M2 Macrophage Polarization and Tissue Remodeling in Autologous Fat Grafting for Diabetic Skin Defects.

Autologous adipose tissue was recognized as a promising therapeutic option for soft tissue defects owing to its regenerative potential and ability to facilitate tissue reconstruction. However, the mechanisms by which autologous fat grafting (AFG) promotes healing remain unclear, hindering its potential applications. This study aimed to investigate the distribution and phenotypic transition of infiltrating macrophages in transplanted adipose tissue, as well as their correlation with diabetic skin defect remodeling. Streptozotocin-induced diabetic rats with full-thickness dorsal skin defects were included in this study. The transplanted adipose tissue at the skin defects was collected and analyzed using flow cytometry to determine macrophage proportion and phenotype. The healing of skin defects was evaluated, and treatment was continued until day 14 as the designated endpoint of healing, followed by histopathologic examinations. Immunostaining with CD31 and lymphatic vessel endothelial receptor-1 was performed on wound tissues to analyze angiogenesis and lymphangiogenesis, respectively. Western blot and quantitative polymerase chain reaction analyses were used to assess the expression of the representative genes involved in the healing process. The results showed early polarization of M2 macrophages in the transplanted adipose tissue, concomitant with the upregulation of growth factors and downregulation of inflammatory factors. In vivo experiments revealed that AFG significantly promoted macrophage infiltration and M2 transformation in diabetic skin defects compared to the control groups, thereby promoting tissue extracellular matrix remodeling and lymphatic and vascular regeneration. However, the beneficial effects of AFG were inhibited by macrophage depletion. This study further demonstrated the potential of AFG for treating diabetic skin defects.

Double Chin Concerns after En Bloc Mandibular U-Shaped Osteotomy: Submental-Cervical Soft Tissue Changes and Anterior Belly of Digastric Muscle Assessment.

OBJECTIVE: To assess submental-cervical soft tissue changes after en bloc mandibular U-shaped osteotomy and examine alterations in the anterior belly of digastric muscle (ABDM). METHODS: A retrospective study analyzed 20 patients who underwent en bloc mandibular U-shaped osteotomy from 2018 to 2023. Preoperative (Tp) and long-term follow-up (Tf) CT data were collected for analysis, measuring mandibular volume, soft tissue thickness at menton (Mes) and cervicale (C), and ABDM parameters (length, cross-sectional area (CSA), volume, distance from centroid point to the mandibular margin). Correlation analyses were performed to investigate the connection between soft tissue thickness changes, ABDM changes, and mandibular osteotomy volume. RESULTS: Long-term follow-up revealed a significant increase in soft tissue thickness at the Mes and C points after U-shaped mandibular osteotomy, especially at the C point. The adaptive length of ABDM decreased, CSA increased, and volume decreased, but the ABDM centroid point shifted downward relative to the mandibular margin, indicating drooping protrusion. The increment of soft tissue thickness was moderately positively correlated with the amount of osteotomy, and the decrement of ABDM length and volume were slightly positively correlated with the amount of osteotomy. CONCLUSION: The degree of soft tissue relaxation after U-shaped osteotomy is related to the extent of osteotomy. Notably, the protrusion of ABDM relative to the mandibular margin affects submental-cervical contour aesthetics. Prior to U-shaped osteotomy, it is crucial to assess the soft tissue condition of the patient's lower face, and the individualized design of the osteotomy volume should be carried out cautiously and safely. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Redefining Mandibular Sub-units: The "ABC" Classification and Surgical Strategies for Lower Face Contouring.

