Multiplex genetic manipulations in Clostridium butyricum and Clostridium sporogenes to secrete recombinant antigen proteins for oral-spore vaccination.

BACKGROUND: Clostridium spp. has demonstrated therapeutic potential in cancer treatment through intravenous or intratumoral administration. This approach has expanded to include non-pathogenic clostridia for the treatment of various diseases, underscoring the innovative concept of oral-spore vaccination using clostridia. Recent advancements in the field of synthetic biology have significantly enhanced the development of Clostridium-based bio-therapeutics. These advancements are particularly notable in the areas of efficient protein overexpression and secretion, which are crucial for the feasibility of oral vaccination strategies. Here, we present two examples of genetically engineered Clostridium candidates: one as an oral cancer vaccine and the other as an antiviral oral vaccine against SARS-CoV-2. RESULTS: Using five validated promoters and a signal peptide derived from Clostridium sporogenes, a series of full-length NY-ESO-1/CTAG1, a promising cancer vaccine candidate, expression vectors were constructed and transformed into C. sporogenes and Clostridium butyricum. Western blotting analysis confirmed efficient expression and secretion of NY-ESO-1 in clostridia, with specific promoters leading to enhanced detection signals. Additionally, the fusion of a reported bacterial adjuvant to NY-ESO-1 for improved immune recognition led to the cloning difficulties in E. coli. The use of an AUU start codon successfully mitigated potential toxicity issues in E. coli, enabling the secretion of recombinant proteins in C. sporogenes and C. butyricum. We further demonstrate the successful replacement of PyrE loci with high-expression cassettes carrying NY-ESO-1 and adjuvant-fused NY-ESO-1, achieving plasmid-free clostridia capable of secreting the antigens. Lastly, the study successfully extends its multiplex genetic manipulations to engineer clostridia for the secretion of SARS-CoV-2-related Spike_S1 antigens. CONCLUSIONS: This study successfully demonstrated that C. butyricum and C. sporogenes can produce the two recombinant antigen proteins (NY-ESO-1 and SARS-CoV-2-related Spike_S1 antigens) through genetic manipulations, utilizing the AUU start codon. This approach overcomes challenges in cloning difficult proteins in E. coli. These findings underscore the feasibility of harnessing commensal clostridia for antigen protein secretion, emphasizing the applicability of non-canonical translation initiation across diverse species with broad implications for medical or industrial biotechnology.

The G932C mutation of chitin synthase 1 gene (CHS1) mediates buprofezin resistance as confirmed by CRISPR/Cas9-mediated knock-in approach in the brown planthopper, Nilaparvata lugens.

The brown planthopper (Nilaparvata lugens) is a major destructive rice pest in Asia. High levels of insecticide resistance have been frequently reported, and the G932C mutation in the chitin synthase 1 (CHS1) gene has been found to mediate buprofezin resistance. However, there has been no direct evidence to confirm the functional significance of the single G932C substitution mutation leading to buprofezin resistance in N. lugens. Here, we successfully constructed a knock-in homozygous strain (Nl-G932C) of N. lugens using CRISPR/Cas9 coupled with homology-directed repair (HDR). Compared with the background strain susceptible to buprofezin (Nl-SS), the knock-in strain (Nl-G932C) showed a 94.9-fold resistance to buprofezin. Furthermore, resistant strains (Nl-932C) isolated from the field exhibited a 2078.8-fold resistance to buprofezin, indicating that there are other mechanisms contributing to buprofezin resistance in the field. Inheritance analysis showed that the resistance trait is incomplete dominance. In addition, the Nl-G932C strain had a relative fitness of 0.33 with a substantially decreased survival rate, emergence rate, and fecundity. This study provided in vivo functional evidence for the causality of G932C substitution mutation of CHS1 with buprofezin resistance and valuable information for facilitating the development of resistance management strategies in N. lugens. This is the first example of using CRISPR/Cas9 gene-editing technology in a hemipteran insect to directly confirm the role of a candidate target site mutation in insecticide resistance.

