An Anti-Noise Convolutional Neural Network for Bearing Fault Diagnosis Based on Multi-Channel Data.

In real world industrial applications, the working environment of a bearing varies with time, and some unexpected vibration noises from other equipment are inevitable. In order to improve the anti-noise performance of neural networks, a new prediction model and a multi-channel sample generation method are proposed to address the above problem. First, we proposed a multi-channel sample representation method based on the envelope time-frequency spectrum of a different channel and subsequent three-dimensional filtering to extract the fault features of samples. Second, we proposed a multi-channel data fusion neural network (MCFNN) for bearing fault discrimination, where the dropout technique is used in the training process based on a dataset with a wide rotation speed and various loads. In a noise-free environment, our experimental results demonstrated that the proposed method can reach a higher fault classification of 99.00%. In a noisy environment, the experimental results show that for the signal-to-noise ratio (SNR) of 0 dB, the fault classification averaged 11.80% higher than other methods and 32.89% higher under a SNR of -4 dB.

FGD5­AS1 is an oncogenic lncRNA in pancreatic cancer and regulates the Wnt/ß­catenin signaling pathway via miR­577.

The objective of the present study was to clarify the expression characteristics of long non­coding RNA (lncRNA) FGD5 antisense RNA 1 (FGD5­AS1) in pancreatic cancer, as well as its biological function and underlying mechanism. Reverse transcription­quantitative polymerase chain reaction (RT­qPCR) was utilized for the detection of FGD5­AS1 and microRNA (miR)­577 expression levels in pancreatic cancer tissues. Transfection was performed to upregulate or downregulate FGD5­AS1 in pancreatic cancer cell lines. MTT and Transwell assays were then utilized to detect the proliferation, migration and invasion of cancer cells, respectively. Subsequently, dual­luciferase reporter gene assay, RNA immunoprecipitation assay, RNA pull­down assay, RT­qPCR, western blotting, and Pearson's correlation analysis were employed to confirm the regulatory relationships among FGD5­AS1, miR­577, low­density lipoprotein receptor­related protein 6 (LRP6) and ß­catenin. Western blotting was employed to determine the expression levels of Axin2, cyclin D1 and c­Myc. The expression level of FGD5­AS1 was upregulated in pancreatic cancer tissues and cell lines. FGD5­AS1 knockdown inhibited pancreatic cancer cell proliferation, migration and invasion. By contrast, miR­577 was significantly inhibited in pancreatic cancer cells and tissues; its downregulation promoted pancreatic cancer cell proliferation, migration and invasion, and reversed the effects of FGD5­AS1 knockdown on pancreatic cancer cells. In addition, it was revealed that miR­577 was a target of FGD5­AS1, and FGD5­AS1 could modulate the expression levels of LRP6, ß­catenin, Axin2, cyclin D1 and c­Myc via suppressing miR­577. In conclusion, in pancreatic cancer, highly expressed FGD5­AS1 activated the Wnt/ß­catenin signaling and promoted cancer cell proliferation, migration and invasion via suppression of miR­577.

Administration of isoliquiritigenin prevents nonalcoholic fatty liver disease through a novel IQGAP2-CREB-SIRT1 axis.

Isoliquiritigenin (ISO) is a flavonoid extracted from the root of licorice, which serves various biological and pharmacological functions including antiinflammatory, antioxidation, liver protection, and heart protection. However, the mechanism of its action remains elusive and the direct target proteins of ISO have not been identified so far. Through cell-based screening, we identified ISO as a potent lipid-lowering compound. ISO treatment successfully ameliorated fatty acid-induced cellular lipid accumulation and improved nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) by increasing PPARα-dependent lipid oxidation and decreasing SREBPs-dependent lipid synthesis. Both these signaling required the activation of SIRT1. Knockdown of SIRT1 resulted in the reversal of ISO beneficiary effects suggesting that the lipid-lowering activity of ISO was regulated by SIRT1 expression. To identify the direct target of ISO, limited proteolysis combined with mass spectrometry (LiP-SMap) strategy was applied and IQGAP2 was identified as the direct target for ISO in regulating lipid homeostasis. In the presence of ISO, both mRNA and protein levels of SIRT1 were increased; however, this effect was abolished by blocking IQGAP2 expression using siRNA. To explore how IQGAP2 regulated the expression level of SIRT1, proteome profiler human phospho-kinase array kit was used to reveal possible phosphorylated kinases and signaling nodes that ISO affected. We found that through phosphorylation of CREB, ISO transduced signals from IQGAP2 to upregulate SIRT1 expression. Thus, we not only demonstrated the molecular basis of ISO in regulating lipid metabolism but also exhibited for the first time a novel IQGAP2-CREB-SIRT1 axis in treating NAFLD/NASH.

