Volume Displacement Research Articles

Preventing Bird’s Beak Deformity: A narrative review of Innovations in Oncoplastic Surgery

Background: In the field of breast surgery, breast conserving surgery (BCS) is widely valued for its ability to preserve the breast while also achieving cosmetically acceptable outcomes and an overall survival rate comparable to that of total mastectomy. However, BCS has not always managed to achieved satisfactory cosmetic results. Among its challenges is the “bird’s beak” deformity, which is characterized by skin retraction and a downward deviation of the nipple areolar complex due to tissue excision from the lower pole of the breast. Methods: Various forms of oncoplastic surgery (OPS) have been developed to prevent bird’s beak deformity. These include volume displacement operations (such as superior pedicle mammoplasty, rotation technique and downward-mobilization procedure), as well as volume replacement techniques, including the latissimus dorsi mini-flap, thoracodorsal artery perforator flap, lateral intercostal artery perforator flap, anterior intercostal artery perforator flap, inframammary adipofascial flap and lipofilling. Conclusion: Choosing the most suitable approach for OPS requires careful consideration of various factors, notably the defect’s size and location, the size of the breast, and the thickness of subcutaneous fatty tissue. Further studies are required to firmly position these forms of OPS techniques in an evidence-based framework.

Numerical evaluation of the impact of sandbars on cross-shore sediment transport and shoreline evolution

Nearshore nourishments are a common intervention used to mitigate sediment deficits in coastal areas experiencing erosion problems. This coastal intervention involves placing nourished sediments in the submerged zone of the beach profile to form an artificial submerged sandbar which are then distributed by natural forces occurring in the coastal zone. Coastal processes that control the morphological evolution of coastal zones operate on several spatial and temporal scales (seconds to years) and can be divided into cross-shore and longshore components. Usually, the numerical models that simulate the evolution of cross-shore profiles due to sediment transport within the profiles, are related with short to medium-term events (days to months), and shoreline evolution models, that allow for long-term analysis (years to decades), are typically only considering longshore sediment transport. Describing all the processes in a single numerical model is complex and computationally demanding, and therefore, the numerical models are typically focused on specific processes, categorized by their temporal and spatial scales. This article presents a numerical study focused on medium to long-term numerical modelling of coastal zone evolution, examining the combined effects of cross-shore and longshore sediment transport processes of sediment transport. The model incorporates two simplified numerical models: LTC - Long Term Configuration, for shoreline evolution and CS-Model, for cross-shore sediment exchanges. Applied to nine different sandbar scenarios, model results revealed that disturbances in sandbar volume tend to return to equilibrium through cross-shore sediment transport processes. In situations that considered a constant sandbar volume alongshore, the longshore effects are null, because the volume entering in the coastal domain is equal to the volume leaving, and the sediment balance is only dependent of the cross-shore processes. Variable sandbar volume alongshore leads to impacts on shoreline position due to longshore sediment transport gradients generated by the sandbar disturbance. The results demonstrate the potential of the proposed combined model for medium to long-term projections, allowing for the interpretation of how physical aspects of nearshore nourishments evolve. These aspects include sandbar volume, shoreline position, berm width, and shoreline displacements induced by cross-shore and longshore sediment transport processes. These parameters aid in understanding sandbar-beach sediment dynamics, which is valuable for supporting coastal management, particularly in the development and design of shoreface sand nourishments, enabling the optimization of sand resources.

Structural Mastopexy: Volume Displacement in Breast Reshaping.

