Increasing contrast in water-embedded particles via time-gated mid-infrared photothermal microscopy.

The transient dynamics of photothermal signals provide interesting insights into material properties and heat diffusion. In a mid-infrared (mid-IR) photothermal microscope, the imaging contrast in a standard amplitude imaging can decrease due to thermal diffusion effects. It is shown that contrast varies for poly-methyl 2-methylpropenoate (PMMA) particles of different sizes when embedded in an absorbing medium of water (H2O) based on levels of heat exchange under the water absorption resonance. Using time-resolved boxcar (BC) detection, analysis of the transient thermal dynamics at the bead-water interface is presented, and the time decay parameters for 500 nm and 100 nm beads are determined. Enhanced (negative) imaging contrast is observed for less heat exchange between the water and bead, as in the case for the 100 nm bead. For the 500 nm bead, boxcar imaging before heat exchange starts occurring, leads to an increase of the imaging contrast up to a factor of 1.6.

Morphology and Prevalence of the Inferior Transverse Scapular Ligament: Systematic Review, Meta-Analysis, and Proposal for Classification.

Background/Objectives: The suprascapular nerve is most vulnerable to entrapment at the suprascapular and spinoglenoid notches, causing neuropathy. Numerous studies have examined the suprascapular notch and ligament and its relationship with suprascapular nerve entrapment, but few have examined the spinoglenoid notch and the inferior transverse scapular ligament (ITSL). This study summarizes all existing ITSL morphology studies and presents a simple and comprehensive classification system for different ITSL subtypes. Methods: A systematic review of the literature was conducted according to the PRISMA guidelines, searching the online databases PubMed and Embase. The references of each relevant article were further screened to find more eligible studies. The Anatomical Quality Assessment tool was used in order to further evaluate the quality of the records extracted. STATA MP 14 was used for the analysis in this study. Results: In total, 14 studies (995 scapulae; minimum: 1 and maximum: 268) were included in the present study. The overall ITSL prevalence was 5.8 (95% CI: 4.5-7.1) and the estimated odds for ligamentous vs. membranous type was 0.5 (95% CI: 0.3-0.7). The basic different morphological subtypes of the ITSL reported in the included studies are the band-like ligament, the fan-shaped ligament, the membranous ITSL, and the perforated membranous types. Conclusions: The ITSL represents an anatomical structure of mostly ligamentous nature. A single ITSL definition and standardization of its basic morphological subtypes along with an easy-to-remember and thus widely used classification system could greatly facilitate the comprehensive description, identification, and proper handling of this element across many surgical procedures.

Time-Resolved Mid-Infrared Photothermal Microscopy for Imaging Water-Embedded Axon Bundles.

Few experimental tools exist for performing label-free imaging of biological samples in a water-rich environment due to the high infrared absorption of water, overlapping with major protein and lipid bands. A novel imaging modality based on time-resolved mid-infrared photothermal microscopy is introduced and applied to imaging axon bundles in a saline bath environment. Photothermally induced spatial gradients at the axon bundle membrane interfaces with saline and surrounding biological tissue are observed and temporally characterized by a high-speed boxcar detection system. Localized time profiles with an enhanced signal-to-noise, hyper-temporal image stacks, and two-dimensional mapping of the time decay profiles are acquired without the need for complex post image processing. Axon bundles are found to have a larger distribution of time decay profiles compared to the water background, allowing background differentiation based on these transient dynamics. The quantitative analysis of the signal evolution over time allows characterizing the level of thermal confinement at different regions. When axon bundles are surrounded by complex heterogeneous tissue, which contains smaller features, a stronger thermal confinement is observed compared to a water environment, thus shedding light on the heat transfer dynamics across aqueous biological interfaces.

Thermal transport across membranes and the Kapitza length from photothermal microscopy.

An analytical model is presented for light scattering associated with heat transport near a cell membrane that divides a complex system into two topologically distinct half-spaces. Our analysis is motivated by experiments on vibrational photothermal microscopy which have not only demonstrated remarkably high contrast and resolution, but also are capable of providing label-free local information of heat transport in complex morphologies. In the first Born approximation, the derived Green's function leads to the reconstruction of a full 3D image with photothermal contrast obtained using both amplitude and phase detection of periodic excitations. We show that important fundamental parameters including the Kapitza length and Kapitza resistance can be derived from experiments. Our goal is to spur additional experimental studies with high-frequency modulation and heterodyne detection in order to make contact with recent theoretical molecular dynamics calculations of thermal transport properties in membrane systems.

