Appearance Of Dark Spots Research Articles

Pilot Clinical Safety and Efficacy Evaluation of a Topical 3% Tranexamic Acid Cream and Serum Protocol for Managing Facial Hyperpigmentation in Caucasian Patients

Facial hyperpigmentation is a highly prevalent dermatological condition, characterized by dark spots on the skin resulting from excess melanin production. Hyperpigmentation significantly impacts patients’ quality of life and self-esteem. Current treatments often present disadvantages linked to poor product tolerability. A topical cosmetic approach combining three lightening active ingredients (tranexamic acid, niacinamide, vitamin C) offers a new option for treating dark spots on the skin. The present in-use test under dermatological control evaluated the clinical safety and efficacy of a cream and serum containing these three ingredients, formulated with hyaluronic acid for enhanced delivery, stability, and efficacy. A total of 22 Caucasian patients with facial hyperpigmentation, both male and female, aged between 45 and 67 years, applied the cream and serum for 8 weeks. Clinical assessments, colorimetric evaluations, standardized photography, and self-assessment questionnaires were used to measure outcomes. No serious adverse effects were recorded, and the incidence of local adverse effects was low, highlighting good tolerability of the investigated test items. In most participants, significant improvements in hyperpigmented areas were recorded. Clinical scoring by the dermatologist investigator indicated a statistically significant 13% reduction in color intensity and a 6% reduction in the size of dark spots after 8 weeks of treatment. Colorimetric evaluation showed a statistically significant 1% increase in luminosity (L* parameter) and an 8% improvement in the Individual Typological Angle (ITA°) in endpoint, indicating lighter skin spots. Subjective assessments reflected high user satisfaction, with 95% of participants noting improvements in skin hydration and luminosity, and 77% reporting a reduced appearance of dark spots. Overall, the present work supports the use of tranexamic acid, niacinamide, and vitamin C as an effective and well-tolerated combined topical management option for hyperpigmentation. This combination offers a viable alternative to classical whiteners for individuals seeking to reduce facial skin coloration imbalance and improve skin tone.

Insights into the interaction between defrosting seasonal ices and gully activity from CaSSIS and HiRISE observations in Sisyphi Cavi, Mars

Martian gullies are surface features, typically composed of an alcove, a channel and a depositional apron. They have been extensively studied since their first observations in the 2000s and were initially attributed to the action of liquid water. Later studies highlighted that their activity is spatially and temporally correlated with the seasonal presence of surface CO2 ice, suggesting a link between seasonal frost and gully activity. However, the exact mechanisms leading to gully formation are still under debate. Establishing whether or not gullies are formed by liquid water has important implications for Mars recent climate and habitability. Here, we study the evolution of seasonal frost and its connection to gully activity in Sisyphi Cavi, located in the southern circumpolar region (68°S - 74°S; 345°E − 5°E). The high latitude of this site allows for detailed temporal monitoring, owing to the high frequency imaging by spacecraft in polar orbits, largely unavailable for other martian gullies, hence this site has the potential to reveal new insights on gullies in general. In particular, we used repeat images from MRO HiRISE (Mars Reconnaissance Orbiter, High Resolution Imaging Science Experiment) and TGO CaSSIS (Trace Gas Orbiter, Colour and Stereo Surface Imaging System). Our findings show that the general timing and characteristics of the defrosting patterns in Sisyphi Cavi follow seasonal patterns that are consistent from year to year. The timing of the start of defrosting and its temporal evolution are controlled by the overall orientation of the host hillslope, with equator-facing slopes defrosting before pole-facing ones and the steepest pole-facing slopes defrosting last. Gully alcoves defrost before channels and aprons located on the same hillslope independent of the orientation of the hillslope likely because the aprons have a lower thermal inertia than the alcoves that counteracts the orientation effect, which on pole-facing slopes would mean the alcoves should defrost last. We observe the presence of seasonal and ephemeral dark spots and flows which are interpreted to be a result of sediment deposition on top of the seasonal ice deposits, triggered by basal sublimation. Our observations suggest that the appearance of dark spots and dark flows can be spatially correlated with surface roughness, including presence of boulders, contrasts in material types, irregular lobes/levees and braiding caused by gully activity, and therefore could be used to help detect recently active gullies on Mars in areas with seasonal frost without the need of repeat imaging. Finally, we propose that presently observed gully activity in Sisyphi Cavi is driven by defrosted material flowing on to a frosted apron. We infer that the presence of a frosted apron could be common precursor for this type gully activity. We note that this activity only involves the mobilisation of loose materials and we have not observed any erosion of the wall rock present in Sisyphi Cavi.

