Cyanobacteria are the only prokaryotes capable of oxygenic photosynthesis, which have potential to serve as "autotrophic cell factories". However, the synthesis of biofuels and chemicals using cyanobacteria as chassis are suffered from poor stress tolerance and low yield, resulting in low economic feasibility for industrial production. Thus, it's urgent to construct new cyanobacterial chassis by means of synthetic biology. In recent years, adaptive laboratory evolution (ALE) has made great achievements in chassis engineering, including optimizing growth rate, increasing tolerance, enhancing substrate utilization and increasing product yield. ALE has also made some progress in improving the tolerance of cyanobacteria to high light intensity, heavy metal ions, high concentrations of salt and organic solvents. However, the engineering efficiency of ALE strategy in cyanobacteria is generally low, and the molecular mechanisms underpinning the tolerance to various stresses have not been fully elucidated. To this end, this review summarizes the ALE-associated technical strategies and their applications in cyanobacteria chassis engineering, following by discussing how to construct larger ALE mutation library, increase mutation frequency of strains and shorten evolution time. Moreover, exploration of the construction principles and strategies for constructing multi-stress tolerant cyanobacteria, and efficient analysis the mutant libraries of evolved strains as well as construction of strains with high yield and strong robustness are discussed, with the aim to facilitate the engineering of cyanobacteria chassis and the application of engineered cyanobacteria in the future.
Technology ; Photosynthesis/genetics* ; Cyanobacteria/genetics* ; Light ; Biofuels

Objective To establish a noninvasive diagnostic model for chronic hepatitis B (CHB) liver fibrosis based on LASSO regression using serological parameters, and to investigate the value of this model in the diagnosis of CHB liver fibrosis. Methods A total of 240 patients who were diagnosed with CHB in Changzhou Second People's Hospital, Nanjing Medical University, from September 2019 to September 2021 were enrolled as subjects, and according to the results of liver biopsy and pathology, they were divided into significant liver fibrosis (stage F2-F4) group with 175 patients and non-significant liver fibrosis (stage F0-F1) group with 65 patients. The two groups were compared in terms of sex, age, blood biochemical parameters, and liver stiffness measurement (LSM) measured by two-dimensional shear wave elastography, and LASSO regression and the multivariate logistic regression analysis were used screen out the risk factors for liver fibrosis. A nomogram model was established and then verified by the receiver operating characteristic (ROC) curve, calibration curve, and decision curve. A one-way analysis of variance was used for comparison of normally distributed continuous data between multiple groups, and the least significant difference t -test was used for further comparison between two groups; the Kruskal-Wallis H test was used for comparison of non-normally distributed continuous data between groups; the chi-square test was used for comparison of categorical data between groups. Results There were significant differences between the patients with stage F3/F4 liver fibrosis and those with stage F2/F0-F1 liver fibrosis in age, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyl transpeptidase, total bilirubin, platelet count, procollagen type Ⅲ, type Ⅳ collagen, hyaluronic acid, and LSM (all P < 0.05). Five important variables were screened out by LASSO regression, and the logistic regression analysis showed that hyaluronic acid (odds ratio [ OR ]=1.432, P < 0.05), type Ⅳ collagen ( OR =1.243, P < 0.05), procollagen type Ⅲ( OR =1.146, P < 0.05), and LSM ( OR =1.656, P < 0.05) were the independent risk factors for liver fibrosis, while platelet count ( OR =0.567, P < 0.05) was a protective factor. Compared with the patients with stage F2/F0-F1 liver fibrosis, the patients with stage F3/F4 liver fibrosis had significantly higher score of the nomogram model, LSM, aspartate aminotransferase-to-platelet ratio index (APRI), King score, Forns index, and fibrosis-4 (FIB-4) index (all P < 0.05). The ROC curve was used to analyze the predictive value of the nomogram model, and the results showed an area under the ROC curve of 0.876, which was significantly higher than that of LSM, APRI, King score, Forns index, and FIB-4 (all P < 0.05). Calibration curve and decision curve showed that the nomogram model had acceptable consistency and benefit. Conclusion The noninvasive nomogram model based on LASSO regression is established by using serum parameters including hyaluronic acid, type Ⅳ collagen, procollagen type Ⅲ, platelet count, and LSM, and as a quantitative tool for the clinical diagnosis of CHB liver fibrosis, it has a high diagnostic efficiency and thus holds promise for clinical application.

