Small Diameter Research Articles

Rotation periods of asteroids from light curves of TESS data

Understanding the dynamical evolution of asteroids through the secular Yarkovsky effect requires the determination of many physical properties, including the rotation period. We propose a method aimed at obtaining a robust determination of the rotation period of asteroids, while avoiding the pitfalls of aliases. We applied this approach to thousands of asteroid light curves measured by the NASA mission. We developed a robust period-analysis algorithm based on a Fourier series. Our approach includes a comparison of the results from multiple orders and tests on the number of extremes to identify and reject potential aliases. We also provide the uncertainty interval for the result as well as additional periods that may be plausible. We report the rotation period for nbTenPercent asteroids within a precision of 10<!PCT!>. A comparison with the literature (whenever available) reveals a very good agreement and validates the approach presented here. Our approach also highlights cases for which the determination of the period should be considered invalid. The dataset presented here confirms the apparent small number of asteroids with a rotation between 50 and 100 h and correlated with diameter. The amplitude of the light curves is found to increase toward smaller diameters, as asteroids become less and less spherical. Finally, there is a systematic difference between the broad C and S complex in the amplitude-period, revealing the statistically lower density of C-types compared to S-type asteroids. Our approach to the determination of asteroid rotation period is based on simple concepts, yet it is nonetheless robust. It can be applied to large corpora of time series photometry, such as those extracted from exoplanet transit surveys.

Complications associated with loop ileostomy: analysis of risk factors.

Loop ileostomy is a common surgical procedure but is associated with complications such as outlet obstruction (OO), parastomal hernia (PH), and high-output stoma (HOS). This study aimed to identify risk factors for these complications, as well as their causal relationships. The study included 188 consecutive patients who underwent loop ileostomy between April 2016 and September 2021. Clinical factors and postoperative stoma-related complications (OO, HOS, and PH) were analyzed retrospectively. Stoma-related factors were evaluated using specific measurements from computed tomography (CT) scans. The incidence, clinical course, and risk factors for the stoma-related complications were investigated. OO was diagnosed in 28 cases (15.7%), PH in 60 (32%), and HOS in 57 (31.8%). A small longitudinal stoma diameter at the rectus abdominis level on CT and a right-sided stoma were significantly associated with OO. Creation of an ileostomy for anastomotic leakage was independently associated with HOS. Higher body weight and a large longitudinal stoma diameter at the rectus abdominis level on CT were significantly associated with PH. There was a significant relationship between the occurrence of OO and HOS. However, the association between OO and PH was marginal. This study identified key risk factors for OO, HOS, and PH as complications of loop ileostomy and their causal relationships. Our findings provide insights that may guide the prevention and management of complications related to loop ileostomy.

Numerical investigation of CH4/H2/air micro-mixing combustion flow in a micro gas turbine combustor with different head-end structures

In order to investigate the premixed combustion characteristics of CH4/H2/air in a micro-mixing combustor, the effects of different micro-mixing head-ends (HE1, HE2, HE3) and hydrogen mixing ratios on the temperature distribution, heat transfer process, emission characteristic, flames shape are analyzed. The results show that compared with swirl head-end combustion, the micro-mixing combustion performance is better. Among the three head-ends, HE3 has the best combustion characteristics and stable flames. The temperature distribution in the high-temperature zone is uniform, and low-temperature zone is concentrated near the jet, which can suppress the flashback. The velocity and temperature gradient near the central axis of jet streams show a strong synergistic effect. The flames are plume shaped and flames stability is mainly influenced by the H2 combustion process. Increasing the jet diameter, decreasing the jet spacing and increasing the hydrogen mixing ratio all contribute to the flames stability, but these three methods can stabilize the flames by affecting fluid Reynolds number, interaction between small flames and combustion rate, respectively. Moreover, small jet diameter and high hydrogen mixing ratio can reduce OTDF, which contributes to improve outlet temperature uniformity.

Saccular and Fusiform Abdominal Aortic Aneurysms Treated With Endovascular Repair Differ in Presentation and Treatment Threshold: Analyses Using a National Clinical Database in Japan.