BACKGROUND: In east Asia, lower face contouring surgeries including reduction mandibuloplasty and genioplasty are the most popular aesthetic craniofacial surgeries. Conventional selection of surgical strategies mainly relied on the visual judgment of the mandibular angle, without overall assessment of the mandibular sub-units. Furthermore, only a few studies offered quantitative assessment of the mandibular shape. METHODS: From 2010 to 2021, 1241 patients diagnosed with square faces and received customized lower face contouring surgeries by the senior author were reviewed and analyzed to propose an "ABC" classification system for facilitating surgical planning. RESULTS: Among them, 998 (80.42%) received bilateral mandible reshaping, 155 (12.49%) underwent bilateral mandible reshaping combined with genioplasty, and 88 (7.09%) received asymmetric mandible reshaping. A modified classification system composed of three critical parameters (height, morphology/thickness, divergence) in three aesthetic zones (mandibular angle, mandibular body, chin) was proposed based on quantitative summarization of the CT database and the senior author's 12-year experience. The way to facilitate surgical planning with this classification was demonstrated. CONCLUSIONS: This modified classification system ushered a decision-making process that prioritized several critical measurements and proposed an operative planning form. Meanwhile, it can also be cooperated into the three-dimensional virtual surgical plan. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

Astaxanthin Promotes the Survival of Adipose-Derived Stem Cells by Alleviating Oxidative Stress via Activating the Nrf2 Signaling Pathway.

The survival of free fat grafts is dependent primarily on adipose-derived stem cells (ADSCs); however, ADSCs are susceptible to oxidative stress in the recipient area. Astaxanthin (Axt) is a natural xanthophyll carotenoid with potent antioxidant properties and numerous clinical applications. To date, the therapeutic potential of Axt in fat grafting has not been explored. The purpose of this study is to investigate the effects of Axt on oxidatively stressed ADSCs. An oxidative model of ADSCs was developed to simulate the host's microenvironment. Oxidative insult decreased the protein levels of Cyclin D1, type I collagen alpha 1 (COL1A1), and type II collagen alpha 1 (COL2A1), while increasing the expression of cleaved Caspase 3 and secretion of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in ADSCs. Axt pre-treatment significantly reduced oxidative stress, increased the synthesis of an adipose extracellular matrix, alleviated inflammation, and restored the impaired adipogenic potential in the present model. Furthermore, Axt immensely activated the NF-E2-related factor 2 (Nrf2) pathway, and ML385, an inhibitor of Nrf2, could negate Axt's protective effects. Additionally, Axt alleviated apoptosis by inhibiting bcl-2-associated X protein (BAX)/Caspase 3 signaling and improving the mitochondrial membrane potential (MMP), which could also be abolished by ML385. Our results suggest that Axt may exert its cytoprotective effect on ADSCs through the Nrf2 signaling pathway and could be therapeutic in fat grafting.

A Simple Dressing Fixation Method Following Harvest of the Ear Cartilage Graft.

ABSTRACT: Auricular cartilage is a common autologous graft material for rhinoplasty. Even though surgical techniques for the harvest of cartilage graft are well established, the management of the postoperative dressing fixation is still limited. Therefore, the authors propose a simple dressing fixation method in which gauze strips instead of gauze block or wet cotton, the suture of tie-over dressing fixed just through the cartilage rather than the full thickness of the auricle, a vaseline gauze interposed between the stitch knot and the skin and no additional pressure dressings postauricularly. No case of hematoma, infection and skin necrosis of the donor site was observed. This simple and reproducible technique provides perfect and homogeneous adhesion of the dressing all over the conchal cartilage while decreasing the risk of postoperative hematoma and discomfort.

A Modified Procedure for Single-eyelid Asian Females with Lacrimal Gland Prolapse: Lacrimal Gland Reposition combined with Fat Transposition in Double-eyelid Operation.

