Equimolar As4S4/Fe3O4 Nanocomposites Fabricated by Dry and Wet Mechanochemistry: Some Insights on the Magnetic-Fluorescent Functionalization of an Old Drug.

Multifunctional nanocomposites from an equimolar As4S4/Fe3O4 cut section have been successfully fabricated from coarse-grained bulky counterparts, employing two-step mechanochemical processing in a high-energy mill operational in dry- and wet-milling modes (in an aqueous solution of Poloxamer 407 acting as a surfactant). As was inferred from the X-ray diffraction analysis, these surfactant-free and surfactant-capped nanocomposites are ß-As4S4-bearing nanocrystalline-amorphous substances supplemented by an iso-compositional amorphous phase (a-AsS), both principal constituents (monoclinic ß-As4S4 and cubic Fe3O4) being core-shell structured and enriched after wet milling by contamination products (such as nanocrystalline-amorphous zirconia), suppressing their nanocrystalline behavior. The fluorescence and magnetic properties of these nanocomposites are intricate, being tuned by the sizes of the nanoparticles and their interfaces, dependent on storage after nanocomposite fabrication. A specific core-shell arrangement consisted of inner and outer shell interfaces around quantum-confined nm-sized ß-As4S4 crystallites hosting a-AsS, and the capping agent is responsible for the blue-cyan fluorescence in as-fabricated Poloxamer capped nanocomposites peaking at ~417 nm and ~442 nm, while fluorescence quenching in one-year-aged nanocomposites is explained in terms of their destroyed core-shell architectures. The magnetic co-functionalization of these nanocomposites is defined by size-extended heterogeneous shells around homogeneous nanocrystalline Fe3O4 cores, composed by an admixture of amorphous phase (a-AsS), nanocrystalline-amorphous zirconia as products of contamination in the wet-milling mode, and surfactant.

Evaluating the impact of an anti-microbial silver-impregnated surgical dressing on wound infections and healing: A randomised clinical trial.

StopBac is an innovative silver-impregnated antimicrobial dressing specifically designed to reduce surgical site infections and enhance healing. The primary objective of this study was to compare infection healing rate at 30 days after surgery between primarily closed surgical wounds covered with StopBac and those covered with Cosmorpor, a standard surgical dressing. Between 1.3.2023 and 30.4.2023, we conducted a prospective screening of all patients undergoing surgical operations within a single surgical department. Patients were randomised into either the Cosmopor group or the StopBac group. Outcome measures were superficial and deep surgical site infections and healed wounds. Data concerning patient and surgical factors were prospectively collected and analysed. The analysis comprised 275 patients, divided into two groups: 140 patients in the StopBac group and 135 in the Cosmopor group. The StopBac dressing was associated with a reduced rate of infection, with an odds ratio of 0.288 (p < 0.001), and an increased likelihood of wound healing at 30 days after surgery. The odds ratio for healing at 30 days was 4.661 (p < 0.001). StopBac was associated with a lower incidence of surgical wound infections and a higher probability of healing at 30 days after surgery, when compared with standard dressing.

The manipulation of natural mineral chalcopyrite CuFeS2via mechanochemistry: properties and thermoelectric potential.

In this study, the properties of the natural mineral chalcopyrite CuFeS2 after mechanical activation in a planetary mill were studied. The intensity of mechanical activation was controlled by changing the revolutions of the mill in the range 100-600 min-1. A series of characterization techniques, such as XRD, SEM, TEM, TA (DTA, TG, and DTG), particle size analysis, and UV-vis spectroscopy was applied and reactivity studies were also performed. Several new features were revealed for the mechanically activated chalcopyrite, e.g. the poly-modal distribution of produced nanoparticles on the micrometer scale, agglomeration effects by prolonged milling, possibility to modify the shape of the particles, X-ray amorphization and a shift from a non-cubic (tetragonal) structure to pseudo-cubic structure. The thermoelectric response was evaluated on the "softly" compacted powder via the spark plasma sintering method (very short holding time, low sintering temperature, and moderate pressure) by measuring the Seebeck coefficient and electrical and thermal conductivity above room temperature. The milling process produced samples with lower resistivity compared to the original non-activated sample. The Seebeck data close to zero confirmed the "compensated" character of natural chalcopyrite, reflecting its close-to stoichiometric composition with low concentration of both n- and p-type charge carriers. Alternatively, an evident correlation between thermal conductivity and energy supply by milling was observed with the possibility of band gap manipulation, which is associated with the energy delivered by the milling procedure.

