In Vitro Prostate Cancer Treatment via CRISPR-Cas9 Gene Editing Facilitated by Polyethyleneimine-Derived Graphene Quantum Dots

CRISPR-Cas9 is a programmable gene editing tool with a promising potential for cancer gene therapy. This therapeutic function is enabled in the present work via the non-covalent delivery of CRISPR ribonucleic protein (RNP) by cationic glucosamine/PEI-derived graphene quantum dots (PEI-GQD) that aid in overcoming physiological barriers and tracking genes of interest. PEI-GQD/RNP complex targeting the TP53 mutation overexpressed in ~50% of cancers successfully produces its double-stranded breaks in solution and in PC3 prostate cancer cells. Restoring this cancer "suicide" gene can promote cellular repair pathways and lead to cancer cell apoptosis. Its repair to the healthy form performed by simultaneous PEI-GQD delivery of CRISPR RNP and a gene repair template leads to a successful therapeutic outcome: 40% apoptotic cancer cell death, while having no effect on non-cancerous HeK293 cells. The translocation of PEI-GQD/RNP complex into PC3 cell cytoplasm is tracked via GQD intrinsic fluorescence, while EGFP-tagged RNP is detected in the cell nucleus, showing the successful detachment of the gene editing tool upon internalization. Using GQDs as non-viral delivery and imaging agents for CRISPR-Cas9 RNP sets the stage for image-guided cancer-specific gene therapy.

Doped Graphene Quantum Dots as Biocompatible Radical Scavenging Agents

Oxidative stress is proven to be a leading factor in a multitude of adverse conditions, from Alzheimer's disease to cancer. Thus, developing effective radical scavenging agents to eliminate reactive oxygen species (ROS) driving many oxidative processes has become critical. In addition to conventional antioxidants, nanoscale structures and metal-organic complexes have recently shown promising potential for radical scavenging. To design an optimal nanoscale ROS scavenging agent, we have synthesized ten types of biocompatible graphene quantum dots (GQDs) augmented with various metal dopants. The radical scavenging abilities of these novel metal-doped GQD structures were, for the first time, assessed via the DPPH, KMnO4, and RHB (Rhodamine B protectant) assays. While all metal-doped GQDs consistently demonstrate antioxidant properties higher than the undoped cores, aluminum-doped GQDs exhibit 60-95% radical scavenging ability of ascorbic acid positive control. Tm-doped GQDs match the radical scavenging properties of ascorbic acid in the KMnO4 assay. All doped GQD structures possess fluorescence imaging capabilities that enable their tracking in vitro, ensuring their successful cellular internalization. Given such multifunctionality, biocompatible doped GQD antioxidants can become prospective candidates for multimodal therapeutics, including the reduction of ROS with concomitant imaging and therapeutic delivery to cancer tumors.

Automated Approach to In Vitro Image-Guided Photothermal Therapy with Top-Down and Bottom-Up-Synthesized Graphene Quantum Dots

Graphene-based materials have been the subject of interest for photothermal therapy due to their high light-to-heat conversion efficiency. Based on recent studies, graphene quantum dots (GQDs) are expected to possess advantageous photothermal properties and facilitate fluorescence image-tracking in the visible and near-infrared (NIR), while surpassing other graphene-based materials in their biocompatibility. Several GQD structures including reduced graphene quantum dots (RGQDs) derived from reduced graphene oxide via top-down oxidation and hyaluronic acid graphene quantum dots (HGQDs) hydrothermally bottom-up synthesized from molecular hyaluronic acid were employed to test these capabilities in the present work. These GQDs possess substantial NIR absorption and fluorescence throughout the visible and NIR beneficial for in vivo imaging while being biocompatible at up to 1.7 mg/mL concentrations. In aqueous suspensions, RGQDs and HGQDs irradiated with a low power (0.9 W/cm2) 808 nm NIR laser facilitate a temperature increase up to 47.0 °C, which is sufficient for cancer tumor ablation. In vitro photothermal experiments sampling multiple conditions directly in the 96-well plate were performed using an automated simultaneous irradiation/measurement system developed on the basis of a 3D printer. In this study, HGQDs and RGQDs facilitated the heating of HeLa cancer cells up to 54.5 °C, leading to the drastic inhibition of cell viability from over 80% down to 22.9%. GQD's fluorescence in the visible and NIR traces their successful internalization into HeLa cells maximized at 20 h suggesting both extracellular and intracellular photothermal treatment capabilities. The combination of the photothermal and imaging modalities tested in vitro makes the GQDs developed in this work prospective agents for cancer theragnostics.

[Personalized patient-oriented approach to the treatment of musculoskeletal pain syndrome using over-the-counter medications. Resolution of the Expert Council (May 28, 2023)]

Diseases of the musculoskeletal system in Russia affect 19.2 million people. Untimely diagnosis and inadequate therapy of pain syndrome negatively affect the daily functioning and quality of life of patients, and create significant socioeconomic problems. The most common variants of musculoskeletal pain (MSP) are osteoarthritis (OA) and low back pain (LBP). OA is seen in 57.6% of individuals over 65 years of age. It should be noted that chronic pain syndrome, rather than anatomical and degenerative changes detected by imaging studies, determines to a greater extent the quality of life of patients with OA and prognosis during the course of the disease. The global burden of disability associated with LBPD increased in all age groups between 1990 and 2019 and was highest in the 50-54 age group.

On the accuracy of Covid-19 forecasting methods in Russia for two years

The effectiveness of predicting the dynamics of the coronavirus pandemic for Russia as a whole and for Moscow is studied for a two-year period beginning March 2020. The comparison includes well-proven population models and statistic methods along with a new data-driven model based on the LSTM neural network. The latter model is trained on a set of Russian regions simultaneously, and predicts the total number of cases on the 14-day forecast horizon. Prediction accuracy is estimated by the mean absolute percent error (MAPE). The results show that all the considered models, both simple and more complex, have similar efficiency. The lowest error achieved is 18% MAPE for Moscow and 8% MAPE for Russia.

Dual-Mode Fluorescence/Ultrasound Imaging with Biocompatible Metal-Doped Graphene Quantum Dots

Sonography offers many advantages over standard methods of diagnostic imaging due to its non-invasiveness, substantial tissue penetration depth, and low cost. The benefits of ultrasound imaging call for the development of ultrasound-trackable drug delivery vehicles that can address a variety of therapeutic targets. One disadvantage of the technique is the lack of high-precision imaging, which can be circumvented by complementing ultrasound contrast agents with visible and, especially, near-infrared (NIR) fluorophores. In this work, we, for the first time, develop a variety of lightly metal-doped (iron oxide, silver, thulium, neodymium, cerium oxide, cerium chloride, and molybdenum disulfide) nitrogen-containing graphene quantum dots (NGQDs) that demonstrate high-contrast properties in the ultrasound brightness mode and exhibit visible and/or near-infrared fluorescence imaging capabilities. NGQDs synthesized from glucosamine precursors with only a few percent metal doping do not introduce additional toxicity in vitro, yielding over 80% cell viability up to 2 mg/mL doses. Their small (<50 nm) sizes warrant effective cell internalization, while oxygen-containing surface functional groups decorating their surfaces render NGQDs water soluble and allow for the attachment of therapeutics and targeting agents. Utilizing visible and/or NIR fluorescence, we demonstrate that metal-doped NGQDs experience maximum accumulation within the HEK-293 cells 6-12 h after treatment. The successful 10-fold ultrasound signal enhancement is observed at 0.5-1.6 mg/mL for most metal-doped NGQDs in the vascular phantom, agarose gel, and animal tissue. A combination of non-invasive ultrasound imaging with capabilities of high-precision fluorescence tracking makes these metal-doped NGQDs a viable agent for a variety of theragnostic applications.