Preparation and Evaluation of Herbal Nutmeg Night Face Cream

Abstract: The spice known as nutmeg is manufactured from the seeds of the tropical evergreen tree Myristica fragrans (family Myristicaceae). Nutmeg is used to flavour a variety of baked items, confections, puddings, potatoes, meats, sausages, sauces, vegetables, and beverages like eggnog. It has a distinctly pungent scent and a toasty, somewhat sweet taste. Nutmeg is believed to have antibacterial, anti-inflammatory, and antioxidant properties, which could help to improve the overall health and appearance of the skin. Nutmeg cream is often used to address issues such as acne, inflammation, and signs of aging. It may also help to improve skin texture and tone, as well as reduce the appearance of dark spots and blemishes. Spreadability of the developed formulation was good. The cream's PH and viscosity were both good. During storage, cream doesn't exhibit any phase separation of any kind.

Corrosion effects in bifacial crystalline silicon PV modules; interactions between metallization and encapsulation

This study addresses the influence of different encapsulation materials on performance losses in bifacial PV modules after extended damp heat testing. The widely used ethylene vinyl acetate (EVA) is compared to polyolefin elastomers (POE) and thermoplastic polyolefins (TPO). We show that modules based on n-type bifacial solar cells (tunnel oxide passivated contact, TOPCON) are more prone to degradation than p-type (Passivated emitter rear cell, PERC) based laminates. More specifically, the front side metallization of these n-type cells corrodes under extended damp heat testing, yielding a decreased fill factor in the I–V characteristics and the appearance of dark spots and dark areas in electroluminescence imaging. The newer generation of encapsulant materials (POE and TPO), slowly replacing EVA in the modules commercialized today, demonstrate an improved protection of the metallization. Apart from the nature of the encapsulant, the cell type and the presence or absence of glass cover plates are also shown to influence the metal grid corrosion. To better understand the mechanisms at play, post-mortem analysis was carried out on small sized degraded PV laminates, by drilling out circular samples (“coring”) that could be analyzed in depth. The analyses revealed a weakened bond between the metallization and the silicon emitter, ultimately causing metal grid delamination. The proposed mechanism behind this delamination starts with the degradation of lead glass, which is part of the cell metallization grid and contains lead oxide (PbO). This compound is susceptible to dissolution in acidic environment.

TEM Study of Irradiated PVC Embedded with Tin Complexes of Heterocyclic and Aromatic Moieties

Poly(vinyl chloride) (PVC) could be considered as one of the highly manufactured plastics with a production capacity of multiple millions tons per year. Fillers are recently added to PVC in an attempt to increase its applications in various sectors, especially at tough exposing conditions. Therefore, the current work reports the morphological studies of PVC sheets that contain trimethoprim-tin complexes as additives. The PVC was blended with a low concentration of trimethoprim-tin complexes and thin films have been prepared from the homogenous mixtures. The ultraviolet irritation impact on the morphology and physicochemical properties of the films was studied. It was found that the photodecomposition and photo-oxidation levels of PVC films were lower than the blank film’s ones. The TEM images showed that the undesirable changes in the surface of irradiated PVC films, such as the appearance of dark spots, cracks, and roughness, were minimized once the tin complexes were filled compared with the blank PVC.

666 Human skin ethnicity: Contribution of tissue engineering to develop cosmetic ingredients

Recent publications describe various skin disorders in relation with phototypes and aging. The highest phototypes (III to VI) are more sensitive to acne with the appearance of dark spots due to the inflammation induced by Cutibacterium acnes (previously named Propionibacterium acnes). Ethnic variations of skin dryness with aging due to a lower activity of specific enzymes involved in the maturation of lipids of the stratum corneum were also reported. To observe and understand these cutaneous disorders, tissue engineering is a perfect tool.