Management of an aneurysmal arteriovenous fistula in kidney transplant recipients.

Aneurysms remain the most common complication of an arteriovenous fistula created for dialysis access. The management of an aneurysmal arteriovenous fistula (AAVF) in kidney transplant recipients remains contentious with a lack of clear clinical guidelines. Recipients of a functioning graft do not require the fistula for dialysis access, however risk of graft failure and needing the access at a future date must be considered. In this review we outline the current evidence in the assessment and management of a transplant recipient with an AAVF. We will describe our recommended five-step approach to assessing an AAVF in transplant patients; 1.) Define AAVF 2.) Risk assess AAVF 3.) Assess transplant graft function and future graft failure risk 4.) Consider future renal replacement therapy options 5.) Vascular mapping to assess future vascular access options. Then we will describe the current therapeutic options and when they would most appropriately be employed.

Segmental Versus Partial Portomesenteric Resection in Pancreatectomy for Pancreatic Cancer.

INTRODUCTION: Portomesenteric vein resections are a well-established part of pancreatectomies for advanced tumors that invade the portomesenteric axis. There are two main types of portomesenteric resections: partial resections, where only part of the venous wall is removed and segmental resection, where the full circumference of the wall is removed. The aim of this study is to compare short-term and long-term outcomes between these two techniques. METHODS: This is a single-centre retrospective study of the patients with pancreatic cancer who underwent pancreatectomy with portomesenteric vein resections between November 2009 and May 2021. RESULTS: From a total of 773 pancreatic cancer procedures, 43 (6%) patients underwent pancreatectomy with portomesenteric resections: 17 partial and 26 segmental. The overall median survival was 11 mo. For the partial portomesenteric resections, the median survival was 29 mo, and for the segmental portomesenteric resections, it was 10 mo (P = 0.019). The primary patency of the reconstructed veins after partial resection was 100% and after segmental resection was 92% (P = 0.220). Negative resection margins were achieved in 13 patients (76%) who underwent partial portomesenteric vein resection and 23 patients (88%) who underwent segmental portomesenteric vein resection. CONCLUSIONS: |Although this study is associated with worse survival, segmental resection is often the only way to safely remove pancreatic tumors with negative resection margins.

Pancreaticoduodenal artery aneurysm associated with coeliac trunk occlusion treated with aorto-hepatic bypass and aneurysm resection.

Pancreaticoduodenal artery aneurysms are rare visceral artery aneurysms that may be associated with stenosis of the coeliac trunk. We present a case of a 48-year-old woman with a symptomatic aneurysm of the inferior pancreaticoduodenal artery caused by occlusion of the coeliac trunk due to median arcuate ligament syndrome. The patient was treated with an aorto-hepatic bypass and excision of the aneurysm. We discuss the case and the complexities and controversies in the treatment of this disease.

Mechanochemical synthesis of non-stoichiometric copper sulfide Cu1.8S applicable as a photocatalyst and antibacterial agent and synthesis scalability verification.

An effort to prepare different non-stoichiometric CuxSy compounds starting from elemental precursors using mechanochemistry was made in this study. However, out of the 7 stoichiometries tested, it was only possible to obtain three phases: covellite CuS, chalcocite Cu2S and digenite Cu1.8S and their mixtures. To obtain the digenite phase with the highest purity, the Cu : S stoichiometric ratio needed to be fixed at 1.6 : 1. The reaction between copper and sulfur was completed within a second range, however, milling was performed for up to 15 minutes until the equilibrium in phase composition between digenite and covellite was reached. The possibility of preparing the product in a 300 g batch by eccentric vibratory milling in 30 minutes was successfully verified at the end. The estimated crystallite sizes for the digenite Cu1.8S obtained via lab-scale and scalable experiments were around 12 and 17 nm, respectively. The obtained products were found to be efficient photocatalysts under visible light irradiation in the presence of hydrogen peroxide, being capable of the complete degradation of the Methyl Orange dye in a concentration of 10 mg L-1 in 2 hours. Finally, the antibacterial potential of both lab-scale and large-scale industrial products was proven and, regardless of the manufacturing scale, the nanoparticles retained their properties against bacterial cells.