Anatomical variations of human vertebral and basilar arteries: A current review of the literature.

The vertebral artery originates from the subclavian artery and is divided into four segments (V1-V4). In its intracranial segment (V4), the two vertebral arteries join to form the basilar artery, an unpaired medium-sized artery. However, apart from this typical description, several anatomical variations may occur in the human body. Although in some cases such variations may be asymptomatic, they may be also associated with several pathological conditions, neurological complications, surgical complications, and increased risk of developing vascular diseases. Therefore, it is crucial to obtain sufficient information on the anatomy and variants of both arteries to prevent such complications and ensure the safe completion of surgical and radiological treatments. For this reason, we reviewed studies published up to January 2022 concerning the reported variations of the vertebral artery and basilar artery regarding their origin, course, length, and diameter. We believe that the thorough presentation of these variations would help surgeons worldwide during their daily clinical and surgical practice.

Using Technology to Build Trusted Relationships Between Nurses.

The future of leadership and nurse engagement requires the use of technology. The nursing workforce is becoming more mobile, flexible, and dynamic. Technology can support nurses to build trusted professional relationships and enhance their professional practice. Nursing leaders need to learn how to effectively use technology in addition to in-person interactions to support their nursing workforce. This article provides tips and tricks for nurse leaders to build relationships with their teams through technology.

Phase-sensitive lock-in detection for high-contrast mid-infrared photothermal imaging with sub-diffraction limited resolution.

Imaging of the phase output of a lock-in amplifier in mid-infrared photothermal vibrational microscopy is demonstrated for the first time in combination with nonlinear demodulation. In general, thermal blurring and heat transport phenomena contribute to the resolution and sensitivity of mid-infrared photothermal imaging. For heterogeneous samples with multiple absorbing features, if imaged in a spectral regime of comparable absorption with their embedding medium, it is demonstrated that differentiation with high contrast is achieved in complementary imaging of the phase signal obtained from a lock-in amplifier compared to standard imaging of the photothermal amplitude signal. Specifically, by investigating the relative contribution of the out-of-phase lock-in signal, information based on changes in the rate of heat transport can be extracted, and inhomogeneities in the thermal diffusion properties across the sample plane can be mapped with high sensitivity and sub-diffraction limited resolution. Under these imaging conditions, wavenumber regimes can be identified in which the thermal diffusion contributions are minimized and an enhancement of the spatial resolution beyond the diffraction limited spot size of the probe beam in the corresponding phase images is achieved. By combining relative diffusive phase imaging with nonlinear demodulation at the second harmonic, it is demonstrated that 1-µm-size melamine beads embedded in a thin layer of 4-octyl-4'-cyanobiphenyl (8CB) liquid crystal can be detected with a 1.3-µm spatial full-width at half-maximum (FWHM) resolution. Thus, imaging with a resolving power that exceeds the probe diffraction limited spot size by a factor of 2.5 is presented, which paves the route towards super-resolution, label-free imaging in the mid-infrared.

Unevenly spaced continuous measurement approach for dual rotating-retarder Mueller matrix ellipsometry.

In order to efficiently extract the sample Mueller matrix by dual rotating-retarder ellipsometry, it is critical for the data reduction technique to achieve a minimal data processing burden while considering the ease of retarder control. In this paper, we propose an unevenly spaced sampling strategy to reach a globally optimal measurement matrix with minimum sampling points for continuous measurements. Taking into account the robustness to both systematic errors and detection noise, we develop multi-objective optimization models to identify the optimal unevenly spaced sampling points. A combined global search algorithm based on the multi-objective genetic algorithm is subsequently designed to solve our model. Finally, simulations and experiments are conducted to validate our approach as well as to provide near-optimal schemes for different design scenarios. The results demonstrate that significant improvement on error immunity performance can be achieved by applying an unevenly sampled measurement strategy compared to an evenly sampled one for our ellipsometer scenario.

Atlas posterior arch and vertebral artery's groove variants: a classification, morphometric study, clinical and surgical implications.

