Preparation of (S)-epichlorohydrin using a novel halohydrin dehalogenase by selective conformation adjustment

Chiral epichlorohydrin (ECH) is an attractive intermediate for chiral pharmaceuticals and chemicals preparation. The asymmetric synthesis of chiral ECH using 1,3-dicholoro-2-propanol (1,3-DCP) catalyzed by a haloalcohol dehalogenase (HHDH) was considered as a feasible approach. However, the reverse ring opening reaction caused low optical purity of chiral ECH, thus severely restricts the industrial application of HHDHs. In the present study, a novel selective conformation adjustment strategy was developed with an engineered HheCPS to regulate the kinetic parameters of the forward and reverse reactions, based on site saturation mutation and molecular simulation analysis. The HheCPS mutant E85P was constructed with a markable change in the conformation of (S)-ECH in the substrate pocket and a slight impact on the interaction between 1,3-DCP and the enzyme, which resulted in the kinetic deceleration of the reverse reactions. Compared with HheCPS, the catalytic efficiency (kcat(S)-ECH/Km(S)-ECH) of the reversed reaction dropped to 0.23-fold (from 0.13 to 0.03 mM-1 s-1), while the catalytic efficiency (kcat(1,3-DCP)/Km(1,3-DCP)) of the forward reaction only reduced from 0.83 to 0.71 mM-1 s-1. With 40 mM 1,3-DCP as substrate, HheCPS E85P catalyzed the synthesis of (S)-ECH with the yield up to 55.35% and the e.e. increased from 92.54 to >99%. Our work provided an effective approach for understanding the stereoselective catalytic mechanism as well as the green manufacturing of chiral epoxides.

Development of a real-time impedance matching system for ion cyclotron resonance heating in experimental advanced superconducting tokamak

To achieve stable operation of an ion cyclotron resonance heating (ICRH) system in the Experimental Advanced Superconducting Tokamak (EAST), a real-time impedance matching system needs to be established to respond to antenna load variation during long pulse discharges. A new impedance matching method based on capacitors was proposed in this study. By considering the reflected voltage of the transmission line as the feedback parameter, the real-time impedance-matching system can quickly control the motors based on a programmable logic controller to determine the minimum reflection voltage. A real-time impedance matching system was successfully used on the test platform in the laboratory and on the ICRH system in EAST. A significant result is that we can match the variable impedance within 1 s by suitably adjusting the motor controller to ensure high-power and long-pulse operation of the ICRH system to satisfy the requirements of the EAST experiment.

Design and analysis of radio frequency window for the China Fusion Engineering Test Reactor ion cyclotron range of frequency heating system

The Ion Cyclotron Range of Frequency (ICRF) heating system of the China Fusion Engineering Test Reactor (CFETR) is intended to provide plasma heating with a minimum power output of 20 MW, which demands the Radio Frequency (RF) window to possess a higher performance requirement. This paper presents the design of an RF window for the CFETR ICRF heating system and focuses primarily on the design and confirmation of its electromagnetic performance. The RF window can be effectively matched in the operating frequency range and has an S11 of under -59 dB. The geometry of the cone type ceramics was optimized to reduce the surface tangential electric field distribution. An analysis of the electric field distribution of the RF window at 50 kV indicates that the pressure side was below 2.3 kV/mm and the vacuum side was below 1.3 kV/mm. Furthermore, a transmission line test bench with an open-terminated setup was constructed to conduct withstand voltage tests on the mockup, and the results showed that the mockup could withstand 62 kV for 2 s and 47 kV for 120 s.

Designing a novel (R)-ω-transaminase for asymmetric synthesis of sitagliptin intermediate via motif swapping and semi-rational design

The application of (R)-ω-transaminases as biocatalysts for chiral amine synthesis has been hampered by inadequate stereoselectivity and narrow substrate spectrum. Herein, an effective evolution strategy for (R)-ω-transaminase designing for the asymmetric synthesis of sitagliptin intermediate is presented. Since natural transaminases lack activity toward bulky prositagliptin ketone, transaminase scaffolds with catalytic machinery and activity toward the truncated prositagliptin ketone were firstly screened based on substrate walking principle. A transaminase chimera was established synchronously conferring catalytic activity and (R)-selectivity toward prositagliptin ketone through motif swapping, followed by stepwise evolution. The process resulted in a "best" engineered variant MwTAM8, which exhibited 79.2-fold higher activity than the chimeric scaffold MwTAMc. Structural analysis revealed that the heightened activity is mainly due to the enlarged and adaptive substrate pocket and tunnel. The novel (R)-transaminase exhibited unsatisfied industrial operation stability, which is expected to further modify the protein to enhance its tolerance to temperature, pH, and organic solvents to meet sustainable industrial demands. This study underscores a useful evolution strategy of engineering biocatalysts to confer new properties and functions on enzymes for synthesizing high-value drug intermediates.

[The role of intravoxel incoherent motion diffusion-weighted imaging in distinguishing diabetic nephropathy from non-diabetic renal disease in diabetic patients]

Objective: To investigate the intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) in the differential diagnosis of diabetic nephropathy (DN) and non-diabetic renal disease (NDRD) among patients with type 2 diabetes mellitus (T2DM). Methods: A diagnostic test. In this prospective study, patients with T2DM who underwent both IVIM-DWI and renal biopsy at the First Medical Center of Chinese PLA General Hospital between October 2017 and September 2021 were consecutively enrolled. IVIM-DWI parameters including perfusion fraction (f), pure diffusion coefficient (D), and pseudo-diffusion coefficient (D*) were measured in the renal cortex, medulla, and parenchyma. Patients were divided into the DN group and NDRD group based on the renal biopsy results. IVIM-DWI parameters, clinical information, and diabetes-related biochemical indicators between the two groups were compared using Student's t-test or Mann-Whitney U test. The correlation of IVIM-DWI parameters with diabetic nephropathy histological scores were analyzed using Spearman's correlation analyzes. The diagnostic efficiency of IVIM-DWI parameters for distinguishing between DN and NDRD were assessed using the receiver operating characteristic (ROC) curves. Results: A total of 27 DN patients and 23 NDRD patients were included in this study. The DN group comprised 19 male and 8 female patients, with an average age of 52±9 years. The NDRD group comprised 16 male and 7 female patients, with an average age of 49±10 years. The DN group had a higher D* value in the renal cortex and a lower f value in the renal medulla than the NDRD group (9.84×10-3 mm2/s vs. 7.35×10-3 mm2/s, Z=-3.65; 41.01% vs. 46.74%, Z=-2.29; all P<0.05). The renal medulla D* value was negatively correlated with DN grades, interstitial lesion score, and interstitial fibrosis and tubular atrophy (IFTA) score (r=-0.571, -0.409, -0.409; all P<0.05) while the renal cortex f value was positively correlated with vascular sclerosis score (r=0.413, P=0.032). The renal cortex D* value had the highest area under the curve (AUC) for discriminating between the DN and NDRD groups (AUC=0.802, sensitivity 91.3%, specificity 55.6%). Conclusion: IVIM-derived renal cortex D* value can be used non-invasively to differentiate DN from NDRD in patients with T2DM that can potentially facilitate individualized treatment planning for diabetic patients.

Efficient biosynthesis of Vibegron intermediate using a novel carbonyl reductase based on molecular modification of hydrogen bonding network regulation

Vibegron is a novel, potent, highly selective β3-adrenergic receptor agonist for the treatment of overactive bladder with higher therapeutic capacity and lower side effects. Methyl(2S,3R)-2-((tert-butoxycarbonyl)amino)-3-hydroxy-3-phenylpropanoate ((2S,3R)-aminohydroxy ester) is a key chiral intermediate for the synthesis of Vibegron. A novel carbonyl reductase from Exiguobacterium sp. s126 (EaSDR6) was isolated using data mining technology from GenBank database with preferable catalytic activity. Hydrogen bond network regulation was performed using site-directed saturation mutagenesis and combination mutagenesis. The mutant EaSDR6A138L/S193A was obtained with the activity improvement by 4.58 folds compared with the wild type EaSDR6. The Km of EaSDR6A138L/S193A was decreased from 1.57 mM to 0.67 mM, kcat was increased by 2.17 folds, and the overall catalytic efficiency kcat/Km was increased by 5.07 folds. The organic-aqueous biphasic bioreaction system for the asymmetric synthesis of (2S,3R)-aminohydroxy ester was constructed for the first time. Under the substrate concentration of 150 g/L, the yield of (2S,3R)-aminohydroxy ester was > 99.99%, the e.e. was > 99.99%, and the spatiotemporal yield was 1.55 g/(L·h·g DCW) after 12 h reaction. While the substrate concentration was increased to 200 g/L and the reaction lasted for 36 h, the yield of (2S,3R)-aminohydroxy ester was > 99.99%, the e.e. was > 99.99% and the spatiotemporal yield was 1.05 g/(L·h·g DCW). The substrate concentration and spatiotemporal yield were higher than ever reported.

