Enhanced properties of the mid-infrared superluminescent emitter with a composite waveguide.

This study reports on a composite structure composing tilted taper, and tilted and curved waveguides with the aim of enhancing the spectral width and output power of mid-infrared quantum cascade superluminescent emitters (QC-SLEs). The computational results indicate that a tilt angle of 10° and a curved angle of 20° can avoid the selectivity of a certain wavelength due to interference effects at tilt angles of 6° and 8°, resulting in the minimum reflectivity of 1.3×10-4 and 4.4×10-4 for each wide and narrow cavity surface. Simultaneously, the modes propagating perpendicular to the cavity surface exist the least. The corresponding experimental results show a significant enhancement in the spectral width to 168.5c m -1 and a high power output of 5.1 mW for the device. This study presents what we believe to be a novel concept for the designing of superluminescent emitters with both a broadband and high power output.

Identification of sources and analysis of spatial distribution of soil heavy metals in northern China coal mining areas.

The mining and utilization of coal resources has not only promoted rapid economic development but also poses a potential threat to the ecological environment. The purpose of this study is to clarify the effects both of mining and land use types on the spatial distribution and particular sources of heavy metals in soil, using inverse distance weighted (IDW) and the Positive Matrix Factorization (PMF) model. A total of 99 topsoil and profile soil samples across different land use types and mining conditions were collected. The contamination of soil with Cd, Pb, and Hg in the research area was most severe, with the coefficient of variation (CV) of Hg being the largest, while also being heavily influenced by human activities. Severely polluted regions were mainly distributed in the center of the coal mining area, as well as near the highway. The contents of heavy metals for various land use patterns were ranked as follows: forestland > farmland > bare land > grassland > building land. Hg, Cd, Pb, Cr, and Zn had showed migration in the 0-60 cm depth range, and the enrichment factors (EFs) of Cd, Pb, Hg, and As in the soil profile were the most significant. The PMF demonstrated that the contributions of industrial activities and atmospheric deposition, transportation and mining activities, agricultural activities, and natural sources accounted for 31.25%, 28.13%, 22.24%, and 18.38%, respectively. The migration and deposition of atmospheric particulate matter from coal mining, transportation, and coal combustion under winds triggered heavy metal contamination in semi-arid areas of northern China. This phenomenon has important implications for the prevention and reduction of heavy metal pollution through various effective measures in coal-mining cities in northern China.

4D LUT: Learnable Context-Aware 4D Lookup Table for Image Enhancement.

Image enhancement aims at improving the aesthetic visual quality of photos by retouching the color and tone, and is an essential technology for professional digital photography. Recent years deep learning-based image enhancement algorithms have achieved promising performance and attracted increasing popularity. However, typical efforts attempt to construct a uniform enhancer for all pixels' color transformation. It ignores the pixel differences between different content (e.g., sky, ocean, etc.) that are significant for photographs, causing unsatisfactory results. In this paper, we propose a novel learnable context-aware 4-dimensional lookup table (4D LUT), which achieves content-dependent enhancement of different contents in each image via adaptively learning of photo context. In particular, we first introduce a lightweight context encoder and a parameter encoder to learn a context map for the pixel-level category and a group of image-adaptive coefficients, respectively. Then, the context-aware 4D LUT is generated by integrating multiple basis 4D LUTs via the coefficients. Finally, the enhanced image can be obtained by feeding the source image and context map into fused context-aware 4D LUT via quadrilinear interpolation. Compared with traditional 3D LUT, i.e., RGB mapping to RGB, which is usually used in camera imaging pipeline systems or tools, 4D LUT, i.e., RGBC(RGB+Context) mapping to RGB, enables finer control of color transformations for pixels with different content in each image, even though they have the same RGB values. Experimental results demonstrate that our method outperforms other state-of-the-art methods in widely-used benchmarks.

TTVFI: Learning Trajectory-Aware Transformer for Video Frame Interpolation.

