Visualization of π-hole in molecules by means of Kelvin probe force microscopy.

Submolecular charge distribution significantly affects the physical-chemical properties of molecules and their mutual interaction. One example is the presence of a π-electron-deficient cavity in halogen-substituted polyaromatic hydrocarbon compounds, the so-called π-holes, the existence of which was predicted theoretically, but the direct experimental observation is still missing. Here we present the resolution of the π-hole on a single molecule using the Kelvin probe force microscopy, which supports the theoretical prediction of its existence. In addition, experimental measurements supported by theoretical calculations show the importance of π-holes in the process of adsorption of molecules on solid-state surfaces. This study expands our understanding of the π-hole systems and, at the same time, opens up possibilities for studying the influence of submolecular charge distribution on the chemical properties of molecules and their mutual interaction.

The feasibility of an online educational lifestyle program for people with multiple sclerosis: A qualitative analysis of participant semi-structured interviews.

Objective: To explore the feasibility of a randomised controlled trial of a multiple sclerosis online course (MSOC) via qualitative analysis of participant semi-structured interviews. Methods: The MSOC was developed in two arms: intervention arm which contained evidence-based lifestyle modification recommendations, and standard-care arm which delivered information from MS websites reflecting standard advice. Participants were recruited via online advertisements, completed a baseline questionnaire, and randomised. Seven modules were delivered over six weeks. Course completers were invited to participate in semi-structured interviews. Within a qualitative paradigm, interviews were analysed using reflexive thematic analysis. Results: Fourteen of the 17 course completers were interviewed: 86% (12/14) female; mean age 50 years; residing in Australia, New Zealand, and the USA, predominantly had relapsing-remitting MS, mean time from diagnosis 9.5 years, and patient-determined disease steps disability assessment distributed evenly across all three categories. Four themes were identified: 1) "Hearing our stories" (hope for the future, feeling represented, exploring the journey of others with MS, learning from diversity, and wanting to connect with others); 2) "Taking the plunge" (not wanting to be first, feelings of nervousness or reluctance and feeling confronted); 3) "The accessibility and safety of being online" (ease of access, going at your own pace, making it work and not letting others down); and 4) "unpacking the course" (ease of navigation, visuals, understandability, and length and timing). Conclusion: Participants felt represented, found the course accessible and content was easy to understand. These experiences provide important insights and considerations for this digital health intervention.

Latex and silicone drains in surgery − is the ban on rubber drains really a step forward or rather a step back?

The use of silicone and latex drains is an integral part of surgical practice. Experience and the review of the world literature show that silicone drain is characterized by a much lower rate of fibrotic reaction of the tissue around the drain. The ability of a latex, or rubber, or popularly called rubber drain, to induce the formation of ligaments in its surroundings is advantageously used in situations where the targeted formation of scar tissue is desired. This feature is absent in silicone drains. However, nowadays the rule in most surgical departments is to use almost exclusively silicone drains, which is based on prevention of latex allergy. This article is devoted to the description of the different and mutually irreplaceable use of silicone and latex drains. Subsequently, he also discusses the question of whether the twilight of the use of latex drains in modern medicine is really progress, or rather retrogression.

Real-space imaging of anisotropic charge of σ-hole by means of Kelvin probe force microscopy.

An anisotropic charge distribution on individual atoms, such as σ-holes, may strongly affect the material and structural properties of systems. However, the spatial resolution of such anisotropic charge distributions on an atom represents a long-standing experimental challenge. In particular, the existence of the σ-hole on halogen atoms has been demonstrated only indirectly through the determination of the crystal structures of organic molecules containing halogens or with theoretical calculations, consequently calling for its direct experimental visualization. We show that Kelvin probe force microscopy with a properly functionalized probe can image the anisotropic charge of the σ-hole and the quadrupolar charge of a carbon monoxide molecule. This opens a new way to characterize biological and chemical systems in which anisotropic atomic charges play a decisive role.

Granulomatous mastitis treatment options and our experience.