[Analysis of factors associated with severe bleeding after percutaneous nephrolithotomy and evaluation of interventional embolization efficacy in male patients]

Objective: To explore the factors associated with severe bleeding after percutaneous nephrolithotomy (PCNL) in male patients and evaluate the efficacy of interventional embolization. Methods: A retrospective case series study was conducted at Nankai Hospital of Tianjin, China, from January 2018 to October 2021. The clinical data of 230 male patients with upper urinary tract stones were analyzed. The observation indicators included age, hypertension, diabetes, renal function abnormalities, history of preoperative anticoagulant use, stone size, stone type, number of puncture channels, operation time and degree of hydronephrosis. To describe the clinical characteristics of bleeding after percutaneous nephrolithotomy in men, and analyze the factors associated with severe bleeding after PCNL. Single factor analysis was performed using the Chi-square (χ2) test, and multivariate analysis was performed using logistic regression analysis. Results: Univariate analysis showed that diabetes mellitus (χ2=4.90, P=0.027), abnormal renal function (χ2=18.32, P<0.001), history of preoperative oral anticoagulants (χ2=5.10, P=0.024), abnormal bleeding and coagulation function (χ2=8.22, P=0.004) and the number of puncture channels (χ2=22.08, P<0.001) were the related factors affecting bleeding after PCNL. Multivariate logistic regression analysis showed that diabetes mellitus (P=0.032), abnormal renal function (P<0.001), and the number of puncture channels (P<0.001) were the independent risk factors of bleeding after PCNL. Of the 28 patients with bleeding after PCNL, 25 were treated with interventional embolization, with a technical success rate of 100.0% and a clinical success rate of 89.3%. Conclusions: For patients with renal calculi and comorbid diabetes, renal function abnormalities, and multiple punctures, relevant preventive measures should be actively administered before PCNL to reduce the risk of postoperative bleeding. For patients with severe bleeding of the kidney after PCNL, TAE is a safe and effective minimally invasive treatment method.

[Impact of different diagnostic criteria for assessing mild micro-hepatic encephalopathy in liver cirrhosis: an analysis based on a prospective, multicenter, real-world study]

Objective: To compare the differences in the prevalence of mild micro-hepatic encephalopathy (MHE) among patients with cirrhosis by using the psychometric hepatic encephalopathy score (PHES) and the Stroop smartphone application (Encephal App) test. Methods: This prospective, multi-center, real-world study was initiated by the National Clinical Medical Research Center for Infectious Diseases and the Portal Hypertension Alliance and registered with International ClinicalTrials.gov (NCT05140837). 354 cases of cirrhosis were enrolled in 19 hospitals across the country. PHES (including digital connection tests A and B, digital symbol tests, trajectory drawing tests, and serial management tests) and the Stroop test were conducted in all of them. PHES was differentiated using standard diagnostic criteria established by the two studies in China and South Korea. The Stroop test was evaluated based on the criteria of the research and development team. The impact of different diagnostic standards or methods on the incidence of MHE in patients with cirrhosis was analyzed. Data between groups were differentiated using the t-test, Mann-Whitney U test, and χ (2) test. A kappa test was used to compare the consistency between groups. Results: After PHES, the prevalence of MHE among 354 cases of cirrhosis was 78.53% and 15.25%, respectively, based on Chinese research standards and Korean research normal value standards. However, the prevalence of MHE was 56.78% based on the Stroop test, and the differences in pairwise comparisons among the three groups were statistically significant (kappa = -0.064, P < 0.001). Stratified analysis revealed that the MHE prevalence in three groups of patients with Child-Pugh classes A, B, and C was 74.14%, 83.33%, and 88.24%, respectively, according to the normal value standards of Chinese researchers, while the MHE prevalence rates in three groups of patients with Child-Pugh classes A, B, and C were 8.29%, 23.53%, and 38.24%, respectively, according to the normal value standards of Korean researchers. Furthermore, the prevalence rates of MHE in the three groups of patients with Child-Pugh grades A, B, and C were 52.68%, 58.82%, and 73.53%, respectively, according to the Stroop test standard. However, among the results of each diagnostic standard, the prevalence of MHE showed an increasing trend with an increasing Child-Pugh grade. Further comparison demonstrated that the scores obtained by the number connection test A and the number symbol test were consistent according to the normal value standards of the two studies in China and South Korea (Z = -0.982, -1.702; P = 0.326, 0.089), while the other three sub-tests had significant differences (P < 0.001). Conclusion: The prevalence rate of MHE in the cirrhotic population is high, but the prevalence of MHE obtained by using different diagnostic criteria or methods varies greatly. Therefore, in line with the current changes in demographics and disease spectrum, it is necessary to enroll a larger sample size of a healthy population as a control. Moreover, the establishment of more reliable diagnostic scoring criteria will serve as a basis for obtaining accurate MHE incidence and formulating diagnosis and treatment strategies in cirrhotic populations.

[Recognition of abnormal changes in echocardiographic videos by an artificial intelligence assisted diagnosis model based on 3D CNN]

Objective: To investigate the diagnostic efficiency and clinical application value of an artificial intelligence-assisted diagnosis model based on a three-dimensional convolutional neural network (3D CNN) on echocardiographic videos of patients with hypertensive heart disease, chronic renal failure (CRF) and hypothyroidism with cardiac involvement. Methods: This study is a retrospective study. The patients with hypertensive heart disease, CRF and hypothyroidism with cardiac involvement, who admitted in Henan Provincial People's Hospital from April 2019 to October 2021, were enrolled. Patients were divided into hypertension group, CRF group, and hypothyroidism group. Additionally, a simple random sampling method was used to select control healthy individuals, who underwent physical examination at the same period. The echocardiographic video data of enrolled participants were analyzed. The video data in each group was divided into a training set and an independent testing set in a ratio of 5 to 1. The temporal and spatial characteristics of videos were extracted using an inflated 3D convolutional network (I3D). The artificial intelligence assisted diagnosis model was trained and tested. There was no case overlapped between the training and validation sets. A model was established according to cases or videos based on video data from 3 different views (single apical four chamber (A4C) view, single parasternal left ventricular long-axis (PLAX) view and all views). The statistical analysis of diagnostic performance was completed to calculate sensitivity, specificity and area under the ROC curve (AUC). The time required for the artificial intelligence and ultrasound physicians to process cases was compared. Results: A total of 730 subjects aged (41.9±12.7) years were enrolled, including 362 males (49.6%), and 17 703 videos were collected. There were 212 cases in the hypertensive group, 210 cases in the CRF group, 105 cases in the hypothyroidism group, and 203 cases in the normal control group. The diagnostic performance of the model predicted by cases based on single PLAX view and all views data was excellent: (1) in the hypertensive group, the sensitivity, specificity and AUC of models based on all views data were 97%, 89% and 0.93, respectively, while those of models based on a single PLAX view were 94%, 95%, and 0.94, respectively; (2) in the CRF group, the sensitivity, specificity and AUC of models based on all views data were 97%, 95% and 0.96, respectively, while those of models based on a single PLAX view were 97%, 89%, and 0.93, respectively; (3) in the hypothyroidism group, the sensitivity, specificity and AUC of models based on all views data were 64%, 100% and 0.82, respectively, while those of models based on a single PLAX view were 82%, 89%, and 0.86, respectively. The time required for the 3D CNN model to measure and analyze the echocardiographic videos of each subject was significantly shorter than that for the ultrasound physicians ((23.96±6.65)s vs. (958.25±266.17)s, P<0.001). Conclusions: The artificial intelligence assisted diagnosis model based on 3D CNN can extract the dynamic temporal and spatial characteristics of echocardiographic videos jointly, and quickly and efficiently identify hypertensive heart disease and cardiac changes caused by CRF and hypothyroidism.

[Construction and evaluation of a nomogram for predicting the prognosis of patients with colorectal cancer with peritoneal carcinomatosis treated with cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy]

