BACKGROUND Sigmoid colon cancer faces challenges due to anatomical diversity,including variable inferior mesenteric artery(IMA)branching and tumor localization complexities,which increase intraoperative risks.AIM To c...BACKGROUND Sigmoid colon cancer faces challenges due to anatomical diversity,including variable inferior mesenteric artery(IMA)branching and tumor localization complexities,which increase intraoperative risks.AIM To comprehensively evaluate the impact of three-dimensional(3D)visualization technology on enhancing surgical precision and safety,as well as optimizing perioperative outcomes in laparoscopic sigmoid cancer resection.METHODS A prospective cohort of 106 patients(January 2023 to December 2024)undergoing laparoscopic sigmoid cancer resection was divided into the 3D(n=55)group and the control(n=51)group.The 3D group underwent preoperative enhanced computed tomography reconstruction(3D Slicer 5.2.2&Mimics 19.0).3D reconstruction visualization navigation intraoperatively guided the following key steps:Tumor location,Toldt’s space dissection,IMA ligation level selection,regional lymph node dissection,and marginal artery preservation.Outcomes included operative parameters,lymph node yield,and recovery metrics.RESULTS The 3D group demonstrated a significantly shorter operative time(172.91±20.69 minutes vs 190.29±32.29 minutes;P=0.002),reduced blood loss(31.5±11.8 mL vs 44.1±23.4 mL,P=0.001),earlier postoperative flatus(2.23±0.54 days vs 2.53±0.61 days;P=0.013),shorter hospital length of stay(13.47±1.74 days vs 16.20±7.71 days;P=0.013),shorter postoperative length of stay(8.6±2.6 days vs 10.5±4.9 days;P=0.014),and earlier postoperative exhaust time(2.23±0.54 days vs 2.53±0.61 days;P=0.013).Furthermore,the 3D group exhibited a higher mean number of lymph nodes harvested(16.91±5.74 vs 14.45±5.66;P=0.030).CONCLUSION The 3D visualization technology effectively addresses sigmoid colon anatomical complexity through surgical navigation,improving procedural safety and efficiency.展开更多
A new type of implantable drug delivery devices （ DDD ） with complicated architectures were fubricated by three-dimensional printing technique, employing levofloxacin （LVFX） as a model drug. Processing parameters...A new type of implantable drug delivery devices （ DDD ） with complicated architectures were fubricated by three-dimensional printing technique, employing levofloxacin （LVFX） as a model drug. Processing parameters were optimized in riew of the layer thickness, spucing between printed lines, flow rate of liquid binder and the fast axis speed. The prepared DDD prototype consists of a double-layer structure, of which the upper region is a reservoir system and the lower region is a matrix one. The in vitro release test revealed that LVFX was released in a dual-puse pattern. This DDD may present a new strategy for the prophylaxis and treatment of diseases such as bone infection in the near future.展开更多
Three-dimensional holographic vector of atomic interaction field（3D-HoVAIF） is used to describe the chemical structures of polychlorinated naphthalenes（PCNs）.After variable screening by stepwise multiple regressio...Three-dimensional holographic vector of atomic interaction field（3D-HoVAIF） is used to describe the chemical structures of polychlorinated naphthalenes（PCNs）.After variable screening by stepwise multiple regression（SMR） technique,the liner relationships between gas-chromatographic relative retention time（RRT）,298 K supercooled liquid pressures（logPL）,n-octanol/air partition coefficient（logKOA）,n-octanol/water partition coefficient（logKOW）,aqueous solubilities（logSW）,relative in vitro potency values（-logEROD） of PCNs and 3D-HoVAIF descriptors have been established by partial least-square（PLS） regression.The result shows that the 3D-HoVAIF descriptors can be well used to express the quantitative structure-property（activity） relationships of PCNs.Predictive capability of the models has also been demonstrated by leave-one-out cross-validation.Moreover,the predicted values have been presented for those PCNs which are lack of experimentally physico-chemical properties and biological activity by the optimum models.展开更多
The title complex Mn（H2O）2（HNic）2 （C22H12MnN2O8, Mr = 367.18） crystallizes in monoclinic, space group P21/c with a = 7.5735（8）, b = 12.5295（13）, c = 7.6466（8）A.β = 101.2790（10）°, Z = 2, V= 711.59...The title complex Mn（H2O）2（HNic）2 （C22H12MnN2O8, Mr = 367.18） crystallizes in monoclinic, space group P21/c with a = 7.5735（8）, b = 12.5295（13）, c = 7.6466（8）A.β = 101.2790（10）°, Z = 2, V= 711.59（13） A^3, D, = 1.714 g/cm^3,μ（MoKa） = 0.974 mm^-1, F（000） = 374, R1 （1255 observed reflections （Ⅰ 〉 2σ（Ⅰ）） = 0.0250） and wR2 = 0.0662 （all data）. In this paper, we report the complexation of Mn（Ⅱ） by the bidentate ligand 2-hydroxynicotinic acid （HNic）. In the crystal the Mn（Ⅱ） ion exhibits a deformed octahedron structure. The title complex Mn（H2O）2（HNic）2 has a three-dimensional （3D） network structure extended by hydrogen bonds, which are formed by two typical eight-membered hydrogen-bonded rings.展开更多
Some functional lanthanide metal complexes, such as acetylacetonato complexes, ethylenediaminetetraacetato complexes, were successfully applied for diagnostic technique. The authors are interested in investigating the...Some functional lanthanide metal complexes, such as acetylacetonato complexes, ethylenediaminetetraacetato complexes, were successfully applied for diagnostic technique. The authors are interested in investigating the structure and bonding in lanthanide and actinide metal complexes using 166Er, t55Gd, and 237Np Mtissbauer spectroscopies in connection with single-crystal and/or powder X-ray diffraction, making clear the differences on their structures as well as the differences in the participation of 4f and 5f orbitals in the chemical bonds. In this article, the crystal structures of two novel Gd（Ⅲ） acetylacetonato complexes, Gd（pta）3 · 2H2O （pta = 1,1,1 -trifluoro-5,5-dimethy 1-2,4-hexanedione） and Gd（bfa）3 · 2H2O （bfa = 1, 1, 1 -trifluoro-4-phenyl-2-4-butanedione） were reported. Though both of them were dihydrate and had distorted square antiprismatical structure, Gd（pta）3 · 2H2O crystallizes in the P 2 1/n （#14） monoclinic space group and its lattice parameters are a = 1.4141（6） nm, b = 1.0708（3） nm, c =2.2344（4） nm, β =952.4（2）°, and Gd（bfa）3· 2H2O crystallizes in P 212121 orthorhombic space group and its lattice parameters were a = 1.322 （1） nm, b = 2.295 （1） nm, c = 1. 0786（8） nm. In the meantime, the authors had finished a systematic investigation on the ^155Gd Mossbauer isomer shift （δ） of various Gd（Ⅲ） metal complexes having a different coordination number （C.N.） and different ratios coordinating oxygen to nitrogen. A tendency for the 6 value to decrease with an increase in the C.N, and the number of the nitrogen atom coordinating to Gd was confirmed. This indicated that the Gd-O and/or Gd-N bond in the investigated Gd（Ⅲ） metal complexes had a small covalent contribution, which was possible to be deduced from the O and/or N atoms of the lisands donating electrons to 6s, 5d, and 4f orbitals of Gd.展开更多
