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The surface activities and application properties of aqueous solution surfactants are greatly influenced by their structure, especially the spacer group that connects the polar head groups. Herein, four new non‐ionic Gemini surfactants with different spacers were designed and synthesized, and their surfactant properties and biodegradability were studied. The synthesis of these compounds involves a two‐step procedure. The first step is the formation of an amide from lauric acid and diethanolamine. The second step is the reaction of lauryl diethanolamide with four different spacers, the latter being flexible‐hydrophilic, and rigid‐hydrophobic in structure, respectively. Their structures were characterized using 1H NMR, 13C NMR, FT‐IR, and ESI‐MS. The critical micelle concentration (CMC), the surface tension at CMC (γCMC), the efficiency of these compounds to reduce the surface tension by 20 mN/m (C20 and pC20), the effectiveness (πCMC), the maximum surface excess (Γmax), and the minimum surface area (Amin) were measured at 20, 40, and 50°C. The molecular architecture of the spacers in these compounds strongly influences the thermodynamic parameters, such as the standard change for Gibbs free energy of adsorption (ΔG°ads) and the standard change for Gibbs free energy of micellization (ΔG°mic). The ability of these surfactants to reduce surface tension is particularly good, but their distinguishing characteristic is their high relative propensity to form micellar aggregates. This aggregation ability improves as the hydrophilicity and flexibility of the spacer increase. Finally, in less than 30 days, all non‐ionic Gemini surfactants were determined to be 99% biodegradable in river water. [ABSTRACT FROM AUTHOR]

The clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins are adaptive immune system found in bacteria and archaea. This system targets the genomes of invading pathogens in the bacteria for degradation and incorporates the fragments in the CRISPR cassettes. Because of its capacity to detect DNA and RNA, CRISPR/Cas system has emerged as a significant technique in molecular biology and has been adapted for genome editing. Also, it is been used in pathogen diagnostics, gene therapy, epigenetic regulation, and library construction. Although, CRISPR Cas system techniques have some limitations, they are the most promising diagnostic methods of the modern science and make it easy to use when combined with other techniques such as isothermal nucleic acid technique. Diagnostic methods such as real-time qPCR and isothermal nucleic acid amplification rely on a chain of reactions to detect pathogens. A single error in the preparation or experimental process can result in non-specific amplification. Furthermore, qPCR techniques are costly because they require skilled personnel and state-of-the-art equipment to carry out a series of procedures. Therefore, there is an urgent need to develop diagnostic methods that are simple and fast to utilize, particularly at the point of treatment. To answer this call, in the past decade, CRISPR/Cas system tools have been developing and actively used in detecting nucleic acids in pathogenic materials. In this review, we will shed light on the discovery of CRISPR/Cas and the CRISPR/Cas adaptive immune systems. Here, we will present a brief history of the classification of CRISPR/Cas systems, their applications in disease control, CRISPR/Cas13 nomenclature, and diagnostic tools. Additionally, we will discuss how the CRISPR/Cas13 system can detect noninfectious diseases. Further, we will conclude with the broader impact of CRISPR technologies on preventing pathogens, a serious human health threat. [ABSTRACT FROM AUTHOR]

Electrical substations must operate reliably and effectively no matter the environment they are located in, and they must also repair damage fast. Due to a number of problems that occurred throughout the switching and manufacturing processes, including as delamination, protrusion, depression, gap, etc., spacer failures of the gas insulated busduct (GIB) have recently been discovered. These defects have a major negative effect on the spacer's surface, which de-energises the gas-insulated busduct device and causes a large financial loss. For the purpose of studying the electric field stress at the triple junction, a functionally graded material (FGM) spacer is designed in this paper for a 3 phase GIB with particle along with protrusion and depression abnomalities. The stress is reduced by inserting metal inserts at the end of the enclosure. Functionally graded materials are spatially distributed with a variety of filler materials to achieve uniform electric field stress by doping them with various permittivity values. Simulation is carried out on a bulb type spacer in 3 phase gas insulated busduct with different voltages and FGM gradings. The impact of grading's on electric field stress is studied and further reduced with the introduction of the metal insert (MI) to the FGM spacer. The simulated results with and without MI are discussed and analysed to demonstrate the viability of the proposed spacer. [ABSTRACT FROM AUTHOR]

In radiotherapy for pediatric abdominal tumors, determining the effect of concurrent chemotherapy on polyglycolic acid (PGA) spacers is crucial; yet this effect has not been validated. Therefore, we aimed to evaluate the impact of cyclophosphamide (CPA) chemotherapy on the PGA spacer using a rat model. Twenty-four rats were implanted with the spacer, and morphological changes in the spacer were assessed on CT for both the CPA-dosed group (40 mg/kg) and the control group. The size and volume of the spacer were quantified using CT, while the degree of adhesion and microscopic examination of the tissue were determined using pathology specimens. Morphologically, the size of the spacer decreased over time in both the CPA-dosed and control groups, with no significant differences observed between groups. No significant differences in adhesion were observed between the two groups. Macrophages were observed around the PGA fibers, suggesting their involvement in the degradation of the PGA spacer. These results suggest that CPA does not cause significant clinically problematic degradation or adverse tissue reactions to the PGA spacer. This study reinforced the benefits of PGA spacers; however, future research focusing on in vivo longitudinal monitoring of individual rats, as well as on humans, is required. [ABSTRACT FROM AUTHOR]

Auxetics are materials displaying a negative Poisson's ratio, i.e., getting thicker in one or both transverse axes when subject to strain. In 2018, liquid crystal elastomers (LCEs) displaying auxetic behaviour, achieved via a biaxial reorientation, were first reported. Studies have since focused on determining the physics underpinning the auxetic response, with investigations into structure–property relationships within these systems so far overlooked. Herein, we report the first structure–property relationships in auxetic LCEs, examining the effect of changes to the length of the spacer chain. We demonstrate that for LCEs with between six and four carbons in the spacer, an auxetic response is observed, with the threshold strain required to achieve this response varying from 56% (six carbon spacers) to 81% (four carbon spacers). We also demonstrate that Poisson's ratios as low as −1.3 can be achieved. Further, we report that the LCEs display smectic phases with spacers of seven or more carbons; the resulting internal constraints cause low strains at failure, preventing an auxetic response. We also investigate the dependence of the auxetic threshold on the dynamics of the samples, finding that when accounting for the glass transition temperature of the LCEs, the auxetic thresholds converge around 56%, regardless of spacer length. [ABSTRACT FROM AUTHOR]