Saccular abdominal aortic aneurysms (AAAs) are considered to be at higher risk of rupture than fusiform AAAs, but not much is known about the extent of this risk. Therefore, this study aimed to compare the rupture presentation between fusiform and saccular AAAs. This is a retrospective cohort study on 27 290 patients who underwent primary endovascular repair for a degenerative AAA between 2016 and 2019, and who were registered in the National Clinical Database in Japan. At operation for nonruptured case, the aneurysm diameter was significantly smaller in saccular AAAs than in fusiform AAAs (median, 44.0 versus 51.0 mm; P<0.001). Similarly, aneurysm diameter at rupture was significantly smaller in saccular AAAs than in fusiform AAAs (median, 55.6 versus 68.0 mm; P<0.001). The likelihood of repair for rupture was significantly higher in saccular AAAs than in fusiform AAAs in the 40- to 54-mm diameter range, in which saccular morphology was found to be an independent risk factor for rupture against fusiform morphology by adjusting for sex and aneurysm diameter (odds ratio, 2.54 [95% CI, 1.75-3.69]). In addition, receiver-operating characteristic curve analysis revealed that the cutoff diameter to predict rupture was smaller in saccular AAAs than in fusiform AAAs (50.5 and 59.5 mm, respectively) based on the Youden index. Saccular AAAs presented at smaller diameters than fusiform AAAs in patients with ruptured AAAs treated with endovascular aortic repair, which supports the idea that saccular AAAs should be treated at smaller diameters.

Component Effects in Binary Droplet Impact Behaviors on the Heated Plate: Comparison Study of Ethanol/Propanol and Ethanol/Water Droplets and Observation of Novel Bubble Shrinkage Phenomenon

This work aims to investigate the effect of liquid physical properties on the behavior of binary droplets impact on the heated smooth aluminum alloy plate with a high-speed imaging system. Two groups of mixed solutions with similar boiling point differences are selected as the working liquid, in which the low-boiling-point components are both ethanol and the high-boiling point components are propanol and water, respectively. Compared to the ethanol/propanol binary droplets, the experimental results show that the ethanol/water binary droplets have diverse impact phenomena and significantly broad transition boiling regimes, as well as the reduced droplet residence time and increased Leidenfrost temperature point. With the decreasing ethanol content in ethanol/water binary droplets, these effects become more prominent. For secondary atomization, the ethanol/water binary droplet undergoes parent droplet breakup into fragment droplets with larger diameters (Ds &gt; 0.3 mm). Both binary droplets produce satellite droplets with small diameters (Ds &lt; 0.3 mm) by puffing and ejection. In terms of the ethanol/propanol binary droplet impact, the probability of puffing is higher and the satellite droplet diameters are small. In the ethanol/water binary droplet impact, the probability of ejection is higher and the satellite droplet diameter distribution is wider. When an ethanol/water binary droplet of 25 vol.% ethanol content impacts the heated wall at Ts = 120 °C, a novel large bubble shrinkage phenomenon occurs at the late stage of droplet evaporation. This phenomenon is proposed to be relevant to the increasing surface tension and saturation temperature with decreasing ethanol content, as well as the decreasing ambient temperature above the top surface of the bubble.

The Challenge of E-Spinning Sub-Millimeter Tubular Scaffolds—A Design-of-Experiments Study for Fiber Yield Improvement

In tissue engineering, electrospinning has gained significant interest due to its highly porous structure with an excellent surface area to volume ratio and fiber diameters that can mimic the structure of the extracellular matrix. Bioactive substances such as growth factors and drugs are easily integrated. In many applications, there is an important need for small tubular structures (I.D. &lt; 1 mm). However, fabricating sub-millimeter structures is challenging as it reduces the collector area and increases the disturbing factors, leading to significant fiber loss. This study aims to establish a reliable and reproducible electrospinning process for sub-millimeter tubular structures with minimized material loss. Influencing factors were analyzed, and disturbance factors were removed before optimizing control variables through the design-of-experiments method. Structural and morphological characterization was performed, including the yield, thickness, and fiber arrangement of the scaffold. We evaluated the electrospinning process to enhance the manufacturing efficiency and reduce material loss. The results indicated that adjusting the voltage settings and polarity significantly increased the fiber yield from 8% to 94%. Variations in the process parameters also affected the scaffold thickness and homogeneity. The results demonstrate the complex relationship between the process parameters and provide valuable insights for optimizing electrospinning, particularly for the cost-effective and reproducible production of small tubular diameters.

