The Incidence and Risk Factors of Third- and Fourth-Degree Perineal Tears in Ministry of Health in Bahrain over 5 Years

Background: Perineal trauma and vaginal laceration are considered a common complication associated with vaginal delivery. Well established risk factors, recognized by the Royal College of Obstetricians and Gynecologists, are ethnicity, birth weight over 4 kg persistent occipital posterior position, null parity, induction of labor, shoulder dystocia, instrumental delivery. There are other risk factors that were suggested in the literature, but data are conflicting, such as prolonged second stage of labor, episiotomy and obesity. Objective: To evaluate third- and fourth-degree perineal rears rates and the impact of related risk factors on perineal tears in Ministry of health in Bahrain over 5 years (which includes Salmanyia Medical complex (SMC) and Jidhafs maternity hospital (JMH)). Methods: This retrospective descriptive cross-sectional study analyzed all vaginal deliveries from January 2015 to December 2019 in Obstetrics and Gynecology department in Salmanyia Medical Complex (the main hospital in Kingdom of Bahrain which received all kinds of cases including low and high risks) and Jidhafs Maternity Hospital (tertiary hospital which received only low risk cases), Kingdom of Bahrain. During the period of interest 33,694 records were identified. Data were extracted from observational recording from SMC and JMH labour registry books. Results: There was no statistically significant difference between groups according to age (p = 0.199). On the other hand, there was statistically significant higher cases of >40 weeks at gestational age, obesity > 35 kg/mr, vacuum delivery, pushing stage > 90 min, birth weight > 4 kg, head circumference > 34 cm, fetal length at birth > 50 cm, episiotomy and lower cases of nulliparity in study group compared to control group 16 (66.7%) vs. 13,805 (41.0%), 3 (12.5%) vs. 1448 (4.3%), 3 (12.5%) vs. 1414 (4.2%), 4 (16.7%) vs. 1751 (5.2%), 3 (12.5%) vs. 1751 (5.2%), 12 (50.0%) vs. 15,926 (47.3%), 15 (62.5%) vs. 20,135 (59.8%) and 17 (70.8%) vs. 29,024 (86.2%);(p = 0.027, 0.009, Conclusion: Gestational age > 40 weeks, obesity > 35 kg/mr, pushing stage > 90 min, birth weight > 4 kg, head circumference > 34 cm, fetal length at birth > 50 cm and using of vacuum increase incidence of 3rd and 4th degree perineal tears with vaginal delivery however maternal age and nulliparity have no significant role. Finally, episiotomy did not represent as protective factor for perineal damage. .

Preliminary proteomic analysis of human tears in lacrimal adenoid cystic carcinoma and pleomorphic adenoma

·AIM: To detect proteomic differences in tears between adenoid cystic carcinoma(ACC) and pleomorphic adenoma(PA).·METHODS: Tear samples were collected from 4 patients with ACC, 5 with PA, and 4 control cases. Label-free analysis and parallel reaction monitoring(PRM) were used to screen and validate the tear proteome. Gene Ontology(GO) annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG) were conducted for bioinformatics analysis.·RESULTS: In total, 1059 proteins in tear samples were identified by label-free analysis. Between ACC and PA, 415 differentially expressed proteins were detected. Based on the GO annotation, enzyme regulator activity and serinetype endopeptidase inhibitor activity in the molecular function category, blood microparticle and extracellular matrix in the cellular component category, and response to nutrient levels in the biological process category were most predominant. By KEGG pathway annotation, the different proteins between ACC and PA mainly par ticipated in complement and coagulation cascades, amoebiasis, African trypanosomiasis and cholesterol metabolism. Eight proteins with mostly significant differences were verified by PRM, and five proteins with more than 10-fold increases in ACC compared with PA, including integrin β, α-2-macroglobulin, epididymal secretory sperm binding protein Li 78p, RAB5C, and complement C5, were identified.·CONCLUSION: The combined tools of label-free analysis and PRM are very effective and efficient, especially for samples such as tears. Some proteomic dif ferences in tears between ACC and PA are identified and these protein candidates may be specific biomarkers for future exploration.

