ursolic acid), and the underlying mechanisms are further explored using real-time quantitative PCR(qPCR) analysis. The results demonstrate that the chassis strain CB-9-5, which produces high levels of squalene, inhibits the synthesis of oleanolic acid and ursolic acid. In contrast, chassis strains with moderate to low squalene production, such as Y8-1 and CNPK, are more conducive to the synthesis of oleanolic acid and ursolic acid. The qPCR analysis reveals that the expression levels of ERG1, βAS, and CrCYP716A154 in the oleanolic acid-producing strain CB-OA are significantly lower than those in the control strains C-OA and Y-OA, suggesting that high squalene production in the chassis strains suppresses the transcription of certain genes, leading to a reduced yield of triterpenoids. Our findings indicate that when constructing S. cerevisiae strains for triterpenoid production, chassis strains with high squalene content may suppress the expression of certain genes, ultimately lowering their production, whereas chassis strains with moderate squalene levels are more favorable for triterpenoid biosynthesis.
Squalene/analysis* ; Saccharomyces cerevisiae/genetics* ; Triterpenes/metabolism* ; Metabolic Engineering ; Oleanolic Acid/biosynthesis* ; Ursolic Acid

Turning to critical illness is a common stage of various diseases and injuries before death. Patients usually have complex health conditions, while the treatment process involves a wide range of content, along with high requirements for doctor′s professionalism and multi-specialty teamwork, as well as a great demand for time-sensitive treatments. However, this is not matched with critical care professionals and the current state of medical care in China. Telemedicine, which shortens the distance of medical professionals and the gap of disease diagnosis and treatments in various regions through electronic information, can effectively solve the current problem. Therefore, there is an urgent need to develop a standardized, high-quality visualization telemedicine round system .Therefore, experts have been organized to search domestic and foreign literature on telemedicine round for critically ill patients and to form this consensus based on clinical experiences so as to further improve the level of critical care treatments in regions.

Objective To explore the effectiveness of an integrated laparoscopic simulation training course (best essential surgical technique training, BEST) in enhancing laparoscopic peritoneal suturing techniques in surgical residents.Methods As an integrated two-stage program, the BEST course applied basic laparoscopic training system with simple molds in phase Ⅰ training, and then adopted advanced laparoscopic training system, 3D Laparoscope and ex-vivo animal models in phase Ⅱ training. The laparoscopic suturing techniques were practiced in phase Ⅱ training. From August 2021 to July 2024, surgical residents in the second year of the national standardized training program were divided into pilot and control groups based on whether they had undergone the BEST course. Two cases of laparoscopic peritoneal suture were performed by the surgical residents under supervision in the department of gastrointestinal surgery. The operative time, quality of suture, and independent completion rate were compared between the two groups.Results A total of 33 surgical residents (19 in pilot group and 14 in control group) were included in this study, and a total of 66 cases of laparoscopic peritoneal suture were performed (38 in pilot group and 28 in control group). The operative time was significantly shorter in pilot group than that in control group (15.7 min vs. 17.5 min, P=0.025). The quality of suture was significantly better in pilot group compared to control group (P=0.023). In pilot group, all peritoneal sutures were performed by residents independently, whereas in control group, 3 cases (10.7%) were assisted by the supervisor, and the independent completion rate was different significantly (P=0.039).Conclusions The BEST course can help improve surgical residents′ laparoscopic peritoneal suturing techniques and could be promoted in the national standardized training program for surgical residents.

Objective To investigate the anatomical and microscopic structures of interstitial fluid flow channels in the skin tissue of hand dorsum in human cadavers.Methods Totally 7 fresh cadavers within 12 hours post-mortem were included.MRI was used to observe the distribution of interstitial fluid flow from the first phalanx of the fingers to the wrist,precisely locating the flow channels.Based on imaging results,histological analyses were conducted to determine the histological characteristics of the flow channels.Furthermore,multi-immunofluorescence and microcomputed tomography(Micro-CT)techniques were employed to analyze the channels,and image post-processing was used to elucidate their anatomical structures at the microscopic level.Results After injecting a contrast agent into the first phalanx of ten finger specimens and applying repeated pressure,MRI image revealed centripetal long-range interstitial fluid flow along channels distinct from blood vessels and lymphatic vessels.Histological analysis and Micro-CT further confirmed that the flow primarily occurred within the fibrous connective tissue and adventitia of the skin.Conclusion The orderly fibrous connective tissue and adventitia in the skin form the interstitial fluid flow channels in the human hand dorsum skin,named as"stromal membrane channels"in the skin.