Optimization and modeling of solar photocatalytic degradation of raw textile wastewater dyes using green ZnO-ED NPs by RSM

ABSTRACT This study aims to use green ZnO-ED NPs produced from Eleocharis dulcis (E. dulcis) extract to maximize solar photocatalytic degradation of raw textile wastewater. The optimization of photocatalysis was decided using the response surface methodology (RSM) as a function of ZnO-ED NPs mass load (0.1–2 g), initial concentration (10–100%), pH (4–9), and contact time (60–200 min). The maximum decolorization (87.34%) and COD removal (100%) were recorded at pH 7, time (60 min), ZnO-ED NPs dosage (2 g/L), and 10% of color concentrations with R2 coefficient of 0.78 at p &amp;lt; 0.05. FESEM analysis showed the presence of granules with smaller diameters than the diameter of the ZnO-ED NPs granules before SPD. EDX analysis revealed the presence of impurities like copper (Cu). XRD analysis indicated the purity of ZnO-ED NPs after SPD, as the values were all quite similar to the XRD values before SPD. The results of an AFM analysis presented that agglomerations of ZnO-ED NPs, in contrast, were somewhat homogeneous in size, nature, and dispersion before SPD.

Design and development of a novel multirotor configuration with counter-rotating coaxial propellers

In this study, a novel multirotor configuration has been developed, which utilizes a coaxial counter-rotating propeller with a large diameter at the center and four propellers with smaller diameters on four arms in an X configuration. The research pursues two main objectives. The first objective is to establish a development method for multirotors based on the well-known V-method approach in system development. The proposed method enables the design team to analyse and evaluate the multirotor at each stage of the design process, from the system to the component level, and improve the design with greater speed and accuracy. Additionally, the proposed approach can be integrated with various optimization methods, if necessary, to achieve an optimal design. The second objective is to provide the proof-of-concept of the novel multirotor configuration. This objective is pursued across different evaluation sections, from evaluating individual components to fully evaluating the multirotor, to assess the performance of this novel configuration and identify its advantages and disadvantages. The results of various evaluations demonstrate the proposed development process's practicality and proves that the novel configuration is operational and competitive with conventional multirotors in various applications.

Relationship Between Diameter and Pelvic Vein Reflux

Introduction: Diameter has been a complementary measurement in the evaluation of venous valvular insufficiency of superficial veins of the lower extremity. Small veins with reflux or large veins without reflux may indicate alternative treatments. Awareness of pelvic vein reflux is increasing. The pelvic vein diameter-reflux relationship was investigated. Methods: Findings of lower extremity ultrasound (US) and/or clinical conditions—pelvic pain, dyspareunia and dysmenorrhoea—were indications for pelvic/abdominal venous US. Complete US examination included renal, internal iliac and gonadal/ovarian veins. Diameters of the largest right or left pelvic veins were compared with presence of reflux. Intravaginal US was completed in 104 women, age 46 ± 11 (standard deviation) (range 25-76) years old. Pelvic symptoms were reported by 30 (29%) patients. The other patients had pelvic-related recurrent varicose veins or suspected pelvic source of lower extremity venous reflux. Positive and negative predictive values (PPV, NPV) and other statistics at the 90-95% level were calculated relating diameter to pelvic vein reflux. Results: Pelvic vein reflux was detected in 54 (52%) women. Pelvic vein diameters were larger in refluxing, 8.4 ± 1.9 (5.1-14.0) mm, than in nonrefluxing veins, 5.2 ± 1.0 (3.4-8.3) mm ( P &lt; .001 by t test). Diameters ≥6.3 mm had 91% (49/54) sensitivity and 92% (49/53) PPV. Diameters ≤6.3 mm had 94% specificity (47/50) and 89% (47/53) NPV. All veins with diameter ≥8.4 mm ( n = 21) had reflux. All veins with diameter ≤5.0 mm ( n = 27) did not have reflux. Conclusions: Probabilities of pelvic vein reflux were estimated based on diameters. Diameter-reflux agreement solidifies diagnosis. An explanation for contradiction between small diameter and reflux or large diameter and no reflux is recommended.