Brief review on herbal lipsticks using natural colorants over synthetic colorants

Nowadays herbal lipsticks are gaining popularity because natural cosmetics are safe to use. Synthetic coloring agents may cause allergic reactions and are found to be carcinogenic. We will study how the coloring matter from natural sources such as beetroot, grapes, blueberry, papaya, tomato, strawberry, watermelon, pomegranate, etc is beneficial over synthetic colorants in the preparation of lipsticks.Natural ingredients such as beeswax, carnauba wax, white soft paraffin, vanilla essence, castor oil, and vitamin E formulate herbal lipstick. Natural colorants in cosmetics also show different activities such as anti-anti-cancer, anti-oxidant, anti-microbial, anti-inflammatory, rich in vitamins, reducing the appearance of dark spots, fine lines, and wrinkles, and protecting from UV radiation, etc.

Preparation, Characterization, and Surface Modification of Cellulose Nanocrystal from Lignocellulosic Biomass for Immobilized Lipase

This study reports the synthesis of cellulose nanocrystal (CNC) from sugarcane bagasse and rice straw as the matrix for immobilized lipase enzyme. The CNC surface was modified using cetyltrimethylammonium bromide (CTAB) to improve the interaction of CNC with glutaraldehyde so that CNC can immobilize lipase effectively. The results showed that after surface modification of CNC using CTAB with concentrations of 2–10 mM, the crystallinity of CNC slightly decreased. The presence of immobilized lipase on the modified CNC was confirmed visibly by the appearance of dark spots using transmission electron microscopy (TEM). The bond formed between the enzyme and CNC was approved using Fourier transform infrared spectroscopy (FTIR). FTIR results show a new amine group peak in the immobilized lipase, which is not present in the modified CNC itself. The modified CNC, both from bagasse (SB-20 A1-1) and rice straw (RS-20 B1-1), was successfully applied to the immobilized lipase enzyme with a yield of 88%. The observed free enzyme activity was 3.69 µmol/min∙mL. The degree of hydrolysis of canola oil relative to free lipase (100%) from immobilized lipase at lipase SB-20 A1-1 and lipase RS-20 A1-1 was 23% and 30%, respectively. Therefore, this study successfully immobilized lipase and applied it to the hydrolysis of triglycerides.

Addressing Human Skin Ethnicity: Contribution of Tissue Engineering to the Development of Cosmetic Ingredients

Recent publications describe various skin disorders in relation to phototypes and aging. The highest phototypes (III to VI) are more sensitive to acne, with the appearance of dark spots due to the inflammation induced by Cutibacterium acnes (previously Propionibacterium acnes). Dryness with aging is due to a lower activity of specific enzymes involved in the maturation of lipids in the stratum corneum. To observe and understand these cutaneous issues, tissue engineering is a perfect tool. Since several years, pigmented epidermis with melanocytes derived from specific phototypes allow to develop in vitro models for biological investigations. In the present study, several models were developed to study various skin disorders associated with phototypes and aging. These models were also used to evaluate selected ingredients’ ability to decrease the negative effects of acne, inflammation, and cutaneous dryness. Hyperpigmentation was observed on our reconstructed pigmented epidermis after the application of C. acnes, and pollutant (PM10) application induced increased inflammatory cytokine release. Tissue engineering and molecular biology offer the capability to modify genetically cells to decrease the expression of targeted proteins. In our case, GCase was silenced to decrease the maturation of lipids and in turn modify the epidermal barrier function. These in vitro models assisted in the development of ethnic skin-focused cosmetic ingredients.

Effect of Ultraviolet Irradiation on Polystyrene Containing Cephalexin Schiff Bases.

The scale of production of polystyrene has escalated in the recent past in order to meet growing demand. As a result, a large quantity of polystyrene waste continues to be generated along with associated health and environmental problems. One way to tackle such problems is to lengthen the lifetime of polystyrene, especially for outdoor applications. Our approach is the synthesis and application of new ultraviolet photostabilizers for polystyrene and this research is focused on four cephalexin Schiff bases. The reaction of cephalexin and 3-hydroxybenzaldehyde, 4-dimethylaminobenzaldehyde, 4-methoxybenzaldehyde, and 4-bromobanzaldehyde under acidic condition afforded the corresponding Schiff bases in high yields. The Schiff bases were characterized and their surfaces were examined. The Schiff bases were mixed with polystyrene to form homogenous blends and their effectiveness as photostabilizers was explored using different methods. The methods included monitoring the changes in the infrared spectra, weight loss, depression in molecular weight, and surface morphology on irradiation. In the presence of the Schiff bases, the formation of carbonyl group fragments, weight loss, and decrease in molecular weight of polystyrene were lower when compared with pure polystyrene. In addition, undesirable changes in the surface such as the appearance of dark spots, cracks, and roughness were minimal for irradiated polystyrene containing cephalexin Schiff bases. Mechanisms by which cephalexin Schiff bases stabilize polystyrene against photodegradation have also been suggested.