Although in breast reshaping, the restoration of a suitable mammary cone is the main goal of the procedure, long-lasting upper pole fullness preservation is the most common weak point of all mastopexy. Mastopexy is a challenging procedure, and a surgical procedure to create desirable long-lasting results has not been well standardized. In this paper, the authors report their experiences in structural mastopexy procedures, describing three different adipo-glandular flaps, each repositioned as auto-prosthesis to reshape upper pole contour in patients affected by a severe degree of breast ptosis. A 6-year retrospective iconographic-chart and review was performed on 89 patients undergoing mastopexy between January 2016 and December 2021. Surgical candidates reported grades 2 and 3 of ptosis following Regnault classification. Minimum follow-up was 24 months. Pre- and postoperative data for all patients were collected in the same standard conditions. 89 patients affected with bilateral breast ptosis were included in the study, for a total of 178 breasts. Patients' mean age at the time of surgery was 40.45 years, ranging between 28 and 59 years. Follow-up ranged between 2 and 6 years with an average of 47.13 months. Out of 89 patients, 50 underwent general anesthesia, and the remaining 39 underwent local anesthesia. Among the 178 treated breasts, 10 (17.8%) experienced minor complications: No major complications were reported. Autologous tissue displacement, collecting parenchyma wherever surplus can be recruited, permits the transfer of extra tissue to the lack of volume, recontouring satisfactory breast shape and ensuring long-lasting results. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Compressible ocean waves generated by sudden seabed rise near a step-type topography

A typical tsunami generation occurs through submarine earthquakes leading to large volume displacement. The corresponding mathematical problem involves modeling surface water waves generated by an arbitrary temporal motion of the ocean floor. The propagation of tsunami wave and the subsequent scattering from a sudden drop in bathymetry away from the ground motion is studied following linearized water wave theory and a weakly compressible ocean, including static oceanic background compression. The Fourier transformation and eigenfunction expansion techniques are employed to find the surface displacement and pressure profiles by leveraging appropriate matching conditions between regions of different depths. A novel energy balance relationship is derived by considering both the pure-gravity and acoustic-gravity modes. The model is validated in the limit that the depth difference approaches zero, showing a vanishing reflection contribution from the depth change. An efficient numerical code is developed that accurately captures the contribution of the cutoff frequencies of acoustic-gravity modes. Apart from the time-domain propagation of tsunami waves away from the origin, standing wave formations are observed within the shallow region, supported by significantly large pressure fluctuations in time. These standing waves or, equivalently, the pressure fluctuations sustain longer for larger ocean depth. The increase in tsunami speed in the deeper region is readily visible in the time-domain simulations. A three-dimensional axisymmetric solution is also developed, and results show a more gradual sloping tsunami wavefront compared to the equivalent two-dimensional solution for shallower depths. Animation movies corresponding to the two- and three-dimensional surface profiles are provided for better visualization.

Is Oncoplastic Surgery Safe in High-Risk Breast Cancer Phenotypes?

Oncoplastic surgery (OPS) has increased in popularity over the recent years. It is a form of breast conservation surgery allowing for larger partial mastectomy (PM) resections followed by either volume displacement or volume replacement reconstruction techniques. However, there is a lack of evidence on the effectiveness and safety of OPS with radiotherapy (OPS + RT) in high-risk breast cancer phenotypes, such as triple negative breast cancer (TNBC) and HER2 positive (HER2+) patients. Our aim was to compare the breast cancer-specific survival (BCSS) and postoperative surgical complications in OPS + RT compared to PM alone with radiation (PM + RT) and total mastectomy (MTX) without radiotherapy (MTX-RT). Patient data were analyzed from the Surveillance, Epidemiology, and End Results (SEER) cancer registries from January 1, 2012 to December 31, 2020. Patients were stratified according to the type of surgery. Cox regression analysis was performed to assess prognostic factors of BCSS. A total of 24 621 patients with high-risk breast cancer phenotypes were identified, 180 underwent OPS + RT; 13 402, PM + RT; and 11 039 MTX-RT. OPS + RT was more frequently performed in younger (mean age of 65.53 years, SD: 9.29, p < 0.001), non-Hispanic White (90.5% vs. 77.7% vs. 76.3%) and single women (17.9% vs. 12.1% vs. 13.3%). MTX-RT was usually performed in patients with high histological grade, TNBC, and higher stages. Overall complication rates were higher in the MTX-RT, compared to OPS + RT and PM + RT, 2%, 1.1%, and 0.7%, respectively, p < 0.001. Rates of hematoma and surgical site infections were higher in the MTX-RT group. With a median follow-up of 46 months, OPS + RT had better BCSS rates at 5 years compared to PM + RT and MTX-RT (97.1% vs. 94.7% vs. 89.8%, p < 0.001). MTX-RT was found to be an independent prognostic factor of worse BCSS compared to OPS + RT (hazard ratio [HR] = 2.584; 95% confidence interval [CI]: 1.005-7.171), while PM + RT had no difference compared to OPS + RT (HR = 1.670, 95% CI: 0.624-4.469). OPS is a safe breast surgical option in patients with HER2+ and TNBC. Patients with high-risk phenotypes who underwent OPS + RT and have similar BCSS and complication rates compared to standard breast surgical options. As such, OPS should be considered as an option whenever breast conservation surgery is being discussed.

