Mean Distance Research Articles

Measurement of distances and locations of thoracic and lumbar vertebral bodies from CT scans in cases of spinal deformation

BackgroundSpinal deformations, except for acute injuries, are among the most frequent reasons for visiting an orthopaedic specialist and musculoskeletal treatment in adults and adolescents. Data on the morphology and anatomical structures of the spine are therefore of interest to orthopaedics, physicians, and medical scientists alike, in the broad field from diagnosis to therapy and in research.MethodsAlong the course of developing supplementary methods that do not require the use of ionizing radiation in the assessment of scoliosis, twenty CT scans from females and males with various severity of spinal deformations and body shape have been analysed with respect to the transverse distances between the vertebral body and the spinous process end tip and the skin, respectively, at thoracic and lumbar vertebral levels. Further, the locations of the vertebral bodies have been analysed in relation to the patient’s individual body shape and shown together with those from other patients by normalization to the area encompassed by the transverse body contour.ResultsWhile the transverse distance from the vertebral body to the skin varies between patients, the distances from the vertebral body to the spinous processes end tips tend to be rather similar across different patients of the same gender. Tables list the arithmetic mean distances for all thoracic and lumbar vertebral levels and for different regions upon grouping into mild, medium, and strong spinal deformation and according to the range of spinal deformation.ConclusionsThe distances, the clustering of the locations of the vertebral bodies as a function of the vertebral level, and the trends therein could in the future be used in context with biomechanical modeling of a patient’s individual spinal deformation in scoliosis assessment using 3D body scanner images during follow-up examinations.

Radar localization of breast and axillary lesions with SCOUT: a prospective single institution pilot study.

Wire-guided localization has been the mainstay of localization techniques for non-palpable breast and axillary lesions prior to excision. Evidence is still growing for relatively newer localization technologies. This study evaluated the efficacy of the wireless localization technology, SCOUT®, for both breast and axillary surgery. Data were extracted from a prospective database (2021-2023) of consecutive patients undergoing wide local excision, excisional biopsy, targeted axillary dissection, or axillary lymph node dissection with SCOUT at a high-volume tertiary centre. Rates of successful reflector placement, intraoperative lesion localization, and reflector retrieval were evaluated. A survey of surgeon-reported ease of lesion localization and reflector retrieval was also evaluated. ACTRN386751. One-hundred-ninety-five reflectors were deployed in 172 patients. Median interval between deployment and surgery was 3 days (range 1-20) and mean distance from reflector to lesion was 3.2 mm (standard deviation, SD 3.1). Rate of successful localization and reflector retrieval was 100% for both breast and axillary procedures. Mean operating time was 65.8 min (SD 33). None of the reflectors migrated. No reflector deployment or localization-related complications occurred. Ninety-eight percent of surgeons were satisfied with ease of localization for the first half of cases. SCOUT is an accurate and reliable method to localize and excise both breast and axillary lesions, and it may overcome some of the limitations of wire-guided localization.

Extralimital terrestrials: A reassessment of range limits in Alaska's land mammals.

Understanding and mitigating the effects of anthropogenic climate change on species distributions requires the ability to track range shifts over time. This is particularly true for species occupying high-latitude regions, which are experiencing more extreme climate change than the rest of the world. In North America, the geographic ranges of many mammals reach their northernmost extent in Alaska, positioning this region at the leading edge of climate-induced distribution change. Over a decade has elapsed since the publication of the last spatial assessments of terrestrial mammals in the state. We compared public occurrence records against commonly referenced range maps to evaluate potential extralimital records and develop repeatable baseline range maps. We compared occurrence records from the Global Biodiversity Information Facility for 61 terrestrial mammal species native to mainland Alaska against a variety of range estimates (International Union for Conservation of Nature, Alaska Gap Analysis Project, and the published literature). We mapped extralimital records and calculated proportions of occurrences encompassed by range extents, measured mean direction and distance to prior range margins, evaluated predictive accuracy of published species models, and highlighted observations on federal lands in Alaska. Range comparisons identified 6,848 extralimital records for 39 of 61 (63.9%) terrestrial mainland Alaskan species. On average, 95.5% of Alaska Gap Analysis Project occurrence records and ranges were deemed accurate (i.e., > 90.0% correct) for 31 of 37 species, but overestimated extents for 13 species. The International Union for Conservation of Nature range maps encompassed 68.1% of occurrence records and were > 90% accurate for 17 of 39 species. Extralimital records represent either improved sampling and digitization or actual geographic range expansions. Here we provide new data-driven range maps, update standards for the archiving of museum-quality locational records and offer recommendations for mapping range changes for monitoring and conservation.

