bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypervascular Nodules and Stiffer Liver are Associated with Recurrence after Microwave Ablation in Patients with Hepatocellular Carcinoma: A Double-Center Analysis
Authors: Shehata Mona A. H. , El-Kady Nabeel , Hasaballah Maha , Mansour Loai , El-Gazzar Nabila , Abd-Elsalam Sherief
Published: March 2021

Background and Aims The aim of this study was to detect the most important risk factors for recurrence after microwave ablation (MWA) of hepatocellular carcinoma (HCC).

Methods A total of 92 patients with 110 HCC focal lesions (FLs) underwent MWA therapy. All the patients underwent triphasic CT before and after 1 and 3 months of MWA therapy. Complete ablation and recurrence rates were recorded, and the risk factors associated with recurrence were analyzed.

Results Regarding the 110 HCC FLs that were detected pre-MWA, adequate ablation was recorded post-MWA procedure in 88 FLs (80%) and incomplete ablation in 22 FLs (showed residual contrast enhancement). However, there were newly detected lesions (17 FLs). The rate of recurrence was significantly higher in patients with multiple larger (> 4 cm) sized and hypervascular nodules. Diabetics were significantly associated with a higher recurrence rate of HCC. The rate of recurrence was significantly higher in patients with baseline level of serum alfa-fetoprotein (AFP) ≥200 ng/mL. Stiffer liver> 25 kPa had higher incidence for recurrence after ablation.

Conclusion Meticulous follow-up is mandatory in diabetic patients, patients with AFP > 200 ng/dL starting value, hypervascular large hepatic FL, and in stiffer liver> 25 kPa, as these patients have higher incidence for recurrence after ablation.
Ocular Affection as an Extraintestinal Manifestation in Cases of Inflammatory Bowel Disease at the Kafrelsheikh Governorate
Authors: Ahmed Mohammed Hussien , Elashery Mohammed , Maksoud Hebatallah Abdel , Mahros Aya Mohammed
Published: March 2021

Introduction The manifestations of inflammatory bowel disease (IBD) are not restricted to the gastrointestinal tract. Musculoskeletal conditions are considered the most common extraintestinal manifestations, followed by mucocutaneous and ocular diseases. Many general practitioners are unaware of the variety and severity of the ocular affection in IBD patients.

Objective To assess the prevalence of extraintestinal manifestations in IBD patients at Kafrelsheikh governorate, and to evaluate the different ocular manifestations and their relationship to the severity of the disease.

Methods A cross-sectional study evaluating 120 patients treated at the Kafrelsheikh University Hospital. The diagnosis of IBD was made between December 2018 and December 2019 through clinical, endoscopic and histopathological examinations. All patients were assessed for any extraintestinal manifestation or evidence of ocular affection through slit-lamp examinations, tonometry, visual acuity, and indirect ophthalmoscopy.

Results The mean age of the sample was 35.5 ±  13.3 years. In total, 52 (43.3%) patients were male and 68 (56.7%) were female. Ocular manifestations represent ∼ 22.5% of extraintestinal manifestations. The most common ocular findings were conjunctivitis (25.8%) and anterior uveitis (10.8%), followed by scleritis (9.2%) and cataract (8.3%). Other extraintestinal manifestations were observed in 41 (34.1%) 29 (29.9%) of ulcerative colitis cases, and 12 (52%) of Crohn disease cases. There was no statistically significant difference in the presence of ocular involvement in relation to the two types of IBD included in the Montreal classification.

Conclusion Ocular manifestations in cases of IBD are common and usually nonspecific in presentation. The severity of the IBD does not reflect the severity of the ocular affection.
Safety of Transrectal or Transvaginal Drainage of Pelvic Abscesses
Authors: Mohammed Ilyas Mohammed Iyoob , Kandagatla Pridvi , Reickert Craig A. , Nalamati Surya , Webb Shawn P. , Szilagy Eric J. , Stefanou Amalia J.
Published: March 2021

Objective The literature on the safety and long-term sequelae of transrectal and transvaginal drainage of pelvic abscesses is limited. We evaluated the outcomes and safety of pelvic abscess drainage by interventional radiology at our institution.

Methods After obtaining institutional review board approval, we retrospectively evaluated the outcomes of transrectal and transvaginal pelvic abscesses drainage using computed tomography, endorectal ultrasound, and or fluoroscopy.

Results The study included 26 patients, with an age range of 24 to 88 years old, out of whom 53.8% were men. A total of 46.1% of the participants were African Americans and 26.9% were Caucasians. The average body mass index was 28.4 (range: 15.6 to 41.9). The most common etiology was penetrating abdominal injury (27%), followed by appendectomy (23%), diverticular disease (11.5%), anastomotic leak (11.5%), and disorders of gynecological causes (11.5%). The mean abscess diameter was 6.3 cm (range: 3.3 to 10.0 cm). Transrectal drainage was performed in all except one patient who had a transvaginal drainage. Transrectal ultrasound was used for drainage in 92.3% cases, and fluoroscopy was used as an additional imaging modality in 75% of the cases. An 8- or 10-Fr pigtail catheter was used in > 80% of the patients. Drains were removed between 2 and 7 days in 92.3% of the cases. The average follow-up was 30.4 months (range: 1 to 107 months), and no long-term complications were reported. Only one patient required subsequent operative intervention for an anastomotic leak.