Heat-shock protein 90α protects NME1 against degradation and suppresses metastasis of breast cancer.

BACKGROUND: NME1 has been exploited as a potential translational target for decades. Substantial efforts have been made to upregulate the expression of NME1 and restore its anti-metastasis function in metastatic cancer. METHODS: Cycloheximide (CHX) chase assay was used to measure the steady-state protein stability of NME1 and HSP90α. The NME1-associating proteins were identified by immunoprecipitation combined with mass spectrometric analysis. Gene knockdown and overexpression were employed to examine the impact of HSP90AA1 on intracellular NME1 degradation. The motility and invasiveness of breast cancer cells were examined in vitro using wound healing and transwell invasion assays. The orthotopic spontaneous metastasis and intra-venous experimental metastasis assays were used to test the formation of metastasis in vivo, respectively. RESULTS: HSP90α interacts with NME1 and increases NME1 lifetime by impeding its ubiquitin-proteasome-mediated degradation. HSP90α overexpression significantly inhibits the metastatic potential of breast cancer cells in vitro and in vivo. A novel cell-permeable peptide, OPT22 successfully mimics the HSP90α function and prolongs the life span of endogenous NME1, resulting in reduced metastasis of breast cancer. CONCLUSION: These results not only reveal a new mechanism of NME1 degradation but also pave the way for the development of new and effective approaches to metastatic cancer therapy.

Oncoprotein SET dynamically regulates cellular stress response through nucleocytoplasmic transport in breast cancer.

SETß is the predominant isoform of oncoprotein SE translocation (SET) in various breast cancer cell lines. Interactome-transcriptome analysis has shown that SETß is intimately associated with cellular stress response. Among various exogenous stimuli, formaldehyde (FA) causes distinct biological effects in a dose-dependent manner. In response to FA at different concentrations, SET dynamically shuttles between the nucleus and cytoplasm, performing diverse biofunctions to restore homeostasis. At a low concentration, FA acts as an epidermal growth factor (EGF) and activates the HER2 receptor and downstream signaling pathways in HER2+ breast cancer cells, resulting in enhanced cell proliferation. Nucleocytoplasmic transport of SETß is controlled by the PI3K/PKCα/CK2α axis and depletion or blockade of the transport of SETß suppresses EGF-induced activation of AKT and ERK. SETß also inhibits not only stress-induced activation of p38 MAPK signaling pathway, but also assembly of stress granules by hindering formation of the G3BP1-RNA complex. Our findings suggest that SET functions as an important regulator which modulates cellular stress signaling pathways dynamically.

Bisphenol F suppresses insulin-stimulated glucose metabolism in adipocytes by inhibiting IRS-1/PI3K/AKT pathway.

Obesity is one of the risk factors of metabolic diseases. Decreased sensitivity to insulin or impairment of the insulin signaling pathway may affect the metabolism of adipose tissue. Bisphenol F (BPF) has been widely used in various products as a substitute for bisphenol A (BPA). BPA has been defined as "obesogen". However, knowledge about the correlation between BPF and obesity is very limited. This study was aimed to explore the effects of BPF on glucose metabolism and insulin sensitivity in mammalian tissues, using a mouse 3T3-L1 adipocyte line as the model. Differentiated 3T3-L1 adipocytes were treated with BPF at various concentrations for 24 h or 48 h, followed by the measurement of cell viability, lipid accumulation, expression levels of adipocytokines, glucose consumption, and impairment of the insulin signaling pathway. The results indicated that BPF had no effect on the size of 3T3-L1 adipocytes, but the expression of leptin, adiponectin and apelin was decreased, while that of chemerin and resistin was increased after 48 h of BPF treatment. Moreover, BPF inhibited the glucose consumption, the expression of GLUT4, and its translocation to the plasma membranes in 3T3-L1 adipocytes. Western blot analysis indicated that the activation of IRS-1/PI3K/AKT signaling pathway was inhibited by BPF, which resulted in reduced GLUT4 translocation. In conclusion, our data suggest that exposure of adipocytes to BPF may alter the expression of calorie metabolism-related adipokines and suppress insulin-stimulated glucose metabolism by impairing the insulin signaling (IRS-1/PI3K/AKT) pathway.