Course and Relation of the Facial Vessels-An Anatomical Study.

Background and Objectives: Facial vascular anatomy plays a pivotal role in both physiological context and in surgical intervention. While data exist on the individual course of the facial artery and vein, to date, the spatial relationship of the vasculature has been ill studied. The aim of this study was to assess the course of facial arteries, veins and branches one relative to another. Materials and Methods: In a total of 90 halved viscerocrania, the facial vessels were injected with colored latex. Dissection was carried out, the relation of the facial vessels was studied, and the distance at the lower margin of the mandible was measured. Furthermore, branches including the labial and angular vessels were assessed. Results: At the base of the mandible, the facial artery was located anterior to the facial vein in all cases at a mean distance of 6.2 mm (range 0-15 mm), with three cases of both vessels adjacent. An angular vein was present in all cases, while an angular artery was only present in 34.4% of cases. Conclusions: The main trunk of the facial artery and vein yields a rather independent course, with the facial artery always located anterior to the vein, while their branches, especially the labial vessels, demonstrate a closer relationship.

The last of the maculineans: can we save the emblematic Alcon Blue butterfly Phengaris alcon under climate change when its habitat continues to deteriorate?

In the NW-European region of Flanders (northern Belgium), wet heathlands harbour several threatened species among which the emblematic Alcon Blue butterfly Phengaris alcon is rapidly declining. Since 1990, the number of occupied grid cells in Flanders has decreased from 61 to only six in 2023, a decline of 90%. Due to the loss of many populations, the mean distance between populations tripled from 9 km in the period 1950–1990 to 27 km now. Site-wide egg counts in one of the strongholds of the Alcon Blue in Flanders revealed a strong increase after some initial intensive care conservation measures in the 2000s, but since 2013 a steep decline of 99% has been observed. The standardised egg counts in the remaining six Flemish populations (i.e., monitoring within the framework of the Natura2000 reporting) showed a yearly decrease of 18% since 2016. Despite increased conservation attention and targeted management since the end of the 1990s, the current situation of P. alcon in Belgium is more precarious than ever. Causes of this rapid decline are manifold and they are likely to be amplified by extreme weather conditions caused by climate change. More efficient intensive care measures and more intense cooperation across national borders are now quickly required to regionally preserve this habitat specialist with a unique eco-evolutionary profile.Implications for insect conservation By analysing the causes of the decline of the threatened Alcon Blue butterfly in Flanders, we suggest management and policy measures in an attempt to conserve this and other threatened heathland species in a highly anthropogenic region.

Performance of the Applied Biosystems HIV-1 Genotyping Kit with Integrase.

HIV genotyping is used to assess HIV susceptibility to antiretroviral drugs. The Applied Biosystems HIV-1 Genotyping Kit with Integrase (AB kit, Thermo Fisher Scientific) detects resistance-associated mutations (RAMs) in HIV protease (PR), reverse transcriptase (RT), and integrase (IN). We compared results from the AB kit with results obtained previously with the ViroSeq HIV-1 Genotyping System. DNA amplicons from the AB kit were also analyzed using next-generation sequencing (NGS). HIV RNA was extracted using the MagNA Pure 24 instrument (Roche Diagnostics; 96 plasma samples, HIV subtype B, viral load range: 530-737,741 copies/mL). FASTA files were generated from AB kit data using Exatype (Hyrax Biosciences). DNA amplicons from the AB kit were also analyzed by NGS using the Nextera XT kit (Illumina). Drug resistance was predicted using the Stanford HIV Drug Resistance Database. The mean genetic distance for sequences from ViroSeq and the AB kit was 0.02% for PR/RT and 0.04% for IN; 103 major RAMs were detected by both methods. Four additional major RAMs were detected by the AB kit only. These four major RAMs were also detected by NGS (detected in 18.1%-38.2% of NGS reads). NGS detected 27 major RAMs that were not detected with either of the Sanger sequencing-based kits. All major RAMs detected with ViroSeq were detected with the AB kit; additional RAMs were detected with the AB kit only. DNA amplicons from the AB kit can be used for NGS for more sensitive detection of RAMs.