Cyclic helix B peptide alleviates sepsis-induced acute lung injury by downregulating NLRP3 inflammasome activation in alveolar macrophages.

Acute lung injury (ALI) exhibits high clinical morbidity and mortality rates. Our previous study has indicated that the novel proteolysis-resistant cyclic helix B peptide (CHBP) exerts an anti-inflammatory effect in mice with AKI. In the present study, we evaluated the effect of CHBP in an in vivo sepsis-induced ALI model and in vitro using lipopolysaccharide (LPS) and ATP stimulated bone marrow-derived macrophages (BMDMs). For in vivo experiments, mice were randomly divided into three groups: 1) sham; 2) LPS; and 3) LPS + CHBP (n = 6). All relevant data were collected after 18 h. Following CHBP treatment, the lung function of the mice was significantly improved compared to the LPS group. CHBP administration inhibited interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α production at both the protein and mRNA levels. Additionally, following CHBP treatment, the population of pulmonary macrophages decreased. Simultaneously, the proportion of caspase-1-activated alveolar macrophages was also decreased after CHBP treatment. The protein levels of NLRP3 and cleaved caspase-1 were attenuated in the lung tissue following CHBP treatment. In in vitro experiments, CHBP treatment decreased NLRP3 inflammasome expression and downstream IL-1ß secretion, consistent with the in vivo results. In addition, CHBP reversed nuclear factor (NF)-κB and I-κB phosphorylation with a significant dose-dependent effect. Therefore, these findings suggest the potential of CHBP as a therapeutic agent in sepsis-induced ALI owing to inhibition of the NLRP3 inflammasome via the NF-κB pathway in macrophages.

Transorbital nonmissile penetrating brain injury: Report of two cases.

BACKGROUND: Penetrating brain injury (PBI) is an uncommon emergency in neurosurgery, and transorbital PBI is a rare type of PBI. Reasonable surgical planning and careful postoperative management can improve the prognosis of patients. CASE SUMMARY: The first case is a 68-year-old male patient who was admitted to the hospital because a branch punctured his brain through the orbit for approximately 9 h after he unexpectedly fell while walking. After admission, the patient underwent emergency surgical treatment and postoperative anti-infection treatment. The patient was able to follow instructions at a 4-mo follow-up review. The other case is a 46-year-old male patient who was admitted to the hospital due to an intraorbital foreign body caused by a car accident, after which the patient was unconscious for approximately 6 h. After admission, the patient underwent emergency surgical treatment and postoperative anti-infection treatment. The patient could correctly answer questions at a 3-mo follow-up review. CONCLUSION: Transorbital PBI is a rare and acute disease. Early diagnosis, surgical intervention, and application of intravenous antibiotics can improve the prognosis and quality of life of patients.

Understanding Gene Therapy in Acute Respiratory Distress Syndrome.

Acute Respiratory Distress Syndrome (ARDS) and its complications remain lifethreatening conditions for critically ill patients. The present therapeutic strategies such as prone positioning ventilation strategies, nitric oxide inhalation, restrictive intravenous fluid management, and extracorporeal membrane oxygenation (ECMO) do not contribute much to improving the mortality of ARDS. The advanced understanding of the pathophysiology of acute respiratory distress syndrome suggests that gene-based therapy may be an innovative method for this disease. Many scientists have made beneficial attempts to regulate the immune response genes of ARDS, maintain the normal functions of alveolar epithelial cells and endothelial cells, and inhibit the fibrosis and proliferation of ARDS. Limitations to effective pulmonary gene therapy still exist, including the security of viral vectors and the pulmonary defense mechanisms against inhaled particles. Here, we summarize and review the mechanism of gene therapy for acute respiratory distress syndrome and its application.

Efficacy of methylphenidate for the treatment of mental sequelae after traumatic brain injury.

