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High-quality-factor microring resonators are highly desirable in many applications. Fabricating a microring resonator typically requires delicate instruments to ensure a smooth side wall of waveguides and 100-nm critical feature size in the coupling region. In this work, we demonstrate a new method "damascene soft nanoimprinting lithography" that can create high-fidelity waveguide by simply backfill an imprinted cladding template with a high refractive index polymer core. This method can easily realize high Q-factor polymer microring resonators (e.g., ~5 x 105 around 770 nm wavelength) without the use of any expensive instruments and can be conducted in a normal lab environment. The high Q-factors can be attributed to the residual layer-free feature and controllable meniscus cross-section profile of the filled polymer core. Furthermore, the new method is compatible with different polymers, yields low fabrication defects, enables new functionalities, and allows flexible substrate. These benefits can broaden the applicability of the fabricated microring resonator.
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Phonon-based frequency combs that can be generated in the optical and microwave frequency domains have attracted much attention due to the small repetition rates and the simple setup. Here, we experimentally demonstrate a new type of phonon-based frequency comb in a silicon optomechanical crystal cavity including both a breathing mechanical mode (â¼GHz) and flexural mechanical modes (tens of MHz). We observe strong mode competition between two approximate flexural mechanical modes, i.e., 77.19 and 90.17 MHz, resulting in only one preponderant lasing, while maintaining the lasing of the breathing mechanical mode. These simultaneous observations of two-mode phonon lasing state and significant mode competition are counterintuitive. We have formulated comprehensive theories to elucidate this phenomenon in response to this intriguing outcome. In particular, the self-pulse induced by the free carrier dispersion and thermo-optic effects interacts with two approximate flexural mechanical modes, resulting in the repetition rate of the comb frequency-locked to exact fractions of one of the flexural mechanical modes and the mode hopping between them. This phonon-based frequency comb has at least 260 comblines and a repetition rate as low as a simple fraction of the flexural mechanical frequency. Our demonstration offers an alternative optomechanical frequency comb for sensing, timing, and metrology applications.
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Objective: To assess the effectiveness of using mobile health platforms for continuous care in preventing and treating osteoporosis. Methods: 114 patients with osteoporosis admitted to Nantong First People's Hospital from March 2021 to June 2022 were recruited and assigned equally via random number table method to receive either routine care (namely education on osteoporosis disease, dietary guidance, exercise guidance, activity guidance, medication supervision, fall prevention, psychological care, and secondary health education at the time of discharge) (routine group) or mobile health platform-based continuity of care (continuity group), with 57 patients in each group. Outcome measures included treatment compliance, disease knowledge of osteoporosis (diet, exercise, risk factors), quality of life level, and care satisfaction. Results: All eligible patients were followed up for one year after discharge from the hospital. Patients with continuity of care showed higher treatment compliance and disease knowledge of diet, exercise, and risk factors than those with routine care (P = .004). Continuity of care was associated with significantly higher MOS 36-item short-form health survey (SF-36) scores (The SF-36 is a self-administered questionnaire containing 36 items that survey overall health status) and nursing satisfaction in patients versus routine care (P = .004). Conclusion: Mobile health platform-based continuity of care effectively enhances post-discharge compliance and knowledge of osteoporosis in patients with osteoporosis, thereby improving post-discharge quality of life and satisfaction with care. Multi-center studies involving diverse healthcare settings and patient populations would provide more robust evidence. Moreover, these findings highlight the potential benefits of incorporating mobile health platforms into the care continuum for osteoporosis patients. Also, by utilizing mobile health platforms, healthcare providers can extend their reach beyond hospital settings and provide continuous care and support to patients, potentially reducing the burden on healthcare systems and improving overall population health outcomes.
