[Cadmium Phytoremediation Effect of Sweet Sorghum Assisted with Citric Acid on Typical Parent Soil in Southern China].

Sweet sorghum has a large biomass and strong cadmium (Cd) absorption capacity, which has the potential for phytoremediation of Cd-contaminated soil. In order to study the Cd phytoremediation effect of sweet sorghum assisted with citric acid on the typical parent materials in southern China, a field experiment was carried out in two typical parent material farmland areas (neutral purple mud field and jute sand mud field) with Cd pollution in Hunan Province. The results showed that:① Citric acid had no inhibitory effect on the growth of sweet sorghum. After the application of citric acid, the aboveground biomass of sweet sorghum at the maturity stage increased by 10.1%-24.7%. ② Both sweet sorghum planting and citric acid application reduced the soil pH value, and the application of citric acid further reduced the soil pH value at each growth stage of sweet sorghum; this decrease was greater in the neutral purple mud field, which decreased by 0.24-0.72 units. ③ Both sweet sorghum planting and citric acid application reduced the total amount of soil Cd, and the decreases in the neutral purple mud field and jute sand mud field were 23.8%-52.2% and 17.1%-31.8%, respectively. The acid-extractable percentage of soil Cd in both places increased by 38.6%-147.7% and 4.8%-22.7%, respectively. ④ The application of citric acid could significantly increase the Cd content in various tissues of sweet sorghum. The Cd content in the aboveground part of the plant in the neutral purple mud field was higher than that in the jute sand mud field, and the Cd content in stems and leaves was 0.25-1.90 mg·kg-1 and 0.21-0.64 mg·kg-1, respectively. ⑤ After applying citric acid, the Cd extraction amount of sweet sorghum in neutral purple mud soil in the mature stage reached 47.56 g·hm-2. In summary, citric acid could enhance the efficiency of sweet sorghum in the phytoremediation of Cd-contaminated soil, and the effect was better in neutral purple mud fields. This technology has the potential for remediation coupled with agro-production for heavy metal-contaminated farmland.

[Effect of Silica Fertilizer(Husk Ash) to Improve Soil Quality and Reduce Cd and As Accumulation in Rice].

A rice pot experiment was conducted to identify the effect of silica fertilizer prepared from husk ash on the soil bioavailability of cadmium (Cd) and arsenic (As), enzyme activities, microbial community structure, and heavy metal content in brown rice at different growth stages. The results showed that the application of 0.1%-1.0% silica fertilizer-husk ash increased the pH value of soil by 0.04-0.24 units and the content of soil available silicon by 44.2%-97.5%. It also decreased the content of available Cd and available As by 16.2%-21.4% and 16.0%-24.9%, respectively. With the increase in application amount, the soil enzyme activities increased at all growth stages, and the sucrase activity and the dehydrogenase activity significantly increased by 6.3%-145.7% and 6.7%-224.1%, respectively. The analysis of the soil microbial community composition structure at mature stages showed that the application of silica fertilizer-husk ash had no effect on microbial α-diversity, but it had a significant effect on microbial ß-diversity and then promoted microbial growth and maintained the stability of the community structure. With the increase in application amount, the contents of Cd in brown rice decreased by 29.3%-89.7%, and the contents of total As and inorganic As in brown rice decreased by 7.8%-42.3% and 17.2%-44.5%, respectively. Under the application of 0.5% and 1.0% silica fertilizer-husk ash, the Cd contents in brown rice were lower than 0.2 mg·kg-1, and the inorganic As contents in brown rice were lower than 0.35 mg·kg-1. In conclusion, the silica fertilizer-husk ash can improve soil quality and reduce the contents of Cd and As in brown rice, and it is eco-friendly and can be used to remedy the paddy soil contaminated with Cd and As.

Porous Core-membrane Microstructured Nanomaterial Composed of Deep Eutectic Solvents and MOF-808 for CO2 Capture.

