Chemical Laser Research Articles

Melasma: A Step-by-Step Approach Towards a Multimodal Combination Therapy.

Melasma is a common challenge in the field of pigmentary skin disorders, exerting a significant emotional and psychosocial burden on patients. The persistent and recurring nature of melasma complicates its management in routine clinical practice. This comprehensive review outlines a stepwise, practical approach encompassing diagnostic, preventive and therapeutic strategies for the management of melasma. A thorough exploration of aggravating and exacerbating factors, including sun exposure, hormonal imbalances, photosensitizing medication and cosmetics, is essential for a holistic assessment of the disease. With an emphasis on consistent and effective photoprotection, initial topical treatment modalities target the melanin production and/or the transfer of melanosomes to keratinocytes. Topical tyrosine inhibitors emerge as the first choice for reducing and preventing hyperpigmentation, with compounds such as thiamidol or tranexamic acid (TXA) being preferred for their safety profile over hydroquinone (HQ), kojic acid and arbutin. Combination with chemical peels can further enhance the therapeutic efficacy, even in cases with resistant melasma. In more severe cases, laser- and light-based interventions may be considered, but with the caveat of the likelihood of recurrence within 3-6 months. Assisted TXA delivery, via either fractional non-ablative laser or microneedling techniques, can further improve clinical outcomes. In conclusion, an optimal melasma management strategy is a multimodal approach, which includes effective photoprotection and a mix of different topical treatments targeting melanin synthesis, the anti-inflammatory environment, senescence and vascularity. Complementary procedures, such as chemical peels, and laser, light-based or microneedling procedures, with or without TXA, can further expedite melanin clearance in more severely affected instances. Individual discussions with patients regarding treatment expectations, recurrence likelihood and potential side effects are paramount to a comprehensive and successful therapeutic journey.

Supramolecular salicylic acid combined with niacinamide in chloasma: a randomized controlled trial.

Chloasma is a common skin hyperpigmentation condition, with treatment options ranging from topical agents to advanced interventions such as chemical peels and laser therapy. Salicylic acid, including its supramolecular form (SSA), has shown promise in managing chloasma. However, to date, no multicentre randomized controlled trial of SSA for chloasma is available. The purpose of this study was to assess the efficacy and safety of 30% SSA combined with 10% niacinamide in treating -chloasma. This multicentre (n = 15), randomized, double-blind, parallel placebo-controlled trial (Clinical trial registration number: ChiCTR2200065346) enrolled and randomized 300 participants (1 : 1) to either 30% SSA treatment or placebo, with 150 allocated to treatment and 150 to placebo in the full analysis set, and 144 to treatment and 147 to placebo in the per-protocol set. A Visia® Skin Analysis System was used at each visit to assess the degree of improvement in chloasma lesions. The primary endpoint was the effective rate after 16 weeks, assessed using the modified Melasma Area and Severity Index (mMASI) score [(pretreatment score - post-treatment score)/pretreatment score × 100%]. The total mMASI score, overall score on the Griffiths 10-point scale, and Griffiths 10 score for the left and the right sides of the face were significantly lower in the 30% SSA group than in the placebo group (all P < 0.001). One study of drug-related adverse events (AEs) and one study of drug-unrelated AEs were reported in the 30% SSA group. No AE was reported in the placebo group. Among our patients, 30% SSA combined with 10% niacinamide was shown to be effective and safe for treating chloasma.

POTENTIAL OF NATURAL BIOACTIVE COMPOUNDS IN MANAGEMENT OF MELASMA

Melasma is a form of inherited hyper-melanosis that appears as asymmetrical, brown-colored, uneven, reticulated macules on UVR-exposed skin, particularly on the facial area. The etiopathogenesis of melasma has been linked to several causes, including UV exposure, endocrine factors, genetic predisposition, anti-epileptic medications, and various cosmetics. The initial course of treatment for hyperpigmentation involves applying topical formulations of widely used substances like kojic acid, glycolic acid, and hydroquinone. Pharmaceuticals such as melatonin, tranexamic acid, and cysteamine hydrochloride are administered orally in this process. Chemical peels and laser therapy are examples of second-line therapies that are applied under the direction of trained experts. Unfortunately, these treatments have certain drawbacks and complications, including erythema, dryness, and skin peeling, and they take time to work, necessitating the use of herbal formulations for the management of hyperpigmentation. Bioactive compounds isolated from plants, such as arbutin, aloesin, flavonoids, hesperidin, licorice, ellagic acids, genistein, and quercetin, inhibit melanogenesis without melanocytotoxicity by different mechanisms. This review provides information on natural bioactive compounds used for the management of melasma.

