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This paper presents the design and analysis of a biomimetic underwater snake-like robot, addressing the main limitations of current underwater robotic systems in terms of maneuverability and adaptability in complex environments. The innovative design incorporates flexible joint modules that significantly enhance the robot's ability to navigate through narrow and irregular terrains, which is a notable limitation in traditional rigidly connected underwater robots. These flexible joints provide increased degrees of freedom and enable the robot to absorb and release energy, ensuring stability even under external impacts, thus extending the operational lifespan of the robot. Finite element analysis demonstrates the flexible joints' superior performance in various underwater conditions, offering a greater range of motion and workspace compared to rigid connections. The results indicate that the robot's modular design, combined with the flexible joint module, leads to improved agility and maneuverability, allowing for precise and intentional operation. The control module, equipped with advanced sensors and a CPU, manages the complex dynamics introduced by the flexible joints, ensuring effective navigation and operation. The specific advantages of this design include the robot's enhanced structural integrity, its ability to conform to irregular surfaces, and its adaptability to environmental variations. The paper concludes with a discussion on the implications of these findings for the future design and operation of underwater serpentine robots, emphasizing the need for a balance between the effects of elastic modulus and workspace to maximize the benefits of flexible joints. [ABSTRACT FROM AUTHOR]

Background: The impact of the methylenetetrahydrofolate reductase (MTHFR) C677T mutation on the relationship between plasma homocysteine (Hcy) levels and stroke has been extensively studied and documented in previous study. However, it remains unclear whether the MTHFR C677T mutation can affect the response to Hcy lowering treatment in stroke patients with hyperhomocysteinemia (HHcy). Understanding the impact of genetic factors on treatment response can help optimize personalized treatment strategies for stroke patients with HHcy. We aimed to investigate the potential association between the MTHFR C677T gene polymorphisms and the effectiveness of Hcy lowering treatment using vitamin therapy in stroke patients with HHcy. Methods: The MTHFR C677T genotype polymorphisms were identified using polymerase chain reaction-restriction fragment length polymorphism, and the distribution of three genotypes in the MTHFR C677T gene locus was compared. The treatment effects of Hcy lowering agents were compared among patients with different genotypes. Results: Among the 320 stroke patients enrolled in the study, 258 (80.6%) were diagnosed with HHcy. Of these, 162 patients (Effective Group) responded well to the clinical Hcy lowering treatment, while 96 patients (Invalid Group) failed to achieve sufficient response even after taking combination supplements of folic acid, Vitamin B6, and methylcobalamin for one month. Significant differences were observed in terms of age (p < 0.001), hypertension (p = 0.034), dyslipidemia (p = 0.022), hyperuricemia (p = 0.013) and genotype distribution of MTHFR C677T gene polymorphism (p < 0.001) between the Invalid group and the Effective group. The multivariate regression analysis revealed that the T allele (odd rations [OR], 1.327; 95% confidence interval [CI], 1.114– 1.580; p = 0.0015) was independently associated with an insufficient Hcy lowering treatment effect. Additionally, the TT genotype was independently associated with insufficient response in both the codominant model (OR, 1.645; 95% CI, 1.093–2.476; p = 0.017) and the recessive model (TT versus CC + CT; OR, 1.529; 95% CI, 1.145–2.042; p = 0.004). However, no relationship was observed between CT + TT genotypes and poor treatment effect in the dominate model. Conclusions: Our findings suggested that the TT genotype and T allele of MTHFR C677T polymorphism were independently associated with an insufficient Hcy lowering treatment effect in stroke patients with HHcy. [ABSTRACT FROM AUTHOR]

Energy levels, Auger branching ratios, and radiative rates of the core-excited states of B-like carbon are calculated by the saddle-point variation and saddle-point complex-rotation methods. Relativistic and mass polarization corrections are included using first-order perturbation theory. Calculated Auger channel energies and branching ratios are used to identify high-resolution Auger spectrum in the 300-keV C+ → CH4 collision experiment. It is found that Auger decay of these five-electron core-excited states gives significant contributions to Auger spectrum in the range of 238-280 eV. [ABSTRACT FROM AUTHOR]