A series of porous core-membrane microstructured nanomaterials, constructed of a deep eutectic solvent (DES) membrane and porous MOF-808 core via liquid surface tensions and electrostatic interactions, are introduced for carbon dioxide capture with the sorption mechanism coupling diffusion, physisorption, and chemisorption. MOF-808 as the porous core considerably improves the diffusion interactions for DES membranes, hence significantly enhancing the sorption performance of DESs. Although the DES consisted by monoethanolamine and tetrapropylammonium chloride (MEA-TPAC-7) has the highest sorption capacity among all DESs, it is only 4.39 mmol g-1 at 2.4 bar and further attenuates by fastidious diffusion interactions when increasing viscosity or dose. The sorption capacities of DES@MOF-120 are 5.18 mmol g-1 at 3.0 bar and 4.78 mmol g-1 at 2.4 bar without apparent sorption hysteresis in pressure swing sorption, which are substantially improved contrasted to MEA-TPAC-7. The sorption isotherms are reconstructed via Sips models considering surface heterogeneity with regression correlation coefficients over 0.9454 to forecast maximum sorption capacity over 6.33 mmol g-1 .

Coagulation Factors for Diagnosis of Periprosthetic Joint Infection / 中山大学学报(医学科学版)

ObjectivePeriprosthetic joint infections （PJI） are currently the most calamitous complication after arthroplasty. Although achievements have been made in many markers for the diagnosis of PJI， the lack of a gold standard remains a great obstacle for early diagnosis. This study aimed to investigate the association between coagulation markers and the development of PJI in patients undergoing revision total joint arthroplasty （TJA）. MethodsWe conducted a retrospective cohort study with a total of 2 517 patients who underwent hip or knee arthroplasties from January 2011 to January 2022 （2 394 with primary TJA， 87 with aseptic revision and 36 with PJI）. We applied univariate analysis and multivariate logistic regression to analyze differences of coagulation factors between primary TJA and aseptic revision or PJI group. Receiver operating characteristic （ROC） curve and area under the curve （AUC） were used to measure the diagnostic value of coagulation factors in predicting PJI. ResultsCoagulation factors and their ratios including plasma fibrinogen （FBG）， prothrombin time （PT）， thrombin time （TT）， activated partial thromboplastin time （APTT）， platelet （PLT）， mean platelet volume （MPV）， platelet distribution width （PDW）， plateletcrit （PCT）， PLT / MPV， PLT / PDW and PLT / PCT were included in this study. High FGB level was strongly correlated with the risk of PJI compared to other coagulation factors. The optimal threshold value of FBG was 4.53 g/L with a sensitivity of 47.22%， a specificity of 93.07% （Primary TJA group vs. PJI group）. Similarly， the optimal threshold value of FBG was 4.44 g/L with a sensitivity of 47.22%， a specificity of 95.40% between the other two groups （Aseptic revision group vs. PJI group）. ROC curve analysis demonstrated moderate diagnostic performance of FBG （AUC value）， indicating a potential to be a diagnostic marker for PJI. ConclusionsFBG is significantly correlated with PJI and it can be used as a potential non-invasive marker for early detection. It may serve as a safe and cost-effective tool for assessing PJI in clinical work.

The Human Papillomavirus Infection Characteristics for Patients with Cervical Intraepithelial Neoplasia in Yunnan, China: A Sampling Survey Analysis.

Objective: This study aimed to analyze the status of human papillomavirus (HPV) infections in women in Yunnan in the south of China and their correlation with the grade of cervical intraepithelial neoplasia (CIN). Methods: A total of 281 patients with CIN and HPV infection, diagnosed at Kunming Kingmed Institute for Clinical Laboratory between January 2019 and June 2021, were enrolled as the subjects of the study and underwent HPV genotyping and cervical histopathology. Results: The mean age of the 281 patients was 42.3 years, and the median age was 42 years. There were 79 patients in the low-grade squamous intraepithelial lesion (LSIL) group, and 202 patients in the high-grade squamous intraepithelial lesion (HSIL) group. The proportion of 30-45 years old in HSIL group was 58%. Overall, single infections accounted for 76%, and HR-HPV infections accounted for 90.1%. The most common HR-HPV subtypes in the two CIN groups were almost the same, including HPV16, HPV58 and HPV52. The most common LR-HPV subtype in the two CIN groups was HPV43. There were no significant differences in ethnic and single or multiple infection rates among different CIN groups. Single infection of HPV43 and HPV81 was found in minority HSIL patients. Conclusion: HPV infection in Yunnan was dominated by single infection and HR-HPV. Patients aged 30 to 45 years were in the high incidence of HSIL, and the most common HR-HPV subtypes were HPV16, HPV58, and HPV52. Single LR-HPV infection exists in minority HSIL patients.