Identifying classification systems regarding vascular access for haemodialysis: protocol for a scoping review.

INTRODUCTION: Classifications are important clinical tools that enable data arrangement, patient categorisation and comparative research. The care of patients with end-stage renal disease who have vascular access requires collaboration of several specialists. In such a field, where several different specialties overlap, strong evidence and well-grounded recommendations for good practice are essential. In this protocol, we aim to search the literature to identify classification systems regarding vascular access for haemodialysis. This protocol serves as a pragmatic tool for setting a systematic approach using scoping review methodology. It also aims to make the study transparent and avoid potential duplication. METHODS AND ANALYSIS: We will follow the Joanna Briggs Institute methodology for the conduct of scoping reviews during the course of the proposed review. Scopus, Web of Science, PubMed, Google Scholar and the ClinicalTrials.gov registry will be searched by two researchers. Titles and abstracts will be screened and articles featuring classifications regarding vascular access for haemodialysis will be eligible for full-text analysis. There will be no age, sex or race limitation for the study populations. The title and abstract (if abstract available) must be in English but there will be no language restrictions for full-text review. Databases will be searched from inception to the date of search. All patients indicated for creation or placement of vascular access will be eligible, as well as patients with already existing vascular access. Classifications regarding preprocedural assessment, vascular access insertion or creation, complications and their management will be included in the study. Classifications regarding peritoneal dialysis will not be eligible. A comprehensive summary of the available evidence will be presented. ETHICS AND DISSEMINATION: The protocol and the review are exempt from ethical approval as there is no direct patient involvement and the review will summarise data from already published literature. The final article will be submitted to a peer-reviewed scientific journal.

Properties of CuFeS2/TiO2 Nanocomposite Prepared by Mechanochemical Synthesis.

CuFeS2/TiO2 nanocomposite has been prepared by a simple, low-cost mechanochemical route to assess its visible-light-driven photocatalytic efficiency in Methyl Orange azo dye decolorization. The structural and microstructural characterization was studied using X-ray diffraction and high-resolution transmission electron microscopy. The presence of both components in the composite and a partial anatase-to-rutile phase transformation was proven by X-ray diffraction. Both components exhibit crystallite size below 10 nm. The crystallite size of both phases in the range of 10-20 nm was found and confirmed by TEM. Surface and morphological properties were characterized by scanning electron microscopy and nitrogen adsorption measurement. Scanning electron microscopy has shown that the nanoparticles are agglomerated into larger grains. The specific surface area of the nanocomposite was determined to be 21.2 m2·g-1. Optical properties using UV-Vis and photoluminescence spectroscopy were also investigated. CuFeS2/TiO2 nanocomposite exhibits strong absorption with the determined optical band gap 2.75 eV. Electron paramagnetic resonance analysis has found two types of paramagnetic ions in the nanocomposite. Mössbauer spectra showed the existence of antiferromagnetic and paramagnetic spin structure in the nanocomposite. The CuFeS2/TiO2 nanocomposite showed the highest discoloration activity with a MO conversion of ~ 74% after 120 min irradiation. This study has shown the possibility to prepare nanocomposite material with enhanced photocatalytic activity of decoloration of MO in the visible range by an environmentally friendly manner.

Ternary and Quaternary Nanocrystalline Cu-Based Sulfides as Perspective Antibacterial Materials Mechanochemically Synthesized in a Scalable Fashion.

Twelve Cu-based ternary (Cu-Me1-S, Me1 = Fe, Sn, or Sb) and quaternary (Cu-Me2-Sn-S, Me2 = Fe, Zn, or V) nanocrystalline sulfides are shown as perspective antibacterial materials here. They were prepared from elemental precursors by a one-step solvent-free mechanochemical synthesis in a 100 g batch using scalable eccentric vibratory ball milling. Most of the products have shown strong antibacterial activity against Escherichia coli and Staphylococcus aureus bacteria. For instance, stannite Cu2FeSnS4 and mohite Cu2SnS3 were the most active against E. coli, whereas kesterite Cu2ZnSnS4 and rhodostannite Cu2FeSn3S8 exhibited the highest antibacterial activity against S. aureus. In general, stannite has shown the best antibacterial properties out of all the studied samples. Five out of twelve products have been prepared using mechanochemical synthesis for the first time in a scalable fashion here. The presented synthetic approach is a promising alternative to traditional syntheses of nanomaterials suitable for biological applications and shows ternary and quaternary sulfides as potential candidates for the next-generation antibacterial agents.