Our purpose in this study was to develop an automated method for measuring three-dimensional (3D) cerebral cortical thicknesses in patients with Alzheimer’s disease (AD) using magnetic resonance (MR) images. Our prop...Our purpose in this study was to develop an automated method for measuring three-dimensional (3D) cerebral cortical thicknesses in patients with Alzheimer’s disease (AD) using magnetic resonance (MR) images. Our proposed method consists of mainly three steps. First, a brain parenchymal region was segmented based on brain model matching. Second, a 3D fuzzy membership map for a cerebral cortical region was created by applying a fuzzy c-means (FCM) clustering algorithm to T1-weighted MR images. Third, cerebral cortical thickness was three- dimensionally measured on each cortical surface voxel by using a localized gradient vector trajectory in a fuzzy membership map. Spherical models with 3 mm artificial cortical regions, which were produced using three noise levels of 2%, 5%, and 10%, were employed to evaluate the proposed method. We also applied the proposed method to T1-weighted images obtained from 20 cases, i.e., 10 clinically diagnosed AD cases and 10 clinically normal (CN) subjects. The thicknesses of the 3 mm artificial cortical regions for spherical models with noise levels of 2%, 5%, and 10% were measured by the proposed method as 2.953 ± 0.342, 2.953 ± 0.342 and 2.952 ± 0.343 mm, respectively. Thus the mean thicknesses for the entire cerebral lobar region were 3.1 ± 0.4 mm for AD patients and 3.3 ± 0.4 mm for CN subjects, respectively (p < 0.05). The proposed method could be feasible for measuring the 3D cerebral cortical thickness on individual cortical surface voxels as an atrophy feature in AD.展开更多
The novel benzo-18-crown-6(B18-C-6)complex;{[Na(Bl8-C-6)]_(6)[Pt(SCN)_(6)]}[Pt(SCN)_(6)](SCN)_(2)(1)was synthesized and characterized by elemental analysis,IR spectrum and x-ray diffraction analysis.Thr crystal struct...The novel benzo-18-crown-6(B18-C-6)complex;{[Na(Bl8-C-6)]_(6)[Pt(SCN)_(6)]}[Pt(SCN)_(6)](SCN)_(2)(1)was synthesized and characterized by elemental analysis,IR spectrum and x-ray diffraction analysis.Thr crystal structure belongs to rhomobohedral,space group R-3 with cell dimesions:a=6=1.9933(3),c=2.9760(6)nm,α=β=90,γ=120°,V=10.240(3)nm^(3),Z=3,A,aclcd=1.564 g/cm^(3),F(000)=4908.1 is composed of one{[Na(B18-C-6)]_(6)[Pt(SCN)_(6)]}4+complex cation,one[Pt(SCN)_(6)]^(2-)complex anion and two SCN~anions.{[Na(B18-C-6)]_(6)[Pt(SCN)_(6)3}4+complex cation shows a three-dimensional network structure bridged by Na-O interactions between adjacent[Na(B18-C-6)]+units.The function of[Pt(SCN)_(6)]^(2-)complex anion and two SCN'anions are balancing charge in crystal.展开更多
Electrically anisotropic strata are abundant in nature, so their study can help our data interpretation and our understanding of the processes of geodynamics. However, current data processing generally assumes isotrop...Electrically anisotropic strata are abundant in nature, so their study can help our data interpretation and our understanding of the processes of geodynamics. However, current data processing generally assumes isotropic conditions when surveying anisotropic structures, which may cause discrepancies between reality and electromagnetic data interpretation. Moreover, the anisotropic interpretation of the time-domain airborne electromagnetic （TDAEM） method is still confined to one dimensional （1D） cases, and the corresponding three-dimensional （3D） numerical simulations are still in development. In this study, we expanded the 3D TDAEM modeling of arbitrarily anisotropic media. First, through coordinate rotation of isotropic conductivity, we obtained the conductivity tensor of an arbitrary anisotropic rock. Next, we incorporated this into Maxwell＇s equations, using a regular hexahedral grid of vector finite elements to subdivide the solution area. A direct solver software package provided the solution for the sparse linear equations that resulted. Analytical solutions were used to verify the accuracy and feasibility of the algorithm. The proven model was then applied to analyze the effects of arbitrary anisotropy in 3D TDAEM via the distribution of responses and amplitude changes, which revealed that different anisotropy situations strongly affected the responses of TDAEM.展开更多
The mobility of the vectored thruster AUV in different environment is the important premise of control system design. The new type of autonomous underwater vehicle (AUV) equipped with rudders and vectored thrusters wh...The mobility of the vectored thruster AUV in different environment is the important premise of control system design. The new type of autonomous underwater vehicle (AUV) equipped with rudders and vectored thrusters which are combined to control the course is studied. Firstly, Euler angles representation and quaternion method are applied to establish six-DOF kinematic model respectively, then Newton second law and Lagrangian approach are used to deduce the vectored thruster AUV’s nonlinear dynamic equations with six degrees of freedom (DOF) respectively in complex sea conditions based on the random wave theory according to the structural and kinetic characteristics of the vectored thruster AUV in this paper. The kinematic models and dynamic models based on different theories have the same expression and conclusion, which shows that the kinematic models and dynamic models of the vectored thruster AUV are accurate. The Runge-Kutta arithmetic is used to solve the dynamic equations, which not only can simulate the motions such as cruise and hover but also can describe the vehicle’s low-frequency and high-frequency motion. The results of computation show that the mobility of the vectored thruster AUV in interference-free environment and the integrated signals including low-frequency motion signal and high-frequency motion signal in environmental disturbance accord with practical situation, which not only solve the problem of especial singularities when the pitch angle θ = ±90° but also clears up the difficulties of computation and display of the coupled nonlinear motion equations in complex sea conditions. Moreover, the high maneuverability of the vectored thruster AUV equipped with rudders and vectored thrusters is validated, which lays a foundation for the control system design.展开更多
Two kinds of contact problems, i.e., the frictional contact problem and the adhesive contact problem, in three-dimensional （3D） icosahedral quasicrystals are dis- cussed by a complex variable function method. For th...Two kinds of contact problems, i.e., the frictional contact problem and the adhesive contact problem, in three-dimensional （3D） icosahedral quasicrystals are dis- cussed by a complex variable function method. For the frictional contact problem, the contact stress exhibits power singularities at the edge of the contact zone. For the adhe- sive contact problem, the contact stress exhibits oscillatory singularities at the edge of the contact zone. The numerical examples show that for the two kinds of contact problems, the contact stress exhibits singularities, and reaches the maximum value at the edge of the contact zone. The phonon-phason coupling constant has a significant effect on the contact stress intensity, while has little impact on the contact stress distribution regu- lation. The results are consistent with those of the classical elastic materials when the phonon-phason coupling constant is 0. For the adhesive contact problem, the indentation force has positive correlation with the contact displacement, but the phonon-phason cou- pling constant impact is barely perceptible. The validity of the conclusions is verified.展开更多
