2-Pyran-4-Ylidene Malononitrile Based Conjugated Microporous Polymers as Metal-Free Heterogeneous Photocatalysts for Organic Synthesis.

Photoactive conjugated microporous polymers (CMPs) as heterogeneous photocatalysts provide a sustainable alternative to classical metal-based semiconductor photosensitizers. However, previously reported CMPs are typically synthesized through metal catalyzed coupling reactions, which bears product separation, but also increases the price of materials. Herein, a new type of sp2 carbon linked DCM-CMPs are successfully designed and synthesized by organic base catalyzed Knoevenagel reaction using 2,6-Dimethyl-4H-pyran-4-ylidene-malononitrile and aromatic polyaldehydes as monomers. The new polymers feature inherent porosity, excellent stability, and fully π-conjugated skeleton with broad visible-light absorption. They effectively induce the synthesis of benzimidazole compounds under light irradiation, and exhibit wide substrate adaptability with outstanding recyclability.

Transfer Patterns and Clinical Applications of the Forehead Flaps Based on the Supratrochlear Artery and Supraorbital Artery.

This study aimed to describe the application of transferring preexpanded forehead flaps based on the supratrochlear and supraorbital arteries in 3 patterns for facial reconstruction: Pattern I, interpolated flap; Pattern II, island flap; and Pattern III, propeller flap, which was subdivided into direct propeller flap (Pattern IIIa) and indirect propeller flap (Pattern IIIb). During the first stage, a tissue expander was inserted underneath the forehead. After sufficient inflation of the expander, a forehead flap based on the supratrochlear or supraorbital artery was elevated and transferred to reconstruct the facial defects. Three weeks after the surgery, pedicle division was performed, in which Pattern I and Pattern IIIb flaps were used. Twenty-four patients underwent facial reconstruction. Twenty-three flaps survived without any perfusion-related complications. Venous congestion developed in an island flap. All patients were followed up after surgery, ranging from 2 to 156 (mean, 19) months. The color and texture of the flap matched those of the adjacent skin. The patients and their families were satisfied with the final functional and esthetic outcomes. The forehead flap based on the supratrochlear and supraorbital arteries provides reliable coverage of facial defects. The conventional interpolated flap continues to be the most dependable. Single-stage reconstruction using the island flap and direct propeller flap is applicable to patients who decline the pedicle division procedure. The novel technique of using the indirect propeller flap is safe for cheek reconstruction with minimal donor-site morbidity and esthetically pleasing results.

Dual Role of Interleukin-20 in Different Stages of Osteoclast Differentiation and Its Osteoimmune Regulation during Alveolar Bone Remodeling.

Osteoimmunology mediators are critical to balance osteoblastogenesis and osteoclastogenesis to maintain bone homeostasis. A lot of the osteoimmunology mediators are regulated by interleukin-20 (IL-20). However, little is known about the role of IL-20 in bone remodeling. Here, we showed that IL-20 expression was correlated with osteoclast (OC) activity in remodeled alveolar bone during orthodontic tooth movement (OTM). Ovariectomize (OVX) in rats promoted OC activity and enhanced IL-20 expression, while blocking OC inhibited IL-20 expression in osteoclasts. In vitro, IL-20 treatment promoted survival, inhibited apoptosis of the preosteoclast at the early stages of osteoclast differentiation, and boosted the formation of osteoclasts and their bone resorption function at the late stages. More importantly, anti-IL-20 antibody treatment blocked IL-20-induced osteoclastogenesis and the subsequent bone resorption function. Mechanistically, we showed that IL-20 synergistically acts with RANKL to activate the NF-κB signaling pathway to promote the expression of c-Fos and NFATc1 to promote osteoclastogenesis. Moreover, we found that local injection of IL-20 or anti-IL-20 antibody enhanced osteoclast activity and accelerated OTM in rats, while blocking IL-20 reversed this phenomenon. This study revealed a previously unknown role of IL-20 in regulating alveolar bone remodeling and implies the application of IL-20 to accelerated OTM.

Virtual reality used in undergraduate orthodontic education.