The Local Rhombus-Shaped Flap-An Easy and Reliable Technique for Oncoplastic Breast Cancer Surgery and Defect Closure in Breast and Axilla.

Primarily, breast-conserving therapy is an oncological intervention, but eventually it is judged by its cosmetic result. Remaining cavities from tumor resection can promote seromas, delay healing and cause lasting discomfort. Additionally, volume loss, dislocation of nipple/areola and fat necrosis lead to (cosmetically) unfavorable results, aggravated by radiotherapy. Oncoplastic surgery can reduce these sequelae. A local flap that has rarely been used in breast cancer surgery is the Limberg rhombic flap. The tumor defect is planned as a rhombus. The sides of the rhombus are of equal length and ideally have an angle of 60° and 120°. The flap that closes the defect is planned as an extension of equal length of the short diagonal. The second incision of the flap is placed according to the defect angle of 60°, running parallel to the defect at the same length. This creates a second rhombus. The flap is transposed into the defect, and the donor area is primarily closed. It is axially perfused and safe with a 1:1 length-to-width ratio. Compared to local perforator flaps, defect closure is easily managed without microsurgical skills. In the breast, the flap can be used in volume replacement and volume displacement techniques as an all-layer flap to cover defects, or it can be deepithelialized and buried. In the axilla, it can cover full-thickness defects when skin is involved. The advantages of the rhombic flap are its safety and simplicity to add volume and close defects, thus reducing the complexity of oncoplastic surgery.

Assessing the Adequacy of Orbital Reconstruction With Titanium Mesh Using Clinical and Radiological Measures.

Background Orbital reconstruction aims to restore the original orbit volume and correct diplopia, enophthalmos, and ocular motility of the fractured orbit. This study aimed to assess the adequacy of orbital reconstruction using radiological and clinical factors. Methods In this retrospective study, patients with orbital blowout fractures meeting clinical or radiographic criteria underwent orbital reconstruction with titanium mesh. The orbital volume and anteroposterior displacement were calculated pre- and post-operatively using computed tomography. Diplopia, inferior orbital nerve examination, and ocular movement were also evaluated. Pre- and post-operative orbital volumes of the fractured and contralateral unfractured orbits were compared. Statistical analysis was performed using MS Excel (Redmond, USA) and STATA BE (Texas, US). Results There was a significant reduction in the difference in volumes between fractured and normal orbits postoperatively (p-value <0.001). The mean difference between the reconstructed orbital floor fracture and the contralateral normal orbit was 0.55 cm3, which is within the normal anatomic variation. Enophthalmos was corrected postoperatively in our patients per radiological parameters as a result of a reduction in the mean posterior displacement. Infraorbital nerve hypoesthesia was not resolved postoperatively. Conclusion Our study highlights the restoration of the normal anatomical variation in volume differences between the fractured and contralateral orbits post-surgery using CT-guided analysis, thereby improving clinical outcomes.

