In the aromatic amino acid biosynthetic pathway 3-dehydroshikimate (DHS) is a key intermediate. As a potent antioxidant and important feedstock for producing a variety of important industrial chemicals, such as adipate and vanillin, DHS is of great commercial value. Here, in this study, we investigated the effect of the co-expression of aroFFBR (3-deoxy-D-arabino-heptulosonate 7-phosphate synthase mutant with tyrosine feedback-inhibition resistance) and tktA (Transketolase A) at different copy number on the production of DHS. The increased copy number of aroFFBR and tktA would enhance the production of DHS by the fold of 2.93. In order to further improve the production of DHS, we disrupted the key genes in by-product pathways of the parent strain Escherichia coli AB2834. The triple knockout strain of ldhA, ackA-pta and adhE would further increase the production of DHS. The titer of DHS in shake flask reached 1.83 g/L, 5.7-fold higher than that of the parent strain E. coli AB2834. In 5-L fed-batch fermentation, the metabolically engineered strain produced 25.48 g/L DHS after 62 h. Metabolically engineered E. coli has the potential to further improve the production of DHS.
3-Deoxy-7-Phosphoheptulonate Synthase ; genetics ; Amino Acids, Aromatic ; biosynthesis ; Biosynthetic Pathways ; Escherichia coli ; genetics ; metabolism ; Fermentation ; Metabolic Engineering ; Shikimic Acid ; analogs & derivatives ; metabolism ; Transketolase ; genetics

Gluconobacter oxydans is known to oxidize glucose to gluconic acid (GA), and subsequently, to 2-keto-gluconic acid (2KGA) and 5-keto-gluconic acid (5KGA), while 5KGA can be converted to L-(+)-tartaric acid. In order to increase the production of 5KGA, Gluconobacter oxydans HGI-1 that converts GA to 5KGA exclusively was chosen in this study, and effects of carbon sources (lactose, maltose, sucrose, amylum and glucose) and nitrogen sources (yeast extract, fish meal, corn steep liquor, soybean meal and cotton-seed meal) on 5KGA production were investigated. Results of experiment in 500 mL shake-flask show that the highest yield of 5KGA (98.20 g/L) was obtained using 100 g/L glucose as carbon source. 5KGA reached 100.20 g/L, 109.10 g/L, 99.83 g/L with yeast extract, fish meal and corn steep liquor as nitrogen source respectively, among which the optimal nitrogen source was fish meal. The yield of 5KGA by corn steep liquor is slightly lower than that by yeast extract. For the economic reason, corn steep liquor was selected as nitrogen source and scaled up to 5 L stirred-tank fermentor, and the final concentration of 5KGA reached 93.80 g/L, with its maximum volumetric productivity of 3.48 g/(L x h) and average volumetric productivity of 1.56 g/(L x h). The result obtained in this study showed that carbon and nitrogen sourses for large-scale production of 5KGA by Gluconobacter oxydans HGI-1 were glucose and corn steep liquor, respectively, and the available glucose almost completely (85.93%) into 5KGA.
Bioreactors ; Carbon ; chemistry ; Culture Media ; chemistry ; Fermentation ; Gluconates ; metabolism ; Gluconobacter oxydans ; metabolism ; Industrial Microbiology ; Nitrogen ; chemistry

Rhamnolipid biosurfactant is mainly produced by Pseudomonas aeruginosa that is the opportunistic pathogenic strain and not suitable for future industrial development. In order to develop a relatively safe microbial strain for the production of rhamnolipid biosurfactant, we constructed engineered Escherichia coli strains for rhamnolipid production by expressing different copy numbers of rhamnosyltransferase (rhlAB) gene with the constitutive synthetic promoters of different strengths in E. coli ATCC 8739. We further studied the combinatorial regulation of rhlAB gene and rhaBDAC gene cluster for dTDP-1-rhamnose biosynthesis with different synthetic promoters, and obtained the best engineered strain-E. coli TIB-RAB226. Through the optimization of culture temperature, the titer of rhamnolipd reached 124.3 mg/L, 1.17 fold higher than that under the original condition. Fed-batch fermentation further improved the production of rhamnolipid and the titer reached the highest 209.2 mg/L within 12 h. High performance liquid chromatography-mass spectrometry (LC-MS) analysis showed that there are total 5 mono-rhamnolipid congeners with different nuclear mass ratio and relative abundance. This study laid foundation for heterologous biosynthesis of rhanomilipd.
Bacterial Proteins ; genetics ; Batch Cell Culture Techniques ; Decanoates ; Escherichia coli ; metabolism ; Fermentation ; Glycolipids ; biosynthesis ; Hexosyltransferases ; genetics ; Industrial Microbiology ; methods ; Multigene Family ; Promoter Regions, Genetic ; Pseudomonas aeruginosa ; Rhamnose ; analogs & derivatives ; biosynthesis ; Surface-Active Agents ; metabolism