The Safety of Volar to Dorsal Percutaneous Screw Fixation of Bennett Fracture-Dislocation - A Cadaveric Study.

Background: Bennett fractures are traditionally fixed with percutaneous K-wires from dorsal to volar, or with a volar to dorsal screw via a volar open approach. While volar to dorsal screw fixation is biomechanically advantageous, an open approach requires extensive soft tissue dissection, thus increasing morbidity. This study aims to investigate the practicality and safety of Bennett fracture fixation using a percutaneous, volar to dorsal screw, particularly with regard to the median nerve and its motor branch during wire and screw insertion. Methods: Fifteen fresh frozen forearm and hand specimens were obtained from the University of Auckland human cadaver laboratory. A guidewire is placed under image intensifier from volar to dorsal with the thumb held in traction, abduction and pronation. The wire is passed through the skin volarly under image intensifier, then the median nerve is dissected from the carpal tunnel and the motor branch of the median nerve (MBMN) is dissected from its origin to where it supplies the thenar musculature. The distance between the K-wire to the MBMN is measured. Results: In 14 of 15 specimens, the wire was superficial and radial to the carpal tunnel. The mean distance to the origin of the MBMN is 6.2 mm (95% CI 4.1-8.3) with the closest specimen 1 mm away. The mean closest distance the wire gets to any part of the MBMN is 3.7 mm (95% CI 1.6-5.8); in two specimens, the wire was through the MBMN. Conclusions: Wire placement, although done under image intensifier, is subject to significant variation in exiting location. While research has shown the thenar portal in arthroscopic thumb surgery is safe, our guidewire needs to exit further ulnar to capture the Bennett fracture fragment, placing the MBMN at risk. This cadaveric study has demonstrated the proposed technique is unsafe for use.

Anatomic considerations during placement of mandibular retromolar miniplates for orthodontic anchorage – A study of the characteristics of retromolar fossa

Objectives: The mandibular retromolar area offers a novel site for orthodontic skeletal anchorage. It houses the retromolar foramen (RMF), and surgical interventions in this area can lead to undesirable outcomes. This study aims to assess the characteristics of the RMF and its relation to the occlusal plane (OP) using cone-beam computed tomography (CBCT) data. Material and Methods: This cross-sectional observational in vitro study involved the analysis of CBCT data from 136 samples (68 males and 68 females) within the age range of 18–40 years. The study focused on factors such as the presence or absence of the RMF, whether it was unilateral or bilateral, the number of foramina on each side, and the distance of the RMF from the OP. Data analysis was conducted using the Statistical Package for the Social Sciences software, with P < 0.05 deemed statistically significant at a 95% confidence level. Results: About 39% of the sample showed the presence of RMF. The prevalence of unilateral RMF was higher than that of bilateral RMF. The mean distance of RMF above the OP was 5.99 mm, and that below the OP was 3.82 mm. Conclusion: The high prevalence (39%) of RMF suggests that the retromolar fossa region should be evaluated before the placement of mini-plates. The prevalence of RMF above the OP was significantly higher than that below the OP.

Evaluation of the anterior processes of the parotid gland: an ultrasonographic study.

This study aimed to determine the prevalence of anterior extensions of the parotid gland (AEPG), namely the accessory parotid gland (APG) and the facial process of the parotid gland (FP), using ultrasonography. A total of 338 parotid glands were scanned bilaterally. APG was defined as a soft tissue mass with the same echogenic features as the main parotid gland (MPG) and not in contact with it, while FP was defined as an extension that exceeded the anterior border of the mandibular ramus and was continuous with the MPG. The anteroposterior, mediolateral, superoinferior dimensions and the mean distance from the MPG to the APG were measured. The prevalence of APG and FP were 19.5% and 36%, respectively, resulting in an AEPG prevalence of 55.6%. The presence of APG was statistically higher in females than in males (p = 0.039). The mean anteroposterior, mediolateral, and superoinferior dimensions of the APG were 18.1 ± 0.57mm, 0.35 ± 0.17mm, and 12.3 ± 0.36mm, respectively, and the mean distance from the MPG was measured as 12.1 ± 0.87mm. This study can raise awareness among clinicians about the presence of AEPG in the differential diagnosis of mid-cheek masses.