Tight Application of a Surgical Tourniquet Prior to Inflation Increases Venous Pressure In the Upper Limb; Potentially Resulting in Increased Blood Loss and Poorer Visibility

Tourniquets are commonly used in extremity surgery to help provide a bloodless operative field to improve visibility and reduce length of procedures. With the development of WALANT (wide awake, local anaesthetic, no tourniquet) techniques, many surgeons undertake surgery without tourniquet inflation. The correct technique of pneumatic tourniquet application is poorly understood by healthcare staff. The application of a tight tourniquet when applied for optional use or use for only a portion of a procedure, rather than for inflation throughout can cause venous engorgement of an extremity leading to increased blood loss and reduced operative field visualisation thereby discouraging surgeons from persevering with WALANT strategies. To determine the effect of tourniquet application tension on limb volume prior to skin incision. 30 volunteers had the volume of their non-dominant forearm measured post-inflation of a surgical tourniquet using two different application techniques. Tight application was defined as the tourniquet fastened using a dynamometer to a tension of 100N. Loose application was defined as the tourniquet fastened using a dynamometer to a tension of 50N. The tourniquet was then inflated to 200mmHg after both application techniques. Exsanguination was performed by elevation of the arm for 1min prior to tourniquet inflation. At 5min the forearm volume was measured using a volume displacement technique. 93% of participants (28/30) had a higher volume of water displaced when the tourniquet was applied tightly. The mean difference between the loose and tight applications was 30.06mls. The increase in volume in tightly applied tourniquets is believed to result from increased intravascular volume. This increase in blood volume can lead to increased intra-operative blood loss and poor intra-operative visualisation when operating without tourniquet inflation. Loose application of the tourniquet pre-inflation appears to prevent sequestration of venous blood in the limb, therefore decreasing operative blood loss and improving view for operating. Level 1; Symptom Prevalence Study.

Enhancing the cryogenic performance of superconducting magnet encapsulation resins with hyperbranched polymers: A molecular dynamics simulation and experimental study

Epoxy resin (EP) plays a crucial role in safeguarding superconducting magnets. One of the major concerns related to its usage is its inherent susceptibility to cracking under cryogenic temperatures and the strong electromagnetic forces experienced during the operation of superconducting magnets. In this study, we utilize molecular dynamics (MD)simulation and cryogenic experiments to conduct a comprehensive investigation aimed at gaining a profound understanding of the cryogenic toughening mechanism in hyperbranched polymers-toughened (HBPs) EPs. Five different crosslinking models of EP composites were established by MD simulations. The performance parameters obtained from the MD simulation calculations are highly consistent with the experimental results, which included the glass transition temperature, coefficient of thermal expansion, mechanical properties, free volume and atomic mean square displacement. Moreover, the relationship between structural changes and properties of the MD models was investigated. This research method provides a new avenue of exploration for superconducting magnet encapsulation resin materials.

Extreme Oncoplasty: Oncologically Safe When Compared with Mastectomy

BackgroundExtreme oncoplasty is a breast-conserving operation using oncoplastic techniques in a patient who does not meet the traditional criteria for breast conservation and in whom most physicians would suggest a mastectomy. These tumors are generally multicentric and/or multifocal, they span more than 50 mm, or they can be large recurrences in a previously irradiated breast.MethodsA prospective single institution database was queried from 2008 through mid 2023 for patients who met the criteria for extreme oncoplasty and were treated with excision plus whole-breast radiation therapy (WBRT) or mastectomy without WBRT. Patients with recurrent breast cancer were excluded. Endpoints were local, regional, and distant recurrence as well as overall and breast-cancer-specific survival.Results272 patients were treated with oncoplastic mammaplasty, using a standard or split reduction excision followed by postoperative WBRT. An additional 101 patients elected to be treated with mastectomy without postoperative radiation therapy. With a median follow-up of 7 years, there were no significant differences in local, regional, or distant recurrence, nor in breast-cancer-specific survival or overall survival.ConclusionsWe strongly support extreme oncoplasty plus WBRT as the default procedure of choice for patients with large multifocal/multicentric lesions amenable to reconstruction with volume displacement mammaplasty.

Oncoplastic Surgery Outcomes in the Older Breast Cancer Population: A Matched-Cohort Comparison Study.

