Computed tomography radiogenomics:A potential tool for prediction of molecular subtypes in gastric stromal tumor

BACKGROUND Preoperative knowledge of mutational status of gastrointestinal stromal tumors(GISTs)is essential to guide the individualized precision therapy.AIM To develop a combined model that integrates clinical and contrast-enhanced computed tomography(CE-CT)features to predict gastric GISTs with specific genetic mutations,namely KIT exon 11 mutations or KIT exon 11 codons 557-558 deletions.METHODS A total of 231 GIST patients with definitive genetic phenotypes were divided into a training dataset and a validation dataset in a 7:3 ratio.The models were constructed using selected clinical features,conventional CT features,and radiomics features extracted from abdominal CE-CT images.Three models were developed:ModelCT sign,modelCT sign+rad,and model CTsign+rad+clinic.The diagnostic performance of these models was evaluated using receiver operating characteristic(ROC)curve analysis and the Delong test.RESULTS The ROC analyses revealed that in the training cohort,the area under the curve(AUC)values for model_(CT sign),model_(CT sign+rad),and modelCT_(sign+rad+clinic)for predicting KIT exon 11 mutation were 0.743,0.818,and 0.915,respectively.In the validation cohort,the AUC values for the same models were 0.670,0.781,and 0.811,respectively.For predicting KIT exon 11 codons 557-558 deletions,the AUC values in the training cohort were 0.667,0.842,and 0.720 for model_(CT sign),model_(CT sign+rad),and modelCT_(sign+rad+clinic),respectively.In the validation cohort,the AUC values for the same models were 0.610,0.782,and 0.795,respectively.Based on the decision curve analysis,it was determined that the model_(CT sign+rad+clinic)had clinical significance and utility.CONCLUSION Our findings demonstrate that the combined modelCT_(sign+rad+clinic)effectively distinguishes GISTs with KIT exon 11 mutation and KIT exon 11 codons 557-558 deletions.This combined model has the potential to be valuable in assessing the genotype of GISTs.

Comparison between air and carbon dioxide insufflation in the endoscopic submucosal excavation of gastrointestinal stromal tumors

AIM:To evaluate the safety and efficacy of CO2 insufflation compared with air insufflation in the endoscopic submucosal excavation(ESE) of gastrointestinal stromal tumors.METHODS:Sixty patients were randomized to undergo endoscopic submucosal excavation,with the CO2 group(n = 30) and the air group(n = 30) undergoingCO2 insufflation and air insufflation in the ESE,respectively.The end-tidal CO2 level(pETCO2) was observed at 4 time points:at the beginning of ESE,at total removal of the tumors,at completed wound management,and 10 min after ESE.Additionally,the patients' experience of pain at 1,3,6 and 24 h after the examination was registered using a visual analog scale(VAS).RESULTS:Both the CO2 group and air group were similar in mean age,sex,body mass index(all P > 0.05).There were no significant differences in PetCO2 values before and after the procedure(P > 0.05).However,the pain scores after the ESE at different time points in the CO2 group decreased significantly compared with the air group(1 h:21.2 ± 3.4 vs 61.5 ± 1.7;3 h:8.5 ± 0.7 vs 42.9 ± 1.3;6 h:4.4 ± 1.6 vs 27.6 ± 1.2;24 h:2.3 ± 0.4 vs 21.4 ± 0.7,P < 0.05).Meanwhile,the percentage of VAS scores of 0 in the CO2 group after 1,3,6 and 24 h was significantly higher than that in the air group(60.7 ± 1.4 vs 18.9 ± 1.5,81.5 ± 2.3 vs 20.6 ± 1.2,89.2 ± 0.7 vs 36.8 ± 0.9,91.3 ± 0.8 vs 63.8 ± 1.3,respectively,P < 0.05).Moreover,the condition of the CO2 group was better than that of the air group with respect to anal exsufflation.CONCLUSION:Insufflation of CO2 in the ESE of gastrointestinal stromal tumors will not cause CO2 retention and it may significantly reduce the level of pain,thus it is safe and effective.