The precision of drill calibration for dynamic navigation

ObjectivesTo quantify the reproducibility of the drill calibration process in dynamic navigation guided placement of dental implants and to identify the human factors that could affect the precision of this process in order to improve the overall implant placement accuracy. MethodsA set of six drills and four implants were calibrated by three operators following the standard calibration process of NaviDent® (ClaroNav Inc.). The reproducibility of the position of each tip of a drill or implant was calculated in relation to the pre-planned implants’ entry and apex positions. Intra- and inter-operator reliabilities were reported. The effects of the drill length and shape on the reproducibility of the calibration process were also investigated. The outcome measures for reproducibility were expressed in terms of variability range, average and maximum deviations from the mean distance. ResultsA satisfactory inter-rater reproducibility was noted. The precision of the calibration of the tip position in terms of variability range was between 0.3 and 3.7 mm. We noted a tendency towards a higher precision of the calibration process with longer drills. More calibration errors were observed when calibrating long zygomatic implants with non-locking adapters than with pointed drills. Flexible long-pointed drills had low calibration precision that was comparable to the non-flexible short-pointed drills. ConclusionThe clinicians should be aware of the calibration error associated with the dynamic navigation placement of dental and zygomatic implants. This should be taken in consideration especially for long implants, short drills, and long drills that have some degree of flexibility. Clinical significanceDynamic navigation procedures are associated with an inherent drill calibration error. The manual stability during the calibration process is crucial in minimising this error. In addition, the clinician must never ignore the prescribed accuracy checking procedures after each calibration process.

Prospective Evaluation of Results of Surgical Treatment of Patients with Idiopathic Macular Hole by Phacovitrectomy and Combined Cataract and Vitrectomy Surgery

Purpose of the study:The purpose of the study was to compare the morphological and functional results of the studied patients with idiopathic macular hole treated with a one-stage method (phacovitrectomy) and combined cataract and vitrectomy surgery.Material and methods:The study included 33 patients (33 eyes) with idiopathic macular hole treated at the Department of Retina and Vitreous Surgery in Lublin. Twenty-one eyes were surgically treated with phacovitrectomy (Group 1 MH). Twelve patients underwent two-stage, combined treatment with removal of the lens in the first stage and vitrectomy in the second (Group 2 MH). The assignment of patients to groups was random. All patients underwent 23-gauge sutureless vitrectomy with removal of the internal limiting membrane (internal limiting membrane peeling). SF6 gas was used as an intraocular tamponade at an isovolumetric concentration of 20% and face down position recommendation for 7 days. Cataract surgery was performed using the phacoemulsification method with an incision in the transparent part of the cornea with intracapsular, posterior chamber implantation of a monofocal lens. A 12-month observation period was established, measured from the date of vitrectomy performance, and in the case of a combined procedure, this period was extended by the time between each stage of treatment. At subsequent check-ups, the subjects underwent a complete ophthalmological examination, which included: best corrected distance visual acuity and best corrected near visual acuity, assessment of the anterior and posterior segments, in a slit lamp, measurement of retinal sensitivity in the macula using microperimetry, the Amsler test and optical coherence tomography examination of the macula.Results:In patients of the total studied group, an improvement in the best-corrected visual distance and near acuity was obtained, and in 88% retinal sensitivity in the macula was also achieved. In the group of patients subjected to phacovitrectomy (Group 1 macular hole) with an average minimum hole diameter of 487.48 µm before the procedure, after a one-year follow-up the mean best corrected distance visual acuity was 0.57 and best corrected near visual acuity 0.51, with macular retinal sensitivity of 26.65 dB. However, in the group of patients subjected to combined cataract and vitrectomy, an average minimum hole diameter of 521.58 µm 12 months after trans pars plana vitrectomy was performed as well as an average best corrected distance visual acuity of 0.64, best corrected near visual acuity of 0.5, and retinal sensitivity in the macula of 25.98 dB. There were no statistically significant differences between phacovitrectomy and the combined procedures in terms of the improvement in the values of distance and near visual acuity and macular retinal sensitivity 12 months after trans pars plana vitrectomy. A statistically significant improvement in retinal sensitivity in the macula was observed in Group 1 macular hole during the 12-month follow-up, while in the combined procedure group the improvement was not statistically significant.Conclusions:Vitrectomy is an effective method of treating maculopathy in the form of macular hole. Morphological and functional improvement was noted in all patients, regardless of the treatment method used. There were no statistically significant differences between phacovitrectomy and the combined procedure in terms of the improvement achieved in the values of distance visual acuity parameters, near vision and retinal sensitivity in the macula 12 months after trans pars plana vitrectomy. A common feature of patients with worse results on individual variables was a longer duration of the disease and a larger size of the hole prior vitrectomy.