By virtue of the comparability between the wave superposition method and the dynamic analysis of structures, a general format for overcoming the non-uniqueness of solution induced by the wave superposition method at t...By virtue of the comparability between the wave superposition method and the dynamic analysis of structures, a general format for overcoming the non-uniqueness of solution induced by the wave superposition method at the eigenfrequencies of the corresponding interior problems is proposed. By adding appropriate damp to the virtual source system of the wave superposition method, the unique solutions for all wave numbers can be ensured. Based on this thought, a novel method-wave superposition method with complex radius vector is constructed. Not only is the computational time of this method approximately equal to that of the standard wave superposition method, but also the accuracy is much higher compared with other correlative methods. Finally, by taking the pulsating sphere and oscillating sphere as examples, the results of calculation show that the present method can effectively overcome the non-uniqueness problem.展开更多
Objective:The aim of the study was to evaluate three-dimensional virtual models(3DVMs)usefulness in the intraoperative assistance of minimally-invasive partial nephrectomy in highly complex renal tumors.Methods:At our...Objective:The aim of the study was to evaluate three-dimensional virtual models(3DVMs)usefulness in the intraoperative assistance of minimally-invasive partial nephrectomy in highly complex renal tumors.Methods:At our institution cT1-2N0M0 all renal masses with Preoperative Aspects and Dimensions Used for an Anatomical classification score≥10 treated with minimally-invasive partial nephrectomy were considered for the present study.For inclusion a baseline contrast-enhanced computed tomography in order to obtain 3DVMs,the baseline and postoperative serum creatinine as well as estimated glomerular filtration rate values were needed.These patients,in which 3DVMs were used to assist the surgeon in the planning and intraoperative guidance,were then compared with a control group of patients who underwent minimally-invasive partial nephrectomy with the same renal function assessments,but without 3DVMs.Multivariable logistic regression models were used to predict the margin,ischemia,and complication score achievement.Results:Overall,79 patients met the inclusion criteria and were compared with 143 complex renal masses without 3DVM assistance.The 3DVM group showed better postoperative outcomes in terms of baseline-weighted differential estimated glomerular filtration rate(-17.7%vs.-22.2%,p=0.03),postoperative complications(16.5%vs.23.1%,p=0.03),and major complications(Clavien Dindo>III,2.5%vs.5.6%,p=0.03).At multivariable logistic regression 3DVM assistance independently predicted higher rates of successful partial nephrectomy(odds ratio:1.42,p=0.03).Conclusion:3DVMs represent a useful tool to plan a tailored surgical approach in case of surgically complex masses.They can be used in different ways,matching the surgeon's needs from the planning phase to the demolitive and reconstructive phase,leading towards maximum safety and efficacy outcomes.展开更多
Using the twin shear stress yield criterion, the surface integral of the co-line vectors, and the integration depending on upper limit, Kobayashi＇s three-dimensional velocity field of rolling was analyzed and an anal...Using the twin shear stress yield criterion, the surface integral of the co-line vectors, and the integration depending on upper limit, Kobayashi＇s three-dimensional velocity field of rolling was analyzed and an analytical expression of rolling torque and single force was obtained. Through redoing the same experiment of rolling pure lead as Sims, the calculated results by the above expression were compared with those of Kobayashi and Sims formulae. The results show that the twin shear stress yield criterion is available for rolling analysis and the calculated results by the new formula are a little higher than those by Kobayashi and Sims ones if the reduction ratio is less than 30%.展开更多
Currently, for some complex plastic deformations, the analytical solution can not be obtained by using Mises yield criterion, because Mises yield criterion is nine dimensions, the velocity field is complex, and the so...Currently, for some complex plastic deformations, the analytical solution can not be obtained by using Mises yield criterion, because Mises yield criterion is nine dimensions, the velocity field is complex, and the solving methods are not innovative. Corresponding solutions of these problems are that yield criterion is linearized to reduce the variable numbers, and the velocity field and the solving methods are reasonably simplified, respectively. In this paper, a new linear yield criterion--mean yield（MY） criterion and inner-product of strain rate vector are used to analytically solve 3D forging taking into account bugling of sides. The velocity field is expressed as a vector in three dimensions, and rotation and divergence are applied to confirm that the velocity field is kinematically admissible. Then, the corresponding strain rate tensor of the velocity field is transformed into principal one by making the determinant of coefficients of the tensor cubic equation be zero. By using MY criterion, the plastic power is term by term integrated and summed according to inner-product of strain rate vector. An upper bound analytical solution is obtained for the forging, and verified by a pure lead press test. The test result turns out that the total pressure calculated by MY criterion is higher by 2.5%-15% than measuring value. In addition, a measuring formula of bulging parameter （a） is proposed, but the values of a measured by the formula are lower than those optimized by the golden section search. The total pressure calculated by MY criterion is compared with the ones by twin shear, Trasca yield, and Mises yield criterion. The comparing result shows that the total pressure calculated by MY criterion is slightly higher than the mean value of that by twin shear and Trasca yield criterion, and lower than that by Mises yield criterion, but more close to that by Mises yield criterion compared with that by other two. The proposed analytical solving methods can be effectively used to other complex plastic deformation, simplifying the solving process and obtaining the reasonable results.展开更多