Detection of Pancreatic Cancer miRNA with Biocompatible Nitrogen-Doped Graphene Quantum Dots

Early-stage pancreatic cancer remains challenging to detect, leading to a poor five-year patient survival rate. This obstacle necessitates the development of early detection approaches based on novel technologies and materials. In this work, the presence of a specific pancreatic cancer-derived miRNA (pre-miR-132) is detected using the fluorescence properties of biocompatible nitrogen-doped graphene quantum dots (NGQDs) synthesized using a bottom-up approach from a single glucosamine precursor. The sensor platform is comprised of slightly positively charged (1.14 ± 0.36 mV) NGQDs bound via π-π stacking and/or electrostatic interactions to the negatively charged (-22.4 ± 6.00 mV) bait ssDNA; together, they form a complex with a 20 nm average size. The NGQDs' fluorescence distinguishes specific single-stranded DNA sequences due to bait-target complementarity, discriminating them from random control sequences with sensitivity in the micromolar range. Furthermore, this targetability can also detect the stem and loop portions of pre-miR-132, adding to the practicality of the biosensor. This non-invasive approach allows cancer-specific miRNA detection to facilitate early diagnosis of various forms of cancer.

The prevalence of osteoarthritis and its association with geriatric syndromes in people over 65: data from the Russian epidemiological study EVKALIPT

Background. Osteoarthritis (OA) in elderly and senile patients is not only common, but also one of the main diseases affecting the duration of active life, its quality, the appearance of addictions and loss of autonomy. Data on the relationship between OA and geriatric syndromes (GS) in our country are extremely scarce. Aim. To estimate the prevalence of OA and to analyze its associations with HS in persons aged 65 years. Materials and methods. The study included 4308 people (30% of men) aged 65 to 107 years, living in 11 regions of Russia. The patients were divided into 2 groups: with OA (n=2464) and without OA (n=1821). All patients underwent a comprehensive geriatric assessment. Results. The prevalence of OA was 57.6%. With age, the frequency of OA increased significantly. According to the results of a comprehensive geriatric assessment, patients with OA had lower walking speed, the sum of points on the Bartel, Lawton scales and a short battery of physical functioning tests and higher the sum of points on the geriatric scale of depression and the age is not a hindrance scale. Patients with OA rated the quality of life and health status lower and higher the intensity of pain syndrome. Patients with OA were more likely to use any assistive device, with the exception of a wheelchair. In patients with OA, the most common HS were chronic pain syndrome (92%), senile asthenia syndrome (64%), basic (66%) and instrumental (56%) dependence in everyday life, cognitive impairment (62%), probable depression (51%) and urinary incontinence (50%). Univariate regression analysis showed that OA is associated with a 1.23.0-fold increase in the risk of a number of GS and a 28% decrease in the risk of malnutrition. Conclusion. OA is widespread in the elderly population. The presence of OA is associated with a number of GS associated with loss of autonomy.

The prevalence of anemia and its associations with other geriatric syndromes in subjects over 65 years old: data of Russian epidemiological study EVKALIPT

Background. A low hemoglobin level in older adults impairs cognitive ability and functional status and associates with risk of falls and fractures, sarcopenia, malnutrition, depression, frailty, and decreased autonomy. Epidemiological data on the anemia prevalence in the geriatric population in our country is not available. Aim. To assess the prevalence of anemia and analyze its associations with geriatric syndromes (GS) in subjects aged 65 years. Materials and methods. 4308 subjects (30% of men) aged 65107 years, living in 11 regions of the Russian Federation, were examined and divided into age groups (6574 years, 7584 years and 85 years). All the participants underwent a comprehensive geriatric assessment and determined hemoglobin level. Results. The anemia prevalence in older adults was 23.9%. It has been shown that with an increase in age per 1 year, the risk of anemia detection increases by 4%. The incidence of anemia was higher in males than females (28.1% versus 22.1%; p0.001). In most cases, anemia was mild. The results of a comprehensive geriatric assessment show that patients with anemia had lower hand grip force, Barthel Index, the sum of points on Lawton instrumental activities of daily living scale, Mini Nutritional Assessment scale, the Mini-Cog test and higher the sum of points on the Geriatric Depression Scale (GDS-15) and the Age Is No Barrier scale. Patients with anemia were more likely to use hearing aids, absorbent underwear, and assistive devices during movement. Patients with anemia had a higher incidence of all GS, except for orthostatic hypotension and chronic pain syndrome. The presence of GS is associated with an increased risk of anemia by 1.33.4 times. Conclusion. EVKALIPT study obtained domestic data on the prevalence of anemia in older patients and examined its associations with other GS.

Using mathematical modeling to estimate time-independent cancer chemotherapy efficacy parameters

One of the primary cancer treatment modalities is chemotherapy. Unfortunately, traditional anti-cancer drugs are often not selective and cause damage to healthy cells, leading to serious side effects for patients. For this reason more targeted therapeutics and drug delivery methods are being developed. The effectiveness of new treatments is initially determined via in vitro cell viability assays, which determine the IC 50  of the drug. However, these assays are known to result in estimates of IC 50  that depend on the measurement time, possibly resulting in over- or under-estimation of the IC 50 . Here, we test the possibility of using cell growth curves and fitting of mathematical models to determine the IC 50  as well as the maximum efficacy of a drug ( ε max ). We measured cell growth of MCF-7 and HeLa cells in the presence of different concentrations of doxorubicin and fit the data with a logistic growth model that incorporates the effect of the drug. This method leads to measurement time-independent estimates of IC 50  and ε max , but we find that ε max  is not identifiable. Further refinement of this methodology is needed to produce uniquely identifiable parameter estimates.

Baseline Accuracies of Forecasting COVID-19 Cases in Russian Regions on a Year in Retrospect Using Basic Statistical and Machine Learning Methods

The large amount of data accumulated so far on the dynamics of the COVID-19 outbreak has allowed assessing the accuracy of forecasting methods in retrospect. This work compares several basic time series analysis methods, including machine learning methods, for forecasting the number of confirmed cases for some days ahead. Year-long data for all regions of Russia has been used from the Yandex DataLens platform. As a result, accuracy estimates for these basic methods have been obtained for Russian regions and Russia as a whole, in dependence on the forecasting horizon. The best basic models for forecasting for 14 days are exponential smoothing and ARIMA, with an error of 11-19% by the MAPE metric for the latest part of the course of the epidemic. The accuracies obtained can be considered as baselines for more complex prospective models.

