Bi-layer cBN-based composites reinforced with oxide and non-oxide microfibers of refractory compounds.

Research into new composites utilizing cubic boron nitride (PcBN) shows promise for enhancing cutting tool performance. The unique properties of these materials stem from the addition of microfibers made of refractory compounds to their structure. This study looks at developing two-layer composites based on cBN group BL, reinforced with SiCw and Al2O3w microfibers. The goal is to improve tool stability when cutting hardened steels with impact loads. PcBN composite samples were made by sintering a mixture of cBN powder with bundles and microfibers under 7.7 GPa pressure. Bond material selection was based on analyzing the relationship between Poisson's ratio (η) and plasticity parameter (G/B). The density, Young's modulus, Poisson's ratio, and hardness of the composites were determined, and the microstructure of samples with TiCN bond was studied. Tool-life tests were conducted on two-layer cutting inserts made of PcBN reinforced with SiCw and Al2O3w microfibers during the machining of hardened KhVG steel (HRC 55) under impact loads at cutting speeds of 100 and 200 m/min.

Influence of pallet rich plasma, quercetin and their combination on activity of nitric oxide cycle enzymes in nasal mucosa of patients with atrophic rhinitis.

OBJECTIVE: Aim: To study the general activity of NO synthases (gNOS), the activity of inducible and constitutive isoforms of NO synthase, the activity of arginases, and the concentration of nitrites in the nasal mucosa under the conditions of local treatment of chronic atrophic rhinitis (AR) with quercetin and platelet-rich plasma (PRP therapy).. PATIENTS AND METHODS: Materials and Methods: The study was conducted on 118 patients divided into two groups: control (n=20) and experimental (patients with AR, n=98). Experimental group was divided into 4 subgroups: standard treatment (n=29), PRP therapy (6 injections for 28 day course, n=19), Quercetin (40 mg 3 times a day for 28 days, n=26) and PRP+Quercetin (n=24) groups. RESULTS: Results: Standard therapy of SaR increases gNOS by 278.38% and arginase activity increases by 222.73%. PRP therapy increases gNOS by 211.43% and arginase by 540.91%. Quercetin elevates gNOS by 108.33% and arginase by 250%. PRP therapy and quercetin increases gNOS by 146.15% and arginase by 536.36%. CONCLUSION: Conclusions: The use of standard therapy of SaR and addition of PRP therapy, quercetin and their combination effectively restores the production of nitric oxide and the arginase activity in the nasal mucosa.

Robust, Narrow-Band Nanorods LEDs with Luminous Efficacy > 200 lm/W: Next-Generation of Efficient Solid-State Lighting.

Energy-efficient white light-emitting diodes (LEDs) are in high demand across the society. Despite the significant advancements in the modern lighting industry based on solid-state electronics and inorganic phosphor, solid-state lighting (SSL) continues to pursue improved efficiency, saturated color performance, and longer lifetime. Here in this article, robust, narrow emission band nanorods (NRs) are disclosed with tailored wavelengths, aiming to enhance the color rendering index (CRI) and luminous efficacy (LE). The fabricated lighting device consists of NRs of configuration CdSe/ZnxCd1-xS/ZnS, which can independently tune CRI R1-R9 values and maximize the luminous efficacy. For general lighting, NRs with quantum yield (QY) up to 96% and 99% are developed, resulting in ultra-efficient LEDs reaching a record high luminous efficacy of 214 lm W-1 (certified by the National Accreditation Service). Furthermore, NRs are deployed onto mid-power (0.3 W@ 50 mA) LEDs, showing significantly enhanced long-term stability (T95 = 400 h @ 50 mA). With these astonishing properties, the proposed NRs can pave the way for efficient lighting with desired optical spectrum.

NMR detection of the strained metallacycles in organolithiums: theoretical study.

For the first time through quantum chemistry methods, the effective use of 1JCLi spin-spin coupling constants as descriptors for assessing the formation of strained metallacycles is demonstrated. Both acyclic organolithiums and 3- to 7-membered metallacycles are examined. 80 organolithium compounds, including both monomeric and dimeric species, with ligands containing fluorine, nitrogen, oxygen, and carbon (in the form of carbanions), are tested. In general, the 1JCLi values below 12 Hz for monomeric species and below 6 Hz for dimeric species serve as clear indicators of strained monomeric metallacycle formation (for 6Li nuclei). The primary contributor to the overall 1JCLi value is the Fermi-contact term, which correlates directly with the carbon-lithium interatomic distance and allows to distinguish between dimers and monomers.

