In-situ deposited anti-aging TiN capping layer for Nb superconducting quantum circuits

The performance of Nb superconducting quantum devices is predominantly limited by dielectric loss at the metal–air interface,where Nb2O5 is considered the main loss source.Here,we suppress the formation of native oxides by in-situ deposition of a TiN capping layer on the Nb film.With TiN capping layers,no Nb2O5 forms on the surface of the Nb film.The quality factor Qi of the Nb resonator increases from 5.6×10^(5) to 7.9×10^(5) at low input power and from 6.8×10^(6) to 1.1×10^(7)at high input power.Furthermore,the TiN capping layer also shows good aging resistance in Nb resonator devices,with no significant performance fluctuations after one month of aging.These findings highlight the effectiveness of TiN capping layers in enhancing the performance and longevity of Nb superconducting quantum devices.

Correction of microwave pulse reflection by digital filters in superconducting quantum circuits

Reducing the control error is vital for high-fidelity digital and analog quantum operations.In superconducting circuits,one disagreeable error arises from the reflection of microwave signals due to impedance mismatch in the control chain.Here,we demonstrate a reflection cancelation method when considering that there are two reflection nodes on the control line.We propose to generate the pre-distortion pulse by passing the envelopes of the microwave signal through digital filters,which enables real-time reflection correction when integrated into the field-programmable gate array(FPGA).We achieve a reduction of single-qubit gate infidelity from 0.67%to 0.11%after eliminating microwave reflection.Real-time correction of microwave reflection paves the way for precise control and manipulation of the qubit state and would ultimately enhance the performance of algorithms and simulations executed on quantum processors.

Expression and significance of pigment epithelium-derived factor and vascular endothelial growth factor in colorectal adenoma and cancer

BACKGROUND The incidence and mortality of colorectal cancer(CRC)are among the highest in the world,and its occurrence and development are closely related to tumor neovascularization.When the balance between pigment epithelium-derived factors(PEDF)that inhibit angiogenesis and vascular endothelial growth factors(VEGF)that stimulate angiogenesis is broken,angiogenesis is out of control,resulting in tumor development.Therefore,it is very necessary to find more therapeutic targets for CRC for early intervention and later treatment.AIM To investigate the expression and significance of PEDF,VEGF,and CD31-stained microvessel density values(CD31-MVD)in normal colorectal mucosa,adenoma,and CRC.METHODS In this case-control study,we collected archived wax blocks of specimens from the Digestive Endoscopy Center and the General Surgery Department of Chengdu Second People's Hospital from April 2022 to October 2022.Fifty cases of specimen wax blocks were selected as normal intestinal mucosa confirmed by electronic colonoscopy and concurrent biopsy(normal control group),50 cases of specimen wax blocks were selected as colorectal adenoma confirmed by electronic colonoscopy and pathological biopsy(adenoma group),and 50 cases of specimen wax blocks were selected as CRC confirmed by postoperative pathological biopsy after inpatient operation of general surgery(CRC group).An immunohistochemical staining experiment was carried out to detect PEDF and VEGF expression in three groups of specimens,analyze their differences,study the relationship between the two and clinicopathological factors in CRC group,record CD31-MVD in the three groups,and analyze the correlation of PEDF,VEGF,and CD31-MVD in the colorectal adenoma group and the CRC group.The F test or adjusted F test is used to analyze measurement data statistically.Kruskal-Wallis rank sum test was used between groups for ranked data.The chi-square test,adjusted chi-square test,or Fisher's exact test were used to compare the rates between groups.All differences between groups were compared using the Bonferroni method for multiple comparisons.Spearman correlation analysis was used to test the correlation of the data.The test level(α)was 0.05,and a two-sided P<0.05 was considered statistically significant.RESULTS The positive expression rate and expression intensity of PEDF were gradually decreased in the normal control group,adenoma group,and CRC group(100%vs 78%vs 50%,χ^(2)=34.430,P<0.001;++~++vs+~++vs-~+,H=94.059,P<0.001),while VEGF increased gradually(0%vs 68%vs 96%,χ^(2)=98.35,P<0.001;-vs-~+vs++~+++,H=107.734,P<0.001).In the CRC group,the positive expression rate of PEDF decreased with the increase of differen-tiation degree,invasion depth,lymph node metastasis,distant metastasis,and TNM stage(χ^(2)=20.513,4.160,5.128,6.349,5.128,P<0.05);the high expression rate of VEGF was the opposite(χ^(2)=10.317,13.134,17.643,21.844,17.643,P<0.05).In the colorectal adenoma group,the expression intensity of PEDF correlated negatively with CD31-MVD(r=-0.601,P<0.001),whereas VEGF was not significantly different(r=0.258,P=0.07).In the CRC group,the expression intensity of PEDF correlated negatively with the expression intensity of CD31-MVD and VEGF(r=-0.297,P<0.05;r=-0.548,P<0.05),while VEGF expression intensity was positively related to CD31-MVD(r=0.421,P=0.002).CONCLUSION It is possible that PEDF can be used as a new treatment and prevention target for CRC by upregulating the expression of PEDF while inhibiting the expression of VEGF.