Objectives: To construct a nomogram incorporating important prognostic factors for predicting the overall survival of patients with colorectal cancer with peritoneal metastases treated with cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC), the aim being to accurately predict such patients' survival rates. Methods: This was a retrospective observational study. Relevant clinical and follow-up data of patients with colorectal cancer with peritoneal metastases treated by CRS + HIPEC in the Department of Peritoneal Cancer Surgery, Beijing Shijitan Hospital, Capital Medical University from 2007 January to 2020 December were collected and subjected to Cox proportional regression analysis. All included patients had been diagnosed with peritoneal metastases from colorectal cancer and had no detectable distant metastases to other sites. Patients who had undergone emergency surgery because of obstruction or bleeding, or had other malignant diseases, or could not tolerate treatment because of severe comorbidities of the heart, lungs, liver or kidneys, or had been lost to follow-up, were excluded. Factors studied included: (1) basic clinicopathological characteristics; (2) details of CRS+HIPEC procedures; (3) overall survival rates; and (4) independent factors that influenced overall survival; the aim being to identify independent prognostic factors and use them to construct and validate a nomogram. The evaluation criteria used in this study were as follows. (1) Karnofsky Performance Scale (KPS) scores were used to quantitatively assess the quality of life of the study patients. The lower the score, the worse the patient's condition. (2) A peritoneal cancer index (PCI) was calculated by dividing the abdominal cavity into 13 regions, the highest score for each region being three points. The lower the score, the greater is the value of treatment. (3) Completeness of cytoreduction score (CC), where CC-0 and CC-1 denote complete eradication of tumor cells and CC-2 and CC-3 incomplete reduction of tumor cells. (4) To validate and evaluate the nomogram model, the internal validation cohort was bootstrapped 1000 times from the original data. The accuracy of prediction of the nomogram was evaluated with the consistency coefficient (C-index), and a C-index of 0.70-0.90 suggest that prediction by the model was accurate. Calibration curves were constructed to assess the conformity of predictions: the closer the predicted risk to the standard curve, the better the conformity. Results: The study cohort comprised 240 patients with peritoneal metastases from colorectal cancer who had undergone CRS+HIPEC. There were 104 women and 136 men of median age 52 years (10-79 years) and with a median preoperative KPS score of 90 points. There were 116 patients (48.3%) with PCI≤20 and 124 (51.7%) with PCI>20. Preoperative tumor markers were abnormal in 175 patients (72.9%) and normal in 38 (15.8%). HIPEC lasted 30 minutes in seven patients (2.9%), 60 minutes in 190 (79.2%), 90 minutes in 37 (15.4%), and 120 minutes in six (2.5%). There were 142 patients (59.2%) with CC scores 0-1 and 98 (40.8%) with CC scores 2-3. The incidence of Grade III to V adverse events was 21.7% (52/240). The median follow-up time is 15.3 (0.4-128.7) months. The median overall survival was 18.7 months, and the 1-, 3- and 5-year overall survival rates were 65.8%, 37.2% and 25.7%, respectively. Multivariate analysis showed that KPS score, preoperative tumor markers, CC score, and duration of HIPEC were independent prognostic factors. In the nomogram constructed with the above four variables, the predicted and actual values in the calibration curves for 1, 2 and 3-year survival rates were in good agreement, the C-index being 0.70 (95% CI: 0.65-0.75). Conclusions: Our nomogram, which was constructed with KPS score, preoperative tumor markers, CC score, and duration of HIPEC, accurately predicts the survival probability of patients with peritoneal metastases from colorectal cancer treated with cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy.

[Diagnostic value of multiparametric MRI-based models in the assessment of extra-prostatic extension of prostate cancer]

Objective: To evaluate the diagnostic value of multiparametric magnetic resonance imaging (mpMRI) based models in the assessment of extra-prostatic extension (EPE) of prostate cancer. Methods: This retrospective study included 168 consecutive men with prostate cancers [aged 48 to 82 (66.6±6.8) years] who underwent radical prostatectomy and preoperative mpMRI examinations at the First Medical Center of the PLA General Hospital from January 2021 to February 2022. According to European Society of Urogenital Radiology (ESUR) score, EPE grade and mEPE score, all cases were independently evaluated by two radiologists, with disagreement reviewed by a senior radiologist as the final result. The diagnostic performance of each MRI-based model for pathologic EPE prediction was assessed using receiver operating characteristic curve (ROC), and the differences between the corresponding area under the curve (AUC) were compared using the DeLong test. The weighted Kappa test was used to evaluate the inter-reader agreement of each MRI-based model. Results: A total of 62 (36.9%) prostate cancer patients had pathologic confirmed EPE after radical prostatectomy. The AUC of ESUR score, EPE grade and mEPE score for predicting pathologic EPE were 0.836 (95%CI: 0.771-0.888), 0.834 (95%CI: 0.769-0.887) and 0.785 (95%CI: 0.715-0.844), respectively. The AUC of ESUR score and EPE grade were both superior to that of mEPE score with significant differences (all P<0.05), while there was no significant difference between the ESUR score and EPE grade models (P=0.900). EPE grading and mEPE score had good inter-reader consistency, with weighted Kappa values of 0.65 (95%CI: 0.56-0.74) and 0.74 (95%CI: 0.64-0.84), respectively. The inter-reader consistency of ESUR score was moderate, and the weighted Kappa value was 0.52 (95%CI: 0.40-0.63). Conclusion: All MRI-based models showed good preoperative diagnostic value in predicting EPE, among which the EPE grade resulted in more reliable performance with substantial inter-reader agreement.

Roles of lncRNAs in pancreatic ductal adenocarcinoma: Diagnosis, treatment, and the development of drug resistance

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers, primarily due to its late diagnosis, high propensity to metastasis, and the development of resistance to chemo-/radiotherapy. Accumulating evidence suggests that long non-coding RNAs (lncRNAs) are intimately involved in the treatment resistance of pancreatic cancer cells via interacting with critical signaling pathways and may serve as potential diagnostic/prognostic markers or therapeutic targets in PDAC.

DATA SOURCES

We carried out a systematic review on lncRNAs-based research in the context of pancreatic cancer and presented an overview of the updated information regarding the molecular mechanisms underlying lncRNAs-modulated pancreatic cancer progression and drug resistance, together with their potential value in diagnosis, prognosis, and treatment of PDAC. Literature mining was performed in PubMed with the following keywords: long non-coding RNA, pancreatic ductal adenocarcinoma, pancreatic cancer up to January 2022. Publications relevant to the roles of lncRNAs in diagnosis, prognosis, drug resistance, and therapy of PDAC were collected and systematically reviewed.

RESULTS

LncRNAs, such as HOTAIR, HOTTIP, and PVT1, play essential roles in regulating pancreatic cancer cell proliferation, invasion, migration, and drug resistance, thus may serve as potential diagnostic/prognostic markers or therapeutic targets in PDAC. They participate in tumorigenesis mainly by targeting miRNAs, interacting with signaling molecules, and involving in the epithelial-mesenchymal transition process.

CONCLUSIONS

The functional lncRNAs play essential roles in pancreatic cancer cell proliferation, invasion, migration, and drug resistance and have potential values in diagnosis, prognostic prediction, and treatment of PDAC.

Integrated pharmacokinetics and pharmacometabolomics to reveal the synergistic mechanism of a multicomponent Chinese patent medicine, Mailuo Shutong pills against thromboangiitis obliterans

BACKGROUND

Mailuo Shutong Pills (MLST) have displayed pharmacological activity against thromboangiitis obliterans (TAO). However, the active ingredients and therapeutic mechanism of MLST against TAO remained to be further clarified.

PURPOSE

The aim of this study was to explore the active components of MLST and their synergistic mechanism against TAO by integrating pharmacokinetics (PK) and pharmacometabolomics (PM).

METHODS

TAO model rats were established by sodium laurate solution. Firstly, the efficacy of MLST was evaluated by gangrene score, blood flow velocity, and hematoxylin-eosin (H&E) staining. Secondly, PK research was conducted on bioavailable components to characterize their dynamic behaviors under TAO. Thirdly, multiple plasma and urine metabolic biomarkers for sodium laurate-induced TAO rats were found by untargeted metabolomics, and then variations in TAO-altered metabolites following MLST treatment were analyzed utilizing multivariate and bioinformatic analysis. Additionally, metabolic pathway analysis was performed using MetaboAnalyst. Finally, the dynamic link between absorbed MLST-compounds and TAO-associated endogenous metabolites was established by correlation analysis.

RESULTS

MLST significantly alleviated gangrene symptoms by improving the infiltration of inflammatory cells and blood supply in TAO rats. Significant differences in metabolic profiles were found in 17 differential metabolites in plasma and 24 in urine between Sham and TAO rats. The 10 bioavailable MLST-compounds, such as chlorogenic acid and paeoniflorin, showed positive or negative correlations with various TAO-altered metabolites related to glutamate metabolism, histidine metabolism, arachidonic acid metabolism and so on.

CONCLUSION

This study originally investigated the dynamic interaction between MLST and the biosystem, providing unique insight for disclosing the active components of MLST and their synergistic mechanisms against TAO, which also shed light on new therapeutic targets for TAO and treatment.

Tuning an efficient Escherichia coli whole-cell catalyst expressing l-pantolactone dehydrogenase for the biosynthesis of d-(-)-pantolactone

d-(-)-Pantolactone (DPL) is a key intermediate for the production of d-(+)-pantothenate (vitamin B5). Deracemization of d,l-pantolactone (D,L-PL) through oxidizing l-(+)-pantolactone (LPL) to ketopantoyl lactone (KPL) and subsequently reducing KPL to DPL is a promising route for synthesizing DPL. Herein, a newly mined l-pantolactone dehydrogenase from Rhodococcus hoagie (RhoLPLDH) was used for the oxidative dehydrogenation of LPL. To alleviate inclusion bodies formed by membrane-bound RhoLPLDH intracellular expression in E. coli, strategies involving chaperone assistance and decreasing induction temperature were used to achieve RhoLPLDH soluble expression. To enhance its activity, directed evolution and hydrophilicity-based engineering yielded increased catalytic activity and thermostability. 1M LPL was efficiently converted to KPL by engineering strain CM5 co-expressing RhoLPLDH^{L254I/V241I/I156L/F224Q/N164K} and chaperone. A "two stages in one-pot" method was employed in deracemization of 1M D,L-PL with 91.2% yield. These results demonstrated that CM5 catalyst exhibits great potential in enzyme cascade deracemization for the production of DPL.