In well cementing operation, a certain amount of spacer needs to be pumped into the wellbore before injecting cement slurries. In offshore well cementing, the preparation of spacer requires heavy manual labor, and the labor intensity is quite high, resulting in low operation efficiency and poor control on the quantities of the spacer additives. To solve this problem, liquid additives are used to replace the solids additives in formulating the spacer, and the liquid additives are added through the additive addition system LAS. Using this technique, the traditional heavy physical labor in formulating a spacer is replaced with intelligent operation, the labor intensity is lowered, the efficiency of well cementing operation is increased, and the labor costs are reduced. A liquid spacer additive C-S70L is prepared through inverse emulsion polymerization. Using C-S70L as the core additive, a spacer suitable for injection using the LAS is formulated. This spacer can be used in temperature range of 20 - 120 °C and density range of 1.30 – 1.70 g/cm³. It has good suspending stability (no settling after hot rolling), a rheology that is easy to adjust, a fluid loss that is controllable and good compatibility. [ABSTRACT FROM AUTHOR]

Background: Designed to help treat pain and loss of function after rotator cuff repair, allograft spacer procedures utilize a graft to act as a spacer in the subacromial space, decreasing pain from impingement of the greater tuberosity on the acromion at the extremes of overhead motion. Purpose: To evaluate the biomechanical characteristics of secured versus unsecured tensor fascia lata allografts used in an allograft spacer procedure. Study Design: Controlled laboratory study. Methods: A total of 8 fresh-frozen cadaveric shoulder specimens were used. There were 4 conditions tested: (1) intact rotator cuff, (2) stage III rotator cuff tear (complete supraspinatus tendon and superior one-half of the infraspinatus tendon), (3) unsecured tensor fascia lata graft, and (4) secured tensor fascia lata graft. Both superior and posterior translation of the humeral head were calculated in each condition. A 4-cm × 5-cm × 6-mm tensor fascia lata graft was used in the subacromial space to act as a spacer. Grafts were secured at the lateral edge of the native rotator cuff footprint with 2 knotless anchors. Results: With unbalanced loading, both secured and unsecured grafts varied in their ability to limit superior and posterior translation at various rotation angles back to levels seen with intact rotator cuffs at 0° and 20° of abduction. During balanced loading, both unsecured and secured grafts limited superior and posterior translation more than those seen in the rotator cuff–deficient condition (P <.01) and similar to those seen in the intact condition (P >.05). The secured and unsecured grafts allowed similar amounts of translation at every position with both unbalanced and balanced loading (P >.05). Finally, total graft motion was <7 mm in all positions. Conclusion: Unsecured tensor fascia lata grafts were biomechanically equivalent to secured grafts when used during allograft spacer procedures. Clinical Relevance: While both grafts were successful at limiting superior and posterior translation of the humeral head during early range of motion, the unsecured graft represents a cheaper, easier option to utilize during allograft spacer procedures. [ABSTRACT FROM AUTHOR]

This study employed a comprehensive genome-mining approach to characterize CRISPR-Cas systems in Lactobacillus delbrueckii strains. The analysis involved retrieving 105 genome sequences to explore the variety, occurrence, and evolution of CRISPR-Cas systems within the species. Homology analysis of spacer sequences in detected CRISPR arrays was conducted to assess the variety of target phages and plasmids. The evolutionary trajectories of spaceromes in each subtype of CRISPR arrays were determined by analyzing acquisition and deletion events under the selection pressure of foreign plasmids and phages. Among the analyzed strains, 53 contained only one CRISPR-Cas locus, 11 had two loci, and 21 featured three loci with complete CRISPR-Cas systems. Subtype designation of the results of current study revealed that 56 % of these systems belong to subtypes I-E/I-C, 23 % to subtypes III-A/III-D, and 17 % to subtype II-A. Notably, certain plasmids were found to be specifically targeted by distinct CRISPR array systems. The comparison of spacer sequences with phage genomes indicated that strains containing only CRISPR-Cas type-I systems targeted a broader range of phages. In conclusion, this study highlights the diversity of the three identified CRISPR-Cas types in L. delbrueckii strains and emphasizes their significant role in defense against phage invasion.

The objective is to minimize the inaccuracies in two-step impressions by homogenizing the polymerization shrinkage of elastomeric impression material in fixed prosthesis fabrication. The objective is accomplished by the technique of spacer adaptation and custom tray fabrication for two-step impressions. The technique makes the use of two vacuum-adapted spacers, selected based on the viscosity of elastomeric impression, and a vacuum-adapted custom tray. The procedure of using the specially fabricated custom tray for impression making is also presented. Consistent thickness of the two different viscosities of impression material is maintained due to vacuum adaptation of the spacers. This homogenizes the polymerization shrinkage of the elastomeric material in different regions of impression, as uniform space is occupied by the material in the space created by the spacer. The procedure of vacuum adaption of the tray material also limits the dimensional change of the tray. The technique minimizes the inaccuracies of impression by homogenizing the polymerization shrinkage of the elastomeric impression, thus promising a well-fitting prosthesis.

Spider silk—an environmentally friendly protein‐based material—is widely recognized for its extraordinary mechanical properties. Biomimetic spider silk‐like fibers made from recombinant spider silk proteins (spidroins) currently falls short compared to natural silks in terms of mechanical performance. In this study, it is discovered that spiders use structural conversion of molecular enhancers—conserved globular 127‐residue spacer domains—to make strong silk fibers. This domain lacks poly‐Ala motifs but interestingly contains motifs that are similar to human amyloidogenic motifs, and that it self‐assembles into amyloid‐like fibrils through a non‐nucleation‐dependent pathway, likely to avoid the formation of cytotoxic intermediates. Incorporating this spacer domain into a recombinant chimeric spidroin facilitates self‐assembly into silk‐like fibers, increases fiber molecular homogeneity, and markedly enhances fiber mechanical strength. These findings highlight that spiders employ diverse strategies to produce silk with exceptional mechanical properties. The spacer domain offers a way to enhance the properties of recombinant spider silk‐like fibers and other functional materials. [ABSTRACT FROM AUTHOR]

