bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation Process of Urban Spatial Quality and Utility Trade-Off for Post-COVID Working Preferences
Authors: Dou Zhiyi , Qiu Waishan , Li Wenjing , Luo Dan
Published: April 2023

The formation of cities, and the relocation of workers to densely populated areas reflect a spatial equilibrium, in which the higher real consumption levels of urban areas are offset by lower non-monetary amenities [1]. However, as the society progress toward a post-COVID stage, the prevailing decentralized delivery systems and location-based services, the growing trend of working from home, with citizens’ shifting preference of de-appreciating densities and gathering, have not only changed the possible spatial distribution of opportunities, resources, consumption and amenities, but also transformed people’s preference regarding desirable urban spatial qualities, value of amenities, and working opportunities [2, 3].

This research presents a systematic method to evaluate the perceived trade-off between urban spatial qualities and urban utilities such as amenities, transportation, and monetary opportunities by urban residence in the post-COVID society. The outcome of the research will become a valid tool to drive and evaluate urban design strategies based on the potential self-organization of work-life patterns and social profiles in the designated neighbourhood.

To evaluate the subjective perception of the urban residence, the study started with a comparative survey by asking residence to compare two randomly selected urban contexts in a data base of 398 contexts sampled across Hong Kong and state their living preference under the presumption of following scenarios: 1. working from home; 2. working in city centre offices. Core information influencing the spatial equilibrium are provided in the comparable urban context such as street views, housing price, housing space, travel time to city centre, adjacency to public transport and amenities, etc. Each context is given a preference score calculated with Microsoft TrueSkill Bayesian ranking algorithm [4] based on the comparison survey of two scenarios.

The 398 contexts are further analysed via GIS and image processing, to be deconstructed into numerical values describing main features for each of the context that influence urban design strategies such as composition of spatial features, amenity allocation, adjacency to city centre and public transportations. Machine learning models are trained with the numerical values of urban features as input and two preference scores for the two working scenarios as the output. The correlation heat maps are used to identify main urban features and its p-value that influence residence’s preference under two working scenarios in post–COVID era. The same model could also be applied to inform the direction of urban design strategies to construct a sustainable community for each type of working population and validate the design strategies via predicting its competitiveness in attracting residence and developing target industries.
Developing a Hybrid Intelligence Through Hacking the Machine Learning Neural Style Transfer Process for Possible Futures
Authors: Steenblik Ralph Spencer
Published: April 2023

This article highlights work using machine learning in collaboration with designers for speculative world building. The process is unique because of the feedback loop, between the designer and the computational process. Worldbuilding is a speculative practice and requires vision and courage on the part of the designer. Working with machine learning neural style transfer (NST) allows the designers to consider possibilities humanity may not otherwise allow ourselves to imagine. This is important because human imagination paves the path for the future of humankind. Imagining a sustainable future requires considering unconventional solutions. Imagining non-probable futures allows humanity to glean desirable aspects to strive for. Even if a conceived future is impossible within the built environment, there are many opportunities for people to inhabit these environments virtually. Letting yourself get lost in these places is a form of travel, even when conditions limit one's ability to physically do so.
Using Pix2Pix to Achieve the Spatial Refinement and Transformation of Taihu Stone
Authors: Deng Qiaoming , Li Xiaofeng , Liu Yubo
Published: April 2023

Under the impact of globalization, the transformation of traditional architectural space is particularly important for the development of local architecture. As an important spatial component of traditional gardens, Taihu stone has the image characteristics of “thin, wrinkled, leaky and transparent”. The “transparency” and “ leaky” of Taihu stone reflect the connectivity and irregularity of the holes of Taihu stone, which are in line with the ideas of flowing space and transparency in contemporary architectural design. However, there are relatively few theoretical studies on the spatial analysis and design transformation of Taihu stone. The Pix2Pix model extracts the 3D spatial variation pattern by learning the variation pattern between two adjacent slices of Taihu stone. The trained Pix2Pix model can generate a series of continuous spatial sections with the spatial variation pattern of Taihu stone. Finally, the 2D sections are transformed into 3D building volumes to complete the spatial translation of Taihu stone in contemporary architectural design. In addition, this paper also provides a new idea for machine learning to master the continuous 3D spatial change pattern.
Bio-digital Sand Logics: Dune Sand Material and Computational Design
Authors: Farr Marcus
Published: April 2023

This paper discusses the creation of a new sand-based material, performative testing, and the computational logic involved in the design of a prototypical architectural system. Dune sand is known to be an unstable material compared to river or marine sand and as a result it is not normally used for construction. Because of this, desert regions have grown a reliance upon imported materials creating massive sustainability issues due to large scale global shipping, importation and resource extraction. This research indicates there is a viable opportunity to leverage dune sand as an ongoing line of inquiry for material science and design in local desert regions. It establishes that there is very little architectural research being done in this particular area. The methodology begins with experiments in bio-material using dune sand as a compound, and then establishes a construction system based upon a manifold of experiments. Along with material investigations, the process uses a Scientific Testing Method (STM) and Hypothesis in Action (HIA) as part of the testing methodology.
Ceramic Incremental Forming–A Rapid Mold-Less Forming Method of Variable Surfaces
Authors: Wang Yuxuan , Liu Yuran , Studebaker Riley , Faircloth Billie , Stuart-Smith Robert
Published: April 2023