Atypical Guillain-Barrésyndrome with positive anti-sulfatide,anti-GT1b,and anti-GT1a antibodies:A case report

BACKGROUND The role of diverse antibodies in mediating peripheral nerve injury in Guillain-Barrésyndrome(GBS)is becoming clearer,but positivity for multiple antibodies in one case is uncommon.To our knowledge,this is the first case involving GBS with positive anti-sulfatide,anti-GT1a,and anti-GT1b antibodies.CASE SUMMARY A 20-year-old female patient was admitted to the hospital due to weakness of limbs for 5 d,and deterioration of the weakness and muscle aches for 1 d.The patient's limbs were weak,but the tendon reflexes in the part of the limbs were normal.There was no comorbid peripheral nociception or deep sensory dysfunction.She was diagnosed with GBS and was discharged after receiving intravenous human immunoglobulin pulse therapy.CONCLUSION In this article,the clinical manifestations,neurophysiological examination,and auxiliary examination findings of a GBS patient positive for multiple antibodies were analyzed to improve the identification of the disease by clinical physicians at an early stage.

瑞芬太尼与舒芬太尼靶控输注对老年患者行腹腔镜胃癌根治术麻醉恢复质量的影响

目的比较靶控输注瑞芬太尼和舒芬太尼对老年患者行腹腔镜胃癌根治术麻醉恢复的质量。方法选取2016年9月-2018年12月该院腹腔镜胃癌根治术患者84例,随机分为舒芬太尼组(n=42)和瑞芬太尼组(n=42)。两组患者应用靶控输注舒芬太尼和瑞芬太尼为基础的麻醉。记录并比较两组患者唤醒时间、拔管时间、定向力恢复时间、生命体征、应激反应、T细胞亚群分布及不良反应发生率。结果两组患者定向力恢复时间差异无统计学意义(P>0.05)。舒芬太尼组的清醒和拔管时间明显短于瑞芬太尼组,差异均有统计学意义(P<0.05)。舒芬太尼组麻醉结束、麻醉诱导后和麻醉前的心率(HR)、平均动脉压(MAP)和脉搏血氧饱和度(SpO2)比较,差异均无统计学意义(P>0.05),而瑞芬太尼组麻醉结束、麻醉诱导后和麻醉前的HR、MAP和SpO2比较,差异均有统计学意义(P<0.05)。舒芬太尼组在麻醉后、麻醉结束、麻醉结束24 h和麻醉结束72 h 4个时间点,血葡萄糖(GLU)、皮质醇(Cor)、白细胞介素-6(IL-6)和C反应蛋白(CRP)的浓度均明显低于瑞芬太尼组,CD3^+、CD4^+和CD8^+及CD4+/CD8^+明显高于瑞芬太尼组,瑞芬太尼组麻醉不良反应发生率明显高于舒芬太尼组,差异有统计学意义(P<0.05)。结论对于接受腹腔镜胃癌根治术的老年患者,靶控输注舒芬太尼为基础的麻醉具有麻醉过程平稳、应激反应小、抑制细胞免疫轻和不良反应少等优点,值得临床推广。

Comparative analysis of intestinal microbial community diversity between healthy and orally infected ducklings with Salmonella enteritidis by ERIC-PCR