Application of Reactive Bonding Methods on LTCC Substrates

This paper discusses the application of reactive bonding for the area of Low Temperature Cofired Ceramics (LTCC) assemblies. The goal is to reduce the thermal-mechanical stresses during soldering by transferring heat only locally to the solder joints without heating the entire component. Such a reactive multilayer system (RMS) consists of alternating nanolayers (10-300 nm) of at least two metal components which produce an exothermal reaction after ignition. Although the deposition of an RMS is established on silicon substrates for the use in micro-electromechanical systems (MEMS), it is very challenging to create them on LTCC substrates. One of the main obstacles is to overcome all issues connected with the significant roughness, becasue it is not an optimum territory to deposit nanolayers. In this paper, different methods like chemical mechanical polishing (CMP) and laser ablation, to modify the surface morphology, are presented. A direct relation between the morphology and the exothermal reaction can be observed. In addition, 3-D Computational Fluid Dynamics (CFD) simulations were conducted to analyze the process in more detail. These simulations make use of a shoebox model with different layers and an adjustable user-defined function for the heat release of the RMS to adapt the reaction front velocity and the combustion temperature to the experimental values.

Management of Melasma: Laser and Other Therapies-Review Study.

Melasma is a commonly occurring pigmented skin condition that can significantly affect one's appearance, described as symmetric hyperpigmentation that presents as irregular brown to gray-brown macules on various facial areas, such as the cheeks, forehead, nasal bridge, and upper lip, along with the mandible and upper arms. Due to its complex pathogenesis and recurrent nature, melasma management is challenging and the outcomes following treatment are not always deemed satisfactory. Solely treating hyperpigmentation may prove ineffective unless paired with regenerative techniques and photoprotection, since one of the main reasons for recurrence is sun exposure. Hence, the treatment protocol starts with addressing risk factors, implementing stringent UV protection, and then treatment using different strategies, like applying topical treatments, employing chemical peels, laser and light therapies, microneedling, and systemic therapy. This review aims to provide a summary of the effectiveness and safety of the frequently employed laser and light therapies for treating melasma, focusing on laser therapy as a treatment for melasma.

Fluorescent microscopy evaluation of diode laser effect on the penetration depth of turmeric (Curcuma longa) extract cream on skin tissues of Wistar rats.

The study investigates the effect of diode laser exposure on curcumin's skin penetration, using turmeric extraction as a light-sensitive chemical and various laser light sources. It uses an in vivo skin analysis method on Wistar strain mice. The lasers are utilized at wavelengths of 403nm, 523nm, 661nm, and 979nm. The energy densities of the lasers are 20.566J/cm2, 20.572J/cm2, 21.162J/cm2, and 21.298J/cm2, which are comparable to one another. The experimental animals were divided into three groups: base cream (BC), turmeric extract cream (TEC), and the combination laser (L), BC, and TEC treatment group. Combination light source (LS) with cream (C) was performed with 8 combinations namely 523nm ((L1 + BC) and (L1 + TEC)), 661nm ((L2 + BC) and (L2 + TEC)), 403nm ((L3 + BC) and (L3 + TEC)), and 979nm ((L4 + BC) and (L4 + TEC)). The study involved applying four laser types to cream-covered and turmeric extract-coated rat skin, with samples scored for analysis. The study found that both base cream and curcumin cream had consistent pH values of 7-8, within the skin's range, and curcumin extract cream had lower viscosity. The results of the statistical analysis of Kruskal-Wallis showed a significant value (p < 0.05), which means that there are at least two different laser treatments. The results of the post hoc analysis with Mann-Whitney showed that there was no significant difference in the LS treatment with the addition of BC or TEC when compared to the BC or TEC treatment alone (p > 0.05), while the treatment using BC and TEC showed a significant difference (p < 0.05). Laser treatment affects the penetration of the turmeric extract cream into the rat skin tissue.