Following architectural practice’s widespread adoption of 3D modelling software, the digital design of free-form surfaces has enabled more heterogeneously organized architectural assemblies. However, fabricating envelope components with double-curved surface geometry have remained a challenge, involving significant machine time and material waste, and great expense to produce. This proof-of-concept project proposes a rapid, low-cost, and minimal-waste approach to forming double curved ceramic components through a novel approach to Ceramic Incremental Forming (CIF), using a 6-axis industrial robot, a passive flexible mold, and a custom ball-rolling tool. The approach is comparable to Single Point Incremental Forming (SPIF) that is used for forming complex shapes with metal sheets. This method promises to achieve high-quality, ceramic building envelope components, while eliminating the need to build proprietary molds for each shape and reducing the waste in the forming process. Compared with other architectural mold-less forming methods such as clay 3D printing, the approach is more time and material efficient, while being able to achieve similar levels of complexity. Thus, CIF may offer potential for further development and industrial applications.
Research on the Spatial Layout Design of University Educational Buildings Based on Rule Screening and Multi-agent System
Authors: Zeng Yixuan , Deng Qiaoming , Liu Yubo
Published: April 2023

Unlike traditional empiricism-based building design, the data-oriented quantitative analysis method is more rigorous and intuitive, taking into account a variety of factors such as site conditions, functional requirements and design specifications, and combining computer technology to propose a more rational and efficient design strategy. This study takes the design logic process and algorithm rule screening as the entry point to explore the design method of using multi-agent body algorithm planning to realize the spatial layout of university education buildings. Based on multi-agent algorithms, spatially rich and morphologically complex architectural solutions can be quickly generated, and new designs with generality and universality can be produced by changing the initial shape and syntax rules. The authors attempt to design a program based on a multi-agent body system, where architects only need to set initial parameters to quickly construct a variety of initial volume solutions, offering a wide range of possibilities for initial design.
Heritage Information Modeling: The Case of Chellah’s Gate
Authors: Anouar S. , Anouar A. , Lharchi A.
Published: April 2023

This paper aims to propose an integrated workflow for the digitization of the built cultural heritage. To this end, we leverage the power of computational tools and the relevancy of Building Information Modeling (BIM) process to overcome the limitations and challenges faced by Scan-to-BIM. We describe the automatic generation of an as-built BIM model of a heritage building in a three-step procedure. Firstly, we outline the data acquisition method of the point cloud. Secondly, we describe the automatic processing and segmentation of the point cloud according to architectural elements using Machine Learning. Then, we tested and compared various meshing algorithms and utilized a combination depending on the desired level of details. Lastly, the resulting geometry is converted into a BIM object that will be subsequently semantically labeled. We used a UNESCO world heritage in Morocco—Chellah, as a case study to test the robustness of our protocol.
Florentine Streetscapes and their Role in Revisiting Palazzo Rucellai’s Urban façade Hypotheses
Authors: Mols Nick M. L. , Pezzica Camilla
Published: April 2023

The facciata double meaning as façade and outer appearance embodies the Italian city-state’s political, cultural, and social values that Leon Battista Alberti outlined in his famed De re aedificatoria libri decem (1485). This concept lies at the heart of Florence’s urban fabric: one of the early cradles of Renaissance architecture that originated from the artistic expenditure of prosperous families including, the Medici, Strozzi, and Rucellai. In this context, the Palazzo Rucellai (c.1446-66) marks an important historical moment in history as its façade, with its three superimposed orders and well-proportioned urban composition, was the first of its kind in Renaissance Florence. However, the palazzo’s unfinished façade sparked a debate regarding its finished appearance which the paper revisits by positioning a 3D digital twin onto the façade’s historic urban context and by applying through Space Syntax to explore its relationship to the urban fabric.
FLOURY ENDOSPERM 6 mutations enhance the sugary phenotype caused by the loss of ISOAMYLASE1 in barley
Authors: Matsushima Ryo , Hisano Hiroshi , Galis Ivan , Miura Satoko , Crofts Naoko , Takenaka Yuto , Oitome Naoko F. , Ishimizu Takeshi , Fujita Naoko , Sato Kazuhiro
Published: April 2023

Key message

Barley double mutants in two genes involved in starch granule morphology, HvFLO6 and HvISA1, had impaired starch accumulation and higher grain sugar levels than either single mutant.