Recently, the droplet microfluidic system attracts interests due to its high throughput and low cost to detect and screen. The picoliter micro-droplets from droplet microfluidics are uniform with respect to the size and shape, and could be used as monodispensed micro-reactors for encapsulation and detection of single cell or its metabolites. Therefore, it is indispensable to characterize micro-droplet and its application from droplet microfluidic system. We first constructed the custom-designed droplet microfluidic system for generating micro-droplets, and then used the micro-droplets to encapsulate important amino acids such as glutamic acid, phenylalanine, tryptophan or tyrosine to test the droplets' properties, including the stability, diffusivity and bio-compatibility for investigating its application for amino acid detection and sorting. The custom-designed droplet microfluidic system could generate the uniformed micro-droplets with a controllable size between 20 to 50 microm. The micro-droplets could be stable for more than 20 h without cross-contamination or fusion each other. The throughput of detection and sorting of the system is about 600 micro-droplets per minute. This study provides a high-throughput platform for the analysis and screening of amino acid-producing microorganisms.
Amino Acids ; isolation & purification ; Microfluidic Analytical Techniques ; Microfluidics ; instrumentation

Dabigatran etexilate mesylate(DE)and tadalafil(TD)are BCS class II drugs with poor water solubility. 〓 In this study coamorphization technique was used to improve their solubilities/dissolutions and hence to enhance their oral absorptions. The coamorphous DE-TD were prepared by solvent-evaporation method and characterized by PXRD, DSC, FTIR and TGA. In addition, dissolution behavior and physical stability were also investigated. Only halo pattern and a single Tg of 119 °C was observed on the PXRD and DSC of the co-evaporated product, respectively, indicating the formation of coamorphous DE-TD. FTIR result suggested that a hydrogen bond was probably formed between N-H group of DE and C==O group of TD. In comparison to crystalline counterparts, coamorphous DE-TD showed a significantly improved intrinsic dissolution rate and prolonged supersaturation time in intrinsic dissolution and supersaturation dissolution studies, respectively. No crystallization was observed under affecting factors testing(30 days)as well as long-term and accelerated stability testing(90 days)for the prepared coamorphous DE-TD under 25°C/60%RH or 40°C/75%RH, while amorphous DE crystalized at 10 days under 25 ℃/75% RH.

Because the work of administrative and logistics personnel in public hospitals is difficult to quantify and evaluate, its performance reform is difficult. A large public hospital in Wuhan has explored and established a distribution incentive mechanism that combines department performance appraisal, individual classification and grading, and secondary distribution within the department. Taking into account the completion of performance appraisal indicators of the national tertiary public hospital in the department, the results of the institutional " Excellent Management Team Ranking" , personal job grades, working years and other factors, a relatively mature and operable system has been formed, which could provide reference for the performance reform of other hospitals.