Co-infection of SARS-COV-2 and Influenza A Virus:A Case Series and Fast Review

Coronavirus disease 2019(COVID-19)occurs in the influenza season and has become a global pandemic.The present study aimed to examine severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)co-infection with influenza A virus(IAV)in an attempt to provide clues for the antiviral interventions of co-infected patients.We described two patients who were co-infected with SARS-CoV-2 and IAV treated at Wuhan Union Hospital,China.In addition,we performed a review in PubMed,Web of Science and CNKI(from January 1 up to November 1,2020)with combinations of the following key words:“COVID-19,SARS-COV-2,influenza A and co-infection”.A total of 28 co-infected patients were enrolled in the analysis.Of the 28 patients,the median age was 54.5 years(IQR,34.25–67.5)and 14 cases(50.0%)were classified as severe types.The most common symptoms were fever(85.71%),cough(82.14%)and dyspnea(60.71%).Sixteen patients had lymphocytopenia on admission and 23 patients exhibited abnormal radiological changes.The median time from symptom onset to hospital admission was 4 days(IQR,3–6),and the median time of hospital stay was 14 days(IQR,8.5–16.75).In conclusion,patients with SARSCOV-2 and IAV co-infection were similar to those infected with SARS-COV-2 alone in symptoms and radiological images.SARS-COV-2 co-infection with IAV could lead to more severe clinical condition but did not experience longer hospital stay compared with patients infected with SARSCOV-2 alone.

Prediction of T cell and B cell epitopes of the 22-, 47-, 56-, and 58-kDa proteins of Orientia tsutsugamushi

Objective:To predict B cell and T cell epitopes of 22-kDa,47-kDa,56-kDa and 58-kDa proteins.Methods:The sequences of 22-kDa,47-kDa,56-kDa and 58-kDa proteins which were derived from Orientia tsutsugamushi were analyzed by SOPMA,DNAstar,Bcepred,ABCpred,NetMHC,NetMHCⅡand IEDB.The 58-kDa tertiary structure model was built by MODELLER9.17.Results:The 22-kDa B-cell epitopes were located at positions 194-200,20-26 and 143-154,whereas the T-cell epitopes were located at positions 154-174,95-107,17-25 and 57-65.The 47-kD a protein B-cell epitopes were at positions 413-434,150-161 and 283-322,whereas the T-cell epitopes were located at positions 129-147,259-267,412-420 and 80-88.The 56-kDa protein B-cell epitopes were at positions 167-173,410-419 and 101-108,whereas the T-cell epitopes were located at positions 88-104,429-439,232-240 and 194-202.The 58-kDa protein B-cell epitopes were at positions 312-317,540-548 and 35-55,whereas the T-cell epitopes were located at positions 415-434,66-84 and 214-230.Conclusions:We identified candidate epitopes of 22-kDa,47-kDa,56-kDa and 58-kDa proteins from Orientia tsutsugamushi.In the case of 58-kDa,the dominant antigen is displayed on tertiary structure by homology modeling.Our findings will help target additional recombinant antigens with strong specificity,high sensitivity,and stable expression and will aid in their isolation and purification.

Robotic-assisted resection of ovarian tumors in children: A case report and review of literature