PREVALENCE OF AEROBIC VAGINITIS AFTER GYNECOLOGICAL SURGERIES AND ASSOCIATED ADVERSE PREGNANCY OUTCOME IN UKRAINE.

OBJECTIVE: Aim: To determine prevalence of Aerobic Vaginitis (AV) after gynecologic surgery, risk factors and antimicrobial resistance of responsible pathogens, and adverse pregnancy outcomes in Ukraine. PATIENTS AND METHODS: Materials and Methods: Multicenter retrospective cohort study was conducted from January 2020 to December 2022 in fifteen medical clinics from eight regions of Ukraine. Smears were analyzed using Donders' classification method and Dong's modified AV diagnosis for Gram stains. Definitions of HAIs were adapted from the CDC/NHSN. Antibiotic susceptibility testing of bacteria was determined by Kirby-Bauer disc diffusion test according to the protocol of the EUCAST. RESULTS: Results: Prevalence of AV among women's undergoing gynecologic surgery in Ukraine was 68.7%. Of the total AV cases, 70.3% were in non-pregnant and 29,7% in pregnant women. The most common pathogen of AV was Escherichia coli, followed by Enterococcus faecalis, Streptococcus agalactiae, Staphylococcus aureus, Enterococcus faecium, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Among the S. aureus strains, 11,6% of MRSA (Methicillin resistant S.aureus) were isolated whereas none of the CoNS were cefoxitin resistant. History of vaginal infection, history of post-operative infection and antibiotic use acted as an important risk factor of AV incidence rate. The presence of AV worsened pregnancy outcomes, by increasing the incidence of preterm birth, the premature rupture of membranes, miscarriage, neonatal jaundice, and neonatal infection. CONCLUSION: Conclusions: Aerobic Vaginitis after gynecological surgeries in Ukraine is a common medical problem in women that is associated with significant morbidity, adverse pregnancy outcome, and hence frequent medical visits.

HEALTHCARE-ASSOCIATED BACTERIAL VAGINOSIS AFTER GYNECOLOGICAL SURGERIES AND ASSOCIATED ADVERSE PREGNANCY OUTCOME IN UKRAINE.

OBJECTIVE: The aim: To determine the prevalence of healthcare-associated bacterial vaginosis after gynecological surgeries and associated adverse pregnancy outcomes in Ukraine. PATIENTS AND METHODS: Materials and methods: Multicenter retrospective cohort study was conducted from January 2019 to December 2021 in eleven medical centers from eight regions of Ukraine. Vaginal cultures were obtained preoperatively from 3,502 women undergoing gynecologic surgery. Diagnosis of Bacterial Vaginosis is based on the Nugent and Amsel criteria. RESULTS: Results: Healthcare-associated bacterial vaginosis (HA BV) was diagnosed in 1,498 of 3,502 women, giving a prevalence rate of 42.8%. HA BV was significantly associated with preterm birth (risk ratio [RR], 2.68; 95% confidence interval [CI], 1.44-4.98), miscarriage (RR, 6.11; 95% CI, 3.22-14.11), low birth weight (RR, 3.20; 95% CI, 1.29-7.94), and premature rupture of membranes (RR, 6.75; 95% CI, 3.11-14.67). CONCLUSION: Conclusions: The HA BV after gynecological surgeries prevalence is high in Ukraine, with a concomitant adverse pregnancy outcome, including preterm birth, low birth weight, premature rupture of membranes, and miscarriage. A significant number of cases of bacterial vaginosis are associated with long-term use of antibiotics to treat post-operative infections.

POSTOPERATIVE INFECTIONS AFTER GYNECOLOGICAL SURGERIES IN UKRAINE.