AIM: To analyze the difference of intestinal microbial community diversity between healthy and (S. enteritidis) orally infected ducklings.METHODS: Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR was applied to analyze the intestinal microbial community diversity and dynamic change including duodenum, jejunum, ileum, cecum and rectum from healthy ducklings and 7-day-old ducklings after oral infection with S. enteritidis at different time points.RESULTS: The intestinal microbial community of the control healthy ducklings was steady and the ERIC-PCR band numbers of the control healthy ducklings were the least with rectum and were the most with caecum. ERIC-PCR bands of orally inoculated ducklings did not obviously change until 24 h after inoculation (p.i.). The numbers of the ERIC-PCR bands gradually decreased from 24 h to 72 h p.i., and then, with the development of disease, the band numbers gradually increased until 6 d p.i. The prominent bacteria changed because of S. enteritidis infection and the DNAstar of staple of ERIC-PCR showed that aerobe and facultative aerobe (Escherichia coli, Shigella, Salmonella) became preponderant bacilli in the intestine of orally infected ducklings with SE.CONCLUSION: This study has provided significant data to clarify the intestinal microbial community diversity and dynamic change of healthy and S. enteritidis orally infected ducklings, and valuable insight into the pathogenesis of S. enteritidis infection in both human and animals.

Arterial embolism caused by a peripherally inserted central catheter in a very premature infant:A case report and literature review

BACKGROUND Extremely premature infants have poor vascular conditions.Operators often choose deep veins such as the femoral vein and axillary vein to peripherally insert central catheters,and these vessels are often accompanied by arteries;thus,it is easy to mistakenly enter the artery.CASE SUMMARY The case of an extremely premature infant(born at gestational age 28+3)in whom the left upper extremity artery was accidentally entered during peripheral puncture of the central venous catheter is reported.On the 19th day of hospitalization,the index finger,middle finger and ring finger of the left hand were rosy,the left radial artery and brachial artery pulse were palpable,the recovery was 95%,and the improvement was obvious.At discharge 42 d after admission,there was no abnormality in fingertip activity during the follow-up period.CONCLUSION Arterial embolization in preterm infants requires an individualized treatment strategy combined with local anticoagulation and 2%nitroglycerin ointment for local tissue damage caused by arterial embolism in the upper limb.Continuous visualization of disease changes using image visualization increases the likelihood of a good outcome.

Three New Humulane Sesquiterpenes from Cultures of the Fungus Antrodiella albocinnamomea

Three new humulane-type sesquiterpenes,antrodols A–C(1–3),were isolated from cultures of the fungus Antrodiella albocinnamomea.Their structures were elucidated on the basis of extensive spectroscopic analysis.Antrodols A–C(1–3)are first examples of humulane-type sesquiterpenes isolated from cultures of higher fungi,and antrodol A(1)was the first report of humulane-type sesquiterpene with a methyl rearranged at C-3.All compounds were evaluated in the enzyme inhibition assay against two protein-tyrosine phosphatases(PTPs):MEG2 and PTP1Bc.

Two new drimane sesquiterpenoids from cultures of the basidiomycete Trichaptum biforme

Two new drimane sesquiterpenoids(1 and 2),as well as five known compounds(3-7),were isolated from the basidiomycete Trichaptum biforme.The structures of new compounds were elucidated by extensive spectroscopic methods,and the known compounds were identified by comparing their spectroscopic data with those reported in the literature.The cytotoxicities results against five human cancer cell lines of compounds 1 and 2 were negligible.

Wavelength dependence of intrinsic detection efficiency of NbN superconducting nanowire single-photon detector

Superconducting nanowire single-photon detectors(SNSPDs) have attracted considerable attention owing to their excellent detection performance;however, the underlying physics of the detection process is still unclear.In this study, we investigate the wavelength dependence of the intrinsic detection efficiency(IDE) for NbN SNSPDs.We fabricate various NbN SNSPDs with linewidths ranging from 30 nm to 140 nm.Then, for each detector, the IDE curves as a function of bias current for different incident photon wavelengths of 510–1700 nm are obtained.From the IDE curves, the relations between photon energy and bias current at a certain IDE are extracted.The results exhibit clear nonlinear energy–current relations for the NbN detectors, indicating that a detection model only considering quasiparticle diffusion is unsuitable for the meander-type NbN-based SNSPDs.Our work provides additional experimental data on SNSPD detection mechanism and may serve as an interesting reference for further investigation.