Laser direct overall water splitting for H2 and H2O2 production

Hydrogen (H2) and hydrogen peroxide (H2O2) play crucial roles as energy carriers and raw materials for industrial production. However, the current techniques for H2 and H2O2 production rely on complex catalysts and involve multiple intermediate steps. In this study, we present a straightforward, environmentally friendly, and highly efficient laser-induced conversion method for overall water splitting to simultaneously generate H2 and H2O2 at ambient conditions without any catalysts. The laser direct overall water splitting approach achieves an impressive light-to-hydrogen energy conversion efficiency of 2.1%, with H2 production rates of 2.2 mmol/h and H2O2 production rates of 65 µM/h in a limited reaction area (1 mm2) within a short real reaction time (0.36 ms/h). Furthermore, we elucidate the underlying physics and chemistry behind the laser-induced water splitting to produce H2 and H2O2. The laser-induced cavitation bubbles create an optimal microenvironment for water-splitting reactions because of the transient high temperatures (104 K) surpassing the chemical barrier required. Additionally, their rapid cooling rate (1010 K/s) hinders reverse reactions and facilitates H2O2 retention. Finally, upon bubble collapse, H2 is released while H2O2 remains dissolved in the water. Moreover, a preliminary amplification experiment demonstrates the potential industrial applications of this laser chemistry. These findings highlight that laser-based production of H2 and H2O2 from water holds promise as a straightforward, environmentally friendly, and efficient approach on an industrial scale beyond conventional chemical catalysis.

Surface wettability modifications and applications in wickless heat pipes

Proper methods of surface fabrication and characterization are essential for various applications. For example, wickless heat pipes, such as flat plate pulsating heat pipes (FPPHP) and a compact flat thermosyphon (CFT), have massive potential for commercialization owing to simple construction, flexibility in using different working fluids, and better thermal contact with flat heat sources. In this work, various surface treatment methods such as chemical etching, electrochemical deposition, and laser texturing on a copper sample are investigated to prepare superhydrophilic or superhydrophobic surfaces, and the thermal durability of the as-prepared surfaces is tested through heating and boiling experiments for 15 days. The wettability modification methods are implemented on the surfaces of the FPPHP and CFT, with the different wettability combinations as either bare evaporator and condenser, completely superhydrophilic (that is, all surfaces including that of evaporator, condenser, and adiabatic section) or completely superhydrophobic or hydrophilic evaporator and superhydrophobic condenser. The thermal performance of the FPPHP and CFT subjected to different wettability combinations on the surface is investigated. Results of FPPHP are reported for water as the working fluid at 60 % filling ratio with power inputs given from 40 to 200 W. Similarly, for CFT, the results are reported for water filled at 50 % filling ratio with heat flux input from 2 to 20 W/cm2. On the FPPHP, the best thermal performance and lowest resistance were obtained when the entire surface was superhydrophilic with a maximum reduction of 60 % at 200 W. The CFT gives the best thermal performance with a bare evaporator and superhydrophobic condenser with a maximum decrease in thermal resistance of 42 % at 20 W/cm2. The best-performing wettability combination for FPPHP and CFT is contrasting and has to be chosen appropriately depending on the heat transfer device.

Investigation on the combustion mechanism for NF3/H2 in DF/HF chemical lasers: a new perspective based on deep potential molecular dynamics simulations.