Six members of the 1,ω-bis(4-cyanobiphenyl-4′-yl) alkanes are reported and referred to as CBnCB in which n = 1, 15, 16, 17, 19 and 20 and indicates the number of methylene units in the spacer separating the two cyanobiphenyl units. The behaviour of CB3CB is revisited. The temperature dependence of the refractive indices, optical birefringence and dielectric permittivities measured in the nematic, N, phase for selected homologues are reported. The dimers with n ≥ 15 showed an enantiotropic N phase, and for the odd members the twist-bend nematic, NTB, phase was observed. CB3CB shows a direct NTB-isotropic, I, transition, whereas for CB1CB a virtual NTB-I transition is found. The temperature dependence of the bend elastic constant, K33, measured in the oblique helicoidal cholesteric state formed by mixtures of CBnCB with a chiral additive S811, shows strong non-monotonous behaviour with a deep minimum near the transition point to the NTB phase. The minimum value of ${K_{33}}$ K 33 decreases as n increases. The long even members of the CBnCB series show similar values of TNI to their odd-membered counterparts, but their estimated values of TNTBN are considerably lower. This is attributed to molecular shape and its effect on K33. [ABSTRACT FROM AUTHOR]

The symmetry of the flexion and extension gap influences the functional and long-term outcome after total knee arthroplasty (TKA). Most surgeons check it by applying varus and valgus stress using spacers. This technique has limited accuracy and could be easily extended by rotational movement of the spacer. The objective was to determine the detection threshold and interobserver reliability of this technique. In an in vitro setting with a human cadaveric knee, gap asymmetries were simulated by different medially and laterally applied forces. Using an optical measurement system, the pivot point of the spacer was calculated as a function of the gap symmetry in the first part of the experiment. In the second part, the detection threshold and interobserver reliability of 4 surgeons were determined. For this purpose, gap asymmetries were adjusted to between 0 and 120N in a blinded trial. With a symmetrical gap, the centre of rotation of the spacer was located in the centre of the tibia. With increasing gap asymmetry, the centre of rotation of the spacer shifted to the tight side. This shift was approximately linearly dependent on the force difference. A perfectly balanced gap was detected by the examiners in 50% of the cases. From a force difference of 40N, all examiners identified the gap asymmetry in all cases (ICC = 1.0). The method of spacer rotation described is suitable for reliably detecting gap differences at ≥ 40N, independently of the examiner. [ABSTRACT FROM AUTHOR]

To effectively suppress the violent galloping of the catenary additional wires in the strong wind section of high-speed railways, the anti-galloping effectiveness and anti-galloping mechanism of the spacer installed on the catenary additional wires are studied. Firstly, the finite element model of the additional wires of the catenary before and after the installation of the spacer is established. Secondly, the random wind field at the additional wires is simulated by the harmonic synthesis method (WAWS). Finally, the galloping response of the additional wires before and after the installation of the spacer is studied by using the finite element software. The results show that the installation of a single spacer at the midpoint of the span can reduce the vertical amplitude of the AF (Additional Feeder) and the PW (Protection Wire) by more than 39.80% and 41.51%, respectively, and the lateral amplitude decreases by more than 16.55% and 38.30%, respectively. The tension of the AF is greatly reduced, while the tension of the PW is slightly increased, so that the galloping of the AF and the PW tends to be synchronized. With the increase in the number of spacers installed, the anti-galloping effect continues to increase. At the same time, the anti-galloping mechanism of the spacer rod to suppress the vibration of the additional wires through the traction effect is clarified, and the effectiveness of the spacer rod in the anti-galloping of the additional wires of the catenary is proved. [ABSTRACT FROM AUTHOR]

Background: The gold standard treatment for periprosthetic joint infections is the two-stage revision that includes the spacer placement before definitive reimplantation. The management of PJI affects patients' joint function and, subsequently, their mental health. Even though significant advances have been achieved, little to no attention has been paid to the psychological implications. So, based on standardized patient-reported outcome measures (PROMs), this study aimed to clarify the effect of spacer treatment of infected hip and knee arthroplasties on patients' mental health. Methods: We performed research on the literature on PJIs in the English language using the MEDLINE database with the search strings "spacer" OR "spacers" AND "hip" OR "knee" AND "SF-12" OR "SF-36" OR "EQ-5" OR "mental" OR "depression" OR "anxiety." The reference lists of selected articles were also hand-searched for any additional articles. Results: A total of 973 published papers were extracted, and 9 papers were finally included. A total of 384 patients who underwent spacer placement for PJI were identified. Of these 384 patients, 54% were female. The mean age ranged from 62 to 78.2 years. Of the11 papers identified for this review, 4 analyzed only hip spacers, including 119 patients; 4 only knee spacers, evaluating 153 patients; while a single study included 112 patients for both joints. Conclusions: Patients with the spacer are living in a state of mental upset, albeit better than the preoperative state. Clinical improvement with the review is not assured. The alteration of mental state turns out not to be transient for all the patients. [ABSTRACT FROM AUTHOR]

Background. Klebsiella pneumoniae belongs to a group of opportunistic bacteria that can form multiple resistance to antibiotics and transmit it to various types of bacteria through horizontal gene transfer. These studies examine the structural and functional diversity of CRISPR/Cas systems that protect bacteria from foreign DNA. Their analysis using the example of antibiotic-resistant strains of Klebsiella pneumoniae will demonstrate their resistance to certain bacteriophages, which will make it possible to develop approaches to the treatment of complex infectious diseases caused by these microorganisms by creating targeted phage therapy.The aim. To perform a bioinformatics analysis of the identified structural components of CRISPR/Cas systems for screening bacteriophages through CRISPR cassette spacers using the example of antibiotic-resistant strains of Klebsiella pneumoniae.Materials and methods. The article analyzed 29 full-genome sequences of Klebsiella pneumoniae, in the genome of which the structures of CRISPR/Cas systems and antibiotic resistance genes were determined (according to NCBI). To achieve this goal, using software modeling methods, a search was made for Cas genes and CRISPR cassettes, and their structural and functional characteristics were given.Results. Using bioinformatic search algorithms in the genome of antibiotic-resistant strains, functionally active CRISPR/Cas systems with the presence of one or two CRISPR cassettes and belonging to Type I Subtype IE were identified. Groups of resistant strains with identical spacer composition of CRISPR cassettes have been identified. A phylogenetic analysis was carried out confirming their common origin. By analyzing the spacer sequences of CRISPR cassettes, the spectrum of diversity of phages of bacteria of the genus Klebsiella, Salmonella, belonging to the same family Enterobacteriaceae, was determined. Thus, information was obtained about the bacteriophages that are targeted by the action of CRISPR systems of Klebsiella pneumoniae strains that have antibiotic resistance.Conclusions. Analysis of the functional and structural features of the CRISPR/Cas systems of antibiotic resistant Klebsiella pneumoniae strains made it possible to obtain information about their evolutionary history and about the bacteriophages against which their action is directed, that is, about their phage resistance. The approach used in this study may further serve as the basis for the creation of personalized phage therapy