BACKGROUND: This study aimed to evaluate the effect of methylphenidate for treating mental sequelae after traumatic brain injury (TBI). METHODS: Thirty-six patients with TBI were randomly divided into the intervention group and placebo group. The participants in the intervention group received methylphenidate, while subjects in the placebo group were administered a placebo. This study was conducted from January 2014 to December 2016. The outcome measurements included Mental Fatigue Scale, Choice Reaction Time, Compensatory Tracking Task, Mental Arithmetic Test, Digit Symbol Substitution Test, Mini-Mental State Examination (MMSE), Beck Depression Inventory (BDI), and Hamilton Rating Scale for Depression. In addition, safety was also recorded and assessed. RESULTS: A total of 33 subjects completed the study. Methylphenidate showed greater efficacy than placebo, with decreased scores on the Mental Fatigue Scale, Choice Reaction Time, and Compensatory Tracking Task in the intervention group compared to the placebo group (P < .01, respectively). Furthermore, increased scores on the Mental Arithmetic Test, Digit Symbol Substitution Test, and MMSE in the intervention group, compared to those in the placebo group (P < .01 respectively), were observed. In addition, a significant difference in the scores on the BDI (P = .04) and Hamilton Rating Scale for Depression (P = .005) was observed between the 2 groups. The safety at the end of the 30 week-treatment was similar between the 2 groups (P > .05). CONCLUSION: The results of this study demonstrated that methylphenidate could effectively improve mental fatigue and cognitive functions in patients with TBI.

Characteristics Analysis of the Thyroid Gland Surface of Normal Human with Fourier Transform Infrared (FTIR) Spectra.

In order to obtain 240 cases of the surface Fourier transform infrared (FTIR) spectra of normal human thyroid gland, 120 healthy volunteers were enrolled in this study and scanned by using two mid-infrared optical fibers equipped with an attenuated total reflectance (ATR) to probe through the skin of two lobes of thyroid gland. Then whether there were differences between the surface FTIR spectra of the right lobe and that of the left part of the normal human thyroid gland was explored by comparing the 35 variables of 12 bands, including peak positions, relative intensity ratios and full width at half maximum of FTIR spectrums. Also the spectra characteristics of unique absorbent bands that represent changes of structure and quantity of variance biochemical substances such as nucleic acids, proteins and carbohydrates were illustrated. Results indicated that the surface FTIR spectra of the right part and that of the left part of the normal human thyroid gland were generally coincided, with statistically significant differences in four spectrum parameters, includingF1 640, P2 920, P1 040 and I2 920/I1 460. A series of data about the 90% normal reference range of the unique spectrum parameters in the surface FTIR spectra of normal human thyroid gland was gained, and a standard average infrared spectrogram which can fully represent the basic features of normal human thyroid gland was plotted. The conclusions above could be used as a reference for clinical diagnosis of thyroid diseases with FTIR spectroscopy.

Oddi sphincter preserved cholangioplasty with hepatico-subcutaneous stoma for hepatolithiasis.

AIM: To evaluate the long-term outcomes of Oddi sphincter preserved cholangioplasty with hepatico-subcutaneous stoma (OSPCHS) and risk factors for recurrence in hepatolithiasis. METHODS: From March 1993 to December 2012, 202 consecutive patients with hepatolithiasis underwent OSPCHS at our department. The Oddi sphincter preserved procedure consisted of common hepatic duct exploration, stone extraction, hilar bile duct plasty, establishment of subcutaneous stoma to the bile duct. Patients with recurrent stones can undergo stone extraction and/or biliary drainage via the subcutaneous stoma which can be incised under local anesthesia. The long-term results were reviewed. Cox regression model was employed to analyze the risk factors for stone recurrence. RESULTS: Ninety-seven (48.0%) OSPCHS patients underwent hepatic resection concomitantly. The rate of surgical complications was 10.4%. There was no perioperative death. The immediate stone clearance rate was 72.8%. Postoperative cholangioscopic lithotomy raised the clearance rate to 97.0%. With a median follow-up period of 78.5 mo (range: 2-233 mo), 24.8% of patients had recurrent stones, 2.5% had late development of cholangiocarcinoma, and the mortality rate was 5.4%. Removal of recurrent stones and/or drainage of inflammatory bile via subcutaneous stoma were conducted in 44 (21.8%) patients. The clearance rate of recurrent stones was 84.0% after subsequent choledochoscopic lithotripsy via subcutaneous stoma. Cox regression analysis showed that residual stone was an independent prognostic factor for stone recurrence. CONCLUSION: In selected patients with hepatolithiasis, OSPCHS achieves excellent long-term outcomes, and residual stone is an independent prognostic factor for stone recurrence.

Correlation between microRNA-21 and expression of Th17 and Treg cells in microenvironment of rats with hepatocellular carcinoma.