Starch is a biologically and commercially important glucose polymer synthesized by plants as semicrystalline starch granules (SGs). Because SG morphology affects starch properties, mutants with altered SG morphology may be useful in breeding crops with desirable starch properties, including potentially novel properties. In this study, we employed a simple screen for mutants with altered SG morphology in barley (Hordeum vulgare). We isolated mutants that formed compound SGs together with the normal simple SGs in the endosperm and found that they were allelic mutants of the starch biosynthesis genes ISOAMYLASE1 (HvISA1) and FLOURY ENDOSPERM 6 (HvFLO6), encoding starch debranching enzyme and CARBOHYDRATE-BINDING MODULE 48-containing protein, respectively. We generated the hvflo6 hvisa1 double mutant and showed that it had significantly reduced starch biosynthesis and developed shrunken grains. In contrast to starch, soluble α-glucan, phytoglycogen, and sugars accumulated to higher levels in the double mutant than in the single mutants. In addition, the double mutants showed defects in SG morphology in the endosperm and in the pollen. This novel genetic interaction suggests that hvflo6 acts as an enhancer of the sugary phenotype caused by hvisa1 mutation.
A CFD model with free surface tracking: predicting fill level and residence time in a starve-fed single-screw extruder
Authors: Olofsson Erik Holmen , Roland Michael , Spangenberg Jon , Jokil Ninna Halberg , Hattel Jesper Henri
Published: April 2023

Mixing in extrusion is a vital part of achieving consistent and high-quality extrudates, with residence time being an elucidative measure of the mixing performance. Recent studies around numerical modeling of residence time distributions in single-screw extruders appear to consider flooded extruders mainly. This paper introduces a new and general CFD model to characterize the extruder fill length and residence time distribution for a viscoplastic ceramic material in a starve-fed extruder, including free surface tracking. The CFD model simulates a pulse-injection test, where a fluid parcel is injected at the inlet, with subsequent outlet concentration measured over time. The study includes material characterization and model validation based on laboratory tests. Results quantify the impact of accounting for the partially filled extruder instead of assuming it to be flooded, addressing the potential error when only considering simple analytical approximations to calculate system average residence times. Results further show the ability to fit simulation results to more simple analytical models. This underlines the importance of including the entire extrusion system and forming the basis for further work toward enabling real-time model predictions in starve-fed extrusion systems.
Adjoint variable method for transient nonlinear electroquasistatic problems
Authors: Ruppert M. Greta , Späck-Leigsnering Yvonne , Buschbaum Julian , De Gersem Herbert
Published: April 2023

Many optimization problems in electrical engineering consider a large number of design parameters. A sensitivity analysis identifies the design parameters with the strongest influence on the problem of interest. This paper introduces the adjoint variable method as an efficient approach to study sensitivities of nonlinear electroquasistatic problems in time domain. In contrast to the more common direct sensitivity method, the adjoint variable method has a computational cost nearly independent of the number of parameters. The method is applied to study the sensitivity of the field grading material parameters on the performance of a 320 kV cable joint specimen, which is modeled as a finite element nonlinear transient electroquasistatic problem. Special attention is paid to the treatment of quantities of interest, which are evaluated at specific points in time or space. It is shown that the method is a valuable tool to study this strongly nonlinear and highly transient technical example.
A Prospective Study of Electromyographic Amplitude Changes During Intraoperative Neural Monitoring for Open Thyroidectomy
Authors: Lian Tony , Leong David , Ng Karl , Bajenov Sonya , Sywak Mark
Published: April 2023

Background

Intraoperative nerve monitoring (IONM) of the vagus and recurrent laryngeal nerve (RLN) enables prediction of postoperative nerve function. The underlying mechanism for loss of signal (LOS) in a visually intact nerve is poorly understood. The correlation of intraoperative electromyographic amplitude changes (EMG) with surgical manoeuvres could help identify mechanisms of LOS during conventional thyroidectomy.

Methods

A prospective study of consecutive patients undergoing thyroidectomy was performed with intermittent IONM using the NIM Vital nerve monitoring system. The ipsilateral vagus and RLN was stimulated, and vagus nerve signal amplitude recorded at five time points during thyroidectomy (baseline, after mobilisation of superior pole, medialisation of the thyroid lobe, before release at Ligament of Berry, end of case). RLN signal amplitude was recorded at two time points; after medialisation of the thyroid lobe (R1), and end of case (R2).

Results

A total of 100 consecutive patients undergoing thyroidectomy were studied with 126 RLN at risk. The overall rate of LOS was 4.0%. Cases without LOS demonstrated a highly significant vagus nerve median percentage amplitude drop at medialisation of the thyroid lobe (− 17.9 ± 53.1%, P < 0.001), and end of case (− 16.0 ± 47.2%, P < 0.001) compared to baseline. RLN had no significant amplitude drop at R2 compared to R1 (P = 0.207).

Conclusions

A significant reduction in vagus nerve EMG amplitude at medialisation of the thyroid and the end of case compared to baseline indicates that stretch injury or traction forces during thyroid mobilisation are the most likely mechanism of RLN impairment during conventional thyroidectomy.
The novel anti-cancer fluoropyrimidine NUC-3373 is a potent inhibitor of thymidylate synthase and an effective DNA-damaging agent
Authors: Bré Jennifer , Dickson Alison L. , Read Oliver J. , Zhang Ying , McKissock Fiona G. , Mullen Peter , Tang Peijun , Zickuhr Greice M. , Czekster Clarissa M. , Harrison David J.
Published: April 2023

Introduction

Fluoropyrimidines, principally 5-fluorouracil (5-FU), remain a key component of chemotherapy regimens for multiple cancer types, in particular colorectal and other gastrointestinal malignancies. To overcome key limitations and pharmacologic challenges that hinder the clinical utility of 5-FU, NUC-3373, a phosphoramidate transformation of 5-fluorodeoxyuridine, was designed to improve the efficacy and safety profile as well as the administration challenges associated with 5-FU.