Abstract PO1-09-07: Outpatient mastectomy is a safe surgical option for patients treated in a rural Appalachian tertiary facility

Abstract Background The feasibility of the outpatient mastectomy in a rural setting is poorly characterized. Centers treating rural patient populations have unique challenges. Limited access to resources and distance to facilities that can care for post-surgical patients are two such challenges. The aim of this study is to analyze the efficacy and safety of an outpatient mastectomy program in our tertiary care facility treating rural Appalachian patients. Methods We performed a single-institution retrospective review of all patients with breast cancer over 18 years of age who underwent a mastectomy with or without immediate alloplastic breast reconstruction at JW Ruby Memorial Hospital from 2019-2022. Our primary objective was to determine the 30, 60, and 90-day readmission rates. Our secondary objective included an analysis of perioperative pain control variables to develop an enhanced recovery protocol. Data collected included age, ethnicity, prognostic factors, stage at diagnosis, surgical treatment, opioid and non-opioid based treatments pre- and postoperatively by milligram morphine equivalents (MMEs), comorbidities as analyzed by the Charlson comorbidity index (CCI) variables, and distance from the tertiary hospital. Results We identified thirty-two women between 2019-2022 who underwent same-day mastectomy at JW Ruby Memorial Hospital in Morgantown, West Virginia. The mean age was 55.4 years. The mean distance to the hospital was 22.1 miles with a maximum distance of 111 miles (SEM = 3.90). The mean CCI score was 2.9 (SEM = 0.51). Overall readmission rates at 30- 60- and 90-days were 6.3% (n = 2), 3.1% (n = 1) and 0%, respectively. One woman was readmitted eight days postoperatively from a unilateral mastectomy and sentinel lymph node biopsy without reconstruction for an expanding hematoma of the chest after resuming anticoagulation on postoperative day three. The other two patients were admitted for unrelated surgical reasons. Thus, readmission related to surgical complications alone was 3.1% (n = 1). Preoperatively, 90.6% (n = 29) of women received a local anesthetic block by the anesthesia provider. Neither a preoperative nor intraoperative block was given to the remaining three. Bilateral mastectomies occurred in 21.9% (n = 7) of women and 78.1% (n = 25) underwent unilateral mastectomy. Of these 32 women, 25.0% (n = 8) underwent immediate staged reconstruction with tissue expanders. There were no direct-to-implant reconstructions in this population. There were twenty-six sentinel lymph node biopsies and four axillary dissections performed. The mean MMEs received for the duration of the hospital encounter was 132 (SEM = 23.4). An enhanced recovery after surgery protocol was not used. Discussion Outpatient mastectomy is a safe and effective option for eligible patients living in rural settings. Factors such as the type of mastectomy, reconstruction, the patient's overall health status, and the availability of support at home can impact the feasibility of this approach. Careful patient selection and a multidisciplinary team including the patient, surgeon, and anesthesiologist should carefully assess the individual’s circumstances to determine if outpatient mastectomy is appropriate. Implementation of enhanced recovery after surgery protocols will be further investigated and guided by this study. Citation Format: Gregory Stimac, Kristin Lupinacci, Michael Cowher, Hannah Hazard-Jenkins. Outpatient mastectomy is a safe surgical option for patients treated in a rural Appalachian tertiary facility [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 PO1-09-07.