Turning to critical illness is a common stage of various diseases and injuries before death. Patients usually have complex health conditions, while the treatment process involves a wide range of content, along with high requirements for doctor′s professionalism and multi-specialty teamwork, as well as a great demand for time-sensitive treatments. However, this is not matched with critical care professionals and the current state of medical care in China. Telemedicine, which shortens the distance of medical professionals and the gap of disease diagnosis and treatments in various regions through electronic information, can effectively solve the current problem. Therefore, there is an urgent need to develop a standardized, high-quality visualization telemedicine round system .Therefore, experts have been organized to search domestic and foreign literature on telemedicine round for critically ill patients and to form this consensus based on clinical experiences so as to further improve the level of critical care treatments in regions.

Objective To observe the effect of multi-modal hand hygiene(HH)intervention on HH compliance,as well as the relationship between HH compliance and the healthcare-associated(HA)case infection incidence.Methods From 2014 to 2022,the infection control team in a tertiary first-class hospital implemented multi-modal HH intervention for health care workers(HCWs).The changing trend of HH monitoring data,the correlation be-tween HH compliance rate and HA case infection incidence were analyzed retrospectively.Results The consump-tion of HH products in the wards showed a stable upward trend;HH compliance rate increased from 64.98％in 2014 to 85.01％in 2022(P＜0.001),and HA case infection incidence decreased from 1.21％to 0.83％(P＜0.05).HH compliance rate was negatively correlated with HA case infection incidence(r=-0.369,P=0.027).HH compliance rates in different regions and job posts in each quarter were increased(P＜0.001).For 5 different HH moments in each quarter,HH compliance rate fluctuated slightly before sterile manipulation and after touching patient;presented rising trend after touching surroundings around patient,and decreased before touching patient and after touching patient's body fluid since 2020(P＜0.001).Conclusion Multi-modal HH intervention can im-prove the HH compliance of HCWs,improving their HH awareness is conducive to reducing HA case infection incidence.

Objective To explore the efficacy and safety of recombinant human anti-severe acute respiratory syn-drome coronavirus 2(anti-SARS-CoV-2)monoclonal antibody injection(F61 injection)in the treatment of patients with coronavirus disease 2019(COVID-19)combined with renal damage.Methods Patients with COVID-19 and renal damage who visited the PLA General Hospital from January to February 2023 were selected.Subjects were randomly divided into two groups.Control group was treated with conventional anti-COVID-19 therapy,while trial group was treated with conventional anti-COVID-19 therapy combined with F61 injection.A 15-day follow-up was conducted after drug administration.Clinical symptoms,laboratory tests,electrocardiogram,and chest CT of pa-tients were performed to analyze the efficacy and safety of F61 injection.Results Twelve subjects(7 in trial group and 5 in control group)were included in study.Neither group had any clinical progression or death cases.The ave-rage time for negative conversion of nucleic acid of SARS-CoV-2 in control group and trial group were 3.2 days and 1.57 days(P=0.046),respectively.The scores of COVID-19 related target symptom in the trial group on the 3rd and 5th day after medication were both lower than those of the control group(both P＜0.05).According to the clinical staging and World Health Organization 10-point graded disease progression scale,both groups of subjects improved but didn't show statistical differences(P＞0.05).For safety,trial group didn't present any infusion-re-lated adverse event.Subjects in both groups demonstrated varying degrees of elevated blood glucose,elevated urine glucose,elevated urobilinogen,positive urine casts,and cardiac arrhythmia,but the differences were not statistica-lly significant(all P＞0.05).Conclusion F61 injection has initially demonstrated safety and clinical benefit in trea-ting patients with COVID-19 combined with renal damage.As the domestically produced drug,it has good clinical accessibility and may provide more options for clinical practice.

