BACKGROUND: Androgenetic alopecia (AGA) is a prevalent form of hair loss that affects both men and women, severely impacting patients\' quality of life. Traditional treatments include oral medications, topical medications, and hair transplantation, but these methods have certain side effects and limitations. How to safely effectively and maximally promote hair growth has been a key issue in the treatment of AGA. In recent years, fractionated laser therapy, as a noninvasive method, has gradually gained attention due to its minimally invasive and highly effective nature.
OBJECTIVE: In this paper, we summarized the studies related to fractional laser treatment of AGA in the past 15 years, and discussed its therapeutic mechanism, clinical effect, future development direction, and advantages and disadvantages compared with traditional treatment methods in the treatment of AGA.
METHODS: An extensive literature search was conducted using PubMed, Google, Google Scholar, Embase, and Scopus. All available articles studying fractional laser treatment of AGA were compiled in March 2024. Titles and abstracts were then screened for relevance and thoroughly examined for patient clinical outcomes. Prospective clinical trials, retrospective chart reviews, case series, and individual case reports were included in the literature review.
CONCLUSIONS: Fractional laser treatment of AGA showed remarkable efficacy and high safety. Compared with traditional treatments, fractional laser has the advantages of minimally invasive, quick recovery, fewer side effects, and a wide range of population applicability, providing an effective treatment option for AGA patients. Further large-scale clinical studies will help optimize the laser parameters and treatment settings to improve the therapeutic effect.

To investigate the efficacy of Fractional Radiofrequency Microneedling (FRM) in treating corticosteroid-induced facial erythema.
A retrospective study was conducted involving eight patients diagnosed as corticosteroid-induced facial erythema. Each patient underwent a single session of FRM. Evaluative measures included Clinician\'s Erythema Assessment (CEA), Patient\'s Self-Assessment (PSA), assessment of telangiectasia severity, procedure-associated pain (10-point scale), patient satisfaction (3-point scale) and secondary outcomes.
The study found a 75% success rate and 100% effectiveness rate in alleviating erythema symptoms. CEA and PSA scores decreased by 67.7% and 78.1%, respectively. No cases of erythema rebound were recorded during the 3-month follow-up period.
FRM demonstrated effectiveness and safety in treating facial erythema, offering promising advancement in dermatologic therapeutics.

Protein generation has numerous applications in designing therapeutic antibodies and creating new drugs. Still, it is a demanding task due to the inherent complexities of protein structures and the limitations of current generative models. Proteins possess intricate geometry, and sampling their conformational space is challenging due to its high dimensionality. This paper introduces novel Markovian and non-Markovian generative diffusion models based on fractional stochastic differential equations and the Lévy distribution, allowing for a more effective exploration of the conformational space. The approach is applied to a dataset of 40,000 proteins and evaluated in terms of Fréchet distance, fidelity, and diversity, outperforming the state-of-the-art by 25.4%, 35.8%, and 11.8%, respectively.

OBJECTIVE: The aim of this study was to assess the safety and immunogenicity of a dose-sparing fractional intradermal (ID) booster strategy with the mRNA-1273 COVID-19 vaccine.
METHODS: COVID-19 naive adults aged 18-30 years were recruited from a previous study on primary vaccination regimens that compared 20 μg ID vaccinations with 100 μg intramuscular (IM) vaccinations with mRNA-1273 as the primary vaccination series. Participants previously immunized with ID regimens were randomly assigned (1:1) to receive a fractional ID booster dose (20 μg) or the standard-of-care intramuscular (IM) booster dose (50 μg) of the mRNA-1273 vaccine, 6 months after completing their primary series (ID-ID and ID-IM group, respectively). Participants that had received a full dose IM regimen as the primary series, received the IM standard-of-care booster dose (IM-IM group). In addition, COVID-19 naive individuals aged 18-40 years who had received an IM mRNA vaccine as the primary series were recruited from the general population to receive a fractional ID booster dose (IM-ID group). Immunogenicity was assessed using IgG anti-spike antibody responses and neutralizing capacity against SARS-CoV-2. Cellular immune responses were measured in a sub-group. Safety and tolerability were monitored.
RESULTS: In January 2022, 129 participants were included in the study. Fractional ID boosting was safe and well tolerated, with fewer systemic adverse events compared with IM boosting. At day 28 post-booster, anti-spike S1 IgG geometric mean concentrations were 9106 (95% CI, 7150-11 597) binding antibody units (BAU)/mL in the IM-IM group and 4357 (3003-6322) BAU/mL; 6629 (4913-8946) BAU/mL; and 5264 (4032-6873) BAU/mL in the ID-IM, ID-ID, and IM-ID groups, respectively.
CONCLUSIONS: Intradermal boosting provides robust immune responses and is a viable dose-sparing strategy for mRNA COVID-19 vaccines. The favourable side-effect profile supports its potential to reduce vaccine hesitancy. Fractional dosing strategies should be considered early in the clinical development of future mRNA vaccines to enhance vaccine availability and pandemic preparedness.