Methods

Human colorectal cancer cell lines HCT116 and SW480 were treated with sub-IC50 doses of NUC-3373 or 5-FU. Intracellular activation was measured by LC–MS. Western blot was performed to determine binding of the active anti-cancer metabolite FdUMP to thymidylate synthase (TS) and DNA damage.

Results

We demonstrated that NUC-3373 generates more FdUMP than 5-FU, resulting in a more potent inhibition of TS, DNA misincorporation and subsequent cell cycle arrest and DNA damage in vitro. Unlike 5-FU, the thymineless death induced by NUC-3373 was rescued by the concurrent addition of exogenous thymidine. 5-FU cytotoxicity, however, was only reversed by supplementation with uridine, a treatment used to reduce 5-FU-induced toxicities in the clinic. This is in line with our findings that 5-FU generates FUTP which is incorporated into RNA, a mechanism known to underlie the myelosuppression and gastrointestinal inflammation associated with 5-FU.

Conclusion

Taken together, these results highlight key differences between NUC-3373 and 5-FU that are driven by the anti-cancer metabolites generated. NUC-3373 is a potent inhibitor of TS that also causes DNA-directed damage. These data support the preliminary clinical evidence that suggest NUC-3373 has a favorable safety profile in patients.
Data-driven customer acceptance for attended home delivery
Authors: Köhler Charlotte , Campbell Ann Melissa , Ehmke Jan Fabian
Published: April 2023

Home delivery services require the attendance of the customer during delivery. Hence, retailers and customers mutually agree on a delivery time window in the booking process. However, when a customer requests a time window, it is not clear how much accepting the ongoing request significantly reduces the availability of time windows for future customers. In this paper, we explore using historical order data to manage scarce delivery capacities efficiently. We propose a sampling-based customer acceptance approach that is fed with different combinations of these data to assess the impact of the current request on route efficiency and the ability to accept future requests. We propose a data-science process to investigate the best use of historical order data in terms of recency and amount of sampling data. We identify features that help to improve the acceptance decision as well as the retailer’s revenue. We demonstrate our approach with large amounts of real historical order data from two cities served by an online grocery in Germany.
„Minimally invasive glaucoma surgery“ – Kammerwinkelbasierte Verfahren im Vergleich
Authors: Klabe Karsten , Rüfer Florian
Published: April 2023

In der Versorgung von Patienten mit einer Glaukomerkrankung spielen operative Verfahren eine zunehmende Rolle. Innerhalb der letzten Dekade haben sich neue chirurgische Verfahren etabliert, die unter dem Begriff „minimally invasive glaucoma surgery“ (MIGS) zusammengefasst werden. Eine große Vielfalt von unterschiedlichen Operationen zielt dabei auf die Strukturen im Kammerwinkel, sei es das Trabekelmaschenwerk und den Schlemm-Kanal zur Verbesserung des physiologischen Abflusses oder auch die Verbesserung des alternativen uveoskleralen Abflusses. Die Umsetzung des Therapieziels unterscheidet sich bei den einzelnen Verfahren ebenso wie die maximal erreichbare Drucksenkung. Im Vergleich zur Trabekulektomie mit dem Einsatz von Zytostatika ist die erzielbare Drucksenkung in der Regel deutlich geringer. Als Vorteil dieser Verfahren werden hingegen die signifikant geringeren intra- und postoperativen Komplikationsraten betont. Mit zunehmender klinischer Erfahrung und dem Anwachsen von suffizienten Daten dieser neuen chirurgischen Verfahren fällt eine fundierte Einordnung in den Behandlungsalgorithmus der Glaukomchirurgie leichter. Dennoch bleibt die letztendliche Entscheidung für einen einzelnen Eingriff aufgrund der geringen Differenzen hinsichtlich Wirksamkeit und Sicherheitsprofil häufig an die persönlichen Präferenzen des Chirurgen gebunden.
µPIV measurements of the phase-averaged velocity distribution within wavy films
Authors: Metzmacher Andreas , Burgmann Sebastian , Janoske Uwe
Published: April 2023

Thin-film flows are frequently used in process engineering and are therefore of great interest in research. In most cases, waves occur which have a positive effect on the material and heat transport and significantly influence the dynamics of the film flow. A combination of µ-particle image velocimetry and confocal chromatic distance measurement is used to measure phase-averaged flow velocities in naturally developed film waves. A trigger signal is sent to the PIV system and a recording starts when a wave reaches the wave crest threshold. This makes it possible to trigger the µPIV system depending on the film thickness. The focus of this work is on the triggering of the wave crest. The functionality and quality of the measurements depend on the correct positioning of the confocal chromatic sensor, with the light spot at the level of the camera section. Simultaneously, the minimum, average, and maximum film thickness, as well as the wave amplitude and wave frequency, are recorded. Film flow is investigated on a glass plate at various angles (5°, 10°, 15°) of inclination, Reynolds numbers (30-200), and measurement positions. The results are compared with the theoretical solutions according to Nusselt. In addition, the influence of the tilt angle and the measuring position is explained. The measuring position, in particular, has a non-negligible influence since the characteristics of the film flow are largely dependent on the streamwise measuring position. Compared to the theoretical solutions according to Nusselt, the velocities and film thicknesses are significantly greater due to the presence of the waves. With increasing inclination angle and streamwise measuring position, the measured mean and maximum velocities of the film flow increase. They almost double when the inclination angle increases from 5° to 15°. When comparing the velocities depending on the measuring position (300–500 mm), it is noticeable that the velocities increase between 5 and 15%, depending on the angle, due to wave development and gravity.
MELD-score for risk stratification in cardiac surgery
Authors: Pathare Presheet , Elbayomi Mohamed , Weyand Michael , Griesbach Colin , Harig Frank
Published: April 2023