OBJECTIVE: Aim: To determine the current prevalence of surgical site infections (SSIs) after gynecological surgeries and antimicrobial resistance of causing pathogens in Ukraine. PATIENTS AND METHODS: Materials and Methods: Multicenter prospective observational cohort study was conducted from January 2020 to December 2022 in nine hospitals from eight regions of Ukraine. Definitions of HAIs were adapted from the Centers for Disease Control and Prevention's National Healthcare Safety Network. Antibiotic susceptibility was done by the disc diffusion test as recommended by EUCAST. RESULTS: Results: A total 12.2% (420/3450) patients who undergoing gynecological surgeries were found to have SSIs. The difference in SSI rates between the three subgroups by route of surgery was not statistically significant, being 12.0% for the abdominal group,11.1% for the vaginal group, and 12.5% for the combined group. The most common causing pathogens of SSIs was Escherichia coli, Pseudomonas aeruginosa, Enterobacter spp., Streptococcus spp., and Klebsiella pneumoniae. Many Gram-negative pathogens isolated from SSI cases were found to be multidrug resistant. CONCLUSION: Conclusions: This study showed that SSIs remains the common complication after gynecological procedures in Ukraine. Best practices should be established and followed to reduce the risk of SSIs associated with gynecologic surgery. Optimizing the antibiotic prophylaxis and empirical antimicrobial therapy may reduce the burden of SSIs in gynecological surgeries, but prevention is the key element.

Ultralow Roll-Off Quantum Dot Light-Emitting Diodes Using Engineered Carrier Injection Layer.

Quantum dot (QD) light-emitting diodes (QLEDs) have attracted extensive attention due to their high color purity, solution-processability, and high brightness. Due to extensive efforts, the external quantum efficiency (EQE) of QLEDs has approached the theoretical limit. However, because of the efficiency roll-off, the high EQE can only be achieved at relatively low luminance, hindering their application in high-brightness devices such as near-to-eye displays and lighting applications. Here, this article reports an ultralow roll-off QLED that is achieved by simultaneously blocking electron leakage and enhancing the hole injection, thereby shifting the recombination zone back to the emitting QDs layer. These devices maintain EQE over 20.6% up to 1000 mA cm-2 current density, dropping only by ≈5% from the peak EQE of 21.6%, which is the highest value ever reported for the bottom-emitting red QLEDs. Furthermore, the maximum luminance of the optimal device reaches 320 000 cd m-2 , 2.7 times higher than the control device (Lmax : 128 000 cd m-2 ). A passive matrix (PM) QLED display panel with high brightness based on the optimized device structure is also demonstrated. The proposed approach advances the potential of QLEDs to operate efficiently in high-brightness scenarios.

THE IMPORTANCE OF THE PROGNOSTIC SCORE FOR THE CHOICE OF CHIVA HEMODYNAMIC SURGERY AS A TREATMENT METHOD FOR VARICOSE VEINS OF THE LOWER EXTREMITIES.

OBJECTIVE: The aim: To work out the predictive system that can help to determine the group of patients to whom the hemodynamic surgery of varicose disease, CHIVA, is beneficial. PATIENTS AND METHODS: Materials and methods: Results of examination and treatment of 58 patients of the main group who underwent hemodynamic surgery and 65 patients of the comparison group who underwent stripping. Patients of both groups were evaluated in the preoperative period using an evaluation scale, and divided into three subgroups depending on the scores: 5- 8, 9 - 11, and 12 - 15 points. RESULTS: Results: The best treatment results with the lowest number of relapses were obtained in the subgroup of patients with low scores on the prognostic scale (5-8 points) after hemodynamic treatment and in the subgroup of patients with a high the number of points (12 -15 points) after the classic stripping (p < 0.05). The same subgroups received more improvement in the quality of life of patients according to CIVIQ 20 (p < 0.001). The subgroup of patients with a high number of points (12 -15 points) after the stripping received significantly more reduction in scores VCSS (p < 0,01). CONCLUSION: Conclusions: Comprehensive assessment of factors such as the anamnestic duration of the disease, the diameter of the great saphenous vein, the presence of skin complications, dilated varicose collaterals and previous surgical treatment using a prognostic preoperative assessment score allows the surgeon to be more clearly guided in choosing the optimal method of treatment for each patient and achieve the best treatment results.

Safety and immunogenicity of rAd26 and rAd5 vector-based heterologous prime-boost COVID-19 vaccine against SARS-CoV-2 in healthy adolescents: an open-label, non-randomized, multicenter, phase 1/2, dose-escalation study.