Comparison of Functional and Radiographic Outcomes Between Two Fixation Methods for Extended Trochanteric Osteotomy in Revision Total Hip Arthroplasty: A Retrospective Cohort Study.

BACKGROUND: To compare the functional and radiographic outcomes between two fixation methods for extended trochanteric osteotomy (ETO) in revision total hip arthroplasty (rTHA). METHODS: Included in this study were 64 patients who underwent ETO in rTHA using either claw-plate fixation (claw-plate group, n = 31) or cable-alone fixation (cable group, n = 33) in our hospital from 2008 to 2020. The functional and radiographic results and complications were compared between the groups during a mean follow-up period of 64 and 78 months. RESULTS: The Harris hip score and visual analogue scale at the last follow-up improved significantly in both groups, showing no significant statistical difference between the two fixation methods. In the cable group, the mean abductor lever arm, the proximal migration, and medial migration in the affected hip were significantly decreased compared to those in the contralateral normal hip (P < .05), whereas in the claw-plate group no significant statistical differences were observed between two sides. No or slight limping occurred in 25 patients (81%) in the claw-plate group and 16 patients (48%) in the cable group (P = .007). A multiple logistic regression demonstrated that claw-plate fixation could reduce the incidence of postoperative moderate-to-severe limping. CONCLUSION: Both claw-plate fixation and cable-alone fixation could improve the functional performance of rTHA with ETO, whereas claw-plate fixation could offer superior biomechanical results and gait improvement as compared with cable-alone fixation.

Indoor MIMO-VLC Using Angle Diversity Transmitters.

In this paper, we, for the first time, apply angle diversity transmitters (ADTs) to enhance the performance of multiple-input multiple-output visible light communication (MIMO-VLC) systems. The ADT is designed to consist of one center light emitting diode (LED) and multiple inclined side LEDs. We calculate the line-of-sight (LOS) channel gain of the MIMO-VLC system using ADTs and further derive the average achievable rate of the system. We show that the average achievable rate is related to both the inclination angle of the side LEDs and the spacing between two adjacent ADTs in the MIMO-VLC system. Simulations are conducted to verify that the average achievable rate of the ADT-enhanced MIMO-VLC system can be maximized by setting the optimal inclination angle of the side LEDs and the optimal spacing between adjacent ADTs. The obtained results further show that the average achievable rate of the ADT-enhanced MIMO-VLC system can be greatly improved when there are more LEDs in each ADT. Specifically, a substantial 42.9% average achievable rate improvement can be achieved by using the optimized ADT in comparison to using a conventional non-angle diversity transmitter.

The application of custom-made 3D-printed titanium augments designed through surgical simulation for severe bone defects in complex revision total hip arthroplasty.

BACKGROUND: With the development of radiology and three-dimensional (3D) printing technology, custom-made 3D-printed titanium augments have been more widely used. However, the radiological and clinical outcomes of custom-made augments lack reports. To better understand the clinical effect of using 3D-printed titanium augments and the significance of accurate placement, the aim of this study was to assess the outcomes when using custom-made 3D-printed titanium augments and to validate the idea that surgical simulation should be done before designing custom-made augments. METHODS: A retrospective review was conducted on 31 surgical simulations and revision total hip arthroplasties using custom-made 3D-printed titanium augments. The safe zone, cup position, and hip rotation center were measured on anteroposterior radiographs. Clinical outcomes were assessed with a mean 21.1 months of follow-up. RESULTS: All patients were positioned within the safe zone, and none of the acetabular cups nor the custom-made augments had any evidence of migration at the latest follow-up. A strong correlation was found between the planned cup position and the postoperative position. The average vertical position of the center of rotation was significantly increased from 3.55 cm to 2.35 cm. The mean Harris Hip Score was increased from 40.81 preoperatively to 65.46 postoperatively. Complications included gait abnormality, groin pain, fracture of the greater trochanter, and partial palsy of the sciatic nerve. However, patient satisfaction reached 92.3%. CONCLUSION: Surgical simulations help to design custom-made augments accurately and improve surgical plans. Acetabular components supported with custom-made 3D-printed augments is a useful method to bridge severe bone deficiencies. In this study, both the radiologic results and clinical outcomes were favorable. LEVEL OF EVIDENCE: Level 4.