Granulomatous mastitis (GM) is a rare benign inflammatory disease of the breast, first described by Kessler and Wolloch in 1972. Clinically, it can present as unilateral, sometimes painful, increasing breast resistance, or as a hard, irregular mass. Sonography is the most useful diagnostic method for GM evaluation. The only method for definitive diagnosis is the use of biopsy. In histological findings, GM is characterized by non-caseifying granulomas, often associated with microabscess and fistula formation. There is considerable heterogeneity in treatment options; this may explain the high recurrence rate which is close to 50%. Such a high recurrence rate is alarming and proves that current treatments are suboptimal. Two treatment options are discussed worldwide: conservative strategies involving drug therapy with corticosteroids versus a surgical approach involving partial or total mastectomy. All conservative treatment options are associated with a high risk of recurrence, and most patients require surgery in the end. Thorough excision of inflammatory tissue is crucial for successful treatment while negative surgical margins are associated with a low recurrence rate. The surgical approach to GM requires sufficient radicality and presumes knowledge in the field of reconstructive breast surgery, similarly to oncosurgical breast conservation operations. However, alternatives to GM treatment with oral steroids may be acceptable for patients concerned about surgery. This article presents six case reports of patients treated at our department.

Sebaceous carcinoma of the breast area a case report.

INTRODUCTION: Sebaceous carcinoma is a rare malignant tumor of the sebaceous glands. Sebaceous carcinoma occurs mainly in the head and neck region, rarely in trunk.  Case report: We present a case report of 63-year-old patient, operated on for sebaceous carcinoma in the right breast area. The patient underwent radical surgery, removal of the tumor with the skin, subcutaneous tissue, and the large pectoral muscle. The patient is in good clinical condition eight months after the surgery. She is being constantly monitored and so far, there are neither signs of local recurrence nor tumor progression.  Conclusion: Patients with rare tumors should be treated comprehensively with subsequent lifelong dispensarisation in specialized centers. Multidisciplinary medical teams are able to eruditely diagnose, recognize, treat and dispense patients.

Harmonic scalpel versus traditional ligation in axillary dissection for breast cancer: a retrospective multivariate analysis.

INTRODUCTION: The aim of this pilot retrospective study is to evaluate the complication rate in patients after axillary dissection comparing preparation with harmonic scalpel vs traditional ligation technique, and to analyse risk factors for complications occurrence. METHODS: 144 patients with 148 axillary dissections operated in a single centre between January 2014 and 2019 were included into the study. Axillary dissection was performed using harmonic scalpel in 73 and absorbable ligations in 70 cases. RESULTS: Seroma formation was observed in 41 patients (56.2%) in the harmonic scalpel group and in 21 patients (30.0%) in the ligations group (p=0.003). The mean period from the surgery to drain removal was 4.0 days in the harmonic scalpel group and 3.0 days in the ligations group (p<0.001). The mean amount of the drained fluid after mastectomy was 300.9 ml in the harmonic scalpel group and 168.7 ml in the ligations group (p=0.005); after breast conserving surgery, it was 241.9 ml and 107.4 ml, respectively (p =0.023). CONCLUSION: In comparison with traditional ligations with absorbable material, axillary dissection using harmonic scalpel significantly increases the risk of postoperative seroma formation, prolongs the time from the surgery to drain removal, and increases the amount of drained fluid.

Self-reported cognitive function in a large international cohort of people with multiple sclerosis: associations with lifestyle and other factors.

BACKGROUND AND PURPOSE: We aimed to estimate the prevalence of perceived cognitive impairment (PCI) and explore its associations with lifestyle and disease characteristics in a large international cohort of people with multiple sclerosis (MS). METHODS: This study was a cross-sectional analysis. Participants rated their cognitive function over the preceding 4 weeks using four questions in a subscale within the Multiple Sclerosis Quality of Life questionnaire (MSQOL-54). These questions assessed perceived concentration, attention and memory by the patient and family/friends. Four definitions of PCI were derived, ranging from lowest to highest specificity. Associations with PCI were assessed by log-binomial regression. RESULTS: The prevalence of PCI in our sample ranged from 41.0% (95% confidence interval, 39.0-43.0) using the least-specific definition to 11.6% (95% confidence interval, 10.3-12.9) using the most specific definition. A number of factors were associated with PCI, increasing in magnitude as the definition specificity increased, including positive associations for smoking and body mass index, whereas physical activity, dietary quality and use of vitamin D/omega-3 supplements were inversely associated with PCI. CONCLUSIONS: Our study reports associations between healthy lifestyle behaviours and PCI in people with MS. Although reverse causality is a potential explanation for our findings, previous studies have shown comparable associations with healthy lifestyle and MS onset and progression. Subject to external validation, these results suggest benefits realized from a healthy lifestyle in people with MS.