Long head of biceps tendon transposition for massive and irreparable rotator cuff tears:A systematic review and meta-analysis

BACKGROUND Superior capsular reconstruction(SCR)with long head of biceps tendon(LHBT)transposition was developed to massive and irreparable rotator cuff tears(MIRCTs);however,the outcomes of this technique remain unclear.AIM To perform a systematic review of biomechanical outcomes and a meta-analysis of clinical outcomes after LHBT transposition for MIRCTs.METHODS We performed a systematic electronic database search on PubMed,EMBASE,and Cochrane Library.Studies of SCR with LHBT transposition were included according to the inclusion and exclusion criteria.Biomechanical studies were assessed for main results and conclusions.Included clinical studies were evaluated for quality of methodology.Data including study characteristics,cohort demographics,and outcomes were extracted.A meta-analysis was conducted of the clinical outcomes.RESULTS According to our inclusion and exclusion criteria,a total of six biomechanical studies were identified and reported an overall improvement in subacromial contact pressures and prevention of superior humeral migration without limiting range of motion(ROM)after LHBT transposition for MIRCTs.A total of five clinical studies were included in the meta-analysis of LHBT transposition outcomes,consisting of 253 patients.The results indicated that compared to other surgical methods for MIRCTs,LHBT transposition had advantages of more significant improvement in ROM(forward flexion mean difference[MD]=6.54,95%confidence interval[CI]:3.07-10.01;external rotation[MD=5.15,95%CI:1.59-8.17];the acromiohumeral distance[AHD][MD=0.90,95%CI:0.21-1.59])and reducing retear rate(odds ratio=0.27,95%CI:0.15-0.48).No significant difference in American Shoulder and Elbow Surgeons score,visual analogue scale score,and University of California at Los Angles score was demonstrated between these two groups for MIRCTs.CONCLUSION In general,SCR with LHBT transposition was a reliable and economical technique for treating MIRCTs,both in terms of biomechanical and clinical outcomes,with comparable clinical outcomes,improved ROM,AHD,and reduced the retear rates compared to conventional SCR and other established techniques.More high-quality randomized controlled studies on the long-term outcomes of SCR with LHBT transposition are required to further assess.

Multi-dimensional multiplexing optical secret sharing framework with cascaded liquid crystal holograms

Secret sharing is a promising technology for information encryption by splitting the secret information into different shares.However,the traditional scheme suffers from information leakage in decryption process since the amount of available information channels is limited.Herein,we propose and demonstrate an optical secret sharing framework based on the multi-dimensional multiplexing liquid crystal(LC)holograms.The LC holograms are used as spatially separated shares to carry secret images.The polarization of the incident light and the distance between different shares are served as secret keys,which can significantly improve the information security and capacity.Besides,the decryption condition is also restricted by the applied external voltage due to the variant diffraction efficiency,which further increases the information security.In implementation,an artificial neural network(ANN)model is developed to carefully design the phase distribution of each LC hologram.With the advantage of high security,high capacity and simple configuration,our optical secret sharing framework has great potentials in optical encryption and dynamic holographic display.

Meniscus tears treatment:The good,the bad and the ugly-patterns classification and practical guide

Over the years,several studies demonstrated the crucial role of knee menisci in joint biomechanics.As a result,save the meniscus has become the new imperative nowadays,and more and more studies addressed this topic.The huge amount of data on this topic may create confusion in those who want to approach this surgery.The aim of this review is to provide a practical guide for treatment of meniscus tears,including an overview of technical aspects,outcomes in the literature and personal tips.Taking inspiration from a famous movie directed by Sergio Leone in 1966,the authors classified meniscus tears in three categories:The good,the bad and the ugly lesions.The inclusion in each group was determined by the lesion pattern,its biomechanical effects on knee joint,the technical challenge,and prognosis.This classification is not intended to substitute the currently proposed classifications on meniscus tears but aims at offering a readerfriendly narrative review of an otherwise difficult topic.Furthermore,the authors provide a concise premise to deal with some aspects of menisci phylogeny,anatomy and biomechanics.

Late presentation of dural tears:Two case reports and review of literature

BACKGROUND The late presentation of dural tears(LPDT)has a low incidence rate and hidden symptoms and is easily ignored in clinical practice.If the disease is not treated in time,a series of complications may occur,including low intracranial pressure headache,infection,pseudodural cyst formation,and sinus formation.Here,we describe two cases of LPDT.CASE SUMMARY Two patients had sudden fever 1 wk after lumbar surgery.Physical examination showed obvious tenderness in the operation area.The patients were confirmed as having LPDT by lumbar magnetic resonance imaging and surgical exploration.One case was caused by continuous negative pressure suction and malnutrition,and the other was caused by decreased dural ductility and low postoperative nutritional status.The first symptom of both patients was fever,with occasional headache.Both patients underwent secondary surgery to treat the LPDT.Dural defects were observed and dural sealants were used to seal the dural defects,then drainage tubes were retained for drainage.After the operation,the patients were treated with antibiotics and the patients’surgical incisions healed well,without fever or incision tenderness.Both recovered and were discharged 1 wk after the operation.CONCLUSION LPDT is a rare complication of spinal surgery or neurosurgery that has hidden symptoms and can easily be overlooked.Since it may cause a series of complic-ations,LPDT needs to be actively addressed in clinical practice.