Metabolic engineering of Corynebacterium glutamicum WM001 to improve l-isoleucine production.

In this study, l-isoleucine production in Corynebacterium glutamicum WM001 was improved by deleting three genes in the genome, replacing the native promoter of ilvA in the genome, and overexpression of five genes in an alr-based auxotrophic complementation expression system. The three genes deleted in the genome are alaT, brnQ, and alr. Deletion of alaT improved l-isoleucine production by increasing the supply of pyruvate, whereas deletion of brnQ improved l-isoleucine production by blocking the uptake of extracellular l-isoleucine. Exchange of the native promoter of ilvA with promoter tac or tacM could contribute to l-isoleucine production by increasing 2-ketobutyric acid; tac is better than tacM for improving l-isoleucine yield. Different combinations of the genes ilvBN, ppnK, lrp, and brnFE were overexpressed in an alr-based auxotrophic complementation expression system to further improve l-isoleucine production, and the best yield after 72-H flask fermentation was obtained from the strain WM005/pYCW-1-ilvBN2-ppnK1. Without addition of any antibiotics, WM005/pYCW-1-ilvBN2-ppnK1 could produce 32.1 g/L l-isoleucine after 72-H fed-batch fermentation, which is 34.3% increase compared with the original strain WM001.

Complete Genome of Marine Microalgae Associated Algicidal Bacterium Sulfitobacter pseudonitzschiae H46 with Quorum Sensing System.

Sulfitobacter pseudonitzschiae H46, a marine bacterium associated with microalgae, exhibits algicidal activity against harmful algal bloom microalgae Chattonella marina and Alexandrium tamarense. The complete genome of S. pseudonitzschiae H46 was sequenced to investigate its algicidal mechanism further. One chromosome, eight circular plasmids and add one not circularized plasmid (Plas II) were identified, which are 4.93 Mb in length with 4871 open reading frames. The genome contains 43 transfer RNA (tRNA) genes; six ribosome RNA (rRNA) genes that can be classified into two 5S rRNA, two 16S rRNA, two 23S rRNA, and two small RNA (sRNA) genes. Genomic annotation revealed that S. pseudonitzschiae H46 has two pairs of LuxI/R-type Quorum-sensing (QS) systems. The QS systems can regulate the functions involved in host colonization and biofilm formation. Moreover, the existence of 49 Type-IV and Dddl genes in the chromosome indicated that Dimethylsulfoniopropionate (DMSP) catabolism of S. pseudonitzschiae H46 is the main interaction with marine microalgae. S. pseudonitzschiae H46 utilizes DMSP produced by microalgae as the carbon source, and this may induce algicidal activity. The complete genome sequence of S. pseudonitzschiae H46 can provide useful information on the underlying molecular mechanism between QS and algicidal activity.

Heat stress and cow factors affect bacteria shedding pattern from naturally infected mammary gland quarters in dairy cattle.