Graphene quantum dot formulation for cancer imaging and redox-based drug delivery

This work develops a new multifunctional biocompatible anticancer nanoformulation to provide targeted image-guided cancer-selective therapeutics. It consists of three active covalently bound components: (1) biocompatible nitrogen-doped graphene quantum dots (GQDs) as a multifunctional delivery and imaging platform, (2) hyaluronic acid (HA) unit targeted to the CD44 receptors on a variety of cancer cells, and (3) oxidative stress-based cancer-selective ferrocene (Fc) therapeutic. The biocompatible GQD platform synthesized from glucosamine exhibits high-yield intrinsic fluorescence. It is utilized for tracking Fc-GQD-HA formulation in vitro indicating internalization enhancement in HeLa cells targeted by the HA over non-cancer HEK-293 cells not overexpressing CD44 receptor. Fc-GQD-HA, non-toxic at 1 mg/mL to HEK-293 cells, induces cytotoxic response in HeLa enhanced over time, while therapeutic ROS generation by Fc-GQD-HA is ~3 times greater than that of Fc alone. This outlines the targeted delivery, imaging, and cancer-specific treatment capabilities of the new Fc-GQD-HA formulation enabling desired cancer-focused nanotherapeutic approach.

Manganese-nitrogen and gadolinium-nitrogen Co-doped graphene quantum dots as bimodal magnetic resonance and fluorescence imaging nanoprobes

Graphene quantum dots (GQDs) are unique derivatives of graphene that show promise in multiple biomedical applications as biosensors, bioimaging agents, and drug/gene delivery vehicles. Their ease in functionalization, biocompatibility, and intrinsic fluorescence enable those modalities. However, GQDs lack deep tissue magnetic resonance imaging (MRI) capabilities desirable for diagnostics. Considering that the drawbacks of MRI contrast agent toxicity are still poorly addressed, we develop novel Mn²⁺ or Gd³⁺ doped nitrogen-containing graphene quantum dots (NGQDs) to equip the GQDs with MRI capabilities and at the same time render contrast agents biocompatible. Water-soluble biocompatible Mn-NGQDs and Gd-NGQDs synthesized via single-step microwave-assisted scalable hydrothermal reaction enable dual MRI and fluorescence modalities. These quasi-spherical 3.9-6.6 nm average-sized structures possess highly crystalline graphitic lattice structure with 0.24 and 0.53 atomic % for Mn²⁺ and Gd³⁺ doping. This structure ensures high in vitro biocompatibility of up to 1.3 mg ml^-1 and 1.5 mg ml^-1 for Mn-NGQDs and Gd-NGQDs, respectively, and effective internalization in HEK-293 cells traced by intrinsic NGQD fluorescence. As MRI contrast agents with considerably low Gd and Mn content, Mn-NGQDs exhibit substantial transverse/longitudinal relaxivity (r ₂/r ₁) ratios of 11.190, showing potential as dual-mode longitudinal or transverse relaxation time (T ₁ or T ₂) contrast agents, while Gd-NGQDs possess r ₂/r ₁ of 1.148 with high r ₁ of 9.546 mM^-1 s^-1 compared to commercial contrast agents, suggesting their potential as T1 contrast agents. Compared to other nanoplatforms, these novel Mn²⁺ and Gd³⁺ doped NGQDs not only provide scalable biocompatible alternatives as T1/T2 and T1 contrast agents but also enable in vitro intrinsic fluorescence imaging.

Graphene Quantum Dots as Intracellular Imaging-Based Temperature Sensors

Non-invasive temperature sensing is necessary to analyze biological processes occurring in the human body, including cellular enzyme activity, protein expression, and ion regulation. To probe temperature-sensitive processes at the nanoscale, novel luminescence nanothermometers are developed based on graphene quantum dots (GQDs) synthesized via top-down (RGQDs) and bottom-up (N-GQDs) approaches from reduced graphene oxide and glucosamine precursors, respectively. Because of their small 3-6 nm size, non-invasive optical sensitivity to temperature change, and high biocompatibility, GQDs enable biologically safe sub-cellular resolution sensing. Both GQD types exhibit temperature-sensitive yet photostable fluorescence in the visible and near-infrared for RGQDs, utilized as a sensing mechanism in this work. Distinctive linear and reversible fluorescence quenching by up to 19.3% is observed for the visible and near-infrared GQD emission in aqueous suspension from 25 °C to 49 °C. A more pronounced trend is observed with GQD nanothermometers internalized into the cytoplasm of HeLa cells as they are tested in vitro from 25 °C to 45 °C with over 40% quenching response. Our findings suggest that the temperature-dependent fluorescence quenching of bottom-up and top-down-synthesized GQDs studied in this work can serve as non-invasive reversible/photostable deterministic mechanisms for temperature sensing in microscopic sub-cellular biological environments.

Experimental and theoretical inquiry into optical properties of graphene derivatives

Graphene oxide (GO), a functional derivative of graphene, is a promising nanomaterial for a variety of optoelectronic applications as it exhibits fluorescence and maintains many of graphene's beneficial physical properties. although other graphene derivatives are chemically plausible and may serve to the benefit of the aforementioned applications, GO remains the one heavily used. the nature of optical behavior of other graphene derivatives has yet to be fully understood and studied. in this work we develop a variety of graphene derivatives and characterize their optical properties concomitantly suggesting a unified model for optical emission in graphene derivatives. in this process we examine the influence of different functional groups on the surface of graphene on its optoelectronic properties. mildly oxidized graphene (oxo-g₁), nitrated graphene, arylated graphene, brominated graphene, and fluorinated graphene are obtained and characterized via TEM and EDX, FTIR and fluorescence spectroscopies with the latter indicating a potential band gap-derived fluorescence from each of the materials. this suggests that optical properties of graphene derivatives have minimal functional group dependence and are manifested by the localized environments within the flakes. this is confirmed by the hyperchem theoretical modeling of all aforementioned graphene derivatives indicating a similar electronic configuration for all, assessed by the pm3 semi-empirical approach. this work can further serve to describe and predict optical properties of similar graphene-based structures and promote graphene derivatives other than GO for utilization in research and industry.