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An optical frequency comb is a spectrum of optical radiation which consists of evenly spaced and phase-coherent narrow spectral lines and is initially invented in a laser for frequency metrology purposes. A direct analog of frequency combs in the magnonic systems has not been demonstrated to date. In our experiment, we generate a new magnonic frequency comb in the resonator with giant mechanical oscillations through the magnomechanical interaction. We observe the magnonic frequency comb contains up to 20 comb lines, which are separated by the mechanical frequency of 10.08 MHz. The thermal effect based on the strong pump power induces the cyclic oscillation of the magnon frequency shift, which leads to a periodic oscillation of the magnonic frequency comb. Moreover, we demonstrate the stabilization and control of the frequency spacing of the magnonic frequency comb via injection locking. Our Letter lays the groundwork for magnonic frequency combs in the fields of sensing and metrology.
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Piezoelectric accurate actuation plays an important role in industrial applications. The intrinsic frequency of previous actuators is invariable. However, variable frequency can approach the range near the low-intrinsic-frequency and realize a high actuation capability. The frequency-variable linear and rotary motion (FVLRM) principle is proposed for rotor-blade-based two-degree-of-freedom driving. Inertial force is generated by frequency-variable piezoelectric oscillators (FVPO), the base frequency and vibration modes of which are adjustable by the changeable mass and position of the mass block. The variable-frequency principle of FVPO and the FVLRM are recognized and verified by the simulations and experiments, respectively. The experiments show that the FVLRM prototype moves the fastest when the mass block is placed at the farthest position and the prototype is at the second-order intrinsic frequencies of 42 Hz and 43 Hz, achieving a linear motion of 3.52 mm/s and a rotary motion of 286.9 mrad/s. The actuator adopts a lower operating frequency of less than 60 Hz and has the function of adjusting the natural frequency. It can achieve linear and rotational motion with a larger working stroke with 140 mm linear movement and 360° rotation.
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Mechanical degrees of freedom, which have often been overlooked in various quantum systems, have been studied for applications ranging from quantum information processing to sensing. Here, we develop a hybrid platform consisting of a magnomechanical cavity and an optomechanical cavity, which are coherently coupled by the straightway physical contact. The phonons in the system can be manipulated either with the magnetostrictive interaction or optically through the radiation pressure. Together with mechanical state preparation and sensitive readout, we demonstrate the microwave-to-optical conversion with an ultrawide tuning range up to 3 GHz. In addition, we observe a mechanical motion interference effect, in which the optically driven mechanical motion is canceled by the microwave-driven coherent motion. Manipulating mechanical oscillators with equal facility through both magnonic and photonic channels enables new architectures for signal transduction between the optical, microwave, mechanical, and magnetic fields.
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Ferroelectric materials have aroused the researchers' great interest due to their wide applications. Here, a displacement-type ferroelectric-ferroelectric phase transition material [(NH3)(CH2)3(NH3)]2[InBr6]Br·H2O (1) with Tc = 143 K was successfully prepared. The ferroelectric phase transition is verified by the characterization techniques such as differential scanning calorimetry, single-crystal structure elucidation, dielectric and ferroelectric measurements. The single-crystal structure elucidation reveals that the displacement and distortion of [(NH3)(CH2)3(NH3)]2+ cations lead to the phase transition from Cmc21 to Pca21. The spontaneous polarizations at 293 and 133 K are 0.15 and 0.12 µC·cm-2, respectively. We expect that this work will help in further exploration of some new ferroelectric materials.