[Breast angiosarcoma induced by radiotherapy - surgical treatment options and review of literature]. / Radiací indukovaný (postiradiacní) angiosarkom prsu - moznosti chirurgické lécby a prehled literatury.

INTRODUCTION: Radiation-induced angiosarcoma is a rare but very aggressive tumour. The highest risk of sarcoma development is in patients after breast-conserving surgery.Case 1: The 66 years old patient underwent radical mastectomy with axillary dissection because of ductal carcinoma with consequent radiotherapy, chemotherapy and hormonal therapy. After 6 years, high-grade angiosarcoma was diagnosed and resected with negative resection margins. Within subsequent 24 months, additional three radical re-excisions were performed because of repeated sarcoma recurrence. 29 months from the diagnosis of the first sarcoma, another radical re-excision was performed, this time with positive resection margins and with consequent disease progression. The patient died three years after the first angiosarcoma diagnosis.Case 2: The 68 years old patient underwent breast-conserving surgery with axillary dissection because of ductal carcinoma and radiotherapy. Breast colour changes were observed 6 years later; radical mastectomy was performed after additional 16 months due to locally advanced angiosarcoma. Given positive resection margin, radical re-excision with musculocutaneous musculus latissimus dorsi flap was done. 24 months later, a small sarcoma recurrence was detected near the upper resection margin, which was managed by radical re-excision. 52 months after radical operation, a metastasis was diagnosed by means of PET/CT in the contralateral axilla. Radical axillary dissection was performed (two metastases were found in axillary lymph nodes). According to follow-up, the patient has been free of any recurrence for 66 months from the radical surgery. CONCLUSION: Recommendations regarding the management of radiotherapy induced breast angiosarcoma are very vague due to limited evidence. Radical surgical excision with negative resection margins (potentially with complementary flap reconstruction) presents the fundamental approach to breast angiosarcoma.Key words: radiation-induced angiosarcoma - breast cancer - surgery.

Structural and Electronic Properties of Nitrogen-Doped Graphene.

We investigate the structural and electronic properties of nitrogen-doped epitaxial monolayer graphene and quasifreestanding monolayer graphene on 6H-SiC(0001) by the normal incidence x-ray standing wave technique and by angle-resolved photoelectron spectroscopy supported by density functional theory simulations. With the location of various nitrogen species uniquely identified, we observe that for the same doping procedure, the graphene support, consisting of substrate and interface, strongly influences the structural as well as the electronic properties of the resulting doped graphene layer. Compared to epitaxial graphene, quasifreestanding graphene is found to contain fewer nitrogen dopants. However, this lack of dopants is compensated by the proximity of nitrogen atoms at the interface that yield a similar number of charge carriers in graphene.

Probing Charges on the Atomic Scale by Means of Atomic Force Microscopy.

Kelvin probe force spectroscopy was used to characterize the charge distribution of individual molecules with polar bonds. Whereas this technique represents the charge distribution with moderate resolution for large tip-molecule separations, it fails for short distances. Here, we introduce a novel local force spectroscopy technique which allows one to better disentangle electrostatic from other contributions in the force signal. It enables one to obtain charge-related maps at even closer tip-sample distances, where the lateral resolution is further enhanced. This enhanced resolution allows one to resolve contrast variations along individual polar bonds.

Ortho and para hydrogen dimers on G/SiC(0001): combined STM and DFT study.

The hydrogen (H) dimer structures formed upon room-temperature H adsorption on single layer graphene (SLG) grown on SiC(0001) are addressed using a combined theoretical-experimental approach. Our study includes density functional theory (DFT) calculations for the full (6√3 × 6√3)R30° unit cell of the SLG/SiC(0001) substrate and atomically resolved scanning tunneling microscopy images determining simultaneously the graphene lattice and the internal structure of the H adsorbates. We show that H atoms normally group in chemisorbed coupled structures of different sizes and orientations. We make an atomic scale determination of the most stable experimental geometries, the small dimers and ellipsoid-shaped features, and we assign them to hydrogen adsorbed in para dimers and ortho dimers configuration, respectively, through comparison with the theory.