BACKGROUND: The awareness and treatment of lacrimal gland prolapse (LGP) have been primarily improved with a further understanding of lateral eyelid bulging over the decades. However, for Asian single-eyelid females with LGP, a tailor-made procedure applicable to their comparatively young puffy eyes is needed. METHODS: This is a retrospective study. From Jan. 2009 to Jan. 2019, two hundred and three Asian single-eyelid females with LGP, who met the inclusion criteria, underwent double-eyelid surgeries and adjunctive lacrimal gland repositions with preaponeurotic fat transposition. Pertinent demographics, complications, pre-and post-operative photography were collected. RESULTS: A total of 167 patients completed the 4-24 months' follow-up (average: 16.3 months). One hundred and thirty-two cases (79.0%) were diagnosed as LGP preoperatively, and the rest (35/167, 21.0%) were diagnosed intraoperatively. All patients (average: 28.4 years old) received modified blepharoplasty. Postoperative symptoms involving local mild pain (2.9%, 5/167), upper eyelid tightness (3.6%, 6/167), and moderate epiphora (9.0%, 15/167) were all recovered spontaneously within one month. Prolapse recurrence and severe complications such as dry eye syndrome were not observed. CONCLUSIONS: We proposed a modified procedure to enhance the diagnosis and treatment of LGP during Asian blepharoplasty. The lacrimal gland suspension and fat transposition assured the cosmetic outcome for selected young, puffy Asian eyes. The supratarsal creases were satisfactory, and the complication rate was low. Furthermore, the rearrangement of preaponeurotic fat smoothed the contour transition and preserved the orbital volume. Therefore, this is a safe and effective technique worth recommending.

Comparison of Bilateral Mandibular Angle Ostectomy Between East Asian Males and Females: A Study Based on Three-Dimensional Computed Tomography Reconstruction.

BACKGROUND: Mandibular angle ostectomy is a common plastic surgery for facial contouring in East Asians. However, rarely we could find reports on differences between East Asian males and females undergoing this surgery. OBJECTIVE: To describe the differences between East Asian males and females before and after mandibular angle ostectomy. METHODS: A total of 22 Asian males and 52 Asian females who underwent mandibular angle ostectomy from April 2015 to November 2018 were enrolled. Three-dimensional computed tomography was used to evaluate the preoperative and postoperative data of the mandible. Thirteen clinical data were measured on reconstructed mandibular models. The differences in data between males and females were analyzed to identify the causes of the differences before and after surgery. The follow-up was 6-12 months, and patient satisfaction was also evaluated. RESULTS: The ostectomy volume was positively correlated with the distance from the intersection of the occlusal plane and the anterior margin of the mandibular ramus to gonion (MR-Go; female, p < 0.01; male, p = 0.02). There was a positive correlation between the ostectomy volume and the postoperative drainage fluid (The drainage fluid is mainly blood) volume after surgery in females (p < 0.05), while there is no significant correlation between these two data in males (p = 0.19). Patients with a long distance from the second molar to the lower edge of the mandibular body (SM-MB) tended to have a higher risk of postoperative bleeding (female, r = 0.56, p < 0.01; male, r = 0.73, p = 0.01). CONCLUSION: Because of the difference in the anatomical size of the mandible and different aesthetic requirements for facial contouring between males and females, surgeons encounter different intraoperative conditions resulting in difficulties during surgery. Understanding differences in mandibular angles predicts differences in ostectomy volume and postoperative bleeding risk, thus aiding surgeons and leading to better operative outcomes. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

The Effect of Thymosin beta4 on the Survival of Autologous Fat Grafting: A Preliminary Study.

BACKGROUND: Autologous fat grafting is a common procedure to improve tissue deficiencies. However, the survival rate of fat grafting is unpredictable. Thymosin beta 4 (Tß4), a multifunctional peptide containing 43 amino acids, is effective in angiogenesis, inhibiting apoptosis and inflammation. OBJECTIVES: The authors initially investigated the potential effect of Tß4 in fat grafting. METHODS: Adipose tissue premixed exogenous Tß4 were transplanted into rabbit ears. Rabbits were randomly assigned to 3 groups: group A, 5 µg/mL Tß4; group B, 10 µg/mL Tß4; and group C, phosphate-buffered saline buffer as a blank control. The fat grafts were subjected to magnetic resonance imaging at 2, 4, and 12 weeks in vivo. Each harvested graft was analyzed at 3 time points after transplantation. RESULTS: The fat grafts in the Tß4-treated groups showed better volume and weight retention, greater adipose tissue integrity, adipocyte viability, and angiogenesis. The results of dynamic contrast-enhanced magnetic resonance imaging also showed that the experimental groups increased microcirculation perfusion of the grafts. CONCLUSIONS: The study proved that Tß4 could improve adipose tissue survival and neovascularization. It may be useful for fat grafting as a potential protective reagent.