Silver-Based Dressings in the Prevention of the Incisional Surgical Site Infection: A Prospective Multicenter Observational Controlled Trial.

Background: A new silver-based dressing has been designed to reduce surgical sited infections. Patients and Methods: A prospective multicenter observational study was conducted from January 2020 to October 2021. Patients with and without silver-based dressing after surgical incision were observed and their data analyzed. The study aimed to assess the incidence of incisional surgical site infection and primary healing after general surgery procedures. Results: Overall, 218 patients with silver-based (n = 109) and conventional silver-free dressing (n = 109) were analyzed. Surgical site infection (SSI) and primary incision healing were reported in 10 (9.2%) versus 21 (19.3%) (p = 0.037) and in 95 (87.2%) versus 86 (78.9%) (p = 0.107) patients treated with and without silver-based dressing, respectively. Conclusions: Silver-based dressing demonstrated a lower incidence of incisional SSI and improved primary healing in comparison with patients in whom conventional non-silver-based dressing has been used.

The Art of Positronics in Contemporary Nanomaterials Science: A Case Study of Sub-Nanometer Scaled Glassy Arsenoselenides.

The possibilities surrounding positronics, a versatile noninvasive tool employing annihilating positrons to probe atomic-deficient sub-nanometric imperfections in a condensed matter, are analyzed in application to glassy arsenoselenides g-AsxSe100-x (0 < x < 65), subjected to dry and wet (in 0.5% PVP water solution) nanomilling. A preliminary analysis was performed within a modified two-state simple trapping model (STM), assuming slight contributions from bound positron-electron (Ps, positronium) states. Positron trapping in g-AsxSe100-x/PVP nanocomposites was modified by an enriched population of Ps-decay sites in PVP. This was proven within a three-state STM, assuming two additive inputs in an overall trapping arising from distinct positron and Ps-related states. Formalism of x3-x2-CDA (coupling decomposition algorithm), describing the conversion of Ps-decay sites into positron traps, was applied to identify volumetric nanostructurization in wet-milled g-As-Se, with respect to dry-milled ones. Under wet nanomilling, the Ps-decay sites stabilized in inter-particle triple junctions filled with PVP replaced positron traps in dry-milled substances, the latter corresponding to multi-atomic vacancies in mostly negative environments of Se atoms. With increased Se content, these traps were agglomerated due to an abundant amount of Se-Se bonds. Three-component lifetime spectra with nanostructurally- and compositionally-tuned Ps-decay inputs and average lifetimes serve as a basis to correctly understand the specific "rainbow" effects observed in the row from pelletized PVP to wet-milled, dry-milled, and unmilled samples.

A systematic review and meta-analysis on the management of concomitant abdominal aortic aneurysms and renal tumours.

OBJECTIVES: The treatment of concomitant abdominal aortic aneurysms and renal tumours is controversial. The aim of this study was to ascertain which of the following three strategies, one-stage open aneurysm repair and nephrectomy, two-stage open aneurysm repair and nephrectomy or two-stage endovascular aneurysm repair and nephrectomy, is the best approach. METHODS: systematic review and meta-analysis of articles published between January 1992 and April 2021 describing the treatment of concomitant abdominal aortic aneurysms and renal tumours. RESULTS: A total of 1168 records were identified. After the selection process, 12 studies with data on 89 patients were included. Sixty-two patients underwent one-stage open procedures, 18 patients underwent two-stage open procedures and nine underwent two-stage endovascular procedures. The overall postoperative mortality was 0.82% (95% CI, 0.00-4.61). The postoperative mortality for one-stage open procedures was 3.09% (95% CI, 0.00-10.11). No deaths occurred in the postoperative period open two-stage procedures or two-stage endovascular procedures. The weighted postoperative morbidity for all procedures was 23.86% (95% CI, 12.64-35.08) and for open one-stage procedures was 37.40% (95% CI, 14.33-60.47). Data concerning postoperative complications of two-stage open procedures were extractable from only one patient in whom no complications were reported. Two postoperative complications were reported after two-stage endovascular procedures from a total of six patients with extractable postoperative data. We were unable to perform meta-analysis on long-term outcomes as the data were reported non-uniformly. CONCLUSION: There is currently no evidence to suggest that any procedure is associated with better outcomes. However, a one-stage open approach was the most commonly used option, favoured as it avoids delaying treatment of either of the conditions. Two-stage open procedures were preferred in cases where the surgical risk of a one-stage procedure was higher than the potential benefit. For such cases, two-stage endovascular repair is becoming more popular as a less invasive approach.