[Surgical rectocele repair - many techniques, few unambiguous conclusions]. / Chirurgická lécba rektokély - mnoho technik, málo jednoznacných záveru

INTRODUCTION: Surgical treatment of rectocele represents a controversial issue on the boundary between medical specialisations with many different corrective surgical techniques. Is it possible, based on the available knowledge, to determine an optimal operative technique for rectocele repair? METHODS: Complex literature search focusing on the identification of rectocele surgical repair studies in the MEDLINE, PubMed and Google Scholar databases. The aim of this paper is to offer a comprehensive review of the contemporary situation as regards rectocele surgical repair. RESULTS: There are four main possible approaches for rectocele repair - transvaginal, transanal, transperineal and transabdominal. Posterior colporrhaphy with levatoroplasty is the traditional transvaginal technique, performed at most gynaecological departments in various modifications. Defect-specific rectocele repair and mesh repair represent newer transvaginal techniques which offer better postoperative functional results, although with the risk of possible serious complications. Traditional transanal rectocele repair (vertical and horizontal plication of the rectovaginal septum) is currently performed only rarely due to its worse results in comparison with the transvaginal approach. Rectal resection using endostaplers (STARR and TRANSTAR techniques) is a modern transanal technique. Stapled rectocele repair leads to the correction of anorectal anatomical conditions and to the improvement of obstructive defecation symptoms with acceptable morbidity. Transperineal approach is usually used in patients with rectocele and anal incontinence due to a proven sphincter defect. Transabdominal laparoscopic approach is based on vaginorectopexy by means of mesh implantation, and it is indicated especially in patients with rectocele and enterocele. CONCLUSION: Based on the results of published studies, it is not possible to determine clear guidelines for rectocele surgical repair. Posterior colporrhaphy and stapled transanal repair are the most common techniques in practice. Prospective randomized studies focusing on the comparison between transvaginal and stapled transanal approach for rectocele repair are needed.

[Transtibial amputation: sagittal flaps in patients with diabetic foot syndrome]. / Sagitální typ bércové amputace u pacientu se syndromem diabetické nohy.

INTRODUCTION: Diabetic foot syndrome is defined by ulcer or destruction of leg tissues in patients with diabetes (diabetics) associated with infection, neuropathy and various degree of ischaemia (peripheral vascular disease). In Czech Republic in 2010 were registrated over 45 000 patients with diabetic foot syndrome. 8500 (diabetics) patients with diabetes undergone the surgery (any type of amputation). MATERIAL AND METHODS: In retrospective non randomized trial we evaluated the population of patients with lower limb amputation admitted to Clinic of Surgery FNO between 2010-1012. We introduce current (present) view to possibilities of lower limb amputations, historical problems and development of surgical methods. Special aspect is dedicated to sagital shank amputation. Detail description of operative (surgical) technique itself and crural region (area) anatomy. RESULTS: In 2010-2012 we achieved 146 lower limb amputations in shank, from that 27 sagital shank amputations( sagital operative method). We observed ( followed up) the number of reoperations, reasons that led to amputation, wounds healing by secondary intention, ites sources and necessity of revision due to postoperative hemorrhage. CONCLUSION: Effects of amputations on patientes quality of life. Social and socioeconomical impacts. Provably lower number of complications in sagital shank amputations compared to (in comparison with) conventional methods. Authors would like to point out and introduce interesting operation method to the general public.

Graphene etching on SiC grains as a path to interstellar polycyclic aromatic hydrocarbons formation.

Polycyclic aromatic hydrocarbons as well as other organic molecules appear among the most abundant observed species in interstellar space and are key molecules to understanding the prebiotic roots of life. However, their existence and abundance in space remain a puzzle. Here we present a new top-down route to form polycyclic aromatic hydrocarbons in large quantities in space. We show that aromatic species can be efficiently formed on the graphitized surface of the abundant silicon carbide stardust on exposure to atomic hydrogen under pressure and temperature conditions analogous to those of the interstellar medium. To this aim, we mimic the circumstellar environment using ultra-high vacuum chambers and investigate the SiC surface by in situ advanced characterization techniques combined with first-principles molecular dynamics calculations. These results suggest that top-down routes are crucial to astrochemistry to explain the abundance of organic species and to uncover the origin of unidentified infrared emission features from advanced observations.