Nowadays, power quality issues are becoming a significant research topic because of the increasing inclusion of very sensitive devices and considerable renewable energy sources. In general, most of the previous power ...Nowadays, power quality issues are becoming a significant research topic because of the increasing inclusion of very sensitive devices and considerable renewable energy sources. In general, most of the previous power quality classification techniques focused on single power quality events and did not include an optimal feature selection process. This paper presents a classification system that employs Wavelet Transform and the RMS profile to extract the main features of the measured waveforms containing either single or complex disturbances. A data mining process is designed to select the optimal set of features that better describes each disturbance present in the waveform. Support Vector Machine binary classifiers organized in a “One Vs Rest” architecture are individually optimized to classify single and complex disturbances. The parameters that rule the performance of each binary classifier are also individually adjusted using a grid search algorithm that helps them achieve optimal performance. This specialized process significantly improves the total classification accuracy. Several single and complex disturbances were simulated in order to train and test the algorithm. The results show that the classifier is capable of identifying >99% of single disturbances and >97% of complex disturbances.展开更多
Orbital angular momentum(OAM),emerging as an inherently high-dimensional property of photons,has boosted information capacity in optical communications.However,the potential of OAM in optical computing remains almost ...Orbital angular momentum(OAM),emerging as an inherently high-dimensional property of photons,has boosted information capacity in optical communications.However,the potential of OAM in optical computing remains almost unexplored.Here,we present a highly efficient optical computing protocol for complex vector convolution with the superposition of high-dimensional OAM eigenmodes.We used two cascaded spatial light modulators to prepare suitable OAM superpositions to encode two complex vectors.Then,a deep-learning strategy is devised to decode the complex OAM spectrum,thus accomplishing the optical convolution task.In our experiment,we succeed in demonstrating 7-,9-,and 11-dimensional complex vector convolutions,in which an average proximity better than 95%and a mean relative error<6%are achieved.Our present scheme can be extended to incorporate other degrees of freedom for a more versatile optical computing in the high-dimensional Hilbert space.展开更多
The electromagnetic scattering computation has developed rapidly for many years; some computing problems for complex and coated targets cannot be solved by using the existing theory and computing models. A computing m...The electromagnetic scattering computation has developed rapidly for many years; some computing problems for complex and coated targets cannot be solved by using the existing theory and computing models. A computing model based on data is established for making up the insufficiency of theoretic models. Based on the ＂support vector regression method＂, which is formulated on the principle of minimizing a structural risk, a data model to predicate the unknown radar cross section of some appointed targets is given. Comparison between the actual data and the results of this predicting model based on support vector regression method proved that the support vector regression method is workable and with a comparative precision.展开更多
To investigate the long-term stability of deep rocks,a three-dimensional(3D)time-dependent model that accounts for excavation-induced damage and complex stress state is developed.This model comprises three main compon...To investigate the long-term stability of deep rocks,a three-dimensional(3D)time-dependent model that accounts for excavation-induced damage and complex stress state is developed.This model comprises three main components:a 3D viscoplastic isotropic constitutive relation that considers excavation damage and complex stress state,a quantitative relationship between critical irreversible deformation and complex stress state,and evolution characteristics of strength parameters.The proposed model is implemented in a self-developed numerical code,i.e.CASRock.The reliability of the model is validated through experiments.It is indicated that the time-dependent fracturing potential index(xTFPI)at a given time during the attenuation creep stage shows a negative correlation with the extent of excavationinduced damage.The time-dependent fracturing process of rock demonstrates a distinct interval effect of the intermediate principal stress,thereby highlighting the 3D stress-dependent characteristic of the model.Finally,the influence of excavation-induced damage and intermediate principal stress on the time-dependent fracturing characteristics of the surrounding rocks around the tunnel is discussed.展开更多
New objects characterizing the structure of complex linear transformations areintroduced. These new objects yield a new result for the decomposition of complexvector spaces relative to complex lrnear transformations a...New objects characterizing the structure of complex linear transformations areintroduced. These new objects yield a new result for the decomposition of complexvector spaces relative to complex lrnear transformations and provide all Jordan basesby which the Jordan canonical form is constructed. Accordingly, they can result in thecelebrated Jordan theorem and the third decomposition theorem of space directly. and,moreover, they can give a new deep insight into the exquisite and subtle structure ofthe Jordan form. The latter indicates that the Jordan canonical form of a complexlinear transformation is an invariant structure associated with double arbitrary. choices.展开更多
In this paper,we investigate some properties of dual complex numbers,dual complex vectors,and dual complex matrices.First,based on the magnitude of the dual complex number,we study the Young inequality,the Hölder...In this paper,we investigate some properties of dual complex numbers,dual complex vectors,and dual complex matrices.First,based on the magnitude of the dual complex number,we study the Young inequality,the Hölder inequality,and the Minkowski inequality in the setting of dual complex numbers.Second,we define the p-norm of a dual complex vector,which is a nonnegative dual number,and show some related properties.Third,we study the properties of eigenvalues of unitary matrices and unitary triangulation of arbitrary dual complex matrices.In particular,we introduce the operator norm of dual complex matrices induced by the p-norm of dual complex vectors,and give expressions of three important operator norms of dual complex matrices.展开更多
基金Supported by the Health Commission of Fuyang City,Anhui,China,No.FY2023-45Fuyang Municipal Science and Technology Bureau,Anhui,China,No.FK20245505+1 种基金Anhui Provincial Health Commission,No.AHWJ2023Baa20164Bengbu Medical University,No.2023byzd215.