The outcome of the patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) is also influenced by the renal and hepatic organ functions. Risk stratification, using scores such as EURO Score II or STS Short-Term Risk Calculator for patients undergoing cardiac surgery with cardiopulmonary bypass, ignores the quantitative renal and hepatic function; therefore, MELD-Score was applied in these cases. We retrospectively examined patient data using the MELD score as a predictor of mortality. To perform a univariate analysis of the data, patients were classified into three groups based on the MELD Score: MELD < 10 (Group 1), MELD 10 to 19 (Group 2), and MELD ≥ 20 (Group 3). A total of 11,477 participants were included in the study, though several patients with either missing MELD scores or lack of creatinine, bilirubin, or INR levels were dropped from the original cohort. Eventually, 10,882 patients were included in the analysis. The primary outcome was defined as postoperative, in-hospital mortality. Secondary outcomes such as postoperative bleeding, including the requirement for repeat thoracotomy, postoperative neurological complications, and assessment of catecholamines on weaning from cardiopulmonary bypass/ requirement of mechanical circulatory support were examined. A higher MELD score was associated with increased postoperative mortality. Patients with MELD > 20 experienced a 31.2% postoperative mortality, compared to Group 1 (4.6%) and Group 2 (17.5%). The highest rates of postoperative bleeding (13.8%) and, repeat thoracotomy (13.2%) & postoperative pneumonia (17.4%) were seen in Group 3 (threefold increase when compared to Group 1, renal failure requiring dialysis (N = 235, 2.7% in Group 1 v/s N = 78, 22.9% in Group 3) or requiring high dose catecholamines post-operatively or mechanical circulatory support (IABP/ECLS). Incidentally, an increased MELD Score was not associated with a significant increase in the postoperative incidence of stroke/TIA or the presence of sternal wound infections/complications. A higher mortality was observed in patients with reduced liver and renal function, with a significant increase in patients with a MELD score > 20. As the current risk stratification scores do not consider this, we recommend applying the MELD score before considering patients for cardiac surgery.
Improved forecast of 2015/16 El Niño event in an experimental coupled seasonal ensemble forecasting system
Authors: Ray Sulagna , Stefanova Lydia , Fu Bing , Guan Hong , Wang Jiande , Meixner Jessica , Mehra Avichal , Zhu Yuejian
Published: April 2023

To improve NOAA’s seasonal forecasting capabilities, a new coupled system within the Unified Forecast System (UFS) framework is being developed through a community-wide effort led by NOAA’s Environmental Modeling Center targeting the configuration of a future operational Seasonal Forecast System (SFS v1). An experimental version of this ensemble seasonal forecasting system is tested on forecasting the strong El Niño of 2015/16. The then-operational systems and NCEP real-time seasonal forecasts (CFSv2) underestimated its strength towards the end of 2015 and beginning of 2016. In addition to perturbing the atmospheric initial conditions, run-time stochastic physics-based perturbations are applied in both atmosphere and ocean components of this new coupled system to represent the model uncertainties. The UFS ensembles are initialized on June 1st, 2015 and run through a 9-month period. Compared to CFSv2, the forecast of Niño 3.4 SST and intra-seasonal zonal windstress for the 2015/16 El Niño in the UFS system are improved, as is the ensemble spread. A cold SST forecast error develops in the central equatorial Pacific, likely from excess evaporative cooling, shallower thermocline, and an excessively strong vertical current shear driven cooling. Near the eastern equatorial Pacific coast, on the other hand, warm surface and cool subsurface errors persist from initialization until the end of the forecast. The results suggest that further improvement in the seasonal forecast may be achieved by a combination of factors, including, but not limited to, improving the coupled system initialization, along with the atmospheric physics.
Appendectomy as part of Ladd’s procedure: a systematic review and survey analysis
Authors: Al Smady Montaser Nabeeh , Hendi Salama Bin , AlJeboury Sarah , Al Mazrooei Hessa , Naji Hussein
Published: April 2023

Background

Ladd’s Procedure has been the surgical intervention of choice in the management of congenital intestinal malrotation for the past century. Historically, the procedure included performing an appendectomy to prevent future misdiagnosis of appendicitis, since the location of the appendix will be shifted to the left side of the abdomen. This study consists of two parts. A review of the available literature on appendectomy as part of Ladd’s procedure and then a survey sent to pediatric surgeons about their approach (to remove the appendix or not) while performing a Ladd’s procedure and the clinical reasoning behind their approach.