Objective:To investigate the pathological spectrum and variation of adult renal biopsies in People's Hospital of Xinjiang Uygur Autonomous Region from 1986 to 2020.Methods:The pathological data of 5 652 adult renal biopsies from August 1986 to December 2020 were retrospectively collected, and characteristics of pathological spectrum were analyzed. Regarding every 5 years as a research stage, the whole period was divided into 7 stages to analyze the pathological features and variation of renal biopsies. The first stage (P1) started from August 1986 to December 1990. The second stage (P2) started from January 1991 to December 1995. The third stage (P3) started from January 1996 to December 2000. The fourth stage (P4) started from January 2001 to December 2005. The fifth stage (P5) started from January 2006 to December 2010. The sixth stage (P6) started from January 2011 to December 2015. The seventh stage (P7) started from January 2016 to December 2020.Results:The age was (36.47±14.86) years old (18-83 years old) in 5 652 renal biopsies. There were 2 961 males (52.39%). There were 5 636 cases of autologous kidney biopsy and 16 cases of transplanted kidney biopsy. The descending order of incidence classified by disease types were primary glomerular disease (PGD, 4 470 cases, 79.31%), secondary glomerular disease (SGD, 994 cases, 17.64%), tubular-interstitial disease (160 cases, 2.84%), and hereditary nephropathy (12 cases, 0.21%). IgA nephropathy (IgAN, 1 573 cases, 35.19%) was the most frequent pathologic type of PGD, followed by membranous nephropathy (MN, 1 028 cases, 23.00%), mesangial proliferative glomerulonephritis (MsPGN, 878 cases, 19.64%), minimal change disease (MCD, 427 cases, 9.55%), and focal segmental glomerulosclerosis (345 cases, 7.72%). Lupus nephritis (LN, 251 cases, 25.25%) was the most common type of SGD, followed by hypertension nephropathy (193 cases, 19.42%), diabetic kidney disease (168 cases, 16.90%), purpura nephritis (138 cases, 13.88%), and ischemic nephropathy (90 cases, 9.05%). IgAN was the most common type of primary glomerulonephritis and mainly occurred in the age group of 18-59 years old. PGD was the most common glomerular disease in Han nationality (78.33%), Uygur nationality (81.72%) and other ethnic (77.15%) groups. Using Bonferroni correction method, the incidence of PGD in Uygur nationality was higher than that in Han nationality ( P<0.017). From P1 to P7, the detection rates of MN and MCD were increased in common renal pathological types, meanwhile, the ratio of MsPGN was decreased (all P<0.05). From P5 to P7, the detection rates of MN in Han nationality and Uygur nationality increased in the common pathological types of PGD, meanwhile, the ratio of MsPGN decreased (all P<0.05). LN was the most common SGD. The incidence of LN in females was higher than that in males ( P<0.001). Using Bonferroni correction method, the incidence of SGD in Uygur nationality was lower than that in Han nationality ( P<0.017). There was no significant variation in the common pathological type of SGD in Han and Uygur nationalities. Chronic rejection was the main pathological type of transplanted kidney biopsies. Conclusions:PGD is the main type of kidney disease spectrum in People's Hospital of Xinjiang Uygur Autonomous Region. IgAN is the most common PGD and mainly occurrs in the age group of 18-59 years old. As time goes by, the proportion of MN and MCD is increased, meanwhile the proportion of MsPGN is decreased significantly. LN is the most common SGD.