Clinicopathological and Gene Mutation Analysis of 27 Cases with Extranodal Rosai-Dorfman Disease.

Objective: To investigate the clinicopathological features, and mutations of NRAS, KRAS, BRAF and MAP2K1 genes in extranodal Rosai-Dorfman disease (RDD). Methods: The clinic opathological features of 27 patients with extranodal RDD were retrospectively analyzed, and the NRAS, KRAS, BRAF and MAP2K1 genes mutation were detected by Sanger sequencing. Results: The male to female ratio was 1.7:1. The average age was 46.9 years. There were skin lesions in 12 cases (44.4%) and head and neck lesions in 8 cases (29.6%). Microscopically, those patients with skin RDD had lesions characterized by clear and dark intervals and obvious emperipolesis, while in other parts, the background was more complex. About 21.1% (4/19) had mutations, including 3 mutations in NRAS 2 exon and 1 mutation in KRAS 2 exon. Two of the three NRAS mutations were located in the skin, accounting for 20% (2/10) of skin RDD. Conclusion: Extranodal RDD was more common in males than in females, and might occur in all ages, with a greater incidence in skin, head, and neck. Besides the obvious microscopic characteristics in those with skin RDD, the background of other parts was complex and easily missed or misdiagnosed. Some RDD with gene mutations, mainly in NRAS 2 exon, especially in skin RDD, support partial RDD is a clonal disease.

Dynamic responses of soil enzymes at key growth stages in rice after the in situ remediation of paddy soil contaminated with cadmium and arsenic.

The practical application of in situ remediation techniques requires an understanding of the dynamic changes in soil enzyme activity as indicators of soil fertility and health. Experiments were carried out in paddy soils co-contaminated with cadmium (Cd) and arsenic (As) at low (L) and high (H) levels. A calcium and iron (CaFe)-based amendment (limestone + iron powder + silicon fertilizer + calcium­magnesium-phosphate fertilizer) was applied to the soil at concentrations of 0, 450, and 900 g·m-2 (labeled CK, T1, and T2, respectively), and sampling was conducted at the tillering (TS), booting (BS), filling (FS), and mature (MS) stages. In soil L, urease activity increased significantly by 15.8% under T1 treatment at the MS, catalase activity increased significantly under T2 treatment by 52.4% at the FS and 25.9% at the MS, and acid phosphatase activity increased significantly by 50.1%-65.9% at the TS. For soil H, urease activity increased by maximum values of 101.6% and 28.6% at the FS and MS, respectively. Catalase activity increased by 29.0% at the MS under T2 treatment, and acid phosphatase activity increased by maximum values of 40.5%, 16.0%, and 53.9% at the BS, FS, and MS, respectively. The results indicate that the changes in soil enzyme activity were mainly related to the rice growth stage, soil pH, and available Cd and As after the application of Ca-Fe-based amendment. Overall, at the FS and MS, the amendment increased the soil pH, soil enzyme activity, and cation exchange capacity and reduced the available Cd and As, which reduced the Cd and As contents in brown rice.

A comparison of capillary electrophoresis and next-generation sequencing in the detection of immunoglobulin heavy chain H and light chain κ gene rearrangements in the diagnosis of classic hodgkin's lymphoma.