Successful treatment of pulmonary hypertension in a neonate with bronchopulmonary dysplasia: A case report and literature review

BACKGROUND Pulmonary hypertension(PH)is a severe complication of bronchopulmonary dysplasia(BPD)in premature neonates and is closely related to prognosis.However,there is no effective and safe treatment for PH due to BPD in infants.Successful treatment for cases of BPD-associated PH with Tadalafil combined with bosentan is rare.This case may make a significant contribution to the literature because PH is difficult to manage as a serious complication of BPD in preterm infants.Mortality is high,especially when it is complicated by heart failure.CASE SUMMARY An extremely premature neonate with a gestational age of 26+5 wk and birth weight of 0.83 kg was diagnosed with BPD associated with PH;oral sildenafil did not improve the PH.The infant experienced sudden cardiac arrest and serious heart failure with severe PH.After a series of treatments,including cardiopulmonary resuscitation,mechanical ventilation,and inhaled nitric oxide(iNO),the respiratory and circulatory status improved but the pulmonary artery pressure remained high.Then oral sildenafil was replaced with oral tadalafil and bosentan;pulmonary artery pressure improved,and the infant recovered at our hospital.After 2 years of follow-up,she is in good condition,without any cardiovascular complications.CONCLUSION INO can effectively improve the respiratory and circulatory status of infants with PH associated with premature BPD.B-type natriuretic peptide should be routinely measured during hospitalization to evaluate the risk and prognosis of BPD-associated PH in preterm infants.Tadalafil combined with bosentan for the treatment of PH associated with premature BPD was better than sildenafil in this case.Further studies are needed to explore the efficacy and safety of different vasodilators in the treatment of PH associated with premature BPD.

Fast and perfect state transfer in superconducting circuit with tunable coupler

In quantum computation and quantum information processing, the manipulation and engineering of quantum systems to suit certain purposes are an ongoing task. One such example is quantum state transfer(QST), an essential requirement for both quantum communication and large-scale quantum computation. Here we engineer a chain of four superconducting qubits with tunable couplers to realize the perfect state transfer(PST) protocol originally proposed in quantum spin networks and successfully demonstrate the efficient transfer of an arbitrary single-qubit state from one end of the chain to the other,achieving a high fidelity of 0.986 in just 25 ns. This demonstrated QST is readily to extend to larger chain and multi-node configurations, thus serving as a desirable tool for scalable quantum information processing.

Photon number resolvability of multi-pixel superconducting nanowire single photon detectors using a single flux quantum circuit

Superconducting nanowire single-photon detectors(SNSPDs) are typical switching devices capable of detecting single photons with almost 100% detection efficiency. However, they cannot determine the exact number of incident photons during a detection event. Multi-pixel SNSPDs employing multiple read-out channels can provide photon number resolvability(PNR), but they require increased cooling power and costly multi-channel electronic systems. In this work, a single-flux quantum(SFQ) circuit is employed, and PNR based on multi-pixel SNSPDs is successfully demonstrated. A multi-input magnetically coupled DC/SFQ converter(MMD2 Q) circuit with a mutual inductance M is used to combine and record signals from a multi-pixel SNSPD device. The designed circuit is capable of discriminating the amplitude of the combined signals in accuracy of Φ_(0)/M with Φ_(0) being a single magnetic flux quantum. By employing the MMD2 Q circuit,the discrimination of up to 40 photons can be simulated. A 4-parallel-input MMD2 Q circuit is fabricated, and a PNR of3 is successfully demonstrated for an SNSPD array with one channel reserved for the functional verification. The results confirm that an MMD2 Q circuit is an effective tool for implementing PNR with multi-pixel SNSPDs.

Five new 5,6-seco-tremulane sesquiterpenoids from the basidiomycete Conocybe siliginea

Five new 5,6-seco-tremulane sesquiterpenoids(1-5),as well as three known analogues(6-8),were isolated from the basidiomycete Conocybe siliginea.The structures of new compounds were elucidated by extensive spectroscopic methods.The known compounds were identified by comparing their spectroscopic data with those reported in the literature.