By systematic Rayleigh–Ritz variation calculations, the energies are reported for the core-excited states 1s2s2p2 5P and 1s2p3 5So in the Be-like isoelectronic sequence (Z = 11–20). Energy corrections, including the restricted variational method, mass polarisation, and relativistic effect, are considered to improve the accuracy of energy. The oscillator strengths and transition wavelength between these states are also reported. Computational data on hyperfine structures presented in this paper are calculated for the first time. [ABSTRACT FROM AUTHOR]

Primary familial brain calcification (PFBC) is a rare neurodegenerative disorder with four causative genes (SLC20A2, PDGFRB, PDGFB, and XPR1) that have been identified. Here, we aim to describe the mutational spectrum of four causative genes in a series of 226 unrelated Chinese PFBC patients. Mutations in four causative genes were detected in 16.8% (38/226) of PFBC patients. SLC20A2 mutations accounted for 14.2% (32/226) of all patients. Mutations in the other three genes were relatively rare, accounting for 0.9% (2/226) of all patients, respectively. Clinically, 44.8% of genetically confirmed patients (probands and relatives) were considered symptomatic. The most frequent symptoms were chronic headache, followed by movement disorders and vertigo. Moreover, the total calcification score was significantly higher in the symptomatic group compared to the asymptomatic group. Functionally, we observed impaired phosphate transport induced by seven novel missense mutations in SLC20A2 and two novel mutations in XPR1. The mutation p.D164Y in XPR1 might result in low protein expression through an enhanced proteasome pathway. In conclusion, our study further confirms that mutations in SLC20A2 are the major cause of PFBC and provides additional evidence for the crucial roles of phosphate transport impairment in the pathogenies of PFBC. We made a genetic diagnosis in 16.8% of PFBC probands and identified 30 mutations; Mutations in SLC20A2 are the major cause of PFBC, while the other three genes are relatively rare; Our findings also strongly support crucial roles of phosphate transport impairment in the pathogenies of PFBC. [ABSTRACT FROM AUTHOR]

Using the saddle-point variation and saddle-point complex-rotation methods, energies, radiative, and Auger rates are calculated for the doubly-excited states 1s23l4l′ of beryllium-like ions. The total wave function is expanded by the restricted variation method to saturate the functional space and improve the nonrelativistic energy. Relativistic corrections and mass polarization effects are taken into account by the first-order perturbation theory. The partial Auger rates for these states are studied. The calculated Auger electron energies are compared with the experimental results which are observed in high resolution electron spectroscopy. The total radiative rates and the total Auger rates for these doubly-excited states 1s23l4l′ in the beryllium-like ions are also analyzed along with the increase of atomic number Z. Calculated results show that the total Auger rates are several orders of magnitude larger than the total radiative rates for these low-Z systems. [ABSTRACT FROM AUTHOR]

The optimal photoacoustic probe design is the key to obtain highest imaging sensitivity in photoacoustic computed tomography. Two commonly used probe design types are dark- and bright-field designs. We proposed a design for photoacoustic probe called quasibright-field illumination and compared the performance of all three kinds of probes theoretically and experimentally. Our conclusion is that the proposed quasibright-field illumination photoacoustic probe is superior compared to the existing probe designs as demonstrated. However, each type of illumination should still have its own advantages under certain circumstances. The dark-field illumination is capable of minimizing surface interference signals and reducing their contributions to the background of deeper signals. Hence, it should perform better when imaging samples with high optical absorbance at the surface layer. The bright field may perform better under circumstance when phase distortion is less. We also designed and fabricated three kinds of probes using a single multimode optical fiber for laser energy delivery instead of fiber bundle. Single fiber probes are low cost, transmit laser energy efficiently, and are compact for easy handling. Thus, our study not only provides a method for probe design but also a guidance for cost-effective transducer array-based photoacoustic probe design and manufacturing in the future. [ABSTRACT FROM AUTHOR]