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Given the serious threat of foodborne multidrug-resistant bacteria to animals and humans, finding an effective antibacterial compound has always been an important topic for scientists. Here, from the soil of Changbaishan, we have identified a bacterium that can inhibit the growth of Staphylococcus aureus. Nr genome database analysis and phylogenetic analysis showed that strain CB6 belongs to Bacillus velezensis. We found that the crude extract of strain CB6 has broad-spectrum antibacterial activity against foodborne pathogens. In addition, we showed that the crude extract loses antibacterial activity after treatment with papain. Next, strain CB6 was purified using ammonium sulfate precipitation, a Sephadex G-75 gel filtration column and high-performance liquid chromatography system (HPLC). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis indicated that the antibacterial compound was the protein ATP synthase subunit α (ATP-1), with a molecular weight of 55.397 KDa. Moreover, we reported the complete genome sequence of strain CB6, which is composed of a unique circular 3,963,507 bp chromosome with 3749 coding genes and a G + C content of 46.53%. The genome contained 12 gene clusters with antibacterial functions, which constituted over 20.947% of the complete genome. Of note, the amino acid sequence encoding the ATP-1 protein in the strain CB6 genome was identified. In addition to these findings, we speculate that the ATP-1 protein may provide energy for secondary metabolites, which in turn will improve the antibacterial activity of the secondary metabolites. All the above important features make the ATP-1 as a potential candidate for the development of new antibacterial drugs and food preservatives in the future.
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Antibiosis , Bacillus/enzimología , Bacillus/genética , Microbiología de Alimentos , ATPasas de Translocación de Protón Mitocondriales/genética , Antibacterianos/farmacología , Antiinfecciosos/metabolismo , Antiinfecciosos/farmacología , Cromatografía Liquida , Enfermedades Transmitidas por los Alimentos/microbiología , Genoma Bacteriano/efectos de los fármacos , ATPasas de Translocación de Protón Mitocondriales/aislamiento & purificación , ATPasas de Translocación de Protón Mitocondriales/metabolismo , Filogenia , Staphylococcus aureus/efectos de los fármacos , Espectrometría de Masas en Tándem , Secuenciación Completa del GenomaRESUMEN
AIMS: We aimed to assess the comparative efficiency and safety of the use of glyburide, metformin, and insulin in gestational diabetes mellitus (GDM). METHODS: We searched for randomized controlled trials that compared glyburide, metformin, and insulin in GDM. Data regarding glycemic control and neonatal safety were collected and analyzed in pairwise and network meta-analyses. RESULTS: A total of 4533 individuals from 23 trials were included. Compared with glyburide, metformin reduced 2-h postprandial blood glucose (2HPG) to a greater extent (standard mean difference (SMD) 0.18; 95% credible interval (CI) 0.01, 0.34). There were significantly lower prevalence of neonatal hypoglycemia (risk difference (RD) - 0.07; 95%CI - 0.11, - 0.02) and preeclampsia (RD - 0.03; 95%CI - 0.06, 0) in the metformin group than in the insulin group. The metformin group had significantly lower birth weight (SMD - 0.17; 95%CI - 0.25, - 0.08) and maternal weight gain (SMD - 0.61; 95%CI - 0.86,- 0.35) compared with the insulin group. Network meta-analysis suggested that metformin had the highest probability of successfully controlling glycemia and preventing neonatal complications. CONCLUSIONS: The present meta-analysis suggests that metformin may be as effective as insulin for glycemic control and is the most promising drug for the prevention of neonatal and maternal complications.
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Diabetes Gestacional/tratamiento farmacológico , Control Glucémico , Hipoglucemiantes/uso terapéutico , Resultado del Embarazo/epidemiología , Adulto , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Diabetes Gestacional/epidemiología , Femenino , Gliburida/uso terapéutico , Control Glucémico/métodos , Control Glucémico/estadística & datos numéricos , Humanos , Hipoglucemiantes/clasificación , Recién Nacido , Enfermedades del Recién Nacido/epidemiología , Enfermedades del Recién Nacido/etiología , Insulina/uso terapéutico , Masculino , Análisis por Apareamiento , Metformina/uso terapéutico , Metaanálisis en Red , Embarazo , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricosRESUMEN
3D point reconstruction is a crucial component in optical inspection. A direct reconstruction process is proposed by combining two similarity invariants in active vision. A planar reference with an isosceles-right-angle pattern and a coplanar laser are adopted to generate the laser projective point on the measured object. The first invariant is the image of the conic dual to the circular points (ICDCP), which is derived from the lines in two pairs of perpendicular directions on the reference pattern. The invariant provides the transform from the projection space to the similarity space. Then, the ratio of the line segments consisting of the laser projection points and reference points is constructed as the other similarity invariant, by which the laser projection point in the similarity space is converted to Euclidean space. The solution of the laser point is modeled by the ratio invariant of the line segments and improved by a special point selection to avoid nonlinear equations. Finally, the benchmark-camera distance, the benchmark-generator distance, the benchmark length, image noise, and the number of orthogonal lines are experimentally investigated to explore the effectiveness and reconstruction error of the method. The reconstruction error averages of 0.94, 1.22, 1.77, and 2.15â mm are observed from the experiment results with the benchmark-camera distances from 600â mm to 750â mm with a 50â mm interval. This proves the validity and practicability of the reconstruction method.