BACKGROUND: The third part of the vertebral artery (VA) coursing in vertebral artery groove (VAG) may be injured during posterior craniocervical junction approaches. OBJECTIVE: The current study classifies all possible variants of the posterior arch (PA) of the atlas vertebra (C1), focusing on VAG and calculates their incidence. PA and VAG morphometry is studied in correlation with gender and age. Clinical and surgical implications of recorded variants are provided in an effort to explain associated pathology. The usefulness of three-dimensional computed tomography (3D-CT) in detecting PA variants is highlighted. MATERIALS AND METHODS: Two hundred and forty-four Greek adult dry C1 were classified in types according to PA morphology [i.e. presence of an imprint or a distinct VAG and occurrence of a partially or completely ossified dorsal (PDP or CDP) or lateral (PLP or CLP) ponticle unilaterally or bilaterally]. Combined variants were also included. RESULTS: A VAG and an imprint were detected in 42.62% and 15.16%. A PDP and CDP were observed in 18.03% and 15.98%, while a CLP and PLP in 2.05% and 1.64%, respectively. Combined PDP and PLP were detected in 2.05%, a CDP and CLP similarly to a CDP and PLP in 1.23% and a PDP and CLP in 0.40%. CONCLUSIONS: Variants' classification will contribute to an in depth understanding of the complex C1 anatomy and may explain cases of VA entrapment and injury during PA fixation. Surgeons should carefully study 3D-CT imaging to ensure type, location, size and shape of C1 ponticles in combination with VAG morphology and VA course before screw insertion.

Acinar cell pancreatic carcinoma: a rare case of pancreatic tumor and short review of literature.

Pancreatic acinar cell carcinoma (PACC) is a rare subgenre of pancreatic adenocarcinoma, where the cells show acinar architecture. Specified causes of this neoplasia have not yet been deduced and it usually appears with nonspecific symptoms. Diagnosis is based on its characteristics in various imaging techniques, on its histological characteristics and the expression of specific immunohistochemical biomarkers. Surgical excision of the tumor is usually performed with high chances of recurrence, whereas the benefits of radiotherapy and chemotherapy are still ambiguous. In this paper, a 51-year-old female patient with a mass in the head of the pancreas was taken as a case study. She presented with icterus and imaging showed a defined mass in the head of the pancreas accompanied by dilation of the biliary tree. Biopsy and histological assessment done after the surgical excision showed components of PACC differentiation. The patient was regulated after surgery, especially regarding endocrinology and immunology.

Quadrifurcation of the Facial Artery Near the Inferior Mandibular Border with a Bilateral Premasseteric Artery Component.

During the dissection of the cervicofacial area in a donated male cadaver, an asymmetrical division of the facial artery (FA) and a premasseteric artery (PA) were identified. Specifically, on the left side, the FA stem is divided into four branches (quadrifurcation) 4.26 mm below the lower border of the mandible. In contrast, it is divided into two branches (bifurcation) on the right side. Whether symmetrical or asymmetrical, these variants can have significant implications for rhinoplastic, maxillofacial, or reconstructive surgery. This finding underscores the crucial role of surgeons in exercising caution and paying close attention during these procedures to avoid potential damage.

Anatomy of the lymphatics in normal stomach and gastric carcinomas.

The lymphatic system is composed of lymphoid organs/tissues and a complex network of lymphatic vessels that transport interstitial fluid, antigens, lipids, immune cells, and other materials in the body. There is growing evidence that lymphatic vasculature is associated with many pathological conditions such as lymphedema and cancer progression and metastasis. Thus, improved understanding of the anatomical features, the molecular profile and the function of the lymphatic vasculature may provide innovative approaches for disease prevention and treatment. This article aims to present a comprehensive review of the gastric lymphatic anatomy and its importance in the pathology, treatment and prognosis of gastric carcinomas.

Entrapment of the Subscapular Artery between the Radial Nerve and the Posterior Wall of the Axilla: An Anatomical Variation with Clinical Significance.

OBJECTIVE: The subscapular artery vascularizes a substantial region of the thoracic wall, and the significance of its distribution is well depicted in the diversity of reconstructive procedures that rely on its blood supply. The aim of this study is to present an uncommon anatomical variation of the artery and discuss the clinical implications of its presence. CASE REPORT: This case report depicts a rare variant of compression and the kinking of the subscapular artery by the radial nerve on the posterior wall of the axilla that was encountered during dissection of a male cadaver of Greek origin. CONCLUSION: The use of autologous tissues in the reconstruction of defects and treatment of lymphedema is expanding, so the need to establish safer surgical dissections is also becoming more apparent. The case of entrapment of the subscapular artery by the radial nerve is extremely rare, however, utilizing tissues perfused by this artery for reconstructive purposes could potentially be futile and unsuccessful due to the inadequate blood supply or vessel thrombosis. Hence, the surgeon should adapt the treatment plan according to preoperative findings, as the presence of anatomical variants should always be suspected.