文摘BACKGROUND Sigmoid colon cancer faces challenges due to anatomical diversity,including variable inferior mesenteric artery(IMA)branching and tumor localization complexities,which increase intraoperative risks.AIM To comprehensively evaluate the impact of three-dimensional(3D)visualization technology on enhancing surgical precision and safety,as well as optimizing perioperative outcomes in laparoscopic sigmoid cancer resection.METHODS A prospective cohort of 106 patients(January 2023 to December 2024)undergoing laparoscopic sigmoid cancer resection was divided into the 3D(n=55)group and the control(n=51)group.The 3D group underwent preoperative enhanced computed tomography reconstruction(3D Slicer 5.2.2&Mimics 19.0).3D reconstruction visualization navigation intraoperatively guided the following key steps:Tumor location,Toldt’s space dissection,IMA ligation level selection,regional lymph node dissection,and marginal artery preservation.Outcomes included operative parameters,lymph node yield,and recovery metrics.RESULTS The 3D group demonstrated a significantly shorter operative time(172.91±20.69 minutes vs 190.29±32.29 minutes;P=0.002),reduced blood loss(31.5±11.8 mL vs 44.1±23.4 mL,P=0.001),earlier postoperative flatus(2.23±0.54 days vs 2.53±0.61 days;P=0.013),shorter hospital length of stay(13.47±1.74 days vs 16.20±7.71 days;P=0.013),shorter postoperative length of stay(8.6±2.6 days vs 10.5±4.9 days;P=0.014),and earlier postoperative exhaust time(2.23±0.54 days vs 2.53±0.61 days;P=0.013).Furthermore,the 3D group exhibited a higher mean number of lymph nodes harvested(16.91±5.74 vs 14.45±5.66;P=0.030).CONCLUSION The 3D visualization technology effectively addresses sigmoid colon anatomical complexity through surgical navigation,improving procedural safety and efficiency.
文摘A new type of implantable drug delivery devices （ DDD ） with complicated architectures were fubricated by three-dimensional printing technique, employing levofloxacin （LVFX） as a model drug. Processing parameters were optimized in riew of the layer thickness, spucing between printed lines, flow rate of liquid binder and the fast axis speed. The prepared DDD prototype consists of a double-layer structure, of which the upper region is a reservoir system and the lower region is a matrix one. The in vitro release test revealed that LVFX was released in a dual-puse pattern. This DDD may present a new strategy for the prophylaxis and treatment of diseases such as bone infection in the near future.
基金supported by the Ministry of Science and Technology of China (2010DFA32680)the National Natural Science Foundation of China (21005062)the Fundamental Research Funds for the Central Universities (CDJRC10220010)
文摘Three-dimensional holographic vector of atomic interaction field（3D-HoVAIF） is used to describe the chemical structures of polychlorinated naphthalenes（PCNs）.After variable screening by stepwise multiple regression（SMR） technique,the liner relationships between gas-chromatographic relative retention time（RRT）,298 K supercooled liquid pressures（logPL）,n-octanol/air partition coefficient（logKOA）,n-octanol/water partition coefficient（logKOW）,aqueous solubilities（logSW）,relative in vitro potency values（-logEROD） of PCNs and 3D-HoVAIF descriptors have been established by partial least-square（PLS） regression.The result shows that the 3D-HoVAIF descriptors can be well used to express the quantitative structure-property（activity） relationships of PCNs.Predictive capability of the models has also been demonstrated by leave-one-out cross-validation.Moreover,the predicted values have been presented for those PCNs which are lack of experimentally physico-chemical properties and biological activity by the optimum models.
基金This work was supported by the National Natural Science Foundation of China (No. 50572040)
文摘The title complex Mn（H2O）2（HNic）2 （C22H12MnN2O8, Mr = 367.18） crystallizes in monoclinic, space group P21/c with a = 7.5735（8）, b = 12.5295（13）, c = 7.6466（8）A.β = 101.2790（10）°, Z = 2, V= 711.59（13） A^3, D, = 1.714 g/cm^3,μ（MoKa） = 0.974 mm^-1, F（000） = 374, R1 （1255 observed reflections （Ⅰ 〉 2σ（Ⅰ）） = 0.0250） and wR2 = 0.0662 （all data）. In this paper, we report the complexation of Mn（Ⅱ） by the bidentate ligand 2-hydroxynicotinic acid （HNic）. In the crystal the Mn（Ⅱ） ion exhibits a deformed octahedron structure. The title complex Mn（H2O）2（HNic）2 has a three-dimensional （3D） network structure extended by hydrogen bonds, which are formed by two typical eight-membered hydrogen-bonded rings.
