Effect of De-epithelialization on Graft Survival Rate After Follicular Unit Extraction.

BACKGROUND: To achieve a natural postoperative appearance, hair grafts are often de-epithelialized from the epidermis during follicular unit extraction (FUE). However, the effect of de-epithelialization on the survival rate of transplanted hair follicles (HFs) has not been investigated. OBJECTIVE: To investigate the effect of de-epithelialization on the survival rate of transplanted HFs. METHODS: A total of 64 male patients with androgenetic alopecia were included in this study. They were randomly divided into de-epithelialization and control groups. Organ culture was performed to assess the elongation of hair shaft and the percentage of anagen HFs in both groups. Patients were followed up postoperatively to evaluate complications, postoperative shedding, survival rates, and satisfaction. RESULTS: No significant difference in hair shaft elongation and percentage of anagen HFs was observed between both groups. The immediate postoperative satisfaction in the control group was much lower than that in the de-epithelialization group (71.25% and 100%, respectively). No significant differences in shedding rate, graft survival rate, and complications were noticed between both groups. CONCLUSION: Follicular de-epithelialization does not affect the survival rate of graft in FUE. Based on these data, de-epithelialization may improve immediate postoperative appearance and lead to a more pleasing cosmetic outcome.

Clinical experience on follicular unit extraction megasession for severe androgenetic alopecia.

BACKGROUND: Severe androgenetic alopecia has significant impact on patients' self-image and emotional health. As the most advanced way to achieve the growth of a full head of hair in shortest period of time, the megasession hair transplant procedure is a promising treatment for severe androgenetic alopecia. AIMS: To introduce the procedure and technical details of follicular unit extraction megasession and to evaluate the surgery outcome. METHOD: A total of 273 male patients undergoing follicular unit extraction (FUE) megasession between 2016 and 2018 were included in our study. The extraction was performed using 1.0 mm punch. The BASP classification degree of patient hair loss, the number of extracted hair, surgery consuming time, and graft survival rate were recorded. We finally evaluated patients' satisfaction with surgery outcomes. RESULTS: Ages of patients ranged from 28 to 53 years, with a mean of 42 years (SD, 8.42). All of them were at C3 and U1 degree of BA type hair loss according to the BASP classification. The number of follicular units transplanted was between 3000 and 6000, with surgery duration range from 6 hours to 12 hours and graft survival rate varies from 93.5% to 96.6%. A total of 81% of them were satisfied with the outcomes, 19% of them had a second procedure performed to provide further hair density. None of them had infection after the surgery. CONCLUSION: Compared with multi-stage hair transplantation, FUE megasession has the advantages of reducing operation frequency and overall surgery duration. Thus, FUE megasession is an appealing treatment option for severe AGA patients, who expect to a more desirable natural and esthetically pleasing result in a one-stage operation.

[Improving accumulation-mode fraction based on spectral aerosol optical depth in Beijing].

In the present study, the authors put forward a parameterization method of correcting fine-mode Angstrom index with aerosol optical depth and volume distribution of aerosol derived from AERONET in Beijing over 2011. The parameterization method is coupled with aerosol optical depth spectral deconvolution algorithm to improve the accuracy of accumulation-mode fraction. The errors of estimated AMF are derived from underestimate of fine-mode Angstrom index errors. We calculate and simulate the extreme values of fine-mode Angstrom index, getting constraint conditions, and then establish the extreme values correction method. Results from sensitivity test suggest that extreme values of fine-mode Angstrom index are constrained in the reasonable range. Finemode Angstrom index and AMF are sensitive to normalized volume distribution of aerosol, ranging from 0.662 to 2.849 and from 0.08 to 0.84 due to different distribution. Mean deviation of accumulation-mode fraction is reduced from 0.072 to 0.044, and the difference is 38.89%, especially in winter and summer. Improving computational accuracy of accumulation-mode fraction can enhance that of anthropogenic aerosol optical thickness, and it has important significance of anthropogenic aerosol direct radiation force estimation and environmental quality assessment.

[Retrieval of dust fraction of atmospheric aerosols based on spectra characteristics of refractive indices obtained from remote sensing measurements].

Mineral dust is an important chemical component of aerosol, which has a significant impact on the climate and environmental changes. The spectral behavior of aerosol refractive indices at four wavelengths from 440 to 1 020 nm was analyzed based on one year observation obtained from Beijing AERONET site. The real parts of refractive index (n) in each band did not differ greatly, however the imaginary parts (k) showed a significant difference due to the absorption of mineral dust in aerosol. From 440 to 670 nm k decreased rapidly, while from 670 to 1 020 nm featured a lower, constant value. Accordingly, k(440 nm) could be considered separately with other three bands. Hence, we added mineral dust into the currently used three-component aerosol chemical model to form a new four-component model (i. e. BC, AS, dust and water) which is more suitable to represent the aerosol chemical composition. Then we presented a method to retrieve dust content in aerosols using this four-component model and refractive indices obtained from the sunphotometer measurements. Finally the dust content in aerosol was investigated under different weather conditions, i. e. clear, haze and dust in Beijing. The results showed that volume fractions of the dust component were 88%, 37% and 48% for clear, hazy and dusty day respectively, which was consistent with the coarse mode proportion in aerosols calculated from aerosol size distributions.