To protect young individuals against SARS-CoV-2 infection, we conducted an open-label, prospective, non-randomised dose-escalation Phase 1/2 clinical trial to evaluate the immunogenicity and safety of the prime-boost "Sputnik V" vaccine administered at 1/10 and 1/5 doses to adolescents aged 12-17 years. The study began with the vaccination of the older cohort (15-to-17-year-old participants) with the lower (1/10) dose of vaccine and then expanded to the whole group (12-to-17-year-old participants). Next, 1/5 dose was used according to the same scheme. Both doses were well tolerated by all age groups. No serious or severe adverse events were detected. Most of the solicited adverse reactions were mild. No significant differences in total frequencies of adverse events were registered between low and high doses in age-pooled groups (69.6% versus 66.7%). In contrast, the 1/5 dose induced significantly higher humoral and T cell-mediated immune responses than the 1/10 dose. The 1/5 vaccine dose elicited higher antigen-binding (both S and RBD-specific) as well as virus-neutralising antibody titres at the maximum of response (day 42), also resulting in a statistically significant difference at a distanced timepoint (day 180) compared to the 1/10 vaccine dose. Higher dose resulted in increased cross-neutralization of Delta and Omicron variants. Clinical Trial Registration: ClinicalTrials.gov, NCT04954092, LP-007632.

DEVELOPMENT OF COORDINATION ABILITIES IN 6-10 YEARS OLD BOYS WITH POSTURAL DISORDERS.

OBJECTIVE: The aim: To develop, substantiate and experimentally test the methodology for the development of coordination abilities in 6-10 years old boys with postural disorders during their physical education training sessions. PATIENTS AND METHODS: Materials and methods: The experimental (EG) and the control groups (CG) were formed to organize the pedagogical experiment. The EG included 17 boys and the CG consisted of 19 boys. The EG was engaged in sports activities according the developed methodology and the CG followed the current school curricula on physical education. RESULTS: Results: The methodology for the development of coordination abilities in 6-10 years old boys with postural disorders in the process of their physical education has been developed. Its peculiarity lies in the accentuated influence on the vestibular, motor and visual analyzers with the help of a system of exercises aimed at controlling movements in space in static positions and during movement. CONCLUSION: Conclusions: The obtained results testify to the effectiveness of the developed methodology. The EG boys had significantly higher indicators of static balance and coordination abilities at body position change, as well as general coordination of movements (p ≤ 0.05) at the end of the academic year than those of the CG. In addition, the number of 6-10 years old boys with various postural disorders decreased by 7.4 % (from 26.8 % to 19.4 %).

A standardized anesthetic/analgetic regimen compared to standard anesthetic/analgetic regimen for patients with high-risk factors undergoing open lumbar spine surgery: a prospective comparative single-center study.

The objective of the study is to improve the results of patients undergoing lumbar spine surgery who are at high risk for anesthesia and/or surgical complications. Two independent groups were compared: the study group (SG, n = 40) (standardized neuroanesthetic protocol with multimodal analgesia) and the control group (CG, n = 40) (intravenous anesthesia based on propofol and fentanyl). The data were collected using prospective observation of early and long-term results of lumbar fusion. After 24 months, the level of functional state and quality of life were studied. Patients in the SG did not have statistically significant changes in intraoperative hemodynamics; the best indicators of cognitive functions were noted. The effectiveness of the SG compared with the CG was confirmed by a statistically significantly lower amount of perioperative opioid drugs required (p = 0.01) and a minimal level of incisional pain (p < 0.05). An intergroup comparison of the adverse effects of anesthesia revealed a significantly lower number in the SG (n = 4) compared to the CG (n = 16) (p = 0.004). The number of postoperative surgical complications was comparable (p = 0.72). Intergroup comparison showed improved ODI, SF-36, and the Macnab scale at 24 months after surgery in the SG compared to the CG (p < 0.05). Long-term clinical results correlated with the level of incisional pain in the first three postoperative days. Our standardized neuroanesthetic protocol ensured effective treatment of postoperative incisional pain, significantly decreased the perioperative use of opioids, reduced adverse anesthesia events, and improved long-term clinical results in patients with high risk factors for anesthetic complications who undergoing open lumbar spine surgery.

OBSTETRIC AND PERINATAL ASPECTS OF METABOLIC DISORDERS IN PREGNANT WOMEN.

