Two-dimensional dumbbell silicene as a promising anode material for(Li/Na/K)-ion batteries

Rechargeable ion batteries require anode materials with excellent performance,presenting a key challenge for researchers.This paper explores the potential of using two-dimensional dumbbell silicene as an anode material for alkali metal ion batteries through density functional theory(DFT)calculations.Our findings demonstrate that alkali metal ions have negative adsorption energies on dumbbell silicene,and the energy barriers for Li/Na/K ion diffusion are as low as0.032 e V/0.055 e V/0.21 e V,indicating that metal ions can easily diffuse across the entire surface of dumbbell silicene.Additionally,the average open circuit voltages of dumbbell silicene as anode for Li-ion,Na-ion,and K-ion batteries are 0.42 V,0.41 V,and 0.60 V,respectively,with corresponding storage capacities of 716 m Ah/g,622 m Ah/g,and 716 m Ah/g.These results suggest that dumbbell silicene is an ideal anode material for Li-ion,Na-ion,and K-ion batteries,with high capacity,low open circuit voltage,and high ion diffusion kinetics.Moreover,our calculations show that the theoretical capacities obtained using DFT-D2 are higher than those obtained using DFT-D3,providing a valuable reference for subsequent theoretical calculations.

Bilateral and symmetric C1-C2 dumbbell ganglioneuromas associated with neurofibromatosis type 1: A case report

BACKGROUND Ganglioneuroma(GN) is a rare and benign tumor that originates from autonomic nervous system ganglion cells. The most frequently involved sites are the posterior mediastinum, the abdominal cavity, and the retroperitoneal space. It rarely occurs in the cervical area, compressing the spinal cord. Neurofibromatosis type 1(NF-1) is an autosomal dominant inheritance disorder, whose prevalence rate approximates one per 3000.CASE SUMMARY We report an extremely rare case of bilateral and symmetric dumbbell GNs of the cervical spine with NF-1. A 27-year-old man with NF-1 presented with a one-year history of gradually progressive right upper extremity weakness and numbness in both hands. Magnetic resonance imaging showed bilateral and symmetric dumbbell lesions at the C1-C2 levels compressing the spinal cord. We performed total resection of bilateral tumors, and the postoperative histopathological diagnosis of the resected mass was GN. After operation, the preoperative symptoms were gradually relieved without complications. To our knowledge,this is the sixth report of cervical bilateral dumbbell GNs.CONCLUSION In some cases, cervical bilateral dumbbell GNs could be associated with NF-1.The exact diagnosis cannot be obtained before operation, and pathological outcome is the current gold standard. Surgical resection is the most effective option, and disease outcome is generally good after treatment.

Bone and soft tissue tumors presenting as sciatic notch dumbbell masses: A critical differential diagnosis of sciatica

AIM To study the clinical findings and characteristic features in sciatic notch dumbbell tumors(SNDTs).METHODS We retrospectively reviewed the clinical outcomes and characteristic features of consecutive cases of SNDTs(n = 8). RESULTS Buttock masses occurred in three patients with SNDT(37.5%). Severe buttock tenderness and pain at rest were observed in seven patients with SNDTs(87.5%). Remarkably, none of the patients with SNDTs experienced back pain. Mean tumor size was 8.4 ± 2.0 cm(range, 3.9 to 10.6 cm) and part of the tumor mass was detected in 2 patients in the sagittal view of lumbar magnetic resonance imaging(MRI).CONCLUSION The clinical information regarding to SNDTs is scarce. The authors consider that above mentioned characteristic findings may facilitate the suspicion of pelvic pathology and a search for SNDT by MRI or computed tomography should be considered in patients presenting with sciatica without evidence of spinal diseases.