The Effect of Umami Stimulation on Salivary Secretion Rate and Duration

Purpose: Umami reportedly promotes salivation. We aimed to investigate the effects of taste stimuli on slow and fast salivary secretion in humans using umami, sweet, and sour stimuli. Methods: Eight healthy women participated between 14:00 and 15:00, taking the circadian rhythm of salivary secretion into account. The types and concentrations of the taste solutions were glutamic acid (1.7 × 10−3 M), inosinic acid (9.8 × 10−3 M), and guanylic acid (9.8 × 10−3 M) for umami stimulation, citric acid (6.5 × 10−3 M) for acidity stimulation, and sucrose (1.6 × 10−2 M) for sweetness stimulation. First, the unstimulated salivary flow rate was measured. Then, 3 ml of a flavor solution was dropped under the tongue using a syringe. The saliva was expelled into an aluminum cup every minute and weighed. The first minute’s value minus 3 ml flavor solution was the stimulated salivary secretion rate produced by each flavor. The time-to-return to the initial unstimulated salivary flow rate was the duration of the stimulated saliva secretion rate. Results: The mean unstimulated salivary flow rate across participants was 0.64 ± 0.25 ml/min (range: 0.23 - 1.03 ml/min). The highest amount of saliva was induced by citric acid. There were significant differences between citric acid and the other flavor solutions (p < 0.05 for glutamic acid, inosinic acid, and sucrose;p < 0.01 for guanylic acid). There were no significant differences in duration of salivation between the flavor solutions. When the participants were divided into slow (0.45 ± 0.16 ml/min) and fast groups (0.83 ± 0.15 ml/min) based on their median resting salivary secretion rate, there were no significant differences between the two groups in the amount of saliva secreted at 1 minute after stimulation and the duration of the salivary secretion rate. Conclusion: Umami stimulation was effective in slowing salivary secretion and sustaining salivary secretion after stimulation.

Assessment of tear film parameters post-treatment with commercial eyelid cleaning wipes:a pilot study

AIM:To investigate the short-term effects of commercially available eyelid-cleaning wipes on film parameters.METHODS:This study enrolled 48 healthy participants aged 20-35y(both males and females).Clinical assessment included the Ocular Surface Disease Index(OSDI)questionnaire,non-invasive tear break-up time(NITBUT),tear meniscus height(TMH),and lipid layer pattern(LLP).Based on these initial results,participants were categorized as either non-dry eye or dry eye.Participants in each group were randomly allocated to either Blephaclean■or Systane■treatments.Changes in NITBUT,TMH,and LLP levels before and after lid wipe treatment were assessed.RESULTS:The dry eye group exhibited significantly higher OSDI scores and lower NITBUT and TMH levels than in the non-dry eye group(P<0.001).Following the application of eyelid wipes(Systane■wipes),dry eye subjects experienced a significant improvement in NITBUT levels(P=0.0014)compared to the non-dry eye individuals.Although the remaining participants showed a marginal increase in TMH and NITBUT levels,these changes did not achieve statistical significance(P>0.05).Similarly,the LLP levels were significantly improved with Systane■(P<0.001)post-treatment compared to individuals in the non-dry eye group.However,the dry eye subjects showed higher posttreatment LLP levels than the untreated group(P<0.02).CONCLUSION:The short-term effects of Systane®eyelid wipes on tear film parameters suggest their effectiveness in dry eye disease.Nonetheless,further exploration of their long-term impact is essential to justify their cost effectiveness and efficacy in treating both aqueous deficiency and evaporative dryness.