Mastitis-causing pathogens are shed from infected mammary gland quarters and thus contribute to an increased risk of new intramammary infections. The objective of the current study was to investigate the shedding characteristics of various mastitis-causing pathogens and associated animal-specific (somatic cell score and parity) and environmental (heat stress) factors. In a longitudinal study, infected udder quarters were sampled consecutively on 5 dairy farms in Germany. To capture climatic factors, temperature-humidity index (THI) was calculated. In the laboratory analysis, the pathogens and their counts in the milk samples were determined. A generalized linear mixed model with gamma link was used to evaluate the factors influencing pathogen-shedding characteristics. The variables somatic cell count, pathogen, parity, and THI had significant influence on pathogen shedding. Staphylococci were shed in lower values than streptococci. The pathogen shedding from mammary gland quarters with intramammary infections was higher in the first and second lactation than in higher lactations. Exceeding the THI threshold 60 resulted in higher pathogen counts on the same day. This was only caused by the pathogens yeasts and Streptococcus uberis. Possible mechanisms causing differences in pathogen shedding are changes in the counts due to influenced milk quantities, better growth conditions at higher temperatures, or altered immunological reactions. The mechanisms often remain speculative and require further investigation. The study underlines the contribution of cows with high somatic cell counts regarding the transmission of mastitis pathogens within a herd. Furthermore, it becomes clear that heat stress in Germany influences udder health and that prevention measures are useful.

Factors influencing knee valgus alignment in Crowe type IV hip dysplasia after total hip arthroplasty.

BACKGROUND: Valgus deformity of the knee remains a complaint after total hip arthroplasty (THA) among some patients with Crowe type IV hip dysplasia. We aimed to identify the knee alignment in these patients before and after surgery, and to explore the factors contributing to postoperative knee valgus alignment. MATERIALS AND METHODS: We retrospectively reviewed a series of Crowe type IV patients who received THA between February 2010 and May 2019 in our hospital. The patients' medical data were collected from the hospital information system. On both preoperative and postoperative full limb length standing radiographs, the following parameters were measured: hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle, anatomical tibiofemoral angle, anatomical lateral distal femoral angle, femoral neck-shaft angle, pelvic obliquity, limb length, height and lateral distance of hip center, and femoral offset. Univariate and multivariate binary logistic regression were used to identify the factors influencing postoperative knee valgus alignment. RESULTS: A total of 64 Crowe type IV patients (87 hips) were included in the study. Overall, HKA improved from 176.54 ± 3.52° preoperatively to 179.45 ± 4.31° at the last follow-up. Those hips were subdivided into non-valgus group (≥ 177.0°, n = 65) and valgus group (< 177.0°, n = 22) according to postoperative HKA. Only postoperative mLDFA was a significant factor in the multivariate regression model. CONCLUSIONS: The postoperative mLDFA is a major factor related to knee valgus alignment after THA, which combines the preoperative anatomy and surgical reconstruction. Other factors previously published were found to have no significance. LEVEL OF EVIDENCE: III.

Comparison of phenotypic and genotypic antimicrobial resistance patterns associated with Staphylococcus aureus mastitis in German and Danish dairy cows.

Staphylococcus aureus is one of the most common pathogens associated with bovine mastitis in Germany and Denmark. Successful therapy is strongly linked to the susceptibility of the pathogen to the administered antimicrobial. An increase in resistant pathogens in human and veterinary medicine has become a concern worldwide and hampers therapy due to reduced susceptibility. In the present study, susceptibility testing was performed for 85 and 93 S. aureus isolates originating from mastitis cases on 12 German and 8 Danish dairy farms, respectively. Phenotypic examination was performed by detection of minimal inhibitory concentration (MIC) values using the broth microdilution method, followed by genotypic investigations of the blaZ and mecA resistance genes via PCR. The tested antimicrobials were the most frequently used ß-lactams in German and Danish dairy farms, including cefquinome, cefoperazone, cephapirin, penicillin, oxacillin, cloxacillin, amoxicillin-clavulanic acid, and cephalexin-kanamycin. Special attention was paid to varying therapy concepts because, in Germany, third- and fourth-generation cephalosporins have been predominantly used in mastitis therapy, whereas in Denmark, restrictive use of penicillin is followed by a general avoidance of cephalosporins. Differences in MIC values were mainly based on determined MIC90 values (MIC at which 90% of isolates are inhibited). In general, Danish S. aureus isolates were inhibited at comparatively lower MIC90 values than S. aureus isolated from German dairy farms for most ß-lactams. No differences were observed regarding cefquinome, because both German and Danish isolates exhibited MIC50 and MIC90 values of 0.5 and 1 µg/mL, respectively. In contrast, the MIC90 for penicillin against German and Danish S. aureus were 0.5 and ≤0.06 µg/mL, respectively. Resistance genes (blaZ, mecA) were only detected in German S. aureus isolates on 3 dairy farms in Germany. A total of 5 isolates tested positive for both blaZ and mecA, whereas 1 isolate carried the blaZ resistance gene only. A direct correlation between frequently used antimicrobials and reduced susceptibility could not be determined based on results of the present study. In addition to further research to determine factors associated with resistance development, we emphasize the urgent need for internationally standardized clinical breakpoints to assess resistance situations more accurately.