Oncoplastic breast surgery (OBS) is a form of breast conservation surgery (BCS) that involves a partial mastectomy followed by immediate volume displacement or volume replacement surgical techniques. To date, there are few studies evaluating OBS in older patients. Therefore, we sought to determine if outcomes differed between patients 65 years and older versus younger patients who underwent oncoplastic surgical procedures. A retrospective chart review was performed for all oncoplastic breast operations within a single health system from 2015 to 2021. Patients were stratified by age, with patients 65 years and older (OBS65+) identified and then matched with younger patients (OBS <65) based on BMI. Primary outcomes were positive margin rates and overall complication rates; secondary outcomes were locoregional recurrence (LR), distant recurrence (DR), disease-free survival (DFS), overall survival (OS), and long-term breast asymmetry. A total of 217 patients underwent OBS over the 6-year period, with 22% being OBS65+. Preoperatively, older patients experienced higher American Anesthesia (ASA) scores, Charlson Co-morbidity index (CCI) scores, and higher rates of diabetes mellitus, hypertension, and grade 3 breast ptosis. Despite this, no significant differences were found between primary or secondary outcomes compared to younger patients undergoing the same procedures. Oncoplastic breast reconstruction is a safe option in patients 65 years and older, with overall similar recurrence rates, positive margin rates, and survival when compared to younger patients. Although the older cohort of patients had greater preoperative risk, there was no difference in overall surgical complication rates or outcomes. Supporting the argument that all oncoplastic breast reconstruction techniques should be offered to eligible patients, irrespective of age.

Method to determine envelope density for roller compacted ribbons by solid displacement of glass microspheres

The envelope density of the roll-compacted ribbon is a widely accepted physical property that serves as a criterion for the transferability of dry granulation processes. Existing methods of obtaining ribbon density data have drawbacks in their reliability and availability at production facilities. A novel method is proposed in this paper and the performance thereof is compared to other established techniques. A pilot study was conducted on several roller compactors to prepare various batches of ribbons under different process parameters using model and real formulations from the industry. The presented method measures the envelope volume of roll-compacted ribbons by solid volume displacement of glass microspheres. The solid displacement method for measuring envelope density is as precise as mercury porosimetry, provided that the ribbon quality is adequate, even in the presence of minor structural failures, it is nondestructive allowing sample reuse, and it is scalable to larger ribbon sizes.

The development of patient-specific quality assurance (PSQA) for a proton wobbling nozzle using PTSim Monte Carlo code

The aim of this study is to develop a Monte Carlo-based platform for patient-specific quality assurance (PSQA) in the proton wobbling nozzle at Chang Gung Memorial Hospital. To efficiently reduce time usage and enhance simulated precision, this platform required an initial fine-tuning of the Guard volume (GV) and lateral displacement (LD) settings. Different GV sizes combined with LD modes were utilized to estimate depth dose profiles in a water phantom. The simulated central axis depth doses were then analyzed using PTSim and compared to measurement using a PTW MP3 water tank and a Markus ionization chamber type 34045. Treatment parameters for a liver case were extracted from the Eclipse DICOM RT Plan file. Simulated doses were compared to measurements using Zebra and MatriXX systems during PSQA process. Furthermore, a geometrical trigger technique was applied to assess the track positions in patient-specific components. The study found that the mean dose difference between measured and simulated values for the optimized LD/GV was below 1% at all depth positions. With passing rates of 97.4% at the middle SOBP and 90.3% at the proximal SOBP, the gamma analysis demonstrated satisfactory results. For the axial dose profile, SOBP flatness was within 2.5%. From the geometric trigger analysis, more than 95–98% of the dose was delivered through the range compensator, while approximately 2–5% originated from scattered protons from the Multi-Leaf Collimator (MLC) and block's edges. The PTSim simulation's performance in conducting PSQA demonstrated its capability and reliability.

Directional sensitivity of bone conduction stimulation on the otic capsule in a finite element model of the human temporal bone

Sound transmission to the human inner ear by bone conduction pathway with an implant attached to the otic capsule is a specific case where the cochlear response depends on the direction of the stimulating force. A finite element model of the temporal bone with the inner ear, no middle and outer ear structures, and an immobilized stapes footplate was used to assess the directional sensitivity of the cochlea. A concentrated mass represented the bone conduction implant. The harmonic analysis included seventeen frequencies within the hearing range and a full range of excitation directions. Two assessment criteria included: (1) bone vibrations of the round window edge in the direction perpendicular to its surface and (2) the fluid volume displacement of the round window membrane. The direction of maximum bone vibration at the round window edge was perpendicular to the round window. The maximum fluid volume displacement direction was nearly perpendicular to the modiolus axis, almost tangent to the stapes footplate, and inclined slightly to the round window. The direction perpendicular to the stapes footplate resulted in small cochlear responses for both criteria. A key factor responsible for directional sensitivity was the small distance of the excitation point from the cochlea.