Efficacy of Botulinum Toxin Type A in Improving Scar Quality and Wound Healing: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Botulinum toxin type A-induced "chemoimmobilization" has long been utilized for improved scar quality and wound healing; however, current evidence is limited to small studies, and evidence-based information is inadequate to make well-informed decisions. OBJECTIVES: The purpose of this study was to evaluate the efficacy of botulinum toxin type A (BTA) to improve scars and wound healing. METHODS: The authors searched databases, including Pubmed, Embase, and Cochrane Library, to identify randomized clinical trials (RCTs) that compared outcomes of surgical scars and wounds treated with BTA vs those treated with blank or placebo controls. The Visual Analog Scale, Vancouver Scar Score, scar width, and reported patient satisfaction were utilized in evaluating outcomes. Adverse events were also recorded. RESULTS: Eleven RCTs involved a total of 486 cases (374 patients). Quantitative synthesis suggested that compared with the control group, patients in the BTA treatment group had significantly higher Visual Analog Scale scores (mean difference [MD] = 1.30, 95% confidence interval [CI]: 1.05 to 1.55), lower Vancouver Scar Scores (MD = -1.62, 95% CI: -2.49 to -0.75, P = 0.0003), and thinner scars (MD = -0.15, 95% CI: -0.20 to -0.11, P < 0.00001). Patient satisfaction was higher in the BTA group than in the control group (risk ratio: 1.25, 95% CI: 1.06 to 1.49, P = 0.01). Trivial adverse events were reported. CONCLUSIONS: This meta-analysis of RCTs provides reliable evidence that BTA injection is superior to placebo or blank control group in improving scar quality and wound healing in the face and neck for Asians, and negative outcomes for BTA treatment in these patients include only trivial adverse events. However, inadequate evidence supports utilization of BTA in Caucasians for primary surgical scars or for scars in locations other than the face and neck. Further studies on the standardized injection regimen and technique of BTA are warranted for clinical practice.

The Anatomy and Clinical Application of Preorbital Septum Fiber.

BACKGROUND: In patients with mild superior sulcus deformity, pseudoptosis, or multiple eyelid folds, several bulky fibers can be found anterior to the orbital septum. These fibers, called preorbital septum fibers, may constrict protrusion of the fat pad and movement of the levator palpebrae muscle. OBJECTIVES: In this study, the authors illustrated the anatomy of these fibers and described the double-eyelid procedure to correct pseudoptosis, mild superior sulcus deformity, and multiple eyelid folds, which may be caused by these fibers. METHODS: The bulky preorbital septum fibers were dissected and severed during upper blepharoplasty to release the orbital septum fat pad and levator palpebrae muscle. This procedure was performed between January 2016 and January 2018 in 56 patients with distinct preorbital septum fibers. RESULTS: Of the 56 patients, 38 displayed mild to moderate upper eyelid depression and multiple eyelids, and 18 displayed pseudoptosis. Bulky fibers that existed in the superficial layer of the orbital septum were all dissected and removed. After 6 months' recovery, the superior sulcus deformity improved in all patients. No recurrence of multiple eyelids was observed. Patients with pseudoptosis showed a notable release of their upper eyelids. CONCLUSIONS: This is the first time to our knowledge that the preorbital septum fibers are described as a distinct anatomical structure. They are clinically important in upper eyelid anatomy and the improvement of sunken upper eyelids or pseudoptosis. The combination of blepharoplasty with release of these fibers is easy to perform and promote.

Single-Stage Mandibular Curved Ostectomy on Affected Side Combined with Bilateral Outer Cortex Grinding for Correction of Facial Asymmetry: Indications and Outcomes.