Combustion-driven deuterium fluoride/hydrogen fluoride (DF/HF) lasers are a crucial type of chemical lasers. Their chemical efficiency mainly depends on the production efficiency of atomic fluorine in the combustion chamber, where NF3 serves as the fluorine resource, and H2 acts as the reducing agent. However, due to the complex combustion process, high reaction temperatures, and potent corrosiveness of the products, the combustion mechanism of NF3/H2 in the combustion chamber is still not fully revealed, including the chemical details of F atom generation. In this work, we firstly employed the molecular dynamics (MD) method to simulate the combustion reaction for combustion-driven DF/HF chemical lasers. Additionally, for the first time, a high-accuracy neural network potential (NNP) for the NF3/H2 system was constructed using machine learning methodologies. The simulation results reveal that the combustion process of the NF3/H2 system comprises three stages: the initiation of combustion, the generation of HF, and the formation of N2. The fluorine atoms in the system primarily originate from the cleavage of the N-F bond in N2F4, which is formed via the dimerization of NF2. Temperature and molar ratios of reactants are two important factors influencing the F atom formation. Higher temperatures and an excess number of NF3 favor the generation of F atoms. Besides, we found that the initial HF production stems from H-abstraction reaction between the F radical and H2, rather than the previously proposed reaction between NF3 and H2. The NNP-based MD simulations unveil the atomic-scale reaction mechanisms for NF3/H2 combustion in combustion-driven DF/HF chemical lasers, indicating its potential as an effective tool for the studies in the field of chemical lasers. The results also offer theoretical insights for enhancing the performance of the combustion-driven DF/HF chemical lasers.

Perceptions, Utilization, and Cost Assessment of Sebaceous Hyperplasia Treatment Modalities: A Pilot Survey.

Sebaceous hyperplasia (SH) is a common, benign but cosmetically bothersome skin condition preferentially affecting older adults. Despite multiple treatment options, there is no universally accepted first-line treatment for SH nor standard pricing for said approaches.&nbsp; Methods: A survey aimed at evaluating treatment approaches and their respective costs was disseminated on the Orlando Dermatology Aesthetic and Clinical Conference email listserv.&nbsp; Results: Out of 224 dermatologists who participated in the survey (response rate 9.2%), most treated patients with SH (95.98%). In-office procedures were used more than pharmacologic treatments (P=&lt;0.05). Treatments most used by respondents included electrodesiccation (ED; 83.9%), cryosurgery (35.3%), oral isotretinoin (32.6%), and carbon dioxide (CO2) laser (19.2%). Cryosurgery and ED priced between &lt;$200 to $400. Most reported 1 to 2 sessions to achieve lesion clearance for ED, CO2 laser, and cryosurgery. Twenty-one percent reported 3-4 sessions with cryosurgery. Chemical peels, diode lasers, and photodynamic therapy required between 2-4 sessions. Respondents indicated lesions were most unlikely to recur with ED and CO2 laser. Most dermatologists (86.39%) agreed or strongly agreed that they were exposed to new treatments methods for SH through this survey and 86.49% of dermatologists were interested in learning about treatments employed by others. SH is a common issue that presents in the dermatologist's office. These data highlight the perception that ED is the most common approach employed, associated with lower costs, and requiring fewer sessions to achieve resolution. More data is needed and wanted to better determine best practices for the management of SH.J Drugs Dermatol. 2024;23(2):29-37.&nbsp; doi:10.36849/JDD.7734.

Optimized laser photoionization scheme of separation of complex isotopes in the separator devices

An effective approach to determining parameters of optimal schemes of the method of laser selective photoionization of heavy isotopes, in particular, lanthanides (Gd atoms as the example) with ionization at the final stage by a pulsed electric field, autoionization through the narrow autoionization resonances and due to collisions is developed for separation of heavy isotopes in the separator devices. On the basis of the theory of optimal control and previously developed theoretical quantum approaches (the energy formalism and the relativistic many-body perturbation theory with the Dirac-Kohn-Sham-Sturm zeroth approximation for computing the parameters of elementary atomic processes such as excitation, ionization amplitudes, cross-sections, energies, widths of autoionization resonances etc.) an optimized scheme for the separation of Gd isotopes by the method of 3-stage laser photoionization with ionization at the final stage by a pulsed electric field, ionization through narrow autoionization resonances is presented. For the first time, there are theoretically calculated parameters of the narrow autoionization resonances for Gd in a sufficiently weak electric field, which are in physically reasonable agreement with data of the known experiment by Letokhov et al. Narrow-width autoionization resonances in Gd (in general in spectra of any lanthanide &amp; actinide atom) have a relatively long lifetime, correspondingly, their excitation, ionization cross sections have the same order as the excitation one at the initial stage of separation scheme. Therefore, the use of these long-lived states can ensure the optimal implementation of a laser scheme for the separation of heavy isotopes. The obtained results for Gd with using models of optimal governing confirm the perspective of construction of the optimized schemes of the laser photoionization method with ionization at the final stage by a pulsed electric field, autoionization and allow determining the optimal parameters of the separation scheme, including diagram of atomic transitions, shape of laser pulses, etc. It is hoped that this work will also provide new opportunities for further development of laser chemistry of lanthanides, as well as actinides, taking into account new physics of autoionization resonances in their spectra.