Suppression of the m/n=2/1 tearing mode by electron cyclotron resonance heating on J-TEXT

Stabilization of tearing modes and neoclassical tearing modes is of great importance for tokamak operation.Electron cyclotron waves(ECWs)have been extensively used to stabilize the tearing modes with the virtue of highly localized power deposition.Complete suppression of the m/n=2/1 tearing mode(TM)by electron cyclotron resonance heating(ECRH)has been achieved successfully on the J-TEXT tokamak.The effects of ECW deposition location and power amplitude on the 2/1 TM suppression have been investigated.It is found that the suppression is more effective when the ECW power is deposited closer to the rational surface.As the ECW power increases to approximately 230 k W,the 2/1 TM can be completely suppressed.The island rotation frequency is increased when the island width is reduced.The experimental results show that the local heating inside the magnetic island and the resulting temperature perturbation increase at the O-point of the island play dominant roles in TM suppression.As the ECW power increases,the 2/1 island is suppressed to smaller island width,and the flow shear also plays a stabilizing effect on small magnetic islands.With the stabilizing contribution of heating and flow shear,the 2/1 TM can be completely suppressed.

Pro-inflammatory cytokines levels in tears and dry eye disease in Parkinson’s disease

Background:Neuroinflammation is an essential event in Parkinson’s disease(PD).Identifying affordable and less invasive biomarkers to make an early diagnosis and monitor therapeutic strategies should be a priority among researchers.The study’s objective was to measure tear levels of cytokines in subjects with PD and their association with motor features and the presence of dry eye symptoms.Methods:A total of 16 subjects with PD and 16 age-and sex-matched controls were included.Movement Disorders Society-Unified Parkinson’s Disease Rating Scale(MDS-UPDRS),Hoehn and Yahr(HY)stage scale,Montreal Cognitive Assessment(MoCA),tear break-up time(TBUT),blink rate(BR),Dry Eye Questionnaire 5(DEQ-5)were examined,and pro-inflammatory cytokines[interleukin(IL)-1β,IL-6,IL-8,IL-10,IL-12p70 and tumor necrosis factor-alpha(TNF-α)]were quantified in tears using the BD Cytometric Bead Array Human Inflammatory Cytokine Kit.Results:Higher tear TNF-αwere quantified in PD compared to controls(2.94±3.95 vs.0.33±0.49 pg/mL,P=0.008).According to DEQ-5,50.0%(n=8)of PD subjects and 12.5%(n=2)controls had dry eye disease(DED).No differences were found in cytokines concentrations between PD patients with DED compared to those without DED.IL-8 was associated with the HY stage,TBUT,DEQ-5,and a better MoCA score.A higher BR correlated moderately with a lower HY stage(r=−0.645,P=0.007),and DED patients have lower BR in PD(12.14±2.54 vs.9.0±2.06 blinks/minute,P=0.031).Conclusions:PD patients have higher levels of TNF-αin tears than age-and sex-matched HC.IL-8 in tears may be both involved in the severity of the disease and in the development of DED in PD.In addition,our findings suggest that as HY stage increases,indicating a more advanced stage,BR decreases,indicating greater motor impairment.Conversely,the presence of DED is associated with higher levels of bradykinesia in PD patients,suggesting a potential relationship between DED and motor impairment severity.

Effects of diamagnetic drift on nonlinear interaction between multi-helicity neoclassical tearing modes

A numerical study of the diamagnetic drift effect on the nonlinear interaction between multi-helicity neoclassical tearing modes(NTMs) is carried out using a set of four-field equations including two-fluid effects.The results show that,in contrast to the single-fluid case,5/3 NTM cannot be completely suppressed by 3/2 NTM with diamagnetic drift flow.Both modes exhibit oscillation and coexist in the saturated phase.To better understand the effect of the diamagnetic drift flow on multiple-helicity NTMs,the influence of typical relevant parameters is investigated.It is found that the average saturated magnetic island width increases with increasing bootstrap current fraction f_(b) but decreases with the ion skin depth δ.In addition,as the ratio of parallel to perpendicular transport coefficients χ_(‖)/χ_(⊥) increases,the average saturated magnetic island widths of the 3/2 and 5/3 NTMs increase.The underlying mechanisms behind these observations are discussed in detail.

Microstructure and Hot Tearing Sensitivity Simulation and Parameters Optimization for the Centrifugal Casting of Al-Cu Alloy