Conclusions Pelvic abscess drainage by transrectal route using radiological guidance is a safe and effective procedure.
Short- and Long-Term Outcomes of Overlap Anal Sphincter Repair for Fecal Incontinence Following Sphincter Injury
Authors: Lakmal Kasun , Basnayake Oshan , Jayarajah Umesh , Samarasekera Dharmabandhu N
Published: March 2021

Objective Several techniques are used to repair the anal sphincter following injury. The aim of the present study is to comprehensively analyze the short- and long-term outcomes of overlap repair following anal sphincter injury.

Methods A search was conducted in the PubMed, Medline, Embase, Scopus and Google Scholar databases between January 2000 and January 2020. Studies that described the outcomes that are specific to overlap sphincter repair for fecal incontinence with a minimum follow-up period of one year were selected.

Results A total of 22 studies described the outcomes of overlap sphincter repair. However, 14 studies included other surgical techniques in addition to overlap repair, and were excluded from the analysis. Finally, data from 8 studies including 429 repairs were analyzed. All studies used at least one objective instrument; however, there was significant heterogeneity among them. Most patients were female (n = 407; 94.87%) and the mean age of the included individuals was 44.6 years. The majority of the procedures were performed due to obstetric injuries (n = 384; 89.51%). The eight included studies described long-term outcomes, and seven of them demonstrated statistically significant improvements regarding the continence; one study described poor outcomes in terms of overall continence. The long-term scores were significantly better compared with the preoperative scores. However, compared with the short-term scores, a statistically significant deterioration was noted in the long-term.

Conclusion The majority of the studies described good long-term outcomes in terms of anal continence after overlap sphincter repair. However, further studies are needed to identify the factors associated with poor outcomes to assist in patient selection for overlap repair.
Impact of Ambulatory Surgery for Hemorrhoidal Disease on Clinical Outcomes and Institutional Costs
Authors: Ascanelli Simona , Solari Stefano , Rubbini Michele , Aisoni Filippo , Forini Maria Elena , Carcoforo Paolo
Published: March 2021

Objective Transanal hemorrhoidal artery ligation with mucopexy (ligation anopexy [LA]) and open hemorrhoidectomy (OH) can both be performed under local anesthesia. The aim of the present study was to analyze the impact and the cost-effectiveness of performing these techniques in an ambulatory setting of an Italian academic center on the postoperative outcome.

Methods A series of 122 consecutive patients with grades II and III hemorrhoidal disease undergoing ambulatory surgical treatment of hemorrhoids in 2015 to 2018 (group A) was compared with 122 patients operated at the same institution in the same period (group H) in a hospital setting.

The primary outcome was the number of days required to return to work/daily activities. Secondary outcomes included postoperative pain and complications, cost-effectiveness, patient satisfaction, and recurrence at 12 months. In group A, all the procedures were performed under local anesthesia with early discharge. In group H, the procedures were performed under general or loco-regional anesthesia with hospital admission.

Results The mean number of days required to return to work/daily activities was 8.4 ± 4.8 days in group A, compared with 12.5 ± 3 days in group H (p < 0.001). The visual analog scale (VAS) pain score at 1 week, 2 and 3 weeks, and 1 month after surgery was lower for patients undergoing LA in the ambulatory setting (p < 0.01). We observed more postoperative complications in hospitalized (12.5%) than in ambulatory patients (7.5%) (p < 0.001). The total mean direct costs per patient were significantly lower in the ambulatory setting versus the hospital stay group (351.3 versus 1,746 euros).

Conclusion Implementing ambulatory surgery for hemorrhoids is feasible, safe, and cost-effective.
Various Uses of Laryngeal Mask Airway during Tracheal Surgery
Authors: Celik Ali , Sayan Muhammet , Kankoc Aykut , Tombul Ismail , Kurul Ismail Cüneyt , Tastepe Abdullah Irfan
Published: March 2021

Background The use of laryngeal mask airway (LMA) ventilation in surgeries to be performed in upper tracheal stenosis has been reported in the case series. However, there is no generally accepted standardized approach for the use of LMA. In this study, LMA usage areas and advantages of trachea surgery were examined.

Methods The records of 21 patients who underwent tracheal surgery using LMA ventilation between March 2016 and May 2020 were evaluated retrospectively. The patient data were analyzed according to age, gender, mean follow-up time, surgical indication, mean tracheal resection length, anastomosis duration, mean oxygen saturation, mean end-tidal CO2 levels, and postoperative complications.

Results Four patients were female and 17 were male, their median age was 43 (11–72 range) and the mean follow-up time was 17.6 months. The most common surgical indication was postintubation tracheal stenosis. The mean tracheal resection length was 26.6 mm and the mean anastomosis duration was 11.3 minutes. The mean pulse oximetry and mean end-tidal CO2 during laryngeal mask ventilation was 97.6% ± 2.1 and 38.1 ± 2.8 mm Hg, respectively. Postoperative complications were higher in patients with comorbidities.