Technical Innovation of Electrostimulation Biofeedback Combined with Vaginal Dumbbell in the Treatment of Postpartum Pelvic Floor Dysfunction

Objective: To investigate the application value of electrostimulation biofeedback therapy in combination with vaginal dumbbell therapy to postpartum pelvic floor dysfunction. Methods: Retrospective analysis of 200 cases of postpartum pelvic floor dysfunction patients discharged from the hospital from January 2016 to March 2019 as study subjects who were excluded other underlying diseases and were randomly divided into two groups of 100 cases per group, using electrostimulation biofeedback therapy combined vaginal dumbbell therapy as a treatment group. The treatment of electrostimulation biofeedback therapy in combination with kegel was treated as a control group. Then the curative effects of the two groups were compared and statistically analyzed. Results: There was no significant difference in EMG value of postpartum pelvic floor treatment, type I muscle strength, type II muscle strength, muscle type I fatigue, type II fatigue and POP-Q detection results between the two groups before treatment, p > 0.05. There were significant differences in type I muscle strength, type II muscle strength and muscle type I fatigue between the pelvic floor muscles and the muscles at the end of the treatment day, the sixth month and one year after treatment, p ?There was no statistically significant difference at?the end of muscle type II fatigue?treatment day, p > 0.05;while after the treatment of six months and one year, the difference was statistically significant, p 0.05. In addition, the treatment group and the control group were compared before and after treatment, the difference of myoelectric potential value, pelvic floor muscle type I muscle strength, type II muscle strength, muscle type I fatigue degree, type II fatigue degree and POP-Q test result were significant, and the changes in the indicators before and after treatment in the treatment group were significantly higher than the control group. Comparison of urinary incontinence between the two groups before and after treatment, the difference between pre-treatment and the end of treatment day was not statistically significant, p > 0.05;there was significant difference between half a year and one year after treatment (p 0.05, respectively). Comparing?the satisfaction with sexual life after the time of treatment day, half a year and one year after the end of treatment, the difference was statistically significant (p ?Conclusion: Electrical stimulation biofeedback therapy combined with vaginal dumbbell therapy has a good effect in the treatment of postpartum pelvic floor dysfunction, and it is worthy of popularization and application.

Lattice Boltzmann simulations of a dumbbell moving in a Poiseuille flow

In this paper, the lattice Boltzmann method is applied to simulate a dumbbell moving in a pressure-driven flow in a planar channel with the stress-integration method for the evaluation of hydrodynamic force acting on the cylinders. The simulation results show that the dumbbell also has the important feature of the Segr^-Silberberg effect like a particle in a Poiseuille flow. The dumbbell trajectories, orientations, the cylinders vertical velocities and angular velocities all reach their equilibrium values separately independent of their initial positions. It is also found that the dumbbell equilibrium positions depend on the flow Reynolds number, blockage ratio and elastic coefficient. This study is expected to be helpful to understand the dynamics of polymer solutions, polymer synthesis and reaction, etc.

A Rare Case of Cervical Dumbbell Meningioma with the C2 Spinous Process Preservation

Dumbbell growth is often observed in schwannoma but rarely in meningioma. In particular, the occurrence of dumbbell meningioma at the cervical cord level in Japan is markedly rare. We reported an elderly case with symptomatic meningioma that developed in a dumbbell shape from cervical spine and was treated successfully by surgery.

The surgical strategy of upper cervical dumbbell tumors

Objective To investigate the surgical strategy and prognosis of upper cervical dumbbell tumors.Methods From January 2001 to December 2009,46 consecutive cases with upper cervical dumbbell tumor were retrospec-tively studied on

Interfacial Activation of Catalytically Inert Au(6.7 nm)-Fe_(3)O_(4)Dumbbell Nanoparticles for CO Oxidation

Au nanoparticles epitaxially grown on Fe_(3)O_(4)in Au(6.7 nm)-Fe_(3)O_(4)dumbbell nanoparticles exhibit excellent stability against sintering,but display negligible catalytic activity in CO oxidation.Starting from various supported Au(6.7 nm)-Fe_(3)O_(4)catalysts prepared by the colloidal deposition method,we have unambiguously identifi ed the significance of the Au-TiO_(2)interface in CO oxidation,without any possible size effect of Au.In situ thermal decomposition of TiO_(2)precursors on Au-Fe_(3)O_(4)was found to be an effective way to increase the Au-TiO_(2)interface and thereby optimize the catalytic performance of TiO_(2)-supported Au-Fe_(3)O_(4)dumbbell nanoparticles.By reducing the size of Fe_(3)O_(4)from 15.2 to 4.9 nm,the Au-TiO_(2)contact was further increased so that the resulting TiO_(2)-supported Au(6.7 nm)-Fe_(3)O_(4)(4.9 nm)dumbbell particles become highly efficient catalysts for CO oxidation at room temperature.