Rare-Earth-Doped Cerium Oxide Nanocubes for Biomedical Near-Infrared and Magnetic Resonance Imaging

Near-infrared (NIR) fluorescence provides a new avenue for biomedical fluorescence imaging that allows for the tracking of fluorophore through several centimeters of biological tissue. However, such fluorophores are rare and, due to accumulation-derived toxicity, are often restricted from clinical applications. Deep tissue imaging not only provided by near-infrared fluorophores but also conventionally carried out by magnetic resonance imaging (MRI) or computed tomography (CT) is also hampered by the toxicity of the contrast agents. This work offers a biocompatible imaging solution: cerium oxide (CeO₂) nanocubes doped with ytterbium or neodymium, and co-doped with gadolinium, showing simultaneous potential for near-infrared (NIR) fluorescence and magnetic resonance imaging (MRI) applications. A synthetic process described in this work allows for the stable incorporation of ytterbium or neodymium, both possessing emissive transitions in the NIR. As a biocompatible nanomaterial, the CeO₂ nanocubes act as an ideal host material for doping, minimizing lanthanide fluorescence self-quenching as well as any potential toxicity associated with the dopants. The uptake of nanocubes by HeLa cells maximized at 12 h was monitored by hyperspectral imaging of the ytterbium or neodymium NIR emission, indicating the capacity of the lanthanide-doped nanocubes for in vitro and a potential for in vivo fluorescence imaging. The co-doped nanocubes demonstrate no significant loss of NIR emission intensity upon co-doping with 2 atomic % gadolinium and exhibit magnetic susceptibilities in the range of known negative contrast agents. However, a small increase to 6 atomic % gadolinium significantly affects the magnetic susceptibility ratio (r₂/r₁), shifting closer to the positive contrast range and suggesting the potential use of the CeO₂ nanocube matrix doped with selected rare-earth ions as a tunable MRI contrast agent with NIR imaging capabilities.

Electric field quenching of graphene oxide photoluminescence

With the advent of graphene, there has been an interest in utilizing this material and its derivative, graphene oxide (GO) for novel applications in nanodevices such as bio and gas sensors, solid-state supercapacitors and solar cells. Although GO exhibits lower conductivity and structural stability, it possesses an energy band gap that enables fluorescence emission in the visible/near infrared leading to a plethora of optoelectronic applications. In order to allow fine-tuning of its optical properties in the device geometry, new physical techniques are required that, unlike existing chemical approaches, yield substantial alteration of GO structure. Such a desired new technique is one that is electronically controlled and leads to reversible changes in GO optoelectronic properties. In this work, we for the first time investigate the methods to controllably alter the optical response of GO with the electric field and provide theoretical modeling of the electric field-induced changes. Field-dependent GO emission is studied in bulk GO/polyvinylpyrrolidone films with up to 6% reversible decrease under 1.6 V µm^-1 electric fields. On an individual flake level, a more substantial over 50% quenching is achieved for select GO flakes in a polymeric matrix between interdigitated microelectrodes subject to two orders of magnitude higher fields. This effect is modeled on a single exciton level by utilizing Wentzel, Kremer, and Brillouin approximation for electron escape from the exciton potential well. In an aqueous suspension at low fields, GO flakes exhibit electrophoretic migration, indicating a degree of charge separation and a possibility of manipulating GO materials on a single-flake level to assemble electric field-controlled microelectronics. As a result of this work, we suggest the potential of varying the optical and electronic properties of GO via the electric field for the advancement and control over its optoelectronic device applications.

[Falls and pathology of the musculoskeletal system in the older age groups]

BACKGROUND

Fall in the elderly is considered as a geriatric syndrome, which increases the risk of new falls, decreases physical functioning and autonomy and is associated with other geriatric syndromes. One of the most common risk factors for falls is the pathology of the musculoskeletal system, including osteoarthritis, sarcopenia, osteopenia and osteoporosis, as well as chronic pain.

AIM

To characterize diseases of the musculoskeletal system in elderly patients with falls.

MATERIAL AND METHODS

The study included 289 patients (mean age 75,8±7,9 years, 224 women) who underwent falls during the last year. All patients had polymorbid pathology (mean number of diseases 5,13±2,3, the Charlson index 5,63±1,8 points). All patients underwent general clinical studies, a comprehensive geriatric assessment, X-ray examination of the joints, dual-energy X-ray absorptiometry.

RESULTS AND CONCLUSION

The risk of falls assessed with a self-assessment scale as 7,45±3 points had 90,3% of patients, 34,6% of patients had the high hospital risk of falls. All patients had aggravated geriatric status (on average 7 geriatric syndromes). Among the risk factors for falls, one of the most common was the condition associated with the pathology of the musculoskeletal system: chronic pain (84,7%), physical inactivity (56,1%), disorders of balance (60,2%) and gait (35,9%), the use of mobility aids (30,4%), orthopedic pathology (9,7%) and vitamin D deficiency (86,1%). Osteoarthritis prevailed (75,8%) among nosological forms. One hundred and forty-two (64,8%) patients had pain in the joints, the duration of pain was 6,2±5,6 days, the pain intensity was 47,2±20,7 mm on a visual analogue scale and 106,3±112,3 points by WOMAC. The neuropathic component was diagnosed on DN4 scale in 34 (23,9%) patients. Dynapenia was detected in 109 (37,7%) patients, and sarcopenia in 28 (25,6%) of them. The risk of osteoporotic fractures was 17,4±7,9%. The significantly higher incidence of dynapenia, insufficiency and deficiency of vitamin D and a higher risk of osteoporotic fractures was observed in 289 patients with falls compared to 213 people without falls.

[The efficacy and safety of intra-articular application of a combination of sodium hyaluronate and chondroitin sulfate for osteoarthritis of the knee: a multicenter prospective study]

in 3 mL on patients with knee osteoarthritis (OA) in a multicenter prospective study.

MATERIALS AND METHODS

79 outpatients (predominantly females 81.0%) from 5 RF constituent territories with primary tibiofemoral KellgrenLawrence score grade II or III knee OA, 40 mm pain intensity during walking on visual analogue scale (VAS), requiring NSAIDs intake (for at least 30 days during 3 months prior to enrollment) were included into the study after signing the informed consent form. Mean age was 60.38.7 years, mean BMI 29.24.7 kg/m2, disease duration 6 (310) years. Grade II OA was documented in 68.4% of patients, Grade III in 31.6%. The study lasted for 6 months. Efficacy and safety evaluations were made based on VAS pain assessment, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) [WOMAC pain (0500), WOMAC function (01700), WOMAC stiffness (0200)], VAS patients health status, EQ-5D-based assessment of patients quality of life, global physicians and patients efficacy assessment, and daily NSAIDs requirements.