基金Project supported by the Grants-in-Aid for Scientific Research from the Ministry of Education, Science and Culture, Japan andin Part by the Inter-University Joint Research Program for the Common Use of JAERI (Japan Atomic Energy Research Institute)Facilities
文摘Some functional lanthanide metal complexes, such as acetylacetonato complexes, ethylenediaminetetraacetato complexes, were successfully applied for diagnostic technique. The authors are interested in investigating the structure and bonding in lanthanide and actinide metal complexes using 166Er, t55Gd, and 237Np Mtissbauer spectroscopies in connection with single-crystal and/or powder X-ray diffraction, making clear the differences on their structures as well as the differences in the participation of 4f and 5f orbitals in the chemical bonds. In this article, the crystal structures of two novel Gd（Ⅲ） acetylacetonato complexes, Gd（pta）3 · 2H2O （pta = 1,1,1 -trifluoro-5,5-dimethy 1-2,4-hexanedione） and Gd（bfa）3 · 2H2O （bfa = 1, 1, 1 -trifluoro-4-phenyl-2-4-butanedione） were reported. Though both of them were dihydrate and had distorted square antiprismatical structure, Gd（pta）3 · 2H2O crystallizes in the P 2 1/n （#14） monoclinic space group and its lattice parameters are a = 1.4141（6） nm, b = 1.0708（3） nm, c =2.2344（4） nm, β =952.4（2）°, and Gd（bfa）3· 2H2O crystallizes in P 212121 orthorhombic space group and its lattice parameters were a = 1.322 （1） nm, b = 2.295 （1） nm, c = 1. 0786（8） nm. In the meantime, the authors had finished a systematic investigation on the ^155Gd Mossbauer isomer shift （δ） of various Gd（Ⅲ） metal complexes having a different coordination number （C.N.） and different ratios coordinating oxygen to nitrogen. A tendency for the 6 value to decrease with an increase in the C.N, and the number of the nitrogen atom coordinating to Gd was confirmed. This indicated that the Gd-O and/or Gd-N bond in the investigated Gd（Ⅲ） metal complexes had a small covalent contribution, which was possible to be deduced from the O and/or N atoms of the lisands donating electrons to 6s, 5d, and 4f orbitals of Gd.
文摘Our purpose in this study was to develop an automated method for measuring three-dimensional (3D) cerebral cortical thicknesses in patients with Alzheimer’s disease (AD) using magnetic resonance (MR) images. Our proposed method consists of mainly three steps. First, a brain parenchymal region was segmented based on brain model matching. Second, a 3D fuzzy membership map for a cerebral cortical region was created by applying a fuzzy c-means (FCM) clustering algorithm to T1-weighted MR images. Third, cerebral cortical thickness was three- dimensionally measured on each cortical surface voxel by using a localized gradient vector trajectory in a fuzzy membership map. Spherical models with 3 mm artificial cortical regions, which were produced using three noise levels of 2%, 5%, and 10%, were employed to evaluate the proposed method. We also applied the proposed method to T1-weighted images obtained from 20 cases, i.e., 10 clinically diagnosed AD cases and 10 clinically normal (CN) subjects. The thicknesses of the 3 mm artificial cortical regions for spherical models with noise levels of 2%, 5%, and 10% were measured by the proposed method as 2.953 ± 0.342, 2.953 ± 0.342 and 2.952 ± 0.343 mm, respectively. Thus the mean thicknesses for the entire cerebral lobar region were 3.1 ± 0.4 mm for AD patients and 3.3 ± 0.4 mm for CN subjects, respectively (p < 0.05). The proposed method could be feasible for measuring the 3D cerebral cortical thickness on individual cortical surface voxels as an atrophy feature in AD.
文摘The novel benzo-18-crown-6(B18-C-6)complex;{[Na(Bl8-C-6)]_(6)[Pt(SCN)_(6)]}[Pt(SCN)_(6)](SCN)_(2)(1)was synthesized and characterized by elemental analysis,IR spectrum and x-ray diffraction analysis.Thr crystal structure belongs to rhomobohedral,space group R-3 with cell dimesions:a=6=1.9933(3),c=2.9760(6)nm,α=β=90,γ=120°,V=10.240(3)nm^(3),Z=3,A,aclcd=1.564 g/cm^(3),F(000)=4908.1 is composed of one{[Na(B18-C-6)]_(6)[Pt(SCN)_(6)]}4+complex cation,one[Pt(SCN)_(6)]^(2-)complex anion and two SCN~anions.{[Na(B18-C-6)]_(6)[Pt(SCN)_(6)3}4+complex cation shows a three-dimensional network structure bridged by Na-O interactions between adjacent[Na(B18-C-6)]+units.The function of[Pt(SCN)_(6)]^(2-)complex anion and two SCN'anions are balancing charge in crystal.
基金financially supported by National Nonprofit institute Research Grant of IGGE(Nos.AS2017J06,AS2017Y04,and AS2016J10)Survey on coastal area for airborne magnetic method of UNV in Jiangsu(No.DD20160151-03)+3 种基金Key National Research Project of China(No.2017YFC0601900)Key Program of National Natural Science Foundation of China(No.41530320)Natural Science Foundation(No.41274121)China Natural Science Foundation for Young Scientists(No.41404093)
文摘Electrically anisotropic strata are abundant in nature, so their study can help our data interpretation and our understanding of the processes of geodynamics. However, current data processing generally assumes isotropic conditions when surveying anisotropic structures, which may cause discrepancies between reality and electromagnetic data interpretation. Moreover, the anisotropic interpretation of the time-domain airborne electromagnetic （TDAEM） method is still confined to one dimensional （1D） cases, and the corresponding three-dimensional （3D） numerical simulations are still in development. In this study, we expanded the 3D TDAEM modeling of arbitrarily anisotropic media. First, through coordinate rotation of isotropic conductivity, we obtained the conductivity tensor of an arbitrary anisotropic rock. Next, we incorporated this into Maxwell＇s equations, using a regular hexahedral grid of vector finite elements to subdivide the solution area. A direct solver software package provided the solution for the sparse linear equations that resulted. Analytical solutions were used to verify the accuracy and feasibility of the algorithm. The proven model was then applied to analyze the effects of arbitrary anisotropy in 3D TDAEM via the distribution of responses and amplitude changes, which revealed that different anisotropy situations strongly affected the responses of TDAEM.