The objective is to minimize the inaccuracies in two-step impressions by homogenizing the polymerization shrinkage of elastomeric impression material in fixed prosthesis fabrication. The objective is accomplished by the technique of spacer adaptation and custom tray fabrication for two-step impressions. The technique makes the use of two vacuum-adapted spacers, selected based on the viscosity of elastomeric impression, and a vacuum-adapted custom tray. The procedure of using the specially fabricated custom tray for impression making is also presented. Consistent thickness of the two different viscosities of impression material is maintained due to vacuum adaptation of the spacers. This homogenizes the polymerization shrinkage of the elastomeric material in different regions of impression, as uniform space is occupied by the material in the space created by the spacer. The procedure of vacuum adaption of the tray material also limits the dimensional change of the tray. The technique minimizes the inaccuracies of impression by homogenizing the polymerization shrinkage of the elastomeric impression, thus promising a well-fitting prosthesis. [ABSTRACT FROM AUTHOR]

L'objectif de cette mise au point était de rapporter les modalités/indications de la radiothérapie (RT) stéréotaxique dans le cancer de la prostate (CaP) localisé, ainsi que d'expliquer le rôle de l'urologue dans cette préparation à l'irradiation. Une recherche sur la base de données PubMed et un examen narratif des articles ont été effectués en Décembre 2023 afin de proposer une revue compréhensive de la littérature sur le sujet. Seuls les articles en français ou en anglais ont été examinés. La RT stéréotaxique, ou en conditions d'hypofractionnement extrême, délivre généralement 35–40 Gy en 5 séances, guidée par l'image et en modulation d'intensité. Dans le traitement primaire du CaP localisé, la RT stéréotaxique est indiquée chez les patients à risque faible ou intermédiaire favorable, sans association à une hormonothérapie, chez des patients sélectionnés et dans des centres experts, selon les données d'efficacité de l'essai HYPO-RT-PC, et des données de sécurité de l'essai PACE-B. Dans le traitement de rattrapage après traitement primaire non chirurgical, la (ré)-irradiation stéréotaxique semblerait apporter des résultats oncologiques similaires aux autres modalités de traitement. Récemment, l'essai de phase I du GETUG-31 a comparé 2 schémas de RT stéréotaxique et rapportés des résultats encourageants dans cette indication. Le rôle de l'urologue est primordial avant RT stéréotaxique et une description de la préparation consistant en la mise en place de fiduciaires et de Spacer est proposée (https://www.urofrance.org/formation/pose-de-fiduciaires-et-spacer-par-voie-transperineale/) La RT stéréotaxique du CaP localisé est une thérapie aux indications croissantes, ou la collaboration urologue-radiothérapeute est primordiale. The aim was to report the modalities/indications of stereotactic body radiotherapy (SBRT) in localized prostate cancer (PCa) and to explain the role of the urologist in preparing for irradiation. A PubMed database search and narrative review of articles was performed in December 2023 to provide a comprehensive review of the literature on the subject. Only articles in French or English were examined. SBRT generally delivers 35-40 Gy over 5 sessions, image-guided and intensity-modulated. In the primary treatment of localized CaP, SBRT is indicated in patients at low or favorable intermediate risk, without combination with androgen deprivation therapy, in selected patients and in expert centers, based on efficacy data from the HYPO-RT-PC trial, and safety data from the PACE-B trial. Stereotactic (re)irradiation would appear to provide similar oncological results to other treatment modalities, in the case of salvage treatment after primary non-surgical treatment. The results of the GETUG-31 trial are encouraging, but larger comparative studies are still needed to clarify the place of SBRT in this indication. The role of the urologist is paramount prior to SBRT, and a description of the preparation consisting in the placement of gold markers and Spacer is proposed (https://www.urofrance.org/formation/pose-de-fiduciaires-et-spacer-par-voie-transperineale/) SBRT in localized CaP is a therapy with growing indications, where urologist-radiotherapist collaboration is crucial. [ABSTRACT FROM AUTHOR]

Purpose: Three-dimensional (3D) printed patient-specific instruments (PSI) have been introduced to increase precision and simplify surgical procedures. Initial results in femoral and tibial osteotomies are promising, but validation studies on 3D planning, manufacturing of patient-specific cutting blocks and 3D evaluation of the attained results are lacking. Methods: In this study, patient-specific cutting blocks and spacers were designed, fabricated, and used to perform a high tibial osteotomy (HTO). After segmentation of CT data sets from 13 human tibiae, 3D digital planning of the HTO was performed with a medial opening of 8 mm. These 3D models were used to fabricate patient-specific cutting blocks and spacers. After the surgical procedure, accuracy was evaluated measuring 3D joint angles and surface deviations. Results: The lowest mean deviation was found to be 0.57° (SD ± 0.27) for the MPTA. Medial and lateral tibial slope deviated from the 3D planning by an average of 0.98° (SD ± 0.53) and 1.26° (SD ± 0.79), respectively, while tibial torsion deviated by an average of 5.74° (SD ± 3.24). Color analysis of surface deviations showed excellent and good agreement in 7 tibiae. Conclusion: With 3D cutting blocks and spacers, the 3D planning of the HTO can be translated into reality with small deviations of the resulting joint angles. Within this study, the results of the individual steps are examined for errors and thus a critical evaluation of this new and promising method for performing patient-specific HTOs is presented. [ABSTRACT FROM AUTHOR]

Adequate substance exchange is an important prerequisite for tissue repair, and how to efficiently establish mature vascular networks to enhance the graft-host substance exchange is a challenge. Herein, inspired by the special structure of the aquatic plant “Ludwigia sedioides”, ultra-thin microporous scaffolds (TMS) of bovine Achilles tendon derived collagen were fabricated as “floating leaves” via pyridine reaction, and cleverly combined with platelet-rich plasma (PRP) after the Schiff base and Michael additions reactions of polydopamine to construct a biomimetic “Ludwigia sedioides” spacer (PTMS@P), allowing blood vessels (as a “rhizome”) freely shuttling and substance exchange. In this spacer, growth factors were efficiently released to peak concentrations in the first 12 h, thereby facilitating rapid blood vessel growth. In the subsequent 96 h, these slow-released growth factors retained at 11.6 % to 45.8 % of the peak concentrations, sustainedly promoting vascular networks shuttling through the spacer, graft-host substance exchange and extracellular matrix synthesis in fibroblasts. In vitro, the spacer significantly fostered fibroblasts and endothelial cells’ proliferation, adhesion and migration, which were fundamental for revascularization and substance exchange. Immunohistochemical staining of CD31 and Ki67 in vivo demonstrated that abundant vascular networks shuttled through PTMS@P and extended from flap base to the farther flap body, promoting more robust substance exchange and cellular metabolism, which significantly enhanced the survival of ischemic flaps in nude mice. Altogether, this “Ludwigia sedioides” inspired spacer PTMS@P with strengthened revascularization and substance-exchange functionality holds promising applications for tissue repair and regeneration.