Combined microneurosurgical and thoracoscopic resection for thoracic spine dumbbell tumors

Dumbbell tumors have both intraspinal and anterior paraspinal components connected through anintervertebral foramen. Most of these tumors are neurogenic and include schwannomas, neurofibromas, ganglioneuromas and neuroblastomas. 1.Fortunately, more than 90% of these tumors are benign.2. Dumbbell tumors of the thoracic spine are particularly difficult to expose and remove by virtue of their location and relationship with vital structures of the thoracic cavity. The traditional surgical approach for removing these tumors has been using either combined anterior thoracotomy and posterior neurosurgical procedures or the lateral extracavitary approach. We present our experience with resection of three dumbbell tumors with a combined microneurosurgical and thoracoscopic procedures in a single stage.

The FENE Dumbbell Model near Equilibrium

We study the global existence of smooth solutions near the equilibrium to a coupled microscopic-macroscopic FENE dumbbell model which arises from the kinetic theory of diluted solutions of polymeric liquids with noninteracting polymer chains.

Facile and diverse logic circuits based on dumbbell DNA-templated fluorescent copper nanoclusters and S1 nuclease detection

DNA-based logic gates promote the development of molecular computing and show enormous potential in the fields of nanotechnology and biotechnology. Dumbbell oligonucleotides(DNA) with poly-thymine(poly-T) loops and a nicked random double strand have been demonstrated to be an efficient template for the formation of fluorescent copper nanoclusters(Cu NCs) in our previous work. Herein, a new platform technology is presented with which to construct molecular logic gates by employing Cu NCs probe as a basic output generator, coupling of functional nucleases as the inputs. Two dumbbell DNAs are used with the difference in stem length(8 bp and 16 bp, respectively). The degradation of DNA templates can be tuned by various nucleic acid enzymes, single-stranded nuclease(S1), double-stranded specific nuclease(DSN), E. coli DNA ligase, exonucleases Ⅰ and Ⅲ. Briefly, S1 can digest both DNA templates, while the cleavage ability of DSN will be resistant by the short stem of SS-DNA(short-stem DNA). Exonuclease Ⅰ and Ⅲ can degrade these two nicked DNA templates, which are inhibited due to the ligation of E. coli DNA ligase. With this novel strategy, a set of logic gates is successfully constructed at the molecular level,including “YES”, “PASS 0”, “OR”, “INHIBIT”, which take the advantages of no label, easy operation, fast speed, high efficiency and low cost. Furthermore, S1 nuclease, as the biomarker of numerous carcinogens,is selectively detected in the range of 0.05–50 U/m L with the detection limit of 0.005 U/m L(1×10^(−6)U)based on this platform.

A dumbbell model with five parameters describing nuclear fusion or fission

We propose a five-parameter dumbbell model to describe the fusion and fission processes of massive nuclei, where the collective variables are： distance ρ between center-of-mass of two fusing nuclei, neck parameter ν, asymmetry D, two deformation variables β1 and β2. The present model has macroscopic qualitative expression of polarization and nuclear collision of head to head, sphere to sphere, waist to waist and so on. The conception of ＂projectile eating target＂ based on open mouth and swallow is proposed to describe nuclear fusion process, and then our understanding of the probability of fusion and quasi-fission is in agreement with some previous work. The calculated fission barriers of a lot of compound nuclei are compared with the experimental data.