BACKGROUND: Facial asymmetry combined with a prominent mandibular angle is common in the population. Its treatment involves two or three stages of surgeries. Generally, orthognathic surgery is a top priority. However, some patients with no severe occlusion disorders focus on the appearance and could not accept complex therapeutic procedures. This study evaluated the surgical effect of en bloc mandibular angle-body-chin curved ostectomy (MABCCO) combined with traditional mandibular angle curved ostectomy (MACO) and bilateral outer cortex grinding (OCG) to correct facial asymmetry and a prominent mandibular angle. METHODS: From September 2013 to November 2017, a total of 40 patients with facial asymmetry and prominent mandibular angle were chosen for this study. The authors performed single-stage surgery of en bloc MABCCO combined with traditional MACO and bilateral outer cortex grinding to correct facial asymmetry. Patient satisfaction was investigated by questionnaires at 6 months postoperation. The effectiveness was then evaluated through cephalometric radiographs, three-dimensional computed tomography, and preoperative and postoperative standard facial photographs. RESULTS: The postoperative results of all 40 cases showed that facial asymmetry was effectively corrected without serious complications, and the square face was also significantly improved with a harmonious mandibular contour. There was a statistical difference between the patient's preoperative and postoperative satisfaction scores (p < 0.05). The objective esthetic outcomes evaluated by both surgeons and patients were quite satisfactory. CONCLUSION: Single-stage surgery of en bloc MABCCO combined with traditional MACO and bilateral OCG was an adaptable option for correction of facial asymmetry and prominent mandibular angle with slight occlusion disorders, which can both largely shorten treatment time and shape a harmonious face. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Identification of the Optimal Recipient Layer for Transplanted Fat: A Prospective Study on Breast Lipoaugmentation.

BACKGROUND: Fat grafting has become a popular procedure in aesthetic and reconstructive surgeries due to its safety, minimal invasiveness, and favorable visual outcomes, although the volume retention rate is unpredictable. OBJECTIVES: A prospective clinical study on lipoaugmentation of the breast was conducted to compare fat retention rates in the pectoralis muscle and the periglandular area. METHODS: This prospective study included 20 breasts from 11 patients who underwent primary lipoaugmentation. Volume retention rate and percentage augmentation among different recipient layers, as well as complications and patient satisfaction, were evaluated. Magnetic resonance imaging was performed preoperatively and at 1 day and 3 months postoperatively. Complications were recorded, and patient satisfaction was appraised through the use of the Breast-Q questionnaire. RESULTS: Breasts were injected with 207 ± 29 mL of fat, achieving overall volume retention rates of 56.63% ± 16.40%. The overall augmentation was 21.53% ± 10.27%. Volume retention rate was significantly higher (59.00% ± 13.84%) in the periglandular area than in the pectoralis muscle (47.21% ± 22.41%) (P = 0.04). Augmentation was significantly higher (32.13% ± 12.96%) in the periglandular area than in the pectoralis muscle (4.95% ± 4.23%) (P = 0.00). Pain and numbness were the only reported complications. The Breast-Q score increased significantly for the measures "satisfaction with breasts," "psychosocial well-being," and "sexual well-being." CONCLUSIONS: Fat transfer is a safe and acceptable method for aesthetic and reconstructive breast surgery. The periglandular area was a better recipient site than muscle for transferred fat.

Iron Oxide Nanoparticles-Based Vaccine Delivery for Cancer Treatment.

Modern therapeutic cancer vaccines need simple and effective formulations to enhance both humoral and cellular immune responses. Nanoparticles have obtained more and more attention in the development of vaccine delivery platforms. Moreover, nanoparticles-based vaccine delivery platform has high potential for improving the immunogenicity of vaccine. The Food and Drug Administration (FDA) has approved many types of iron oxide nanoparticles for clinical use, such as treating iron deficiency, contrast agents for magnetic resonance imaging (MRI) and drug delivery platforms. In this study, we explored a novel combined use of iron oxide nanoparticles (superparamagnetic Fe3O4 nanoparticles) as a vaccine delivery platform and immune potentiator, and investigated how this formulation affected cytokine expression in macrophages and dendritic cells (DCs) in vitro and tumor growth in vivo. Comparing with soluble OVA alone and iron oxide nanoparticles alone, we found significant differences in immune responses and tumor inhibition induced by OVA formulated with iron oxide nanoparticles. Our iron oxide nanoparticles greatly promoted the activation of immune cells and cytokine production, inducing potent humoral and cellular immune responses. These results suggest that this nanoparticle-based delivery system has strong potential to be utilized as a general platform for cancer vaccines.