OBJECTIVE: To study the correlation between miR-21 and Treg/Th17 ratio in the microenvironment of rats with hepatocellular carcinoma. METHODS: Diethylnitrosamine was used to build the hepatocellular carcinoma model of rats; the content of Treg cells and Th17 cells and the expression of miR-21 in the peripheral blood of rats with hepatocellular carcinoma were detected. The statistical analysis was performed on the correlation between miR-21 expression and Treg/Th17 ratio. RESULTS: Hepatocellular carcinoma model of rats was successfully constructed. The proportion of Th17 cells among all CD4(+)T cells in the peripheral blood of rats with hepatocellular carcinoma was 5.319%, which was higher than the control group; while the proportion of Treg cells was 9.472%, which was higher than the control group. Treg/Th17 ratio in the model group was 1.781, compared with 1.478 in the control group. The expression of miR-21 was increased in the peripheral blood of rats with hepatocellular carcinoma and it showed a positive correlation with the ratio of Treg/Th17. CONCLUSIONS: There is a positive correlation between the expression level of miR-21 and the ratio of Treg/Th17.

Phloroglucinol protects the urinary bladder via inhibition of oxidative stress and inflammation in a rat model of cyclophosphamide-induced interstitial cystitis.

BACKGROUND: Phloroglucinol plays an important role in oxidative stress and inflammatory responses. The effects of phloroglucinol have been proven in various disease models. The aim of the present study was to investigate the efficacy and possible mechanisms of phloroglucinol in the treatment of interstitial cystitis (IC). METHODS: Thirty-two female Sprague-Dawley (SD) rats were used in this study. IC was induced by intraperitoneal injection of cyclophosphamide (CYP). Rats were randomly allocated to one of four groups (n = 8 per group): A control group, which was injected with saline (75 mg/kg; i.p.) instead of CYP on days 1, 4, and 7; a chronic IC group, which was injected with CYP (75 mg/kg; i.p.) on days 1, 4, and 7; a high-dose (30 mg/kg) phloroglucinol-treated group; and a low-dose (15 mg/kg) phloroglucinol-treated group. On day 8, the rats in each group underwent cystometrography (CMG), and the bladders were examined for evidence of oxidative stress and inflammation. Statistical analysis was performed by analysis of variance (ANOVA) followed by least square difference multiple comparison post-hoc test. RESULTS: Histological evaluation showed that bladder inflammation in CYP-treated rats was suppressed by phloroglucinol. CMG revealed that the CYP treatment induced overactive bladder in rats that was reversed by phloroglucinol. Up-regulated tumor necrosis factor-α and interleukin-6 expression in the CYP-treated rats were also suppressed in the phloroglucinol treated rats. CYP treatment significantly increased myeloperoxidase activity as well as the decreased activities of catalase of the bladder, which was reversed by treatment with phloroglucinol. CONCLUSIONS: The application of phloroglucinol suppressed oxidative stress, inflammation, and overactivity in the bladder. This may provide a new treatment strategy for IC.

Clinical manifestations and imaging characteristics of gliomatosis cerebri with pathological confirmation.

OBJECTIVE: To explore the clinical manifestations and imaging characteristics of gliomatosis cerebri to raise the awareness and improve its diagnostic accuracy for patients. MATERIALS AND METHODS: Clinical data, imaging characteristics and pathological examination of 12 patients with GC from Jan., 2008 to Jan., 2012 were analyzed retrospectively. RESULTS: Patients with GC were clinically manifested with headache, vomiting, repeated seizures, fatigue and unstable walking, most of whom had more than 2 lesions involving in parietal lobe, followed by temporal lobe, frontal lobe, periventricular white matter and corpus callosum. Magnetic resonance imaging (MRI) showed diffuse distribution, T1-weighted images (T1WI) with equal and low signals and T2-weighted images (T2WI) with bilateral symmetrical high diffuse signals. There was no reinforcement by enhancement scanning and signals were different in diffusion-weighted images (DWI). The higher the tumor staging, the stronger the signals. Pathological examination showed neuroastrocytoma in which tumor tissues were manifested by infiltrative growth in blood vessels and around neurons. CONCLUSIONS: In clinical diagnosis of GC, much attention should be paid to the diffuse distribution of imaging characteristics, incomplete matching between clinical and imaging characteristics and confirmation by combining with histopathological examination.

Adaptive quasi-Newton algorithm for source extraction via CCA approach.

