Prognostic factors and clinical features of rhino-orbitalmucormycosis cases:an update for patient and visual survivals

AIM:To determine the frequency of patients’vision survival and prognostic factors and evaluate clinical features in rhino-orbital mucormycosis.METHODS:Forty-three eyes of 43 patients followed up with orbital mucormycosis infections were included in the study.Demographic characteristics of the patients,symptoms at admission,ophthalmologic and non-ophthalmologic examination findings,clinical findings during follow-up,medical and surgical procedures,and complications were recorded.Patient survival was determined by assessing the incidence of mortality,and vision survival was defined as achieving a final visual acuity of at least light perception.RESULTS:Twenty-seven(62.8%)patients were male,and 16(37.2%)were female.When the underlying disease status of the patients was examined,it was observed that all patients had an underlying disease and diabetes constituted the majority(65.2%).Periorbital swelling(69.8%)and ophthalmoplegia(53.5%)were the most common symptoms and findings at the admission of patients with mucormycosis infection.The disease resulted in death in 22(51.2%)patients.The presence of fever and shorter duration of antifungal therapy were associated with lower patient survival.Exenteration surgery was not found to be associated with the survival of the patients.Frozen eye,loss of pupillary light reflex,and development of central retinal artery occlusion were associated with lower vision survival.CONCLUSION:This study presents one of the most extensive patient series in the literature on rhino-orbital mucormycosis.Knowing the patients’symptoms at the time of admission and the clinical findings during the infection process will increase awareness about the disease.

d-d Orbital coupling induced by crystal-phase engineering assists acetonitrile electroreduction to ethylamine

The d-d orbital coupling induced by crystal-phase engineering can effectively adjust the electronic structure of electrocatalysts,thus showing significant catalytic performance,while it has been rarely explored in electrochemical acetonitrile reduction reaction(ARR)to date.Herein,we successfully realize the structural transformation of Pd Cu metallic aerogels(MAs)from face-centered cubic(FCC)to body-centered cubic(BCC)through annealing treatment.Specifically,the BCC Pd Cu MAs exhibit excellent ARR performance with high ethylamine selectivity of 90.91%,Faradaic efficiency of 88.60%,yield rate of 316.0 mmol h^(-1)g^(-1)_(Pd+Cu)and long-term stability for consecutive electrolysis within 20 h at-0.55 V vs.reversible hydrogen electrode,outperforming than those of FCC Pd Cu MAs.Under the membrane electrode assembly system,BCC Pd Cu MAs also demonstrate excellent ethylamine yield rate of 389.5 mmol h^(-1)g^(-1)_(Pd+Cu).Density functional theory calculation reveals that the d-d orbital coupling in BCC Pd Cu MAs results in an evident correlation effect for the interaction of Pd and Cu sites,which boosts up the Cu sites electronic activities to enhance ARR performance.Our work opens a new route to develop efficient ARR electrocatalysts from the perspective of crystalline structure transformation.

Generation of orbital angular momentum hologram using a modified U-net

Orbital angular momentum(OAM)holography has become a promising technique in information encryption,data storage and opto-electronic computing,owing to the infinite topological charge of one single OAM mode and the orthogonality of different OAM modes.In this paper,we propose a novel OAM hologram generation method based on a densely connected U-net(DCU),where the densely connected convolution blocks(DCB)replace the convolution blocks of the U-net.Importantly,the reconstruction process of the OAM hologram is integrated into DCU as its output layer,so as to eliminate the requirement to prepare training data for the OAM hologram,which is required by conventional neural networks through an iterative algorithm.The experimental and simulation results show that the OAM hologram can rapidly be generated with the well-trained DCU,and the reconstructed image's quality from the generated OAM hologram is significantly improved in comparison with those from the Gerchberg-Saxton generation method,the Gerchberg-Saxton based generation method and the U-net method.In addition,a 10-bit OAM multiplexing hologram scheme is numerically demonstrated to have a high capacity with OAM hologram.