RESULTS

Obtained results demonstrate statistically significant VAS pain reduction during walking already in 1 week after intra-articular injection of the combination [respectively, 62 (5572) and 41 (3251) mm, р0.0001]. Moreover, pain continued to subside during all 3 months of follow up [in 1 month 28 (2042), in 3 month 22 (1437) mm]. A significant pan reduction achieved at Mo 3 persisted until Mo 6 20 (1442) mm, without documented pain increase. Similar trends were observed with total WOMAC score [1125 (8991540) at baseline, and 552 (309837) mm by the end of the study, p0.0001], and all WOMAC sub-scores [268 (189312) baseline WOMAC pain, 91 (48171) mm by the end of the study p0.0001; stiffness 101 (59130) and 40 (2061) mm, p0.0001; function 802 (6471095) and 402 (191638) mm, p0.0001, respectively]. Median time to the onset of therapeutic effect was 7 (518) days. Statistically significant improvement of patients quality of life by EQ-5D and general health status was observed during all follow up period [respectively, 0.52 (-0.020.59) and 0.69 (0.590.80), р0.0001; 48 (3060) and 72 (6080) mm, р0.0001]. One injection of the drug resulted in dose reduction or discontinuation of NSAIDs therapy: at baseline 76 patients (96.2%) were taking NSAIDs, in one week 31 (39.2%) patients discontinued NSAIDs, in 1 month 72.2%, in 3 months 73.4%, and by the end of the study at Mo 6 54.4% were not taking NSAIDs. These data were consistent with physicians and patients global assessment of the efficacy of treatment, who stated significant improvement and improvement in the majority of cases, with only few no effect or worsening cases documented in analyzed population. Adverse events, such as worsening of pain and/or swelling of the joint, were documented in 8 patients (10.1%); they resolved spontaneously or following NSAIDs intake.

CONCLUSION

These results suggest that intra-articular injections of hyaluronic acid plus chondroitin sulfate in patients with knee OA are efficient and safe. A single injection of the drug resulted in statistically significant reduction of pain and stiffness, reduction in NSAIDs intake, as well as improvement in patients quality of life and function.

[The place of chondroitin sulfate and glucosamine sulfate in osteoarthritis pain therapy: a practical view from evidence-based medicine]

Osteoarthritis is one of the leading causes of a chronic pain in elderly people. Old and very old age in itself is a risk factor of a comorbidity, which often limits the therapy specified in clinical recommendations. First of all, it concerns NSAID. In such situations, priority is given to chondroitin sulfate (CS) and glucosamine sulfate (GS) having the anti-inflammatory properties comparable with effects of NSAID. CS and GS also promote the delay in progression of degenerative processes and restoration of the structure of cartilaginous tissue. The drugs of CS and GS groups are Chondroguard and Sustaguard Artro having the considerable evidence-based efficacy and safety and also a polymodality of effects in patients with a combination of osteoarthritis and socially important diseases (atherosclerosis, diabetes mellitus type 2, oncological diseases) and also geriatric syndromes (sarcopenia) and aging in general.

[Anemia in the elderly: influence on physical, functional status and prognosis.]

Anemia in older patients can be seen as a geriatric syndrome that impairs quality of life, functional status, reduces autonomy, and affects prognosis. Anemia is associated with other geriatric syndrome such as frailty, sarcopenia, falls and fractures, vitamin D deficiency, dementia and others. Iron deficiency anemia is the most common. Most often in older persons, the causes of its development are chronic blood loss and malnutrition. Laboratory criteria confirming iron deficiency anemia are hemoglobin reduction, microcytosis, low serum iron and ferritin. This is the basis for the administration of iron preparations, among which two- and threevalent ones are isolated. Trivalent iron preparations are most preferred in older patients because they have better tolerance and less frequency of side effects with comparable efficacy with divalent preparations.

[The clinical status and treatment options for osteoarthritis in patients with frailty]

Aging is an independent risk factor for the development of many diseases and geriatric syndromes. Osteoarthritis (OA), as the most common joint disease in the elderly, can be attributed to age - associated conditions. And the most significant geriatric syndrome, which dramatically affects the management and prognosis of an elderly, is frailty. The review provides current information on the prevalence of OA and frailty, their clinical and prognostic significance, and also shows the mutually aggravating role of these two conditions. The difference between non - and medication management of patients with OA and frailty is emphasized.

[Osteoarthritis and geriatric syndromes]

AIM

To study the geriatric status of patients with osteoarthritis (OA) older than 60 years depending on the severity of frailty.

MATERIAL AND METHODS

The study included 201 patients with OA (mean age 75.84±8.09 years). The patients were divided into 3 groups: patients without frailty, patients with prefrailty and patients with frailty. Along with clinical examination, the risk of falls, pain intensity, the Charlson comorbidity index and the number of geriatric syndromes were calculated.

RESULTS AND CONCLUSION

With the increase of frailty, the number of patients experiencing difficulties in movement increases. The physical activity of the patients gradually reduces with the appearance of prefrailty and significantly reduces in OA. At the same time, there is the increase in dependence on outside help, the decrease in IADL and walking speed. The most common geriatric syndromes in patients with OA are sensory deficits, chronic pain syndrome and falls. The neuropathic component of pain is diagnosed in every tenth patient with OA without frailty and in every third patient with OA and frailty. In light of results obtained in the study, the authors suggest detailed recommendations for treatment of patients.

Single-Walled Carbon Nanotube-Assisted Antibiotic Delivery and Imaging in S. epidermidis Strains Addressing Antibiotic Resistance

Although conventional antibiotics have evolved as a staple of modern medicine, increasing antibiotic resistance and the lack of antibiotic efficacy against new bacterial threats is becoming a major medical threat. In this work, we employ single-walled carbon nanotubes (SWCNTs) known to deliver and track therapeutics in mammalian cells via intrinsic near-infrared fluorescence as carriers enhancing antibacterial delivery of doxycycline and methicillin. SWCNTs dispersed in water by antibiotics without the use of toxic bile salt surfactants facilitate efficacy enhancement for both antibiotics against Staphylococcus epidermidis strain showing minimal sensitivity to methicillin. Doxycycline to which the strain did not show resistance in complex with SWCNTs provides only minor increase in efficacy, whereas the SWCNTs/methicillin complex yields up to 40-fold efficacy enhancement over antibiotics alone, suggesting that SWCNT-assisted delivery may circumvent antibiotic resistance in that bacterial strain. At the same time SWCNT/antibiotic formulations appear to be less toxic to mammalian cells than antibiotics alone suggesting that nanomaterial platforms may not restrict potential biomedical applications. The improvement in antibacterial performance with SWCNT delivery is tested via 3 independent assays-colony count, MIC (Minimal Inhibitory Concentration) turbidity and disk diffusion, with the statistical significance of the latter verified by ANOVA and Dunnett's method. The potential mechanism of action is attributed to SWCNT interactions with bacterial cell wall and adherence to the membrane, as substantial association of SWCNT with bacteria is observed-the near-infrared fluorescence microscopy of treated bacteria shows localization of SWCNT fluorescence in bacterial clusters, scanning electron microscopy verifies SWCNT association with bacterial surface, whereas transmission electron microscopy shows individual SWCNT penetration into bacterial cell wall. This work characterizes SWCNTs as novel advantageous antibiotic delivery/imaging agents having the potential to address antibiotic resistance.