Abstract PO2-23-04: Magnetic Seeds, used to Locate the Metastatic Axillary Lymph Node placed before Neoadjuvant Chemotherapy for Breast Cancer Treatment, do not interfere the pre-surgical MRI Breast response assessment

Abstract Background: Axillary management in clinically node-positive patients who converted to ycN0 after neoadjuvant chemotherapy (NAC) for breast cancer (BC) remains under research with the aim of de-escalation of axillary lymph node dissection (ALND). A magnetic seed is one of the several positive lymph nodes marking techniques used in targeted axillary dissection (TAD) for patients with cN1 breast cancer undergoing neoadjuvant systemic therapy. It has been criticized for its potential masking effect due to the artefact it produces in the MRI sequences used to assess a proper breast response. This study evaluates if the magnetic seeds placed before NAC for guided TAD have influenced in the breast MRI response assessments. Methods: From October 2021 to June 2023, patients with cT0-4 cN1 breast cancer who were candidates for primary systemic treatment were prospectively recruited. Once a breast lesion and axillary node positivity were confirmed, a based hydrogel marker and a magnetic seed, respectively, were placed prior NAC. Once systemic treatment was completed, imaging techniques were used to assess the response, with MRI being the imaging technique of choice to assess breast response and axillary ultrasound the imaging technique of choice to assess axillary response. Surgical pathological confirmation of response in the axilla was by TAD, including sentinel lymph node and magnetic clipped node resection. Results: A total of 43 patients were included and their characteristics are shown in Table 1. In 16 patients (37%) the tumour was located in the upper outer quadrant (UOQ). In this group, the susceptibility artefact produced by the magnetic seed in the MRI created a black hole obscuring the axilla with a mean diameter of 69 mm (range: 57-76 mm). In no case did the halo interfere with the correct MRI visualisation of the breast marker. By MRI, the mean distance of the artifact halo from the breast marker or residual breast lesion was 40 mm (range: 13-79 mm). Overall, complete radiological response (ycCR) was reported in 20 patients (46%), breast only in 21 (49%) and axilla only in 38 (88%) patients. In 5 patients, preoperative axillary ultrasound revealed residual axillary disease, confirmed by FNA, lead to direct ALND. In the remaining 38 patients the axillary TAD assessment was completed. In all cases, the magnetic clipped node was successfully surgically removed. Pathological complete response (pCR) was confirmed in 9 (21%), breast only in 11 (26%) and axilla only in 13 (30%) patients. MRI diagnostic performance in detecting residual breast disease after NAC was not altered by the magnetic clipped node artifact when comparing the tumour location in the UOQ to the other quadrants (AUC 0.764 vs. 0.702; p=0.698). Conclusions: Surgical axillary staging remains the most reliable method for assessing the axillary response after NAC. Target axillary dissection guided by magnetic seed placed before NAC is an effective and accurate technique. The artifact generated in the MRI does not interfere with the pre-surgical breast response assessment after neoadjuvant systemic treatment. Table 1: Patients and tumor characteristics Citation Format: Martin Espinosa-Bravo, Joaquin Rivero Deniz, Clara Morales Comas, Javier de la Torre Fernandez de Vega, Irene Vives Rosello, Enrica Esposito, Vicente Peg Camara, María De Les Neus Rus Calafell, Ignacio Miranda Gomez, Christian Siso Raber. Magnetic Seeds, used to Locate the Metastatic Axillary Lymph Node placed before Neoadjuvant Chemotherapy for Breast Cancer Treatment, do not interfere the pre-surgical MRI Breast response assessment [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 PO2-23-04.

Transpalpebral transorbital endoscopic lateral approach to the middle cranial fossa: anatomical study in cadaver

Transorbital expanded endoscopic approaches allow different areas of the skull base to be approached. The aim of our study is to analyse the main anatomical bone and neurovascular structures of the middle cranial fossa by means of a transpalpebral transorbital lateral endoscopic approach (TTLEA). An anatomical study was performed on 12 orbital cavities corresponding to 6 cadaver heads. All specimens were previously injected with colored latex through both carotid systems. The mean distance from the orbital rim to the zygomatic-facial foramen and to the zygomatic-temporal foramen was 11 mm and 16 mm respectively. In all cases the meningo-orbital foramen was found at a mean distance from the orbital rim of 34 mm. The superior orbital fissure (SOF) was located posterior to the meningo-orbital foramen at 39 mm. The foramen rotundum and foramen ovale were located separated from each other by 10 mm on average. Anterior to the foramen ovale a bony prominence was observed in all cases. In 11 cases (92%) the entrance of the accessory meningeal artery into the foramen ovale was evident and in one case an accessory foramen was observed. The middle meningeal artery was located in all dissections within the foramen spinosum. The TTLEA offers a wide and direct exposure of the middle cranial fossa. It should be considered as an alternative to transcranial approaches in certain lesions invading the lateral region of the middle cranial fossa, the lateral wall of the cavernous sinus or the infratemporal fossa.