BACKGROUND Ovarian tumors are common gynecological diseases in children,and the most commonly seen ovarian tumors are germ cell tumors.Robotic surgery is the new access for children ovarian tumors.CASE SUMMARY From June to October 2017,4 children with ovarian tumors were admitted and treated in the Department of Pediatric Surgery of People’s Liberation Army General Hospital.The mean age,height,and weight of these patients were 7.5 (1- 13) years old,123.75 (71-164) cm,and 36.8 (8.5-69.5) kg,respectively.Roboticassisted resection of ovarian tumors was performed for all 4 patients.The 3-port approach was used for robotic manipulation.The surgical procedures were as follows.After creation of the pneumoperitoneum,the robotic scope was placed to explore and find the left ovarian tumor.The trocars for robotic arms 1 and 2 were placed at the sites to the lower right and left of the port of the scope.The tumor capsule in the fallopian tube was incised,and the tumor was completely stripped by an electric hook along the junction of the tumor and the capsule.The resected tumor was completely removed using an endobag.The average docking time of the robotic system was 18.5 min,the average operative time was 120 min,and the average blood loss was 20 mL.No drainage tube was placed except in one patient with a mucinous tumor of the ovary.No fever,pelvic fluid,or intestinal obstruction was reported after surgery.No antibiotics were used during the perioperative period,and the average length of hospital stay after surgery was 3 CONCLUSION Robotic-assisted resection of ovarian tumors is a simple,safe,and effective surgical procedure for selected patients.

Explicit Symplectic Geometric Algorithms for Quaternion Kinematical Differential Equation

Solving quaternion kinematical differential equations(QKDE) is one of the most significant problems in the automation, navigation, aerospace and aeronautics literatures. Most existing approaches for this problem neither preserve the norm of quaternions nor avoid errors accumulated in the sense of long term time. We present explicit symplectic geometric algorithms to deal with the quaternion kinematical differential equation by modelling its time-invariant and time-varying versions with Hamiltonian systems and adopting a three-step strategy. Firstly,a generalized Euler's formula and Cayley-Euler formula are proved and used to construct symplectic single-step transition operators via the centered implicit Euler scheme for autonomous Hamiltonian system. Secondly, the symplecticity, orthogonality and invertibility of the symplectic transition operators are proved rigorously. Finally, the explicit symplectic geometric algorithm for the time-varying quaternion kinematical differential equation, i.e., a non-autonomous and non-linear Hamiltonian system essentially, is designed with the theorems proved. Our novel algorithms have simple structures, linear time complexity and constant space complexity of computation. The correctness and efficiencies of the proposed algorithms are verified and validated via numerical simulations.

Retroperitoneoscopic approach for partial nephrectomy in children with duplex kidney: A case report

BACKGROUND Renal duplication is a common deformity of the urinary system,with an incidence of approximately 1/125 in children.Symptomatic patients with hydronephrosis,vesicoureteral reflux,or incontinence may require surgical interventions.Laparoscopy and retroperitoneoscopy are the two main accesses for partial nephrectomy.CASE SUMMARY A 9-year-old child was admitted to the hospital for hydronephrosis of the left kidney.Ultrasonography showed that the left kidney was larger,approximately 12.6 cm×6.3 cm×5.5 cm in size,with visible separation of the pelvis and an obviously separated lower portion.The upper segment of the left ureter was dilated(approximately 2.6 cm in width),and no significant dilation was observed in the middle and upper segments.The right kidney and ureter were normal.Primary diagnosis was left renal duplication malformation and hydronephrosis.Retroperitoneal laparoscopic nephrectomy and ureterectomy were performed.Intraoperative exploration revealed a dilated pelvis and thin renal parenchyma at the lower pole of the left kidney.The upper left kidney was smaller than normal,and the pelvis and ureter were larger than normal.The renal artery was blocked for 40 min.A hemolock was used to clamp down the kidney ureter,and a drainage tube was retained in the retroperitoneal cavity.The operation was uneventful,and the estimated amount of blood loss was 100 mL.Total abdominal drainage amount was 116 mL.The drainage tube was removed on postoperative day(POD)3 and the patient was discharged on POD6.The pathological diagnosis confirmed the atrophy of the renal parenchyma,the dilation of the renal pelvis,hydronephrosis,and ureteral cystic dilation.CONCLUSION The retroperitoneoscopic approach for partial nephrectomy is feasible and effective in selective pediatric patients with a duplex kidney.