This study aimed to compare the application value of capillary electrophoresis and next-generation sequencing for immunoglobulin (IG) gene rearrangement in the diagnosis of classic Hodgkin's lymphoma. Twenty paraffin-embedded specimens from patients with classic Hodgkin's lymphoma were screened. For gene rearrangement detection, the ABI 3500 Genetic Analyzer and ABI Ion GeneStudio S5 Plus sequencing system were used, respectively, and the results were compared. Five cases with monoclonal rearrangements (25%, 5/20) were detected by Capillary Electrophoresis, and positivity for the FR1, FR2, FR3, and IGк loci was 5%, 10%, 10%, and 15%, respectively; 12 cases with monoclonal rearrangements (60%, 12/20) were detected by Next-generation Sequencing where the positivity of the above corresponding loci were 35%, 45%, 50%, and 30%, respectively. Among the 20 samples, 6 IGк clonal rearrangements were detected, and the usage frequency (66.7%) of IGкJ4 was the highest in the IGкJ subgroup. The usage frequency of IGкV1 and IGкV3 in the GкV sub-group was 33.3% and 33.3%, respectively. Twelve immunoglobulin heavy chain (IGH) clonal rearrangements were detected among the 20 samples, and the order of usage frequency in the IGH joining region J (IGHJ) subgroup was IGHJ4 > IGHJ5 > IGHJ6 > IGHJ3. The gene with the highest usage frequency in the IGH variable (IGHV) subgroup was IGHV3 (50%) and the percentage of IGHV mutations ranged from 0% ± 11.45% with an average frequency of 3.34%. Compared with Capillary Electrophoresis, Next-generation Sequencing showed a higher positivity in the detection of gene clonal rearrangements, was more accurate in the interpretation of results.

Self-registration of constant-step rotating Mueller matrix polarimeters.

Time-division framework is commonly used in Mueller matrix polarimeters (MPs), which takes extra numbers of images at the same position in an acquisition sequence. In this Letter, we utilize measurement redundancy to raise a unique loss function which can reflect and evaluate the degree of mis-registration of Mueller matrix (MM) polarimetric images. Further, we demonstrate that the constant-step rotating MPs have a self-registration loss function free from systematic errors. Based on this property, we propose a self-registration framework, which is able to apply efficient sub-pixel registration skipping the calibration procedure of MPs. It is demonstrated that the self-registration framework performs well for tissue MM images. By combining with other powerful vectorized super-resolution methods, the framework proposed in this Letter has the potential to handle more complicated registration problems.

The genomic architectures of tumour-adjacent tissues, plasma and saliva reveal evolutionary underpinnings of relapse in head and neck squamous cell carcinoma.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is characterised by a dismal prognosis; nonetheless, limited studies have unveiled the mechanisms underlying HNSCC relapse. METHODS: Next-generation sequencing was performed to identify the somatic mutations in 188 matched samples, including primary tumours, tumour-adjacent tissues (TATs), pre- and post-operative plasma, saliva and peripheral blood lymphocytes (PBLs) from 27 patients. The evolutionary relationship between TATs and tumours were analysed. The dynamic changes of tumour- and TAT-specific mutations in liquid biopsies were monitored together with survival analysis. RESULTS: Alterations were detected in 27 out of 27 and 19 out of 26 tumours and TATs, respectively. TP53 was the most prevalently mutated gene in TATs. Some TATs shared mutations with primary tumours, while some other TATs were evolutionarily unrelated to tumours. Notably, TP53 mutations in TATs are stringently associated with premalignant transformation and are indicative of worse survival (hazard ratio = 14.01). TAT-specific mutations were also detected in pre- and/or post-operative liquid biopsies and were indicative of disease relapse. CONCLUSIONS: TATs might undergo the processes of premalignant transformation, tumorigenesis and eventually relapse by either inheriting tumorigenic mutations from ancestral clones where the tumour originated or gaining private mutations independent of primary tumours. Detection of tumour- and/or TAT-specific genetic alterations in post-operative biopsies shows profound potential in prognostic use.

The Correlation Between Mutant p53 Protein Expression and Cell Atypia in Early Differentiated Gastric Adenocarcinoma.