Population total and unbound pharmacokinetics and pharmacodynamics of ciprofol and M4 in subjects with various renal functions

AIMS

The aim of this study was to develop a population pharmacokinetic (PK) model to simultaneously describe both total and unbound concentrations of ciprofol and its major glucuronide metabolite, M4, and to link it to the population pharmacodynamics (PD) model in subjects with various renal functions.

METHODS

A total of 401 and 459 pairs of total and unbound plasma concentrations of ciprofol and M4, respectively, as well as 2190 bispectral index (BIS) data from 24 Chinese subjects with various renal functions were available. Covariates that may potentially contribute to the PK and PD variability of ciprofol were screened using a stepwise procedure. The optimal ciprofol induction dosing regimen was determined by model-based simulations.

RESULTS

The PK of unbound ciprofol could best be described by a three-compartment model, while a two-compartment model could adequately describe unbound M4 PK. The concentrations of total and unbound ciprofol and M4 were linked using a linear protein binding model. The relationship between plasma concentrations of ciprofol and BIS data was best described by an inhibitory sigmoidal E_max model with a two-compartment biophase distribution compartment. Hemoglobin was the identified covariate determining the central compartment clearance of ciprofol; uric acid was a covariate affecting the central compartment clearance of M4 and protein binding rate, k_B . The included covariates had no effect on the PD of ciprofol. Simulation results indicated that the label-recommended dose regimen was adequate for anaesthesia induction.

CONCLUSIONS

The developed model fully characterized the population PK and PD profiles of ciprofol. No dose adjustment is required in patients with mild and moderate renal impairment.

Simulations of neutral beam injection and ion cyclotron resonance heating synergy in high power EAST scenarios

The EAST plasmas heated with deuterium neutral beam injection and ion cyclotron resonance heating (ICRH) have been simulated by the TRANSP code. The analysis has been conducted using the full wave solver TORIC5, the radio frequency (RF)-kick operator, and NUBEAM to model the RF heating effects on fast ion velocity distribution. In this work, we present several simulated results compared with experiments for high power EAST scenarios, indicating that the interactions between ICRH and fast ions can significantly accelerate fast ions, which are confirmed by the increased neutron yield and broadened neutron emission spectrum measurements.

Identifying quality markers of Mailuoshutong pill against thromboangiitis obliterans based on chinmedomics strategy

BACKGROUND

Mailuoshutong pill (MLSTP) is a traditional Chinese medicine (TCM) for the treatment of Thromboangiitis obliterans (TAO, Buerger's disease) which is a segmental non-atherosclerotic inflammatory occlusive disorder. However, the mechanism and quality standards of MLSTP have not been sufficiently studied.

PURPOSE

This work aims to investigate the potential mechanisms and quality markers (Q-markers) of MLSTP treating TAO based on the chinmedomics strategy.

METHODS

The therapeutical effect of MLSTP on TAO rats was evaluated by changes in body weight and clinical score, regional blood flow velocity and perfused blood vessel distribution, hematoxylin-eosin (H&E) staining, serum metabolic profile. Moreover, both endogenous metabolites and exogenous components were simultaneously detected in serum based on ultra-high performance liquid chromatography coupled with a Q Exactive hybrid quadrupole-orbitrap high resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS), and multivariate analysis was applied to identify the biomarkers, as well as the dynamic changes of metabolites were observed to explore the mechanism of action of MLSTP. In addition, the pharmacodynamic material basis were identified by correlation analysis between biomarkers and absorbed constituents. Finally, the Q-markers of MLSTP were determined according to the screening principles of Q-marker and validated the measurability.

RESULTS

MLSTP treatment alleviated disease severity of TAO, reduced inflammatory infiltration, and ameliorated vascular function. 26 potential biomarkers associated with glutamate metabolism, linoleic acid metabolism, arachidonic acid metabolism and so on were identified. Besides, 27 prototypical components were identified in serum, 16 of which were highly correlated with efficacy and could serve as the pharmacodynamic material basis of MLSTP against TAO. In addition, 7 compounds, namely, sweroside, chlorogenic acid, calycosin-7-glucoside, formononetin, paeoniflorin, liquiritigenin and 3-butylidenephthalide, were considered as potential Q-markers of MLSTP. Ultimately, the measurability of the seven Q-markers was validated by rapid identifcation and quantifcation.

CONCLUSION

This study successfully clarified the therapeutic effect and Q-markers of MLSTP by chinmedomics strategy, which is of great significance for the establishment of quality standards. Furthermore, it provides a certain reference for the screening of Q-markers in TCM prescriptions.

[Quantitative evaluation of global left ventricular myocardial work in patients with hepatitis B cirrhosis by pressure-strain loop]

Objective: To quantitatively evaluate myocardial work in patients with hepatitis B cirrhosis by using left ventricular pressure-strain loop. Methods: 70 cases with hepatitis B cirrhosis who were hospitalized in Henan Provincial People's Hospital from March to December 2020 were selected as the study group. Patients were divided into three subgroups according to the Child-Pugh score of liver cirrhosis (Child-Pugh class A, B, and C groups: 25, 25, and 20 patients, respectively). At the same time, 25 healthy volunteers were included as the control group. Global longitudinal strain (GLS), global myocardial work index (GWI), global work efficiency (GWE), global constructive work (GCW), and global wasted work (GWW) were obtained by applying pressure-strain loops. The differences were analyzed and compared among the four groups parameters. Results: Compared with the control group, the Child-Pugh class A group had decreased GLS, while Child-Pugh class B and C had decreased GLS, GWI, GWE, GCW, and increased GWW, and the differences were statistically significant (P<0.05). Compared with Child-Pugh class A group, Child-Pugh class B group had decreased GLS, GWE, and increased GWW, while Child-Pugh class C group had decreased GLS,GWI, GWE, GCW, and increased GWW, and the differences were statistically significant (P<0.05). Compared with Child-Pugh class B group, Child-Pugh class C group had decreased GLS, GWI, GWE, GCW, and increased GWW, and the differences were statistically significant (P<0.05). Conclusion: The pressure-strain loop can detect early myocardial dysfunction, and has a certain value in the diagnosis, treatment and prognosis evaluation of myocardial function changes in patients with hepatitis B cirrhosis.

Impedance matching system using triple liquid stub tuners for high-power ion cyclotron resonance heating in EAST tokamak

Ion cyclotron resonance heating (ICRH), one of the main auxiliary methods, for high-power and long-pulse plasma heating had been developed in Experimental Advanced Superconducting Tokamak (EAST). An impedance matching system, one important part of ICRH, had been developed for high-power injection and transmitter protection by reducing the reflected power from the antenna. The input impedance in the outlet of the stub tuner can be measured by voltage-current probes installed on the coaxial transmission line between the antenna and triple liquid stub tuners, and the optimum liquid levels in the stub tuners can be calculated based on the input impedance. The calculation and adjustment process of the optimum liquid levels are described comprehensively in this article. Finally, impedance matching had been achieved between two shots during EAST experiments. In the near future, a real-time impedance matching system will be developed to prevent large variations of the ICRH antenna impedance and achieve steady-state and long-pulse operation with the ICRH system.

Enabling biocatalysis in high-concentration organic cosolvent by enzyme gate engineering

Biocatalysis in high-concentration organic solvents (OSs) offers many advantages, but realizing this process remains a huge challenge. An R-selective ω-amine transaminase variant (AcATA_M2 ) exhibited high activity toward 50 g/L pro-sitagliptin ketone 1-[1-piperidinyl]-4-[2,4,5-trifluorophenyl]-1,3-butanedione (PTfpB). However, AcATA_M2 displayed unsatisfactory organic-cosolvent resistance against high-concentration dimethyl sulfoxide (DMSO), which is required to enhance the solubility of the hydrophobic substrate PTfpB. Located in the substrate-binding tunnel, enzyme gates are structural elements that undergo reversible conformational transitions, thus affecting the accessibility of the binding pocket to solvent molecules. Depending on the conformation of the enzyme gates, one can define an open or closed conformation on which the enzyme activity in OSs may depend. To enhance the DMSO resistance of AcATA_M2 , we identified the beneficial residues at the "enzyme gate" region via computational analysis, alanine scanning, and site-saturation mutagenesis. Two beneficial variants, namely, AcATA_M2 ^F56D and AcATA_M2 ^F56V , not only displayed improved enzyme activity but also exhibited enhanced DMSO resistance (the half-life value increased from 25.71 to 42.49 h under 60% DMSO). Molecular dynamic simulations revealed that the increase in DMSO resistance was mainly caused by the decrease in the number of DMSO molecules in the substrate-binding pocket. Moreover, in the kilogram-scale experiment, the conversion of 80 g/L substrate was increased from 50% (AcATA_M2 ) to 85% (M2^F56D in 40% DMSO) with a high e.e. of >99% within 24 h.