Effect of retarded friction and added mass on the swimming speed of a vibrating two-sphere

A theoretical expression is derived for the mechanical contribution to the mean swimming speed of a vibrating two-sphere, consisting of two spheres connected by an elastic spring, and immersed in a viscous incompressible fluid. The spring provides a harmonic potential for oscillations about a mean distance between centers. The system is made to oscillate at a chosen frequency by activating forces which sum to zero. The mechanical contribution to the resulting mean swimming velocity is calculated from the mechanical equations of motion and the corresponding impedance matrix of linear response. The frequency-dependent pair friction coefficients are found from approximate expressions derived earlier. The mechanical contribution is calculated to second order in the amplitude of stroke as a function of the scaling number, a dimensionless combination of size, frequency, and kinematic viscosity. Retarded friction and added mass determine the functional behavior.

Inter-fractional error and intra-fractional motion of prostate and dosimetry comparisons of patient position registrations with versus without fiducial markers during treatment with carbon-ion radiotherapy.

A few reports have discussed the influence of inter-fractional position error and intra-fractional motion on dose distribution, particularly regarding a spread-out Bragg peak. We investigated inter-fractional and intra-fractional prostate position error by monitoring fiducial marker positions. In 2020, data from 15 patients with prostate cancer who received carbon-ion beam radiotherapy (CIRT) with gold markers were investigated. We checked marker positions before and during irradiation to calculate the inter-fractional positioning and intra-fractional movement and evaluated the CIRT dose distribution by adjusting the planning beam isocenter and clinical target volume (CTV) position. We compared the CTV dose coverages (CTV receiving 95% [V95%] or 98% [V98%] of the prescribed dose) between skeletal and fiducial matching irradiation on the treatment planning system. For inter-fractional error, the mean distance between the marker position in the planning images and that in a patient starting irradiation with skeletal matching was 1.49 ± 1.11mm (95th percentile = 1.85mm). The 95th percentile (maximum) values of the intra-fractional movement were 0.79mm (2.31mm), 1.17mm (2.48mm), 1.88mm (4.01mm), 1.23mm (3.00mm), and 2.09mm (8.46mm) along the lateral, inferior, superior, dorsal, and ventral axes, respectively. The mean V95% and V98% were 98.2% and 96.2% for the skeletal matching plan and 99.5% and 96.8% for the fiducial matching plan, respectively. Fiducial matching irradiation improved the CTV dose coverage compared with skeletal matching irradiation for CIRT for prostate cancer.

Trend change analysis in the assessment of body balance during posture adjustment in reaction to anterior-posterior ground perturbation.

Postural adjustments (PA) occur to counteract predictable perturbations and can be impaired as a result of musculoskeletal and neurological dysfunctions. The most common way to detect PA is through electromyography measurements or center of pressure (COP) position measurements, where analysis in time domain and frequency domain are the most common. Aim of the research was to determine whether a new method of analyzing stabilographic measurements-the COP trend change analysis (TCI) of temporary posture corrections- can expand understanding of changes in balance strategy connected with PA. The study group involved 38 individuals (27women, 11men) aged 23±2.6 years. Measurements were performed using a stabilographic platform placed on a perturbation platform. The tests involved three measurements with forward and backward momentary movements of the platform. Participants were tested in three conditions-knowing the nature, time and direction of perturbation (Tr3), knowing only the nature of perturbation (Tr2) and without any information about the perturbation (Tr1). Statistically significant differences were revealed in the last second of Tr3 for the mean velocity of COP (p<0.05) and for two TCI parameters-TCI_dV (p<0.05) and TCI_dS (p<0.01). The increase in TCI_dV was related to the increase in the mean distance between trend changes (TCI_dS) and constant value of the mean time between trend changes (TCI_dT). The increase of the mean value of TCI_dS was the result of smaller number of posture corrections with the distance 0-2 mm and lager number with the distance 4-6 mm. Obtained results proved that the TCI analysis is a method enabling an extended analysis of PA, indicating the nature of changes occurring in posture corrections-longer momentary jumps of COP-related to a change in the strategy of maintaining balance before a known disorder, which has not been analyzed in this type of research so far.