Bessel–Gaussian beam-based orbital angular momentum holography

Orbital angular momentum(OAM), as a new degree of freedom, has recently been applied in holography technology.Due to the infinite helical mode index of OAM mode, a large number of holographic images can be reconstructed from an OAM-multiplexing hologram. However, the traditional design of an OAM hologram is constrained by the helical mode index of the selected OAM mode, for a larger helical mode index OAM mode has a bigger sampling distance, and the crosstalk is produced for different sampling distances for different OAM modes. In this paper, we present the design of the OAM hologram based on a Bessel–Gaussian beam, which is non-diffractive and has a self-healing property during its propagation. The Fourier transform of the Bessel–Gaussian beam is the perfect vortex mode that has the fixed ring radius for different OAM modes. The results of simulation and experiment have demonstrated the feasibility of the generation of the OAM hologram with the Bessel–Gaussian beam. The quality of the reconstructed holographic image is increased, and the security is enhanced. Additionally, the anti-interference property is improved owing to its self-healing property of the Bessel-OAM holography.

Manipulating d-d orbital hybridization induced by Mo-doped Co_(9)S_(8) nanorod arrays for high-efficiency water electrolysis

Precisely refining the electronic structure of electrocatalysts represents a powerful approach to further optimize the electrocatalytic performance.Herein,we demonstrate an ingenious d-d orbital hybridization concept to construct Mo-doped Co_(9)S_(8) nanorod arrays aligned on carbon cloth(CC)substrate(abbreviated as Mo-Co_(9)S_(8)@CC hereafter)as a high-efficiency bifunctional electrocatalyst toward water electrolysis.It has experimentally and theoretically validated that the 4d-3d orbital coupling between Mo dopant and Co site can effectively optimize the H_(2)O activation energy and lower H^(*)adsorption energy barrier,thereby leading to enhanced hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)activities.Thanks to the unique electronic and geometrical advantages,the optimized Mo-Co_(9)S_(8)@CC with appropriate Mo content exhibits outstanding bifunctional performance in alkaline solution,with the overpotentials of 75 and 234 mV for the delivery of a current density of 10 mA cm^(-2),small Tafel slopes of 53.8 and 39.9 mV dec~(-1)and long-term stabilities for at least 32 and 30 h for HER and OER,respectively.More impressively,a water splitting electrolylzer assembled by the self-supported Mo-Co_(9)S_(8)@CC electrode requires a low cell voltage of 1.53 V at 10 mA cm^(-2)and shows excellent stability and splendid reversibility,demonstrating a huge potential for affordable and scalable electrochemical H_(2) production.The innovational orbital hybridization strategy for electronic regulation herein provides an inspirable avenue for developing progressive electrocatalysts toward new energy systems.

High-Resolution Recognition of Orbital Angular Momentum Modes in Asymmetric Bessel Beams Assisted by Deep Learning

Fractional orbital angular momentum(OAM) vortex beams present a promising way to increase the data throughput in optical communication systems. Nevertheless, high-precision recognition of fractional OAM with different propagation distances remains a significant challenge. We develop a convolutional neural network(CNN)method to realize high-resolution recognition of OAM modalities, leveraging asymmetric Bessel beams imbued with fractional OAM. Experimental results prove that our method achieves a recognition accuracy exceeding 94.3% for OAM modes, with an interval of 0.05, and maintains a high recognition accuracy above 92% across varying propagation distances. The findings of our research will be poised to significantly contribute to the deployment of fractional OAM beams within the domain of optical communications.

Orbital-Ordering Driven Simultaneous Tunability of Magnetism and Electric Polarization in Strained Monolayer VCl_(3)

Two-dimensional(2D)van der Waals magnetic materials have promising and versatile electronic and magnetic properties in the 2D limit,indicating a considerable potential to advance spintronic applications.Theoretical predictions thus far have not ascertained whether monolayer VCl_(3) is a ferromagnetic(FM)or anti-FM monolayer;this also remains to be experimentally verified.We theoretically investigate the influence of potential factors,including C_(3) symmetry breaking,orbital ordering,epitaxial strain,and charge doping,on the magnetic ground state.Utilizing first-principles calculations,we predict a collinear type-Ⅲ FM ground state in monolayer VCl_(3) with a broken C_(3) symmetry,wherein only the former two of three t_(2g)orbitals(a_(1g),e_(g2)^(π)and e_(g1)^(π))are occupied.The atomic layer thickness and bond angles of monolayer VCl_(3) undergo abrupt changes driven by an orbital ordering switch,resulting in concomitant structural and magnetic phase transitions.Introducing doping to the underlying Cl atoms of monolayer VCl_(3) without C_(3) symmetry simultaneously induces in-and out-of-plane polarizations.This can achieve a multiferroic phase transition if combined with the discovered adjustments of magnetic ground state and polarization magnitude under strain.The establishment of an orbital-ordering driven regulatory mechanism can facilitate deeper exploration and comprehension of magnetic properties of strongly correlated systems in monolayer VCl_(3).