Conclusion LMA-assisted tracheal surgery is a method that can be used safely as a standard technique in the surgery of benign and malignant diseases of both the upper and lower airway performed on pediatric patients, patients with tracheostomy, and suitable patients with tracheoesophageal fistula.
Computed Tomography Colonography as a Sensible Option for Colorectal Cancer Screening: Evidence Based on Metanalysis
Authors: Borges Ingrid Chaves de Souza , Cunha Natália Costa Resende , Rassi Amanda Marsiaj , de Oliveira Marcela Garcia , Leão-Cordeiro Jacqueline Andréia Bernardes , Ataides Fábio Silvestre , Almeida Rogério José , Vilanova-Costa Cesar Augusto Sam Tiago , Silva Antonio Márcio Teodoro Cordeiro
Published: March 2021

Objective This metanalysis aimed to evaluate the sensitivity and specificity of computed tomography colonography in colorectal polyp detection.

Methods A literature search was performed in the PubMed and Web of Science databases.

Results A total of 1,872 patients (males 57.2%, females 42.8%) aged 49 to 82 years old (mean age 59.7 ± 5.3 years) were included in this metanalysis. The estimated sensitivity of computed tomography colonography was 88.4% (46.3–95.7%, coefficient of variation [CV] = 28.5%) and the estimated specificity was 73.6% (47.4–100.0%, CV = 37.5%). For lesions up to 9 mm, the sensitivity was 82.5% (62.0–99.9%, CV = 25.1%) and the specificity was 79.2% (32.0–98.0%, CV = 22.9%). For lesions > 9 mm, the sensitivity was 90.2% (64.0–100.0%, CV = 7.4%) and the specificity was 94.7% (80.0–100.0%, CV = 6.2%). No statistically significant differences in sensitivity according to the size of the lesion were found (p = 0.0958); however, the specificity was higher for lesions > 9 mm (p < 0.0001).

Conclusions Most of the studies analyzed in the present work were conducted before 2010, which is about a decade after computed tomography colonography started being indicated as a screening method by European and American guidelines. Therefore, more studies aimed at analyzing the technique after further technological advancements are necessary, which could lead to the development of more modern devices.
Efficacy and Safety of Two Different Flow Rates of Nasal High-Flow Therapy in Preterm Neonates ≥28 Weeks of Gestation: A Randomized Controlled Trial
Authors: Balasubramanian Haribalakrishna , Sakharkar Sachin , Majarikar Swati , Srinivasan Lakshmi , Kabra Nandkishor S. , Garg Bhawandeep , Ahmed Javed
Published: March 2021

Objective The study aimed to compare the efficacy and safety of two different nasal high-flow rates for primary respiratory support in preterm neonates

Study Design In this single-center, double-blinded randomized controlled trial, preterm neonates ≥28 weeks of gestation with respiratory distress from birth were randomized to treatment with either increased nasal flow therapy (8–10 L/min) or standard nasal flow therapy (5–7 L/min). The primary outcome of nasal high-flow therapy failure was a composite outcome defined as the need for higher respiratory support (continuous positive airway pressure [CPAP] or mechanical ventilation) or surfactant therapy.

Results A total of 212 neonates were enrolled. Nasal high-flow failure rate in the increased flow group was similar to the standard flow group (22 vs. 29%, relative risk = 0.81 [95% confidence interval: 0.57–1.15]). However, nasal flow rate escalation was significantly more common in the standard flow group (64 vs. 43%, p = 0.004). None of the infants in the increased flow group developed air leak syndromes.

Conclusion Higher nasal flow rate (8–10 L/min) when compared with lower nasal flow rate of 5 to 7 L/min did not reduce the need for higher respiratory support (CPAP/mechanical ventilation) or surfactant therapy in moderately and late preterm neonates. However, initial flow rates of 5 L/min were not optimal for most preterm infants receiving primary nasal flow therapy.

Key Points
Presumptive Neonatal Multisystem Inflammatory Syndrome in Children Associated with Coronavirus Disease 2019
Authors: Divekar Abhay A. , Patamasucon Pisespong , Benjamin Joshua S.
Published: March 2021

Objective The study aimed to alert the neonatal community to the possibility of multisystem inflammatory syndrome in children (MIS-C) like disease in critically ill neonates born to mothers with coronavirus disease 2019 (COVID-19).

Study Design Diagnosis of MIS-C like disease was pursued after echocardiography showed severely depressed ventricular function and pathological coronary artery dilation in the setting of medically refractory multisystem organ failure and maternal COVID-19 infection. The neonate did not respond to standard medical therapy, and there was no alternative disease that could explain the clinical course. High index of clinical suspicion coupled with low risk of intravenous immunoglobulin (IVIG) prompted us to pursue IVIG administration even though the neonate did not meet classic criteria for MIS-C.

Result Following treatment with IVIG, there was rapid clinical improvement. Ventricular function improved within 15 hours and coronary artery dilation resolved in 8 days. There was no recurrence of disease during follow-up.

Conclusion COVID-19 associated MIS-C like disease has not been well described in neonates. As typical features may be conspicuously absent, a high index of suspicion is warranted in critically ill neonates born to mothers with COVID-19. Echocardiography may provide critical diagnostic information and narrow the differential diagnosis.