[Effect of perioperative accelerated rehabilitation management program for children with congenital spinal deformity]

Objective: To explore the perioperative therapeutic effect of enhanced recovery after surgery (ERAS) in children with congenital spinal deformity and summarize the clinical experience. Methods: Fifty-nine pediatric patients with congenital spinal deformities admitted to Beijing Children's Hospital from May 2020 to January 2021 were included in this study, and all patients underwent posterior spinal osteotomy orthopedic implant fusion with internal fixation. There were 22 males and 37 females, aged (7.4±4.1) years. Patients were divided into ERAS group (n=29) and control group (n=30) according to the management model. Patients in the ERAS group were managed with an accelerated recovery management model during the perioperative period, which mainly included: high protein diet, shortened fasting time, optimized anesthesia protocol, and multimodal analgesia. Patients in the control group received the traditional perioperative management model. The indexes of surgery, diet, pain score and laboratory tests were compared between the two groups. Results: All patients completed the surgery successfully. The mean temperature and pain scores of patients in the ERAS group were lower than those in the control group at 3 days postoperatively (P<0.05). The time to exhaustion and defecation in the ERAS group was (1.0±0.8) d and (2.5±0.9) d postoperatively, both significantly earlier than those in the control group ((3.4±0.8) d and (4.0±1.1) d) (both P<0.05). C-reactive protein was 38(8,46) mg/L in patients of the ERAS group on the day 3 postoperatively, which was significantly lower than that in the control group 47(22,93) mg/L (P=0.023). The hemoglobin level on postoperative day 3 was (110.7±9.6) g/L in the ERAS group, which was significantly higher than that in the control group ((104.5±11.4) g/L) (P=0.029). Postoperative complications occurred in 8(27.6%) and 9(30.0%) patients in the ERAS and control groups, respectively (P=1.000), with mild abdominal pain and bloating being the most common complications in both groups, most of which were not treated specifically. Conclusion: ERAS is a safe and effective perioperative management mode for children with congenital spinal deformity. Compared with the traditional method, it can significantly improve the treatment efficiency and deserve clinical application.

[Pisussion on noise exposure level measurement and risk assessment of typical posts in coal-fired power plants]

Objective: To study the group noise exposure level of typical coal-fired power plants and explore the establishment of risk assessment methods for noise exposed posts. Methods: In April 2020, 295 typical workers in 11 coal-fired power plants were selected as the study subjects. The noise exposure dose of typical posts and the proportion of exposure groups under different exposure doses were analyzed, and the risk assessment based on the dose-response relationship was conducted. Results: The exposure level of typical noise posts in coal-fired power plants was (84.24±4.10) dB (A) , and the over-standard rate was 44.07% (130/295) . The highest noise over-standard rate in main posts were desulfurization inspectors (51.52%) , followed by steam turbine inspectors (47.92%) and belt inspectors (46.32%) . Taking 30 years as an example, the incidence rate of occupational noise deafness of noise-exposed posts in coal-fired power plants was 12.30%. The position with the highest incidence rate was belt inspector (13.21%) , followed by steam turbine inspector (12.97%) , desulfurization inspectors (12.42%) , boiler inspectors (11.59%) and chemical water inspectors (6.89%) . Conclusion: The risk of noise exposure in coal-fired power plants is relatively high. Comprehensive control measures are recommended to effectively reduce the risk of noise deafness.

Efficient enzymatic synthesis of L-ascorbyl palmitate using Candida antarctica lipase B-embedded metal-organic framework

The Candida antarctica lipase B (CALB) was embedded in the metal-organic framework, zeolitic imidazolate framework-8 (ZIF-8), and applied in the enzymatic synthesis of L-ascorbic acid palmitate (ASP) for the first time. The obtained CALB@ZIF-8 achieved the enzyme loading of 80 mg g^-1 with 11.3 U g^-1 (dry weight) unit activity, 59.8% activity recovery, and 92.7% immobilization yield. Under the optimal condition, ASP was synthesized with over 75.9% conversion of L-ascorbic acid in a 10-batch reaction. Continuous synthesis of ASP was subsequently performed in a packed bed bioreactor with an outstanding average space-time yield of 58.1 g L^-1  h^-1 , which was higher than ever reported continuous ASP biosynthesis reactions.

Diversity of cultivable endophytic fungi in two Rubia plants and their potential for production of anti-tumour Rubiaceae-type cyclopeptides

Rubia plants are one of the most important plant resources possessing significant commercial and medicinal values. Plant endophytes could benefit their host plants in different ways. Rubiaceae-type cyclopeptides (RAs), mainly isolated from Rubia plants, have attracted considerable attentions for their distinctive bicyclic structures and significant antitumor activities, but their contents in plants are low. The aim of this study is to investigate the diversity of endophytic fungi in Rubia plants and their potential for production of RAs. In this work, 143 endophytic fungi isolates were obtained from two Rubia plants. Phylogenetic analysis was performed based on the ITS rDNA sequences, and the isolates were classified into 29 genera. Among them, four endophytic fungal strains were found to produce anti-tumour RAs by LC-MS/MS analysis. This work successfully provides valuable knowledges of endophytic fungi microbiome in Rubia plants for agricultural and industrial applications, and exploits a new environmental-friendly resource of RAs.

[The value of spleen density in predicting prognosis of patients with gastric cancer after curative gastrectomy]

Objective: To investigate the value of spleen density in predicting the prognosis of patients with gastric cancer after radical gastrectomy. Methods: A total of 415 patients with gastric cancer who underwent radical resection in the Department of General Surgery, Affiliated Cancer Hospital of Zhengzhou University from January 2012 to December 2015 were retrospectively analyzed. Of the patients, there were 295 males and 120 femles with a median age of 59 years (range 28-83 years). The patients were divided into diffuse decreased spleen density group (DROSD) (spleen density≤43.0 HU, n=118) and non-diffuse decreased spleen density group (N-DROSD) (spleen density>43.0 HU, n=297) according to the density of spleen detected by computed tomography (CT). The receiver operating characteristic (ROC) curve was used to identify the checkpoint of spleen density in predicting the recurrence of the gastric cancer in those patients. The relationship with clinicopathological factors and prognosis in the two groups were further analyzed. Results: The optimal critical value of spleen density for predicting postoperative recurrence of gastric cancer was 43.0 HU, the area under the curve of ROC was 0.608, and the sensitivity and specificity was 84.9% and 40.4%, respectively. Spleen density was related to albumin, hemoglobin, neutrophil lymphocyte ratio (NLR) and tumor diameter in patients with gastric cancer (all P<0.05). The 5-year disease-free survival rate and 5-year disease-specific survival rate of all the patients was 45.5% and 50.1%, respectively. Univariate survival analysis showed that age, NLR, PLR, tumor location, tumor diameter, Lauren classification, TNM stage, nerve invasion, vascular invasion, DROSD and adjuvant chemotherapy were all related to the 5-year disease-free survival rate (all P<0.05); Age, NLR, tumor location, tumor diameter, Lauren classification, TNM stage, nerve invasion, vascular invasion, DROSD and adjuvant chemotherapy were all related to the 5-year disease-specific survival rate (all P<0.05). Multivariate survival analysis showed that high NLR level (HR=1.501, 95%CI: 1.136-1.984), late TNM stage (HR=2.559, 95%CI: 1.850-3.539), DROSD (HR=2.093, 95%CI: 1.571-2.788) and no adjuvant chemotherapy (HR=1.583, 95%CI: 1.204-2.083) were independent risk factor for the 5-year disease-free survival rate (all P<0.05). Late TNM stage (HR=1.938, 95%CI: 1.395-2.692), DROSD (HR=1.566, 95%CI: 1.180-2.078) and no adjuvant chemotherapy (HR=1.336, 95%CI: 1.016-1.758) were independent risk factors for the 5-year disease-free survival rate (all P<0.05). For stage Ⅰ patients, the 5-year disease-free survival rates of DROSD group and N-DROSD group was 78.6% and 83.7%, respectively; and the 5-year disease-specific survival rates was 85.7% and 89.8%, respectively (both P>0.05). For stage Ⅱ and Ⅲ patients, the 5-year disease-free survival rates of DROSD group and N-DROSD group was 15.4% and 48.8%, respectively, and the 5-year disease-specific survival rates was 17.3% and 54.0%, respectively (all P<0.001). Conclusion: As an imaging evaluation method, spleen density is a new tool, which can be used as a prognostic indicator for gastric cancer patients.