Variation of Optical Properties of Nitrogen-doped Graphene Quantum Dots with Short/Mid/Long-wave Ultraviolet for the Development of the UV Photodetector

Nitrogen-doped graphene quantum dots (NGQDs) synthesized from a single glucosamine precursor are utilized to develop a novel UV photodetector. Optical properties of NGQDs can be altered with short- (254 nm), mid- (302 nm), and long-wave (365 nm) ultraviolet (UV) exposure leading to the reduction of absorption from deep to mid UV (200-320 nm) and enhancement above 320 nm. Significant quenching of blue and near-IR fluorescence accompanied by the dramatic increase of green/yellow emission of UV-treated NGQDs can be used as a potential UV-sensing mechanism. These emission changes are attributed to the reduction of functional groups detected by Fourier transformed infrared spectroscopy and free-radical-driven polymerization of the NGQDs increasing their average size from 4.70 to 11.20 nm at 60 min treatment. Due to strong UV absorption and sensitivity to UV irradiation, NGQDs developed in this work are utilized to fabricate UV photodetectors. Tested under long-/mid-/short-wave UV, these devices show high photoresponsivity (up to 0.59 A/W) and excellent photodetectivity (up to 1.03 × 10¹¹ Jones) with highly characteristic wavelength-dependent reproducible response. This study suggests that the optical/structural properties of NGQDs can be controllably altered via different wavelength UV treatment leading us to fabricate NGQD-based novel UV photodetectors providing high responsivity and detectivity.

Multi-Drug/Gene NASH Therapy Delivery and Selective Hyperspectral NIR Imaging Using Chirality-Sorted Single-Walled Carbon Nanotubes

Single-walled carbon nanotubes (SWCNTs) can serve as drug delivery/biological imaging agents, as they exhibit intrinsic fluorescence in the near-infrared, allowing for deeper tissue imaging while providing therapeutic transport. In this work, CoMoCAT (Cobalt Molybdenum Catalyst) SWCNTs, chirality-sorted by aqueous two-phase extraction, are utilized for the first time to deliver a drug/gene combination therapy and image each therapeutic component separately via chirality-specific SWCNT fluorescence. Each of (7,5) and (7,6) sorted SWCNTs were non-covalently loaded with their specific payload: the PI3 kinase inhibitor targeting liver fibrosis or CCR5 siRNA targeting inflammatory pathways with the goal of addressing these processes in nonalcoholic steatohepatitis (NASH), ultimately to prevent its progression to hepatocellular carcinoma. PX-866-(7,5) SWCNTs and siRNA-(7,6) SWCNTs were each imaged via characteristic SWCNT emission at 1024/1120 nm in HepG2 and HeLa cells by hyperspectral fluorescence microscopy. Wavelength-resolved imaging verified the intracellular transport of each SWCNT chirality and drug release. The therapeutic efficacy of each formulation was further demonstrated by the dose-dependent cytotoxicity of SWCNT-bound PX-866 and >90% knockdown of CCR5 expression with SWCNT/siRNA transfection. This study verifies the feasibility of utilizing chirality-sorted SWCNTs for the delivery and component-specific imaging of combination therapies, also suggesting a novel nanotherapeutic approach for addressing the progressions of NASH to hepatocellular carcinoma.

[Chronic pain in patients older than 60 years: a view of the geriatrics]

AIM

To analyze the geriatric status of patients with chronic pain.

MATERIAL AND METHODS

One hundred and sixteen patients of a geriatric unit, aged 75.66±7.98 years (110 women, 94.8%), were studied. All patients underwent general clinical examination and complex geriatric assessment, on the results of which geriatric syndromes were identified. Characteristics of pain syndrome (cause, intensity, localization) are described.

RESULTS

Chronic pain syndrome is identified in 85 (73.3%) patients. Most often pain is localized in large joints (n=44 (51.76%)) and back (n=50 (58.8%)). The intensity of pain was higher in patients with moderate dependence in daily activities compared to those with mild dependence (p<0.05). Pain intensity is associated with the degree of impairment of physical functioning (p<0.05). Patients with chronic pain have more geriatric symptoms (6.8±2.8). More syndromes (9.11±2.37) are identified in patients with marked impairment of physical functioning. The reduction of muscle strength is observed in 45.9% patients with- and 9.7% patients without chronic pain syndrome. The velocity of pace is 0.59 m/s and 0.71 m/s, respectively.

CONCLUSION

The high prevalence of chronic pain in patients of a geriatric unit is shown. The intensity of pain iss higher in patients with moderate dependence in daily activities compared to those with mild dependence. Pain intensity increases with the reduction of patient's physical functioning. Patients with chronic pain more often have dynapenia and significantly lower velocity of pace that indicates the poor outcome in elderly patients.

Safety of nonsteroidal anti-inflammatory drugs in patients with cardiovascular risk

The review presents current information on the role of NSAIDs in the development of cardiovascular disasters. The development of non-desirable cardiovascular effects and an increase in cardiovascular risk with the administration of NSAIDs, most experts assess in terms of the antagonistic effect on the platelet-vascular homeostasis of metabolites of COX-thromboxane A2 and prostaglandin I2 (prostacyclin). All the presented reviews confirming an increase in the risk of MI complications in the administration of NSAIDs, indicate the class-specificity of this undesirable effect, not homogeneous for different representatives of the group. Important clinical aspects of prescribing NSAIDs for patients with low and moderate cardiovascular risk are the clinical features of the patient and the individual set of risk factors for CVD. Such pharmacokinetic characteristics of NSAIDs as a short half-life, a high degree of binding to blood plasma albumins are indicative of greater safety of NSAIDs, but the final decision must be made based on the accumulated data of clinical trials and meta-analyzes. Keywords: nonsteroidal anti-inflammatory drugs, cardiovascular diseases, cardiovascular risk, lornoxicam, diclofenac sodium, thrombo-elastogram, myocardial infarction, stroke.

Graphene Oxide as a Multifunctional Platform for Intracellular Delivery, Imaging, and Cancer Sensing

Graphene oxide (GO), the most common derivative of graphene, is an exceptional nanomaterial that possesses multiple physical properties critical for biomedical applications. GO exhibits pH-dependent fluorescence emission in the visible/near-infrared, providing a possibility of molecular imaging and pH-sensing. It is also water soluble and has a substantial platform for functionalization, allowing for the delivery of multiple therapeutics. GO physical properties are modified to enhance cellular internalization, producing fluorescent nanoflakes with low (<15%) cytotoxicity at the imaging concentrations of 15 μg/mL. As a result, at lower flake sizes GO rapidly internalizes into HeLa cells with the following 70% fluorescence based clearance at 24 h, assessed by its characteristic emission in red/near-IR. pH-dependence of GO emission is utilized to provide the sensing of acidic extracellular environments of cancer cells. The results demonstrate diminishing green/red (550/630 nm) fluorescence intensity ratios for HeLa and MCF-7 cancer cells in comparison to HEK-293 healthy cells suggesting a potential use of GO as a non-invasive optical sensor for cancer microenvironments. The results of this work demonstrate the potential of GO as a novel multifunctional platform for therapeutic delivery, biological imaging and cancer sensing.