OBJECTIVE: This study aims to explore the correlation between the expression of mutant p53 protein and cellular atypia in early differentiated gastric adenocarcinoma (DGA). METHODS: A total of 107 cases of early DGA samples resected by endoscopic submucosal dissection (ESD) were collected from the Pathology Department of Beijing Friendship Hospital from January 2018 to December 2019. The EnVision two-step immunohistochemical method was used to detect the expression of mutant p53 protein in these cancer tissues, and the correlation with cell atypia was analyzed. RESULTS: In early DGA tissues, the expression rate of mutant p53 protein was significantly higher than in normal gastric mucosa (P < 0.01). However, the expression of mutant p53 protein was not correlated to age or gender (P > 0.05) but to the location of the tumor, depth of invasion, and degree of differentiation (P < 0.01). The expression of mutant p53 protein was closely correlated to cell atypia. Furthermore, this was weakly positive in low-grade atypical adenocarcinoma but strongly positive or negative in high-grade atypical adenocarcinoma, and there was a significant difference between these two (P < 0.01). CONCLUSION: Mutant p53 protein is highly expressed in early DGA, which can be used as an auxiliary index for the diagnosis of early gastric cancer. The different expression patterns of mutant p53 protein in high-grade and low-grade atypical gastric cancers suggest that these may have different genetic changes.

Effect of DEC1 on the proliferation, adhesion, invasion and epithelial-mesenchymal transition of osteosarcoma cells.

Differentiated embryonic chondrocyte-expressed gene 1 (DEC1) is associated with various types of human cancer; however, there is limited data regarding the functions of DEC1 in osteosarcoma. The present study aimed to examine the expression of DEC1 in human osteosarcoma tissues and cell lines. Furthermore, the effects of DEC1 on the proliferation, adhesion, invasion and epithelial-mesenchymal transition (EMT) of osteosarcoma cells were investigated. Using reverse transcription-quantitative PCR and western blot analysis, it was found that the expression levels of DEC1 were higher in human osteosarcoma tissues and osteosarcoma cell lines than in the controls. Both gain- and loss-of-function experiments suggested that DEC1 promotes the proliferation, adhesion and invasion of osteosarcoma cells in vitro, as determined by MTT, cell adhesion and cell invasion assays, respectively. Additionally, DEC1 was found to upregulate the mesenchymal markers N-cadherin and vimentin, whilst downregulating the epithelial marker E-cadherin. In conclusion, this present study showed increased expression levels of DEC1 in human osteosarcoma tissues and cell lines, and identified that DEC1 may exert its effect on osteosarcoma progression by promoting cell proliferation, adhesion and invasion. Furthermore, DEC1 was shown to have an inducible effect on EMT in osteosarcoma cell lines, thus contributing to the aggressiveness of osteosarcoma cells. This initial study indicated that DEC1 may serve as a novel molecular target for the treatment of osteosarcoma.

SNHG1/miR-556-5p/TCF12 feedback loop enhances the tumorigenesis of meningioma through Wnt signaling pathway.

Meningioma, as a sort of the malignantly intracranial tumors, has captured public attention for its second-highest morbidity all over the world. Long noncoding RNAs (lncRNAs), including lncRNA SNHG1, have been well known as essential players in the development of diverse cancers. However, the biological effect and regulatory mechanism of SNHG1 have not been mentioned in meningioma. In this work, it was discovered that SNHG1 was overexpressed in meningioma cell lines. SNHG1 deficiency restrained cell growth as well as accelerated apoptosis. Then mechanism experiments demonstrated that SNHG1 functioned as the role of sponging miR-556-5p and negatively regulated miR-556-5p expression. Moreover, it was verified that TCF12 is the direct downstream target of miR-556-5p. Furthermore, SNHG1/miR-556-5p/TCF12 axis promoted cell proliferation and suppressed cell apoptosis in meningioma via activating the Wnt signaling pathway. In the end, it was confirmed that TCF12 expression was positively regulated by SNHG1, and TCF12 could promote transcription of SNHG1 through binding with the promoter region of SNHG1. In conclusion, the SNHG1/miR-556-5p/TCF12 feedback loop promotes the tumorigenesis of meningioma through the Wnt signaling pathway.