As human life expectancy continues to increase and the birth rate continues to decline, the phenomenon of aging is becoming more prominent worldwide. Therefore, addressing the problems associated with global aging has become a current research focus. The main manifestations of human aging are structural degeneration and functional decline of aging tissues and organs, quality of life decline, decreased ability to resist diseases, and high incidence rates of a variety of senile degenerative diseases. Thus far, no ideal treatments have been found. Stem cell (SC) therapies have broad application prospects in the field of regenerative medicine due to the inherent biological characteristics of SCs, such as their plasticity, self-renewal, and multidirectional differentiation potential. Thus, SCs could delay or even reverse aging. This manuscript reviews the causes of human aging, the biological characteristics of SCs, and research progress on age reversal.

Objective:To describe the treatment of the first carpometacarpal arthritis in Eaton Ⅱ, Ⅲ combining the hemi excision of trapezium with tendon ball and evaluate its clinical efficacy.Methods:Data of patients with the first carpometacarpal arthritis who were treated by hemi excision of trapezium and tamponade of the tendon ball from March 2013 to October 2018 were retrospectively analyzed. Twelve patients were all females with an average age of 55±2.8 years (range, 48-61 years). There were 3 cases of left thumbs and 9 cases of right. The study was only researched with primary osteoarthritis patients, preoperative imaging Eaton stages, including 8 cases inⅡstage, 4 cases in Ⅲ stage. Postoperative X-ray examination was performed, and the subsidence rate of the first metacarpal bone was evaluated according to height of arthroplasty. Preoperative and postoperative pain was evaluated according to visual analogue scales (VAS) score and DASH score. Preoperative and postoperative finger movement was evaluated according to the changes in preoperative and postoperative grip and pinch force.Results:The average follow-up period was 12±4.8 months (range, 6-17 months). The mean score of VAS after operation was 1.2±1.0 which was lower than 6.3±1.5 before operation ( t=13.4, P=0.0001); DASH score after operation was 26.2±9.6 which was lower than 48.9±13.0 before operation ( t=5.7, P=0.0001); Grip force after operation was 25.5±6.8 kg which was higher than 15.0±2.9 kg before operation ( t=7.3, P=0.0001); Pinch force after operation was 3.2±0.8 kg which was higher than 2.1±0.4 kg before operation ( t=3.6, P=0.0045), and all of these four above data has statistic difference. At the latest postoperative follow-up, the height index of arthroplasty was 0.299±0.022, and there was no significant change ( F=1.337, P=0.276) when compared with 0.306±0.021 before surgery and 0.313±0.024 after surgery. After the operation, 2 patients presented with incision redness and swelling and exudation. It was considered that local hematoma in the intra-articular operation could not be completely absorbed. After several dressing changes, the redness and swelling subsided and the exudation was controlled. Conclusion:Preserving the proximal joint surface of trapezium and tamponading tendon ball, could reduce the subsidence rate of the first metacarpal bone and alleviate the pain of the first carpometacarpal joint, thus may effectively improve the joint function. It has a significant effect on the treatment of Eaton Ⅱ,Ⅲ stage of the first carpometacarpal arthritis.

Objective To investigate the cluster nursing in improving the weaning success rate of emergency neurally adjusted ventilatory assist (NAVA) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).Methods A total of 72 AECOPD patients treated with NAVA in the Second Affiliated Hospital of Wenzhou Medical University emergency intensive care unit (EICU) from January 2014 to January 2016 were collected and randomly divided into observation group and control group according to the random number table, 36 cases respectively. The observation group received the cluster nursing, and the control group used the traditional nursing. The incidence of ventilator associated pneumonia (VAP), length of stay, the service time and weaning success rate of ventilator were compared between two groups.Results The length of stay in EICU [(7.33±1.79) d]and the service time of ventilator [(3.17±0.63) d]in the observation group were shorter than those in the control group, the differences were statistically significant (t=8.912, 16.524;P<0.05). The incidence of VAP (13.89%) in the observation group was statistically significantly lower than those in the control group (χ2=9.425,P<0.05). The weaning success rate (86.11%) in the observation group was significantly higher than that in the control group (χ2=8.134,P<0.05).Conclusions The cluster nursing in AECOPD patients with emergency NAVA treatment can significantly reduce the ventilator-associated complications and improve the success rate of weaning. It is worthy of clinical promotion.