Bufferless Epitaxial Growth of GaAs on Step-Free Ge(001)Mesa

GaAs/Ge heterostructures have been employed in various semiconductor devices such as solar cells,high-performance CMOS transistors,andⅢ-Ⅴ/Ⅳheterogeneous optoelectronic devices.The performance of these devices is directly dependent on the material quality of the GaAs/Ge heterostructure,while the material quality of the epitaxial GaAs layer on the Ge is limited by issues such as the antiphase domain(APD),and stacking-fault pyramids(SFP).We investigate the epitaxial growth of high-quality GaAs on a Ge(001)mesa array,via molecular beam epitaxy.Following a systematic study of the Ge terrace via an in situ scanning tunneling microscope,an atomically step-free terrace on the Ge mesa measuring up to 5×5μm^(2) is obtained,under optimized growth conditions.The step-free terrace has a single-phase c(4×2)surface reconstruction.The deposition of a high-quality GaAs layer with no APD and SFP is then achieved on this step-free Ge terrace.High-resolution transmission electron microscopy and electron channel contrast image characterizations reveal the defect-free growth of the GaAs layer on the step-free Ge mesa.Furthermore,InAs quantum dots on this GaAs/Ge mesa reveal photoluminescent intensity comparable to that achieved on a GaAs substrate,which further confirms the high quality of the GaAs layer on Ge.

Monolithic integration of embedded Ⅲ-Ⅴ lasers on SOI

Silicon photonic integration has gained great success in many application fields owing to the excellent optical device properties and complementary metal-oxide semiconductor(CMOS)compatibility.Realizing monolithic integration of Ⅲ-Ⅴ lasers and silicon photonic components on single silicon wafer is recognized as a long-standing obstacle for ultradense photonic integration,which can provide considerable economical,energy-efficient and foundry-scalable onchip light sources,that has not been reported yet.Here,we demonstrate embedded InAs/GaAs quantum dot(QD)lasers directly grown on trenched silicon-on-insulator(SOI)substrate,enabling monolithic integration with buttcoupled silicon waveguides.By utilizing the patterned grating structures inside pre-defined SOI trenches and unique epitaxial method via hybrid molecular beam epitaxy(MBE),high-performance embedded InAs QD lasers with monolithically out-coupled silicon waveguide are achieved on such template.By resolving the epitaxy and fabrication challenges in such monolithic integrated architecture,embedded Ⅲ-Ⅴ lasers on SOI with continuous-wave lasing up to 85°C are obtained.The maximum output power of 6.8mW can be measured from the end tip of the butt-coupled silicon waveguides,with estimated coupling efficiency of approximately-6.7 dB.The results presented here provide a scalable and low-cost epitaxial method for the realization of on-chip light sources directly coupling to the silicon photonic components for future high-density photonic integration.

Azobenzene Based Photo-responsive Mechanical Actuator Fabricated by Intermolecular H-bond Interaction

Photo-responsive mechanical actuator is a class of stimuli-responsive materials transferring light to mechanical energy through macroscopic transformation.To fabricate photo-responsive mechanical actuator,soft polymeric materials crosslinked with functional bridging structures are desired.Supramolecular interaction is a relatively common way to fabricate crosslinked materials due to its excellent self-assembly performance.And azobenzene and derivatives are ideal candidates of photo-responsive materials because of the unique photo-induced trans-cis isomerization.Here,a new kind of crosslinked materials based on supramolecular interaction between 4,4'-dihydroxyazobenzene and chitosan is reported.Under 355 nm irradiation,the macroscopic bending of polymeric materials occurs rapidly due to the photo-isomerization of 4,4-dihydroxyazobenzene.Meanwhile,the photo-responsive mechanical actuator can also lift weight which is up to 200 times that of the actuator itself,and convert energy from light to mechanical work efficiently.This report suggests a new kind of photo-responsive actuator based on supramolecular interaction and may be helpful to contribute a theoretical basis to the design and synthesis of photo-responsive mechanical actuator suitable for large-scale manufacturing industrialization in future.