INTRODUCTION: Undergraduate dental students frequently have reduced clinical experience which presents a challenge for their dental education. Previously, we developed a virtual reality (VR) simulating the whole clinical treatment process of a patient with angle Class II division 1 malocclusion, and the VR also helped to explain some important orthodontic concepts. As a novel teaching tool, this study aims to compare the effects of VR versus traditional case analysis by Power Point (PPT) in inspiring student learning motivation and evaluating learning experience. MATERIALS AND METHODS: A randomized, cross-over, stratified sampling method was taken to divide the fourth-year undergraduate dental students equally into two groups. The two groups were crossed over to use VR and PPT. RESULTS: For the whole study, results indicated that students in the VR group showed higher learning motivation (including attention, relevance, confidence and satisfaction) than in the PPT group, but the differences between VR and PPT groups were not very big, and the median of the differences located at 0. For learning experience, students thought VR to be more useful, more enjoyable and more engaging, but the median of differences also located at 0. Notably, the majority of students had higher recommendations for VR than PPT, and the median difference located at 1. However, when the two phases were analysed separately, some items showed no significant differences between VR and PPT learning. CONCLUSION: VR is a very useful adjunct to education compared to traditional case analysis by PPT, but we cannot exaggerate its benefits. Educators should make good use of VR to solve the difficult problems in education.

Use of Serial Flap Transfer Technique in En Bloc Reconstruction of Extensive Soft Tissue Defects in the Head and Neck.

ABSTRACT: En bloc reconstruction of extensive head and neck defects is feasible with matched tissue from the medial arm or chest. Nevertheless, the donor site faces significant morbidity following massive cutaneous flap harvesting. The serial flap transfer technique can increase the reconstructive ability of these flaps and minimize the donor site morbidity. A retrospective review was conducted from 2016 to 2020 on all patients who had undergone extensive head and neck reconstruction with the serial flap transfer technique. En bloc reconstruction of defects in the head and neck was performed using expanded perforator-plus flaps from the medial arm or chest; various flaps from the back were used to close the donor-site defects. Flap type, flap survival, complications, and revision procedures were assessed. This case series included 16 patients. The donor site of the chest or medial arm was successfully closed with the assistance of the thoracodorsal artery perforator flap, the latissimus dorsi myocutaneous flap, ortheparascapular flap. A medial arm flap with a width of 15 cm and a chest flap with a 16 cm width could be transferred with the primary closure of the donor sites. All flaps survived, except 1 had marginal necrosis. Complications occurred in 2 patients and were successfully managed nonsurgically. Both the recipient and donor sites were restored with good aesthetic results. Application of the serial flap transfer technique in extensive head and neck reconstruction decreases the donor site morbidity to a minimum and improves the overall outcomes.

Vertical Midface Lifting: An Improved Technique for Asians.

BACKGROUND: Treatment of the aging midface is increasingly deemed a key part of facial and periorbital rejuvenation. Compared with Westerners, Asians tend to have a relatively prominent zygoma and mandibular angle, thicker dermis, and greater propensity for scar formation. OBJECTIVE: This study was performed to review our surgical method of vertical midface lifting in Asian patients and evaluate the clinical outcomes. METHODS AND MATERIALS: This retrospective observational study involved 116 Asian women who complained of an aged midface. All patients underwent midface rejuvenation surgery with one lower eyelid incision and 2 small frontal-temporal incisions. Clinical results were assessed objectively using photographs and subjectively by a patient satisfaction survey. RESULTS: All patients recovered well without major complications. High patient satisfaction (94%) was attained. The improvement scores as evaluated by the panel demonstrated a higher level of improvement for the malar eminence (8.3 ± 0.6), nasojugal groove (8.0 ± 0.8), and nasolabial fold (7.9 ± 0.7) than for the lower face (6.2 ± 1.0). CONCLUSION: Our vertical midface lift technique is safe and effective for older Asian patients with a midface aging appearance. LEVEL OF EVIDENCE: Therapeutic IV.

Strontium Ranelate Inhibits Osteoclastogenesis through NF-κB-Pathway-Dependent Autophagy.