[Study on metabolic dynamics,metabolic enzyme phenotype and species difference of hepatic and intestinal microsome of psoralidin]

This study aims to investigate metabolic activities of psoralidin in human liver microsomes( HLM) and intestinal microsomes( HIM),and to identify cytochrome P450 enzymes( CYPs) and UDP-glucuronosyl transferases( UGTs) involved in psoralidin metabolism as well as species differences in the in vitro metabolism of psoralen. First,after incubation serial of psoralidin solutions with nicotinamide adenine dinucleotide phosphate( NADPH) or uridine 5&apos;-diphosphate-glucuronic acid( UDPGA)-supplemented HLM or HIM,two oxidic products( M1 and M2) and two conjugated glucuronides( G1 and G2) were produced in HLM-mediated incubation system,while only M1 and G1 were detected in HIM-supplemented system. The CLintfor M1 in HLM and HIM were 104. 3,and57. 6 μL·min~(-1)·mg~(-1),respectively,while those for G1 were 543. 3,and 75. 9 μL·min~(-1)·mg~(-1),respectively. Furthermore,reaction phenotyping was performed to identify the main contributors to psoralidin metabolism after incubation of psoralidin with NADPH-supplemented twelve CYP isozymes( or UDPGA-supplemented twelve UGT enzymes),respectively. The results showed that CYP1 A1( 39. 5 μL·min~(-1)·mg~(-1)),CYP2 C8( 88. 0 μL·min~(-1)·mg~(-1)),CYP2 C19( 166. 7 μL·min~(-1)·mg~(-1)),and CYP2 D6( 9. 1 μL·min~(-1)·mg~(-1)) were identified as the main CYP isoforms for M1,whereas CYP2 C19( 42. 0 μL·min~(-1)·mg~(-1)) participated more in producing M2. In addition,UGT1 A1( 1 184. 4 μL·min~(-1)·mg~(-1)),UGT1 A7( 922. 8 μL·min~(-1)·mg~(-1)),UGT1 A8( 133. 0 μL·min~(-1)·mg~(-1)),UGT1 A9( 348. 6 μL·min~(-1)·mg~(-1)) and UGT2 B7( 118. 7 μL·min~(-1)·mg~(-1)) played important roles in the generation of G1,while UGT1 A9( 111. 3 μL·min~(-1)·mg~(-1)) was regarded as the key UGT isozyme for G2. Moreover,different concentrations of psoralidin were incubated with monkey liver microsomes( MkLM),rat liver microsomes( RLM),mice liver microsomes( MLM),dog liver microsomes( DLM) and mini-pig liver microsomes( MpLM),respectively. The obtained CLintwere used to evaluate the species differences.Phase Ⅰ metabolism and glucuronidation of psoralidinby liver microsomes showed significant species differences. In general,psoralidin underwent efficient hepatic and intestinal metabolisms. CYP1 A1,CYP2 C8,CYP2 C19,CYP2 D6 and UGT1 A1,UGT1 A7,UGT1 A8,UGT1 A9,UGT2 B7 were identified as the main contributors responsible for phase Ⅰ metabolism and glucuronidation,respectively. Rat and mini-pig were considered as the appropriate model animals to investigate phase Ⅰ metabolism and glucuronidation,respectively.

[Clinical analysis of 9 cases of a novel stent assisted intestinal bypass for preventing anastomotic leakage in laparoscopic assisted radical resection of rectal cancer]

Objective: To examine the safety and effectiveness of a novel stent assisted intestinal bypass for preventing anastomotic leakage in laparoscopic assisted radical resection of rectal cancer. Methods: The clinical data of 9 patients with rectal cancer who underwent laparoscopic radical resection and stent assisted intestinal bypass from September 2019 to June 2020 at the Department of Anus & Intestine Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University were retrospectively analyzed. There were 6 males and 3 females, aged (62.1±6.8) years (range: 53 to 75 years), underwent laparoscopic assisted radical resection of rectal cancer and stent assisted intestinal bypass. A degradable diverting stent was placed at the end of the ileum, and a drainage tube was placed at the proximal end of the stent to bypass the intestinal contents. After operation, the patients were given a diet with less residue. From the 14^th day after operation, abdomen X-ray films were taken every 5 to 7 days to observe the destination of the stent dynamically. When the stent was observed to be disintegrated into pieces, the drainage tube was clamped for 3 days to observe any side effects before the tube was removed. The operation time, the time of removing the bypass tube and the total hospital stay were recorded. Results: Laparoscopic assisted radical resection of rectal cancer and stent assisted intestinal bypass were successfully performed in all patients. The operation time was (230.4±48.0) minutes (range: 150 to 318 minutes), and the time of removing shunt tube was (28.8±4.6) days (range: 22 to 34 days). The duration of hospitalization was (21.0±8.6) days (range: 9 to 34 days). Postoperative pathological examination showed 7 cases of moderately differentiated adenocarcinoma, 1 case of moderately well differentiated adenocarcinoma and 1 case of mucinous adenocarcinoma. There were 2 cases of T1, 4 cases of T2 and 3 cases of T3. The number of lymph node dissection was 13.4±3.5 (range: 6 to 18), 3 cases were positive and 6 cases were negative. The post-operation follow-up time was 6 to 16 months, no anastomotic leakage or stenosis was found. Conclusion: Stent assisted intestinal bypass for the prevention of anastomotic leakage in laparoscopic assisted radical resection of rectal cancer is safe and feasible, and shows good short-term effect.

[Effects of duodenal ligation on gastroesophageal reflux and bleomycin-induced pulmonary fibrosis in rats]

Objective: To investigate the effects of duodenal ligation on gastroesophageal reflux and bleomycin-induced pulmonary fibrosis in rats. Methods: Wistar rats were randomized into the control (Ctrl) group, bleomycin (BLM) group, duodenal ligation (GER) group and duodenal ligation plus bleomycin treatment (BLM+GER) group. At day 0 (d0), duodenum ligation was performed in the GER and the BLM+GER group through an open-abdomen surgery at 1.0 cm below the pylorus by about 30% of the circumference. Meanwhile, sham operation was performed in the Ctrl and the BLM group with similar procedures to the above without ligation of the duodenum. At day 14, bleomycin solution (5 mg/kg, for the BLM and BLM+GER groups) or saline (for the Ctrl and GER groups) was intratracheally instilled. Rats were sacrificed at d28 or at d42. HE, Masson's trichrome or TUNEL staining was performed on lung sections of the groups. The levels of hyrdoxyproline (HYP) or malondialdehyde (MDA) were measured respectively by alkaline hydrolysis or thiobarbituric acid colorimetry. The levels of pepsin and cytokines in bronchoalveolar lavage fluid (BALF) samples were assessed by ELISA. Western blot or RT-PCR was used to quantify relative lung expression of proteins or mRNA, respectively. Results: Lungs of the GER group rats were presented with mild inflammatory cell infiltration. Alveolitis and lung fibrosis was prominent in the BLM group but even more severe in the BLM+GER group. Of the Ctrl, GER, BLM and BLM+GER group, the average numbers of apoptotic cells per each magnified field (×200) on d28 lung sections was (5.6±3.0), (6.4±5.3), (15.4±5.3) and (18.4±9.1), respectively (P=0.008); the proportion (%) of blue-stained area under Masson's trichrome at d42 was (21.5±2.8), (23.4±2.5), (34.0±5.8) and (41.3±2.9) (P<0.05); the HYP contents (mg/L) at d42 of each group was (0.77±0.01), (1.26±0.01), (2.02±0.01) and (2.39±0.01) (P<0.01); the BALF levels of MDA (μmol/L) at d42 were (0.51±0.09), (0.87±0.12), (1.40±0.31) and (1.71±0.12) (P<0.001), and differences of these three indices at d42 reached statistical significance when comparing the Ctrl or GER group with the BLM or BLM+GER group (all P<0.05). The levels of pepsin, pH, interleukin (IL)-1β, transforming growth factor (TGF)-β1 and HYP at d28 and d42 were statistically different between the GER group and the Ctrl group (all P<0.05). As compared with the BLM group, the values of TGF-β1, HYP, p-Smad3, vimentin, p-ERK1/2 and cleaved caspase-3 at d28 and d42 were different in the BLM+GER group (all P<0.05). At both d28 and d42, the BALF levels of pepsin and pH were statistically different between the BLM and the Ctrl group, or between the BLM+GER group and the GER group (all P<0.05). Conclusions: Gastroesophageal reflux is induced through duodenal ligation, which activates proinflammatory and profibrotic signals in the lungs and significantly aggravates bleomycin-induced lung injury and fibrosis. In addition, pulmonary fibrosis may induce or worsen the extent of reflux.

[The clinical predictors for the prognosis of patients with osteosarcoma]

Osteosarcoma is a kind of primary malignant tumor of bone originated from mesenchymal tissue, which mainly occurs in children and adolescents, and presents the characteristics of high malignancy, rapid growth, early metastasis and poor prognosis. Currently, most of the studies at home and abroad mainly focused on therapeutic procedures. However, reliable prediction indices or evaluation systems are also pivotal for monitoring disease change, guiding treatment and evaluating prognosis. Multiple clinical predictors have been reported to be related to the prognosis of osteosarcoma, which can be roughly divided into 9 categories according to their characteristics. Each kind of predictor owns its inherent advantage and disadvantage, and full understanding of them and their characteristics can be helpful to improve the prognosis of osteosarcoma.

Outcome of scleral buckling with or without gas tamponade for recurrent retinal detachment in post-vitrectomy eyes

Background

Treatment of recurrent retinal detachment (re-RD) following vitrectomy (post-gas/air tamponade and post-silicone oil removal) is challenging. Previously reported treatment is commonly revision pars plana vitrectomy (PPV) combined with tamponade, which is invasive and a burden both economically and emotionally when compared with scleral buckling (SB). The purpose of this study is to report anatomical and functional outcomes of SB with or without gas tamponade in eyes with recurrent retinal detachment (re-RD) that previously underwent PPV at least once.