Advances in redox-responsive drug delivery systems of tumor microenvironment.

With the improvement of nanotechnology and nanomaterials, redox-responsive delivery systems have been studied extensively in some critical areas, especially in the field of biomedicine. The system constructed by redox-responsive delivery can be much stable when in circulation. In addition, redox-responsive vectors can respond to the high intracellular level of glutathione and release the loaded cargoes rapidly, only if they reach the site of tumor tissue or targeted cells. Moreover, redox-responsive delivery systems are often applied to significantly improve drug concentrations in targeted cells, increase the therapeutic efficiency and reduce side effects or toxicity of primary drugs. In this review, we focused on the structures and types of current redox-responsive delivery systems and provided a comprehensive overview of relevant researches, in which the disulfide bond containing delivery systems are of the utmost discussion.

Six-Position, Frontal View Photography in Blepharoplasty: A Simple Method.

BACKGROUND: Photography plays a pivotal role in patient education, photo-documentation, preoperative planning and postsurgical evaluation in plastic surgeries. It has long been serving as a bridge that facilitated communication not only between patients and doctors, but also among plastic surgeons from different countries. Although several basic principles and photographic methods have been proposed, there is no internationally accepted photography that could provide both static and dynamic information in blepharoplasty. In this article, we introduced a novel six-position, frontal view photography for thorough assessment in blepharoplasty. METHODS: From October 2013 to January 2017, 1068 patients who underwent blepharoplasty were enrolled in our clinical research. All patients received six-position, frontal view photography. Pictures were taken of the patients looking up, looking down, squeezing, smiling, looking ahead and with closed eyes. Conventionally, frontal view photography only contained the last two positions. Then, both novel six-position photographs and conventional two-position photographs were used to appraise postsurgical outcomes. RESULTS: Compared to conventional two-position, frontal view photography, six-position, frontal view photography can provide more detailed, thorough information about the eyes. It is of clinical significance in indicating underlying adhesion of skin/muscle/fat according to individual's features and assessing preoperative and postoperative dynamic changes and aesthetic outcomes. CONCLUSION: Six-position, frontal view photography is technically uncomplicated while exhibiting static, dynamic and detailed information of the eyes. This innovative method is favorable in eye assessment, especially for revision blepharoplasty. We suggest using six-position, frontal view photography to obtain comprehensive photographs. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Strategies of Mandibular Revision: A Retrospective Study of Revisional Mandibular Surgery for Unaesthetic Results of Previous Mandibular Reduction.

BACKGROUND: Mandibular reduction has been developed and popularized in Asia for decades. Despite the technical advancement and experience accumulation, complications and unaesthetic results still occur, and some need a revision surgery. This study aims to introduce the experience of revision surgery to reshape the unaesthetic mandibular contour after previous mandibular reduction. METHODS: From May 2011 to September 2017, patients dissatisfied with the result of previous mandibular reduction and who received a secondary mandibular revision were retrospectively reviewed and analyzed. RESULTS: Twenty-five patients were included in this study. Under-correction (88%, 22/25) was the most common aesthetic problem requiring revision, followed by asymmetry (56%, 14/25), broad chin (40%, 10/25), second mandibular angle (32%, 8/25), and over-correction (8%, 2/25). As revision techniques, long-curve mandibular reduction, simple mandibular reduction, and mandibular grinding were performed on 60% (15/25), 36% (9/25), and 4% (1/25) of the patients, respectively. All the patients were satisfied with the results. Cephalometric measurements indicated a significant bone removal after revision. CONCLUSIONS: When performing a revision surgery to reshape the mandibular contour, the surgeon should have a clear surgical plan based on comprehensive evaluation, focus on the balanced harmony of the entire face, use proper technique and instruments, and avoid concomitant injury and complications. The one-staged technique that treats the whole mandible as an entirety is superior than multistaged techniques to improve the aesthetic outcomes to the largest extent. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The Epoxidation of Carbonyl Compounds with a Benzyne-Triggered Sulfur Ylide.