Small balsam ( Impatiens parviflora DC.), an invasive plant native to central Asia, is currently one of the most extensive invasive plants in Central Europe, including Poland. Its expansion may affect populations of native species, such as touch-me-not balsam (Impatiens noli-tangere). It is particularly dangerous in legally protected areas, where the possibilities of eradicating it are very limited. There is some hope for stopping its expansion by using pathogens as a biological weapon. In this case, useful may be host-specific rust fungus Puccinia komarovii var. komarovii . Our three-year observations of I. parviflora infection severity by P. komarovii var. komarovii carried out in Poland in Drawa National Park (DNP) and Wigry National Park (WNP) showed the higher incidence of rust on leaves in DNP, where the median blade infestation for two years was 51% of leaf coverage. In contrast, for three years in WNP, the median blade infestation amounted to only 25%. The most severe symptoms occurred during the summer months. However the percentage of leaf coverage by pathogen exhibited fluctuations depending on the year, implying an influence of environmental conditions that stabilized the infection each season. Molecular analyses, in addition to confirming the infection of the tested plants by P. komarovii var. komarovii , enabled the characterization of its population based on comparative analysis of ITS and LSU sequences. Clear differences were found between the studied isolates and P. komarovii from I. glanduliferae and I. brachycentra . There was no diversity among our isolates, but they differed from the sequences of Polish isolates originating from I. parviflora available in GenBank, which indicates some diversity of rust in a relatively small area. It probably results from sexual reproduction and may enable rapid adaptation of the pathogen to the region or host plant, or it may indicate certain “entry points” to Poland, where the isolates arrived from their native place of occurrence.

Abstract Background Radial head arthroplasty is a viable option in cases with terrible triad injuries of elbow, wherein the radial head sustains significant comminution that precludes reconstruction. Nevertheless, this alternative is not recommended for individuals with poor elbow skin conditions, accompanied neuropsychiatric disorders, or low patient compliance. This case report presents a patient with bilateral terrible triad injury, along with the aforementioned conditions. The report outlines the treatment challenges of such a case and proposes potential solutions. Case presentation A 37-year-old Persian male patient presenting with a bilateral terrible triad fracture–dislocation and a history of psychoactive substance abuse, was admitted to our emergency department. The patient underwent radial head replacement using a cement spacer containing antibiotics, due to the comminuted radial head in the presence of a contaminated wound on the left elbow. The fracture of the right side was successfully fixed. Subsequent to discharge, the patient did not attend any follow-up appointments. After a period of 6 months, he was admitted to the psychiatric ward and orthopedic consultation was requested to evaluate the patient. Conclusion In acute terrible triad injuries with unreconstructable radial head fractures where arthroplasty with metallic prostheses may not be suitable due to contaminated wounds, unstable psychiatric condition, and low patient cooperation, temporary orthopedic cement spacers can maintain elbow biomechanics, stability, and sterility.

This paper presents an investigation of the oxidation of Alloy X-750 containing 5 wt% iron in a simulated boiling water reactor (BWR) environment. The specimens were exposed by a water jet (10 m/s) at 286 °C for durations ranging from 2 to 840 h, and the development of the oxide microstructure was mainly studied using electron microscopy. The results showed that the oxide scale consists of blocky crystals of trevorite on top of a porous inner layer rich in Ni and Cr. After the longest exposure time, the trevorite crystals completely covered the specimen surface. The study further revealed that the rate at which the oxide grew and the metal dissolved both decreased with time, and the metal thinning process appeared to be sub-parabolic. Given the significant variation in iron content in the X-750 specification, the influence of this element on the material’s corrosion performance in BWR was examined by comparing the results from this investigation with those from previous work on material containing 8 wt% Fe. The study demonstrates that the oxide growth, metal dissolution and metal thinning were slower in the material with a higher iron content, indicating the importance of this element in limiting the degradation of Alloy X-750 in BWR environments.

Background: The graft material generally used in superior capsular reconstruction (SCR) may be a human dermal allograft or an autologous tensor fascia lata (TFL) graft. According to a previous biomechanical study, a dermal graft (3 mm) was found to be insufficient and a thicker and stiffer graft was required. However, graft-site mobility should be considered when harvesting TFL, especially in the elderly. We have used Teflon felt as a graft material for SCR in the elderly for pain relief. This study aimed to compare the pain-relieving effects and clinical outcomes between Teflon felt and TFL graft. Methods: This study included 39 patients (Teflon felt group: 19 patients, TFL group: 20 patients) who underwent SCR with a minimum of 2-year follow-up. Patients with painful irreparable rotator cuff tears but with shoulder elevation (abduction or flexion) of at least 130° were included in the study. Shoulder range of motion, acromiohumeral distance, and the numerical rating scale were evaluated preoperatively and 2 years postoperatively. Results: There were no significant differences between the Teflon felt and TFL groups in terms of shoulder elevation (151 ± 33° vs. 164 ± 15°, P = .57), acromiohumeral distance (8.3 ± 2.2 mm vs. 7.5 ± 2.5 mm, P = .14), and numerical rating scale (1.0 ± 1.2 vs. 0.9 ± 0.8, P = .93). Conclusion: SCR with Teflon graft provided pain relief equivalent to TFL graft. It may be an effective treatment option in elderly patients for irreparable rotator cuff tears with respect to pain relief.