Objective To investigate the metabolism characteristics and the potetial biomarker candidates of osteonecro?sis of the femoral head (ONFH) using metabolomic technology. Methods The femoral head specimens from 23 ONFH patients (25 necrotic femoral heads) and 18 normal femoral heads from femoral neck fracture patients were collected for histopathological examination to confirm the diagnosis of all samples. All the metabolites of bone trabecula were extracted for ultra-high perfor?mance liquid chromatography-MS/MS analyzed. The measured variables was pretreat, and PCA (principal component analysis), PLS?DA (partial least squares?discriminant analysis) and OPLS?DA (orthogonal?partial least squares?discriminant analysis) models were employed to confirm the difference between these two groups after UPLC?MS/MS (ultra?high performance liquid chromatogra?phy?mass spectrometry/mass spectrometry) analysis. At last, the differential variables were screened out by PLS?DA and variate analysis (Kruskal?Wallis H test). The changed metabolites were confirmed by MS and MS/MS aligned in HMDB (human metabolo?mic database) and Massbank. The changed metabolites with the most obviously changed peak abundance, D?arginine, L?proline and L?glutamine, were picked out as the potential diagnostic biomarkers. After binary logistic regression analysis, the combined biomarkers candidates were further analyzed by receiver operating characteristic (ROC) curve to evaluate the significance of the combined biomarkers. Results Significant distinction of metabolites expression mode can be seen in PCA, PLS?DA and OPLS?DA models scoring plots between ONFH and control groups. Twelve changed metabolites in ONFH bone trabeculas were con?firmed by multi?variate statistical analysis and variate statistical analysis. Compared with the femoral neck fracture patients, the in?creased metabolites included D?arginine, L?proline, L?glutamine, creatine, uracil, uridine, LysoPC(20∶4(5Z, 8Z, 11Z, 14Z)), Ly?soPC(16∶0), PC(20∶1(11Z)/18∶3(6Z, 9Z, 12Z)) and PE(P?16∶0e/0∶0). The decreased metabolites were reticulataxanthin and β?cryptoxanthin. According to the change fold of peak abundance and variable weight projection in PLS?DA, the most obviously dif? ferential metabolites were picked out as the biomarker candidates of ONFH. The potential biomarkers candidates were identified as D?arginine, L?proline and L?glutamine. The area under the curve of D?arginine, L?proline and L?glutamine ROC were 0.873, 0.712 and 0.862. The area under the curve of ROC was 0.946 after combining D?arginine, L?proline, L?glutamine using binary lo?gistic regression analysis. Conclusion PCA, PLS?DA and OPLS?DA models were used to find out the differential variables in the metabolites of bone trabeculas in ONFH and femoral neck fracture patients. Twelve metabolites were identified by MS/MS, and 3 obviously changed metabolites, D?arginine, L?proline, L?glutamine, were indicated as biomarker candidates. These 3 obviously changed metabolites showed a good diagnostic significance.

BACKGROUND:A variety of cel lines participate in the construction of animal models of osteosarcoma. OBJECTIVE:To compare the abilities of subcutaneous tumorigenesis of human osteosarcoma cel lines MG63, U2OS and 143B in nude mice, and to establish the basis for experimental studies on osteosarcoma. METHODS:A total of 18 nude mice were randomly divided into MG63, U2OS and 143B groups. The back of nude mice was subcutaneously injected with MG63, U2OS and 143B cel lines in corresponding groups, and the process of tumorigenesis was observed. RESULTS AND CONCLUSION:MG63 and U2OS could not induce subcutaneous tumorigenesis in nude mice. Tumors were observed after injection with 143B cels for (6±1) days, with the tumor formation rate of 100% (6/6). The tumor grew very fast. The mean volume of tumors was (3 475±1 544) mm3 at 2 months. The survival time of nude mice burdened with tumors was (68±10) days. Hematoxylin-eosin staining revealed that in tumor tissue, cancer cels formed nest shape, nuclei were big and darkly stained, and split mostly. These results suggested that 143B cel line could wel induce subcutaneous tumorigenesis, which could be used for animal research of osteosarcoma.