Four typical theories on the formation of thermal tears:strength,liquid film,intergranular bridging,and solidifica-tion shrinkage compensation theories.From these theories,a number of criteria have been derived for predicting the formation of thermal cracks,such as the stress-based Niyama,Clyne,and RDG(Rapaz-Dreiser-Grimaud)criteria.In this paper,a mathematical model of horizontal centrifugal casting was established,and numerical simulation analysis was conducted for the centrifugal casting process of cylindrical Al-Cu alloy castings to investigate the effect of the centrifugal casting process conditions on the microstructure and hot tearing sensitivity of alloy castings by using the modified RDG hot tearing criterion.Results show that increasing the centrifugal rotation and pouring speeds can refine the microstructure of the alloy but increasing the pouring and mold preheating temperatures can lead to an increase in grain size.The grain size gradually transitions from fine grain on the outer layer to coarse grain on the inner layer.Meanwhile,combined with the modified RDG hot tearing criterion,the overall distribution of the castings’hot tearing sensitivity was analyzed.The analysis results indicate that the porosity in the middle region of the casting was large,and hot tearing defects were prone to occur.The hot tearing tendency on the inner side of the casting was greater than that on the outer side.The effects of centrifugal rotation speed,pouring temperature,and preheating temperature on the thermal sensitivity of Al-Cu alloy castings are summarized in this paper.This study revealed that the tendency of alloy hot cracking decreases with the increase of the centrifugal speed,and the maximum porosity of castings decreases first and then increases with the pouring temperature.As the preheating temperature increases,the overall maximum porosity of castings shows a decreasing trend.

A verifiable essential secret image sharing scheme based on HLRs(VESIS-(t,s,k,n))

In traditional secret image sharing schemes,a secret image is shared among shareholders who have the same position.But if the shareholders have two different positions,essential and non‐essential,it is necessary to use essential secret image sharing schemes.In this article,a verifiable essential secret image sharing scheme based on HLRs is proposed.Shareholder's share consists of two parts.The first part is produced by the shareholders,which prevents the fraud of dealers.The second part is a shadow image that is produced by using HLRs and the first part of share.The verification of the first part of the shares is done for the first time by using multilinear and bilinear maps.Also,for verifying shadow images,Bloom Filters are used for the first time.The proposed scheme is more efficient than similar schemes,and for the first part of the shares,has formal security.

Risk Factors Associated with Obstetric Perineal Tear in a Maternity Ward of the Communal Medical Center of Ratoma-Conakry-Guinea

Introduction: Obstetric perineal tears are a common complication during childbirth. The objectives of this study were to describe the sociodemographic characteristics, the different types of perineal tears and to identify the associated risk factors. Patients and Method: The maternity of the CMC of Ratoma served as a setting for carrying out this study. This was a prospective study of a descriptive and analytical type, which took place over a period of 6 months from July 1, 2021 to January 1, 2022. Results: The frequency of perineal tear was 9%. The average age of the patients concerned was 23.99 years ± 5.18 years, with extremes of 15 and 38 years. Housewives were the most numerous (30.88%). Most of our parturient had undergone excision (99.6%) and they were more frequently primiparous (40.44%) and pauciparous (47.79%). The multiplicity of risk factors was a remarkable fact (scarred perineum, edematous, short, and infected). The presentation was cephalic in 96.33%, posterior variety in 3.81% and the variety of positions could not be specified by the health worker who provided care to the parturient in 46.56%. The expulsion took place in OP (92.37%) and in OS (2.30%). In most cases, midwives carried out deliveries (93%). Perineal tears were 1st degree (54.41%), 2nd degree (39.70%), 3rd degree (5.15%) and 4th degree (0.74%). Conclusion: Prevention of perineal obstetric injuries is based on better knowledge of risk factors and delivery by qualified personnel. The main limitation of this study is the impossibility of highlighting occult perineal lesions due to the weakness of the technical platform.

Cryptanalysis of efficient semi-quantum secret sharing protocol using single particles

In paper[Chin.Phys.B 32070308(2023)],Xing et al.proposed a semi-quantum secret sharing protocol by using single particles.We study the security of the proposed protocol and find that it is not secure,that is,the three dishonest agents,Bob,Charlie and Emily can collude to obtain Alice's secret without the help of David.

Blockchain-Based Key Management Scheme Using Rational Secret Sharing

Traditional blockchain key management schemes store private keys in the same location,which can easily lead to security issues such as a single point of failure.Therefore,decentralized threshold key management schemes have become a research focus for blockchain private key protection.The security of private keys for blockchain user wallet is highly related to user identity authentication and digital asset security.The threshold blockchain private key management schemes based on verifiable secret sharing have made some progress,but these schemes do not consider participants’self-interested behavior,and require trusted nodes to keep private key fragments,resulting in a narrow application scope and low deployment efficiency,which cannot meet the needs of personal wallet private key escrow and recovery in public blockchains.We design a private key management scheme based on rational secret sharing that considers the self-interest of participants in secret sharing protocols,and constrains the behavior of rational participants through reasonable mechanism design,making it more suitable in distributed scenarios such as the public blockchain.The proposed scheme achieves the escrow and recovery of personal wallet private keys without the participation of trusted nodes,and simulate its implementation on smart contracts.Compared to other existing threshold wallet solutions and keymanagement schemes based on password-protected secret sharing(PPSS),the proposed scheme has a wide range of applications,verifiable private key recovery,low communication overhead,higher computational efficiency when users perform one-time multi-key escrow,no need for trusted nodes,and personal rational constraints and anti-collusion attack capabilities.