Baseline determination, susceptibility monitoring and risk assessment to triflumezopyrim in Nilaparvata lugens (Stål).

Triflumezopyrim, a novel mesoionic chemical insecticide, is promoted as a powerful tool for control of susceptible and resistant hopper species in rice throughout Asia. For a newly commercialized insecticide it is important to establish susceptibility baseline, conduct susceptibility monitoring, and assess the risk of resistance via artificial selection to provide foundational information on designing resistance management strategy. The susceptibility baseline of triflumezopyrim was established for three rice planthopper species, Nilarpavata lugens (Stål), Sogatella furcifera (Horváth) and Laodelphax striatellus (Fallén). The LD50 of triflumezopyrim was 0.026, 0.032 and 0.094 ng/individual for the adults of the susceptible strains of S. furcifera, L. striatellus and N. lugens, respectively, determined by a topical application method. Using a rice stem (seedling) dipping method, the LC50 was determined as 0.042, 0.024 and 0.150 mg/L for the nymphs (3rd instar) of the three hopper species, respectively. In the meanwhile, the LC50 of Pyraxalt™ (triflumezopyrim 10% SC) was 0.064 mg/L for the N. lugens susceptible strain. Furthermore, the susceptibility of triflumezopyrim and other five neonicotinoid insecticides were monitored for N. lugens field populations collected from major rice production areas in China in 2015-2019. All monitored populations were susceptible to triflumezopyrim (0.5 to 3.9-fold resistance ratio), and showed no cross-resistance to the other five neonicotinoids. These results suggested that triflumezopyrim is a good option to control resistant N. lugens. In addition, a field-collected population of N. lugens was artificially selected with triflumezopyrim for 20 generations and resulted in 3.5-fold increase in LC50 from F0 and 6.0-fold increase from that of the susceptible strain. The realized heritability (h2) of resistance was estimated as 0.0451 by using threshold trait analysis. With this h2 value, the projected triflumezopyrim resistance development (a 10-fold increase in LC50) would be expected after 30.3 or 24.0 generations if 80% or 90% of the population was killed at each generation.

Pymetrozine inhibits reproductive behavior of brown planthopper Nilaparvata lugens and fruit fly Drosophila melanogaster.

Pymetrozine is a promising chemical used to control brown planthopper, which developed resistance to imidacloprid and buprofezin in the past decade. Field efficacy indicates that pymetrozine can reduce the number of offsprings of brown planthopper, but the specific physiological mechanism is unknown. In this study, we systematically described the mating process of brown planthopper including 8 steps (abdominal vibration, following, positioning, wing extension, attempted copulation, copulation, terminated copulation and leaving) and explored the optimal mating time after adult eclosion (3-5 days) and observation time (30 mins). Also, behavioral data showed that pymetrozine can affect the mating behavior and female fecundity of brown planthopper and fruit fly. As one of the target genes for pymetrozine, Nanchung (Nan), the nan36a mutant male courtship index, female receptivity and the number of offsprings were significantly decreased. Behavioral defects in nan36a mutant flies can be rescued by expressed NlNan. Our results indicated that Nan plays essential roles in the mating behavior and female fecundity. These findings provide useful information for demonstrating that pymetrozine effectively reduce the reproduction of brown planthopper and contribute to our understanding of reproductive strategies controlled by pymetrozine in insects.