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The diagnosis of aggressive prostate cancer (PCa) has relied on microscopic architectures, namely Gleason patterns, of tissues extracted through core biopsies. Technology capable of assessing the tissue architecture without tissue extraction will reduce the invasiveness of PCa diagnosis and improve diagnostic accuracy by allowing for more sampling locations. Our recently developed photoacoustic spectral analysis (PASA) has achieved quantification of tissue architectural heterogeneity interstitially. Taking advantage of the unique optical absorption of cell nuclei at ultraviolet (UV) wavelengths, this study investigated PASA at 266 nm for quantifying the tissue architecture heterogeneity in prostates. The results have shown significant differences among the normal, early cancer, and late cancer stages in mouse prostates ex vivo and in vivo (n=20, p<0.05). The study with human samples ex vivo has shown a correlation of 0.80 (n=11, p<0.05) between PASA quantification and pathologic diagnosis.
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Técnicas Fotoacústicas/métodos , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Rayos Ultravioleta , Animales , Línea Celular Tumoral , Humanos , Masculino , Ratones , Clasificación del Tumor , Estadificación de NeoplasiasRESUMEN
Brown adipose tissue (BAT) is an exclusive tissue of nonshivering thermogenesis. It is fueled by lipids and glucose and involved in energy and metabolic homeostasis. Intrauterine exposure to hyperglycemia during gestational diabetes mellitus may result in abnormal fetal development and metabolic phenotypes in adulthood. However, whether intrauterine hyperglycemia influences the development of BAT is unknown. In this study, mouse embryos were exposed to the intrauterine hyperglycemia environment by injecting streptozocin into pregnant mice at 1 d post coitum (dpc). The structure of BAT was examined by hematoxylin and eosin staining and immunohistochemical analysis. The glucose uptake in BAT was measured in vivo by [18F]-fluoro-2-deoxyglucose-micro-positron emission tomography. The gene expression in BAT was determined by real-time PCR, and the 5'-C-phosphate-G-3' site-specific methylation was quantitatively analyzed. Intrauterine hyperglycemia exposure resulted in the impaired structure of BAT and decreased glucose uptake function in BAT in adulthood. The expressions of the genes involved in thermogenesis and mitochondrial respiratory chain in BAT, such as Ucp1, Cox5b, and Elovl3, were down-regulated by intrauterine hyperglycemia exposure at 18.5 dpc and at 16 wk of age. Furthermore, higher methylation levels of Ucp1, Cox5b, and Elovl3 were found in offspring of mothers with streptozotocin-induced diabetes. Our results provide the evidence for enduring inhibitory effects of intrauterine hyperglycemia on BAT development in offspring. Intrauterine hyperglycemia is associated with increased DNA methylation of the BAT specific genes in offspring, which support an epigenetic involvement.-Yu, D.-Q., Lv, P.-P., Yan, Y.-S., Xu, G.-X., Sadhukhan, A., Dong, S., Shen, Y., Ren, J., Zhang, X.-Y., Feng, C., Huang, Y.-T., Tian, S., Zhou, Y., Cai, Y.-T., Ming, Z.-H., Ding, G.-L., Zhu, H., Sheng, J.-Z., Jin, M., Huang, H.-F. Intrauterine exposure to hyperglycemia retards the development of brown adipose tissue.
