De novo synthesis of nervonic acid and optimization of metabolic regulation by Yarrowia lipolytica.

Nervonic acid, a natural fatty acid compound and also a core component of nerve fibers and nerve cells, has been widely used to prevent and treat related diseases of the brain nervous system. At present, fatty acids and their derivatives are mainly obtained by natural extraction or chemical synthesis which are limited by natural resources and production costs. In this study, the de novo synthetic pathway of nervonic acid was constructed in Yarrowia lipolytica by means of synthetic biology, and the yield of nervonic acid was further improved by metabolic engineering and fermentation optimization. Specially, heterologous elongases and desaturases derived from different organism were successfully expressed and evaluated for their potential for the production of nervonic acid in Y. lipolytica. Meanwhile, we overexpressed the genes involved in the lipid metabolism to increase the nervonic acid titer to 111.6 mg/L. In addition, the potential of adding oil as auxiliary carbon sources for nervonic acid production by the engineered Y. lipolytica was analyzed. The results indicated that supplementation with colleseed oil as an auxiliary carbon source can be beneficial for the nervonic acid productivity, which led to the highest concentration of 185.0 mg/L in this work. To summarize, this study describes that the Y. lipolytica can be used as a promising platform for the production of nervonic acid and other very long-chain fatty acids.

Iterative gene integration mediated by 26S rDNA and non-homologous end joining for the efficient production of lycopene in Yarrowia lipolytica.

Because of its potent antioxidant effects, lycopene has been used in various industries including, but not limited to, food, medical, and cosmetic industries. Yarrowia lipolytica, a non-conventional yeast species, is a promising chassis due to its natural mevalonate (MVA) pathway, abundant precursor acetyl coenzyme A content, and oleaginous properties. Several gene editing tools have been developed for Y. lipolytica along with engineering strategies for tetraterpenoid production. In this study, we engineered Y. lipolytica following multi-level strategies for efficient lycopene accumulation. We first evaluated the performance of the key lycopene biosynthetic genes crtE, crtB, and crtI, expressed via ribosomal DNA (rDNA) mediated multicopy random integration in the HMG1- and GGS1-overexpressing background strain. Further improvement in lycopene production was achieved by overexpressing the key genes for MVA synthesis via non-homologous end joining (NHEJ) mediated multi-round iterative transformation. Efficient strategies in the MVA and lipid synthesis pathways were combined to improve lycopene production with a yield of 430.5 mg/L. This strain produced 121 mg/g dry cell weight of lycopene in a 5-L fed-batch fermentation system. Our findings demonstrated iterative gene integration mediated by 26S rDNA and NHEJ for the efficient production of lycopene in Y. lipolytica. These strategies can be applied to induce Y. lipolytica to produce other tetraterpenoids.

Early results of coronary endarterectomy combined with coronary artery bypass grafting in patients with diffused coronary artery disease.

BACKGROUND: It is still a challenge for the cardiac surgeons to achieve adequate revascularization for diffused coronary artery disease (CAD). Coronary endarterectomy (CE) offers an alternative choice of coronary artery reconstruction and revascularization. In this study, short-term result of CE combined with coronary artery bypass graft (CABG) was discussed in the treatment for the diffused CAD. METHODS: From January 2012 to April 2014, 221 cases of CABG were performed by the same surgeon in our unit. Among these cases, 38 cases of CE + CABG were performed, which was about 17.2% (38/221) of the cohort. All these patients were divided into two groups: CE + CABG group (Group A) and CABG alone group (Group B). All clinical data were compared between the two groups, and postoperative complications and in-hospital mortality were analyzed. The categorical and continuous variables were analyzed by Chi-square test and Student's t-test respectively. RESULTS: Diabetes mellitus, hypertension, hyperlipidemia, and peripheral vascular disease were more common in group A. In this cohort, a total of 50 vessels were endarterectomized. Among them, CE was performed on left anterior descending artery in 11 cases, on right coronary artery in 29 cases, on diagonal artery in 3 cases, on intermediate artery in 2 cases, on obtuse marginal artery in 5 cases. There was no hospital mortality in both groups. The intro-aortic balloon pump was required in 3 cases in Group A (3/38), which was more often than that in Group B (3/183). At the time of follow-up, coronary computed tomography angiogram showed all the grafts with CE were patent (50/50). There is no cardio-related mortality in both groups. All these patients were free from coronary re-intervention. CONCLUSIONS: Coronary endarterectomy + CABG can offer satisfactory result for patients with diffused CAD in a short-term after the operation.