A New Method for Magnetic Gain Modulation of Chemical Oxygen Iodine Laser Based on Flat-Top Pulsed Magnetic Field

A New Method for Magnetic Gain Modulation of Chemical Oxygen Iodine Laser Based on Flat-Top Pulsed Magnetic Field

Growth, spectroscopy properties and laser operation of a novel single crystal fiber: Nd3+-doped CaY0.9Gd0.1AlO4

A Nd3+-doped CaY0.9Gd0.1AlO4 single crystal fiber (Nd: CYGA SCF) with a length of 80 mm and a diameter of 1 mm, to the best of our knowledge, was successfully grown for the first time by a highly efficient laser-heated pedestal growth method. The basic physical and chemical properties, optical properties, and laser properties of the as-grown SCF were studied in detail. The results show that the Nd: CYGA SCF has wider absorption and emission half-peak full width compared with a bulk single crystal. Furthermore, under the pumping of a commercial 808 nm laser diode, a CW laser operation at 1080 nm with a half-height width of 0.29 nm was obtained. The laser output power was 54 mW at an absorbed power of 2.03 W. The slope efficiency was 6.79% with respect to the absorbed pump power. Thus, the Nd: CYGA SCF might be a practical and powerful candidate for laser gain medium, and have a great research space in the field of lasers.

Comparative Study of Polydioxanone Monofilament (PDO) Threads Combined with Scar Subcision versus Fractional CO2 Laser Combined with Scar Subcision in Management of Atrophic Post Acne Scars

Abstract Background Acne is an inflammatory disorder of the pilosebaceous unit characterized by comedones, inflammatory papules, pustules, and nodules of the face, chest, and back. The inflammatory response in some acne patients results in permanent, disfiguring scars from either increased tissue formation or due to loss or damage of tissue. Many treatments have been attempted in order to improve acne scarring such as: chemical peels, surgical excision, subcision, punch grafting, dermabrasion, fillers and laser have been used to ameliorate atrophic acne scars with varying degrees of success Objectives The aim of this work was to study the efficacy of polydioxanone (PDO) monofilament threads combined with scar subcision versus fractional Co2 laser combined with scar subcision in management of atrophic acne scars. Patients and Methods This is a split-face pilot study included 10 patients with atrophic acne scars. The patients recruited from the Outpatient Dermatology Clinic at Ain Shams University Hospitals. Fractional CO2 laser sessions were done for the right side of the face (2 sessions - one month apart), and Polydioxanone (PDO) threads were inserted to the left side of the face (2 sessions - one month apart), each treatment modality was preceded by scar subcision. The patients were followed up for 3 months. The response of treatment was evaluated by Antera 3D camera. Results Our study revealed that treatment of the right side of the face with fractional CO2 Laser led to statistically significant improvement more than what was achieved by PDO threads on the left side. It was also found that both PDO monofilament threads and Fractional Co2 laser improved the skin texture. Conclusion .The current study confirmed the superiority of fractional CO2 laser for the management of atrophic post acne scars. Polydioxanone threads had an effect in improving the skin texture but their overall effect is not comparable to the effect of fractional CO2 laser. To the best of our knowledge, we were the first to compare between Fractional Co2 laser and poydioxanone threads regarding there efficacy in management of atrophic acne scars and to evaluate the response using Antera 3D camera.