An Ectopic External Jugular Vein Draining into the Axillary Vein: a Rare Anatomical Variation with Clinical Implications.

OBJECTIVE: The external jugular vein drains a considerable part of the head and neck and constitutes a vessel implicated in various procedures in the cervical region. The aim of this study is to present an uncommon anatomical variation of the external jugular vein, and discuss the clinical implications of its presence. CASE REPORT: We present a rare case of an ectopic external jugular vein terminating into the axillary vein, that we came across during routine dissection of a male cadaver of Greek origin. CONCLUSION: The venous system of the external jugular vein is used during procedures for the treatment of various conditions such as cardiac arrhythmias, hydrocephalus and defects of the head and neck. Hence, encountering the unpredictable course of a variant draining into the axillary vein may complicate these interventions, leading to multiple manipulations and undesirable results. Surgeons should be aware of the alternate anatomy of the venous system of the cervical region, and mindful of the possibility of encountering them.

Repeated sprint ability in young football players according to the position and formation of the team: the effect of a specific training program.

BACKGROUND: The aim of this study was to investigate the effect of a specific training program for 12-weeks (twice a week) on the repeated sprint ability (RSA), according to the position of the football player in the formation of the team. METHODS: Two groups of U-17 football players (experimental-group, N.=22 and control-group, N.=19) and five positions (central-defenders, wide-defenders, central-midfielders, wingers, and central-attackers) according to the position in the formation (1-4-3-3) were studied. Sexual maturation was classified according to Tanner's stages. RSA and isokinetic strength were measured pre- and after the training program. RESULTS: The results showed that in RSA were differences in the factor time in the best (F=9.316, η2=0.383, P=0.008) and mean time (F=8.002, η2=0.348, P=0.013), but there were no differences between the groups. In strength, differences were observed in the time, mostly in the extensors at the three angular velocities (60°, 180°, 300°·sec-1) with differences in the group only in the maximum force (F=8.090, η2=0.366, P=0.013). No differences between players' positions were observed. CONCLUSIONS: A specific training program seems to affect players' performance on repeated sprint ability and the specific training in the players' position according to the team formation has a positive effect on the muscle power of football players.

The Coronoid Anatomical Variation of the Masseter Muscle: A Case Report.

INTRODUCTION: Masseter muscle is considered to consist of two layers: the superficial and the deep parts. However, in the literature a few cases have been reported of a third layer of the masseter muscle, which is called the coronoid part. The aim of this study is to present such a rare case of the coronoid part of the masseter muscle. MATERIAL AND METHODS: In our study, a case report is presented and enhanced by searching the existing literature in PubMed for other similar cases that recorded the coronoid part of the masseter muscle. RESULTS: The coronoid part of the masseter muscle was found in a male cadaver of Greek origin that was dissected in the Department of Anatomy, Medical School Athens, Greece. CONCLUSIONS: Good knowledge of anatomy and variations of the masseter muscle are of paramount importance due to their clinical and functional applications as well as during surgical procedures in this anatomical region.

A Review of the Typical Course of the Musculocutaneous Nerve into the Coracobrachialis Muscle: Its Variability and Possible Clinical Implications.

OBJECTIVE: This literature review highlights the prevalence of the typical course of the musculocutaneous nerve (MCN) through the coracobrachialis muscle (CB), and evaluates the distance from the entrance point of the MCN to the CB, taking the coracoid process (CP) as a landmark. METHODS: PubMed (MEDLINE), Scopus, and CINAHL online databases were searched in December 2022 for studies reporting the prevalence of the MCN's typical course and the distance between the CP and the MCN entrance point to the CB. RESULTS: Twenty-eight studies were included (including 2846 subjects) investigating the MCN's typical course, and eliciting a prevalence of 93.4%. The mean distance of the CP to the entrance point of the MCN's main trunk into the CB was 5.6±2cm (median 6.1cm, in 550 subjects). In 76.12% of cases the MCN's accessory branches entered the CB proximally to the MCN's main trunk. The mean distance from the CP to the entrance point of the MCN's proximal branches to the CB was 3.8±1.2cm (median 3.7cm, in 140 subjects). CONLCUSION: In the vast majority of cases, the MCN had a typical course through the CB. In cases of altered anatomy, the MCN was either absent or passed medially to the CB (without piercing it). The average entrance point of the MCN into the CB from the CP is 5.6 cm. Proximal motor branches of the MCN to the CB are common and usually arise at a mean distance of 3.8cm from the inferior border of the tip of the CP. Surgeons should be aware of both the MCN's typical and its atypical course and these distances to avoid possible complications when operating in the area.