Methods

We retrospectively reviewed the medical records of 14 patients (14 eyes) who underwent PPV at least once and were treated with SB after re-RD. Preoperative characteristics, intraoperative complications, and postoperative data were assessed. The final anatomical and functional outcomes were analyzed.

Results

The original PPV was performed for primary rhegmatogenous retinal detachment in 11 eyes, macular hole retinal detachment in 2 eyes, and myopic foveoschisis in 1 eye. Previously, 3 eyes underwent one PPV with gas tamponade, and the remaining 11 (79%) eyes underwent 2–5 operations. Seven eyes underwent the procedure with gas injection. At the last follow-up, 13 eyes achieved total retinal attachment and 1 eye had re-RD. The postoperative intraocular pressure was within the normal range, except in 1 eye (6 mmHg). The finest postoperative best-corrected visual acuity (BCVA) was 20/25. There was a significant improvement in BCVA from 20/160 ± 20/63 at baseline to 20/80 ± 20/50 at the last visit in the 13 successfully treated eyes (P = 0.025).

Conclusions

SB can be effective for re-RD after PPV in specific cases.

[Postoperative complications and their influence on the prognosis factors in gastric cancer patients receiving neoadjuvant treatment]

Objective: To investigate postoperative complications of patients undergoing neoadjuvant therapy followed by radical gastrectomy, and to analyze their influence on the prognosis. Methods: A retrospective case-control study was used. Case inclusion criteria: (1) gastric adenocarcinoma confirmed by histopathology; (2) preoperative imaging examination showed no distant metastasis or peritoneal dissemination; (3) undergoing radical gastrectomy and D2 lymph node dissection after neoadjuvant therapy; (4) complete clinicopathological and follow-up data. According to the above criteria, clinical data of 490 gastric cancer patients who underwent radical gastrectomy in the Cancer Hospital of Chinese Academy of Medical Sciences, Peking Union Medical College from January 2008 to December 2018 were retrospectively collected, including 358 males and 132 females with mean age of (55.0±10.6) years. Neoadjuvant chemotherapy regimens included SOX (S-1+ oxaliplatin, n=151), XELOX (capecitabine+oxaliplatin, n=155), FLOT (docetaxel+oxaliplatin+fluorouracil, n=66), and DOS (docetaxel+ oxaliplatin+S-1, n=68). Preoperative concurrent chemoradiotherapy was performed in 100 patients. SOX regimen was used for 2-4 cycles as induction chemotherapy plus concurrent chemoradiotherapy (3D IMRT+S-1). Postoperative complications were defined as surgery-related complications, mainly including hemorrhage, anastomotic leakage, obstruction, anastomotic stenosis, pulmonary infection, abdominal infection, etc. Postoperative complications were graded according to Clavien-Dindo classification. Log-rank test and Cox regression model were used for univanriate multivariate prognostic analysis, respectively. Results: A total of 101 complications ocaured after operation in 87 (17.8%) patients, including 29 cases of major complications (Clavien-Dindo III to V), and 58 cases of minor complications (Clavien-Dindo I to II). Multivariate analysis showed that age > 65 years (HR=3.077, 95% CI: 1.827-5.184, P<0.001) and total gastrectomy (HR=1.735, 95% CI: 1.069-2.814, P=0.026) were independent risk factors for postoperative complications in patients with gastric cancer undergoing neoadjuvant therapy and radical gastrectomy (both P<0.05). The follow-up period was 0.7 to 131.8 months (median 21.5 months), and the 5-year overall survival rate was 47.4%. The 5-year overall survival rates of the complication group (87 cases) and the non-complication group (403 cases) were 33.2% and 50.9%, respectively (P=0.001). Multivariate analysis showed that age (HR=1.906, 95% CI: 1.248-2.913, P=0.003), ypTNM II to III stage (II stage: HR=5.853, 95% CI: 1.778-19.260, P=0.004; III stage: HR=10.800, 95% CI: 3.411-34.189, P<0.001), surgery time>3.5 h (HR=1.492, 95% CI: 1.095-2.033, P=0.011), total gastrectomy (HR=1.657, 95% CI: 1.216-2.257, P=0.001) and postoperative complications (HR=1.614, 95% CI: 1.125-2.315, P=0.009) were independent risk factors for prognosis, and postoperative adjuvant therapy (HR=0.578, 95% CI: 0.421-0.794, P=0.001) was an independent protective factor for prognosis. Conclusions: The occurrence of postoperative complications in gastric cancer patients undergoing neoadjuvant therapy is closely related to the age of the patients and the range of surgical resection. It is beneficial to improve the prognosis for these patients by paying more attention to the prevention of postoperative complications and the reinforcement of postoperative adjuvant therapy.

[Therapeutic effect of nivolumab on non-small-cell lung cancer patients with brain metastases: a retrospective study]

Objective: To preliminarily explore the treatment effect of nivolumab on Chinese non-small-cell lung cancer (NSCLC) patients with brain metastases, and further enrich the evidences of programmed death-ligand 1 (PD-1) monoclonal antibody in the treatment of NSCLC patients with brain metastases. Methods: The clinical and pathological data of 22 NSCLC patients with brain metastases treated with nivolumab were collected. The electronic imaging data were collected to confirm the treatment effect and time point of disease progression, and the survival data of the patients were obtained through follow-up. Results: Twenty-one patients were evaluated for the intracranial treatment effect. The intracerebral objective response rate (IORR) was 28.6%, the intracranial disease control rate (IDCR) was 47.6%. The median intracranial progression-free-survival (iPFS) of all the 22 patients was 5.2 months. Both the 1-year and 2-year survival rates were 56.7%. Conclusions: The treatment effect of PD-1 monoclonal antibody on NSCLC patients with brain metastases is similar as those without brain metastases.

[Application of carbon nanoparticles labeled node staining in D2 radical resection of gastric cancer with neoadjuvant chemotherapy]

Objective: To explore the application value of carbon nanoparticles labeled node staining in D2 radical resection of gastric cancer with neoadjuvant chemotherapy. Methods: The retrospective cohort study was conducted. The clinicopathological data of 82 patients with gastric cancer who were admitted to Henan Tumor Hospital from April 2016 to April 2019 were collected. 38 patients who used carbon nanoparticles labeled node staining were in the observation group, while other 44 patients were in the control group. Data analysis including the operation and results of harvested of lymph nodes. Results: All patients successfully completed the operation.Thirty-eight patients successfully completed the injection of carbon nanoparticles. Surgery: observation group operating time was (150±28) min, intraoperative blood loss was (207±121) ml, group operating time was (140±23) min, intraoperative blood loss was (256±182) ml. There was no statistically significant difference between the two groups. Detection of Lymph node: A total of 1 260 lymph nodes were detected in the observation group and 981 in the control group. In the observation group, the mean lymph node sorting time was (17.2±3.3) min, the average number of harvested lymph node was 33.2±10.4, the number of the first station of lymph node was 19.8±5.3, the second station of lymph node was 13.4±6.4, the number of harvested small node(<5 mm) was 673, the positive lymph nodes was 13(range,1-31). They were all higher than those in the control group, which were (20.6±4.4)min,22.3±6.6, 12.6±4.1, 9.7±3.2,432,6 (range,1-13) , respectively. The difference between the two groups was statistically significant (P<0.05). The metastasis rate was 19.1% (241/1 260) in observation group and 16.5%(162/981) in the control group. The difference was no statistical(P>0.05). The rate of black -dyed harvested lymph node was 54.4%(686/1 260) in carbon nanoparticles group. Conclusions: The application of carbon nanoparticles labeled node staining in D2 radical resection of gastric cancer with neoadjuvant chemotherapy is feasible and safe. It can increase the number of lymph nodes detected, which is beneficial to the evaluation of chemotherapy effect and prognosis of patients.

Deciphering the Relationship Between the Trough Concentration of Posaconazole and Its Efficacy and Safety in Chinese Patients With Hematological Disorders

Posaconazole (PCZ) is effective in preventing and salvage treatment invasive fungal infections in patients with hematologic disorders. However, PCZ displays highly variable individual pharmacokinetics affecting its efficacy and safety. To investigate the correlation between PCZ concentration and efficacy and safety, the following key influencing factors were explored. A total of 285 trough plasma concentrations (C_min) of 81 Chinese patients receiving PCZ oral suspension for prophylaxis or treatment of invasive fungal infections were collected in this study. The relationships between C_min values and clinical response and hepatotoxicity were investigated as well as the incidence of clinical response under different C_min values of PCZ with a logistic regression model. The concentration of PCZ showed remarkable differences among patients with haematologic disorders. PCZ C_min values of 0.76 and 1.0 µg/mL were both associated with an over 80% probability of successful response to prophylaxis and treatment of fungal infections, respectively. No association between C_min values and hepatotoxicity was noted (P > 0.05). Gender, albumin, and co-administration of proton pump inhibitor (PPI) were identified as independent factors influencing PCZ C_min by multiple linear regression analysis. Furthermore, patients’ C-reactive protein (CRP), albumin, and co-administration of PPI exhibited significant effects on the therapeutic window of patients receiving PCZ for prophylaxis. The plasma concentration is closely associated with therapeutic efficacy of PCZ. It is necessary to adjust the dosing regimens based on PCZ C_min to obtain an optimal therapeutic response.