Objective To investigate the role and mechanism of epithelial-mesenchymal transition(EMT)in a rat model of bronchopulmonary dysplasia(BPD).Methods The experiment consisted of two parts.(1)Forty-eight preterm rats were randomly divided into a normoxia group and a hyperoxia group,with 24 rats in each group.The hyperoxia group was exposed to 85%oxygen to establish a BPD model,while the normoxia group was kept in room air at normal pressure.Lung tissue samples were collected on days 1,4,7,and 14 of the experiment.(2)Rat type II alveolar epithelial cells(RLE-6TN)were randomly divided into a normoxia group(cultured in air)and a hyperoxia group(cultured in 95%oxygen),and cell samples were collected 12,24,and 48 hours after hyperoxia exposure.Hematoxylin-eosin staining was used to observe alveolarization in preterm rat lungs,and immunofluorescence was used to detect the co-localization of surfactant protein C(SPC)and α-smooth muscle actin(α-SMA)in preterm rat lung tissue and RLE-6TN cells.Quantitative real-time polymerase chain reaction and protein immunoblotting were used to detect the expression levels of EMT-related mRNA and proteins in preterm rat lung tissue and RLE-6TN cells.Results(1)Compared with the normoxia group,the hyperoxia group showed blocked alveolarization and simplified alveolar structure after 7 days of hyperoxia exposure.Co-localization of SPC and α-SMA was observed in lung tissue,with decreased SPC expression and increased α-SMA expression in the hyperoxia group at 7 and 14 days of hyperoxia exposure compared to the normoxia group.In the hyperoxia group,the mRNA and protein levels of TGF-β1,α-SMA,and N-cadherin were increased,while the mRNA and protein levels of SPC and E-cadherin were decreased at 7 and 14 days of hyperoxia exposure compared to the normoxia group(P<0.05).(2)SPC and α-SMA was observed in RLE-6TN cells,with decreased SPC expression and increased α-SMA expression in the hyperoxia group at 24 and 48 hours of hyperoxia exposure compared to the normoxia group.Compared to the normoxia group,the mRNA and protein levels of SPC and E-cadherin in the hyperoxia group were decreased,while the mRNA and protein levels of TGF-β1,α-SMA,and E-cadherin in the hyperoxia group increased at 48 hours of hyperoxia exposure(P<0.05).Conclusions EMT disrupts the tight connections between alveolar epithelial cells in a preterm rat model of BPD,leading to simplified alveolar structure and abnormal development,and is involved in the development of BPD.

ObjectiveTo examine the current status of preschoolers' eating behaviors and investigate its correlation with family cohesion and adaptability. MethodsA cross-sectional study was conducted involving 21，954 preschoolers and their families from Pingshan District， Shenzhen， between September 2021 and December 2021. A general demographic questionnaire， the Chinese version of Family Adaptability and Cohesion Evaluation Scale Ⅱ （FACESⅡ-CV） and Chinese Preschoolers’ Eating Behavior Questionnaire （CPEBQ） were used to collect the relevant information. Multiple linear regression was used to analyze the association of family cohesion and adaptability with eating behaviors of preschoolers. ResultsTypes of family cohesion and adaptability were significantly correlated with all the 7 dimensions of preschoolers' eating behaviors， including food fussiness （R²=0.252， F=114.457， P<0.001）， food responsiveness （R² = 0.111， F =24.973， P<0.001）， eating habit （R²= 0.304， F =139.658， P<0.001）， satiety responsiveness （R² = 0.259， F =105.332， P<0.001）， external eating （R² = 0.182， F =50.150， P<0.001）， emotional eating （R² = 0.234， F =91.084， P<0.001） and initiative eating （R² = 0.349， F =168.608， P<0.001）. After adjusting for confounding factors， our study showed that types of family cohesion and adaptability were independent predictors of preschoolers' eating behaviors （P<0.05）. ConclusionsTypes of family cohesion and adaptability have a significant predictive effect on the 7 dimensions of preschoolers' eating behaviors. Higher scores of family cohesion and adaptability imply stronger initiative eating ability and less poor dietary behaviors in preschoolers.

A rich diversity of wild medicinal plant resources is distributed in China, but the breeding of new plant varieties of Chinese medicinal plants started late and the breeding level is relatively weak. Chinese medicinal plant resources are the foundation for new varieties breeding, and the plant variety rights(PVP) are of great significance for the protection and development of germplasm resources. However, most Chinese medicinal plants do not have a distinctness, uniformity, and stability(DUS) testing guideline. The Ministry of Agriculture and Rural Affairs has put 191 plant species(genera) on protection lists, of which only 30 are medicinal species(genera). At the same time, only 29 of 293 species(genera) plants in the Protection List of New Plant Varieties of the People's Republic of China(Forest and Grass) belong to Chinese medicinal plants. The number of PVP applications and authorization of Chinese medicinal plants is rare, and the composition of variety is unreasonable. Up to now, 29 species(genera) of DUS test guidelines for Chinese medicinal plants have been developed. Some basic problems in the breeding of new varieties of Chinese medicinal plants have appeared, such as the small number of new varieties and insufficient utilization of Chinese medicinal plant resources. This paper reviewed the current situation of breeding of new varieties of Chinese medicinal plants and the research progress of DUS test guidelines in China and discussed the application of biotechnology in the field of Chinese medicinal plant breeding and the existing problems in DUS testing. This paper guides the further application of DUS to protect and utilize the germplasm resources of Chinese medicinal plants.
Agriculture ; Biotechnology ; Plant Breeding ; Plants, Medicinal/genetics*