Objective:To investigate the risk factors for hemorrhagic transformation (HT) after intravenous thrombolysis (IVT) in patients with acute ischemic stroke (AIS), and the predictive value of Neutrophil to lymphocyte ratio (NLR).Methods:Consecutive patients with AIS received IVT in Zhengzhou People’s Hospital from January 2021 to December 2022 were retrospectively enrolled. HT was defined as no intracranial hemorrhage was found on the first imaging examination after admission, and new intracranial hemorrhage was found on the imaging examination 24 h after IVT or when symptoms worsened. sHT was defined as HT and the National Institutes of Health Stroke Scale (NIHSS) score increased by ≥4 compared to admission or required surgical treatment such as intubation and decompressive craniectomy. The baseline clinical and laboratory data of the patients were collected, and NLR, lymphocyte to monocyte ratio (LMR), and platelet to neutrophil ratio (PNR) were calculated. Multivariate logistic regression analysis was used to identify the independent predictors of HT and sHT, and receiver operating characteristic (ROC) curve was used to analyze the predictive value of NLR for HT and sHT after IVT. Results:A total of 196 patients were included (age 65.37±13.10 years, 124 males [63.3%]). The median baseline NIHSS score was 4 (interquartile range: 2-10). Twenty patients (10.2%) developed HT, and 12 (6.1%) developed sHT. Univariate analysis showed that there were statistically significant differences in age, baseline NIHSS score, creatinine, NLR, and stroke etiology type between the HT group and the non-HT group (all P<0.05); there were statistically significant differences in age, NLR, PNR, creatinine, baseline NIHSS score, and stroke etiological type between the sHT group and the non-sHT group (all P<0.05). Multivariate logistic regression analysis showed that NLR was an independent predictor of HT (odds ratio [ OR] 1.375, 95% confidence interval [ CI] 1.132-1.670; P=0.001) and sHT ( OR 1.647, 95% CI 1.177-2.304; P=0.004) after IVT. The ROC curve analysis showed that the area under the curve for predicting HT by NLR was 0.683 (95% CI 0.533-0.833; P=0.007), the optimal cutoff value was 5.78, the sensitivity and specificity were 55.0% and 84.1%, respectively. The area under the curve for predicting sHT by NLR was 0.784 (95% CI 0.720-0.839; P=0.001), the optimal cutoff value was 5.94, the sensitivity and specificity were 66.67% and 84.24%, respectively. Conclusions:A higher baseline NLR is associated with an increased risk of HT and sHT after IVT in patients with AIS, and can serve as a biomarker for predicting HT and sHT after IVT.

OBJECTIVETo explore the role of µ-opioid receptors (MOR) in the central nucleus of the amygdala (CeA) in modulating sucrose solution intake in rats.

METHODSSprague-Dawley rats received intra-CeA injection of MOR agonist DAMGO or saline, and then underwent two bottle choice test between sucrose solution and distilled water. After intake of sucrose solution or distilled water, activated neurons in the CeA were labeled and identified with MOR/Fos-double labeling immunohistochemistry.

RESULTSCompared with saline injection, intra-CeA injection of DAMGO significantly increased sucrose solution intake in rats over a 3-h period. Sucrose solution intake induced significantly more c-Fos and MOR/Fos double-labeled neurons in the CeA than distilled water intake.

CONCLUSIONSThe CeA participates in modulation of sucrose intake in rats, and MOR may partly mediate this mechanism.

Amygdala ; metabolism ; Animals ; Male ; Neurons ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Opioid, mu ; metabolism ; Sucrose ; metabolism

Objective To study the effect of deep inspiration breath-hold(DIBH)technique on the heart dose in whole breast irradiation(WBI)for left breast cancer after breast-conserving surgery, and to investigate the anatomical factors for heart dose. Methods Fifteen patients with left breast cancer who received WBI after breast-conserving surgery and met breathing control requirements were prospectively enrolled as subjects. Simulated CT scans were performed during free breathing(FB)and DIBH. The WBI plans were optimized based on DIBH images.The position,volume,and radiation doses to the heart and lung were compared between the status of FB and DIBH. Correlation of heart dose with various anatomical factors was analyzed in FB status. Between-group comparison of categorical data was made by nonparametric Wilcoxon rank test.A two-variable correlation analysis was made by the Pearson method.Results There was no significant difference in heart volume between the status of FB and DIBH(P=0.773).The volume of both lungs was significantly larger in DIBH status than in FB status(P=0.001). The mean and maximum doses and V5-V40for the heart,left anterior descending coronary artery,left ventricle,right ventricle,and left lung were significantly lower in DIBH status than in FB status(all P<0.05). The greater DIBH increased the lung volume,the greater the mean heart dose decreased. In FB status,the left breast volume,heart-to-lung volume ratio,distance between the inferior margins of breast and heart,and maximum heart margin distance showed a linear correlation with heart dose. Particularly, the heart-to-lung volume ratio and maximum heart margin distance were independently correlated with heart dose. Conclusions DIBH technique in WBI for left breast cancer after breast-conserving surgery significantly reduces heart and lung doses compared with FB. Changes in lung volume are the basis for improving the relative anatomical location of the heart. The heart-to-lung volume ratio and maximum heart margin distance may provide a reference for DIBH technique.