Introduction: Anterior cervical discectomy and fusion (ACDF) is commonly performed with cage and plate constructs to stabilise diseased or injured cervical segments. Despite it being a commonly performed procedure, there are notable rates of associated morbidity reported in the literature. Stand-alone spacers represent a novel form of instrumentation to conventional cage and plate constructs. Research question: Do stand-alone spacers have improved operative characteristics and postoperative outcomes in ACDF cohorts when compared to cage and plate constructs? Methods: A systematic review and meta-analysis was conducted of PubMed/Medline, Embase and Google Scholar databases per the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes guidelines. Studies of interest included cage and plate instrumentation versus anchored stand-alone spacers for patients undergoing ACDF. Pre- and post-operative clinical and radiological outcomes were collated and compared for significance between cohorts. Results: 10 RCTs were identified and included with 779 patients total. Mean age of the entire cohort was 50.1 years. 62% (483/779) of the cohort were male. 384 patients underwent ACDF with stand-alone cage, while 395 had ACDF with conventional cage and plate. Stand-alone spacers significantly outperformed conventional instrumentation in terms of estimated blood loss (p

One of the most important adaptive immune systems in bacteria against phages is clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPRassociated (CAS) genes. In this investigation, an approach based on genome mining was employed to characterize the CRISPR-Cas systems of Lacticaseibacillus rhamnosus strains. The analysis involved retrieving complete genome sequences of L. rhamnosus strains, and assessing the diversity, prevalence, and evolution of their CRISPR-Cas systems. Following this, an analysis of homology in spacer sequences from identified CRISPR arrays was carried out to investigate and characterize the range of target phages. The findings revealed that 106 strains possessed valid CRISPR-Cas structures (comprising CRISPR loci and Cas genes), constituting 45% of the examined L. rhamnosus strains. The diversity observed in the CRISPR-Cas systems indicated that all identified systems belonged to subtype II-A. Analyzing the homology of spacer sequences with phage and prophage genomes discovered that strains possessing only CRISPR-Cas subtype II targeted a broader spectrum of foreign phages. In summary, this study suggests that while there is not significant diversity among the CRISPR-Cas systems identified in L. rhamnosus strains, there exists notable variation in subtype II-A systems between L. rhamnosus and other lactobacilli. The diverse nature of these CRISPR-Cas systems underscores their natural activity and importance in adaptive immunity. [ABSTRACT FROM AUTHOR]

Three new thiourea-based thermo-reversible, low molecular weight organogelators (LMOGs) 3-5 have been synthesized using (+)-Dehydroabietylamine (DAA, a tricyclic diterpene) employing DLS (Diterpene-Linker-spacer) strategy. (+) DAA was converted into isothiocynates through a cascade of reactions and cross-coupled with primary amines to furnish thiourea 3-5 with respective spacers. The structures of gelators 3-5 were confirmed through 1H-NMR and 13C-NMR spectroscopy, high-resolution electron spray ionization mass spectrometry (HRESI–MS, positive mode) and FTIR spectroscopy. Gelation potential of gelators 3-5 was investigated through inverted test tube method and sol–gel transition measured by ball-dropping method. The results revealed that unbranched alkyl groups furnish gelation and their gelation ability increases with increasing spacer length. Gelator 5 with dodecyl chain found to be excellent gelator that can gelate hexane (spontaneously), toluene, methanol, ethanol, petrol, and diesel. Morphology of gels was studied though scanning electron microscopy exhibiting fibrillar to lamellar structure with a thickness in the range of 9.5 nm to 5.0 μm with increasing length of spacer. [ABSTRACT FROM AUTHOR]

Background: Radial head arthroplasty is a viable option in cases with terrible triad injuries of elbow, wherein the radial head sustains significant comminution that precludes reconstruction. Nevertheless, this alternative is not recommended for individuals with poor elbow skin conditions, accompanied neuropsychiatric disorders, or low patient compliance. This case report presents a patient with bilateral terrible triad injury, along with the aforementioned conditions. The report outlines the treatment challenges of such a case and proposes potential solutions. Case presentation: A 37-year-old Persian male patient presenting with a bilateral terrible triad fracture–dislocation and a history of psychoactive substance abuse, was admitted to our emergency department. The patient underwent radial head replacement using a cement spacer containing antibiotics, due to the comminuted radial head in the presence of a contaminated wound on the left elbow. The fracture of the right side was successfully fixed. Subsequent to discharge, the patient did not attend any follow-up appointments. After a period of 6 months, he was admitted to the psychiatric ward and orthopedic consultation was requested to evaluate the patient. Conclusion: In acute terrible triad injuries with unreconstructable radial head fractures where arthroplasty with metallic prostheses may not be suitable due to contaminated wounds, unstable psychiatric condition, and low patient cooperation, temporary orthopedic cement spacers can maintain elbow biomechanics, stability, and sterility. [ABSTRACT FROM AUTHOR]

Mixing in gas separation membranes has received much less attention than in membrane liquid separation because gas molecules have much smaller viscosity, allowing them to diffuse easily through membranes without requiring significant flow mixing. However, due to advancements in membrane fabrication technologies aimed at improving material properties, concentration polarization (CP) might become an issue in gas separation due to enhanced membrane efficiency and permeability. Consequently, a 2D CFD analysis is conducted to evaluate the impact of spacer-induced mixing on membrane gas concentration polarization for typical CO 2 /CH 4 gas separation. Results show that spacers generally enhance flux performance while reducing CP in the membrane channel when compared to the case without spacers. Furthermore, the effectiveness of spacer-flux-to-pressure-loss-ratio (SPFP) reaches a peak for a Reynolds number in the range of 5 < Re h < 200 because of the trade-off between flux and pressure drop. This mixing-induced flux enhancement is most effective under high CP conditions (less mixing) within the membrane channel. Similarly, flux enhancement due to spacers can be observed as membrane selectivity, pressure ratio and feed gas concentration increase due to enhanced CP. [Display omitted] • 2D CFD analysis of the impact of spacer-induced mixing on membrane gas separation. • The spacer-flux-to-pressure-loss-ratio reaches a peak at 5 < Re h < 200. • Spacer reduces CP and enhances gas permeation flux compared with empty channel. • Spacer is most effective in enhancing gas permeate flux under high CP conditions. • Spacer enhances flux as selectivity, pressure ratio and feed concentration increase. [ABSTRACT FROM AUTHOR]