An efficient method for the synthesis of epoxides from carbonyl compounds, sulfoxides, and benzyne is presented. The strategy involved an epoxidation by a sulfur ylide which is formed in situ from sulfoxide and benzyne through the S-O bond insertion and deprotonation. This one-pot reaction proceeds under mild and base-free conditions, providing a convenient way to introduce the substituted methylene groups onto the carbonyl carbon.

Concentrations and seasonal variation of ambient PM(2.5) and associated metals at a typical residential area in Beijing, China.

In this study, continuous monitoring of PM2.5 was carried out for 1 year period at one of the largest residential areas in Beijing. Annual mean of PM2.5 during sampling period was 100.4 µg/m(3). The seasonal variation trend of PM2.5 was winter > spring > autumn and summer. The total mass concentrations of metals in PM2.5 ranged from 0.4 to 13.2 µg/m(3). There were significant (p < 0.05) seasonal variations for concentrations of Ca, Al, Mn, As, Rb, Cr, Ni, Cd and Co, seasonal variations in PM-associated metals were not necessarily the same as the seasonal variation in PM2.5, related to differing seasonal trends in source types. The impact of meteorological factors (e.g., wind speed) on metals levels of PM2.5 was found to be significant by regression models. The EFs value of Ag, Ca, Cd, Pb, Zn, As, Cu, and Cr were higher than ten, suggesting that those elements were primarily contributed by anthropogenic sources. Seasonal characteristic of EFs were found for As, Cr, Ca and Ag, which indicating the seasonal pollution sources types for those metals. Overall, these findings indicated that the pollution control of ambient PM2.5 should not be negligible in residential area in Beijing and the local government should pertinent and accurate prevent and control of air pollution as well as protect human health.

Would hyaluronic acid-induced mental bone resorption be a concern? A prospective controlled cohort study and an updated retrospective cohort study.

BACKGROUND: Hyaluronic acid (HA) is a widely used filler for face contouring and is generally believed to be safe and effective. However, there have been reports of HA-related bone erosion in the chin area without clear scientific data regarding its existence, incidence, and severity. This exploratory study was to evaluate HA-related mental bone resorption through a prospective, controlled, observer-blind, nonrandomized clinical trial and a retrospective cohort study. METHODS: On the one hand, a prospective, controlled, nonrandomized, single-shot HA-injection clinical trial was conducted. Computed tomographic scans were collected at baseline and at 6-12 months of follow-up for both HA-injection and control groups. On the other hand, an updated retrospective cohort study compared the HA-injection with a blank control group. The primary outcomes composed of three quantitative parameters [bone resorption index (BRI M and BRI N ), bone resorption thickness ratio] and one subjective evaluation index (severity ranking). Information about demographics, complications, and injection volume were also recorded. RESULTS: From June 2021 to March 2023, 78 patients were prospectively recruited for the study. There was a significant association between HA-injection and bone resorption [BRI M : pre (84.24±8.10%) vs post (79.21±8.70%), P <0.001; BRI N : pre 92.50% (73, 144%) vs 87.99% (63, 132%), P <0.001; bone thickness ratio: HA 24.08% (0, 48%) vs control 0 (0, 17%), P <0.001]. However, there was no difference in large-volume (>1 ml) and small-volume (≦1 ml) injection subgroups [bone resorption thickness ratio: (21.50±10.91%) vs (24.51±11.92%), P =0.350]. The imaging manifestation revealed discernible bone resorption in 35.90% of the patients, with an median bone resorption thickness ratio of 24.08%. Between October of 2019 and March 2023, 95 HA-injection patients (190 semimandibular cases), 95 normal controls were enrolled. The BRI M was significantly lower in the HA-injection group compared to the controls ( P <0.001). CONCLUSIONS: HA may induce bone resorption in the mentum. Large-scale randomized controlled clinical trial is warranted for further confirmation. Patients should be informed of this potential complication.