Theory for Charge Density Wave and Orbital-Flux State in Antiferromagnetic Kagome Metal FeGe

We theoretically study the charge order and orbital magnetic properties of a new type of antiferromagnetic kagome metal FeGe.Based on first-principles density functional theory calculations,we study the electronic structures,Fermi-surface quantum fluctuations,as well as phonon properties of the antiferromagnetic kagome metal FeGe.It is found that charge density wave emerges in such a system due to a subtle cooperation between electron-electron interactions and electron–phonon couplings,which gives rise to an unusual scenario of interaction-triggered phonon instabilities,and eventually yields a charge density wave(CDW)state.We further show that,in the CDW phase,the ground-state current density distribution exhibits an intriguing star-of-David pattern,leading to flux density modulation.The orbital fluxes(or current loops)in this system emerge as a result of the subtle interplay between magnetism,lattice geometries,charge order,and spin-orbit coupling(SOC),which can be described by a simple,yet universal,tight-binding theory including a Kane-Mele-type SOC term and a magnetic exchange interaction.We further study the origin of the peculiar step-edge states in FeGe,which sheds light on the topological properties and correlation effects in this new type of kagome antiferromagnetic material.

Asymmetric orbital hybridization in Zn-doped antiperovskite Cu_(1-x)Zn_(x)NMn_(3)enables highly efficient electrocatalytic hydrogen production

Rational design of efficient and robust earth-abundant alkaline hydrogen evolution reaction(HER)catalysts is a key factor for developing energy conversion technologies.Currently,antiperovskite nitride CuNMn_(3)has garnered significant interest due to its remarkable properties such as negative/zero thermal expansion and magnetocaloric effects.However,when utilized as hydrogen evolution catalysts,it encounters large challenge resulting from excessively strong/weak interactions with adsorbed H on Mn/Cu active sites,which leads to low HER activity.In this study,we introduce an asymmetric orbital hybridization strategy in Zn-doped Cu_(1-x)Zn_(x)NMn_(3)by leveraging the localization of Zn electronic states to reconfigure the electronic structures of Cu and Mn,thereby reducing the energy barrier for water dissociation and optimizing Cu and Mn active sites for hydrogen adsorption and H_(2)production.Electrochemical evaluations reveal that Cu_(0.85)Zn_(0.15)NMn_(3)with x=0.15 demonstrates exceptional electrocatalytic activity in alkaline electrolytes.A low overpotential of 52 mV at 10 mA cm^(-2)and outstanding stability over a 150-h test period are achieved,surpassing commercial Pt/C.This research offers a novel strategy for enhancing HER performance by modulating asymmetric hybridization of electron orbitals between multiple metal atoms within a material structure.

Effect of navigation endoscopy combined with threedimensional printing technology in the treatment of orbital blowout fractures

●AIM:To explore the combined application of surgical navigation nasal endoscopy(NNE)and three-dimensional printing technology(3DPT)for the adjunctive treatment of orbital blowout fractures(OBF).●METHODS:Retrospective analysis was conducted on the data of patients with OBF who underwent surgical treatment at the Affiliated Eye Hospital of Nanchang University between July 2012 and November 2022.The control group consisted of patients who received traditional surgical treatment(n=43),while the new surgical group(n=52)consisted of patients who received NNE with 3DPT.The difference in therapeutic effects between the two groups was evaluated by comparing the duration of the operation,best corrected visual acuity(BCVA),enophthalmos difference,recovery rate of eye movement disorder,recovery rate of diplopia,and incidence of postoperative complications.●RESULTS:The study included 95 cases(95 eyes),with 63 men and 32 women.The patients’age ranged from 5 to 67y(35.21±15.75y).The new surgical group and the control group exhibited no statistically significant differences in the duration of the operation,BCVA and enophthalmos difference.The recovery rates of diplopia in the new surgical group were significantly higher than those in the control group at 1mo[OR=0.03,95%CI(0.01–0.15),P<0.0000]and 3mo[OR=0.11,95%CI(0.03–0.36),P<0.0000]postoperation.Additionally,the recovery rates of eye movement disorders at 1 and 3mo after surgery were OR=0.08,95%CI(0.03–0.24),P<0.0000;and OR=0.01,95%CI(0.00–0.18),P<0.0000.The incidence of postoperative complications was lower in the new surgical group compared to the control group[OR=4.86,95%CI(0.95–24.78),P<0.05].●CONCLUSION:The combination of NNE and 3DPT can shorten the recovery time of diplopia and eye movement disorder in patients with OBF.