Effective removal of volatile organic compounds (VOCs) in a sealed device: a case study for LED bulbs

It is known that Volatile Organic Compounds (VOCs) can be generated by components in electronic devices during their operative service life with consequent detrimental effects. In particular, for opto-electronic devices such as sealed LED lamps and laser diodes where an intense optical flux is in place, it was already reported the appearance of dark spots onto emitting area as effect of pyrolysis of carbonaceous gaseous species within the package. In the present paper we present a novel solution to contrast VOCs-induced degradation in hermetically sealed devices, based on a proprietary composition that combines positive and synergic effects of both Getter and Dispenser (GaD) materials. In particular, we describe the fundamental action mechanisms and the criteria for GaD design. We demonstrate GaD effectiveness in a real operating system, extending the effective service life from few hundred hours to several thousand hours.

New topical tranexamic acid derivative for the improvement of hyperpigmentation and inflammation in the sun-damaged skin.

Skin-lightening products are used worldwide to treat persistent pigmentation disorders that impact our quality of life and self-confidence. However, consumers of cosmetic and over-the-counter skin lighteners struggle to find products that perform to their expectations. New, safe, and effective bioactives are needed to fill this gap. To investigate the safety and skin-lightening performance of a new topical tranexamic acid derivative, that is, cetyl tranexamate mesylate. The test material was a facial serum containing 2.0% (w/w) of the new bioactive. Safety was evaluated by a modified Human Repeat Insult Patch Test with 54 subjects of either sex. Performance was objectively assessed based on the improvement of melanin and erythema indexes through time, and also subjectively by photographs and self-perception questionnaires. Thirty-five female subjects applied the serum twice a day for 8weeks. No questionable adverse reactions were observed. Melanin and erythema indexes improved significantly and continuously from the baseline to the end of the study (-16.9% and -34.3%, respectively). Photographs further support instrumental data. On average, after 2weeks, the subjects already noticed an improvement in skin tone (79.3%), a reduction in dark spots (78.6%), and an improvement in facial redness (77.1%). A topical serum containing cetyl tranexamate mesylate was well-tolerated and successfully improved the overall facial skin tone, as well as the appearance of dark spots and redness.

Electrical and Environmental Degradation Causes and Effects in Polyfluorene-Based Polymer Light-Emitting Diodes

We report on the degradation mechanism of polymer light-emitting diodes (PLEDs) kept in the environment with no encapsulation. The device structure is indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS)/polyfluorene/aluminum (Al) fabricated by a simple solution-processed method. Its physical, optical and electrical properties were measured over time in order to explore factors resulting in device instability. The sustained decrease in current density and electroluminescence, as well as the appearance of dark spots and electrode delamination, reveal that the device performance tends to degrade in the atmosphere gradually. To clarify the effect of the external electric field on the device degradation process, a device with lower threshold voltage was fabricated and its performance was recorded with and without bias voltage. Also, when the Al cathode of a completely ruined blue PLED was re-deposited, the device started to emit green light, confirming the irreversible chemical structural changes occurred in the active layer. Noticeably, in addition to cathode delamination, we observed that the rate of luminescence degradation in fabricated PLEDs is more than two times faster than that of the current density. The detailed study of the stability issue in PLEDs, presented in this work, can have great potential importance in the fabrication of other organic electronic devices such as organic solar cells and organic photodetectors due to similar instability factors.

Distinction and characterisation of rice genotypes tolerant to combined stresses of salinity and partial submergence, proved by a high-resolution chlorophyll fluorescence imaging system.