Anatomical Considerations and Plastic Surgery Reconstruction Options of Sacral Chordoma Resection.

Introduction Chordomas are slow-growing malignant bone tumors arising from remnant embryonic notochord cells with predilection for the sacrum. They rarely metastasize, and early surgical resection with clear margins is the treatment of choice followed by plastic surgery reconstruction supplemented with adjuvant radiotherapy based on the local treatment protocol or in cases with a contaminated surgical field. Aim The aim of the present study is to present our experience in surgical management of sacral chordomas and propose a surgical reconstruction algorithm considering anatomical parameters after partial or total sacrectomy. Materials and methods  Twenty-seven patients with sacral chordomas were treated in our Orthopaedic Surgery Department between January 1997 and September 2022, and 10 of them had plastic surgery reconstruction. Patients were divided into groups based on the type of sacrectomy, sacrum anatomical vascular or neural variations, partial or total, and the type of soft tissue reconstruction. The postoperative complications and the functional outcomes in each patient were assessed. Results  Bilateral gluteal advancement flaps or gluteal perforator flaps are the first choice in patients with partial sacrectomy, intact gluteal vessels, and without preoperative radiotherapy followed by transpelvic vertical rectus abdominis myocutaneous flap or free flaps in those patients with near total sacrectomy and preoperative radiation therapy. Conclusion  There are four reliable options for patients after sacral chordoma resection: direct closure, bilateral gluteal advancement flaps, transpelvic vertical rectus abdominis myocutaneous flaps, and free flaps. Each time, tumor-free margins and a good reconstructive plan according to the defect and patient characteristics are mandatory.

Anatomical variations of the vascular supply of the cutaneous component of the serratus anterior myocutaneous flap: a systematic review.

Although appealing from a reconstructive standpoint, the incorporation of the overlying skin in a serratus anterior muscle flap has not yet seen widespread use, due to considerations with its blood supply. In the present study, a systematic review of the literature has been performed, evaluating studies that investigated the vascular anatomy and variations of serratus anterior myocutaneous flap. The anatomy of the cutaneous blood supply, the size of the cutaneous territory, the design of the skin paddle and the reconstructive goals were analysed. The results showed that the main blood supply originates from the intramuscular anastomoses between intercostal artery perforators and the serratus artery branch in the form of choke vessels. Complementary perfusion from true intramuscular vessel anastomoses or from direct serratus artery cutaneous perforators could contribute to the skin blood supply but only in 25% of the cases. The design of the flap is elliptical with its long axis over the harvested muscle slips and maximum width is 6-8 cm. A myocutaneous serratus anterior flap could be applied in a variety of reconstructive fields, most commonly for head and neck defects. A delay procedure would considerably enhance the perfusion of the cutaneous component and improve the overall viability of the flap.

Botulinum Toxin in the Surgical Treatment of Complex Abdominal Hernias: A Surgical Anatomy Approach, Current Evidence and Outcomes.

BACKGROUND/AIM: Abdominal wall hernias represent a common problem in surgical practice. A significant proportion of them entails large defects, often difficult to primarily close without advanced techniques. Injection of botulinum toxin preoperatively at specific points targeting lateral abdominal wall musculature has been recently introduced as an adjunct in achieving primary fascia closure rates. MATERIALS AND METHODS: A literature search was conducted investigating the role of botulinum toxin in abdominal wall reconstruction focusing on anatomic repair of hernia defects. RESULTS: Injecting botulinum toxin preoperatively achieved chemical short-term paralysis of the lateral abdominal wall muscles, enabling a tension-free closure of the midline, which according to anatomic and clinical studies should be the goal of hernia repair. No significant complications from botulinum injections for complex hernias were reported. CONCLUSION: Botulinum is a significant adjunct to complex abdominal wall reconstruction. Further studies are needed to standardize protocols and create more evidence.