Multiple bilateral and symmetric C1-2 ganglioneuromas: A case report

BACKGROUND Ganglioneuromas are rare tumors of the sympathetic nervous system that originate from neural crest sympathogonia.Since the cervical spine has rarely been reported as a site for ganglioneuroma,we present a case report on this uncommon manifestation.CASE SUMMARY A 34-year-old male presented with a 4-month history of progressive paralysis of both upper limbs along with an unsteady gait.The touch sensitivity of both hands was reduced,and there was conspicuously high muscle tonus in his upper and lower limbs,along with hyperactive physiological reflection and deep reflexes.Magnetic resonance imaging showed several nodules around the C2-7 intervertebral foramena,among which the masses lying between C1 and C2 were obviously bilaterally compressing the spinal cord.Successful posterior decompression was performed without fixation and the tumors in the upper cervical spine were removed intact,with rapid relief of symptoms.The pathological diagnosis was ganglioneuroma.CONCLUSION Multiple and bilateral ganglioneuroams are a rare occurrence in the cervical spine.In this case report,timely resection of the neoplasms around C1 and C2 resulted in spinal cord decompression,with rapid relief of symptoms and a good prognosis.Including the current case,we are aware of only seven such cases in the literature,of which four arose from Japan,one from China,and one from Sp-ain.We suppose that ethnicity and geographic associations with this rare disease presentation may be an aspect for future consideration and investigation.

Predicting 2D silicon allotropes on SnS2

A first principles study on the stability and structural and electronic properties of two-dimensional silicon allotropes on a semiconducfing layered metal-chalcogenide compound, namely SnS2, is performed. The interactions between the two- dimensional silicon layer, commonly known as silicene, and the layered SnS2 template are investigated by analyzing different configurations of silicene. The calculated thermodynamic phase diagram suggests that the most stable configuration of silicene on SnS2 belongs to a family of structures with Si atoms placed on three different planes; so-called dumbbell silicene. This particular dumbbell silicene structure preserves its atomic configuration on SnS2 even at a temperature of 500 K or as a ＂flake＂ layer （i.e., a silicene cluster terminated by H atoms）, thanks to the weak interactions between the silicene and the SnS2 layers. Remarkably, an electric field can be used to tune the band gap of the silicene layer on SnS2, eventually changing its electronic behavior from semiconducting to （semi）metallic. The stability of silicene on SnS2 is very promising for the integration of silicene onto semiconducting or insulating substrates. The tunable electronic behavior of the silicene/SnS2 van der Walls heterostructure is very important not only for its use in future nanoelectronic devices, but also as a successful approach to engineering the bang-gap of layered SnS2 paving the way for the use of this layered compound in energy harvesting applications.

A Constitutive Model Describing Molecular Configuration Evolution and Transient Rheological Behavior of Entangled Polymer Solutions

Entanglement network is an important structural feature in concentrated polymer solutions and polymer melts,which has a great influe nee on the transie nt rheological behavior and molecular con figurati on evolution.However,the existi ng constitutive models have limitations in describi ng the influe nee of dyn amic entan glement behavior on molecular chain motion,resulti ng in inaccurate descriptions of the transient rheological behavior.Thus,a molecular con figuration evoluti on model for polymer solutions considering the dyn amic entanglement effect is proposed by introducing an intermolecular force that changes with the orientation of the molecular chain in this work.The intermolecular force is introduced by consider!ng the friction coefficient as anisotropic,and the orientation effect is considered by introducing an excluded volume depende nt an isotropic diffusi on.The proposed model can better describe the stress relaxation,stress growth,and dielectric an isotropy of polymer soluti ons compared with the an isotropy FENE model and FENE model.In addition,the in fluence of different model parameters on the transient and steady shear response of polymer soluti on is investigated,and the results show that the in fluence of volume loss on the fricti on anisotropy factor k0 in creases as the solution concen tration in creases.

Convergence of a Stochastic Method for the Modeling of Polymeric Fluids

We present a convergence analysis of a stochastic method for numerical modeling of complex fluids using Brownian configuration fields (BCF) for shear flows. The analysis takes into account the special structure of the stochastic partial differential equations for shear flows. We establish the optimal rate of convergence. We also analyze the nature of the error by providing its leading order asymptotics.