High-Temperature Energy Storage Properties of Bi0.5Na0.5TiO3-0.06BaTiO3 Thin Films

Bi0.5Na0.5TiO3-0.06BaTiO3 (BNT-BT) thin films were prepared via both chemical solution (CSD) and pulsed laser deposition (PLD). The structural, dielectric, and ferroelectric properties were investigated. High stability of the dielectric permittivity or TCC (∆ε/ε (150 °C) ≤ ±15%) over a wide temperature range from room temperature to 300 °C was obtained. Distinctly, the CSD film showed high TCC stability with variation of ±5% up to 250 °C. Furthermore, the CSD film showed an unsaturated ferroelectric hysteresis loop characteristic of the ergodic relaxor phase. However, the PLD one exhibited an almost saturated loop characteristic of the coexistence of both ergodic and non-ergodic states. The energy storage properties of the prepared films were determined using P–E loops obtained at different temperatures. The results show that these films exhibited a stable and improved energy storage density comparable to ceramic capacitors. Moreover, the CSD film exhibited more rigidity and better energy storage density, which exceeded 1.3 J/cm3 under a weak applied field of 317 kV/cm, as well as interesting efficiency in a large temperature range. The obtained results are very promising for energy storage capacitors operating at high temperatures.

Dynamic Formation of Green Tea Cream and the Identification of Key Components Using the "Knock-Out/Knock-In" Method.

The composition of green tea cream is extremely complex, and identification of key components is a prerequisite for elucidating its microstructure formation mechanism. This study examined the dynamic changes in the content of components and properties of colloid particles during the formation process of tea cream by chemical analysis and dynamic laser scattering (DLS). A "knock-out/knock-in" method was developed and used to further explore the relationship between the interaction of these components and the microstructure formation of tea cream. The results revealed that polysaccharides, proteins, epigallocatechin gallate (EGCG), and caffeine were the main components involved in tea cream formation. These components participated in the formation process in the form of polysaccharide-protein and EGCG-caffeine colloidal particles. Consequently, there were synchronized dynamic changes in the levels of polysaccharides, proteins, EGCG, and caffeine. The "knock-out/knock-in" experiment revealed that the interactions between EGCG or caffeine and macro-molecule components were not the key factors in tea cream microstructure formation. However, it was found that the complexation between EGCG and caffeine played a crucial role in the formation of tea cream. The findings suggested that decreasing the concentrations of EGCG and caffeine could be useful in controlling tea cream formation during tea beverage processing and storage.

KHg4Ga3S9: A Hg-Based Sulfide with Nonlinear-Optical Activity in the A-MII-MIII-Q (A = Alkali Metal; MII = d10 Metal; MIII = Ga, In; Q = S, Se) System.

The search for new high-performance infrared (IR) nonlinear-optical (NLO) materials is a hot topic in the fields of laser chemistry and inorganic solid-state chemistry. Here, a new Hg-based sulfide KHg4Ga3S9 in the family of A-MII-MIII-Q (A = alkali metal; MII = d10 metal; MIII = Ga, In; Q = S, Se) was synthesized. It crystallizes in the orthogonal system of the C2221 structure, which is rare for IR NLO chalcogenides. Its anionic framework {[Hg4Ga3S9]-}∞ is constructed by two types of interconnected helical chains, viz., the inner layer ({[Hg6Ga2S29/3]4/3-}∞) and the outer layer ({[Hg2Ga4S25/3]2/3-}∞). It exhibits a moderate NLO response and a high laser-induced damage threshold. Theoretical calculations indicate that the HgS4 unit accounts for its much larger NLO response compared to RbCd4Ga3S9. The influence of alkali metals and d10 metals on the initial phase-matching wavelength is also discussed. This work provides inspiration for improving the properties of NLO materials' properties.