Exploring the role of iron in Fe_(5)Ni_(4)S_(8)toward oxygen evolution through modulation of electronic orbital occupancy

Ni-Fe-based catalysts are considered to be among the most active catalysts for the oxygen evolution reaction(OER)under alkaline conditions,with Fe playing a crucial role.However,Fe leaching occurs during the reaction due to thermodynamic instability,which has resulted in conflicting reports within the literature regarding its role.To clarify this point,we propose a strategy consisting of modulating the electronic orbital occupancy to suppress the extensive loss of Fe atoms during the OER process.Theoretical calculations,in-situ X-ray photoelectron spectroscopy,molecular dynamics simulations,and a series of characterization showed that the stable presence of Fe not only accelerates the electron transfer process but also optimizes the reaction barriers of the oxygen evolution intermediates,promoting the phase transition of Fe_(5)Ni_(4)S_(8)to highly active catalytic species.The modulated Fe_(5)Ni_(4)S_(8)-based pre-catalysts exhibit improved OER activity and long-term durability.This study provides a novel perspective for understanding the role of Fe in the OER process.

Late infection after peri-orbital autologous micro-fat graft:a case presentation and literature review

Citation:Pakdel F,Asadigandomani H,Arab Bafrani M,Nozarian Z,Abedinifar Z,Pirmarzdashti N,Jafari B,Siami Z.Late infection after peri-orbital autologous micro-fat graft:a case presentation and literature review.Int J Ophthalmol 2024;17(3):603-606.

Robust measurement of orbital angular momentum of a partially coherent vortex beam under amplitude and phase perturbations

The ability to overcome the negative effects,induced by obstacles and turbulent atmosphere,is a core challenge of long-distance information transmission,and it is of great significance in free-space optical communication.The spatial-coherence structure,that characterizes partially coherent fields,provides a new degree of freedom for carrying information.However,due to the influence of the complex transmission environment,the spatial-coherence structure is severely damaged during the propagation path,which undoubtedly limits its ability to transmit information.Here,we realize the robust far-field orbital angular momentum(OAM)transmission and detection by modulating the spatial-coherence structure of a partially coherent vortex beam with the help of the cross-phase.The cross-phase enables the OAM information,quantified by the topological charge,hidden in the spatial-coherence structure can be stably transmitted to the far field and can resist the influence of obstructions and turbulence within the communication link.This is due to the self-reconstruction property of the spatial-coherence structure embedded with the cross-phase.We demonstrate experimentally that the topological charge information can be recognized well by measuring the spatial-coherence structure in the far field,exhibiting a set of distinct and separated dark rings even under amplitude and phase perturbations.Our findings open a door for robust optical signal transmission through the complex environment and may find application in optical communication through a turbulent atmosphere.

Orbital liposarcoma: a retrospective, single-center study of thirteen patients

AIM:To explore the clinical and pathological characteristics of thirteen patients with orbital liposarcoma.METHODS:The clinical history data of thirteen patients diagnosed as orbital liposarcoma at Beijing Tongren Hospital,from 2006 to 2021 were collected and analyzed.The data includes age,gender,affected orbital side,course of disease,status of disease(primary or recurrent),clinical manifestations,preoperative visual acuity,operative treatment,the relations between liposarcoma and surrounding tissue,longest diameter of liposarcoma,histological subtype,immunohistochemical indicators,follow-up treatment and prognosis.RESULTS:The initial symptoms are diverse.Proptosis is the most frequent chief complaint and the others included vision loss,epiphora,diplopia,and eyelid palpable mass.Results of imaging examination[computed tomography(CT)or magnetic resonance imaging(MRI)]showed orbital mass.In terms of treatment,10 patients received tumor resection,and the mean longest diameter of the tumor was 3.39±1.36 cm.The other 3 patients had optic nerve invaded,so they received orbital exenteration.Pathological examination results confirmed the diagnose of liposarcoma for 13 patients.Six patients displayed as myxoid type,and three patients in each type of dedifferentiated and welldifferentiated type.One patient was verified as pleomorphic,which was a rare type of liposarcoma.All of the patients showed Vimentin positive,and most showed CD34 and S-100 positive.Besides,four patients showed smooth muscle actin positive.All thirteen patients were alive.CONCLUSION:Orbital liposarcoma is a rare disease and it has no specific clinical manifestation.The diagnosis of liposarcoma should be considered when proptosis and orbital mass occurred in orbit.It is recommended to perform pathological examination to achieve early detection and early treatment.