Objective To study effect of high ilioinguinal approach in treatment of acetabular fractures involving quadrilateral plate. Methods 28 cases of acetabular fractures were randomly divided into two groups according to admission time. 16 patients in the observation group were given high ilioinguinal approach operation. 12 patients in the control group were treated with traditional ilioinguinal approach op-eration. Operation condition, fracture reduction, the hip function recovery and postoperative complications of the two groups were compared. Results The amount of bleeding, the length of incision, operation time and operation conditions of the two groups had no significant differ-ence (P>0. 05). The satisfactory fracture reduction rate of observation group was higher than the control group (P<0. 05). Hip function score of observation group was significantly higher than that of the control group (P<0. 05). In observation group, the excellent rate of hip joint function was better than that of the control group (P<0. 05). The incidence rate of complications in the observation group and the con-trol group were 12. 50% and 16. 67% respectively, and there was no significant difference between the two groups (P>0. 05). Conclusion High ilioinguinal approach can improve the fracture reduction effect, effectively improve the hip joint function in patients, and it has higher security which is a kind of ideal treatment approach for acetabular fractures involving quadrilateral plate.

OBJECTIVETo examine the oral health status among the orphan children and adolescents of Chongqing and assist in planning of the oral health programs.

METHODSAccording to the third national oral health investigation of epidemiology, the dental caries, gingival bleeding and calculus was examined among 317 orphan living in Chongqing, by cluster sampling. The statistical software SPSS 17.0 was used for the data analysis.

RESULTSIn primary and permanent teeth, the prevalence of dental caries and mean DMFT (dmft) were found to be 50.00%, 1.94 +/- 2.81 and 39.53%, 0.90 +/- 1.38. There were no significant difference between female and male (P>0.05). But there was significant difference of the prevalence of permanent tooth caries between the age group under 12 (include 12) and above 12 (P < 0.05). It was also found that 35.25% of the orphan children and adolescents had caries in the first permanent molar, and there was significant difference between female and male (P < 0.05). Neither of the caries teeth above was treated nor the healthy teeth were sealed. The prevalence rate of gingival bleeding was 78.22%, and the calculus rate was 67.66%.

CONCLUSIONThe oral status of the orphan is poor, and this community has experienced a low utilization of preventive or therapeutic oral health services. In the future work, orphans should be considered as a priority group when make plans for oral health care.

Adolescent ; Child ; Child, Preschool ; China ; DMF Index ; Dental Caries ; Dentition, Permanent ; Female ; Health Status ; Humans ; Male ; Molar ; Oral Health ; Prevalence

Objective To construct stable chromokinesin KIF4A knockdown gastric cancer cell lines (SGC-7901) and study the mitotic spindle midzone formation in these cells.Methods Short hairpin RNA (shRNA) expression plasmids of pGPU-GFP-shKIF4A,pGPU-GFP-shNC specific targetting KIF4A and non-sense DNA sequences were constructed respectively and then transfected into SGC-7901 cells.The cells were cultured in selection medium containing G418 to form single clones.Stable KIF4A shRNA expressing SGC-7901 cells were picked up under an fluoroscent microscope and identified by Western Blot.The spindle midzone in these cells was analyzed after immunofluorescence staining.Results Three cell lines stably expressing KIF4A shRNA and one with shNC were successfully constructed.Compare to the control cell line,KIF4A knockdown cell lines represented remarkable elongation of spindle midzone and the less the KIF4A,the longer spindle midzone.Conclusions Stable KIF4A knockdown SGC-7901 cell lines were successfully constructed that can serve for further study of KIF4A ' s function and its role in proliferation and development of gastric cancer.