Trade-offs of the opto-electrical properties of a-Si:H solar cells based on MOCVD BZO films.

Boron-doped zinc oxide (BZO) films, deposited by metal-organic chemical vapor deposition (MOCVD), have been widely used as front electrodes in thin-film solar cells due to their native pyramidal surface structure, which results in efficient light trapping. This light trapping effect can enhance the short-circuit current density (Jsc) of solar cells. However, nanocracks or voids in the silicon active layer may form when the surface morphology of the BZO is too sharp; this usually leads to degraded electrical properties of the cells, such as open-circuit voltage (Voc) and the fill factor (FF), which in turn decreases efficiency (Eff) [Bailat et al., Photovoltaic Energy Conversion, Conference Record of the 2006 IEEE 4th World Conference on. IEEE, 2006, vol. 2, pp. 1533-1536]. In this paper, an etching and coating method was proposed to modify the sharp "pyramids" on the surface of the BZO films. As a result, an evident enhancement was achieved for these modified, BZO-based cells' Voc, FF, and Eff, although the Jsc exhibited a small decrease. In order to increase the Jsc and maintain the improved electrical properties (Voc, FF) of the cell, a thin BZO coating, deposited by MOCVD, was introduced to coat the sputtering-treated BZO film. Finally, we optimized the trade-off among the Voc, FF, and Jsc, that is, we identified a regime with an increase of the Jsc as well as a further improvement of the other electrical properties.

[Safety analysis of application of medical anti-adhesion modified chitosan in cardiac surgery].

OBJECTIVE: To verify the application safety of medical anti-adhesion modified chitosan (Baifeimi) in cardiac surgery. METHODS: From August to December 2010, 42 patients undergoing surgery for congenital heart disease, valvular heart disease or ischemic heart disease were selected and divided into testing (n = 22) and control (n = 20) groups. After complete intraoperative hemostasis, two sheets of anti-adhesion modified chitosan (Baifeimi) were placed on the surface of heart and vessels in the testing group and then chest was closed. And the control group underwent routine chest closing without an application of Baifeimi. The systemic and local reactions and drainage fluid were observed. The postoperative drainage fluid was subject to bacteria culture. Blood routines and laboratory tests at preoperation and Day 1 and Week 1 postoperation were performed to evaluate the changes of chemical, biological and immunological parameters. RESULTS: There was no occurrence of systemic reaction, local inflammation or exudation.Wounds were healed at Phase I. The drainage fluid of pericardium and mediastina had no significant intergroup difference. Drainage was unobstructed in the testing group. A comparison of two groups revealed that the differences of aspartate aminotransferase ( (24 ± 17) vs (40 ± 22) U/L), preoperative and postoperative immunoglobulin A( (1.9 ± 0.7) vs (2.9 ± 1.4) g/L, (2.3 ± 0.9) vs (3.3 ± 1.5) g/L) were statistically significant (all P < 0.05). But the average values of both group stayed within a normal range without clinical significance while other indices had no significant difference. The bacteria cultures of all patients in the control group were negative. CONCLUSIONS: Anti-adhesion modified chitosan is both convenient and safe for clinical application. The duration of cardiac surgery is not extended.No systemic or local adverse event is reported. There is no interference of hepatic, renal or immune functions.

Silencing of Cathepsin B suppresses the proliferation and invasion of endometrial cancer.