Video frame interpolation (VFI) aims to synthesize an intermediate frame between two consecutive frames. State-of-the-art approaches usually adopt a two-step solution, which includes 1) generating locally-warped pixels by calculating the optical flow based on pre-defined motion patterns (e.g., uniform motion, symmetric motion), 2) blending the warped pixels to form a full frame through deep neural synthesis networks. However, for various complicated motions (e.g., non-uniform motion, turn around), such improper assumptions about pre-defined motion patterns introduce the inconsistent warping from the two consecutive frames. This leads to the warped features for new frames are usually not aligned, yielding distortion and blur, especially when large and complex motions occur. To solve this issue, in this paper we propose a novel Trajectory-aware Transformer for Video Frame Interpolation (TTVFI). In particular, we formulate the warped features with inconsistent motions as query tokens, and formulate relevant regions in a motion trajectory from two original consecutive frames into keys and values. Self-attention is learned on relevant tokens along the trajectory to blend the pristine features into intermediate frames through end-to-end training. Experimental results demonstrate that our method outperforms other state-of-the-art methods in four widely-used VFI benchmarks. Both code and pre-trained models will be released at https://github.com/ChengxuLiu/TTVFI.

Periodicity measure of cyclo-stationary impulses based on low sparsity of Gini index and its application to bearing diagnosis.

A key problem in the fault diagnosis of rolling element bearings is the extraction of features of repetitive transients from vibration signals. The accurate evaluation of maximizing spectral sparsity under complex interference conditions for measuring the periodicity of transients is typically difficult to implement. Accordingly, a novel periodicity measurement approach was designed for time waveforms. According to the Robin Hood criteria, the Gini index of a sinusoidal signal has a stable low sparsity. The periodic modulation of cyclo-stationary impulses can be represented by several sinusoidal harmonics based on envelope autocorrelation and bandpass filtering. Thus, this low sparsity of Gini index can be used to evaluate the periodic strength of modulation components. Finally, a sequential feature evaluation method is developed to extract periodic impulses accurately. The proposed method is tested on simulation and bearing fault datasets and compared with the state-of-art methods so to assess its effectiveness.

Bearing fault diagnosis based on singular value distribution of impulse response segment.

Extracting periodic impact features from vibration signals has always been a key issue in the fault diagnosis of rolling element bearings. However, the repetitive impacts induced by localized defects are difficult to identify due to the presence of background noise and interferences. A novel approach for bearing fault diagnosis based on singular value distribution of impulse response segment is proposed. The characteristics of singular value decomposition (SVD) of the impulse response are analyzed, and the relationship between the matrix row number and the bandwidth of subspace is estimated quantitatively. According to the unique distribution of singular values, the double-order attenuation ratio (DAR) is designed to evaluate the transient component of the short-time segment. Then, by segmenting the vibration signal, the time-dependent DAR sequences are obtained, which can be used to locate the impacts in the signal. Eventually, the fault-related cyclo-stationarity in DAR sequences is enhanced by autocorrelation and measured by the Gini index. The effectiveness of the proposed method is verified by simulation and bearing fault datasets, in contrast to the state-of-art algorithms.

Product Recognition for Unmanned Vending Machines.

Recently, the emerging concept of "unmanned retail" has drawn more and more attention, and the unmanned retail based on the intelligent unmanned vending machines (UVMs) scene has great market demand. However, existing product recognition methods for intelligent UVMs cannot adapt to large-scale categories and have insufficient accuracy. In this article, we propose a method for large-scale categories product recognition based on intelligent UVMs. It can be divided into two parts: 1) first, we explore the similarities and differences between products through manifold learning, and then we build a hierarchical multigranularity label to constrain the learning of representation; and 2) second, we propose a hierarchical label object detection network, which mainly includes coarse-to-fine refine module (C2FRM) and multiple granularity hierarchical loss (MGHL), which are used to assist in capturing multigranularity features. The highlights of our method are mine potential similarity between large-scale category products and optimization through hierarchical multigranularity labels. Besides, we collected a large-scale product recognition dataset GOODS-85 based on the actual UVMs scenario. Experimental results and analysis demonstrate the effectiveness of the proposed product recognition methods.

Occurrence and antimicrobial susceptibility of Porphyromonas spp. and Fusobacterium spp. in dogs with and without periodontitis.

The occurrence of Porphyromonas gulae, Porphyromonas macacae, Fusobacterium nucleatum and Fusobacterium canifelinum in subgingival plaque from dogs with and without periodontitis as well as their antimicrobial susceptibility were evaluated. From 50 dogs with periodontitis were identified 38 P. gulae, 8 P. macacae, 26 F. nucleatum and 15 F. canifelinum, and from 50 dogs without periodontitis were identified 15 P. gulae, 12 F. nucleatum and 11 F. canifelinum. All strains were susceptible to most of the antibiotics tested, however, different resistance rates to clarithromycin, erythromycin and metronidazole among strains were observed. The role of P. gulae, P. macacae, F. nucleatum and F. canifelinum in periodontal disease of household pets needs to be defined to a better prevention and treatment of the canine periodontitis.