Accuracy between clinical and radiological diagnoses compared to surgical orbital biopsies

AIM:To assess the concordance between diagnosing orbital lesions by clinical examination,orbital imaging,and histological evaluation,in order to help guide future research and clinical practice.METHODS:A retrospective analysis was undertaken at a large regional tertiary referral centre of all surgical orbital biopsies performed over a 5-year period,from 1st January 2015 until 31st December 2019.Accuracy and concordance between clinical,radiological and histological diagnoses are reported as percentage sensitivity and positive predictive value.RESULTS:A total of 128 operations involving 111 patients were identified.Overall,sensitivities of 47.7%for clinical and 37.3%for radiological diagnoses were found when compared to the histological gold standard.Vascular lesions that have characteristic clinical and radiological features had the highest sensitivity at 71.4%and 57.1%,respectively.Inflammatory conditions showed the lowest sensitivity in both clinical(30.3%)and radiological(18.2%)diagnoses.The PPV for inflammatory conditions were 47.6%for clinical and 30.0%for radiological diagnoses.CONCLUSION:Accurate diagnoses are difficult to reach by relying on clinical examination and imaging alone.Surgical orbital biopsy with histological diagnosis should remain the gold standard approach for definitively identifying orbital lesions.Although larger scale prospective studies would help further refine concordance and guide future research avenues.

Clinical features,radiological imaging,and treatment strategies of nonmetallic intraorbital foreign bodies:a retrospective analysis

AIM:To provide comprehensive data on nonmetallic intraorbital foreign bodies(IOFBs)by summarizing and analyzing material types,clinical manifestations,imaging features,and treatment strategies.METHODS:Totally 28 nonmetallic IOFB cases treated at Shengjing Hospital of China Medical University from 2012 to 2020 were retrospectively reviewed.The types of foreign bodies,clinical features,imaging manifestations,and treatment outcomes were analyzed.RESULTS:Among all cases,67.8%(19/28)of the foreign bodies were organic.The top three entrances were the upper eyelid skin(7/28),lower fornix conjunctiva(6/28),and lower eyelid skin(4/28).In most cases(11/28,39.3%),foreign bodies remained in the medial orbits.The major clinical manifestations included eyelid redness and swelling(20/28,71.4%),conjunctival congestion and edema(17/28,60.7%),and ophthalmoptosis(15/28,53.6%).Infection was the main complication,which occurred in 57.1%(16/28)of all cases.Computerized tomography(CT)values differed for different foreign bodies and varied in the different periods after injury.The plant-and grease-derived foreign bodies and the surrounding pus cysts showed different signals on magnetic resonance imaging(MRI).The prognosis varied with different foreign body types,surgery timing,and intraoperative management.CONCLUSION:The majority of nonmetallic IOFBs are organic and often remain in the superior,medial,and inferior areas of the orbit.Clinical manifestations vary owing to their different textures.CT and MRI facilitate the identification of foreign body materials.Plant-derived foreign bodies should be completely removed,and surgical treatment is a complicated process.

Asymmetrical spiral spectra and orbital angular momentum density of non-uniformly polarized vortex beams in uniaxial crystals

To explore the effect of non-uniform polarization on orbital angular momentum(OAM) in anisotropic medium, in this work investigated are the evolution of the spiral spectra and OAM densities of non-uniformly polarized vortex(NUPV)beams in uniaxial crystals propagating orthogonal to the optical axis, and also the case of uniformly polarized vortex(UPV)beams with left-handed elliptical polarization. In the input plane, the NUPV beams present their spiral spectra of m-mode concentrated at m = l ± 1 modes rather than m = l mode, and reveal the relation among topological charge l, mode of spiral spectra m and the power weight value Rmexpressed by l=∑^(∞)_(m)=-∞Rm. is still satisfied for UPV beams in uniaxially anisotropic crystals, whereas for NUPV beams their relations are no longer valid owing to non-uniform polarization. Furthermore, the analysis indicates that the asymmetrical distribution of power weight of spiral spectra and the non-zero value in the sum of longitudinal OAM densities originate from the initial non-uniform polarization and anisotropy in uniaxial crystals rather than topological charges. In addition, the relation between spiral spectrum and longitudinal OAM density is numerically discussed. This work may provide an avenue for OAM-based communications,optical metrology, and imaging by varying the initial non-uniform polarization.

