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

Objective To explore the network structure of anxiety,depression and sleep among individuals under long-term high-altitude exposure.Methods A total of 303 subjects who had resided at high altitudes for more than 6 months on end were selected.The insomnia severity index(ISI),patient health questionnaire(PHQ-9),and generalized anxiety disorder scale(GAD-7)were employed to assess insomnia,depression and anxiety before network analysis was conducted to identify the central and bridge nodes in the symptom network.Results The incidence of moderate or severe depression,anxiety and insomnia were 38.9％[95％confidence interval(CI):33.4％-44.5％],23.1％(95％CI:18.3％-27.9％),and 18.5％(95％CI:14.1％-22.9％),respectively."Noticeability of sleep problems by others"had the highest expected influence centrality,followed by"sleep maintenance""uncontrollable worry""restlessness"and"sleep problems".Five bridge symptoms were identified:"sad mood""sleep problems""restlessness""feeling afraid"and"trouble relaxing".Conclusion Sleep-related symptoms play a crucial role in the overall network structure,serving as both central and bridge nodes.Additionally,the"feeling down or depressed"acts as a bridge node and holds importance in the comorbidity network of anxiety and depression.Targeting these key symptoms through intervention and prevention strategies may improve the psychological well-being of individuals with long-term residence in high-altitude regions.

Objective To carry out rigid-body inverse dynamics modelling and analysis of a self-designed 6RSS parallel bio-inspired masticatory robot.Methods Firstly,the functions of kinematic variables including translational/rotational velocities and accelerations were derived for rigid-body inverse dynamics modelling.Secondly,the rigid-body inverse dynamics model was established with the Newton-Euler's law.Finally,the chewing motion trajectories of the oral health volunteers were tracked and numerical calculations were carried out in the case where the robot was subjected to a chewing reaction force.Results Numerical calculations showed that the driving torque and the constraint force of the robot peaked when the chewing reaction force was at its maximum.Conclusion The external force has a large impact on the inverse dynamics of the robot,and theoretical references are provided for the motion control and optimal design of the robot.[Chinese Medical Equipment Journal,2024,45(3):16-22]

Background::Although overnight fasting is recommended prior to endoscopic retrograde cholangiopancreatography (ERCP), the benefits and safety of high-carbohydrate fluid diet (CFD) intake 2 h before ERCP remain unclear. This study aimed to analyze whether high-CFD intake 2 h before ERCP can be safe and accelerate patients’ recovery.Methods::This prospective, multicenter, randomized controlled trial involved 15 tertiary ERCP centers. A total of 1330 patients were randomized into CFD group ( n = 665) and fasting group ( n = 665). The CFD group received 400 mL of maltodextrin orally 2 h before ERCP, while the control group abstained from food/water overnight (>6 h) before ERCP. All ERCP procedures were performed using deep sedation with intravenous propofol. The investigators were blinded but not the patients. The primary outcomes included postoperative fatigue and abdominal pain score, and the secondary outcomes included complications and changes in metabolic indicators. The outcomes were analyzed according to a modified intention-to-treat principle. Results::The post-ERCP fatigue scores were significantly lower at 4 h (4.1 ± 2.6 vs. 4.8 ± 2.8, t = 4.23, P <0.001) and 20 h (2.4 ± 2.1 vs. 3.4 ± 2.4, t= 7.94, P <0.001) in the CFD group, with least-squares mean differences of 0.48 (95% confidence interval [CI]: 0.26–0.71, P <0.001) and 0.76 (95% CI: 0.57–0.95, P <0.001), respectively. The 4-h pain scores (2.1 ± 1.7 vs. 2.2 ± 1.7, t = 2.60, P = 0.009, with a least-squares mean difference of 0.21 [95% CI: 0.05–0.37]) and positive urine ketone levels (7.7% [39/509] vs. 15.4% [82/533], χ2 = 15.13, P <0.001) were lower in the CFD group. The CFD group had significantly less cholangitis (2.1% [13/634] vs. 4.0% [26/658], χ2 = 3.99, P = 0.046) but not pancreatitis (5.5% [35/634] vs. 6.5% [43/658], χ2 = 0.59, P = 0.444). Subgroup analysis revealed that CFD reduced the incidence of complications in patients with native papilla (odds ratio [OR]: 0.61, 95% CI: 0.39–0.95, P = 0.028) in the multivariable models. Conclusion::Ingesting 400 mL of CFD 2 h before ERCP is safe, with a reduction in post-ERCP fatigue, abdominal pain, and cholangitis during recovery.Trail Registration::ClinicalTrials.gov, No. NCT03075280.