Chlorophyll a fluorescence (ChlF) parameters measured with fluorescence imaging techniques were used to investigate the combined effect of salt and partial submergence stress to understand photosynthetic performance in rice (Oryza sativa L.). ChlF parameters such as maximal fluorescence (Fm), variable fluorescence (Fv=Fm -F0), the maximal photochemical efficiency of PSII (Fv/Fm) and the quantum yield of nonregulated energy dissipation of PSII (Y(NO)) were able to distinguish genotypes precisely based on their sensitivity to stress. Upon analysis, we found the images of F0 were indistinguishable among the genotypes, irrespective of their tolerance to salt and partial submergence stress. On the contrary, the images of Fm and Fv/Fm showed marked differences between the tolerant and susceptible genotypes in terms of tissue greenness and the appearance of dark spots as stress symptoms. The images of effective PSII quantum yield, the coefficient of nonphotochemical quenching (qN) and the coefficient of photochemical quenching (qP) captured under different PAR were able to distinguish the tolerant and susceptible genotypes, and were also quite effective for differentiating the tolerant and moderately tolerant ones. Similarly, the values of electron transport rate, qN, qP and Y(NO) were also able to distinguish the genotypes based on their sensitivity to stress. Overall, this investigation indicates the suitability of chlorophyll fluorescence imaging technique for precise phenotyping of rice based on their sensitivity to the combined effect of salt and partial submergence.

A Study of Structural Changes in Pressed Semiproducts from Aluminum Alloy V95ochT2 in the Range of Dark Spots

Seven heats of alloy V95ochT2 are studied after a heat treatment imitating the conditions of the appearance of dark spots in the production process and anodic oxidizing (anodizing). The mechanical properties, the hardness, the structure, and the electrical conductivity of the alloy are determined. The causes and conditions of the appearance of dark spots are analyzed. The transparence of the film is shown to worsen upon formation of particles of second phase in the alloy.

Postmortem MRI Changes of the Brains of the Rats of Different Ages

Brain degenerative changes were studied in the rats of different ages after cervical dislocation by T2 MRI and histology. Appearance of dark spots in the T2 images increased with increased duration after death. Quantitative analysis of the density of these spots revealed that the neonatal (1 week) and the old (9 months) animals had accelerated degenerative changes when compared with the young adult (1 month). The degenerative changes correlated with the accumulation of vacuoles or spaces in the brain tissue histologically. This study pointed out not only brain degenerative changes after death were associated with age, it also revealed that the MRI T2 evaluations could be used as a way in postmortem investigation.

有機電界発光デバイス用フィルム保護膜の開発

This review paper describes the present status of passivation films with organic/Inorganic multilayer structure on flexible organic film substrate designed for electronic devices such as organic light emitting diode (OLED). Passivation film of SiNx/CN:H multilayer showed an excellent barrier properties for water and oxygen and strongly suppressed an appearance of dark spots on OLED surface during operation. The luminous efficiency of flexible OLED thus formed with passivation films revealed to be equivalent to that on glass substrate encapsulated by can. substrate.

Field-enhanced photodegradation of pyrromethene dye films

The photodegradation of pyrromethene films, neat and polymer-dispersed, is investigated by measuring the relative photocarrier yield as a function of accumulated 532 mm laser pulses. The rate of reduction in photocarrier production is compared for samples irradiated in the absence and presence of an electric field by utilizing a delayed-photocurrent collection method. Higher bias resulted in higher photocarrier reduction rates: field-enhanced photodegradation. We report the result for polymer-dispersed pyrromethene mixed with dimethylbenzoquinone (electron acceptor) or triphenylamine (electron donor) and vacuum deposited samples. The photocarrier reduction is correlated with the appearance of dark spots, as confirmed by optical microscopy. For these samples, the photocarrier reduction is attributed to intrinsic degrading reaction of dye ions resulting from the optical excitation in the presence of strong electric fields.

Formation and expansion of dark spots in stratifying foam films

The stratification of thin liquid films formed from micellar solutions or latex suspensions can be explained by layer-by-layer destruction of a colloid crystal structure inside the film. The stepwise decrease of the film thickness is due to appearance and growth of dark spots (of less thickness) in the film. This phenomenon is analyzed in the present paper, and an explanation is proposed. The driving force for the stepwise thinning of the film is attributed to the gradient of the chemical potential of micelles at the film periphery. Therefore, the appearance and expansion of spots in the film are controlled by the micellar self-diffusion, rather than by normal instabilities. The spots are considered as condensed states of vacancies in the micellar structure inside the film, and the appearance of dark spots is interpreted as a phase transition. This explanation of the mechanism of stratification phenomenon is supported by the data for formation and expansion of spots.

Phages in eukaryotic cells.

Urine from a patient after kidney transplantation added to a human embryonic lung culture caused the appearance of dark spots shown to contain cells with phages resembling group A, as well as bodies resembling Chlamydiae.