基金supported by National Hi-tech Research and Development Program of China(863 Program, Grant No. 2006AA09Z235)Hunan Provincial Innovation Foundation For Postgraduate of China(Grant No. CX2009B003)
文摘The mobility of the vectored thruster AUV in different environment is the important premise of control system design. The new type of autonomous underwater vehicle (AUV) equipped with rudders and vectored thrusters which are combined to control the course is studied. Firstly, Euler angles representation and quaternion method are applied to establish six-DOF kinematic model respectively, then Newton second law and Lagrangian approach are used to deduce the vectored thruster AUV’s nonlinear dynamic equations with six degrees of freedom (DOF) respectively in complex sea conditions based on the random wave theory according to the structural and kinetic characteristics of the vectored thruster AUV in this paper. The kinematic models and dynamic models based on different theories have the same expression and conclusion, which shows that the kinematic models and dynamic models of the vectored thruster AUV are accurate. The Runge-Kutta arithmetic is used to solve the dynamic equations, which not only can simulate the motions such as cruise and hover but also can describe the vehicle’s low-frequency and high-frequency motion. The results of computation show that the mobility of the vectored thruster AUV in interference-free environment and the integrated signals including low-frequency motion signal and high-frequency motion signal in environmental disturbance accord with practical situation, which not only solve the problem of especial singularities when the pitch angle θ = ±90° but also clears up the difficulties of computation and display of the coupled nonlinear motion equations in complex sea conditions. Moreover, the high maneuverability of the vectored thruster AUV equipped with rudders and vectored thrusters is validated, which lays a foundation for the control system design.
基金supported by the National Natural Science Foundation of China(Nos.11362018,11261045,and 11261401)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20116401110002)
文摘Two kinds of contact problems, i.e., the frictional contact problem and the adhesive contact problem, in three-dimensional （3D） icosahedral quasicrystals are dis- cussed by a complex variable function method. For the frictional contact problem, the contact stress exhibits power singularities at the edge of the contact zone. For the adhe- sive contact problem, the contact stress exhibits oscillatory singularities at the edge of the contact zone. The numerical examples show that for the two kinds of contact problems, the contact stress exhibits singularities, and reaches the maximum value at the edge of the contact zone. The phonon-phason coupling constant has a significant effect on the contact stress intensity, while has little impact on the contact stress distribution regu- lation. The results are consistent with those of the classical elastic materials when the phonon-phason coupling constant is 0. For the adhesive contact problem, the indentation force has positive correlation with the contact displacement, but the phonon-phason cou- pling constant impact is barely perceptible. The validity of the conclusions is verified.
基金Project supported by the National Natural Science Foundation of China (No. 10172038).
文摘By virtue of the comparability between the wave superposition method and the dynamic analysis of structures, a general format for overcoming the non-uniqueness of solution induced by the wave superposition method at the eigenfrequencies of the corresponding interior problems is proposed. By adding appropriate damp to the virtual source system of the wave superposition method, the unique solutions for all wave numbers can be ensured. Based on this thought, a novel method-wave superposition method with complex radius vector is constructed. Not only is the computational time of this method approximately equal to that of the standard wave superposition method, but also the accuracy is much higher compared with other correlative methods. Finally, by taking the pulsating sphere and oscillating sphere as examples, the results of calculation show that the present method can effectively overcome the non-uniqueness problem.
文摘Objective:The aim of the study was to evaluate three-dimensional virtual models(3DVMs)usefulness in the intraoperative assistance of minimally-invasive partial nephrectomy in highly complex renal tumors.Methods:At our institution cT1-2N0M0 all renal masses with Preoperative Aspects and Dimensions Used for an Anatomical classification score≥10 treated with minimally-invasive partial nephrectomy were considered for the present study.For inclusion a baseline contrast-enhanced computed tomography in order to obtain 3DVMs,the baseline and postoperative serum creatinine as well as estimated glomerular filtration rate values were needed.These patients,in which 3DVMs were used to assist the surgeon in the planning and intraoperative guidance,were then compared with a control group of patients who underwent minimally-invasive partial nephrectomy with the same renal function assessments,but without 3DVMs.Multivariable logistic regression models were used to predict the margin,ischemia,and complication score achievement.Results:Overall,79 patients met the inclusion criteria and were compared with 143 complex renal masses without 3DVM assistance.The 3DVM group showed better postoperative outcomes in terms of baseline-weighted differential estimated glomerular filtration rate(-17.7%vs.-22.2%,p=0.03),postoperative complications(16.5%vs.23.1%,p=0.03),and major complications(Clavien Dindo>III,2.5%vs.5.6%,p=0.03).At multivariable logistic regression 3DVM assistance independently predicted higher rates of successful partial nephrectomy(odds ratio:1.42,p=0.03).Conclusion:3DVMs represent a useful tool to plan a tailored surgical approach in case of surgically complex masses.They can be used in different ways,matching the surgeon's needs from the planning phase to the demolitive and reconstructive phase,leading towards maximum safety and efficacy outcomes.
基金ItemSponsored by National Natural Science Foundation of China (50474015)
文摘Using the twin shear stress yield criterion, the surface integral of the co-line vectors, and the integration depending on upper limit, Kobayashi＇s three-dimensional velocity field of rolling was analyzed and an analytical expression of rolling torque and single force was obtained. Through redoing the same experiment of rolling pure lead as Sims, the calculated results by the above expression were compared with those of Kobayashi and Sims formulae. The results show that the twin shear stress yield criterion is available for rolling analysis and the calculated results by the new formula are a little higher than those by Kobayashi and Sims ones if the reduction ratio is less than 30%.