Key Points
Optimal field-effect transistor operation for high-resolution biochemical measurements
Authors: Le Son T. , Cho Seulki , Richter Curt A. , Balijepalli Arvind
Published: March 2021

Field-effect transistors (FETs) are powerful tools for sensitive measurements of numerous biomarkers (e.g., proteins, nucleic acids, and antigen) and gaseous species. Most research studies in this field focused on building discrete devices with high performance. We show that instrumentation that is commonly used in multiple areas of physics and engineering can greatly improve the performance of measurement systems that embed FET-based transducers for biological applications. We review the state-of-the-art instrumentation in the field as applied to sensing with FETs. We show how high-performance dual-gate 2D FETs that we recently developed, when operated using closed-loop proportional–integral–derivative control, can drastically improve both the sensitivity and resolution. We further show that this closed-loop control approach can be extended to commonly used single-gate silicon FETs. The generalizability of the results will allow their application to virtually any previously developed FET-based sensor. Finally, we provide insight into further optimization and performance benefits that can be extracted by using the closed-loop feedback approach for applications in biosensing.
Convergence to the fixed-node limit in deep variational Monte Carlo
Authors: Schätzle Z. , Hermann J. , Noé F.
Published: March 2021

Variational quantum Monte Carlo (QMC) is an ab initio method for solving the electronic Schrödinger equation that is exact in principle, but limited by the flexibility of the available Ansätze in practice. The recently introduced deep QMC approach, specifically two deep-neural-network Ansätze PauliNet and FermiNet, allows variational QMC to reach the accuracy of diffusion QMC, but little is understood about the convergence behavior of such Ansätze. Here, we analyze how deep variational QMC approaches the fixed-node limit with increasing network size. First, we demonstrate that a deep neural network can overcome the limitations of a small basis set and reach the mean-field (MF) complete-basis-set limit. Moving to electron correlation, we then perform an extensive hyperparameter scan of a deep Jastrow factor for LiH and H4 and find that variational energies at the fixed-node limit can be obtained with a sufficiently large network. Finally, we benchmark MF and many-body Ansätze on H2O, increasing the fraction of recovered fixed-node correlation energy of single-determinant Slater–Jastrow-type Ansätze by half an order of magnitude compared to previous variational QMC results, and demonstrate that a single-determinant Slater–Jastrow-backflow version of the Ansatz overcomes the fixed-node limitations. This analysis helps understand the superb accuracy of deep variational Ansätze in comparison to the traditional trial wavefunctions at the respective level of theory and will guide future improvements of the neural-network architectures in deep QMC.
A two-dimensional numerical model for the sliding motion of liquid drops by the particle finite element method
Authors: Mahrous Elaf , Roy R. Valéry , Jarauta Alex , Secanell Marc
Published: March 2021

Liquid drops sliding on surfaces are ubiquitous both in the natural and industrial world. The prediction of such drop motions has far-reaching implications in many fields of application, including microfluidics, phase change heat transfer, or coating technology. We present a numerical model based on the particle finite element method for the prediction of the sliding motion of liquid drops. The model includes the effect of a retention force which acts in the vicinity of the drop's contact line. This effect is found to be essential to obtain realistic spatiotemporal evolution of the drop. Thus far limited to two-dimensional simulations, the proposed model is validated by using experimental data found in the published literature, covering a wide range of drop size and physical properties. The numerical results are found to be mesh-independent and in good agreement with the experiments.
On the characteristics of N-polar GaN Schottky barrier contacts with LPCVD SiN interlayers
Authors: Khachariya Dolar , Szymanski Dennis , Breckenridge M. Hayden , Reddy Pramod , Kohn Erhard , Sitar Zlatko , Collazo Ramón , Pavlidis Spyridon
Published: March 2021

We study the behavior of N-polar GaN Schottky diodes with low-pressure chemical vapor deposited (LPCVD) SiN interlayers and unveil the important role of an amphoteric miniband formed in this interlayer due to a previously identified and dominating Si dangling bond defect. Through analysis of temperature-dependent current–voltage (I–V–T), capacitance–voltage (C–V), and x-ray photoelectron spectroscopy measurements, we observe that when nickel is deposited on LPCVD SiN pretreated with hydrofluoric acid, the SiN/GaN interface is responsible for determining the overall system's barrier height. By contrast, contact formation on oxidized LPCVD SiN leads to a metal/SiN-dominant barrier. We, consequently, propose band diagrams that account for an amphoteric miniband in LPCVD SiN, leading to a new understanding of LPCVD SiN as a lossy dielectric with surface barrier-dependent behavior.
Axisymmetric lattice Boltzmann formulation for mixed convection with anisotropic thermal diffusion and associated bubble breakdown
Authors: Gawas Amitkumar S. , Patil Dhiraj V.
Published: March 2021

The effect of the mixed convection with anisotropic thermal diffusion on the bubble breakdown inside a cylindrical cavity with a rotating top and the stationary bottom is investigated in this article. The lattice Boltzmann multiple relaxation time axisymmetric method with the D2Q9 model is used. The three distribution functions, one for axial and radial components of the velocity field, second for an azimuthal component of the velocity field, and third for the temperature field, are used. The code is validated for the fluid flow inside a lid-driven cylindrical cavity and for hot rotating-top-lid cylindrical cavity. The results are compared with the benchmark data. The effect of mixed convection on the Bödewadt boundary layer thickness and the temperature boundary layer thickness is investigated. The simulations are perfermed for various Reynolds number (Re) from of 990 and 2494, the Richardson number (Ri in 0.01 and 1, and Rayleigh number (Ra from 9801  and 6.22×106). This study concludes that the Bödewadt boundary layer thickness (δB) is ∝ to Ri and the temperature boundary layer thickness (δTc) is ∝ to Ri for 0.01≤ Ri ≤0.1. Further, the δB≈δTc for isotropic thermal diffusion. For an anisotropic thermal diffusion, the δB remains constant and δTc increases at Ri = 0.01 with an increase in the ratio of thermal diffusivity values (n). The bubble breakdown vanishes with an increase in Ri at a constant Re. The main application of this study is in the mixing/blending processes with convection inside cylindrical shaped reactors.
Developing “inverted-corona” fusion targets as high-fluence neutron sources
Authors: Hohenberger M. , Meezan N. B. , Riedel W. M. , Kabadi N. , Forrest C. J. , Aghaian L. , Cappelli M. A. , Farrell M. , Glenzer S. H. , Heeter B. , Heredia R. , Landen O. L. , Mackinnon A. J. , Petrasso R. , Shuldberg C. M. , Treffert F. , Hsing W. W.
Published: March 2021