Strontium ranelate (SR) is a pharmaceutical agent used for the prevention and treatment of osteoporosis and fragility fracture. However, little attention has been paid to the effect of SR on alveolar bone remodeling during orthodontic tooth movement and its underlying mechanism. Here, we investigated the influence of SR on orthodontic tooth movement and tooth resorption in Sprague-Dawley rats and the relationship between the nuclear factor-kappa B (NF-κB) pathway, autophagy, and osteoclastogenesis after the administration of SR in vitro and in vivo. In this study, it was found that SR reduced the expression of autophagy-related proteins at the pressure side of the first molars during orthodontic tooth movement. Similarly, the expression of these autophagy-related proteins and the size and number of autophagosomes were downregulated by SR in vitro. The results also showed that SR reduced the number of osteoclasts and suppressed orthodontic tooth movement and root resorption in rats, which could be partially restored using rapamycin, an autophagy inducer. Autophagy was attenuated after pre-osteoclasts were treated with Bay 11-7082, an NF-κB pathway inhibitor, while SR reduced the expression of the proteins central to the NF-κB pathway. Collectively, this study revealed that SR might suppress osteoclastogenesis through NF-κB-pathway-dependent autophagy, resulting in the inhibition of orthodontic tooth movement and root resorption in rats, which might offer a new insight into the treatment of malocclusion and bone metabolic diseases.

Stiffness-tuned and ROS-sensitive hydrogel incorporating complement C5a receptor antagonist modulates antibacterial activity of macrophages for periodontitis treatment.

Periodontitis is admittedly a microbe-driven intractable infectious disease, in which Porphyromonas gingivalis (Pg) plays a keystone role. Pg can selectively impair the antimicrobial responses of periodontal resident macrophages including their phagocytic and bactericidal activity without interfering their proinflammatory activity, which leads to microflora disturbance, destructive periodontal inflammation and alveolar bone loss eventually. Here, an injectable ROS-sensitive hydrogel is developed for releasing active bone marrow-derived macrophages (named ex-situ macrophages hereafter) and a complement C5a receptor antagonist (C5A) to the gingival crevice. Through appropriately tuning the hydrogel stiffness, the phagocytic activity of these macrophages is greatly enhanced, reaching an optimal performance at the elastic modulus of 106 kPa. Meanwhile, C5A avoids undesired C5a receptor activation by Pg to ensure the bacterial killing activity of both the ex-situ and in-situ macrophages. Besides, the ROS-sensitive hydrogels show another distinct feature of decreasing the ROS level in periodontal niche, which contributes to the alleviated periodontal inflammation and attenuated bone loss as well. This study highlights the potential of utilizing hydrogels with tailored biomechanical properties to remodel the functions of therapeutic cells, which is expected to find wide applications even beyond periodontitis treatment.

Status and changes of water quality in typical near-city zones of three East African Great Lakes in Tanzania.

Tanzania is the only country bordering all three transboundary East African Great Lakes, i.e., Lake Victoria, Lake Tanganyika, and Lake Nyasa (Lake Malawi). This study investigated the spatiotemporal variability of basic physicochemical parameters of nearshore surface waters in Mwanza Gulf (Lake Victoria), Kigoma Bay (Lake Tanganyika), and Wissmann Bay (Lake Nyasa). Water quality was evaluated using the water quality index (WQI) method. Results showed that N and P nutrient pollution was relatively severe in central and southern parts of Mwanza Gulf owing to external agricultural emissions and internal release associated with physically disturbed sediment resuspension. External inputs from inflowing surface runoffs from the city of Mwanza typically enhanced N loading in northern parts of the gulf during the rainy season. Poor water quality was found in central and southern parts of Mwanza Gulf, especially in the rainy season. Algal blooms and NH4+-N (total P and total N) were the main factors driving water quality degradation in the rainy (dry) season. Kigoma Bay and Wissmann Bay both had good water quality, except in river mouth areas in Lake Nyasa during the rainy season. The degradation in water quality was caused primarily by increased land-based nutrient and turbidity inputs. To respond to challenges associated with climate change and local socioeconomic development, long-term monitoring of the lacustrine environment and systematic limnological studies will be required, not only in the three bays but also more widely throughout the three lakes and their basins.

Interleukin-20 Acts as a Promotor of Osteoclastogenesis and Orthodontic Tooth Movement.