Objective To investigate the effect of smoking on the semen quality in infertile men.Methods A total of 360 male infertility patients were enrolled and divided into the smoking group(n=190)and non-smoking group(n=170)based on whether they smoked or not.Furthermore,the smoking group was subdivided into group A(≤10 sticks/d,n=63),group B(11～20 sticks/d,n=80),and group C(>20 sticks/d group,n=47)according to the amount of smoking.Semen volume,liquefaction time,sperm concentration,motility,DNA fragmentation rate and normal morphological rate were observed and compared between and within the groups.Results There were significant differences in semen volume,liquefaction time,sperm motility,normal morphological rate and DNA fragmentation rate between the smoking group and the non-smoking group(P<0.05).The semen volume,sperm motility and normal morphological rate of the smoking group were lower than those in the non-smoking group,and the DNA fragmentation rate and semen liquefaction time were higher than those in the non-smoking group.And with the increase of smoking volume,sperm motility and normal morphological rate decreased,semen liquefaction time and DNA fragmentation rate increased,and there was no significant difference in the sperm concentration between the smoking group and non-smoking group(P>0.05).There was no significant difference in the semen volume between the three groups with different smoking amounts(P>0.05).Conclusion Smoking has a negative impact on the sperm quality parameters such as semen volume,sperm motility,normal morphological rate,sperm motility,liquefaction time and DNA fragmentation,and the effect of heavy smoking is particularly obvious.We should strengthen the comprehensive health education,promote the healthy lifestyles and reduce smoking.

Objective:To investigate the consistency of domestic F-STROKE, NeuBrainCARE MRI automatic post-processing software and RAPID MRI automatic post-processing software in the output of infarction core area volume, time-to-maximum volume and ischemic penumbra volume in patients with acute ischemic stroke.Methods:The research was cross-sectional. The clinical and imaging data of patients with acute ischemic stroke from January 2016 to March 2021 were retrospectively collected, including 149 cases from Shanghai Fourth People′s Hospital Affiliated to Tongji University (Center 1), 120 cases from Langfang Changzheng Hospital of Hebei Province (Center 2), and 45 cases from Wuzhou Workers Hospital (Center 3). All patients underwent diffusion weighted imaging (DWI) and dynamic magnetic sensitivity contrast-perfusion weighted imaging (DSC-PWI). RAPID, F-STROKE and NeuBrainCARE automatic post-processing software were used to perform automatic post-processing analysis of MRI images of all patients with acute ischemic stroke. The infarct core (apparent diffusion coefficient<620×10 -6 mm 2/s) volume, time-to-maximum (T max>6 s) volume and the ischemic penumbra (PWI-DWI mismatch) volume were output. The Wilcoxon test was used to analyze the difference between F-STROKE, NeuBrainCARE, and RAPID software outputs of infarct core volume, time to maximum peak volume, and ischemic penumbra volume. Bland-Altman and intraclass correlation coefficient ( ICC) were used to analyze the consistency of the infarct core volume, time-to-maximum volume and ischemic penumbra volume output by F-STROKE, NeuBrainCARE and RAPID software. Results:There were statistically significant differences in the core infarct volume between F-STROKE and RAPID software, NeuBrainCARE and RAPID software ( Z=-10.17, -5.43, both P<0.001). There were significant differences in the time-to-maximum volume between F-STROKE and RAPID software, NeuBrainCARE and RAPID software ( Z=-3.17, -5.51, both P<0.05). There was no significant difference in the ischemic penumbra volume between F-STROKE software and RAPID software ( Z=-1.43, P=0.153), and there was significant difference in the ischemic penumbra volume between NeuBrainCARE software and RAPID software ( Z=-6.45, P<0.05). Bland-Altman analysis showed that the values within the limits of agreement accounted for more than 93.31% of all point values. ICC analysis showed high agreement between F-STROKE, NeuBrainCARE, and RAPID software outputs of infarct core volume, time to maximum peak volume, and ischemic penumbra volume ( ICC>0.6). Conclusion:Domestic F-STROKE software, NeuBrainCARE software and RAPID software have good consistency in evaluating the infarct core volume, time-to-maximum volume and ischemic penumbra volume in patients with acute ischemic stroke, which is worthy of clinical promotion.

Objective To explore the clinical characteristics and treatment scheme of patients with spinal infection caused by Prevotella intermedia(P.intermedia).Methods Clinical diagnosis and treatment processes of a patient with spinal infection caused by P.intermedia admitted to the spinal surgery department of a hospital were summa-rized,and relevant literature was retrieved from database for reviewing.Results The patient,a 50 year old male,was admitted to the hospital due to"lumbago pain complicated with pain in double lower extremities for 2 months".The lesion tissue was taken for metagenomic next-generation sequencing(mNGS)detection,which detected P.in-termedia,and the patient was diagnosed with P.intermedia spondylitis.After treatments with open lesion clea-rance,tube rinsing+autologous bone transplantation fusion internal fixation,intravenous drip of ceftriaxone sodium and metronidazole,as well as metronidazole rinsing,infection was under control.A total of 16 available papers were retrieved,together with this case,a total of 17 patients were included,with 7 males and 10 females.The main risk factors were diabetes and history of corticosteroid use(35.3％).The most common invasion sites were lumbar ver-tebra(n=12)and thoracic vertebra(n=6).13 cases were positive for pathogen culture,3 cases were positive for molecular detection,and 1 case was positive for staining microscopy.17 patients received anti-anaerobic bacteria treatment,with 14 cases receiving combined surgical treatment.One case died,with a mortality of 5.9％;5 cases had partial neurological impairment,with a disability rate of 29.4％.The survival rate of patients who received treatment of anti-anaerobic bacteria combined with surgery was 92.8％,3 patients only with anti-anaerobic bacteria treatment but without surgery were all cured.Conclusion P.intermedia is an opportunistic pathogeanic bacteria which often causes infection in immunocomprised individuals and is prone to be misdiagnosed.It is recommended to perform mNGS detection to identify the pathogen as early as possible and seize the opportunity for treatment to reduce mortality.