Atomic structure affects the directional dependence of friction.

Friction between two objects can be understood by the making, stretching, and breaking of thousands of atomic-scale asperities. We have probed single atoms in a nonisotropic surface [the H-terminated Si(100) surface] with a lateral force microscope operating in noncontact mode. We show that these forces are measurably different, depending upon the direction. Experimentally, these differences are observable in both the line profiles and the maximum stiffnesses. Density functional theory calculations show a concerted motion of the whole Si dimer during the tip-sample interaction. These results demonstrate that on an asperity-by-asperity basis, the surface atomic structure plays a strong role in the directional dependence of friction.

[Anatomic-surgical study of intercostobrachial nerve (ICBN) course in axilla during I. and II. level of axilla clearance in breast cancer and malignant melanoma]. / Anatomicko-chirurgická studie prubehu interkostobrachiálních nervu (ICBN) v axile pri exenteraci I. a II. etáze axily u karcinomu prsu a maligního melanomu.

INTRODUCTION: The aim of this paper is to offer results of anatomic study of axillary course of intercostobrachial nerve (ICBN) and the effort of its saving in primary axilla clearance (PE), secondary clearance (SE) after previous positive sentinel nodes detection (SLN) and in re-clearance (RE) after previous axilla clearance in breast cancer and malignant melanoma. The correlation between possibility of ICBN saving and anatomic variant of ICBN and type of previous surgery was observed. MATERIAL AND METHODS: A total of 113 surgeries with the effort of description and preservation of ICBN were done between September 2007 and August 2011. Patients were divided into three groups according to type of surgery: primary clearance (PE), secondary clearance (SE) and re-clearance (RE). Results have been statistically tested using licensed statistical software Statgraphics. RESULTS: ICBN was found in 107 patients (94.7%), it wasnt found in six cases. There were eight different types of ICBN branching. Two most frequent variants formed majority of cases - 87 out of 107 (81.3%). The successful preservation of intact ICBN was in 86 patients (76.1%). ICBN was interrupted or not found in 10 patients (8.8%), partial injury of ICBN branches was detected in 17 cases (15.0%). If the most frequent variant of ICBN branching was present, the nerve was not injured in 42 out of 45 cases (93.3%). Statistical testing showed that non-standard anatomical branches are associated with higher risk of perioperative injury. The risk of injury was lowest in PE (21.6%) and the highest in RE (42.9%). The difference wasnt statistically significant because of low number of re-clearance cases in our study. CONCLUSION: The anatomy of ICBN in axilla is variable. The standard variant of ICBN course is the most frequent (the trunk coming out of second intercostal space; no branches in axillary course). If other variants are present, there is significantly higher risk of perioperative injury. ICBN preservation is possible also after previous axilla clearance. Preparation is more difficult and the risk of injury is increasing with the degree of previous surgery radicality.

Combined AFM and STM measurements of a silicene sheet grown on the Ag(111) surface.

In this paper, we present the first non-contact atomic force microscopy (nc-AFM) of a silicene on a silver (Ag) surface, obtained by combining non-contact atomic force microscopy and scanning tunneling microscopy (STM). STM images over large areas of silicene grown on the Ag(111) surface show both (√13 × âˆš13)R13.9° and (4 × 4) superstructures. For the widely observed (4 × 4) structure, the observed nc-AFM image is very similar to the one recorded by STM. The structure resolved by nc-AFM is compatible with only one out of two silicon atoms being visible. This indicates unambiguously a strong buckling of the silicene honeycomb layer.

Reversal of atomic contrast in scanning probe microscopy on (111) metal surfaces.

We study the origin of atomic contrast on Cu(111) and Pt(111) surfaces probed by a non-contact atomic force microscope and scanning tunnelling microscope. First-principles simulations of the interaction between the atoms of the scanning tip and those of the probed surface show a dependence of the resulting contrast on the tip-sample distance and reveal a close relation between contrast changes and relaxation of atomic positions in both the tip and the sample. Contrast reversion around the distance where the short-range attractive atomic force reaches its maximum is predicted for both types of microscopies. We also demonstrate a relation between the maximal attractive force in a F-z atomic force spectroscopy and the chemical identity of the apex atom on the imaging tip.