Development of a Near Ground Remote Sensing System.

Unmanned Aerial Vehicles (UAVs) have shown great potential in agriculture and are increasingly being developed for agricultural use. There are still a lot of experiments that need to be done to improve their performance and explore new uses, but experiments using UAVs are limited by many conditions like weather and location and the time it takes to prepare for a flight. To promote UAV remote sensing, a near ground remote sensing platform was developed. This platform consists of three major parts: (1) mechanical structures like a horizontal rail, vertical cylinder, and three axes gimbal; (2) power supply and control parts; (3) onboard application components. This platform covers five degrees of freedom (DOFs): horizontal, vertical, pitch, roll, yaw. A stm32 ARM single chip was used as the controller of the whole platform and another stm32 MCU was used to stabilize the gimbal. The gimbal stabilizer communicates with the main controller via a CAN bus. A multispectral camera was mounted on the gimbal. Software written in C++ language was developed as the graphical user interface. Operating parameters were set via this software and the working status was displayed in this software. To test how well the system works, a laser distance meter was used to measure the slide rail's repeat accuracy. A 3-axis vibration analyzer was used to test the system stability. Test results show that the horizontal repeat accuracy was less than 2 mm; vertical repeat accuracy was less than 1 mm; vibration was less than 2 g and remained at an acceptable level. This system has high accuracy and stability and can therefore be used for various near ground remote sensing studies.

[Nonlinear Regression Methods of Ethanol Raman Spectra Quantitative Analysis].

Ethanol concentration quantitative analysis of ethanol-water solution can be realized by measuring the ratio of Raman characteristic peak heights. The content of ethanol can be determined by linear relation between relative intensity ratio and ethanol concentration. However, this analytical method only applies to the ethanol solution at low concentration. Concerning this issue, relative intensity of characteristic peak of ethanol (asymmetric stretching vibration of CH2 2 924.0 cm-1) and peak background of water (3 350 cm-1) at different ethanol concentration is experimentally measured by using a self-developed laser Raman ethanol content detection system. According to the relationship between relative ratio of characteristic peak heights and ethanol concentration, the nonlinear regression analysis methods are proposed to apply in the measurement of ethanol concentration in a wide range. Adjacent region average method is utilized to remove mutational random noise in Raman spectra of ethanol solution. Combined with multi-point interpolation processing, the baseline of Raman spectra can be calibrated. The influences of mutational random noise and the strong fluorescence background can be effectively eliminated with baseline correction and normalization methods. Polynomial and exponential mathematical models are adopted for nonlinear regression analyses by the relation between ratio of characteristic peak heights and concentration of ethanol solution. The analysis results show that the correlation coefficient of linear fitting and nonlinear fitting is about 0.991 and higher than 0.997 respectively. The linear analytical method can be effectively applied when ethanol concentration range is 15%～60%. The nonlinear analytical method has higher measurement accuracy in a wider ethanol concentration range of 3%～97%. Nonlinear mathematical model will provide theoretical basis for analysis of ethanol concentration, which can be applied in laser Raman ethanol content detection system to calculate the relatively accurate ethanol concentration of ethanol-water solution. Rapid, real-time and accurate quantitative analysis of wide concentration range ethanol solution, which has mutational random noise and strong fluorescence background interference, can be achieved by these analytical methods.

Theoretical and experimental investigations on measuring underwater temperature by the coherent Brillouin scattering method.

In this paper, a new method of measuring a water-stimulated Brillouin scattering (SBS) frequency shift by optical coherent detection is presented, in order to remote-sense the underwater temperature of the ocean. A single longitudinal mode, passively Q-switched pulsed Nd:YAG laser is used as the light source, the water SBS beam is used as the signal beam, and a portion of the incident laser beam is used as the local oscillator. The heterodyne is detected by a high-speed photodetector, and the heterodyne frequency is the Brillouin frequency shift. Therefore, the underwater temperature can be determined according to the relationship between the Brillouin frequency shift and the water temperature. To test and verify its practicability, the heterodyne waveforms at different water temperatures are recorded in the laboratory with a wide-band oscilloscope, and the Brillouin frequency shifts are deduced by a Fourier transform. The experimental results are consistent with the theoretical analysis. This work provides the foundation for the development of a water temperature measurement system based on coherent Brillouin scattering.