We present experimental studies of inverted-corona targets as neutron sources at the OMEGA Laser Facility and the National Ignition Facility (NIF). Laser beams are directed onto the inner walls of a capsule via laser-entrance holes (LEHs), heating the target interior to fusion conditions. The fusion fuel is provided either as a wall liner, e.g., deuterated plastic (CD), or as a gas fill, e.g., D2 gas. Such targets are robust to low-mode drive asymmetries, allowing for single-sided laser drive. On OMEGA, 1.8-mm-diameter targets with either a 10-μm CD liner or up to 2 atm of D2-gas fill were driven with up to 18 kJ of laser energy in a 1-ns square pulse. Neutron yields of up to 1.5 × 1010 generally followed expected trends with fill pressure or laser energy, although the data imply some mix of the CH wall into the fusion fuel for either design. Comparable performance was observed with single-sided (1x LEH) or double-sided (2x LEH) drive. NIF experiments tested the platform at scaled up dimensions and energies, combining a 15-μm CD liner and a 3-atm D2-gas fill in a 4.5-mm diameter target, laser-driven with up to 330 kJ. Neutron yields up to 2.6 × 1012 were measured, exceeding the scaled yield expectation from the OMEGA data. The observed energy scaling on the NIF implies that the neutron production is gas dominated, suggesting a performance boost from using deuterium–tritium (DT) gas. We estimate that neutron yields exceeding 1014 should be readily achievable using a modest laser drive of ∼300 kJ with a DT fill.
An investigation of wake flows produced by asymmetrically structured porous coated cylinders
Authors: Arcondoulis Elias J. G. , Geyer Thomas F. , Liu Yu
Published: March 2021

The vortex shedding tone of a cylinder in uniform flow can be reduced by applying a porous coating yet this mechanism is not fully understood. An experimental investigation of asymmetric structured porous coated cylinders (SPCCs) was conducted in a small anechoic wind tunnel using a hot-wire anemometry probe placed in the boundary layer, separated shear layer and wake, in conjunction with a microphone in the far-field. Tests were conducted at Reynolds numbers 105, 1.53×105, and 1.66×105. Each SPCC revealed a widened and deeper wake and reduced turbulent kinetic energy levels in the separated shear layer than the bare baseline cylinder. Furthermore, each SPCC revealed two tones that were a multiple of two apart in both the velocity and acoustic power spectral densities. It was shown that the higher frequency tone is generated by localized flow behaviors in the separated shear layer, independent of the vortex shedding tone and its magnitude is inversely related to the SPCC windward surface porosity. Applying a more densely spaced porous region on the cylinder windward side resulted in higher frequency broadband contributions that were shown to be independent of the velocity fluctuations in the wake region. Time-averaged velocity profiles in the wake revealed that the leeward side porosity strongly influences the drag coefficient. Linear stability analysis revealed that the SPCCs develop absolute instabilities in the near wake.
TSV-integrated surface electrode ion trap for scalable quantum information processing
Authors: Zhao P. , Likforman J. P. , Li H. Y. , Tao J. , Henner T. , Lim Y. D. , Seit W. W. , Tan C. S. , Guidoni L.
Published: March 2021

In this study, we report about the design, fabrication, and operation of a Cu-filled through-silicon via (TSV)-integrated ion trap. TSVs are placed directly underneath electrodes as vertical interconnections between an ion trap and a glass interposer, facilitating the arbitrary geometry design with increasing electrode numbers and evolving complexity. The integration of TSVs reduces the form factor of the ion trap by more than 80%, minimizing parasitic capacitance from 32 ± 2 to 3 ± 0.2 pF. A low RF dissipation is achieved in spite of the absence of the ground screening layer. The entire fabrication process is on a 12-in. wafer and compatible with the established CMOS back end process. We demonstrate the basic functionality of the trap by loading and laser-cooling single 88Sr+ ions. It is found that both the heating rate (17 quanta/ms for an axial frequency of 300 kHz) and lifetime (∼30 min) are comparable with traps of similar dimensions. This work pioneers the development of TSV-integrated ion traps, enriching the toolbox for scalable quantum computing.
Numerical investigation on vortex-induced vibration suppression of the cactus-inspired cylinder with some ribs
Authors: Wang Wei , Mao Zhaoyong , Song Baowei , Han Peng
Published: March 2021