Clinical characteristics and genetic analysis of gene mutations in a Chinese pedigree with Peutz-Jeghers syndrome.

The genome-wide sequencing information of PJS is still lacking. Our result demonstrates that c.862+2T>C variant on STK11 as an important foundation of molecular mechanism in this familial PJS. Variants in KDR and MLL3 may play important roles in the initiation and development of this familial PJS polyps.

Development and evaluation of novel tumor-targeting paclitaxel-loaded nano-carriers for ovarian cancer treatment: in vitro and in vivo.

BACKGROUND: Ovarian cancer is the most leading cause of death and the third most common gynecologic malignancy in women. Traditional chemotherapy has inevitable drawbacks of nonspecific tumor targeting, high toxicity, and poor therapeutic efficiency. In order to overcome such shortcomings, we prepared a novel nano-carrier drug-delivery system to enhance the anti-tumor efficiency. METHODS: In vitro characterizations of nano-carriers were determined by TEM, DLS. Cell viability was measured by MTT method. RT-PCR was performed to measure the expression of FARα in three ovarian cancer cell lines. The drug-release study and the uptaken study were measured in vitro. The pharmacokinetic and the drug distribution study were verified by HPLC methods in vivo. The enhanced anti-tumor efficiency of FA-NP was evaluated by the tumor inhibitory rate in vivo. RESULTS: Paclitaxel (PTX)-loaded nanoparticles (NPs) (PTX-PEG-PLA-NP and PTX-PEG-PLA-FA-NP) were prepared successfully, and the drug-release study showed that the cumulative release rates of NP groups were much less than free PTX group. The pharmacokinetic study showed that the elimination phase of two kinds of NP groups were much longer than that of PTX group. The drug distribution in different tissues showed that the peak-reach time was 2 h in the PTX group and 6 h in both NP groups. All of these results confirmed the excellent slow-release effects of both kinds of nano-carriers. More importantly, we confirmed that PTX-PEG-PLA-FA-NP had greater uptake by SK-OV-3 cells than PTX-PEG-PLA-NP and free PTX in vitro. A drug-distribution study of tumor-bearing mice demonstrated that the PTX concentration of tumor tissues in the PTX-PEG-PLA-FA-NP group was 3 times higher than the other two groups. PTX-PEG-PLA-FA-NP was uptaken much more by SK-OV-3 cells than PTX-PEG-PLA-NP and free PTX. Eventually, based on the slow-release effect and tumor-targeting characteristics of PTX-PEG-PLA-FA-NP, a cytotoxicity test indicated that PTX-PEG-PLA-FA-NP was much more toxic to SK-OV-3 cells than the controls. The tumor inhibitory rate in the PTX-PEG-PLA-FA-NP group of tumor-bearing mice was about 1.5 times higher than the controls. The tumor targeting and anti-tumor efficiency of PTX-PEG-PLA-FA-NP were confirmed both in vitro and in vivo. CONCLUSIONS: We developed an ovarian cancer targeting nano-carrier drug delivery system successfully, which showed perfect ovarian cancer targeting and anti-tumor effect, thus have the potential to be a new therapy strategy for ovarian cancer patients.

Repalr of large-segmental femoral defects using lentivirus-mediated bone morphogenetic protein 2/bone marrow mesenchymal stem cells/demineralized bone matrix / 中国组织工程研究