Difference of anterior and posterior orbital development in patients with congenital microphthalmia:a retrospective cohort study from China

AIM:To evaluate volume differences between anterior and posterior orbit and demographic characteristics of Chinese patients with congenital microphthalmia.METHODS:A retrospective cohort study,involving 169 unilateral congenital microphthalmia patients aged between 1 and 57 years old was conducted.Three-dimensional images of the orbit were generated from past CT scans,and digital orbital volume comprehensive measurement was done.The measured data included orbital volume(OBV),posterior orbital volume(POV),orbital width(OBW),orbital height(OBH),orbital depth(OBD),and posterior orbital area ratio.RESULTS:Significant differences were observed among OBV,POV,OBW,OBH,and OBD of the affected and unaffected eyes in different age-based groups(all P<0.001).Among them,OBH had the greatest different.The mean microphthalmic to contralateral ratio(MCR) of OBV,POV,OBW,and OBH continuously increased from 1 to 3 years old,whereas the MCR of POV decreased from 3 to 17 years old.The MCR of OBD was not found to be correlated to age.There was no significant difference between OBV,POV,OBW,and OBH in ages from 13 years old to adulthood(all P>0.05).The difference in posterior orbital area ratio between the affected and unaffected groups was not statistically significant(P>0.05).CONCLUSION:OBH is maximally affected,whereas OBD is minimally affected by microphthalmia.Posterior orbital retardation began 2y prior to orbital retardation and occurred at 3 years old in the affected eye,suggesting that intervention therapy should be done before the age of 4.

Modulating Pd e_(g) orbital occupancy in Pd-Au metallic aerogels for efficient carbon dioxide reduction

The electronic structure of electrocatalysts plays a critical role in energy conversion,whereas for an efficient catalyst,it is challenging to modulate the orbitals.Herein,we present a new strategy to modulate the e_(g) orbital occupancy of Pd by constructing composition-controllable Pd-Au metallic aerogels(MAs),optimizing the d-band center of Pd to achieve excellent performance for electrochemical carbon dioxide reduction reaction(CO_(2)RR).Specifically,Pd_(1)Au_(2) MAs achieve almost 100% Faraday efficiency(FE) of CO in the range of-0.40 to-0.80 V vs.reversible hydrogen electrode(RHE),as well as the long-term stability,being one of the best Pd-based materials for CO_(2)RR.The X-ray photoelectron spectroscopy(XPS) results and density functional theory(DFT) calculations demonstrate that the introduction of Au modulates the Pd e_(g) orbital occupancy,which significantly weakens *CO adsorption on Pd,reduces the CO_(2)RR energy barrier and consequently improves the electrocatalytic activity and stability for long-term applications.Our work highlights a new strategy for designing efficient electrocatalysts for CO_(2)RR and beyond.

A two-step method to detect broadcast ephemeris unavailable periods caused by BeiDou satellite orbital maneuvers

The space constellation of the BeiDou navigation satellite system(BDS) is a hybrid constellation containing medium earth orbit(MEO) satellites, geostationary earth orbit(GEO) satellites, and inclined geosynchronous orbit(IGSO) satellites. Due to the geosynchronous characteristics of GEO and IGSO, GEO satellites and IGSO satellites often need to perform orbital maneuvers, which can affect the signal-inspace(SIS) availability performance of BeiDou satellites. A two-step detection method for BeiDou satellite orbital maneuvers has been proposed in this paper. The first step is to identify orbital maneuvers based on time series analysis of broadcast ephemeris, and the second step is to verify orbital maneuvers based on bidirectional orbit prediction. The two-step detection method was used to detect the orbital maneuvers of BeiDou satellites in 2019. Through the double guarantees of identification and verification,the detection accuracy of BeiDou satellite orbital maneuvers has been effectively improved. And the orbital maneuver detection results are continued to be used to assess the SIS availability of BeiDou satellites. The results show that the availability loss of GEO satellite orbital maneuvers is about 0.45%-1.07%, and the availability loss of IGSO satellite orbital maneuvers is about 0.12%-0.19%.