OBJECTIVE: The validation of mathematical models of tumour growth is frequently hampered by the lack of sufficient experimental data, resulting in qualitative rather than quantitative studies. Recent approaches to this problem have attempted to extract information about tumour growth by integrating multiscale experimental measurements, such as longitudinal cell counts and gene expression data. In the present study, we investigated the performance of several mathematical models of tumour growth, including classical logistic, fractional and novel multiscale models, in terms of quantifying in-vitro tumour growth in the presence and absence of therapy. We further examined the effect of genes associated with changes in chemosensitivity in cell death rates.
METHODS: The multiscale expansion of logistic growth models was performed by coupling gene expression profiles to the cell death rates. State-of-the-art Bayesian inference, likelihood maximisation and uncertainty quantification techniques allowed a thorough evaluation of model performance.
RESULTS: The results suggest that the classical single-cell population model (SCPM) was the best fit for the untreated and low-dose treatment conditions, while the multiscale model with a cell death rate symmetric with the expression profile of OCT4 (Sym-SCPM) yielded the best fit for the high-dose treatment data. Further identifiability analysis showed that the multiscale model was both structurally and practically identifiable under the condition of known OCT4 expression profiles.
CONCLUSIONS: Overall, the present study demonstrates that model performance can be improved by incorporating multiscale measurements of tumour growth when high-dose treatment is involved.

The appearance of skin scars is known as one of the main side effects of skin burns. Stromal vascular fraction (SVF), as a rich source of cell populations with tissue regeneration properties, plays an important role in the healing of skin lesions. Fractional CO2 lasers have occupied a special place in treating skin lesions, particularly skin scars, since their introduction. Our study aimed to compare the combination of SVF and fractional CO2 laser with fractional CO2 laser alone in the treatment of burn scars.
This double-blind clinical trial study was conducted on ten patients with burn scars that were treated three times with a fractional CO2 laser at site of burn lesions, and one of the two areas studied was randomly injected with SVF. Two months after completion of the procedure, patients\' scars were assessed using the Vancouver scar scale (VSS), biometric criteria, and physician and patient satisfaction ratings.
The results confirmed a significant improvement in VSS, cutometry, R7 criteria, complete density sonography, and skin density sonography in the fractional CO2 laser-treated group. The VSS criteria, epidermal thickness sonography, complete density sonography, and skin density sonography in the group treated with the combination of fractional CO2 laser and SVF also showed significant improvement. The VSS criteria and melanin index of Mexameter in the group treated with SVF in combination with fractional CO2 laser were significantly better than the group treated with fractional CO2 laser alone. Also, physician and patient satisfaction in the group treated with SVF injection in combination with fractional CO2 laser was significantly higher than the other group.
The results confirm the efficacy of SVF injection in combination with fractional CO2 laser in the treatment of burn scars and can be considered as a treatment option for better management of these lesions.
The study protocol was retrospectively registered at Iranian Registry of Clinical Trials with code: IRCT20210515051307N1, Registration date: 2021-11-14, URL: https://www.irct.ir/trial/56337 .

To examine the efficacy and safety of a new fractional, ablative erbium:glass fiber (Er:glass) laser (2910 nm) at improving clinical signs of photodamaged skin.
Thirty-seven healthy participants aged 38-75 years with photodamaged skin were enrolled into two treatment groups. Group A (n = 14) received up to four laser treatments with mild settings, and focal facial subunits were treated with deeper settings. Group B (n = 23) received a single treatment using deeper settings. Following treatment, pain scores and severity and duration of skin responses (erythema, edema, and pinpoint bleeding) were assessed. Primary outcome was the improvement in participant and investigator Global Aesthetic Improvement Scale (GAIS) at 3-month follow-up. Secondary outcomes were participant satisfaction with treatment and whether they would repeat treatment.
Thirty-five participants completed the study (n = 1 lost to follow up in each group). Both groups had similar mean participant and investigator GAIS scores of 3/5 corresponding to \"Improvement.\" All but two patients (both from Group A) reported improvement, satisfaction with treatment, and would repeat treatment. Posttreatment skin responses were mild-to-moderate, lasting up to 5 days. There was no scarring or dyspigmentation.
The 2910 nm Er:glass laser provided improvement in photoaging with high patient satisfaction.