Methods

The study consists of 2 parts: (1) a systematic review was performed to extract articles that fulfill the inclusion criteria; (2) a short online survey was designed and sent by email to 168 pediatric surgeons. The questions in the survey were centered on whether a surgeon performs an appendectomy as part of the Ladd’s procedure or not, as well as their reasoning behind either choice.

Results

The literature search yielded five articles, the data from the available literature are inconsistent with performing appendectomy as part of Ladd's procedure. The challenge of leaving the appendix in place has been briefly described with minimal to no focus on the clinical reasoning. The survey demonstrated that 102 responses were received (60% response rate). Ninety pediatric surgeons stated performing an appendectomy as part of the procedure (88%). Only 12% of pediatric surgeons are not performing appendectomy during Ladd’s procedure.

Conclusion

It is difficult to implement a modification in a successful procedure like Ladd’s procedure. The majority of pediatric surgeons perform an appendectomy as part of its original description. This study has identified gaps in the literature pertaining to analyze the outcomes of performing Ladd's procedure without an appendectomy which should be explored in future research.
The corticocancellous press fit iliac crest bone dowel for recalcitrant scaphoid nonunion: analysis of union rate and clinical outcome
Authors: Schäfer Ruth Christine , Nusche Andreas , Einzmann Anna , Illg Claudius , Daigeler Adrien , Rachunek Katarzyna
Published: April 2023

Introduction

Scaphoid nonunion after failed primary treatment remains challenging particularly when entailed by bone loss, avascular necrosis or deformity. We describe a scaphoid augmentation and fixation technique for cases of recalcitrant nonunion after screw placement by autologous press fit corticocancellous dowel. This study aims to provide reliable data on clinical and radiological outcomes and to contextualize in the face of other treatment options.

Material and methods

The study included 16 patients with recalcitrant nonunion of the scaphoid. All patients received screw removal and scaphoid reconstruction by a dowel shaped non-vascularized corticocancellous bone graft from the iliac crest facilitating packing of the screw channel. Bone union, the scapholunate, radiolunate and intrascaphoidal angles were evaluated on X-ray and CT images, range of motion noted. Additionally grip strength, DASH and Green O’Brien scores were obtained from eight patients.

Results

A union rate of 73% was noted after mean follow-up of 54 months. After revisional reconstruction of the scaphoid an extension–flexion rate of 84% of the healthy side was noted while pronation-supination reached 101%. DASH score averaged at 2.9, rest pain on a numeric rating scale was 0.43 with 99% peak grip force of the healthy side.

Conclusion

In complex cases of revisional scaphoid nonunion after screw placement, the corticocancellous iliac crest pressfit dowel is an option for augmentation and stabilization of the scaphoid by preserving the articular surface.

Level of evidence

IV, retrospective case series.
Effect of different surgical routes on pregnancy outcome of history-indicated cervical cerclage
Authors: Qin Feng , Yang Yong , Zhou Wei , Chi Yugang , Liu Bao , Chen Gongli
Published: April 2023

Objective

To study the guiding significance of medical history on laparoscopic and vaginal cervical cerclage in the treatment of cervical incompetence and its influence on pregnancy outcome.

Methods

A total of 53 cases by laparoscopic abdominal cervical cerclage (LAC group) before pregnancy and 73 cases by transvaginal cervix cerclage (TVC group) at 12–14 weeks of pregnancy were collected. Multivariate logistic regression analysis was performed on the influencing factors of delivery gestational weeks. Furthermore, the gestational weeks after cervical cerclage were compared between the two groups with high- and low-risk grades.

Results

The number of previous uterine cavity operations in LAC group was more than that TVC group, and the costs of operation were more than TVC group. At the same time, the hospitalization days and operation time were longer than those in TVC group, and the delivery rate of cesarean section was higher than TVC group, but the total hospitalization times were less than TVC group (P < 0.05). The rate of delivery before 34 weeks of pregnancy and the incidence of premature rupture of membranes or premature labor in LAC group were lower than those in TVC group (P < 0.05). In TVC group, the increased number of prior PTB or STL and the history of cervical cerclage failure would increase the risk of premature delivery before 34 weeks of pregnancy. There was no increased risk of preterm delivery before 34 weeks of pregnancy in LAC group (P > 0.05). According to the risk level, in the high-risk group, the delivery rate of LAC group at gestational weeks < 37 weeks, < 34 weeks and < 28 weeks was lower than that of TVC group.

Conclusion

Laparoscopic cervical cerclage might be more effective in preventing premature delivery before 34 weeks of gestation, and its influence on delivery gestational weeks was not affected by related medical history. For high-risk patients with the history of prior PTB or STL and failed cerclage, laparoscopic cervical cerclage might be more effective than vaginal cervical cerclage in preventing extremely preterm before 28 weeks, premature delivery before 34 weeks and premature delivery before 37 weeks. Therefore, our limited experience suggested that LAC can be a recommended option for patients with high-risk history.
Translocator protein (TSPO)-PET as diagnostic and monitoring tool in COVID-19 related MRI-negative brainstem encephalitis: a case report
Authors: Wischmann Johannes , Bartos Laura M. , Brendel Matthias , Albert Nathalie L. , Forbrig Robert , Straube Andreas , Masouris Ilias
Published: April 2023

Background

Encephalitis and myelitis have been linked to both COVID-19 vaccination and infection, causing symptoms such as reduced consciousness, mental state alterations and seizures. Remarkably, most cases do not show significant structural alterations on MRI scans, which poses a diagnostic challenge.