Vortex-induced vibration (VIV) responses of the cactus-inspired cylinder with some ribs are numerically investigated, and the range of Reynolds number is 8.0 × 103 < Re < 5.6 × 104. The motion equations of VIV response are solved by the Newmark-beta method. The effects of different numbers of ribs (N, N is the number of the ribs) on VIV suppression are investigated in detailed, and six different numbers of ribs (N) include S0 (N = 0), S1 (N = 8), S2 (N = 12), S3 (N = 16), S4 (N = 20) and S5 (N = 24). The peak value of the cross-flow amplitude ratio decreases from 1.50 (S0) to 0.65 (S2), which is reduced by about 56.67%. The peak value of the in-line amplitude ratio decreases from 0.35 (S0) to 0.12 (S2, S3, S4, and S5), which is reduced by about 65.71%. The peak value of the mean drag coefficient decreases from 3.00 (S0) to 2.1 (S2), reduced by about 30.0%. When N = 8, VIV response is enhanced and it can contribute to trigger the large-amplitude or even divergent structural motion, such as galloping. When N ≥ 12, the VIV responses of S2, S3, S4, and S5 are all suppressed. When N ≥ 12, the range of the lock-in region is wider and wider as the number of ribs increase, and the range of lock-in region of S5 (N = 24) is the similar to that of S0 (N = 0). For the cactus-inspired cylinder, the detached boundary-layer is usually formed between two ribs and the smaller vortices are formed between the ribs. And the ribs of the cactus-inspired cylinder destroy the normal boundary-layer separation and reduce the strength of the wake vortex for S2, S3, S4 and S5. However, the reattachment of the boundary layer occurs after the first separation of the boundary layer for S1, which may cause unstable VIV response. Especially, galloping phenomenon may occur in the high Reynolds number for S1. Compared with the separation line of the smooth cylinder (S0), the separation line of the cactus cylinder (S5) obviously develops away from the cylinder and the coupling process of the wake vortex is suppressed.
Ferroic properties and piezoelectric response of Mg2XN3 (X = V, Cr)
Authors: Hu Minglang , Yang Xiaoqing , Su Tianhao , Ma Xiaonan , Ren Wei
Published: March 2021

Nitrides are of increasing interest since they are usually wide-bandgap semiconductors and the available environmental raw materials are abundant. Using first-principles predictions, we reveal that Mg2XN3 (X = V, Cr) compounds show remarkably large ferroelectric polarization and piezoelectric response. Quantitative theoretical analysis further indicates the asymmetric orbital hybridization to be the origin of the ferroelectricity. Since Cr has one more 3d electron than V, it is found that Mg2CrN3 is multiferroic with a ferromagnetic ground state. We further show that the epitaxial strain can regulate the piezoelectricity, and thus, both Mg2CrN3 and Mg2VN3 exhibit a larger piezoelectric response than the reported nitride piezoelectric materials under appropriate tensile epitaxial strain. Our findings provide guidance for potential applications of nitride materials in spintronics, sensors, and memory devices.
Genetic analyses reveal cryptic diversity in the widely distributed
Authors: Corrêa de Barros Rodolfo , Moreira da Rocha Rosana
Published: March 2021

The routine use of DNA sequencing techniques and phylogenetic analysis has resulted in the discovery of many cryptic species, especially in the oceans. The common, globally introduced species Styela canopus is suspected to be a complex of cryptic species because of its widespread distribution and variable external morphology. We tested this possibility using COI and ANT marker sequences to uncover the phylogenetic relationship among 19 populations, and to examine genetic variability as well as gene flow. We obtained 271 COI and 67 ANT sequences and found surprising diversity among the 19 populations (COI: π = 0.18, hd = 0.99; ANT: π = 0.13, hd = 0.95). Corresponding topologies were found using Bayesian inference and maximum likelihood for both simple locus (COI) and multilocus (COI + ANT) analyses and so the clades received strong support. We used simple (ABGD, bPTP, GMYC) and multiple (BSD) locus methods to delimit species. The simple locus methods indicated that the current Styela canopus comprises at least 15 species. The BSD method for concatenated data supported 7 of the 15 species. We suggest that S. canopus should be treated as the Styela canopus complex. The large number of cryptic species found, often with more than one clade found in sympatry, creates opportunities for better understanding reproductive isolation, hybridisation or speciation. As several lineages have already been introduced widely around the world, we must quickly understand their diversity and invasive abilities.
Impacts of mechanical and chemical factors on the water-holding capacity of polyacrylamide in sand: models and mechanisms
Authors: Wu Yudi , Li Simeng , Chen Gang
Published: March 2021

Owing to its significant capacity to conserve water in soils, polyacrylamide (PAM) hydrogels have been applied extensively in croplands to combat droughts. However, the influences of different mechanical and chemical factors of sand on its swelling capacity is still unclear. The objective of this study is to reveal the relationships between swelling profile of PAM in sand and sand mechanical and chemical properties, using an originally designed laboratory-scaled column apparatus. Different water management strategies and sand properties, including water infiltration rates (0.6, 1.4, 1.9, and 2.5 m day–1), application depth (5.5, 11.0, and 16.5 cm), solution pH (5.0, 6.9 and 9.0), and ionic strengths (0.001, 0.01, and 0.1 M) were investigated in the present study. Chemical properties of sand medium (i.e. ionic strengths and pH conditions) reduced up to 70% of water holding capacity. Vertical stress limited water holding capacity to 50–60% of the maximum value, demonstrating that its effect has been underestimated in the past. Infiltration rate influenced the swelling profile but not the maximum water holding capacity. Results were fitted with the Korsmeyer-Peppas model, Gallagher-Corrigan model and First-Order model to derive parameters that highlight the impacts of the sand properties. Through model simulation, swelling behaviour was well explained with rapid swelling followed by further release in swelling. The discoveries in this study demonstrate the important roles of mechanical and chemical factors during the water absorption process of agricultural hydrogels.
The politics of identity in diasporic media1
Authors: Patiño-Santos Adriana
Published: March 2021