Modulating Chirality-Selective Photoluminescence of Single-Walled Carbon Nanotubes by Ionic Liquids

The chirality-selective near-infrared emission of surfactant-stabilized single-wall carbon nanotubes could be controlled by simply varying the anion of the commonly used 1-butyl-3-methylimidazolium ionic liquids. This result advances the notion of the designer solvent ability of ionic liquids and provides opportunities for modulating the properties of nanomaterials.

Micro-Refractometry and Local-Field Mapping with Single Molecules

The refractive index n is one of the most important materials parameters of solids and, in recent years, has become the subject of significant interdisciplinary interest, especially in nanostructures and meta-materials. It is, in principle, a macroscopic quantity, so its meaning on a length scale of a few nanometers, i.e., well below the wavelength of light, is not clear a priori and is related to methods of its measurement on this length scale. Here we introduce a novel experimental approach for mapping the effective local value [Formula: see text] of the refractive index in solid films and the analysis of related local-field enhancement effects. The approach is based on the imaging and spectroscopy of single chromophore molecules at cryogenic temperatures. Since the fluorescence lifetime T₁ of dye molecules in a transparent matrix depends on the refractive index due to the local density of the electromagnetic field (i.e., of the photon states), one can obtain the local [Formula: see text] values in the surroundings of individual chromophores simply by measuring their T₁ times. Spatial mapping of the local [Formula: see text] values is accomplished by localizing the corresponding chromophores with nanometer accuracy. We demonstrate this approach for a polycrystalline n-hexadecane film doped with terrylene. Unexpectedly large fluctuations of local-field effects and effective [Formula: see text] values (the latter between 1.1 and 1.9) were found.

Use of a glycosamine sulfate for patients with osteoarthritis and a comorbidity with high risk of the side effects from NSAIDS

The literature review is devoted to the peculiarities of treating co-morbid patients with acute conditions of chronic pain. The proved effect of NSAIDS must always correlate with the side effect risk. Patented microcrystalline glucosamine sulfate (pCGS) is likely to have an effect similar to NSAIDS because it can cause decrease of COX-2 and PGE2 gene expression. Randomized trials show, that patented microcrystalline glucosamine sulfate can impede complex structure changes and have a positive effect on the symptoms at the early stage of knee OA. Pharmacokinetic evidence demonstrates that repeated oral intake of microcrystalline glucosamine sulfate can cause the increase of GS in synovial fluid. It is necessary to monitor OA biomarkers during microcrystalline GS treatment, recommend appropriate physical exercise and study the neuropathic component of chronic pain.

Electronic edge-state and space-charge phenomena in long GaN nanowires and nanoribbons

We studied space-charge-distribution phenomena in planar GaN nanowires and nanoribbons (NRs). The results obtained at low voltages demonstrate that the electron concentration changes not only at the edges of the NR, but also in the middle part of the NR. The effect is stronger with decreasing NR width. Moreover, the spatial separation of the positive and negative charges results in electric-field patterns outside the NR. This remarkable feature of electrostatic fields outside the NR may be even stronger in 2D material structures. For larger voltages the space-charge-limited current (SCLC) effect determines the main mechanism of transport in the NR samples. The onset of the SCLC effect clearly correlates with the NR width. The results are confirmed by noise spectroscopy studies of the NR transport. We found that the noise increases with decreasing NR width and the shape of the spectra changes with voltage increase with a tendency toward slope (3/2), reflecting diffusion processes due to the SCLC effect. At higher voltages noise decreases as a result of changes in the scattering mechanisms. We suggest that the features of the electric current and noise found in the NRs are of general character and will have an impact on the development of NR-based devices.

Modifying optical properties of reduced/graphene oxide with controlled ozone and thermal treatment in aqueous suspensions

Graphene possesses a number of advantageous properties, however, does not exhibit optical emission, which limits its use in optoelectronics. Unlike graphene, its functional derivative, graphene oxide (GO) exhibits fluorescence emission throughout the visible. Here, we focus on controlled methods for tuning the optical properties of GO. We introduce ozone treatment of reduced graphene oxide (RGO) in order to controllably transform it from non-emissive graphene-like material into GO with a specific fluorescence emission response. Solution-based treatment of RGO for 5-45 min with ∼1.2 g l^-1 ozone/oxygen gas mixture yields a drastic color change, bleaching of the absorption in the visible and the stepwise increase in fluorescence intensity and lifetime. This is attributed to the introduction of oxygen-containing functional groups to RGO graphitic platform as detected by the infrared spectroscopy. A reverse process: controllable quenching of this fluorescence is achieved by the thermal treatment of GO in aqueous suspension up to 90 °C. This methodology allows for the wide range alteration of GO optical properties starting from the dark-colored non-emissive RGO material up to nearly transparent highly ozone-oxidized GO showing substantial fluorescence emission. The size of the GO flakes is concomitantly altered by oxidation-induced scission. Semi-empirical PM3 theoretical calculations on HyperChem models are utilized to explore the origins of optical response from GO. Two models are considered, attributing the induced emission either to the localized states produced by oxygen-containing addends or the islands of graphitic carbon enclosed by such addends. Band gap values calculated from the models are in the agreement with experimentally observed transition peak maxima. The controllable variation of GO optical properties in aqueous suspension by ozone and thermal treatments shown in this work provides a route to tune its optical response for particular optoelectronics or biomedical applications.

Looking at a blinking quantum emitter through time slots: the effect of blind times

Most experimental observations of physical processes are naturally accompanied by "blind" ("dead") times, which in principle can distort the result of measurements. Here we analyze how the presence of blind times in measurements changes the measured statistics of blinking fluorescence of single quantum dots. We show that information can be extracted even for blinking processes with characteristic times longer than both blind times and time slots between them.

[Current possibilities of correcting subchondral bone resorption as a major pathogenetic factor for progressive osteoarthrosis]

The paper considers the current pathogenesis, by choosing the actual targets of pharmacotherapy with available drugs. It reflects the cytokine mechanisms responsible for lesion of the synovial membranes, cartilage, and subchondral bone. Particular emphasis is laid on the role of chondroitin sulfate, glucosamine, vitamin D3 as drugs that affect the key components of pathogenesis, including the volume of resorptive cavities in the subchondral bone.

Measuring single-walled carbon nanotube length distributions from diffusional trajectories

A new method is demonstrated for measuring the length distributions of dispersed single-walled carbon nanotube (SWCNT) samples by analyzing diffusional motions of many individual nanotubes in parallel. In this method, termed "length analysis by nanotube diffusion" (LAND), video sequences of near-IR fluorescence microscope images showing many semiconducting SWCNTs are recorded and processed by custom image analysis software. This processing locates the individual nanotubes, tracks their translational trajectories, computes the corresponding diffusion coefficients, and converts those values to nanotube lengths. The deduced length values are then compiled into a histogram of lengths present in the sample. By using specific excitation wavelengths and emission filters, this analysis is performed on selected (n,m) structural species. The new LAND method has been found to give distributions in very good agreement with those obtained by conventional AFM analysis of the same samples. Because it is fluorescence-based, LAND monitors only semiconducting, relatively pristine SWCNTs. However, it is less sensitive to artifacts from impurities and bundled nanotubes than AFM or light scattering methods. In addition, samples can be analyzed with less time and operator attention than by AFM. LAND is a promising alternative method for characterizing length distributions of SWCNTs in liquid suspension.