OBJECTIVE: The aim: To determine the feasibility of using Tivortin in metabolic disorders during pregnancy and its effect on the course of pregnancy, childbirth, fetal and neonatal status. PATIENTS AND METHODS: Materials and methods: We examined 210 pregnant women with metabolic disorders using clinical and laboratory data, uterine artery Doppler, determi¬nation of lipid peroxidation and antioxidant system, leptin and placental growth factor content. The fetal condition was assessed by ultrasound examination with Doppler, determination of biophysical profile, and cardiotocography. RESULTS: Results: Metabolic disorders in pregnant women increase the risk of obstetric and perinatal complications by activating lipid peroxidation and inhibiting the antioxidant system, reducing the content of placental growth factor and increasing the level of leptin in the blood plasma. After treatment, there was a significant decrease in leptin levels and an increase in placental growth factor levels, normalization of lipid peroxidation and antioxidant system, uterine artery pulsatility index and umbilical cord peak systolic velocity index, systolic-diastolic ratio, fetal biophysical profile and cardiotocography. The incidence of complications in childbirth decreased by 3 times, surgical interventions - by 2 times, postpartum infectious complications - by 1.7 times, and the birth of infants in a state of asphyxia - by 1.8 times. CONCLUSION: Conclusions: Metabolic disorders in pregnant women are a significant factor in the development of obstetric and perinatal complications due to the intensity of lipid peroxidation and depression of the antioxidant system, and a decrease in the content of placental growth factor. The use of Tivortin in the treatment of pregnant women with metabolic disorders has proven its safety and efficacy.

Clinical and radiological outcomes of one-level cervical corpectomy with an expandable cage for three-column uncomplicated subaxial type «B¼ injures: a multicenter retrospective study.

PURPOSE: To evaluate the clinical and radiological results of the operative management of three-column uncomplicated type «B¼ subaxial injures treated with a one-level cervical corpectomy with an expandable cage. METHODS: This study included 72 patients with a three-column uncomplicated type «B¼ subaxial injures who met the inclusion criteria, underwent a one-level cervical corpectomy with an expandable cage at one of three neurosurgical departments between 2005 and 2020, and were followed up for clinical and radiological outcomes at a minimum 3-yr follow-up. RESULTS: There was a decrease in the VAS pain score from an average of 80 mm to 7 mm (p = 0.03); a decrease in the average NDI score from 62 to 14% (p = 0.01); excellent and good outcomes according to Macnab's scale were 93% (n = 67/72). There was an average change in the cervical lordosis (Cobb method) from -9.10 to -15.40 (p = 0.007), without significant loss of lordosis (p = 0.27). There was no significant degeneration of the adjacent levels by 3 years post-op. The fusion rate, using the Cervical Spine Research Society criteria, was poor: it was 62.5% (n = 45/72), and using the CT criteria, it was 65.3% (n = 47/72). 15.4% patients (n = 11/72) suffered complications. Statistical difference between the fusion and pseudoarthrosis (according to X-ray criteria) subgroups showed that there were no statistically significant differences in the smoking status, diabetes, chronic steroid use, cervical injury level, subtypes of AO type B subaxial injuries and types of expandable cage systems. CONCLUSIONS: One-level cervical corpectomy with an expandable cage, despite a poor fusion rate, can be considered a feasible and relatively safe method for treating three-column uncomplicated subaxial type «B¼ injures, with the benefit of immediate stability, anatomical reduction, and direct decompression of the spinal cord. While no one in our series had any catastrophic complications, we did note a high complication rate.

Minimally invasive decompression alone versus fusion surgery for acute lumbar disk herniation combined incomplete cauda equina syndrome.