Improvement and security analysis of multi-ring discrete modulation continuous variable quantum secret sharing scheme

In order to avoid the complexity of Gaussian modulation and the problem that the traditional point-to-point communication DM-CVQKD protocol cannot meet the demand for multi-user key sharing at the same time, we propose a multi-ring discrete modulation continuous variable quantum key sharing scheme(MR-DM-CVQSS). In this paper, we primarily compare single-ring and multi-ring M-symbol amplitude and phase-shift keying modulations. We analyze their asymptotic key rates against collective attacks and consider the security key rates under finite-size effects. Leveraging the characteristics of discrete modulation, we improve the quantum secret sharing scheme. Non-dealer participants only require simple phase shifters to complete quantum secret sharing. We also provide the general design of the MR-DM-CVQSS protocol.We conduct a comprehensive analysis of the improved protocol's performance, confirming that the enhancement through multi-ring M-PSK allows for longer-distance quantum key distribution. Additionally, it reduces the deployment complexity of the system, thereby increasing the practical value.

Verifiable quantum secret sharing scheme based on orthogonal product states

In the domain of quantum cryptography,the implementation of quantum secret sharing stands as a pivotal element.In this paper,we propose a novel verifiable quantum secret sharing protocol using the d-dimensional product state and Lagrange interpolation techniques.This protocol is initiated by the dealer Alice,who initially prepares a quantum product state,selected from a predefined set of orthogonal product states within the C~d■C~d framework.Subsequently,the participants execute unitary operations on this product state to recover the underlying secret.Furthermore,we subject the protocol to a rigorous security analysis,considering both eavesdropping attacks and potential dishonesty from the participants.Finally,we conduct a comparative analysis of our protocol against existing schemes.Our scheme exhibits economies of scale by exclusively employing quantum product states,thereby realizing significant cost-efficiency advantages.In terms of access structure,we adopt a(t, n)-threshold architecture,a strategic choice that augments the protocol's practicality and suitability for diverse applications.Furthermore,our protocol includes a rigorous integrity verification mechanism to ensure the honesty and reliability of the participants throughout the execution of the protocol.

Effects of counter-current driven by electron cyclotron waves on neoclassical tearing mode suppression

Through theoretical analysis,we construct a physical model that includes the influence of counter-external driven current opposite to the plasma current direction in the neoclassical tearing mode(NTM).The equation is used with this model to obtain the modified Rutherford equation with co-current and counter-current contributions.Consistent with the reported experimental results,numerical simulations have shown that the localized counter external current can only partially suppress NTM when it is far from the resonant magnetic surface.Under some circumstances,the Ohkawa mechanism dominated current drive(OKCD)by electron cyclotron waves can concurrently create both co-current and counter-current.In this instance,the minimal electron cyclotron wave power that suppresses a particular NTM was calculated by the Rutherford equation.The result is marginally less than when taking co-current alone into consideration.As a result,to suppress NTM using OKCD,one only needs to align the co-current with a greater OKCD peak well with the resonant magnetic surface.The effect of its lower counter-current does not need to be considered because the location of the counter-current deviates greatly from the resonant magnetic surface.

Physical-Layer Secret Key Generation for Dual-Task Scenarios

Physical-layer secret key generation(PSKG)provides a lightweight way for group key(GK)sharing between wireless users in large-scale wireless networks.However,most of the existing works in this field consider only group communication.For a commonly dual-task scenario,where both GK and pairwise key(PK)are required,traditional methods are less suitable for direct extension.For the first time,we discover a security issue with traditional methods in dual-task scenarios,which has not previously been recognized.We propose an innovative segment-based key generation method to solve this security issue.We do not directly use PK exclusively to negotiate the GK as traditional methods.Instead,we generate GK and PK separately through segmentation which is the first solution to meet dual-task.We also perform security and rate analysis.It is demonstrated that our method is effective in solving this security issue from an information-theoretic perspective.The rate results of simulation are also consistent with the our rate derivation.