Detection of Porphyromonas gulae from subgingival biofilms of dogs with and without periodontitis.

A rapid PCR approach was developed to detect Porphyromonas gulae strains from subgingival samples of dogs with and with periodontitis. The presence of P. gulae was observed in 92% and 56%, respectively, in dogs with and without periodontitis. The new primer pair was specific to detect this microorganism, and this technique could be used to evaluate a correlation between periodontitis and P. gulae in companion animals.

Application of quantitative real-time PCR for rapid identification of Bacteroides fragilis group and related organisms in human wound samples.

Our goal was to establish a quantitative real-time PCR (QRT-PCR) method to detect Bacteroides fragilis group and related organisms from clinical specimens. Compared to conventional anaerobic culture, QRT-PCR can provide accurate and more rapid detection and identification of B. fragilis group and similar species. B. fragilis group and related organisms are the most frequently isolated anaerobic pathogens from clinical samples. However, culture and phenotypic identification is quite time-consuming. We designed specific primers and probes based on the 16S rRNA gene sequences of Bacteroides caccae, Bacteroides eggerthii, B. fragilis, Bacteroides ovatus, Bacteroides stercoris, Bacteroides thetaiotaomicron, Bacteroides uniformis, Bacteroides vulgatus, Odoribacter splanchnicus (Bacteroides splanchnicus), Parabacteroides distasonis (Bacteroides distasonis) and Parabacteroides merdae (Bacteroides merdae), and detected these species by means of QRT-PCR in 400 human surgical wound infection samples or closed abscesses. The target bacteria were detected from 31 samples (8%) by culture, but from 132 samples (33%) by QRT-PCR (p-value < 0.001). B. uniformis was the most common species (44 positive samples) according to QRT-PCR while culture showed it to be B. fragilis (16 positive samples). Additionally, for each species QRT-PCR detected higher counts than culture did; this may reflect detecting DNA of dead organisms by QRT-PCR. QRT-PCR is a rapid and sensitive method which has great potential for detection of B. fragilis group and related organisms in wound samples.

Lab-on-a-chip for the isolation and characterization of circulating tumor cells.

A smart miniaturized system is being proposed for the isolation and characterization of circulating tumor cells (CTCs) directly from blood. Different microfluidic modules have been designed for cell enrichment and -counting, multiplex mRNA amplification as well as DNA detection. With the different modules at hand, future effort will focus on the integration of the modules in a fully automated, single platform.

Pyrosequencing study of fecal microflora of autistic and control children.

There is evidence of genetic predisposition to autism, but the percent of autistic subjects with this background is unknown. It is clear that other factors, such as environmental influences, may play a role in this disease. In the present study, we have examined the fecal microbial flora of 33 subjects with various severities of autism with gastrointestinal symptoms, 7 siblings not showing autistic symptoms (sibling controls) and eight non-sibling control subjects, using the bacterial tag encoded FLX amplicon pyrosequencing (bTEFAP) procedure. The results provide us with information on the microflora of stools of young children and a compelling picture of unique fecal microflora of children with autism with gastrointestinal symptomatology. Differences based upon maximum observed and maximum predicted operational taxonomic units were statistically significant when comparing autistic and control subjects with p-values ranging from <0.001 to 0.009 using both parametric and non-parametric estimators. At the phylum level, Bacteroidetes and Firmicutes showed the most difference between groups of varying severities of autism. Bacteroidetes was found at high levels in the severely autistic group, while Firmicutes were more predominant in the control group. Smaller, but significant, differences also occurred in the Actinobacterium and Proteobacterium phyla. Desulfovibrio species and Bacteroides vulgatus are present in significantly higher numbers in stools of severely autistic children than in controls. If the unique microbial flora is found to be a causative or consequent factor in this type of autism, it may have implications with regard to a specific diagnostic test, its epidemiology, and for treatment and prevention.

Characterization of Slackia exigua isolated from human wound infections, including abscesses of intestinal origin.