This paper addresses the problem of adaptive source extraction via the canonical correlation analysis (CCA) approach. Based on Liu's analysis of CCA approach, we propose a new criterion for source extraction, which is proved to be equivalent to the CCA criterion. Then, a fast and efficient online algorithm using quasi-Newton iteration is developed. The stability of the algorithm is also analyzed using Lyapunov's method, which shows that the proposed algorithm asymptotically converges to the global minimum of the criterion. Simulation results are presented to prove our theoretical analysis and demonstrate the merits of the proposed algorithm in terms of convergence speed and successful rate for source extraction.

[Recent progress in diagnosis of malignant tumors by Fourier transform infrared spectroscopy].

Malignant tumors pose a serious threat to mankind health and life. As a result, early diagnosis is very important. In recent years, Fourier transform infrared spectroscopy has shown enormous development potential of cancer diagnosis. Compared with traditional methods, this technology has apparent advantages in the aspects of accuracy, rapidity, noninvasion, in situ, cheapness, automation, replication, without pretreatment and early diagnosis at the molecular level. This paper summarized study progress that FTIR technology applied in diagnosis of respiratory system tumor, digestive system tumor, urinary genital system tumor, brain tumor, skin tumor and blood system tumor, and combined with the international present state of clinical medicine, spectroscopy and chemometrics, five prospects were put forward: expand the sample size and undertake multi-center study; combined with endoscopy and puncture biopsy to guide real-time in situ diagnosis and biopsy during surgery; further automated; find more efficient chemometric methods; the identification of individual parameters has yet to be confirmed by further studies. With the further development and improvement of FTIR technology, it will become an important method for the diagnosis of malignant tumors, and may even as a routine screening tool applied to stage and grade the tumors.

Combination of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography and magnetic resonance imaging is an optimal way to evaluate rheumatoid arthritisin rats dynamically.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic, systemic autoimmune inflammatory disorder. Many methods have been used to observe the progress of RA. The purpose of this study was to observe the progress of RA in rats with 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT), magnetic resonance (MR) imaging and arthritis score, and analyze the relationships among different methods in evaluation of RA. METHODS: Sixteen healthy Sprague Dawley (SD) rats about 8-week old were randomly assigned to a RA group and a control group. Bovine type II emulsified incomplete Freud's adjuvant was used to induce arthritis in the RA group. Arthritis score of the rats in two groups were recorded, and (18)F-FDG PET/CT, MR imaging were performed both on the corresponding rats every 3 days. All the rats were sacrificed at week 5, and histopathological examination was performed on rat knees stained with haematoxylin and eosin. RESULTS: The arthritis score and the standard uptake value (SUV) of knee joints in RA rats increased with the progression of arthritis gradually. Both peaks of arthritis score and SUV appeared at 21 days after the first immune injection, then the arthritis score and SUV of knee joints decreased slowly. The arthritis scores of knee joints in RA rats were positively correlated with their SUV changes. The MR images were confirmed by the histopathological studies. CONCLUSION: PET/CT can detect the earliest molecular metabolism changes of RA, and MR imaging can follow up the dynamical anatomical changes of RA, all of which indicated that PET/CT and MR imaging may be applied as useful tools to monitor the progress of RA.

Quantitative T2 mapping evaluation for articular cartilage lesions in a rabbit model of anterior cruciate ligament transection osteoarthritis.

BACKGROUND: Quantitative T2 mapping has been a widely used method for the evaluation of pathological cartilage properties, and the histological assessment system of osteoarthritis in the rabbit has been published recently. The aim of the study was to investigate the effectiveness of quantitative T2 mapping evaluation for articular cartilage lesions of a rabbit model of anterior cruciate ligament transection (ACLT) osteoarthritis. METHODS: Twenty New Zealand White (NZW) rabbits were divided into ACLT surgical group and sham operated group equally. The anterior cruciate ligaments of the rabbits in ACLT group were transected, while the joints were closed intactly in sham operated group. Magnetic resonance (MR) examinations were performed on 3.0T MR unit at week 0, week 6, and week 12. T2 values were computed on GE ADW4.3 workstation. All rabbits were killed at week 13, and left knees were stained with Haematoxylin and Eosin. Semiquantitative histological grading was obtained according to the osteoarthritis cartilage histopathology assessment system. Computerized image analysis was performed to quantitate the immunostained collagen type II. RESULTS: The average MR T2 value of whole left knee cartilage in ACLT surgical group ((29.05±12.01) ms) was significantly higher than that in sham operated group ((24.52±7.97) ms) (P=0.024) at week 6. The average T2 value increased to (32.18±12.79) ms in ACLT group at week 12, but remained near the baseline level ((27.66±8.08) ms) in the sham operated group (P=0.03). The cartilage lesion level of left knee in ACLT group was significantly increased at week 6 (P=0.005) and week 12 (P<0.001). T2 values had positive correlation with histological grading scores, but inverse correlation with optical densities (OD) of type II collagen. CONCLUSION: This study demonstrated the reliability and practicability of quantitative T2 mapping for the cartilage injury of rabbit ACLT osteoarthritis model.