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Tejido Adiposo Pardo/fisiopatología , Hiperglucemia/fisiopatología , Útero/fisiopatología , Tejido Adiposo Pardo/metabolismo , Animales , Metilación de ADN/fisiología , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/fisiopatología , Diabetes Gestacional/inducido químicamente , Diabetes Gestacional/metabolismo , Diabetes Gestacional/fisiopatología , Transporte de Electrón/fisiología , Femenino , Expresión Génica/fisiología , Glucosa/metabolismo , Hiperglucemia/metabolismo , Ratones , Ratones Endogámicos ICR , Embarazo , Estreptozocina/farmacología , Termogénesis/fisiología , Útero/metabolismoRESUMEN
Aeromonas veronii is a major pathogenic bacterium in humans and animals. When it causes outbreaks, there are enormous economic losses to the aquaculture industry. An effective live attenuated vaccine strain, ΔhisJ, was obtained in our previous studies by gene knockout in Aeromonas veronii TH0426 using the suicide vector pRE112. Here, we evaluated whether the live attenuated vaccine ΔhisJ was suitable for prevention of Aeromonas veronii infection by injection and immersion in loaches. Compared with that of the TH0426 wild-type strain, the virulence of the live vaccine was significantly weakened. Vaccine safety assessment results also indicated that 1 × 107 CFU/mL live vaccine was safe and did not induce clinical symptoms or obvious pathological changes. Additionally, after challenging loaches with Aeromonas veronii TH0426, the relative percent survival of the IN3 injection group was 65.66%, and that of the IM group was 50.78%. Our data show that the live attenuated vaccine ΔhisJ can improve the immune protection rate of loaches. Furthermore, increased enzyme activity parameters (SOD, LZM, ACP, and AKP) in the skin mucus, increased enzyme activity parameters (SOD, LZM, ACP, AKP, and GPx) in the serum, increased specific IgM antibodies and cytokine IL-1ß contents in the serum, and increased cytokine (IL-15, pIgR, IL-1ß, and TNF-α) expression in the liver and spleen were observed. These data are the first to indicate that the live attenuated vaccine ΔhisJ is suitable for the development of a safe and effective vaccine against Aeromonas veronii infection in loach aquaculture.
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Aeromonas veronii/inmunología , Vacunas Bacterianas/administración & dosificación , Cipriniformes/inmunología , Enfermedades de los Peces/prevención & control , Infecciones por Bacterias Gramnegativas/prevención & control , Vacunas Atenuadas/administración & dosificación , Animales , Anticuerpos Antibacterianos/sangre , Citocinas/sangre , Citocinas/genética , Citocinas/inmunología , Infecciones por Bacterias Gramnegativas/veterinaria , Inmunoglobulina M/sangre , Dosificación Letal Mediana , Hígado/inmunología , Piel/inmunología , Bazo/inmunologíaRESUMEN
Nicotinic acid adenosine dinucleotide phosphate (NAADP) is a Ca2+-mobilizing second messenger that regulates a wide range of biological activities. However, the mechanism of its biogenesis remains controversial. CD38 is the only enzyme known to catalyze NAADP synthesis from NADP and nicotinic acid. CD38-mediated catalysis requires an acidic pH, suggesting that NAADP may be produced in acidic endolysosomes, but this hypothesis is untested. In this study, using human cell lines, we specifically directed CD38 to the endolysosomal system and assessed cellular NAADP production. First, we found that nanobodies targeting various epitopes on the C-terminal domain of CD38 could bind to cell surface-localized CD38 and induce its endocytosis. We also found that CD38 internalization occurred via a clathrin-dependent pathway, delivered CD38 to the endolysosome, and elevated intracellular NAADP levels. We also created a CD38 variant for lysosome-specific expression, which not only withstood the degradative environment in the lysosome, but was also much more active than WT CD38 in elevating cellular NAADP levels. Supplementing CD38-expressing cells with nicotinic acid substantially increased cellular NAADP levels. These results demonstrate that endolysosomal CD38 can produce NAADP in human cells. They further suggest that CD38's compartmentalization to the lysosome may allow for its regulation via substrate access, rather than enzyme activation, thereby providing a reliable mechanism for regulating cellular NAADP production.