Objective:To assess the trends in case-fatality rates for acute myocardial infarction (AMI) in China from 2015 to 2019.Methods:This study employed a population-based surveillance. Data from the China Registry of Acute Cardiovascular Event (China RACE) were utilized, including AMI cases reported by Grade Ⅱ and Grade Ⅲ hospitals at the disease surveillance sites across China from January 1 st 2015 to December 31 st 2019. The 28-day mortality outcome for reported AMI events was obtained by linking to the national death certificate registry system. The study analyzed the overall and age-standardized case-fatality rates, as well as their annual percent change (APC), during the study period, stratified by gender, age, and region. Results:The overall 28-day case fatality rate for AMI was 28.97% (22 532/77 764) from 2015 to 2019. The age-standardized case-fatality rate for AMI declined significantly from 37.53% in 2015 to 18.58% in 2019, with an APC of -14.33% ( P=0.018). We observed a significant downward trend in case-fatality rates of AMI in both genders (both P<0.05). Among males, the case-fatality rate decreased more steeply in younger males compared to elder counterparts. The most marked decreases were seen in males aged<35 years and 35 to 44 years, with APC of -27.63% ( P=0.007) and -22.65% ( P=0.004), respectively. In females, we observed a relatively stable decrease in case-fatality across age groups. The age-standardized case-fatality rate of AMI in eastern and central China decreased significantly from 2015 to 2019, with the APC of -19.22% ( P=0.006) and -15.62% ( P=0.032) respectively. However, the age-standardized case-fatality rate of AMI in western China remained stable ( P=0.227). Conclusions:The prognosis of AMI has considerably improved from 2015 to 2019 in China, regardless of ages and gender. Inequality in case-fatality rates among geographic regions highlights the need for targeted strategies in AMI prevention in western regions.

Noncarious lesions,a multifactorial condition encompassing tooth attrition,abrasion,and erosion,have a surge in prevalence and required increased attention in clinical practice.These nonbacterial-associated tooth de-fects can compromise aesthetics,phonetics,and mastica-tory functions.When providing full-arch fixed occlusal rehabilitation for such cases,the treatment strategy should extend beyond by restoring dentition morphology and aesthetics.This report details a complex case of erosive dental wear addressed through a fully digital,full-arch fixed occlusal rehabilitation.A 4D virtual patient was created using multiple digital data sources,including intraoral scanning,3D facial scanning,digital facebow registration,and mandibular movement tracing.With a comprehensive understanding of the masticatory system,various types of microinvasive prostheses were customized for each tooth,including labial ve-neers,buccal-occlusal veneers,occlusal veneers,overlays,inlays,and full crowns,were customized for each tooth.The reported digital workflow offered a predictable diagnostic and treatment strategy,which was facilitated by virtual visual-ization and comprehensive quality control throughout the process.

Osteoporotic proximal humeral fracture (OPHF) is one of the common osteoporotic fractures in the aged, with an incidence only lower than vertebral compression fracture, hip fracture, and distal radius fracture. OPHF, secondary to osteoporosis and characterized by poor bone quality, comminuted fracture pattern, slow healing, and severely impaired shoulder joint function, poses a big challenge to the current clinical diagnosis and treatment. In the field of diagnosis, treatment, and rehabilitation of OPHF, traditional Chinese and Western medicine have accumulated rich experience and evidence from evidence-based medicine and achieved favorable outcomes. However, there is still a lack of guidance from a relevant consensus as to how to integrate the advantages of the two medical systems and achieve the integrated diagnosis and treatment. To promote the diagnosis and treatment of OPHF with integrated traditional Chinese and Western medicine, relevant experts from Orthopedic Expert Committee of Geriatric Branch of Chinese Association of Gerontology and Geriatrics, Youth Osteoporosis Group of Orthopedic Branch of Chinese Medical Association, Osteoporosis Group of Orthopedic Surgeon Branch of Chinese Medical Doctor Association, and Osteoporosis Committee of Shanghai Association of Integrated Traditional Chinese and Western Medicine have been organized to formulate Expert consensus on the diagnosis and treatment of osteoporotic proximal humeral fracture with integrated traditional Chinese and Western medicine ( version 2024) by searching related literatures and based on the evidences from evidence-based medicine. This consensus consists of 13 recommendations about the diagnosis, treatment and rehabilitation of OPHF with integrated traditional Chinese medicine and Western medicine, aimed at standardizing, systematizing, and personalizing the diagnosis and treatment of OPHF with integrated traditional Chinse and Western medicine to improve the patients ′ function.