Eleven clinical strains isolated from infected wound specimens were subjected to polyphasic taxonomic analysis. Sequence analysis of the 16S rRNA gene showed that all 11 strains were phylogenetically related to Slackia exigua. Additionally, conventional and biochemical tests of 6 of the 11 strains were performed as supplementary methods to obtain phenotypic identification by comparison with the phenotypes of the relevant type strains. S. exigua has been considered an oral bacterial species in the family Coriobacteriaceae. This organism is fastidious and grows poorly, so it may easily be overlooked. The 16S rRNA gene sequences and the biochemical characteristics of four of the S. exigua strains isolated for this study from various infections indicative of an intestinal source were almost identical to those of the validated S. exigua type strain from an oral source and two of the S. exigua strains from oral sources evaluated in this study. Thus, we show for the first time that S. exigua species can be isolated from extraoral infections as well as from oral infections. The profiles of susceptibility to selected antimicrobials of this species were also investigated for the first time.

Corynebacterium pyruviciproducens sp. nov., a pyruvic acid producer.

A coryneform strain, 06-1773O(T) (=WAL 19168(T)), derived from a groin abscess sample was characterized using phenotypic and molecular taxonomic methods. Comparative analyses revealed more than 3 % divergence of the 16S rRNA gene sequence and about 10 % divergence of the partial rpoB gene sequence from the type strain of Corynebacterium glucuronolyticum. The strain could also be differentiated from C. glucuronolyticum by a set of phenotypic properties. A DNA-DNA relatedness study between strain WAL 19168(T) and C. glucuronolyticum CCUG 35055(T) showed a relatedness value of 13.3 % (13.7 % on repeat analysis). The genotypic and phenotypic data show that the strain merits classification within a novel species of Corynebacterium. We propose the name Corynebacterium pyruviciproducens sp. nov. for the novel species. The type strain is 06-1773O(T) (=WAL 19168(T) =CCUG 57046(T) =ATCC BAA-1742(T)).

Murdochiella asaccharolytica gen. nov., sp. nov., a Gram-stain-positive, anaerobic coccus isolated from human wound specimens.

Two strains of previously unknown Gram-stain-positive, anaerobic, coccus-shaped bacteria from human wound specimens were characterized using phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies and distinguishable biochemical characteristics demonstrated that these two unknown strains, WAL 1855C(T) and WAL 2038E, are genotypically homogeneous and constitute a novel lineage within Clostridium cluster XIII. There was 13-14 % 16S rRNA gene sequence divergence between the novel strains and the most closely related species, Parvimonas micra, Finegoldia magna and species of Helcococcus. Based on the phenotypic and phylogenetic findings, a novel genus and species, Murdochiella asaccharolytica gen. nov., sp. nov., are proposed. Strain WAL 1855C(T) (=ATCC BAA-1631(T) =CCUG 55976(T)) is the type strain of Murdochiella asaccharolytica.

Gemella asaccharolytica sp. nov., isolated from human clinical specimens.

Three strains of an unidentified Gram-stain-variable, fastidious, catalase-negative, capnophilic, non-spore-forming, coccus-shaped bacterium from human wound specimens were characterized by phenotypic and molecular taxonomic methods. Initially, these strains were anaerobic; with repeated culture, they became aerotolerant. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strains were genealogically homogeneous and constituted a novel subline within the genus Gemella. The unknown bacterium was readily distinguished from other Gemella species by biochemical tests. On the basis of both phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium from clinical specimens be classified as Gemella asaccharolytica sp. nov. The type strain is WAL 1945J(T) (=ATCC BAA-1630(T) =CCUG 57045(T)).

Reclassification of Clostridium coccoides, Ruminococcus hansenii, Ruminococcus hydrogenotrophicus, Ruminococcus luti, Ruminococcus productus and Ruminococcus schinkii as Blautia coccoides gen. nov., comb. nov., Blautia hansenii comb. nov., Blautia hydrogenotrophica comb. nov., Blautia luti comb. nov., Blautia producta comb. nov., Blautia schinkii comb. nov. and description of Blautia wexlerae sp. nov., isolated from human faeces.

Phenotypic and phylogenetic studies were performed on 15 isolates of an unidentified Gram-positive, anaerobic, non-sporulating coccobacillus-shaped bacterium isolated from human faeces. The novel organisms were catalase-negative, indole-negative and produced acetate and succinate as end products of metabolism. Comparative 16S rRNA gene sequencing demonstrated that the 15 isolates were highly related to each other and formed a hitherto unknown subline within the clostridial rRNA cluster XIVa. The novel isolates formed a robust phylogenetic group with a number of organisms which included Clostridium coccoides, Ruminococcus luti, Ruminococcus obeum and a number of other misclassified ruminococci. On the basis of these studies, a novel genus, Blautia gen. nov., is proposed. It is suggested that Clostridium coccoides, Ruminococcus hansenii, Ruminococcus hydrogenotrophicus, Ruminococcus luti, Ruminococcus productus, and Ruminococcus schinkii are transferred to this genus as Blautia coccoides gen. nov., comb. nov., Blautia hansenii comb. nov., Blautia hydrogenotrophica comb. nov., Blautia luti comb. nov., Blautia producta comb. nov. and Blautia schinkii comb. nov. One of the new isolates, the hitherto unknown coccus-shaped bacterial strain WAL 14507T (=ATCC BAA-1564T=DSM 19850T) is proposed as representing the type strain of a novel species, Blautia wexlerae sp. nov.

