Search

In order to promote the development of hair transplantation, particularly the establishment of standards, the Hair Transplantation Expert Group of Plastic and Aesthetic National Medical Quality Control Center invited experts in the field of hair transplantation across China and formed a draft of the Expert Consensus on Standard Terminology for Hair Transplantation based on the collation of relevant literature and monographs. By combining Delphi methodology and consensus meetings, the expert group conducted several rounds of consultations on issues such as follicular unit anatomy, harvesting, dissection, and implantation, ultimately presenting 54 terminologies. This consensus considers the original Chinese and English meanings as well as the professional characteristics of terms used in hair transplantation, highlights the unique features and advantages of hair transplantation, and preserves its essence while promoting innovation, with the hope of providing valuable reference for clinical researchers engaged in hair transplantation both domestically and internationally, and better facilitating the standardization and advancement of the field.

Thin slab continuous casting and rolling process is an important way to produce hot-rolled strips. Recently, the process has been widely used to produce Nb/V/Ti/B bearing microalloyed steel. However, during the continuous casting of the thin slabs of the microalloyed steel, there are frequent cracks on the corners of the slabs, which would cause quality defects, such as scars and cracks at the edges of the hot-rolled coils. These defects are a common technical issue in the steel industry. In this paper, the characteristics of the microstructure and carbonitride precipitation of the thin slab corner of QStE380TM low carbon niobium–titanium bearing microalloyed steel, as well as the reduction of area of the steel under different cooling and tensile rates, were detected. Moreover, the evolutions of the temperature of the solidified shell in different structure molds and secondary cooling processes, as well as the stress of the thin slab surface during liquid core reduction, were numerically simulated. The results show that there is a significant third brittle temperature zone during continuous casting of microalloyed steel thin slabs, and the greater the deformation rate of the thin slab, the more significant the third brittle temperature zone is. Under the conventional thin slab continuous casting process, the cooling rate of the thin slab corners in the upper part of the mold and the secondary cooling zone from the mold exit to the liquid core reduction segment is lower than 5 °C·s−1, which is the key factor to lead a chain of niobium–titanium carbonitrides precipitate at the grain boundaries of the corners. As a result, the plasticity of the thin slab corners is greatly reduced. During the process of liquid core reduction, the low plasticity corners of the thin slab crack because of large deformation and stress. Applying the Gaussian concave curved surface mold, which the narrow face copper plates could efficiently compensate the shell shrinkage, the narrow face-foot roll zone hard cooling process can increase the cooling rates of the thin slab corners over 10 and 20 °C·s−1 in the mold and the narrow face-foot roller cooling zone, respectively. As a result, the carbonitrides precipitate in the thin slab corners disperses, and the stress of the thin slab corners reduces since the new mold promotes the metal flow of slab narrow surface broadsiding during the liquid core reduction. Finally, the cracking rate of the thin slab corners during the microalloyed steel thin slab casting has been reduced significantly.

Background: Depletion or permanent quiescence of the hair follicle stem cell (HFSC) pool underlies pathogenesis in androgenetic alopecia (AGA). Reactivation of quiescent HFSCs is considered an efficient treatment strategy for hair loss. The retinoic acid (RA) is critical to ensure stem cell homeostasis and function. However, little is known about whether RA regulates HFSC homeostasis. We aimed to investigate the impact of RA on HFSC homeostasis and the underlying mechanisms, in order to provide new potential targets for medical therapies of AGA. Methods: Microdissected hair follicles from the occipital and frontal scalp in AGA were obtained for RNA sequencing analysis and test. The C57BL/6 mice model in telogen was established to investigate the effect of exogenous RA. Miniaturized hair follicles from frontal scalp were incubated with or without RA in hair follicle organ culture to test the effects on hair shaft elongation, hair cycling and HFSC activities. A strategy to characterize the effect of RA on HFSC in primary culture was developed to identify novel mechanisms that control HFSC activation. A clinical study was performed to test the efficacy of RA treatment in AGA patients. Results: RA signalling was inhibited in the course of AGA pathogenesis along with HFSC dysfunction. Hair regeneration was retarded in AGA miniaturized hair follicles with RA deficiency, but they tended to recover after treatment with RA. In addition, RA treatment during the telogen phase facilitated HFSC anagen entry and accelerated hair growth. Mechanistically, RA promoted hair growth by stimulating stem cells via Wnt/β‐catenin signalling and accelerating the transition from a dormant to an activated state. Furthermore, a clinical study suggested that RA has obvious advantages in the early intervention of AGA by reactivating HFSCs. Conclusions: Our study provides insights into the reactivation of HFSCs in AGA and provides potential targets for medical therapies. [ABSTRACT FROM AUTHOR]

High-speed continuous casting is the theme for developing a new generation of high-efficiency continuous casting technology as well as a high-efficiency and green steelmaking production line. Presently, the actual casting speed for slabs in China is no more than 1.8 m·min−1, and it is in the range of 1.2–1.4 m·min−1 for continuous casting of peritectic steel. With the increase in the casting speed, the negative factors affecting the solidification in continuous casting mold become more evident, and the lubrication between mold copper plate and solidifying shell deteriorates. The friction force increases due to the increase of heat flux and decrease of mold flux consumption. Hence, the thickness of solidifying shell reduces and becomes nonuniform, decreasing its ability to resist all types of stress and strain during casting. Thus, the occurrence of breakout and cracks with high frequency greatly influences production. The technical issue of high-speed casting and the key to making it a reality should be resolved to ensure homogeneous growth. In this paper, the behavior of heat transfer and solidification in slab mold with high-speed casting for peritectic steel was analyzed. The effect of casting speed on the interfacial heat transfer resistance and the distribution of temperature and stress for solidifying shells in mold were investigated. It was found that the interfacial heat resistance increased evidently as the casting speed was greater than 1.6 m·min−1. The thickness of solidified shell at the exit of the mold was reduced by approximately 10%, as the casting speed increased from 1.4 m·min−1 to 1.6 m·min−1 and 1.8 m·min−1, making it more dangerous for breakout. The relative technologies such as the shape, flux, oscillation, and surface fluctuation for mold with homogenous solidification were presented and discussed. The optimization of mold inner cavity fitting for the growth of solidifying shell should be considered first for the uniformity control of peritectic steel solidification in a high-speed continuous casting mold. It is critical to design mold flux that adjusts to the solidification characteristics of peritectic steel. Moreover, the control of strand bulging is the key to stabilizing the mold surface.