Quantitative analysis of mitral valve morphology in mitral valve prolapse with real-time 3-dimensional echocardiography: importance of annular saddle shape in the pathogenesis of mitral regurgitation.

BACKGROUND: Few data exist on the relation of the 3-dimensional morphology of mitral valve and degree of mitral regurgitation (MR) in mitral valve prolapse. METHODS AND RESULTS: Real-time 3-dimensional transesophageal echocardiography of the mitral valve was acquired in 112 subjects, including 36 patients with mitral valve prolapse and significant MR (≥3+; MR+ group), 32 patients with mitral valve prolapse but no or mild MR (≤2+; MR- group), 12 patients with significant MR resulting from nonprolapse pathologies (nonprolapse group), and 32 control subjects. The 3-dimensional geometry of mitral valve apparatus was measured with dedicated quantification software. Compared with the normal and MR- groups, the MR+ group had more dilated mitral annulus (P<0.0001), a reduced annular height to commissural width ratio (AHCWR) (P<0.0001) indicating flattening of annular saddle shape, redundant leaflet surfaces (P<0.0001), greater leaflet billow volume (P<0.0001) and billow height (P<0.0001), longer lengths from papillary muscles to coaptation (P<0.0001), and more frequent chordal rupture (P<0.0001). Prevalence of chordal rupture increased progressively with annulus flattening (7% versus 24% versus 42% for AHCWR >20%, 15%-20%, and <15%, respectively; P=0.004). Leaflet billow volume increased exponentially with decreasing AHCWR in patients without chordal rupture (r(2)=0.66, P<0.0001). MR severity correlated strongly with leaflet billow volume (r(2)=0.74, P<0.0001) and inversely with AHCWR (r(2)=0.44, P<0.0001). In contrast, annulus dilatation but not flattening occurred in nonprolapse MR patients. An AHCWR <15% (odds ratio=7.1; P=0.0004) was strongly associated with significant MR in mitral valve prolapse. CONCLUSION: Flattening of the annular saddle shape is associated with progressive leaflet billowing and increased frequencies of chordal rupture and may be important in the pathogenesis of MR in mitral valve prolapse.

Vibration sensor-based bearing fault diagnosis using ellipsoid-ARTMAP and differential evolution algorithms.

Effective fault classification of rolling element bearings provides an important basis for ensuring safe operation of rotating machinery. In this paper, a novel vibration sensor-based fault diagnosis method using an Ellipsoid-ARTMAP network (EAM) and a differential evolution (DE) algorithm is proposed. The original features are firstly extracted from vibration signals based on wavelet packet decomposition. Then, a minimum-redundancy maximum-relevancy algorithm is introduced to select the most prominent features so as to decrease feature dimensions. Finally, a DE-based EAM (DE-EAM) classifier is constructed to realize the fault diagnosis. The major characteristic of EAM is that the sample distribution of each category is realized by using a hyper-ellipsoid node and smoothing operation algorithm. Therefore, it can depict the decision boundary of disperse samples accurately and effectively avoid over-fitting phenomena. To optimize EAM network parameters, the DE algorithm is presented and two objectives, including both classification accuracy and nodes number, are simultaneously introduced as the fitness functions. Meanwhile, an exponential criterion is proposed to realize final selection of the optimal parameters. To prove the effectiveness of the proposed method, the vibration signals of four types of rolling element bearings under different loads were collected. Moreover, to improve the robustness of the classifier evaluation, a two-fold cross validation scheme is adopted and the order of feature samples is randomly arranged ten times within each fold. The results show that DE-EAM classifier can recognize the fault categories of the rolling element bearings reliably and accurately.