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ADP-Ribosil Ciclasa 1/metabolismo , Calcio/metabolismo , Endocitosis , Lisosomas/metabolismo , Glicoproteínas de Membrana/metabolismo , NADP/análogos & derivados , ADP-Ribosil Ciclasa 1/genética , Señalización del Calcio , Células HEK293 , Células HeLa , Humanos , Glicoproteínas de Membrana/genética , NADP/metabolismo , Niacina/farmacología , Anticuerpos de Dominio Único/administración & dosificación , Vasodilatadores/farmacologíaRESUMEN
The active-vision-based reconstruction is an advanced approach to characterize the spatial object. In the active vision, the planar laser is a kind of the moderate structured light for the robustness and adaptivity in the complicated illumination environment. However, as the planar laser is determined by 3 unknown degrees of freedom, the laser sensor should be calibrated in the immovable coordinate frame of reference (CFR), or be pre-calibrated in the coordinate frame of the camera (CFC) and moved with CFC. In the study, as the main improvement, the laser plane is attached to the simple 2D reference without strict constraints of the relative installation position and posture. The laser plane is desired to be flexibly moved and registered in CFC. The calibration is modeled by the closed loop of the camera, the cylindrical object, the planar laser and the 2D reference, in which the camera is twice considered as the bridge between the cylindrical object and the 2D reference. The calibration contributes the planar laser that is determined as a constant vector in CFR. Furthermore, the reconstruction is performed by the calibrated laser plane and refined by the optimization method. The method errors of 1.263, 1.517, 1.633, and 1.803 mm are evaluated by the experiments, which indicate the flexibility of the method and applicable prospects in the spatial reconstruction field.
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We isolated five novel bacterial strains from symptomatic bark tissue of Populus × euramericana canker that were Gram-stain-negative, non-motile, aerobic oxidase-negative and catalase-positive. Growth occurred at 10-41 °C and at pH 5.0-7.0, with optimum growth at 30 °C and pH 7.0. Additionally, growth occurred in conditions of 0-5â% (w/v) salinity, but not above 7â% NaCl. The 16S rRNA gene sequences of the novel strains shared the highest similarity with Sinorhodobacter ferrireducens SgZ-3T (97.1â%). The average nucleotide identity values between the novel strains and two type strains (S.inorhodobacter ferrireducens CCTCC AB2012026T and 'Sinorhodobacter hungdaonensis' CGMCC 1.12963T) were 78.4-78.9â%, which were lower than the proposed species boundary cut-off (95-96â%). The main polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified lipid and phosphatidylcholine. The main respiratory quinone was Q-10, and major fatty acids were C18â:â1ω7c and/or C18â:â1ω6c. Based on data from a polyphasic taxonomy study, the novel strains represent a novel species of the genus Sinorhodobacter, for which the name Sinorhodobacter populi sp. nov. is proposed. The type strain is sk2b1T (=CFCC 14580T=KCTC 52802T).
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Filogenia , Corteza de la Planta/microbiología , Enfermedades de las Plantas/microbiología , Populus/microbiología , Rhodobacteraceae/clasificación , Técnicas de Tipificación Bacteriana , Composición de Base , Cardenólidos/química , China , ADN Bacteriano/genética , Ácidos Grasos/química , Fosfolípidos/química , ARN Ribosómico 16S/genética , Rhodobacteraceae/aislamiento & purificación , Análisis de Secuencia de ADNRESUMEN
Laser-plane-based vision reconstruction is an important approach for 3D profile measurement and optical inspection. This study develops a 3D reconstruction method to measure the object with a flexible method. The active vision reconstruction includes an external camera and a 3D reference with an internal camera and laser projector. The 3D calibration object, the external camera, and the 3D reference constitute a closed loop. The internal camera, the 3D calibration object, and the 3D reference compose the other closed loop. The intrinsic invariants of the 3D reference with an internal camera and laser projector are determined by the two loops above. The benefit of the method is to cancel the position constraint for the active vision system with the cubic LED reference and the monocular external camera. Furthermore, as the external camera captures only the images of the 3D reference, the reconstruction system of the projector and the camera is flexible to observe the occlusion location on the measured object. The methods, including the calibration model and reconstruction model of the measurement system, are verified by experiments to demonstrate the potential applications.