Super (Edge-)connectivity of the Folded Petersen Network

Reliability evaluation of an interconnection network is of great significance for construction and maintenance of the network. The super (edge-)connectivity, restricted (edge-)connectivity and cyclic (edge-)connectivity are important parameters to evaluate network reliability. Compared with the hypercube [Formula: see text], the folded Petersen network [Formula: see text] has better properties, including strong connectivity, symmetry. Besides, it has smaller diameter and more vertices than [Formula: see text] with the same degree and connectivity. In this paper, based on the symmetric properties of [Formula: see text], we prove that [Formula: see text] is super (edge-)connected, super restricted edge-connected and super cyclically edge-connected. In addition, we obtain the restricted edge-connectivity and the cyclic edge-connectivity of [Formula: see text].

Investigation of soliton solutions for the NWHS model with temperature distribution in an infinitely long and thin rod

This study proposed a modified [Formula: see text]-expansion method to seek the new exact traveling wave solutions of the Newell–White–Head–Segel (NWHS) Model. This is an amplitude equation utilized for distributing temperature within a rod that is infinitely thin and long, or determining the flow velocity of a fluid through a pipe that is infinitely long but has a small diameter. The modified [Formula: see text]-expansion method is used to extract the new exact solutions. The solutions of this model are categorized in hyperbolic, trigonometric, and rational forms. Moreover, we compare our results with the new auxiliary equation method. The 3D, line and corresponding contour representation of these solutions are depicted by choosing the different values of parameters.

Calculation of Column Pile Heave in Deep Excavation Based on the Rebound–Recompression Method

Excessive column pile heave may result in engineering disasters such as instability of retaining structures and cracking of existing engineering piles in deep excavations. However, factors such as support weight, changeable support restraint resistance, and soil disturbance at the bottom of the excavation are often ignored or simplified in existing calculation methods but have a significant impact on the calculation results. Based on field soil parameters obtained by the rebound–recompression method, a semi-analytical method is proposed for estimating column pile heaves in a deep excavation. This method considers the influence of soil disturbance, the weight of the retaining structure, and the changeable horizontal support restraint, making the calculation result more consistent with the realistic situation. This method can also be used to analyze load transfer between the pile and the surrounding soil. The rationality of this proposed calculation method is verified by measured data, where the variation in pile stress state during deep excavation is analyzed. Finally, a parametric study is conducted, and the results show that the excavation size and the excavation depth have a great influence. However, the heave is hardly affected by the value of the limit relative displacement. The use of long piles with small diameter and the method of small block excavation are effective means to control the column pile heave. When the excavation area is large or the effective pile length is short, the factor of the position of the column pile cannot be ignored.

Manure temperature prediction for slurry storage in Sweden: Model validation including effects of shading, snow cover and mixing

Measuring and modelling manure temperatures are crucial for estimating greenhouse gas emissions from liquid manure storage. The manure temperature was recorded at various depths in two swine slurry storage tanks situated in Vallentuna (VA) and Örsundsbro (OR) in Sweden. These data were used to assess the effectiveness of a revised mechanistic model for estimating manure temperatures, which incorporates the effects of wall shading, snow cover, and manure input mixing. The average manure temperatures were higher than air temperatures in the summer and fall. This indicated that using air temperature would result in an underestimation of methane emissions when applying the 2019 IPCC Refinement methodology. The revised model estimated manure temperatures for spring, summer, fall, and winter as 4.8, 16.1, 7.8, and 2.6 °C at the VA tank and 11.6, 17.1, 9.5, and 3.6 °C at the OR tank. The root mean square errors between daily simulated and observed temperatures in the summer decreased in both tanks due to incorporating shadow effect into the revised model. Fall estimates did not improve, possibly because of uncertainties from slurry removal and higher precipitation inputs. Sensitivity analysis indicated that solar radiative heat input was reduced with higher tank walls and smaller tank diameters when applying the revised model. Wall shading may influence manure temperatures in tanks with small diameters at high-latitude locations. This study offers insights into understanding the relationship between manure temperatures and its thermal balance influenced by latitude, storage design, snow cover and mixing, and its implications for accurately estimating methane emissions.