Carbon nano-onion as next-generation functional nanomaterial: Synthesis methods and practical applications

Carbon nano-onion (CNO) (also known as onion-like carbon, OLC), exhibiting multiple enclosed fullerene shell structures, as one of the most promising nanoforms, has attracted worldwide attention during the past decades due to its exceptional chemical and physical properties such as non-toxicity, high chemical stability, large sufficient surface area with low density, and superior high electronic and thermal conductivities, visible photoluminescence, etc. Nowadays, functional CNOs have been applied in energy storage devices, supercapacitors, photovoltaics, light-emitting diodes and bio-imaging technology. Since the first observation of CNOs by transmission electron microscopy as a byproduct in the synthesis of carbon black in 1980, numerous experimental and theoretical studies including expressive practical applications of CNOs have been intensively developed in modern chemistry. With respect to synthetic techniques, the high-temperature annealing of nano diamond, detonation of high explosive molecules, arc discharge of graphite, chemical vapor deposition, laser ablation, thermal pyrolysis, hydrothermal carbonization, and microwave pyrolysis have been reported. It has been addressed that the synthesis approach plays a key role in determining the structure of CNOs and resultant properties. This paper reviewed the developments of CNOs through major synthesis methods utilized for a selected wide spectrum of applications, by covering both the past and current progress. The contents outlined in the current review will offer readers comprehensive insights into the design and development of CNO materials.

Modern approaches to the correction of age-related skin changes in women

The article is devoted to the literature review on the correction of age-related skin changes in women. Skin aging is a physiological process that is caused by the constant action of unmodified factors, for example, endocrine disorders, shortening of telomeres, etc., in combination with periodic influence of modified (exposomal) factors. Ultraviolet radiation takes first place among external factors affecting the progression of degenerative changes in skin, however, in women, involutional changes in skin are primarily associated with a fading of synthetic function of ovaries. During the first five years from the onset of menopause, content of collagen fibers I and III types is reduced by 30% in combination with a further reduction of 2% annually for the next 15 years.Involutive transformations occur in all layers of skin and are visually characterized by the presence of wrinkles, roughness of the epidermal surface (with photoaging) or a decrease in its thickness (with chronic aging), dryness, pigmentation disorders in the form of uneven hyperpigmented spots, telangiectasias, oval deformations.Today, there are many methods of aesthetic correction of age-related skin changes. In the arsenal of a cosmetologist there are both invasive (PRP-therapy, microneedling, microneedle radio wave lifting, administration of preparations based on calcium hydroxyapatite, polylactic and hyaluronic acid, etc.) and minimally invasive (administration of botulinum neuroprotein, application of chemical acid peelings, IPL-therapy and laser polishing, photodynamic therapy) methods. Patients prefer minimally traumatic procedures due to the fact that they almost do not disturb the processes of socialization, however, each of these methods has both advantages and disadvantages.Modification of a woman life quality in peri- and menopause in form of changes in lifestyle and eating behavior, increasing physical activity, quitting smoking and limiting the use of alcoholic beverages is an integral part of therapeutic care. However, the appointment of menopausal hormonal therapy, including the use of estrogens, progestogens and combined hormonal drugs, allows to achieve a stable and long-lasting effect from cosmetology procedures and home care.

Minimally invasive treatment of pilonidal sinus disease (a systematic review and meta-analysis)

AIM: to estimate the effectiveness of minimally invasive methods for treatment of chronic inflammation in pilonidal sinus disease by systematic review.PATIENTS AND METHODS: fifty-two clinical trials were selected from 2,576 papers in databases for systematic review. It included the following methods: the fibrin glue, the sinusectomy, the video-assisted pilonidal sinus treatment, the laser coagulation and the chemical destruction using crystallized phenol or its solution. Regarding the last two methods, a meta-analysis was carried out.RESULTS: the meta-analysis demonstrated the high effectiveness of phenol and laser coagulation for pilonidal sinus disease. When comparing the results of phenol use and excisional techniques, there was a significant difference in higher frequency complications rate after excisional techniques (HR 0.42; 95% CI: 0.05–3.71), while the recurrence rate was the same (HR 0.98; 95% CI: 0.45–2.16). The probability of recurrence was significantly higher than after excision techniques in compare with SiLaC (HR 4.02; 95% CI: 1.13 14.3, p = 0.03). However, there was no significant differences in complication rate after SiLaC and excisional techniques (HR 0.63; 95% CI: 0.29–1.34).CONCLUSION: the chemical destruction and laser coagulation are the most effective methods for pilonidal sinus treatment.