The molecular mechanism involved in the metastasis of endometrial cancer (EC) remains unclear. The lysosomal cysteine protease Cathepsin B has been implicated in the progression of various human tumors. In the present study, we assessed the expression of Cathepsin B and its functions in EC. Immunohistochemistry was used to examine Cathepsin B expression in 76 paraffin-embedded endometrial tumor tissues. Lentiviral packing short hairpin RNA (shRNA) was transfected into HEC-1A cells to build a stable Cathepsin B knockdown cell line. The cellular levels of Cathepsin B mRNA and protein were detected by real-time PCR and western immunoblotting. The functions of Cathepsin B in EC cells were measured by MTT, migration and invasion assays. In additon, tumorigenicity assays were established in nude mice to study tumor growth in vivo. The results of our study showed that Cathepsin B was overexpressed in EC tissues compared with normal endometrium and endometrial atypical hyperplasia. Depletion of Cathepsin B in vitro inhibited cell proliferation, migration and invasion. Tumor formation assays confirmed that suppression of Cathepsin B inhibited the proliferation potential of HEC-1A cells in vivo, demonstrated by lower proliferation rates. These results suggest that Cathepsin B may act as an oncogene in EC, with the potential to provide a new therapeutic target for treating endometrial malignancy.

The comparison of an inexpensive-modified transobturator vaginal tape versus TVT-O procedure for the surgical treatment of female stress urinary incontinence.

OBJECTIVE: To compare the safety and efficacy of an inexpensive-modified transobturator vaginal tape procedure with the transobturator tension-free vaginal tape (TVT-O) procedure for the surgical treatment of female stress urinary incontinence (SUI). MATERIALS AND METHODS: Patients with SUI were randomly allocated to either the test group receiving the inexpensive-modified transobturator vaginal tape procedure or the control group receiving the GYNECARE TVT-O procedure. Treatment outcomes and Quality-of-life scores were recorded and analyzed between two groups. RESULTS: A total of 156 patients were enrolled in this trial. Eighty patients underwent the modified transobturator vaginal tape procedure. Among them 75(93.8%) were cured and 5(6.2%) were improved. The rest of the 76 patients underwent the GYNECARE TVT-O procedure with a 92% (70 of 76) cure rate and an 8% (6 of 76) improvement rate. No inefficient or aggravated cases occurred in both groups. The success rates between groups had no significant statistic difference (p > 0.05). The operative time, blood loss, hospital stay, and medical cost were significantly lower in the test group (p < 0.01); the increases in Quality-of-life scores were comparable between groups. CONCLUSIONS: The modified transobturator vaginal tape procedure is an efficacious and economic surgical treatment for female SUI.

Atom-economical chemoselective synthesis of 1,4-diynes and polysubstituted furans/pyrroles from propargyl alcohols and terminal alkynes.

Under different conditions, the reaction of propargyl alcohols and terminal alkynes leads to the selective formation of 1,4-diynes and polysubstituted furans/pyrroles. Water is the only byproduct in the selective synthesis of 1,4-diynes and pyrroles, and the strategy for the furan synthesis is of 100% atom economy.

[Study on discrimination of varieties of corn using near-infrared spectroscopy based on GA and LDA].

A new method for the fast discrimination of varieties of corn based on near-infrared spectroscopy using genetic algorithm and linear discriminant analysis (LDA) was proposed. First, data of NIS of 37 varieties of corn was collected, second, genetic algorithm used for choosing the feature band of spectrum, then PCA and LDA were used to extract features, and finally corn seeds were classified. The result showed that GA could remove noise band effectively and improve the generalization ability of LDA. A large number of redundant data was removed to simplify the computing, which resulted in the data dimension reduction from 2075 to 233. For the 300 samples of test set one, the average correct recognition rate and average correct rejection rate attained 99.30% for both, and the average correct recognition rate of 73.33% varieties of corn attained for 100%. For the 175 samples of test set 2 (all of whose varieties had not been trained), the average correct recognition rate attained 99.65%. The run time is shorter and the correct rate is higher compared to the common method of PCA.

[A frequency selection method of NIR spectroscopy for discrimination of maize seed varieties].