Multi-wavelength injection locked semiconductor comb laser

Quantum dot lasers on silicon have gained significant interest over the past decade due to their great potential as an on-chip silicon photonic light source. Here, we demonstrate multi-wavelength injection locking of In As/Ga As quantum dot Fabry–Perot(FP) lasers both on Ga As and silicon substrates by optical self-injection via an external cavity. The number of locked laser modes can be adjusted from a single peak to multiple peaks by tuning wavelength dependent phase and mode spacing of back-injected light through a Lyot filter. The multi-wavelength injection locked laser modes exhibit average optical linewidth of ~20 k Hz, which are narrowed by approximately three orders of magnitude from their free-running condition. Furthermore, multi-wavelength self-injection locking via an external cavity exhibits flat-top optical spectral properties with approximately 30 stably locked channels under stable operation over time, where the frequency detuning is less than 700 MHz within 40 min. Particularly,FP lasers by direct epitaxial growth on silicon substrates are self-injection locked as a flat-top comb source with tunable free spectral range from approximately 25 to 700 GHz. The reported results emphasize the great potential of multi-wavelength injection locked lasers as tunable on-chip multi-wavelength light sources.

Ultra-broadband flat-top quantum dot comb lasers

A quantum dot(QD)mode-locked laser as an active comb generator takes advantage of its small footprint,low power consumption,large optical bandwidth,and high-temperature stability,which is an ideal multi-wavelength source for applications such as datacom,optical interconnects,and LIDAR.In this work,we report a fourth-order colliding pulse mode-locked laser(CPML)based on InAs/GaAs QD gain structure,which can generate ultrastable optical frequency combs in the O-band with 100 GHz spacing at operation temperature up to 100℃.A record-high flat-top optical comb is achieved with 3 dB optical bandwidth of 11.5 nm(20 comb lines)at 25℃.The average optical linewidth of comb lines is measured as 440 kHz.Single-channel non-return-to-zero modulation rates of 70 Gbit/s and four-level pulse amplitude modulation of 40 GBaud/s are also demonstrated.To further extend the comb bandwidth,an array of QD-CPMLs driven at separate temperatures is proposed to achieve 36 nm optical bandwidth(containing 60 comb lines with 100 GHz mode spacing),capable of a total transmission capacity of 4.8 Tbit/s.The demonstrated results show the feasibility of using the QD-CPML as a desirable broadband comb source to build future large-bandwidth and power-efficient optical interconnects.

Research on magnetic centermeasurement of quadrupole and sextupole using vibrating wire alignment technique in HEPS-TF

Purpose In order to meet the extremely low emittance requirement,the magnets in the storage ring of high-energy photon source(HEPS)need to have a stable support and precise positioning.In HEPS-TF,the key and difficult technologies of HEPS should be researched and developed.Vibrating wire alignment technique is one important project of HEPS-TF.It can be used to pre-align the quadrupoles and sextupoles on one girder with high precision.A vibrating wire measurement system was set up and tested to verify the magnetic center measurement precision and the magnet adjustment error.Methods There are one sextupole and one quadrupole installed on a multipole girder.Vibrating wire is stretched through mechanical center of the magnet apertures and supported by the test benches on the two sides.A single conducting wire is stretched through themagnet aperture and electrified by alternating current.The wire will vibrate for a period of Lorentz force.By matching the current frequency to one mode of natural frequency of the wire,the vibrating amplitude will be enhanced.And by measuring the vibrating amplitude,the magnetic field at the wire position can be got.Moving the wire across the magnet aperture in the transversal or vertical direction,the distribution of magnetic field and magnetic center position can be measured.According to the magnetic center position error to adjust the magnet.Measure the magnetic center of all magnets installed on the multipole girder one by one,and adjust their magnetic center to a line.Results The magnetic center measurement precision is better than±3μm,and the magnet adjustment error is less than 6μm.Conclusion The vibrating wire system design and a series of magnetic center measurement experiments have gained good achievements.It has been proved the vibrating wire system is designed reasonable and using the vibrating wire to align the magnets installed on a multipole girder is feasible and can reach a high precision.