By following a sociolinguistic, ethnographic approach, this paper explores the intricacies behind the construction of a collective identity in the practices of a community radio station, off- and on-air, that serves the Spanish speaking Latin American community in London. The analysis of the information gathered from a 6-months ethnography conducted in a well-established radio station in South London, allowed me to document how the politics of identity delivered on air, far from being a straightforward process, entails some decisions regarding what to say and how, in order to deliver harmonious relations. The shared use of the Spanish language, albeit in different varieties, and some perceived shared values, become the salient markers to present this harmonious identity. Projecting a unified group identity is seen as an important aim for migrants when navigating diaspora in the UK.
Recordings from neuron–HEK cell cocultures reveal the determinants of miniature excitatory postsynaptic currents
Authors: Chiang Chung-Wei , Shu Wen-Chi , Wan Jun , Weaver Beth A. , Jackson Meyer B.
Published: March 2021

Spontaneous exocytosis of single synaptic vesicles generates miniature synaptic currents, which provide a window into the dynamic control of synaptic transmission. To resolve the impact of different factors on the dynamics and variability of synaptic transmission, we recorded miniature excitatory postsynaptic currents (mEPSCs) from cocultures of mouse hippocampal neurons with HEK cells expressing the postsynaptic proteins GluA2, neuroligin 1, PSD-95, and stargazin. Synapses between neurons and these heterologous cells have a molecularly defined postsynaptic apparatus, while the compact morphology of HEK cells eliminates the distorting effect of dendritic filtering. HEK cells in coculture produced mEPSCs with a higher frequency, larger amplitude, and more rapid rise and decay than neurons from the same culture. However, mEPSC area indicated that nerve terminals in synapses with both neurons and HEK cells release similar populations of vesicles. Modulation by the glutamate receptor ligand aniracetam revealed receptor contributions to mEPSC shape. Dendritic cable effects account for the slower mEPSC rise in neurons, whereas the slower decay also depends on other factors. Lastly, expression of synaptobrevin transmembrane domain mutants in neurons slowed the rise of HEK cell mEPSCs, thus revealing the impact of synaptic fusion pores. In summary, we show that cocultures of neurons with heterologous cells provide a geometrically simplified and molecularly defined system to investigate the time course of synaptic transmission and to resolve the contribution of vesicles, fusion pores, dendrites, and receptors to this process.
Evolution of ion-irradiated point defect concentration by cluster dynamics simulation*
Authors: Feng Shuaishuai , Lv Shasha , Chen Liang , Li Zhengcao
Published: March 2021

The relationship between ions irradiation and the induced microstructures (point defects, dislocations, clusters, etc.) could be better analyzed and explained by simulation. The mean field rate theory and cluster dynamics are used to simulate the effect of implanted Fe on the point defects concentration quantitatively. It is found that the depth distribution of point defect concentration is relatively gentle than that of damage calculated by SRIM software. Specifically, the damage rate and point defect concentration increase by 1.5 times and 0.6 times from depth of 120 nm to 825 nm, respectively. With the consideration of implanted Fe ions, which effectively act as interstitial atoms at the depth of high ion implantation rate, the vacancy concentration C
v decreases significantly after reaching the peak value, while the interstitial atom concentration C
i increases significantly after decline of the previous stage. At the peak depth of ion implantation, C
v dropped by 86%, and C
i increased by 6.2 times. Therefore, the implanted ions should be considered into the point defects concentration under high dose of heavy ion irradiation, which may help predict the concentration distribution of defect clusters, further analyzing the evolution behavior of solute precipitation.
Modeling of cascaded high isolation bidirectional amplification in long-distance fiber-optic time and frequency synchronization system*
Authors: Mu Kuan-Lin , Chen Xing , Wang Zheng-Kang , Qiao Yao-Jun , Yu Song
Published: March 2021

We propose a physical model of estimating noise and asymmetry brought by high isolation Bi-directional erbium-doped fiber amplifiers (Bi-EDFAs), no spontaneous lasing even with high gain, in longdistance fiber-optic time and frequency (T/F) synchronization system. It is found that the Rayleigh scattering noise can be suppressed due to the high isolation design, but the amplified spontaneous emission (ASE) noise generated by the high isolation Bi-EDFA and the bidirectional asymmetry of the transmission link caused by the high isolation Bi-EDFA will deteriorate the stability of the system. The calculated results show that under the influence of ASE noise, the frequency instability of a 1200 km system composed of 15 high isolation Bi-EDFAs is 1.773 × 10−13/1 s. And the instability caused by asymmetry is 2.6064 × 10−16/30000–35000 s if the total asymmetric length of the bidirectional link length is 30 m. The intensity noises originating from the laser and detector, the transfer delay fluctuations caused by the variation in ambient temperature and the jitter in laser output wavelength are also studied. The experiment composed of three high isolation Bi-EDFAs is done to confirm the theoretical analysis. In summary, the paper shows that the short-term instability of the T/F synchronization system composed of high isolation Bi-EDFAs is limited by the accumulation of ASE noise of amplifiers and the laser frequency drift, while the long-term instability is limited by the periodic variation in ambient temperature and the asymmetry of the amplifiers. The research results are useful for pointing out the direction to improve the stability of the fiber-optic T/F synchronization system.
Hydrodynamics of a superfluid smectic
Authors: Hofmann Johannes , Zwerger Wilhelm
Published: March 2021