Efficient Synthesis of Sugar Alcohols under Mild Conditions Using a Novel Sugar-Selective Hydrogenation Catalyst Based on Ruthenium Valence Regulation

Sugar alcohols are the prominent alternatives of sugars in food, medical, and health industries. The ruthenium supported on multiwalled carbon nanotubes (Ru/MWCNTs) catalysts were prepared based on the Ru valence regulation strategy and applied for selective sugar hydrogenation to prepare various sugar alcohols including xylitol, arabinitol, sorbitol, mannitol, and galactitol for the first time, with high selectivity (>99.0%) and yield (>98.0%) under mild conditions (≤110 °C, 3.0 MPa H₂ pressure). The hydrogenation reaction of xylose was further optimized and under mild conditions (100 °C, 3.0 MPa H₂ pressure, and 500 rpm), which were lower than ever reported for high efficient synthesis of xylitol, 99.8% xylose conversion and 99.0% xylitol yield were achieved after 120 min of reaction.

Performance of BAC for DBPs precursors' removal for one year with micro-polluted lake water in East-China

Effectiveness of biological activated carbon (BAC) filter in removing disinfection byproducts (DBPs) precursors of micro-polluted lake water for one year was conducted. The formation potential (FP) of DBPs (trihalomethanes (THMs), haloacetic acids (HAAs) and Nitrosamines (NAs)), dissolved organic carbon (DOC), molecular weight (MW) distribution and excitation emission matrix fluorescence (EEM) of dissolved organic material (DOM) in the influent and effluent of BAC were determined. The results indicated that the removal efficiency (RE) of DOC ranged from 42.9-28.3%. Neither virgin GAC nor long-term operated BAC could efficiently dispose of THMs and HAAs precursors (RE from 35.2-18.8%, from 42 to 8.4%, respectively), however, BAC still showed good ability in removal of NAs precursors after a year operation, of which RE just dropped from 81.7-69.6%. There was strong correlation between RE of NAs precursors and DOC with small MW (<0.5 kDa). The removal of HAAs precursors showed relatively close relation to aromatic protein-like components and soluble microbial pollutants (SMPs). Weak direct relationship was found between the water quality parameters and THMs precursors.

[The effect of booster dose vaccination 21- to 32-years after primary vaccination with hepatitis B vaccine in the population born from 1986 to 1996 in Zhengding County of Hebei Province]

Objective: Aanalysis the effect of booster one dose of hepatitis B vaccine after 21-32 years of primary immunization in Zhengding Country of Hebei Province. Methods: A total of 322 participants who were born between 1986 and 1996, received a full course of primary vaccination with plasma-derived hepatitis B vaccine (HepB), had no experience with booster vaccination, were HBsAg, anti-HBcnegative, had anti-HBs<10 mIU/ml, completed the booster and had laboratory results were enrolled between August 2017 to February 2018. A simple random method was uesd to randomly assigned 322 subjects to two groups, receiving a booster dose of HepB derived from either Saccharomyces cerevisiae ［HepB (SC), (151 cases)］ or Chinese hamster ovary-derived HepB ［HepB (CHO), (171 cases)］, the dose was 20 μg. Blood samples were collected 30 days after boosting and quantitatively tested for the geometric mean concentration (GMC) of anti-HBs to assess immunological effect. The related influencing factors of GMC and seroconversion rates of anti-HBs were analyzed by multiple linear regression and multivariate logistic regression models. Results: The 266 subjects (82.61%) had anti-HBs≥ 10 mIU/ml, and GMC was (131.63±12.94) mIU/ml.The seroconversion rates of anti-HBs in the anti-HBs<2.5 mIU/ml group and 2.5-10 mIU/ml group were 74.54% (161 cases) and 99.06% (105 cases), respectively (P<0.001).The seroconversion rates of anti-HBs after one dose of HepB (CHO) was higher than that of one dose of HepB (SC), the seroconversion rates were 87.13% (149 cases) and 77.48% (117 cases), respectively (P=0.023). Participants boostered with HepB (CHO) was the factor influencing the effect of strengthening immunization compared with boostered with HepB (SC), and OR (95%CI) was 1.91 (1.02-3.56) (P=0.042).Compared with anti-HBs<2.5 mIU/ml, prebooster anti-HBs was between 2.5 mIU/ml and 10 mIU/ml was the related factor of seroconversion rates of anti-HBs after booster immunization, and OR (95%CI) was 36.15 (4.91-266.02) (P<0.001). Conclusion: Participants boostered withone dose of HepB had a good immune response. Pre-booster anti-HBs concentration and a variety of vaccine were related factors of immune response.

[Thinking of the application of membrane anatomy in gastric cancer surgery after neoadjuvant therapy]

The standard treatment for advanced gastric cancer remains surgery-based comprehensive treatment. The D2 radical surgery has made outstanding contributions to the standarlization of gastric cancer surgery, which has improved patients' prognosis and quality of life. In recent years, neoadjuvant chemotherapy has achieved a certain effect on the treatment of advanced gastric cancer. With the continuous development of the concept of membrane anatomy in gastric cancer surgery, new surgical challenges have also been raised. For patients after neoadjuvant therapy, there is heated controversy in the possibility of completing radical gastrectomy with membrane anatomical concept for gastric cancer. We believe that if neoadjuvant therapy pushes mesenteric cancer cell back into the mesentery, theoretically membrane anatomy combined with neoadjuvant therapy is beneficial to the treatment efficacy of advanced gastric cancer. However, membrane anatomy has two important problems when combined with neoadjuvant therapy: (1) After neoadjuvant chemotherapy, there are varying degrees of edema around the stomach tissue, which will affect the visualization of anatomic planes. In addition, because the patients' coagulation function is damaged to a certain extent, it is difficult to avoid bleeding or minimize bleeding during the operation. Therefore, it is still controversial whether the patients with gastric cancer after neoadjuvant chemotherapy can undergo radical gastrectomy with membrane anatomy. (2) For patients with complete pathological remission, whether to obtain the maximum rate of pathological remission through intensive neoadjuvant therapy, or to obtain the survival benefit of patients with membrane anatomy surgery in clinic is still controversial. Faced with these confusions, multi-center clinical researches on the application of membrane anatomy surgery after neoadjuvant therapy is the only solution.

Efficient production of an ezetimibe intermediate using carbonyl reductase coupled with glucose dehydrogenase

Ezetimibe is a top-selling hypolipidemic drug for the treatment of cardiovascular diseases. Biosynthesis of (4S)-3-[(5S)-5-(4-fluorophenyl)-5-hydroxypentanoyl]-4-phenyl-1,3-oxazolidin-2-one ((S)-ET-5) using carbonyl reductase has shown advantages including high catalytic efficiency, excellent stereoselectivity, mild reaction conditions, and environmental friendness, and was considered as the key step for ezetimibe production. The regeneration efficiency of the cofactor, nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) is one of the main restricted factor. Recombinant Escherichia coli strain (smCR125) coexpressing carbonyl reductase (CR125) and glucose dehydrogenase were successfully constructed and applied for the production of (S)-ET-5 for the first time. Without extra addition of the coenzyme NADPH, the yield of 99.8% and the enantiomeric excess (e.e.) of 99.9% were achieved under ET-4 concentration of 200 g/L. Using a substrate fed-batch strategy, under the optimal conditions, the substrate ET-4 concentration was increased to 250 g/L with the yield of 98.9% and the e.e. of 99.9% after 12 hr reaction. The space-time yield of 494.5 g L^-1 d^-1 and the space-time yield per gram biocatalyst of 24.7 g L^-1 d^-1 g^-1 DCW were achieved, which were higher than ever reported for the biosynthesis of the ezetimibe intermediate.

[Analysis on post-marketing effectiveness and immunogenicity of enterovirus-A71 vaccine]

Objective: To analyze the effectiveness and immunogenicity of enterovirus-A71(EV-A71) vaccine in immunization program. Methods: A cohort study was conducted in immunization clinics in Jing'an district in Shanghai from October to December 2017. Children who received EV-A71 vaccine based on a 2-dose schedule (on day 0 and day 30) were enrolled as vaccine group and those who received no EV-A71 vaccine were enrolled as control group. After 1-year follow-up, the effectiveness and neutralizing antibody level and the positive results of antibody immunogenicity in vaccine group were analyzed. Results: A total of 3 018 children aged 8-20 months were enrolled, in whom 1 211 were in vaccine group and 1 807 were in control group. The vaccine effectiveness was 100% against EV-A71-associated hand, foot, and mouth disease (HFMD) indicated by 1 year follow-up (95%CI: -66.99%-100.00%). The geometric mean titer of neutralizing antibody (GMT) was 41.76 (95%CI: 35.60-49.34) at day 60 and 28.44(95%CI: 23.59-34.54) at day 365 in 124 children in vaccine group. Conclusions: In children, EV-A71 vaccine elicited EV-A71-specific immune response. Less EV-A71-associated HFMD cases have been observed, further observation is needed.