BACKGROUND: Our research team has confirmed that compared to the adenoviral vector, transfection by lentiviral vector to rabbit bone marrow mesenchymal stem cells (BMSCs) is more effective that the expression of enhanced green fluorescent protein (EGFP)/bone morphogenetic protein 2 (BMP-2) can be persistent for a longer term. But further investigations are needed to explore whether BMSCs transfected with hBMP-2 through lentivirus combined with demineralized bone matrix (DBM) can promote bone defect repair. OBJECTIVE: To evaluate the effect of lentivirus-mediated hBMP-2/BMSCs/DBM (LV-hBMP-2/BMSCs/DBM) on the repair of large-segmental femoral defects and to explore the new treatments for large-segmental femoral defects. METHODS: Large-segmental bone defect models were made in the right femur of 48 New Zealand white rabbits by cutting the middle femoral bone and steel plate fixation. Then, animal models were randomly divided into four groups (n=12 per group) and implanted with nothing (control), DBM, hBMP-2/DBM, and LV-hBMP-2/BMSCs/DBM. Three rabbits from each group were sacrificed at 2, 4, 8 and 12 weeks after surgery to evaluate the repairing effect of femoral defects through hematoxylin-eosin staining, biomechanical analysis and radiological examination. RESULTS AND CONCLUSION: X-ray results revealed that osteotylus formed in all the four groups to different extents, and Lane - Sandhu X-ray scores were ranked as follows: control group < DBM group < hBMP-2/DBM group < LV-hBMP-2/BMSCs/DBM group (P < 0.05). Findings from the three-point bending test showed that the maximum load of the LV-hBMP-2/BMSCs/DBM group was significantly higher than that of the hBMP-2/DBM group, but is still lower than that of the normal femur at 8 and 12 weeks after modeling (P < 0.05). Hematoxylin-eosin staining results revealed that a few trabecular bones arranged disorderedly and a large amount of fibrous tissues in the control group; the DBM scaffold was basically degraded in the DBM group presenting with partially disordered trabecular bones and a large amount of fibrous tissues; the trabecular bones in the bone defect area were basically connected into line to start the shaping of the cortical bone, and recanalization of the medullary cavity was insignificant in the hBMP-2/DBM group; new cortical bone formed in the bone defect area and the medullary cavity was recanalized in the LV-hBMP-2/BMSCs/DBM group. These findings indicate that LV-hBMP-2/BMSCs/DBM can produce a large amount of calluses, promote formation of new cortical bone, and promote bone conduction, bone induction and osteogenesis after implantation into the bone defect; and this material has good repairing effect on large-segmental femoral defects of rabbits.

Robust MR image segmentation using the trimmed likelihood estimator in asymmetric Student's-t mixture model.

Finite mixture model (FMM) has been widely used for unsupervised segmentation of magnetic resonance (MR) images in recent years. However, in real applications, the distribution of the observed data usually contains an unknown fraction of outliers, which would interfere with the estimation of the parameters of the mixture model. The statistical model-based technique which provides a theoretically well segmentation criterion in presence of outliers is the mixture modeling and the trimming approach. Therefore, in this paper, a robust estimation of asymmetric Student's-t mixture model (ASMM) using the trimmed likelihood estimator for MR image segmentation has been proposed. The proposed method is supposed to discard the outliers, and then to estimate the parameters of the ASMM with the remaining samples. The advantages of the proposed algorithm are that its robustness to dispose the disturbance of outliers and its flexibility to describe various shapes of data. Finally, expectation-maximization (EM) algorithm is adopted to maximize the log-likelihood and to obtain the estimation of the parameters. The experimental results show that the proposed method has a better performance on the segmentation of synthetic data and real MR images.

Image recognition with missing-features based on gaussian mixture model and graph constrained nonnegative matrix factorization.

The demand for automatically recognizing medical images for screening, reference and management is growing faster than ever. Missing data phenomenon in medical image applications is common existence, and it could be inevitable. In this paper, we have addressed the problem of recognizing medical images with missing-features via Gaussian mixture model (GMM)-based approach. Since training a GMM by directly using high-dimensional feature vectors will result in instability, we have proposed a novel strategy to train the GMM from the corresponding reduced-dimensional one. The proposed method contains training and test phases. The former contains feature extraction, graph constrained nonnegative matrix factorization (NMF), GMM training, and the alternating expectation conditional maximization (AECM) for extending the reduced-dimensional GMM. In test phase, two methods, marginalizing GMM using Bayesian decision (MGBD) and conditional mean imputation (CMI), are applied to impute missing-features. Posterior probability of test images is calculated to identify objects. Experimental results on three real datasets demonstrate the feasibility and efficiency of the proposed scheme.