Methods

We present the diagnostic workup and clinical course of a patient who developed a progressive brainstem syndrome two weeks after COVID-19 vaccination and subsequent infection. We used translocator protein (TSPO)-PET scans for the first time to investigate COVID-related neuroinflammation.

Results

The patient developed oculomotor disorder, dysarthria, paresthesia in all distal limbs and spastic-atactic gait. CSF analysis revealed mild lymphocytic pleocytosis with normal protein levels. Brain and spinal cord MRI scans were negative, but TSPO/PET scans showed increased microglia activity in the brainstem, which correlated with the clinical course. Steroid treatment led to clinical improvement, but relapse occurred during prednisone taper after four weeks. Plasmapheresis had no significant effect; however, complete remission was achieved with cyclophosphamide and methotrexate, with normal TSPO signal ten months after onset.

Conclusions

TSPO-PET can be a valuable tool in the diagnostic and therapeutic monitoring of COVID-19-related encephalitis, particularly in cases where MRI scans are negative. Aggressive immunosuppressive therapy can lead to sustained remission.
Predictors for selective flexure mobilization during robotic anterior resection for rectal cancer: a prospective cohort analysis
Authors: Meyer Jeremy , van der Schelling George , Wijsman Jan , Ris Frédéric , Crolla Rogier
Published: April 2023

Introduction

Splenic flexure mobilization (SFM) may be indicated during anterior resection to provide a tension-free anastomosis. However, to date, no score allows identifying patients who may benefit from SFM.

Methods

Patients who underwent robotic anterior resection for rectal cancer were identified from a prospective register. Demographic and cancer-related variables were extracted, and predictors of SFM were identified using regression models. Thereafter, 20 patients with SFM and 20 patients without SFM were randomly selected and their pre-operative CTscan were reviewed. The radiological index was defined as 1/(sigmoid length/pelvis depth). The optimal cut-off value for predicting SFM was identified using ROC curve analysis.

Results

Five hundred and twenty-four patients were included. SFM was performed in 121 patients (27.8%) and increased operative time by 21.8 min (95% CI: 11.3 to 32.4, p < 0.001). The incidence of postoperative complications did not differ between patient with or without SFM. Realization of an anastomosis was the main predictor for SFM (OR: 42.4, 95% CI: 5.8 to 308.5, p < 0.001). In patients with colorectal anastomosis, both sigmoid length (15 ± 5.1 cm versus 24.2 ± 80.9 cm, p < 0.001) and radiological index (1 ± 0.3 versus 0.6 ± 0.2, p < 0.001) differed between patients who had SFM and patients who did not. ROC curve analysis of the radiological index indicated an optimal cut-off value of 0.8 (sensitivity: 75%, specificity: 90%).

Conclusion

SFM was performed in 27.8% of patients who underwent robotic anterior resection, and increased operative time by 21.8 min. For optimal surgical planning, patients requiring SFM can be identified based on pre-operative CT using the index 1/(sigmoid length/pelvis depth) with a cut-off value set at 0.8.
A Meso/Macroscale Theoretical Model for Investigating the Large Deformation of Soft Rock Tunnels Considering Creep and Anisotropic Effects
Authors: Xia Chang , Liu Zhen , Zhou Cuiying , Zhang Lihai
Published: April 2023

The rheological deformation of soft rock resulting from tunnel excavation can lead to significant construction and safety challenges. In this study, a multiphase numerical model was developed to simulate the rheological deformation of soft rock surrounding a tunnel after excavation. The developed model considers the coupled meso/macroscale creep and damage processes of the rock using the coupled discrete element method–finite element method (DEM–FEM). In particular, the damage and deformation accumulation at the mesoscale (i.e., initial phase before excavation, loading phase due to the disturbance of the excavation and creep-induced damage phase leading to large deformation) were incorporated into the model. The model predictions were validated using field monitoring data. By incorporating the coupled meso/macroscale deformation process of the rock into the model, the predicted time-dependent displacements of the tunnel face agree reasonably well with the monitoring data. In addition, the results demonstrate that tunnel brittle damage accumulated in mineral clusters severely leads to instantaneous deformation, which becomes less important in the creep evolution stage. Furthermore, the results indicate that the final deformation is characterized by a high sensitivity to the value of mesoscale modeling parameters.
Early-Time Shut-In for Plane-Strain Hydraulic Fractures
Authors: Liu Dong
Published: April 2023

One investigates the post-shut-in growth of a plane-strain hydraulic fracture in an impermeable medium while accounting for the possible presence of a fluid lag. After the stop of fluid injection, the fracture may present three distinct propagation patterns: an immediate arrest, a temporary arrest with delayed propagation, and a continuous fracture growth. These three patterns are all followed by a final fracture arrest yet the fracture behaviour prior to that results from the interplay between the dimensionless toughness $$\mathcal {K}_m$$