Codonopsis taxa, as a traditional Chinese medicinal and edible plant, has found expanding domestic and foreign applications in recent decades. However, the poor management in germplasm resources market has inevitably caused an unnecessary hybrid of the provenances. In order to clarify the hybrid characteristics of germplasm resources in the main production area, the Codonopsis cultivars collected from the provinces Gansu, Shannxi, Shanxi, and Hubei of China were researched, using internal transcribed spacer (ITS) sequence technology. The confirmation of additive nucleotides based on the ITS sequencing of polymerase chain reaction (PCR) mixture was optimized and used to study the hybrid of Codonopsis cultivars. The results showed that when the ratio of PCR mixture increased up to 15 percent, the presence of a double peak in the sequencing electrophoresis map could be confirmed, suggesting the existence of additive nucleotides. According to the method above, 46 samples of Codonopsis cultivars collected during 2016 and 2017 were studied and compared with the samples collected from the year 2009 to 2010. All of the samples collected during 2016 and 2017 were hybridized and no genetic pure lines were found. In addition, the sites of variable base reduced greatly, concentrating at positions 122 and/or 226. These phenomena suggested that the genetic diversity of Codonopsis cultivars declined and the germplasm resources gradually converged. More attention should be paid to the reasonable exploitation and genetic breeding of Codonopsis taxa. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Physics is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Physics is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Physics is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Coron et al applied batch technique to the fully homomorphic encryption scheme over the integers, which could ho-momorphicly process and encrypt a plaintext vector in a ciphertext and improved the efficiency of the original scheme. But it' s public-key size was Õ(λ8). In order to reduce the public-key size, combined with the quadratic forms of public key elements and the ciphertext compression technique, this paper presented a variant batch fully homomorphic encryption scheme over the integers, which the public-key size was Õ(λ8). The scheme had smaller public-key size. Finally, it proves that the scheme is semantically secure. [ABSTRACT FROM AUTHOR]

Energy levels, radiative rates, Auger branching ratios of the 1 s vacancy resonances 1 s2 s2 p and 1 s2 s2 pL (L = S, P, D) of the boron isoelectronic sequence including O, Ne, Mg, Si ions are calculated by the saddle-point variation and saddle-point complex-rotation methods. Large-scale wavefunctions are used to obtain reliable results. Relativistic corrections and mass polarisation effects are taken into account to get precise energy levels. Calculated X-ray wavelengths, radiative rates, Auger electron energies, and Auger rates for these core-excited states are compared with available theoretical and experimental results. Furthermore, calculated reliable X-ray wavelengths are used to give possible identifications for satellite lines in the X-ray spectrum of foil-excited magnesium and silicon ions. Calculated Auger electron energies and Auger branching ratios are used to identify oxygen and neon Auger electron spectral lines in previous collision experiments. Three unidentified experimental spectral lines in neon KLL Auger electron spectrum are identified in the present work. The total radiative rates and the total Auger rates for the 1 s2 s2 p and 1 s2 s2 p resonances of B-like ions are also discussed, as a function of atomic number Z. It is found that the total Auger rates of these resonances are several orders of magnitude larger than the total radiative rates for these low- Z ( Z = 6-14) ions. [ABSTRACT FROM AUTHOR]

Energies for the multiexcited states 1s22s2pnl and 1s22p2nl 4 Pe,o ( n ≥ 2) of B-like oxygen are calculated using Rayleigh-Ritz variation method with configuration interaction. The mass polarization and relativistic corrections are obtained with first-order perturbation theory. Configuration structures of the high-lying multiexcited series are identified by energies and contribution to normalization of angular-spin components. These structures are further checked by calculations of relativistic corrections and fine structure splittings. Hyperfine parameters and hyperfine coupling constants are calculated for the first time. Wavelengths including quantum electrodynamic effect and higher-order relativistic corrections and lifetimes are also calculated. These results are compared with available results in the literature. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012 [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Physics is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The variational method with mutilconfiguration interaction wave function is used to obtain the energies, fine structures, and hyperfine structures of high-lying core-excited quartet states 1s2lnl' 4Po(m) (m = 1–5) and 1s2pnp 4P(m) (m = 1–5) in Li-like N4+ and F6+ ions, including the mass polarization and relativistic corrections. Restricted variational method is carried out to extrapolate a better energy. The oscillator strengths, lifetime, wavelengths, fine structure, and hyperfine structure for this system are also investigated to compare with other theoretical and experimental data in the literature. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 [ABSTRACT FROM AUTHOR]