Comparison of lentiviral vector and adenoviral vector mediated gene transfer into rabbit bone marrow mesenchymal stem cells / 中国组织工程研究

BACKGROUND: Both lentiviral vector and adenoviral vector are considered as good vectors for gene mediation, and their differences in transferring bone morphogenetic protein 2 (BMP-2) into rabbit bone marrow mesenchymal stem cells (BMSCs) are unclear. OBJECTIVE: To compare the duration, efficiency and the deviation of exogenous gene expression after rabbit BMSCs transfection using lentiviral vector and adenoviral vector which are used to mediate enhanced green fluorescent proteins (EGFP) and BMP-2. METHODS: Rabbit BMSCs at passage 5 were exposed to Ad-EGFP-BMP-2 (group A) or Lenti-EGFP-BMP-2 (group B) with multiplicity of infection of 100, as transfection groups. And in control group (group C), the same quality of culture medium was required equivalent to the groups A and B. The expression of EGFP was observed by inverted fluorescence microscope at various time intervals. And the expression of exogenous gene BMP 2 in cells was detected and analyzed by immunohistochemical staining at 72 hours after transfection as well as by western blot at 72 hours, 1, 3 weeks after transfection. RESULTS AND CONCLUSION: The intense green fluorescence emerged under the microscope at 24-48 hours after transfection in group A, which was stronger than group B, reached the peak at 72 hours, and then decreased at 1 week until disappearance at 3 weeks. No EGFP expression was detected in group C. High expression of BMP-2 was found in group A but was dramatically downregulated after 1 week. Group B showed the high expression of EGFP/BMP-2 persisted for a longer period after transfected that even lasted for 3 weeks. Overall, the lentiviral vector and adenoviral vector can efficiently transfect rabbit BMSCs and stably express the target gene of EGFP/BMP-2. Under the same MOI, compared to the adenoviral vector, transfection of lentiviral vector to rabbit BMSCs is more effectively and expression of EGFP/BMP-2 can be persistent in a longer term.

MicroRNA-dependent roles of Drosha and Pasha in the Drosophila larval ovary morphogenesis.

The Drosophila larval ovary morphogenesis mainly involves coordinated development of somatic and germ cell lineages that is essential for forming a correct number of niche-germline stem cell (GSC) units (ovarioles) in the adult ovary. Ecdysone, Insulin, Activin, Dpp and EGFR signaling pathways form a regulatory network that orchestrates ovarian soma and germ line throughout larval development. Identification and characterization of additional genes or machineries involved in this process will provide more insights into the underlying mechanisms. Here, we show that the core microRNA (miRNA) pathway components Drosha and Pasha are required for coordinated development of somatic and germ cell precursors in the larval ovary. Drosha or pasha mutants display defective proliferation of primordial germ cells (PGCs), the precursors of GSCs prior to late third larval instar (LL3) and promoted PGC differentiation at LL3. In the mean time, loss of Drosha or Pasha function perturbs somatic precursor development, causing defects in formation of terminal filaments (TFs), a major composition of the GSC niche at LL3, as well as in TF precursor accumulation at early larval stages. Comparative analysis of the mutant phenotypes reveals that three other key miRNA pathway components, Dicer-1 (Dcr-1), Loquacious (Loqs) and Argonaute-1 (Ago-1) have similar effects as Drosha and Pasha indicated above, suggesting a role of the canonical miRNA pathway in the ovary development. Furthermore, genome-wide screening and genetic studies identify a set of Drosha-controlled miRNAs including miR-8, miR-14, miR-33, miR-184, miR-317 and let-7-C that function in this gonadogenesis. Taken together, this study provides the first ever demonstration that miRNA-mediated regulation is involved in the Drosophila larval ovary morphogenesis.