VariClose® vein sealing system is inferior to endovenous laser ablation for the treatment of varicose veins.

BACKGROUND: One of the three commercially available cyanoacrylate venous glues used for the treatment of saphenous vein insufficiency is the VariClose® vein sealing system. Previous studies have documented a high rate of occlusion and minimal postoperative complications. The aim of this study was to compare occlusion rates and clinical outcomes of endovenous laser treatment with the VariClose® vein sealing system in the treatment of truncal vein insufficiency. PATIENTS AND METHODS: Retrospective non-randomized single center study with prospectively collected data comparing endovenous laser treatment and VariClose® procedures between April 2018 and November 2019. RESULTS: VariClose® was used in 27 patients (30 veins) and endovenous laser treatment in 42 patients (51 veins). The occlusion rate at one, three, and six months were 96%, 85%, and 65% for VariClose® procedures and 100%, 100%, and 97% for endovenous laser treatment procedures (p = 0.01), respectively. Reduction of VCSS scores before treatment and at the last postoperative follow-up visit in the VariClose® group dropped by an average of 1.8 ± 1.6 and in the endovenous laser treatment by an average of 3.3 ± 2.9 (p = 0.01). CONCLUSION: VariClose® vein sealing system is inferior to endovenous laser treatment as a treatment option for varicose veins as it has a higher recanalization rate.

Experience with VariClose® vein sealing system in the Czech Republic.

OBJECTIVES: The aim of this study was to assess occlusion rates of saphenous veins treated with the VariClose vein sealing system. METHODS: A retrospective analysis including a total of 64 patients from four centres from the Czech Republic. Occlusion was defined as a non-compressible vein with absence of flow with exception to the first 3 cm from the saphenofemoral or saphenopopliteal junction on duplex ultrasound. RESULTS: In 64 patients a total of 79 veins were treated. Technical success of the procedure was achieved in 74 (94%) of cases. The mean follow-up was 5.5 months. The closure rates calculated by the Kaplan-Meier method at 1, 3, 6 and 12 months were 94%, 85%, 69% and 36%, respectively, and there were no significant differences between centers. The average difference in VCSS score before and after the procedure was 1.8. CONCLUSIONS: The present study demonstrated surprisingly worse occlusion rates than the current literature.

How Czech and Slovak vascular surgeons and nephrologists accept recommendations of the European Society of Vascular Surgery - survey study.

Arteriovenous access (AVA) is the cornerstone for the long-term haemodialysis treatment in the patient with end-stage kidney disease. Nowadays, European Society of Vascular Surgery (ESVS) has presented clinical guidelines regarding all aspects of AVA. The aim of the study was to identify acceptance rate of selected ESVS recommendations among Czech and Slovak vascular surgeons and nephrologists. We carried out a prospective analysis of 7 questions from an online survey collected from January to February 2020. 211 (33 %) of 646 participants responded to the survey. Questions were divided into two groups, general and surgical. General questions were for both nephrologist and vascular surgeons. Surgical questions were evaluated only for vascular surgeons. In the first group 190 (90 %) respondents accept, that extremity dominance is important for location of AVA, 186 (89 %) agree that clinically suspected venous hypertension/central vein occlusion is an indication for fistulography, 111 (53 %) agree, that indwelling central venous catheter/pacemaker is an indication for AVA creation in the opposite side. In the second group, 50 (57 %) agree that patients before AVA creation should be examined with a tourniquet prior to surgery, 45 (51 %) agree, that pre-operative ultrasonography mapping is recommended, 66 (75 %) agree, that the inner radial artery and the cephalic vein should be more than 2.0 mm, and only 9 (10 %) respondents agree that regional anaesthesia is preferred over local anaesthesia for AVA creation. In both Czech and Slovak Republic, preoperative planning is not uniform and ESVS recommendations for AVA are accepted at the level of 57 %.