基金supported by National Natural Science Foundation of China (Grant No. 50474015)State Key Laboratory of Rolling and Automation(RAL) Self-determination Science Foundation of UK (Grant No. RAL_SD_2008_2)
文摘Currently, for some complex plastic deformations, the analytical solution can not be obtained by using Mises yield criterion, because Mises yield criterion is nine dimensions, the velocity field is complex, and the solving methods are not innovative. Corresponding solutions of these problems are that yield criterion is linearized to reduce the variable numbers, and the velocity field and the solving methods are reasonably simplified, respectively. In this paper, a new linear yield criterion--mean yield（MY） criterion and inner-product of strain rate vector are used to analytically solve 3D forging taking into account bugling of sides. The velocity field is expressed as a vector in three dimensions, and rotation and divergence are applied to confirm that the velocity field is kinematically admissible. Then, the corresponding strain rate tensor of the velocity field is transformed into principal one by making the determinant of coefficients of the tensor cubic equation be zero. By using MY criterion, the plastic power is term by term integrated and summed according to inner-product of strain rate vector. An upper bound analytical solution is obtained for the forging, and verified by a pure lead press test. The test result turns out that the total pressure calculated by MY criterion is higher by 2.5%-15% than measuring value. In addition, a measuring formula of bulging parameter （a） is proposed, but the values of a measured by the formula are lower than those optimized by the golden section search. The total pressure calculated by MY criterion is compared with the ones by twin shear, Trasca yield, and Mises yield criterion. The comparing result shows that the total pressure calculated by MY criterion is slightly higher than the mean value of that by twin shear and Trasca yield criterion, and lower than that by Mises yield criterion, but more close to that by Mises yield criterion compared with that by other two. The proposed analytical solving methods can be effectively used to other complex plastic deformation, simplifying the solving process and obtaining the reasonable results.
文摘Nowadays, power quality issues are becoming a significant research topic because of the increasing inclusion of very sensitive devices and considerable renewable energy sources. In general, most of the previous power quality classification techniques focused on single power quality events and did not include an optimal feature selection process. This paper presents a classification system that employs Wavelet Transform and the RMS profile to extract the main features of the measured waveforms containing either single or complex disturbances. A data mining process is designed to select the optimal set of features that better describes each disturbance present in the waveform. Support Vector Machine binary classifiers organized in a “One Vs Rest” architecture are individually optimized to classify single and complex disturbances. The parameters that rule the performance of each binary classifier are also individually adjusted using a grid search algorithm that helps them achieve optimal performance. This specialized process significantly improves the total classification accuracy. Several single and complex disturbances were simulated in order to train and test the algorithm. The results show that the classifier is capable of identifying >99% of single disturbances and >97% of complex disturbances.
基金supported by the National Natural Science Foundation of China(Grant Nos.12034016,61975169,and 11904303)the Youth Innovation Fund of Xiamen(Grant No.3502Z20206045)+2 种基金the Fundamental Research Funds for the Central Universities at Xiamen University(Grant Nos.20720200074 and 20720220030)the Natural Science Foundation of Fujian Province of China(Grant No.2021J02002)and for Distinguished Young Scientists(Grant No.2015J06002)the Program for New Century Excellent Talents in University of China(Grant No.NCET-13-0495).
文摘Orbital angular momentum(OAM),emerging as an inherently high-dimensional property of photons,has boosted information capacity in optical communications.However,the potential of OAM in optical computing remains almost unexplored.Here,we present a highly efficient optical computing protocol for complex vector convolution with the superposition of high-dimensional OAM eigenmodes.We used two cascaded spatial light modulators to prepare suitable OAM superpositions to encode two complex vectors.Then,a deep-learning strategy is devised to decode the complex OAM spectrum,thus accomplishing the optical convolution task.In our experiment,we succeed in demonstrating 7-,9-,and 11-dimensional complex vector convolutions,in which an average proximity better than 95%and a mean relative error<6%are achieved.Our present scheme can be extended to incorporate other degrees of freedom for a more versatile optical computing in the high-dimensional Hilbert space.
文摘The electromagnetic scattering computation has developed rapidly for many years; some computing problems for complex and coated targets cannot be solved by using the existing theory and computing models. A computing model based on data is established for making up the insufficiency of theoretic models. Based on the ＂support vector regression method＂, which is formulated on the principle of minimizing a structural risk, a data model to predicate the unknown radar cross section of some appointed targets is given. Comparison between the actual data and the results of this predicting model based on support vector regression method proved that the support vector regression method is workable and with a comparative precision.
基金supported by the National Natural Science Foundation of China(Grant No.52125903)the China Postdoctoral Science Foundation(Grant No.2023M730367)the Fundamental Research Funds for Central Public Welfare Research Institutes of China(Grant No.CKSF2023323/YT).
文摘To investigate the long-term stability of deep rocks,a three-dimensional(3D)time-dependent model that accounts for excavation-induced damage and complex stress state is developed.This model comprises three main components:a 3D viscoplastic isotropic constitutive relation that considers excavation damage and complex stress state,a quantitative relationship between critical irreversible deformation and complex stress state,and evolution characteristics of strength parameters.The proposed model is implemented in a self-developed numerical code,i.e.CASRock.The reliability of the model is validated through experiments.It is indicated that the time-dependent fracturing potential index(xTFPI)at a given time during the attenuation creep stage shows a negative correlation with the extent of excavationinduced damage.The time-dependent fracturing process of rock demonstrates a distinct interval effect of the intermediate principal stress,thereby highlighting the 3D stress-dependent characteristic of the model.Finally,the influence of excavation-induced damage and intermediate principal stress on the time-dependent fracturing characteristics of the surrounding rocks around the tunnel is discussed.
文摘New objects characterizing the structure of complex linear transformations areintroduced. These new objects yield a new result for the decomposition of complexvector spaces relative to complex lrnear transformations and provide all Jordan basesby which the Jordan canonical form is constructed. Accordingly, they can result in thecelebrated Jordan theorem and the third decomposition theorem of space directly. and,moreover, they can give a new deep insight into the exquisite and subtle structure ofthe Jordan form. The latter indicates that the Jordan canonical form of a complexlinear transformation is an invariant structure associated with double arbitrary. choices.
基金the National Natural Science Foundation of China(Grant No.11871051).
文摘In this paper,we investigate some properties of dual complex numbers,dual complex vectors,and dual complex matrices.First,based on the magnitude of the dual complex number,we study the Young inequality,the Hölder inequality,and the Minkowski inequality in the setting of dual complex numbers.Second,we define the p-norm of a dual complex vector,which is a nonnegative dual number,and show some related properties.Third,we study the properties of eigenvalues of unitary matrices and unitary triangulation of arbitrary dual complex matrices.In particular,we introduce the operator norm of dual complex matrices induced by the p-norm of dual complex vectors,and give expressions of three important operator norms of dual complex matrices.