Microbial effects on phosphorus release were studied for the sediments of Tianjin source water by controlling DO and pH. The results show that: (1) In sterilised water, phosphorus began to release when pH = 9.1 and the stable release rate was 9.51 mg/(d·m2). It indicates that microorganisms may utilise anaerobic iron respiration to release Fe-P. (2) With unsterilised water, phosphorus release rate is 2.14 mg/(d·m2) when pH = 6.5, 8.60 mg/(d·m2) when pH is uncontrolled, and gets to 8.51 mg/(d·m2) when pH = 9.1. This indicates that microorganisms can dissolve insoluble phosphates to accelerate the ion exchange of OH- and PO43-, which are derived from iron-bound ortho-P and aluminium-bound ortho-P. [ABSTRACT FROM AUTHOR]

Variational calculations are carried out with a multiconfiguration-interaction wave function to obtain the relativistic energies of the 1s2 2 ln l 1S(m)(n =2–6, m1–5) states for the beryllium isoelectronic sequence (Z =4–10). Relativistic corrections and the mass polarization effects are evaluated with the first-order perturbation theory. The identifications of the energy levels for 1s2 2 ln l 1S(m)(n =2–6, m1–5) states in the Be-like ions are reported. The oscillator strengths, transition rates and wavelengths are also calculated. The calculated results are compared with other theoretical and experimental data in the literature. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Physics is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper we use numerical method to study the quantum effect of dynamical localization in a mesoscopic Josephson junction driven by a periodically external electromagnetic field. We find that the charge is localized effectively for the case when the ratio of the field magnitude and the field frequency is less than a certain value. In this case too the magnitude of the supercurrent remains a constant. [ABSTRACT FROM AUTHOR]

A constant sound speed (i.e., 1540 m/s) is generally used in various ultrasound (US) and photoacoustic (PA) image reconstruction algorithms based on the assumption of a homogeneous sound speed in human tissue. However, the variation of the sound speed in human tissue can be as great as 10%, which can lead to low contrast, distortion, and blurring in reconstruction images. We proposed an automatic method of selecting the mean sound speed based on optimum focusing of received PA signals to enhance the quality of reconstructed PA images. Optimum focusing is quantified by calculating the minimum sum of the deviation of beamformed PA signals from their mean value for various sound speeds. The proposed method was demonstrated by homogeneous and heterogeneous sound speed simulation models, and also evaluated by experiments with agar and porcine tissue-mimicking phantoms. The central vertical and lateral profiles of reconstructed absorbers verified the improvement of contrast, signal-to-noise ratio (SNR), and spatial resolution by using the estimated mean sound speed. [ABSTRACT FROM AUTHOR]

The relativistic energies, fine structures, hyperfine structures, Auger rates and widths of the core-excited states for the Li isoelectronic sequence (Z = 10-20) are studied using the saddle-point variational method and the saddle-point complex-rotation method. The oscillator strengths, radiative rates, wavelengths and lifetimes are also reported. Properties such as fine-structure splitting, radiative and Auger rate regularly change along the Li isoelectronic sequence are discussed. The results are compared with other theoretical and experimental data in the literature. [ABSTRACT FROM AUTHOR]

In this paper a relativistic many-body perturbation calculation is performed to calculate the hyperfine constants of the ground states for lithium-like isoelectronic sequence. Zeroth-order hyperfine constants are calculated with Dirac-Fock wavefunctions, and the finite basis sets of the Dirac-Fock equations are constructed by B splines. With the finite basis sets, the core polarization and the correlation effect are evaluated. [ABSTRACT FROM AUTHOR]