Background: There is evidence from observational studies that skin microbiota is linked to skin cancers. Nevertheless, the causal association between skin microbiota and skin cancers is yet to be fully clarified.Methods: A bidirectional two-sample Mendelian randomization (MR) was performed to determine the causal relationship between skin microbiota and skin cancers. A total of 294 skin microbial taxa were identified from the first genome-wide association study across three skin microenvironments of two German population cohorts. Summary data of three skin cancers (malignant melanoma, squamous cell carcinoma, and basal cell carcinoma) were obtained from the FinnGen consortium. Moreover, sensitivity analysis examined horizontal pleiotropy and heterogeneity, and microenvironment-based meta-analysis confirmed the reliability of the results.Results: We identified 65 nominal causalities and 5 strong causal associations between skin microbiota and skin cancers. Among them, the class Bacilli revealed a bidirectional positive relationship with malignant melanoma. The class Betaproteobacteria and class Gammaproteobacteria demonstrated a causal association with an elevated risk of malignant melanoma and basal cell carcinoma, respectively. In the reverse MR analysis, malignant melanoma was associated with a lower abundance of phylum Bacteroidetes. There were no indications of significant heterogeneity in instrumental variables or evidence of horizontal pleiotropy.Conclusion: Our MR analysis indicated bidirectional causal associations between skin microbiota and skin cancers, and had the potential to offer novel perspectives on the mechanistic of microbiota-facilitated carcinogenesis.

Objectives: There is evidence from observational studies that human microbiota is linked to skin appendage Disorders (SADs). Nevertheless, the causal association between microbiota and SADs is yet to be fully clarified.Methods: A comprehensive two-sample Mendelian randomization (MR) was first performed to determine the causal effect of skin and gut microbiota on SADs. A total of 294 skin taxa and 211 gut taxa based on phylum, class, order, family, genus, and ASV level information were identified. Summary data of SADs and eight subtypes (acne vulgaris, hidradenitis suppurativa, alopecia areata, rogenic alopecia, rosacea, rhinophyma, seborrhoeic dermatitis, and pilonidal cyst) were obtained from the FinnGen consortium. We performed bidirectional MR to determine whether the skin and gut microbiota are causally associated with multiple SADs. Furthermore, sensitivity analysis was conducted to examine horizontal pleiotropy and heterogeneity.Results: A total of 65 and 161 causal relationships between genetic liability in the skin and gut microbiota with SADs were identified, respectively. Among these, we separately found 5 and 11 strong causal associations that passed Bonferroni correction in the skin and gut microbiota with SADs. Several skin bacteria, such as Staphylococcus, Streptococcus, and Propionibacterium, were considered associated with multiple SADs. As gut probiotics, Bifidobacteria and Lactobacilli were associated with a protective effect on SAD risk. There was no significant heterogeneity in instrumental variables or horizontal pleiotropy.Conclusions: Our MR analysis unveiled bidirectional causal relationships between SADs and the gut and skin microbiota, and had the potential to offer novel perspectives on the mechanistic of microbiota-facilitated dermatosis.

Background: Stroke is a major global cause of death and disability, with high body mass index (HBMI) as a key modifiable risk factor. Understanding HBMI‐attributable stroke burden is crucial for effective prevention. Methods and Results: Using Global Burden of Disease 2021 data, we analyzed disability‐adjusted life years and mortality from stroke and its subtypes (ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage) attributable to HBMI at global, regional, and national levels from 1990 to 2021. We conducted decomposition, frontier, inequality, and predictive analyses to assess epidemiological trends and future projections up to 2035. Despite country‐specific variations in disability‐adjusted life years and mortality, the global burden of stroke and its subtypes attributable to HBMI has increased from 1990 to 2021. Frontier analysis indicated that countries with higher sociodemographic index were expected to own lower age‐standardized rates for stroke and its subtypes attributable to HBMI. Decomposition analysis revealed that population growth and aging were the primary contributors to the rise. Significant cross‐country disparities remained, although inequality analysis showed a decline in SDI‐related differences over time. The projected annual rise in disability‐adjusted life years and mortality from 2021 to 2035 suggested ongoing significant challenges in stroke control and management in the coming decades. Conclusion: The global health challenge posed by the increasing burden of stroke and its subtypes attributable to HBMI remains significant, especially in low‐ and middle‐sociodemographic index regions. Targeted lifestyle modifications and policy interventions are crucial for reducing HBMI and mitigating stroke burden, warranting special attention from policymakers in high‐burden regions.

In this paper, a polarization filter based on photonic crystal fiber (PCF) with nanoscale gold film is proposed and analyzed theoretically. The cross-section of the structure is composed of four-layer air holes with a hexagonal lattice and two symmetrical air holes in the sub-internal layer are coated with gold film. We research that the PCF structure parameters affect the performances of the polarization filter through employing the finite element method. It is indicated by the numerical results that the resonance strength in y-polarization direction can reach a most value of 272.8 dB/cm at the communication wavelength of 1.55 μm. The extinction ratio can be better than 20 dB within a wavelength range from 1.45 μm to 1.75 μm when the length of the PCF is longer than 500μm. Therefore, such a length can make the communication filtering effect be realized using a shorter fiber. The calculated results can provide some references to the design of polarization micro-filter devices.