Iterative algorithm for joint zero diagonalization with application in blind source separation.

A new iterative algorithm for the nonunitary joint zero diagonalization of a set of matrices is proposed for blind source separation applications. On one hand, since the zero diagonalizer of the proposed algorithm is constructed iteratively by successive multiplications of an invertible matrix, the singular solutions that occur in the existing nonunitary iterative algorithms are naturally avoided. On the other hand, compared to the algebraic method for joint zero diagonalization, the proposed algorithm requires fewer matrices to be zero diagonalized to yield even better performance. The extension of the algorithm to the complex and nonsquare mixing cases is also addressed. Numerical simulations on both synthetic data and blind source separation using time-frequency distributions illustrate the performance of the algorithm and provide a comparison to the leading joint zero diagonalization schemes.

Genotypic characteristics of the rrn operon and genome of indigenous soybean Bradyrhizobia in cropping zones of China.

Four genetic assays, 16S rRNA restriction fragment length polymorphism (RFLP), 16S rRNA sequencing, 16S-23S rRNA intergenetic spacer (IGS) RFLP, and amplified fragment length polymorphism (AFLP), were conducted to determine the genotypic characteristics of 44 indigenous strains of Bradyrhizobium from soybean (Glycine max L.) cropping zones of China. The results generated from different assays showed that soybean bradyrhizobial isolates comprised four genomic groups. Group I was composed of strains mainly isolated from the North and Northeast plains of China. All four assays confirmed this group as phylogenetically divergent from all the reference strains. Strains of the group may represent a new species. Strains in Group II isolated from a variety of geographic regions were ascribed to B. liaoningense. Strains in Group III, mainly isolated from Central and East China, were closely related to the reference strains of B. japonicum. Strains in Group IV belonged to B. elkanii.

[Genetic diversity and phylogeny of soybean bradyrhizobia isolated from south and north region of China].

Studies on genetic diversity and phylogeny of soybean bradyrhizobia isolated from south and north region of China were investigated through 16S rRNA gene PCR RFLP, 16S rRNA gene sequencing and 16S-23S rRNA IGS PCR RFLP assays. Results of 16S rRNA gene PCR RFLP and 16S rRNA gene sequencing analysis reveal that strains tested are ascribed into Bradyrhizobium japonicum and B. elkanii species. B. japonicum is the dominant species and accounts for 91% of strains tested, but B. elkanii just up to 9%, which shows poor genetic diversity. Results of 16S-23S rRNA IGS PCR RFLP assays reveal that strains belonged to B. japonicum can be divided into Group I and Group HIIat the 69 similarity. Group I consists of strains from northern China, and Group 1I consists of strains from southern China, which demonstrates geographical effect on genetic diversity of bradyrhzobia. Results of 16S-23S rRNA IGS PCR RFLP further reflects that strains of Group I and Group II are phylogenetically different with type or representative strains USDA6, USDA110 and USDA122 of B. japonicum.

[Studies on genetic diversity and phylogeny of slow-growing rhizobia isolated from Vigna radiata at main ecotypes of China].

Studies on genetic diversity and phylogeny of slow-growing rhizobia isolated from Vigna radiata at main ecotypes of China were conducted by using 16S rRNA gene PCR-RFLP, 16S rRNA gene sequencing and 16S-23S rRNA IGS PCR-RFLP assays. Results of 16S rRNA gene PCR RFLP analysis reveal that all the strains tested are clustered into three groups at the similarity of 76%. Group I contains 13 slow-growing rhizobia tested including LYG1; Group II consists of 21 strains tested and the type strains of B. japonicum and B. liaoningense, and 10 tested strains isolated from Guangdong, Guangxi and the type strain of B. elkanii compose Group III . The results of 16S-23S rRNA IGS PCR-RFLP show that strains tested could be divided into A and B groups, which could be correspondently subdivided into A I , A II , AIII , BI and B II subgroups at the similarity of 85% . Compared with 16S rRNA PCR-RFLP, IGS RFLP assay show higher resolution, strains and reference strains tested can be divided into 21 IGS RFLP patterns. The strains isolated from Xinjiang, Guangdong and Guangxi regions show obvious geographical effect on genetic diversity.