Clinical control effect analysis of intravenous infusion of lidocaine and dexmedetomidine for prevention and treatment of CRBD

Objective To investigate the clinical value of intravenous lidocaine in reducing CRBD in male patients who need catheterization after general anesthesia.Methods A total of 210 male patients who underwent elective general anesthesia in our hospital from May 2017 to April 2018 were selected.Random number table method was used to divide into the lidocaine group(1.5 mg?kg-1 of intravenous lidocaine infusion during anesthesia induction,and continuous intravenous infusion of lidocaine 2 mg?kg-1?h-1 after intubation),Dexmedetomidine group(0.5μg?kg-1 of dexmedetomidine intravenously during anesthesia induction,continuous intravenous infusion of dexmedetomidine 0.4μg?kg-1?h-1 after intubation).Control group(intravenous saline infusion during anesthesia induction,continuous intravenous infusion of the same amount of saline after intubation),70 cases in each group.All three groups were placed in the bladder with a 16F comfortable urethral catheter lubricated with paraffin oil.The amount of sufentanil used during the operation,the amount of sufentanil used after surgery,and the CRBD score and VAS at different time points after extubation were compared.Scoring,HR,SBP.Results T1 to T4,the CRBD scores of the lidocaine group were lower than those of the dexmedetomidine group and the control group(P<0.05).The VAS scores of the lidocaine group were lower than those of the control group(P<0.05),the CRBD score and VAS score of the dexmedetomidine group were lower than those of the control group(P<0.05);From T0 to T4,the differences in HR and SBP between the three groups were not statistically significant(P>0.05).Conclusion Lidocaine administration in male patients requiring catheterization after general anesthesia can significantly reduce the incidence of CRBD.

Congenital leukemia: A case report and review of literature

BACKGROUND Acute leukemia in newborns is also known as neonatal or congenital leukemia(CL)and is a rare disease with an incidence rate of 1-5 per 1000000 live births.After birth,infants with CL exhibit infiltrative cutaneous nodules,hepatosplenomegaly,thrombocytopenia,and immature leukocytes in the peripheral blood.These symptoms are frequently accompanied by congenital abnormalities including trisomy 21,trisomy 9,trisomy 13,or Turner syndrome.Despite significant advances in disease management,the survival rate is approximately 25%at 2 years.CASE SUMMARY Here,we document a case of trisomy 21-related acute myeloid leukemia(AML)in a female neonate.The baby was sent to the neonatal intensive care unit because of anorexia,poor responsiveness,and respiratory distress.She was diagnosed with AML based on bone marrow aspiration and immunophenotyping.Genetic sequencing identified a mutation in the GATA1 gene.After receiving the diagnosis,the parents decided against medical care for their child,and the baby died at home on day 9 after birth.CONCLUSIONS The newborn infant was diagnosed with trisomy 21-related AML.Genetic sequencing identified a mutation in the GATA1 gene.The parents abandoned medical treatment for their infant after receiving the diagnosis,and the infant died at home on the 9th day after birth.

Research On Construction Traffic Safety Measures Based On FAHP Model In Hydropower Project

With the rapid expansion of hydropower projects, Construction safety problem has become one of the bottlenecks for the development of hydropower industry. Combined with the construction of the diversion channel project of Guan Yinyan hydropower station, from the point of view of construction traffic safety, based on the result of the FAHP model, factors which influence the construction safety of the diversion channel project of Guan Yinyan hydropower station have been found, relative measures focuses on the approach to eliminate hazards and guarantee construction safety have been elaborated.

Study on the mechanism of microporous sheep ADM combined with hUCMSC in promoting wound healing