Background: Biodegradable subacromial balloon spacers (SBSs) have become increasingly used for the treatment of massive irreparable rotator cuff tears given their theorized clinical benefits; however, the relationship between biomechanical functions of the balloon spacer and clinical benefits remains unclear. Purpose: To perform a systematic review and meta-analysis of controlled laboratory studies investigating the use of SBSs for massive irreparable rotator cuff tears. Study Design: Systematic review and meta-analysis; Level of evidence, 4. Methods: PubMed, OVID/Medline, and Cochrane databases were queried in July 2022 for biomechanical data pertaining to SBS implantation in cadaveric models of irreparable rotator cuff tears. Random-effects meta-analysis of continuous outcomes using the DerSimonian-Laird method was performed to estimate pooled-treatment effect sizes between the irreparable rotator cuff tear state and the state in which an SBS was implanted. Data reported variably or in formats not amenable to analysis were presented descriptively. Results: Five studies involving 44 cadaveric specimens were included. At 0° of shoulder abduction, SBS implantation resulted in a mean inferior humeral head translation of 4.80 mm (95% CI, 3.20-6.40; P <.001) relative to the irreparable rotator cuff tear state. This decreased to 4.39 mm and 4.35 mm at 30° and 60° of abduction, respectively. At 0° of abduction, implantation of an SBS was associated with a 5.01-mm (95% CI, 3.56-6.46, P <.001) anterior translation of the glenohumeral center of contact pressure relative to the irreparable tear state. This translation changed to 5.11 mm and 5.49 mm at 30° and 60° of abduction. In 2 studies, SBS implantation restored the glenohumeral contact pressure to that of the intact state and significantly reduced subacromial pressure distribution over a rotator cuff repair state. In 1 study, a high balloon fill volume (40 mL) resulted in a significant 10.3 ± 1.4–mm more anterior humeral head position relative to the intact cuff state. Conclusion: SBS implantation in cadaveric models of irreparable rotator cuff tears results in significant improvements in humeral head position at 0°, 30°, and 60° of shoulder abduction. Balloon spacers may also improve glenohumeral and subacromial contact pressures, although insufficient evidence currently exists to corroborate these findings. High balloon fill volumes (40 mL) may confer supraphysiologic anteroinferior translation of the humeral head. [ABSTRACT FROM AUTHOR]

This study reports the effects of the grid spacer with mixing vane (MV) on gas velocity for air single-phase flow and liquid film thickness for air-water two-phase annular flow in a 3 × 3 rod bundle channel. To investigate the effects of the shape of the spacers, three kinds of spacers were installed into the channel: spacer without MV (without MV), spacer with four MVs (4-MV30), and spacer with two MVs (2-MV30). The 4-MV30 and 2-MV30 had vanes that were inclined 30 deg from the vertical axis. Gas velocity was measured with a hot-wire anemometer and liquid film thickness was measured with the constant electric current method. From the gas velocity measurement, it was found that the irregularities in the velocity distribution became smaller toward downstream of the spacer. For the 2-MV30, the flow distribution was asymmetric and the flow was biased. From the liquid film thickness measurement, it was found that the liquid film thickness became thicker downstream of the spacer. [ABSTRACT FROM AUTHOR]

This paper presents an investigation of the oxidation of Alloy X-750 containing 5 wt% iron in a simulated boiling water reactor (BWR) environment. The specimens were exposed by a water jet (10 m/s) at 286 °C for durations ranging from 2 to 840 h, and the development of the oxide microstructure was mainly studied using electron microscopy. The results showed that the oxide scale consists of blocky crystals of trevorite on top of a porous inner layer rich in Ni and Cr. After the longest exposure time, the trevorite crystals completely covered the specimen surface. The study further revealed that the rate at which the oxide grew and the metal dissolved both decreased with time, and the metal thinning process appeared to be sub-parabolic. Given the significant variation in iron content in the X-750 specification, the influence of this element on the material's corrosion performance in BWR was examined by comparing the results from this investigation with those from previous work on material containing 8 wt% Fe. The study demonstrates that the oxide growth, metal dissolution and metal thinning were slower in the material with a higher iron content, indicating the importance of this element in limiting the degradation of Alloy X-750 in BWR environments. [ABSTRACT FROM AUTHOR]

Copyright of China Surfactant Detergent & Cosmetics (2097-2806) is the property of China Surfactant Detergent & Cosmetics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Zeitschrift für Rheumatologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the course of this research, we successfully created three series of liquid crystalline compounds featuring the trans-cyclohexane structure. One series of compounds featured a double bond at the terminal position of the molecules, whereas the remaining two series incorporated disiloxane and trisiloxane groups. Each series comprised five spacers of different lengths, specifically 3, 4, 5, 6, and 11 methylene units. We identified the structures of the synthesized compounds using Nuclear Magnetic Resonance spectroscopy and characterized their liquid crystalline behavior through thermal analysis and polarized optical microscopy. The results revealed that both the length of the spacer and the presence of siloxane groups significantly influenced the liquid crystal phase transitions, transition temperatures, and temperature ranges. These findings provide valuable insights for designing and developing new liquid crystal materials with tailored properties for various applications. [ABSTRACT FROM AUTHOR]

Plastic spacers create a linear and systemic weakening of the structure. The extreme loading of the structure tests the structure itself to its load-bearing limit or even locally exceeds this limit, thus revealing all its weak points, which are the spacers. Nevertheless, the influence of the spacers is not included in the design calculation of the reinforced concrete element. In addition, products intended as spacers for the placement of reinforcement do not belong to the specific families of construction products covered by a harmonized standard of European parliament regulation. For these reasons, it is not required to demonstrate any characteristics of these products. This fact allows the use of arbitrary spacers' shapes and materials. As shown by the experiment carried out, the use of commonly used plastic liners will result in a weakening of the cross-section. The normal assessment of the ultimate or serviceability limit state is not affected by this weakening. An example of an experiment carried out where this problem was captured is the subject of this paper. With Europe's current deteriorated safety situation, understanding the influence of spacers in blast-loaded reinforced concrete structures on structural failure is important, and it is appropriate to further address this issue. Based on this experiment, it is not possible to accurately identify the causes of the explosion cracks. In order to determine with certainty the effect of spacers on the strength of the structure under abnormal blast loadings, research needs to focus on this area. In the field experimental measurements and numerical simulations, it was found that the use of linear spacers has an effect on crack formation under the blast action of the tested slab. [ABSTRACT FROM AUTHOR]

Purpose: Antibiotic loaded bone cement spacers provide high local antibiotic concentrations, preserve bone stock, and reduce soft tissue contractions. The objective of this in-vitro study was to compare antibiotic release from spacers, aiming to discover the most optimal preparation and identify modifiable factors that can further enhance antibiotic release. Methods: Six distinct spacer preparation were created using three different bone cements and manual incorporation of antibiotics. During a six-week period, the release of antibiotics from each spacer was measured individually at ten predetermined time points using a chemiluminescent immunoassay. Results: Manually adding 4 g of vancomycin to every 40 g of "Palacos R + G" yielded the most favorable release profile. Throughout all preparations, antibiotic release consistently and significantly decreased over the six-week period. When incorporating a higher concentration of vancomycin, a significantly higher cumulative release of vancomycin was observed, with varying effects on the release of gentamicin. The choice of bone cement had a significant impact on antibiotic release. Conclusion: To enhance antibiotic release from spacers, surgeons should manually incorporate high antibiotic concentrations into the most appropriate bone cement and keep the interim period as short as possible. Specifically, we suggest manual incorporation of 4 g of vancomycin to every 40 g of gentamicin premixed "Palacos R + G" to create bone cement spacers. [ABSTRACT FROM AUTHOR]