A new rat model links two contemporary theories in irritable bowel syndrome.

RATIONALE: Two proposed hypotheses for irritable bowel syndrome (IBS) are acute gastroenteritis and bacterial overgrowth. We studied whether acute infection with Campylobacter could precipitate bacterial overgrowth in a rat model in order to link the two hypotheses. METHODS: Sprague-Dawley outbred rats were randomly administered a vehicle or Campylobacter jejuni strain 81-176 by oral gavage. Three months after clearance of the infectious agent, rats had a stool consistency evaluation. After euthanasia, lumenal bacteria counts were measured via quantitative real-time PCR from self-contained segments of the duodenum, jejunum, ileum, cecum and left colon. Adjacent sections of bowel were fixed in formalin for evaluation of intraepithelial lymphocyte counts. RESULTS: Three months after clearance of Campylobacter infection, 57% of Campylobacter infected rats had some alteration in stool consistency compared to 7.4% in mock-infected controls (P < 0.001). Among the rats that received Campylobacter, 27% had evidence of bacterial overgrowth by PCR. These rats also had the highest prevalence of altered stool form and had lower body weight. Consistent with post-infectious IBS in humans, bacterial overgrowth rats demonstrated a significant increase in rectal and left colon intraepithelial lymphocytes. CONCLUSIONS: Acute infection with C. jejuni 81-176 precipitates alterations in stool consistency, bacterial overgrowth and rectal lymphocytosis consistent with findings in IBS patients.

Peptoniphilus gorbachii sp. nov., Peptoniphilus olsenii sp. nov., and Anaerococcus murdochii sp. nov. isolated from clinical specimens of human origin.

Three groups of previously unknown gram-positive, anaerobic, coccus-shaped bacteria were characterized using phenotypic and molecular taxonomic methods. Phenotypic and genotypic data demonstrate that these organisms are distinct, and each group represents a previously unknown subline within Clostridium cluster XIII. Two groups are most closely related to Peptoniphilus harei in the genus Peptoniphilus, and the other group is most closely related to Anaerococcus lactolyticus in the genus Anaerococcus. Based on the findings, three novel species, Peptoniphilus gorbachii sp. nov., Peptoniphilus olsenii sp. nov., and Anaerococcus murdochii sp. nov., are proposed. The type strains of Peptoniphilus gorbachii sp. nov., Peptoniphilus olsenii sp. nov., and Anaerococcus murdochii sp. nov. are WAL 10418(T) (= CCUG 53341(T) = ATCC BAA-1383(T)), WAL 12922(T) (= CCUG 53342(T) = ATCC BAA-1384(T)), and WAL 17230(T) (= CCUG 53340(T) = ATCC BAA-1385(T)), respectively.

Clostridium tertium isolated from gas gangrene wound; misidentified as Lactobacillus spp initially due to aerotolerant feature.

Clostridium tertium has been increasingly reported as a human pathogen. This organism is an aerotolerant Gram-positive rod that is often mistaken for other organisms, such as Lactobacillus or Bacillus species. We describe a case of a patient with a history of intravenous drug use presenting to UCLA-Olive View Medical Center with gas gangrene of both upper extremities. The organism was initially misidentified as a Lactobacillus species on aerobic culture plates. However, terminal spore formation was detected in this isolate on a sub-cultured anaerobic culture plate and this isolate was confirmed as C. tertium biochemically and genetically by 16S rDNA sequencing. Additional DNA cloning libraries made from the formalin-fixed specimen revealed Peptoniphilus species and an uncultured Clostridium clone, but not C. tertium. C. tertium might be a causative organism of gas-producing myonecrosis but such an association has never been described. Clinicians should be aware of the phenomenon of aerotolerance of some anaerobes and need to clarify the identification of organisms if the clinical picture does not fit the isolated organism.