Objective:To explore the therapeutic mechanism of microporous sheep acellular dermal matrix(ADM)combined with human umbilical cord mesenchymal stem cell(hUCMSC)to promote the healing of full-thickness skin defect.Methods:hUCMSC was co-cultured on microporous sheep ADM to form composite biological dressings.Seventy-two nude mice were selected to make full-thickness skin injury models and randomly divided into 3 groups(hUCMSC+microporous sheep ADM group,sheep ADM group and iodophor gauze group),with 24 mice in each group.The wound healing rate of each group was detected at 14 d,21 d and 28 d after operation,qRT-PCR technique was used to detect the expression of Bax and Bcl-2 in the wound tissues,and the immunohistochemical staining technique was used to detect the expression of Collagen I and vascular endothelial growth factor(VEGF).Data were analyzed with one-way ANOVA and t test.Results:At 14 d after operation,the wound healing rate of the hUCMSC+microporous sheep ADM group was(65.34±14.72)%,which was significantly higher than that of the iodophor gauze group[(37.54±10.21)%],and higher than that of the sheep ADM group[(49.08±11.16)%],the differences were statistically significant(t=19.52,14.72;p<.05).With the gradual healing of the wound,at 28 d after operation,the wound healing rate of the hUCMSC+microporous sheep ADM group was(98.63±15.41)%,which was significantly higher than that of the iodophor gauze group[(81.74±16.27)%],and higher than that of the sheep ADM group[(63.47±14.80)%],the differences were statistically significant(t=-16.42,20.35;p<.05).The expression of Bax in the wound tissues of the hUCMSC+microporous sheep ADM group was significantly reduced,especially at 21 d after operation,the expression level was 0.25±0.06,which was significantly lower than the iodophor gauze group(0.53±0.16)and the sheep ADM group(0.41±0.12),the differences were statistically significant(t=3.52,-2.83;p<.05).The expression of Bcl-2 in the wound tissues of the hUCMSC+microporous sheep ADM group was significantly higher than those of the other two groups,especially at 21 d after operation,the expression level was 0.63±0.19,which was significantly higher than the iodophor gauze group(0.34±0.09)and the sheep ADM group(0.46±0.13),the differences were statistically significant(t=5.31,-6.07;p<.05).Immunohistochemical detection showed that the expression of Collagen I and VEGF in the hUCMSC+microporous sheep ADM group was slightly more than that of the sheep ADM group and the iodophor gauze group,but the effect was not remarkable.Conclusions:hUCMSC+microporous sheep ADM composite dressing can promote the healing of the full-thickness skin injury and reduce the production of apoptotic cells by carrying hUCMSC.

Sirolimus can promote the disappearance of renal angiomyolipoma associated with tuberous sclerosis complex:a prospective cohort study

Background Renal angiomyolipoma(RAML)is the most common kidney lesion in patients with tuberous sclerosis complex(TSC),affecting about 80%of patients.It is a benign tumor that grows over time,usually bilaterally,and can easily lead to kidney complications such as acute hemorrhage.Herein,we investigated the efficacy and safety of sirolimus in children with TSC-associated RAML and explored the factors affecting tumor disappearance under sirolimus treatment through subgroup analysis.Methods A prospective cohort study was conducted.Sirolimus was initiated at 1 mg/(m^(2)×day),and dose adjustments were made by a 2-week titration period to attain a trough blood concentration of 5-10 ng/mL.The disappearance of RAML in chil-dren after sirolimus treatment was observed,and Cox regression was used to screen the factors affecting tumor disappearance.Results One hundred and twenty-six patients who met the criteria were analyzed.After 3 months,6 months,12 months,and 24 months of follow-up,tumors disappeared in 18(14.3%),30(23.8%),39(31.0%),and 42(33.3%)children,respec-tively.Tumors disappeared in 50(39.7%)children by the last visit of each individual,and 30(60%)of them occurred within 6 months.The multivariate Cox regression analysis showed that patients with a smaller maximum tumor diameter at baseline had a higher tumor disappearance rate.Thirty-six(29%)patients had stomatitis during the entire treatment period,and no serious adversereactionswereobserved.Conclusions Sirolimus could promote the disappearance of TSC-related RAML.The disappearance rate was correlated with the maximum diameter at baseline,and the smaller the tumor was,the higher the disappearance rate.It is well tolerated in the treatment of RAML associated with TSC.

Coupled dynamic response analysis of multi-column floating offshore wind turbine with low center of gravity

To realize the application of the floating offshore wind turbine(FOWT)from deep to relatively shallow waters,a new concept of multi-column floating wind turbine platform with low center of gravity(CG)is designed and validated.The multi-column low CG platform is designed to support a 6MW wind turbine class and operated at a water depth of 50m in the South China Sea.The frequency domain software WADAM and time domain software NREL-FAST are used to simulate coupled dynamic responses of the floating wind turbine system with second-order wave loads considering.The dynamic behaviors of multi-column low CG FOWT system under normal operation and parked conditions are presented.The influence of second-order wave force on the motion responses of the multi-column platform,fore-aft force and moment of the tower base and mooring force are researched respectively.The results demonstrate that the coupled dynamic responses at rated operating condition and extreme condition meet the normal operating requirements and extreme survival requirements of FOWT system in the shallow water(50m)of South China Sea.In addition,it is found that,the wave frequency response gradually replaces the second-order low frequency response as the main influencing factor of the coupled dynamic response of the FOWT system with the increasing severity of the sea states.However,in general,the magnitude of second-order low frequency response increases with the increasing severity of the design load case.Thus,in the subsequent design of the shallow water FOWT system,the second-order effects should be paid enough attention.