STUDY DESIGN: Retrospective single center study. BACKGROUND: Cauda equine syndrome (CES), which caused by acute lumbar disc herniation (LDH), often requires urgent surgical treatment. Currently, there is no standard defining the type of surgery, and approaches to the treatment of patients are based on the experience of the surgeon. PURPOSE: to compare the clinical efficacy of minimally invasive decompression alone (Decompression alone group) and transforaminal lumbar interbody fusion (Fusion group) in the treatment of the incomplete CES, caused by acute LDH. PATIENTS AND METHODS: 89 patients with acute incomplete CES associated with LDH either underwent decompression alone and fusion surgery from January 2005 to January 2020 in single-center, and data were collected and retrospectively analyzed. The patients were divided into 2 groups according to the operation technics: the Decompression alone group (n = 46) and the Fusion group (n = 43). The perioperative clinical data (neurological deficit, control of the urinary bladder sphincter, ODI scale, SF-36) was used to assess the efficacy of the respective surgical methods before operation and with a minimum follow-up 24 months. RESULTS: Verified statistical significance more bleeding, longer surgery time and hospital stay, in the Fusion group than in the Decompression alone group. The postoperative clinical data dramatic improved after Decompression alone and Fusion surgery. At early postoperative period registered better clinical outcomes according to ODI, SF-36 after Decompression alone surgery, but at minimum follow-up 24 months verified better in the Fusion group. The number of revision interventions in the Decompression alone group was 28.3% (n = 13), in Fusion group - 9.3% (n = 4) (p = 0.02). CONCLUSIONS: The prevalence of acute incomplete CES due to LDH in our series was registered in 1.02% of patients (124 of 12087). In the Fusion group, in the long-term period, there were better clinical outcomes and fewer revision surgical interventions compared with Decompression alone.

Structure and chemopreventive activity of fucoidans from the brown alga Alaria angusta.

Six fucoidan fractions were isolated from the brown alga Alaria angusta. Structures of enzymatic hydrolysis products of the fraction 1AaF2 (Fuc:Gal ~ 1:1; 33 % of sulfates) by fucanase from Wenyingzhuangia fucanilytica were studied by chemical and instrumental (NMR spectroscopy and mass-spectrometry) methods. It was shown that 1AaF2 consisted of two structurally different fucoidans: a sulfated 1,3;1,4-α-L-fucan and an enzyme-resistant sulfated and acetylated complex fucogalactan (Fuc:Gal ~ 1:2; 19 % of sulfates) 1AaF2_HMP containing extended 1,3-linked fucose and 1,3/1,4-linked galactose fragments (up to 5 residues). The fractions 1AaF2 and 1AaF2_HMP were a non-cytotoxic, possessed dose-dependent chemopreventive effect on EGF-induced neoplastic cell transformation of mouse normal epidermal JB6 Cl41 cells and inhibited the colony formation of human melanoma SK-MEL-28 cells.

VULVOVAGINAL CANDIDIASIS AFTER GYNECOLOGICAL SURGERIES AND ADVERSE PREGNANCY OUTCOME IN UKRAINE: A MULTICENTRE STUDY.

OBJECTIVE: The aim: To investigate the epidemiology and microbiology of vulvovaginal candidiasis (VVC) after gynecological surgeries, and adverse pregnancy outcomes in Ukraine. PATIENTS AND METHODS: Materials and methods: Multicenter prospective cohort study was conducted from January 2020 to December 2022 and recruited pregnant and non-pregnant women aged 15-65 years who had sought medical help for vaginal dysbiosis the seven medical clinic from five regions of Ukraine. RESULTS: Results: Between 2020 and 2022, 2,341 women were followed in gynecological practices, and 1,056 (41.5%) women were diagnosed with VVC during the same period. Of the total VVC cases, 31.9% were in non-pregnant and 68.1% in pregnant women. The use of antibiotics (OR=3.48), use hormonal contracep¬tives (OR=2.75) and pregnancy (OR=1.13) were associated with an increase in the risk of VVC diagnosis. Diabetes mellitus (OR=0.44) were additional risk factors. The most common pathogen of VVC was C. albicans, Nakaseomyces glabratus (C. glabrata), followed by Pichia kudriavzevii (C. krusei), C. parapsilosis, C. tropicalis, C. kefyr, C. guillieromondii, C. lusitaniae, and C. rugosa. We found no significant difference in adverse pregnancy outcomes between Candida-positive and Candida-negative women. CONCLUSION: Conclusions: Vulvovaginal candidiasis after gynecological surgeries in Ukraine is a common medical problem in women that is associated with significant morbidity, and hence frequent medical visits. High prevalence rate of vulvovaginal candidiasis in the present study warrants, the importance of conducting continuous epidemiological surveys to measure changes in species distribution from C. albicans to non-albicans Candida species in Ukraine.

STUDY OF THE STRESS-STRAIN STATE OF THE MAXILLA DURING ORTHODONTIC TREATMENT OF DENTOGNATHIC DEFORMATIONS IN CHILDREN WITH CONGENITAL CLEFT LIP AND PALATE.