Investigation of performance dependence on transduction diaphragm design for piezoelectric micromachined ultrasonic transducers

One of the most important performance metrics for piezoelectric micromachined ultrasonic transducers (PMUTs) is their transmitting sensitivity, which is significantly dependent on the design of the transduction diaphragm. In this work, a comprehensive comparison of transmission sensitivities for PMUTs with circular, square, and hexagonal transduction diaphragms are investigated through theoretical calculations, finite element analysis (FEA), as well as experimental verifications. Compared to the PMUTs with circular and square transduction diaphragms, PMUTs with hexagonal transduction diaphragm can achieve greater volume displacement and hence better transmitting sensitivity as a transmitter, due to their higher fill-factor and larger quality factor (Q). The measured average resonant volume displacement and Q of 15 fabricated PMUTs with hexagonal transduction diaphragm are 3.07 × 10−13 m3/V and 798, respectively. The transmitting sensitivity of the hexagonal PMUTs exceeds that of the circular PMUTs by over 15% and that of the square PMUTs by over 3.5%. This work highlights an effective and simple approach for PMUTs to achieve high transmitting sensitivity.

Abstract PO2-22-11: 'A sledgehammer to crack a nut' or 'the safer option'? Understanding decision making for and against oncoplastic breast conserving surgery as an alternative to mastectomy in women with early breast cancer: The UK ANTHEM study

Abstract Background: Oncoplastic breast conserving surgery (OPBCS) may allow women with breast cancer to avoid mastectomy, but many women continue to choose more extensive surgery even when breast conserving options are offered. Reasons for women’s procedure choices are unclear. The UK prospective multicentre ANTHEM study (ISRCTN18238549) aimed to explore the feasibility of undertaking a large-scale multicentre study comparing the clinical and patient-reported outcomes of OPBCS as an alternative to mastectomy in women offered both options. The qualitative phase of the study aimed to use semi-structured interviews to explore women’s perceptions of choice and to understand factors influencing decision making for and against OPBCS in early breast cancer. Methods: Women offered OPBCS as an alternative to mastectomy were eligible to participate in the ANTHEM study. Participants underwent their surgical procedure of choice and were followed up for 12 months. Semi-structured interviews were conducted with a purposive sample of women who elected to undergo either OPBCS or mastectomy with or without immediate breast reconstruction (IBR) at multiple UK centres to explore perceptions of choice, rationale for decision-making, and factors influencing procedure choice. Thematic analysis was used to explore the qualitative interview data. Sampling, data collection and analysis were undertaken concurrently and iteratively until data saturation was achieved. Results: Twenty-seven women from 12 UK breast units were interviewed. Of these, 12 elected to have OPBCS with volume displacement (n=7) or replacement procedures (n=5) and 15 chose mastectomy with (n=10) or without (n=5) IBR. Overwhelmingly, women’s decisions were guided by their surgical teams and their understanding and interpretation of the information they received from them. Indeed, although provision of choice was a pre-requisite for study entry, almost a third of women didn’t feel they had been offered meaningful choice as their surgeon recommended either OPBCS or mastectomy for them. Several women described how choice was unexpected as they had automatically assumed that they would need a mastectomy and expressed delight at being offered OPBCS as an alternative. Having choice and needing to make a decision about surgery, however, was a difficult experience for some women who reported finding the process challenging. Decision-making for and against OPBCS was underpinned by women’s perceptions of three key inter-related factors based on the information they received from their surgical teams: i) the effectiveness of OPBCS at removing all the cancer; ii) perceived longer term oncological safety and iii) practical issues. Almost all women described concerns about whether all the cancer would be removed by OPBCS, the need for further surgery for involved surgical margins and anxieties about cancer recurrence over time. Women who felt reassured that OPBCS was oncologically safe were happy to accept this option. Women who remained very anxious about incomplete excision and cancer recurrence were more likely to opt for mastectomy as a ‘safer’ option. Practical issues such as the perceived magnitude of the surgery and duration of the recovery were also important with many women choosing OPBCS as a less invasive or radical option than mastectomy. While many women described preferring to keep their breast and maintaining their femininity, only a minority of women referred to the cosmetic benefits of OPBCS as influencing their decision-making. Conclusions: Women’s decision-making for OPBCS vs mastectomy for breast cancer is complex and heavily influenced by the attitudes and beliefs of their surgical team. Adequate, high-quality, accurate information about surgical options including appropriate reassurance about the short- and long-term oncological safety of OPBCS is vital if women are to make fully informed decisions and feel confident avoiding mastectomy if this is an option for them. Citation Format: Charlotte Davies, Carmel Conefrey, Nicola Mills, Patricia Fairbrother, Chris Holcombe, Lisa Whisker, Joanna Skillman, Paul White, Douglas MacMillan, Charles Comins, William Hollingworth, Shelley Potter. 'A sledgehammer to crack a nut' or 'the safer option'? Understanding decision making for and against oncoplastic breast conserving surgery as an alternative to mastectomy in women with early breast cancer: The UK ANTHEM study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-22-11.