K
m

, the shut-in time $$t_s/t_{om}$$

t
s

/

t

om

, and the propagation time $$t/t_s$$

t
/

t
s

. $$\mathcal {K}_m$$

K
m

characterizes the energy dissipation ratio between fracture surface creation and viscous fluid flow under constant rate injection. $$t_s$$

t
s

and $$t_{om}$$

t

om

represent respectively the timescale of shut-in and the coalescence of the fluid and fracture fronts. The immediate arrest occurs when the fracture toughness dominates the fracture growth at the stop of injection ($$\mathcal {K}_m \gtrapprox 4.3$$

K
m

⪆
4.3

). It may also occur upon an early shut-in at low dimensionless toughness associated with an overshoot of fracture extension and a significant fluid lag. For intermediate values of $$\mathcal {K}_m$$

K
m

and $$t_s/t_{om}$$

t
s

/

t

om

, the fracture may experience a temporary arrest followed by a restart of fracture propagation. The period of the temporary arrest becomes shorter with higher dimensionless toughness and later shut-in until it drops to zero. The fracture behaviour after shut-in then transitions from temporary arrest to continuous propagation. These propagation patterns result in different evolution of fracture dimensions which possibly explains the various emplacement scaling relations reported in magmatic dikes.
Clinical usefulness of metagenomic next-generation sequencing for Rickettsia and Coxiella burnetii diagnosis
Authors: Zhang Xuan , Chen Huixin , Han Dongsheng , Wu Wei
Published: April 2023

Rickettsia and Coxiella burnetii are zoonotic tick-borne pathogens that cause febrile illnesses in humans. Metagenomic next-generation sequencing (mNGS) is a new technology used to diagnose infectious diseases. However, clinical experience with applying the test to rickettsioses and Q fever is relatively limited. Therefore, this study aimed to explore the diagnostic performance of mNGS in detecting Rickettsia and C. burnetii. We retrospectively studied patients with rickettsioses or Q fever between August 2021 and July 2022. Peripheral blood mNGS and polymerase chain reaction (PCR) were performed for all patients. Clinical data were retrieved for analysis. Thirteen patients were included in this study (eleven confirmed cases and two suspected cases). Signs and symptoms included fever (13, 100%), rash (7, 53.8%), muscle soreness (5, 38.5%), headache (4, 30.8%), skin eschar (3, 23.1%), and disturbance of consciousness (2, 15.4%). In addition, eight patients (61.6%) had thrombocytopenia, ten (76.9%) had liver function impairment, and two (15.4%) had renal function impairment. The results of mNGS revealed seven patients with R. japonica (53.8%), five with C. burneti (38.5%), two with R. heilongjiangensis (15.4%), and one with R. honei (7.7%). PCR results were positive in 11 patients (84.6%). After receiving doxycycline-based treatment, 12 (92.3%) patients returned to a normal temperature within 72 h. All patients were discharged in better health. Therefore, mNGS can help diagnose Rickettsia and C. burnetii and shorten the diagnosis time, especially for patients with atypical clinical manifestations and unclear epidemiologic evidence of a tick bite or exposure.
Incidence and risk factors for venous thromboembolism in the Cancer-VTE Registry stomach cancer subcohort
Authors: Yoshikawa Takaki , Sano Takeshi , Terashima Masanori , Yamaguchi Kensei , Bando Etsuro , Kawabata Ryohei , Yabusaki Hiroshi , Shinohara Hisashi , Oba Mari S. , Kimura Tetsuya , Takita Atsushi , Sasako Mitsuru
Published: April 2023

Background

The Cancer-VTE Registry was a large-scale, multicenter, prospective registry designed to investigate real-world data on venous thromboembolism (VTE) incidence and risk factors in adult Japanese patients with solid tumors. This pre-specified subgroup analysis aimed to estimate the incidence of VTE, including VTE types other than symptomatic VTE, and identify risk factors of VTE in stomach cancer from the Cancer-VTE Registry.

Methods

Stage II–IV stomach cancer patients who planned to initiate cancer therapy and underwent VTE screening within 2 months before registration were enrolled.

Results

Of 1,896 patients enrolled, 131 (6.9%) had VTE at baseline, but 96.2% were asymptomatic. Female sex, age ≥ 65 years, VTE history, and D-dimer > 1.2 μg/mL were independent risk factors of VTE at baseline. Notably, patients with D-dimer > 1.2 µg/mL at the time of cancer diagnosis had an approximately 20-fold risk of VTE. During follow-up, event incidences were symptomatic VTE, 0.3%; incidental VTE requiring treatment, 1.1%; composite VTE, 1.4%; bleeding, 1.6%; cerebral infarction/transient ischemic attack/systemic embolic events, 0.7%; and all-cause death, 15.0%. The incidence of all-cause death was higher in patients with VTE vs without VTE at baseline (adjusted hazard ratio 1.67; 95% confidence interval 1.21–2.32; p = 0.002).

Conclusions

VTE prevalence at the time of cancer diagnosis was not negligible and was extremely high when the patients had high D-dimer. VTE screening by D-dimer before starting cancer treatment is advisable, even for asymptomatic patients, regardless of whether the patient is undergoing surgery or chemotherapy.

Trial registration

UMIN000024942.