Mechanochemistry for Energy Materials: Impact of High-Energy Milling on Chemical, Electric and Thermal Transport Properties of Chalcopyrite CuFeS2 Nanoparticles.

Chalcopyrite CuFeS2 , a semiconductor with applications in chemical sector and energy conversion engineering, was synthetized in a planetary mill from elemental precursors. The synthesis is environmentally friendly, waste-free and inexpensive. The synthesized nano-powders were characterized by XRD, SEM, EDX, BET and UV/Vis techniques, tests of chemical reactivity and, namely, thermoelectric performance of sintered ceramics followed. The crystallite size of ∼13 nm and the strain of ∼17 were calculated for CuFeS2 powders milled for 60, 120, 180 and 240 min, respectively. The evolution of characteristic band gaps, Eg, and the rate constant of leaching, k, of nano-powders are corroborated by the universal evolution of the parameter SBET /X (SBET -specific surface area, X-crystallinity) introduced for complex characterization of mechanochemically activated solids in various fields such as chemical engineering and/or energy conversion. The focus on non-doped semiconducting CuFeS2 enabled to assess the role of impurities, which critically and often negatively influence the thermoelectric properties.

High-Energy Mechanical Milling-Driven Reamorphization in Glassy Arsenic Monoselenide: On the Path of Tailoring Special Molecular-Network Glasses.

The impact of high-energy milling on glassy arsenic monoselenide g-AsSe is studied with X-ray diffraction applied to diffuse peak-halos proper to intermediate- and extended-range ordering revealed in first and second sharp diffraction peaks (FSDP and SSDP). A straightforward interpretation of this effect is developed within the modified microcrystalline approach, treating "amorphous" halos as a superposition of the broadened Bragg diffraction reflexes from remnants of some inter-planar correlations, supplemented by the Ehrenfest diffraction reflexes from most prominent inter-molecular and inter-atomic correlations belonging to these quasi-crystalline remnants. Under nanomilling, the cage-like As4Se4 molecules are merely destroyed in g-AsSe, facilitating a more polymerized chain-like network. The effect of nanomilling-driven molecular-to-network reamorphization results in a fragmentation impact on the correlation length of FSDP-responsible entities (due to an increase in the FSDP width and position). A breakdown in intermediate-range ordering is accompanied by changes in extended-range ordering due to the high-angular shift and broadening of the SSDP. A breakdown in the intermediate-range order is revealed in the destruction of most distant inter-atomic correlations, which belong to remnants of some quasi-crystalline planes, whereas the longer correlations dominate in the extended-range order. The microstructure scenarios of milling-driven reamorphization originated from the As4Se4 molecule, and its network derivatives are identified with an ab initio quantum-chemical cluster modeling code (CINCA).

The arteriovenous access stage (AVAS) classification.

BACKGROUND: Key anatomical factors mean that individuals needing arteriovenous access are unique and have different possibilities for fistula creation. The aim of this article is to describe a new classification system for all patients needing haemodialysis vascular access in the upper extremity with the purpose to simplify sharing the information about suitability for surgical access creation depending on vascular anatomy. METHODS: According to the patient's vascular anatomy in right and left superior extremities, patients were separated into three arteriovenous access stages (AVAS). The AVAS was validated by three blinded observers using a sample of 70 upper limb arteriovenous maps that were performed using ultrasound on patients referred for vascular access assessment. A sample size calculation was performed and calculated that for three observers, a minimum of 67 maps were required to confirm significant agreement at a Kappa value of 0.9 (95% confidence interval 0.75-0.99). RESULTS: The Kappa value for inter-rater reliability using Fleiss' Kappa coefficient was 0.94 and all patients fitted into the AVAS classification system. CONCLUSION: The AVAS classification system is a simplified way to share information about vascular access options based on a patient's vascular anatomy with high inter-rater reliability.