We determine the hydrodynamic modes of the superfluid analog of a smectic-A liquid crystal phase, i.e., a state in which both gauge invariance and translational invariance along a single direction are spontaneously broken. Such a superfluid smectic provides an idealized description of the incommensurate supersolid state realized in Bose–Einstein condensates with strong dipolar interactions as well as of the stripe phase in Bose gases with spin–orbit coupling. We show that the presence of a finite normal fluid density in the ground state of these systems gives rise to a well-defined second-sound type mode even at zero temperature. It replaces the diffusive permeation mode of a normal smectic phase and is directly connected with the classic description of supersolids by Andreev and Lifshitz in terms of a propagating defect mode. An analytic expression is derived for the two sound velocities that appear in the longitudinal excitation spectrum. It only depends on the low-energy parameters associated with the two independent broken symmetries, which are the effective layer compression modulus and the superfluid fraction.
Analysis of transient processes in levitation electromechanical systems including effects of magnetic potential hole
Authors: Czaban A , Łukasik Z , Lis M , Szafraniec A
Published: March 2021

A mathematical model of a dynamic system including superconducting electric circuits and effects of the magnetic potential hole is presented. Motion transmission of the magnetic cushion rapid train, known as maglev train, which uses natural magnetic static levitation, is modelled on this basis. Starting from the model, transient electromechanical processes in an integrated dynamic system are analysed. The model is presented as a system of non-linear differential equations in the normal Cauchy’s form. The equations are integrated by means of explicit numerical methods. Results of computer simulations are illustrated as graphs whose behaviour is analysed.
Evaluation of plant spatial placement by TF POLYM Software
Authors: Findura P , Bartoš P , Prístavka M , Urbanovičoà O , Miernik A , Kiełbasa P
Published: March 2021

Food production intensity is a key issue in the modern world. Due to the development of the possibility of increasing the production area, the technology is constantly being improved and supplemented to increase their efficiency. The basis of any cultivation is sowing, which should provide everyone with a suitable living space. It allows the plant to effectively use the applied fertilization, chemical protection or mechanical treatments. The article develops the options for determining the living space of plants. The computational algorithm uses the Voronoi diagram belonging to the computational geometry technique, and then the Delphi software, the TfPolyM computer application, which was developed at the Faculty of Engineering of the Slovak University of Agriculture in Nitra. Based on the digitization of photos, the software is able to calculate the living space of the plant, and also allows for a precise assessment of the uniformity and quality of planting.
Hardening of steel axially symmetrical elements heated with two-turn inductor
Authors: Iskierka S , Iskierka I
Published: March 2021

This research the complex model of induction hardening of tool steel was shown. Electomagnetic phenomena, thermal phenomena and phase transformations were taken into considerations. The electromagnetic and the heat transfer equations have been solved by finite elements method by Galerkin formulations. Model of estimation of phase fractions and their kinetics has been based on the isothermal transformation diagram (TTT). Phase fractions which occur during the continuous heating and cooling (austenite, pearlite or bainite) are described by Johnson-Mehl-Avrami formula. To determine of the formed martensite the modified Koistinen-Marburger equation is used.
The use of microwave radiation with a frequency of 2.45 GHz as a factor reducing the storage losses of potato tubers
Authors: Jakubowski T , Syrotyuk S , Yankovska K
Published: March 2021

The goal of the paper is to evaluate the suitability of the 2.45 GHz microwave radiation in reducing the potato tubers storage losses. The experiment was conducted for three consecutive storage seasons on six edible potato varieties. It was determined that reaction of potato tubers to microwave radiation defined by processes taking place during the storage has a varietal character. Some microwave-irradiated combinations showed tendencies for increased germination. One potato variety responded to microwave radiation with significantly lower degree of infection by black scurf.
Influence of the constant electric field on the photon emission characteristics of selected utility cultivars of the Camellia plant
Authors: Miernik A , Kiełbasa P , Findura P , Byrska K
Published: March 2021

The article presents the research results related to the measurement of the reaction biological substance to extortion, which was a permanent field electric. To identify the degree of reaction of a biological substance, the phenomenon of generating short light pulses was used, which was registered with a photomultiplier tube turned on in appropriate measurement path. For the research, dried leaves of the Camellia plant were used, which was subjected to the influence of a constant electric field in two voltage combinations, i.e. 1kV and 3kV, and then, using the method of counting single photons, their number was summed in a 1800-second time interval. Significant differences in the number of registered photons were found between the drought subjected to the action of a constant electric field and the drought, where this interaction was not applied. It should be noted that a differentiation was also noted between the dried plants that were subjected to a constant electric field, but with different voltage. Therefore, it is possible, experimentally confirmed, to parameterize the analyzed substance by measuring the total photon emission and identifying selected properties of the substance based on the photon emission characteristics during the measurement..