OBJECTIVE: The aim: To create a three-dimensional simulation mechanical-mathematical model of the biomechanical system "Orthodontic appliance-maxilla", to study peculiarities of the stress-strained state of the maxilla. PATIENTS AND METHODS: Materials and methods: A simulation model of the biomechanical system "Orthodontic appliance-maxilla" was created using computed tomography (CBCT) data. Mathematical modeling was used to determine the stress-strain state of the simulation model. RESULTS: Results: The patterns of changes in the stress state were determined and the values of deformation displacements in the structural elements of the biome-chanical system "Orthodontic appliance-maxilla" were determined under a force stress of the orthodontic device with an amplitude of 50 N. CONCLUSION: Conclusions: Simulation computer modeling of the stress-strain state of the "Orthodontic appliance-maxilla" system showed that activation of the kinematic mechanism of the appliance with a force of 50 N causes the emergence of a complex stress-strain state of bones. When the orthodontic appliance is activated, there is an asymmetry in the distribution of stresses by Mises between the right and left sides both for the appliance itself and for the maxillary bone tissue.

Molecular and Genetic Mechanisms of Spinal Stenosis Formation: Systematic Review.

Spinal stenosis (SS) is a multifactorial polyetiological condition characterized by the narrowing of the spinal canal. This condition is a common source of pain among people over 50 years old. We perform a systematic review of molecular and genetic mechanisms that cause SS. The five main mechanisms of SS were found to be ossification of the posterior longitudinal ligament (OPLL), hypertrophy and ossification of the ligamentum flavum (HLF/OLF), facet joint (FJ) osteoarthritis, herniation of the intervertebral disc (IVD), and achondroplasia. FJ osteoarthritis, OPLL, and HLF/OLFLF/OLF have all been associated with an over-abundance of transforming growth factor beta and genes related to this phenomenon. OPLL has also been associated with increased bone morphogenetic protein 2. FJ osteoarthritis is additionally associated with Wnt/ß-catenin signaling and genes. IVD herniation is associated with collagen type I alpha 1 and 2 gene mutations and subsequent protein dysregulation. Finally, achondroplasia is associated with fibroblast growth factor receptor 3 gene mutations and fibroblast growth factor signaling. Although most publications lack data on a direct relationship between the mutation and SS formation, it is clear that genetics has a direct impact on the formation of any pathology, including SS. Further studies are necessary to understand the genetic and molecular changes associated with SS.

An Algorithmic Posterior Approach to the Treatment of Multilevel Degenerative Cervical Spine Disease: A Multicenter Prospective Study.

BACKGROUND: The choice of surgical method for the treatment of multilevel degenerative cervical spine disease is based on the assessment of neurological symptoms and anatomical source of compression. However, such decision-making process remains complex and poorly defined. PURPOSE: To analyze the effectiveness of an algorithmic posterior approach to the surgical treatment of patients with multilevel degenerative disease of the cervical spine based on the preoperative clinical and imaging parameters. STUDY DESIGN: Prospective nonrandomized multicenter cohort study. METHODS: The study included 338 patients with multilevel degenerative disease of the cervical spine. Two groups of patients were evaluated at 3 neurosurgical centers between 2015 and 2019. The prospective group (Group I, n = 214) consisted of patients who were treated using an algorithm to decide whether they should be treated with an instrumented arthrodesis or a nonfusion procedure. The control group (Group II, n = 124) consisted of patients who underwent posterior decompression with or without stabilization between 2007 and 2014. A total of 192 patients in Group I and 112 in Group II had more than 2 years of follow-up. Visual analog scale (VAS) neck pain, Neck Disability Index (NDI), MacNab and Nurick Scales were collected. Perioperative complications were identified. RESULTS: At 2-year follow-up, Group I had significantly better clinical outcomes based on VAS neck pain score (P = 0.02), NDI score (P = 0.01), satisfaction with surgery on the MacNab Scale (P < 0.001), and outcome of surgery based on the Nurick Scale (P < 0.001). Complication rate was lower in Group I, 5.7% compared with 34.8% in Group II, P = 0.004. CONCLUSIONS: The algorithmic posterior approach to the surgical treatment of patients with multilevel degenerative disease of the cervical spine resulted in significant improvement of functional outcomes and a decrease in complications at a minimum 2 years of follow-up.