Analyzing absorption backgrounds in single-walled carbon nanotube spectra

The sources of broad backgrounds in visible-near-IR absorption spectra of single-walled carbon nanotube (SWCNT) dispersions are studied through a series of controlled experiments. Chemical functionalization of nanotube sidewalls generates background absorption while broadening and red-shifting the resonant transitions. Extensive ultrasonic agitation induces a similar background component that may reflect unintended chemical changes to the SWCNTs. No major differences are found between spectral backgrounds in sample fractions with average lengths between 120 and 650 nm. Broad background absorption from amorphous carbon is observed and quantified. Overlapping resonant absorption bands lead to elevated backgrounds from spectral congestion in samples containing many SWCNT structural species. A spectral modeling method is described for separating the background contributions from spectral congestion and other sources. Nanotube aggregation increases congestion backgrounds by broadening the resonant peaks. Essentially no background is seen in sorted pristine samples enriched in a single semiconducting (n,m) species. By contrast, samples enriched in mixed metallic SWCNTs show broad intrinsic absorption backgrounds far from the resonant transitions. The shape of this metallic background component and its absorptivity coefficient are quantitatively assessed. The results obtained here suggest procedures for preparing SWCNT dispersions with minimal extrinsic background absorptions and for quantifying the remaining intrinsic components. These findings should allow improved characterization of SWCNT samples by absorption spectroscopy.

[Osteoarthritis and cardiovascular diseases in elderly patients: clinical and pathogenetic interrelationship]

Osteoarthritis (OA) is one of the most common medical conditions in elderly people. This article presents the survey data on a problem of poly-morbidities (co-morbidities) at osteoarthritis. Special attention is paid to a combination of osteoarthritis with cardiovascular pathology, and also the data testifying the association between osteoarthritis and the increased death rate from cardiovascular pathology. On the basis of the literature data analysis a hypothesis about an etiopathogenic interrelation between osteoarthritis and cardiovascular pathology is presented. According to the authors, potential pathogenetic links include a chronic nonspecific inflammation and metabolic infringements. There are also evidences that vascular pathology may initiate and/or worsen the disease progression. The important factors aggravating a current cardiovascular disease in patients with osteoarthritis are: the restriction of physical activities and irrational pharmacotherapy of osteoarthritis clinical symptoms (increased risk of cardiovascular accidents is considered as a class-specific side-effect for all NSAIDs). The authors present the own data on rational pharmacotherapy of patients with osteoarthritis and somatic pathology by means of SYSADOA influencing the disease symptoms and being able to modify structural changes (glucosamine, chondroitine sulphate - ARTRA).

Quantifying the semiconducting fraction in single-walled carbon nanotube samples through comparative atomic force and photoluminescence microscopies

A new method was used to measure the fraction of semiconducting nanotubes in various as-grown or processed single-walled carbon nanotube (SWCNT) samples. SWCNT number densities were compared in images from near-IR photoluminescence (semiconducting species) and AFM (all species) to compute the semiconducting fraction. The results show large variations among growth methods and effective sorting by density gradient ultracentrifugation. This counting-based method provides important information about SWCNT sample compositions that can guide controlled growth methods and help calibrate bulk characterization techniques.

[Toxicological evaluation of chronic exposure to dinil]

Experiments on rats were carried out to study the effect of dinil on the animals on chronic intake of the agent in the quantities exceeding the maximum permissible concentrations by many times. Despite few biochemical changes, there was a certain tension of adaptive processes, which appeared as a change mainly in the integral characteristics of the plasma amino acid pool. The observed changes in the levels of neurotransmitters and neuroactive amino acids in the striatum, midbrain, and hypothalamus are characterized by specific characteristics and may underlie the negative effect of dinil on central nervous system functions. Long-term administration of the agent to the animals did not induce pronounced morphological and biochemical disturbances in the tissues of the liver, heart, and kidneys. Changes in the concentrations of serotonin and neuroactive amine acids in the brain regions might have the greatest consequences to the body. Since the detectable changes in a number of metabolites are likely to be functional in the given period (monthly dinil use), an attempt to correct developing disorders with metabolic therapy agents may be recommended.

Participation of oxygen in the bacterial transformation of 2,4,6-trinitrotoluene

The exposure of Bacillus cereus ZS18 cell suspensions to 2,4,6-trinitrotoluene (TNT) in the absence of other oxidizable substrates increases oxygen uptake, exceeding the basal level of respiration of the bacterium 1.5- and 2-fold with 50 and 100 mg/liter of TNT, respectively. The interaction of both living and to less extent dead bacterial cells with TNT results in the accumulation of superoxide anion (O2*-) in the extracellular medium, which was revealed by the EPR spectroscopy. The accumulation of O2*- decreased by 50-70% in the presence of Cu,Zn-superoxide dismutase of animal origin. In the presence of living bacterial cells, the level of TNT decreased progressively, yielding hydroxylaminodinitrotoluenes together with O2*-. In the presence of heat-killed cells, a moderate decrease in TNT was observed, and the appearance of O2*- was not accompanied by the production of any detectable TNT metabolites. Chelating agents inhibited the transformation of TNT and decreased the formation of O2*-. The demonstrated generation of O2*- during the interaction of TNT with K4[Fe(CN)6] together with the observed effects of chelating agents suggest the participation of iron in the one-electron reduction of TNT and the functioning of an extracellular redox cycle with the involvement of molecular oxygen.

Electric field quenching of carbon nanotube photoluminescence

The effect of external electric fields on the photoluminescence intensity of single-walled carbon nanotubes was investigated for individual nanotubes and bulk samples in polymeric films. Fields of up to 10(7) V/m caused dramatic, reversible decreases in emission intensity. Quenching efficiency varied as the cosine of the angle between the field and nanotube axis and decreased with increasing optical band gap. Photoluminescence intensity was found to follow a reciprocal hyperbolic cosine dependence on electric field.

[Parodontal status distinctive features in patients with the loss of mineral density of peripheral skeleton bone tissue]

According as the loss of mineral bone density (MBD) of peripheral skeleton grows parodontal lesion heaviness increase was demonstrated. Strong negative correlations between API and PBI indices, as well as middle negative correlations between PI index and degree loss of MBD of peripheral skeleton were disclosed. In patients with osteoporosis chronic generalized parodontitis (CGP) was found more frequently when compared with patients not suffering from CGP (41,5 against 12,5% correspondingly).