Small Transjugular Intrahepatic Portosystemic Shunt Plus Variceal Embolization for Gastric Varices: A Multicenter Cohort Study

Background and AimsThe effect of transjugular intrahepatic portosystemic shunt (TIPS) plus variceal embolization for treating gastric varices (GVs) remains controversial. This nationwide multicenter cohort study aimed to evaluate whether adding variceal embolization to a small diameter (8-mm) TIPS could reduce the rebleeding incidence in patients with different types of GVs. MethodsThis retrospective cohort study involved 629 patients who underwent 8-mm TIPS for gastric varices at seven medical centers. The primary endpoint was all-cause rebleeding, and the secondary endpoints included overt hepatic encephalopathy (OHE) and all-cause mortality. ResultsA total of 629 patients were included. Among them, 429 (68.2%) had gastroesophageal varices type 1 (GOV1), 145 (23.1%) had gastroesophageal varices type 2 (GOV2), and 55 (8.7%) had isolated gastric varices type 1 (IGV1). In the entire cohort, adjunctive embolization reduced rebleeding (6.2% versus 13.6%, P=0.005) and OHE (31.0% versus 39.4%, P=0.02) compared with TIPS alone. However, no significant differences were found in mortality (12.0% versus 9.7%, P=0.42). In patients with GOV2 and IGV1, TIPS+E reduced both rebleeding (GOV2: 7.8% versus 25.1%, P=0.01; IGV1: 5.6% versus 30.8%, P=0.03) and OHE (GOV2: 31.8% versus 51.5%, P=0.008; IGV1: 11.6% versus 38.5%, P=0.04). However, in patients with GOV1, adjunctive embolization did not reduce rebleeding (5.9% versus 8.7%, P=0.37) or OHE (33.1% versus 35.3%, P=0.60). ConclusionsCompared with TIPS alone, 8-mm TIPS plus variceal embolization reduced rebleeding and OHE in patients with GOV2 and IGV1. These findings suggest that patients with GOV2 and IGV1, rather than GOV1, could benefit from embolization with TIPS.

Dynamic coupling effects of injection on spray and mixture formation in an asymmetrically vibrating combustion engine

Enhanced methods of energy conversion present a viable solution for addressing energy load challenges. This study introduces a vibrating combustion engine designed to enhance energy conversion efficiency by harnessing flexible dynamics and variable asymmetric motion. However, the consideration of its unique dynamic effects has emerged as a pivotal challenge in fuel-air mixing and combustion research. This study introduces a fuel spray and mixing simulation method that facilitates the reciprocal exchange of coupling parameters between the combustion and dynamics models. It iterates the simulation outcomes of motion and combustion to predict mixture formation. Subsequently, the method is employed to explore the impact of injection position on fuel spray and mixture formation. Results show that there is an optimum injection position for the operation frequency, and retarding or advancing leads to slow compression and weak gas motion for fuel spray and mixing, although retarded injection provides high in-cylinder gas pressure and temperature. The early injection generally causes long penetration, small droplet diameter, slight impingement, and fast evaporation, unless it is too early. The results further indicate that when IAP = 6 mm, a more uniform mixture can be attained at the beginning of combustion, leading to a thermal efficiency of up to 42.9% for the engine.

A defect contour imaging method of small diameter pipeline based on self-made three-dimensional magnetic sensor

Purpose The purpose of this paper is to use the corresponding magnetic sensor and detection method to detect and image the defects of small diameter pipelines. Urban gas pipeline is an energy transportation tool for urban industrial production and social life, which is closely related to urban safety. Preventing the occurrence of urban gas pipeline transportation accidents and carrying out pipeline defect detection are of great significance for the urban economic and social stability. To perform pipeline defect detection, the magnetic flux leakage internal detection method is generally used in the detection of large-diameter long-distance oil and gas pipelines. However, in terms of the internal detection of small-diameter pipelines, due to the heavy weight, large structure of the detection device and small pipe diameter, the detection is more difficult. Design/methodology/approach In order to solve the above matters, self-made three-dimensional magnetic sensor and three-dimensional magnetic flux leakage imaging direct method are proposed for studying the defect identification. Firstly, for adapting to the diameter range of small-diameter pipelines, and containing the complete information of the defect, a self-made three-dimensional magnetic sensor is made in this paper to improve the accuracy of magnetic flux leakage detection. And on the basis of it, a small diameter pipeline defect detection system is built. Secondly, as detection signal may be affected by background magnetic field interference and the jitter interference, the complete ensemble empirical mode decomposition with adaptive noise method is utilized to screen the detected signal. As a result, the useful signal is reconstructed and the interference signal is removed. Finally, the defect contour inversion imaging of detection is realized based on the direct method of three-dimensional magnetic flux leakage imaging, which includes three-dimensional magnetic flux leakage detection data and data segmentation recognition. Findings The three-dimensional magnetic flux leakage imaging experimental results shown that, compared to the actual defects, the typical defects, irregular defects and crack groove defects can be analyzed by the magnetic flux leakage defect contour imaging method in qualitative and quantitative way respectively, which provides a new idea for the research of defect recognition. Originality/value A three-dimensional magnetic sensor is made to adapt the diameter range of small diameter pipeline, and based on it, a small-diameter pipeline defect detection system is built to collect and display the magnetic flux leakage signal.