Study of the irradiation hardening of a Fe9Cr ferritic model alloy by nanoindentations

This paper presents a series of Berkovich indentation results obtained on unirradiated and 7.2 MeV proton irradiated specimens of a Fe9Cr model alloy with an equiaxed ferritic microstructure. Using a energy degrader wheel made of 24 aluminum foils of different thickness, a flat damage profile of about 50 μm resulted from the irradiation, allowing to perform indentations within a volume material that is homogeneously irradiated. The indentation size effect on measured hardness was analyzed with a model based on the disloction-slip distance theory built on the concept of combined spatial frequency of all obstacles to dislocation motion. The effects on hardness of the tip-specimen contact size (or penetration depth), dislocation density and mean distance between irradiation defects were quantified and discussed. The irradiation hardening was characterized by the increase of hardness determined at large penetration depths.

Distribution Pattern of Species Richness of Endemic Genera in Mountainous Areas of Southwest China and Its Influencing Factors

China’s southwest mountainous region is one of the hotspots of biodiversity in the world. However, the study on the pattern of species richness distribution of endemic plants in this region and its influencing factors is still in the exploration stage. A clear regional spatial distribution pattern of plants and its influencing factors are very important for the protection and management of plant diversity in southwest China. In this study, 511 county-level regions in the southwest mountainous region were taken as examples to establish a plant species resource bank in the southwest mountainous region, and the distribution pattern of the proportion and abundance of endemic plant families and genera was analyzed based on 19 climate and environmental factors and 8 human disturbance factors in the southwest mountainous region. The geographical weighted regression model (GWR) was used to reveal the main factors affecting the spatial distribution of species. The results showed that: (1) A total of 4688 species investigated in the southwest mountain belong to 19 families and 32 genera. (2) The endemic species richness in the southwest mountainous region showed a significant uneven spatial pattern, mainly concentrated in the Heng Duan Mountain area, southwest Sichuan and northern Yunnan area, and the Ruoergai-Hongyuan area of West Sichuan Plateau. (3) The results of the GWR model showed that the diurnal mean temperature range, precipitation seasonality and distance from the main road had significant effects on species richness. The study on the distribution of endemic genera and their influencing factors in the southwest mountainous region has important implications for the exploration of the evolutionary history and species conservation of the mountain flora.

Delineating the evolutionary pathway to multidrug-resistant outbreaks of a Mycobacterium tuberculosis L4.1.2.1/Haarlem sublineage

ObjectivesWe sought to capture the evolutionary itinerary of the Mycobacterium tuberculosis L4.1.2.1/Haarlem sublineage in northern Tunisia, where it caused a major multidrug-resistant (MDR) tuberculosis outbreak in a context strictly negative for HIV infection. MethodsWe combined whole genome sequencing and Bayesian approaches using a representative collection of drug-susceptible and drug-resistant L4.1.2.1/Haarlem clinical strains (n = 121) recovered from the outbreak region over 16 years. ResultsIn the absence of drug resistance, the L4.1.2.1/Haarlem sublineage showed a propensity for rapid transmission as witnessed by the high clustering (44.6%) and recent transmission rates (25%), as well as the reduced mean distance between genome pairs. The entire pool of L4.1.2.1/Haarlem MDR strains was found to be linked to either the aforementioned major outbreak (68 individuals, 2001-2016) or to a minor, newly uncovered outbreak (six cases, 2001-2011). Strikingly, the two outbreaks descended independently from a common ancestor that can be dated back to 1886. ConclusionsOur data point to the intrinsic propensity for rapid transmission of the M. tuberculosis L4.1.2.1/Haarlem sublineage in northern Tunisia, linking the overall MDR tuberculosis epidemic to a single ancestor. These findings bring out the important role of the bacillus’ genetic background in the emergence of successful MDR M. tuberculosis clones.