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A flexible reconstruction method, which is based on the line re-projection errors of the laser plane, is presented for the profile recovery. The bi-cuboid references are designed to cover the large view-field of the camera. The local intrinsic and extrinsic parameter matrices of the camera are initially contributed by the RQ decomposition. Then the balance model is demonstrated to obtain the global parameter matrices in view of the refined projection in the camera coordinate system. The flexible laser plane is solved by the Plücker matrices of the projection laser lines that are generated from the homographies of the cubical references and the global parameter matrices. Furthermore, the laser plane and global parameter matrices are improved by the cost function that is constructed by the re-projection errors of the parameterized laser lines on the references. The reconstruction experiments are performed to verify the validity and the accuracy of the optimization method and the initial method. The impact factors of the measurement distance, the reference distance and the test distance are investigated in the experiments. The average reconstruction errors are 1.14 mm, 1.13 mm, 1.15 mm and 1.17 mm in the four groups of experiments, which shows the good application prospect of the profile reconstructions.
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A Gram-stain negative, aerobic, non-motile bacterial strain, 23D10-4-9T, was isolated from symptomatic canker bark tissue of Populus × euramericana. The isolate grew between 4 and 35 °C, with optimal growth occurring at 25 °C. The species was positive for catalase and negative for oxidase activity. Nitrate was not reduced to nitrite. It showed activities toward ß-galactosidase and ß-glucosidase. Citrate was not utilized. Acid was produced from d-glucose. The major fatty acids were iso-C15â:â0, C16â:â1ω7c and iso-C17â:â0 3-OH. The main polar lipid profiles of the novel isolate included phosphatidylethanolamine, phospholipids and seven unknown lipids. The predominant menaquinone of the novel isolate was MK-7. The DNA G+C content was 40.6 mol%. 16S rRNA gene data revealed that the novel isolate shares the greatest sequence similarity with Sphingobacterium populi 7Y-4T (96.1â%). Based on phenotypic and genotypic characteristics, the isolate represents a novel species within the genus Sphingobacterium, for which the name Sphingobacteriumcorticis sp. nov. is proposed. The type strain is 23D10-4-9T (=CFCC 12640T=KCTC 42248T).
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Filogenia , Corteza de la Planta/microbiología , Populus/microbiología , Sphingobacterium/clasificación , Técnicas de Tipificación Bacteriana , Composición de Base , China , ADN Bacteriano/genética , Ácidos Grasos/química , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Sphingobacterium/genética , Sphingobacterium/aislamiento & purificación , Vitamina K 2/análogos & derivados , Vitamina K 2/química , beta-Galactosidasa/metabolismo , beta-Glucosidasa/metabolismoRESUMEN
Skeleton-diversity-oriented chemical conversion from pure natural products is a valuable method to obtain natural product-like compounds, especially those with novel architecture. The application of phytochemical methods to iridoids yielded three novel secoiridoid dimers: sweritranslactones A-C (1-3). These molecules possess a 6/6/6/6/6/6-fused hexacyclic skeleton and were obtained from swertiamarin, one of the major constituents of the genus Swertia, via a [4 + 2] cycloaddition and intramolecular nucleophilic addition under aqueous conditions. The structures were established based on extensive spectroscopic characterization and X-ray crystallographic diffraction analysis.