Morphological evaluation of adult domestic cat testicular biopsy after vitrification.

Testicular biopsies (9 mm3) from domestic cats (n = 10) submitted to orchiectomy were submitted to equilibrium vitrification in the presence of ethylene glycol (EG) alone or combined with dimethylsulfoxide (DMSO) as intracellular cryoprotectants, and sucrose or trehalose as extracellular cryoprotectants. The samples were vitrified with 40% EG or 20% EG + 20% DMSO, plus 0.1 M or 0.5 M of sucrose or trehalose. The study was divided into Step 1 and Step 2. In Step 1, intratubular cells (spermatogonia, spermatids, spermatocytes, and Sertoli cells) were quantified and classified as intact or degenerated (pyknotic and/or vacuolated cells). Cryodamage of seminiferous cords was determined by spermatogonia and Sertoli cell scoring of nuclei alterations, tubular basement membrane detachment, epithelium shrinkage, and tubular measures (total area, epithelium area, larger and smaller diameter, and height of the epithelium). In Step 2, Hoechst 33342 stain and propidium iodide (PI) fluorescent stain were used to assess the cell viability of the four best experimental groups in Step 1. The effect of treatments on all analyses was accessed using analysis of variance (ANOVA), and Fisher's post hoc test at P < 0.05 significance was considered. In Step 1, the mean percentage of spermatogonia and Sertoli cells morphological integrity did not show a difference when using both sugars at different concentrations, but their morphology was more affected when DMSO was used. EG use associated with 0.1 M of sucrose or trehalose positively affected spermatocyte and spermatid morphology, respectively. The larger diameter and epithelium height of seminiferous tubules were increased using DMSO plus 0.5 M sucrose and DMSO plus 0.1 M trehalose. The changes in spermatogonial/Sertoli nucleoli visualization were best scored in the EG groups, while the nuclei condensation was lower with sucrose. The basement membrane was satisfactorily preserved with 0.1 M sucrose. In Step 2, the percentage of cell viability was higher when EG plus 0.1 M sucrose was used. Therefore, DMSO's negative effect on the vitrification of testicular biopsies of adult domestic cats was evident. The EG plus 0.1 M of sucrose or trehalose associations are the most suitable CPAs to preserve the testicular histology structure of adult domestic cats in vitrification.

Hydrogeological characterization of low permeability medium for conceptualization of a mine site in Eastern Turkey

The mining site in Eastern Anatolia of Turkey were encounter a significant risk of slope instability within the operational area. One of the processes that govern slope stability is the pore water pressure distribution. The conceptualization and characterization of porous media serve as fundamental prerequisites for the implementation of numerical methods aimed at predicting pore water distribution. This study aims to characterize the hydrogeological properties of water bearing rocks in the active mining site in Eastern Anatolia of Turkey. A total of 21 wells and drill holes were drilled in the study area to conduct in-situ tests, monitoring, and sampling. The large diameter wells drilled in surrounding the carbonate rocks were to determine the groundwater flow and boundary conditions and also wells tapped metasediments and diorite unit for hydraulic testing. The lugeon tests and installation of vibrating wire piezometers were carried out at small diameter drill holes to obtain localized hydraulic conductivity of metasediments and diorite at different depths and monitoring pore water pressure distribution along some critical cross-sections. The results obtained from these tests are used for developing hydrogeological conceptual model for groundwater flow. The results of in-situ tests show that the metasediment and diorite units act as a single hydrostratigraphic unit. The metasediments and diorite have high total porosity and low specific yield indicating that the pore water is retained by electrostatic forces in the medium and it resists flow due to low hydraulic conductivity. The vertical variation in hydraulic conductivity values indicates that the medium is highly heterogeneous.