1802: Effect of interfractional volume and motion displacement of trigone and bladder on prostate cancer

1802: Effect of interfractional volume and motion displacement of trigone and bladder on prostate cancer

Assessment of inferior pedicle therapeutic mammoplasty as apart of volume displacement techniques of oncoplastic breast surgery for early breast cancer

Assessment of inferior pedicle therapeutic mammoplasty as apart of volume displacement techniques of oncoplastic breast surgery for early breast cancer

Numerical simulation of the air-water interface effects of an airboat

This paper describes the Air-Water Interface (AWI) occurrence effects of the airboat at various speed, draught, and trim angle. This evaluates the dynamics of AWI with focus on the mechanisms involved in air displacement, the formation of air cushion, boundary layer turbulence, surface tension and wave generation. The analysis involves the change in speed, draught, and trim (0, 1, 1.5 and 2 degrees). The speed of 1.01 and 3.35m/s for displacement and planning regions of the airboat operation were examined. At the AWI, the thin layer of water molecules is affected by the airboat movement at the said trim, it is observed that the layer at the boundary will experience turbulence due to passing air over the layer and the interaction between the air and water at the interface causes mixing and creates waves or ripples at that trim. The wave generated at various trim angles will also create unique wave even at the same speed and draught with a change in trim. The difference in wave formation is seen not to be the same with the change in trim and these changes are observed at the bow and the aft of the vessel. This is also connected to the volume displacement of the boat, the resistance of the vessels, the angle of trim of the airboat and the hull form of the boat. This shows that displacement, resistance, angle of trim and hull form of the boat play critical and crucial roles in wave formation especially for the airboat.

Topology optimization structure design of shape memory alloy with multiple constraints

As an emerging functional material, shape memory alloy (SMA) exhibits remarkable mechanical properties and finds diverse applications across industries. This paper presents a topology optimization framework based on the bi-directional evolutionary structural optimization (BESO) method for designing SMA structures, which maximizes structural stiffness under multiple constraints of specified volume fraction, displacement, and fundamental frequency. A phenomenological constitutive model is utilized to simulate the mechanical behavior of SMA accurately. The unit virtual load method is employed to determine sensitivities. Several optimized SMA beam structures and simply-supported cube structures are designed under different thermal-mechanical loads, and their displacement, mean compliance, and fundamental frequency are evaluated throughout the optimization process. The results demonstrate that the proposed framework successfully customizes the SMA topology structure with adjustable displacement and fundamental frequency, and the optimized schemes exhibit more considerable deformation and more uniform mechanical properties than their initial counterparts. The proposed framework has higher computational efficiency than the traditional SIMP-based SMA topology optimization design method.