A frequency selection method of NIR spectroscopy was proposed in the present paper for discrimination of maize seed varieties. A criterion function was defined to evaluate the discriminative ability of NIR spectroscopy at different frequencies, and then features of maize seed varieties were extracted accordingly for further processing. By eliminating correlation between features at different frequencies, the selected features are guaranteed to contain as much information of inter-variety difference as possible. Also, features with larger variances are preferred to suppress the impact of noise. Experiment results demonstrate that our frequency selection method can achieve high recognition rate with less spectroscopy features than traditional methods. Specifically, a recognition rate as high as 94.16% can be attained with NIR spectroscopy with only 30 frequencies. Simulation results show that recognition rate of NIR spectroscopy at selected frequencies is stable with small disturbance of frequencies, which verifies the robustness of the authors' method.

[Feature analysis and discrimination of varieties of corn based on near infrared spectra].

A new method for the discrimination of varieties of corn was proposed based on the data set of near-infrared spectroscopy range from 4 000 to 12 000 cm(-1) of corn seed varieties. Principal component analysis (PCA) method was used to study the feature of the data, and the authors found that the near-infrared spectroscopy of corn seed varieties has a clear feature of zonal distribution, so the correlativity between the change in the distribution of the principal component and the discrimination result was studied, according to which the normalized principal component analysis (NPCA) method was proposed. Besides, principal direction biomimetic pattern recognition (PBPR) was proposed according to the feature, which got a better discrimination result. The average correct recognition rate attained 97.67% for test set I, and the average correct rejection rate attained 98.40%, with 13 of the 30 varieties reaching the correct recognition rate of 100%; The average correct rejection rate attained 98.90% for the test set II , and 11 of the 30 varieties reached the correct rejection rate of 100%. It was proved that the method had a high correct discrimination rate.

[Clinical research of a butterfly shaped mesh in the treatment of stress urinary incontinence].

OBJECTIVE: To investigate the effect of a butterfly shaped mesh in treatment of stress urinary incontinence (SUI). METHODS: From July 2003 to January 2004, 82 patients with SUI were treated with a butterfly shaped mesh. All patients were followed up at 1st, 3rd, 6th month after operation. According to their complaints, the cure standard of urinary incontinence is that the patient can control micturate by herself. The improved is that the times and volume of urinary incontinence is less than before. The inefficacy is that the patients' symptoms is not improved even more than before. RESULTS: All patients were operated under local anesthesia. Mean operation time was (27 +/- 9) min, and mean blood loss was (21 +/- 6) ml. Seventy two patients were able to micturate spontaneously at 2nd hour after operation and the volume of residual urine was less than 100 ml after 24 hour behind operation. They were discharged on the next day. 10 patients, an in-dwelling catheter had been used for 48 hours because the volume of residual urine was more than 100 ml. Seventy eight of 82 patients had no signs of stress incontinence. The remaining 4 patients with apoplexy history showed leakage of urine slightly. But their signs were improved obviously after a month. Seventy six patients had been followed up for from 1 to 6 month: 74 patients were completely cured, and the other 2 patients were improved. No urine retention, infection or bladder dysfunction were observed. CONCLUSION: A butterfly shaped mesh is effective, simple and safe procedure to treat stress urinary incontinence.

[Repair of femoral neck fracture with vascular pedicled periosteum flap transfer in young and middle-aged].

OBJECTIVE: To estimate clinical effect of spin iliac deep vascular pedicled periosteum flap in repairing traumatic femoral neck of theca inside fracture in young and middle-aged. METHODS: From April 1993 to September 2001, 12 cases of traumatic femoral neck fracture were given diaplastic operation with fixation of 3 centre hollow pressed bolt and were conducted under os traction bed and "C" arm X-ray machine. Spin iliac deep vascular pedicled periosteum flap was stripped off, and transferred to the front of femoral neck fundus, then transplanted to the narrow inside of fracture through outer open door of articular capsule. RESULTS: All patients were followed up for 1-7 years. All fracture healed without femoral head necrosis, but mild arthritis appeared in 7 cases. CONCLUSION: Vascular pedicled periosteum flap transfer of young and middle-aged femoral neck fracture, by decompression of femoral neck and reconstruction of blood circulation, can promote the fracture healing and decrease the wound and blood circulation destroy.