Laparoscopic Ultrasound-Guided Transcystic Approach for the Treatment of Common Bile Duct Stones.

Background: The treatment of choledocholithiasis with nondilated common bile duct (CBD) is a challenge for surgeons who often choose endoscopic retrograde cholangiopancreatography with laparoscopic cholecystectomy (LC) staging surgery instead of simultaneous laparoscopic CBD exploration with LC because of the small CBD diameter. This study aims to introduce and assess the clinical applicability of a technique we developed to identify and extract CBD stones using laparoscopic ultrasound (LUS). Methods: We retrospectively reviewed surgical procedures and clinical data of 13 patients who underwent LC and CBD exploration using LUS between May 2022 and August 2023. The cystic duct was used for CBD stone removal. Results: Ten patients were successfully treated; 2 patients with residual stones were treated with ursodeoxycholic acid, whereas 1 patient required a microincision near the CBD and choledochoscopy because of stone incarceration in the duodenal papilla. The CBD diameter was 6 mm (5-9 mm). There were less than three CBD stones, with diameters of 2-6 mm; the median operative time was 105 minutes (range, 52-155 minutes). One patient developed postoperative cholangitis. The median postoperative hospital stay was 6 days (3-8 days). The stone clearance rate was 76.9%, and the CBD stone detection rate was 100%. No intraoperative complications, postoperative bile leakage, and mortality occurred. Conclusions: CBD exploration and transcystic stone extraction under LUS guidance are safe and effective approaches for patients with choledocholithiasis; strict control over surgical indications is necessary. This study could provide new strategies for effectively treating choledocholithiasis.

Impact of deep learning image reconstruction on volumetric accuracy and image quality of pulmonary nodules with different morphologies in low-dose CT

BackgroundThis study systematically compares the impact of innovative deep learning image reconstruction (DLIR, TrueFidelity) to conventionally used iterative reconstruction (IR) on nodule volumetry and subjective image quality (IQ) at highly reduced radiation doses. This is essential in the context of low-dose CT lung cancer screening where accurate volumetry and characterization of pulmonary nodules in repeated CT scanning are indispensable.Materials and methodsA standardized CT dataset was established using an anthropomorphic chest phantom (Lungman, Kyoto Kaguku Inc., Kyoto, Japan) containing a set of 3D-printed lung nodules including six diameters (4 to 9 mm) and three morphology classes (lobular, spiculated, smooth), with an established ground truth. Images were acquired at varying radiation doses (6.04, 3.03, 1.54, 0.77, 0.41 and 0.20 mGy) and reconstructed with combinations of reconstruction kernels (soft and hard kernel) and reconstruction algorithms (ASIR-V and DLIR at low, medium and high strength). Semi-automatic volumetry measurements and subjective image quality scores recorded by five radiologists were analyzed with multiple linear regression and mixed-effect ordinal logistic regression models.ResultsVolumetric errors of nodules imaged with DLIR are up to 50% lower compared to ASIR-V, especially at radiation doses below 1 mGy and when reconstructed with a hard kernel. Also, across all nodule diameters and morphologies, volumetric errors are commonly lower with DLIR. Furthermore, DLIR renders higher subjective IQ, especially at the sub-mGy doses. Radiologists were up to nine times more likely to score the highest IQ-score to these images compared to those reconstructed with ASIR-V. Lung nodules with irregular margins and small diameters also had an increased likelihood (up to five times more likely) to be ascribed the best IQ scores when reconstructed with DLIR.ConclusionWe observed that DLIR performs as good as or even outperforms conventionally used reconstruction algorithms in terms of volumetric accuracy and subjective IQ of nodules in an anthropomorphic chest phantom. As such, DLIR potentially allows to lower the radiation dose to participants of lung cancer screening without compromising accurate measurement and characterization of lung nodules.