To investigate the impact of ablative fractional carbon dioxide laser (AFCO2L) on patient-reported outcomes measures, subjective scar appearance, dermal architecture, and gene transcription in early burn scars.
Fifteen adult patients with a burn-related scar were recruited. Inclusion criteria were two non-contiguous scar areas of 1% total body surface area, similar baseline Vancouver scar scale (VSS) score and 3months since the time of injury. All participants acted as their own control. Scars were randomized to treatment or control. Treatment scars received three AFCO2L treatments at 6-week intervals. Outcome measures were recorded at baseline, 3, 6, and 12-months post-treatment. Measures included blinded VSS, Patient Observer Scar Assessment Scale (POSAS), Brisbane Burn Scar Impact Profile (BBSIP), blinded scar photo assessment, histological tissue analysis, and RNA sequencing analysis.
No significant difference was found in VSS, scar erythema, or pigmentation. Patient POSAS improved in scar thickness and texture following AFCO2L. All elements of BBSIP improved in control and laser groups. AFCO2L-treated scars were scored better than control scars by blinded raters. RNA sequencing illustrated that AFCO2L induced sustained changes in fibroblast gene expression.
AFCO2L treated scars had significantly altered scar thickness and texture 6 months post-laser and were rated better than controls on blinded photo analysis after 3 treatments. RNASeq results suggest laser treatment alters the transcriptome of treated fibroblasts for at least 3 months after treatment. Expansion of this research to study in more depth fibroblast changes in response to laser, as well as assessing the impact on daily activity and quality of life, will be beneficial.

UNASSIGNED: Acne is very common among adolescents, which may sometimes persist into adulthood, and acne scars continue to have a profoundly negative impact on quality of life. Of all the various modalities available, fractional lasers have shown effective results.
UNASSIGNED: The aim of this study was to assess the efficacy and safety of fractional carbon dioxide (CO2) laser resurfacing in atrophic facial acne scars.
UNASSIGNED: The study included 104 subjects aged ≥18 years with atrophic acne scars on face of more than 6 months of duration recruited over a period of 1 year. All the patients were treated with fractional CO2 laser (600 W power and wavelength 10,600 nm). Four sessions of fractional CO2 laser resurfacing were done at 6-week intervals in each patient. We compared the improvement rate of scars after every session at 6-week interval, 2 weeks after the last session, and finally 6 months after the last laser session.
UNASSIGNED: The difference between the mean baseline score (3.43) and mean final score (1.83) using Goodman and Baron\'s qualitative scar scale was found to be statistically significant (P = 0.001). Mean improvement increased from first treatment session to the end of the treatment course from 0.56 to 1.62 indicating the role of the number of sessions in the overall improvement of acne scars. With regard to overall satisfaction, maximum number of patients were either very satisfied (55.8%) or satisfied (25%) as compared to those who were only slightly satisfied (11.5%) or completely unsatisfied (7.7%).
UNASSIGNED: Fractional ablative laser gives excellent results in the management of acne scars and has emerged as an appealing non-invasive option for this indication. Being a safe and effective option for atrophic acne scar treatment, it can be recommended wherever available.

BACKGROUND: Conventional fractional lasers (FLs) are well-established treatments for acne scars with some inevitable adverse events. Fractional picosecond laser (FPL) is increasingly used for acne scars.
OBJECTIVE: To compare the efficacy and safety of FPL with non-picosecond FLs for acne scars.
METHODS: PubMed, Embase, Ovid, Cochrane Library, and Web of Science databases were searched. We also searched ClinicalTrials, WHO ICTRP, and ISRCTN websites. A meta-analysis was conducted to assess the clinical improvement and adverse events after FPL compared with other FLs.
RESULTS: Overall, seven eligible studies were included. Three physician evaluation systems showed no difference between FPL and other FLs in clinical improvement of atrophic acne scars (MD = 0.64, 95% CI:-9.67 to 10.94; MD = -0.14, 95% CI:-0.71 to 0.43; RR = 0.81, 95% CI:0.32 to 2.01). Patient-assessed effectiveness was also not significantly different between FPL and other FLs (RR = 1.00, 95% CI:0.69 to 1.46). Although temporary pinpoint bleeding was more common after FPL (RR = 30.33, 95% CI:6.14 to 149.8), the incidence of post-inflammatory hyperpigmentation (PIH) and pain level were lower for FPL (RR = 0.16, 95% CI:0.06 to 0.45; MD = -1.99, 95% CI:-3.36 to -0.62). Additionally, edema severity after treatment did not differ between the two groups (MD = -0.35, 95% CI:-0.72 to 0.02). As for the duration of erythema, no difference between FPL and nonablative FL groups (MD = -1.88, 95% CI:-6.28 to 2.51).
CONCLUSIONS: FPL seems similar to other FLs regarding clinical improvement of atrophic acne scars. With lower PIH risk and pain scores, FPL is more suitable for acne scar patients prone to PIH or sensitive to pain.