The management of periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) has considerable variation. In order to better capture current preferences for the management of PJI, this study sought to poll the current members of American Association of Hip and Knee Surgeons (AAHKS) first to characterize the distribution of practice patterns. There were 32 questions in an online survey distributed to members of AAHKS. The questions were multiple choice regarding the management of PJI for TKA. There were 844 out of 2,752 members who completed the survey (response rate of 31%). Most of the members were in private practice (50%) compared to 28% being in an academic setting. On average, members were performing between 6 to 20 PJI cases per year. Two-stage exchange arthroplasty was performed in over 75% of the cases with either a cruciate retaining (CR) or posterior stabilized (PS) primary femoral component used in over 50% of the cases and 62% using an all-polyethylene tibial implant. Most of the members were using vancomycin and tobramycin. Typically, 2 to 3 grams of antibiotics were added per bag of cement regardless of the cement type. When indicated, amphotericin was the most often-used antifungal. Post-operative management had major variability with range of motion, brace use, and weight-bearing restrictions. There was variability in the responses from the members of AAHKS, but there was a preference toward performing a two-stage exchange arthroplasty with an articulating spacer using a metal femoral component and an all-polyethylene liner. [ABSTRACT FROM AUTHOR]

Abstract Background and objective At present, the influence of the internal metallic endoskeleton of Spacer on the biomechanical strength of Spacer remains unclear. The aim of this study was to analyze the mechanical stability of a novel Spacer applying a annular skeleton that mimics the structure of trabecular bone using finite element methods. Metheds The femur models of three healthy individuals and skeletonless Spacer, K-Spacer, and AD-Spacer were assembled to create 15 3D models. Finite element analysis was performed in an Ansys Bench2022R1. Biomechanical parameters such as stress and strain of the Spacer, internal skeleton and femur were evaluated under three loads, which were applied with the maximum force borne by the hip joint (2100 N), standing on one leg (700 N), and standing on two legs (350 N). The mechanical properties of the new hip Spacer were evaluated. Result The stresses on the medial and lateral surfaces of the AD-Spacer and K-Spacer were smaller than the stresses in the state without skeletal support. The maximum stresses on the medial and lateral surfaces of the AD-Spacer were smaller than those of the inserted K-Spacer, and the difference gradually increased with the increase of force intensity. When the skeleton diameter was increased from 3 to 4 mm, the stresses in the medial and lateral sides of the AD-Spacer and K-Spacer necks decreased. The stress of both skeletons was concentrated at the neck, but the stress of the annular skeleton was evenly distributed on the medial and lateral sides of the skeleton. The mean stress in the proximal femur was higher in femurs with K-Spacer than in femurs with AD-Spacer. Conclusions AD-Spacer has lower stress and higher load-bearing capacity than K-Spacer, and the advantages of AD-Spacer are more obvious under the maximum load state of hip joint.

Background Periprosthetic infection develops in 0.5 to 5.0 % of cases after knee replacement, which is a social and economic problem. The most common causes of periprosthetic infection are methicillin-resistant staphylococcus aureus (MRSA) (36 %), gram-negative bacteria, and microbial associations. The study was aimed at improving the results of the sanitizing stage of revision arthroplasty in patients with periprosthetic infection of the knee joint by a developed long-acting antimicrobial composition and improving the designs of articulating spacers of the knee joint. Materials and Methods The treatment results of 121 patients with knee joint periprosthetic infection were analyzed. Nine patients had an early periprosthetic infection and 112 had a late one. Patients in satisfactory condition with stable implant components who had early periprosthetic infection underwent surgical treatment of the purulent focuses, replacement of a polyethylene tibial insert, thorough surgical wound washing using pulse lavage, drainage, and VAC-therapy. Patients with late periprosthetic infection were divided into 3 groups on the basis of the spacer used. An articulating spacer based on the developed antimicrobial composition of prolonged action (RU 191236 patent) was used in 59 patients of the first group. Preformed spacers were implanted in 29 patients of the second group, and 18 patients of the third group got a block-shaped spacer. Results An antibacterial anti-adhesive non-toxic composition with a prolonged action based on bone cement with gentamicin and such antiseptics as poviargol, dioxydine, and high-molecular polyvinylpyrrolidone has been developed. All the patients underwent the sanitizing stage of revision arthroplasty, implant removal, and spacer installation. Periprosthetic infection recurrence developed in 3 patients of the first group, 9 patients of the second group and 7 patients of the third one. The average time from the sanitizing stage to the second final stage of revision was 3-6 (4.8 ± 1.9) months. Discussion According to scientific data, the impregnation of new antibiotics into bone cement with gentamicin does not improve the antimicrobial effect of a spacer, especially in case of antibiotic-resistant strains. Block-shaped and preformed spacers lead to infection recurrence and complications. Antiseptic impregnation with different mechanisms of action is able to affect antibiotic-resistant bacteria, and the polymer is able to prolong the effect. Conclusion The use of articulating spacers for the knee joint, which include an antimicrobial composition, allows preserving the function of the joint and reducing the number of infectious complications, which facilitates the final stage of revision arthroplasty.

One of the most important adaptive immune systems in bacteria against phages is clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (CAS) genes. In this investigation, an approach based on genome mining was employed to characterize the CRISPR-Cas systems of Lacticaseibacillus rhamnosus strains. The analysis involved retrieving complete genome sequences of L. rhamnosus strains, and assessing the diversity, prevalence, and evolution of their CRISPR-Cas systems. Following this, an analysis of homology in spacer sequences from identified CRISPR arrays was carried out to investigate and characterize the range of target phages. The findings revealed that 106 strains possessed valid CRISPR-Cas structures (comprising CRISPR loci and Cas genes), constituting 45% of the examined L. rhamnosus strains. The diversity observed in the CRISPR-Cas systems indicated that all identified systems belonged to subtype II-A. Analyzing the homology of spacer sequences with phage and prophage genomes discovered that strains possessing only CRISPR-Cas subtype II targeted a broader spectrum of foreign phages. In summary, this study suggests that while there is not significant diversity among the CRISPR-Cas systems identified in L. rhamnosus strains, there exists notable variation in subtype II-A systems between L. rhamnosus and other lactobacilli. The diverse nature of these CRISPR-Cas systems underscores their natural activity and importance in adaptive immunity.