OBJECTIVES: Bones constitute organs that are engaged in constant self-remodelling. Osteoblast and osteoclast homeostasis during remodelling contribute to overall skeletal status. Orthodontics is a clinical discipline that involves the investigation and implementation of moving teeth through the bone. The application of mechanical force to the teeth causes an imbalance between osteogenesis and osteogenesis in alveolar bone, leading to tooth movement. Osteoimmunology comprises the crosstalk between the immune and skeletal systems that regulate osteoclast-osteoblast homeostasis. Interleukin- (IL-) 20, an IL-10 family member, is regarded as a proinflammatory factor for autoimmune diseases and has been implicated in bone loss disease. However, the mechanism by which IL-20 regulates osteoclast differentiation and osteoclastogenesis activation remains unclear. This study investigated the effects of IL-20 on osteoclast differentiation in a rat model; it explored the underlying molecular mechanism in vitro and the specific effects on orthodontic tooth movement in vivo. METHODS: For in vitro analyses, primary rat bone marrow-derived macrophages (BMMs) were prepared from Sprague-Dawley rats for osteoclast induction. After BMMs had been treated with combinations of recombinant IL-20 protein, siRNA, and plasmids, the expression levels of osteoclast-specific factors and signalling pathway proteins were detected through real-time polymerase chain reaction, western blotting, and immunofluorescence staining. For in vivo analyses, IL-20 was injected into the rat intraperitoneal cavity after the establishment of a rat orthodontic tooth movement (OTM) model. OTM distance was detected by Micro-CT and HE staining; the expression levels of protein were detected through immunofluorescence staining. RESULTS: In vitro analyses showed that a low concentration of IL-20 promoted preosteoclast proliferation and osteoclastogenesis. However, a high concentration of IL-20 inhibited BMM proliferation and osteoclastogenesis. IL-20 knockdown decreased the expression of osteoclast specific-markers, while IL-20 overexpression increased the expression of osteoclast specific-markers. Furthermore, IL-20 regulated osteoclast differentiation through the OPG/RANKL/RANK pathway. Overexpression of IL-20 could significantly upregulate RANKL-mediated osteoclast differentiation and osteoclast specific-marker expression; moreover, RANKL/NF-κB/NFATc1 acted as downstream signalling molecule for IL-20. In vivo analysis showed that OTM speed was significantly increased after intraperitoneal injection of IL-20; additionally, mechanical stress sensing proteins were markedly activated. CONCLUSIONS: IL-20 augments osteoclastogenesis and osteoclast-mediated bone erosion through the RANKL/NF-κB/NFATc1 signalling pathway. IL-20 inhibition can effectively reduce osteoclast differentiation and diminish bone resorption. Furthermore, IL-20 can accelerate orthodontic tooth movement and activate mechanical stress sensing proteins.

Simultaneous qualitation and quantitation of natural trans-1,4-polyisoprene from Eucommia ulmoides Oliver by gel permeation chromatography (GPC).

Natural trans-1,4-polyisoprene (TPI) as a functional biomaterial has aroused great interest for rubber industrial product use. Here, we proposed a method that enables simultaneous analysis of the content and molecular-weight distribution (MWD) of natural TPI by gel permeation chromatography (GPC). The natural TPIs were collected from leaves, fruit coatings and bark of Eucommia ulmoides Oliver (E. ulmoides) through toluene extraction followed by ethanol purification. The results of TPI contents from leaves and fruit coatings were shown ca. 3.5% and 13.8%, respectively. Accordingly, limits of detection (LODs) of TPI were 0.58mg/mL from leaves and 0.47mg/mL from fruit coatings. The MWDs of TPI demonstrated a bimodal distribution from leaves, a unimodal distribution from bark, and a unimodal distribution with a tiny peak shoulder from fruit coatings. In real-life E. ulmoides analysis, the results from three independent methods (GPC, gravimetric method, and infrared spectroscopy) were obtained with good consistency.

[The penis prolongation and augmentation combined with autologous granular fat injection and silicone implantation].

OBJECTIVE: To prevent the retraction of the penis after prolongation and augmentation. METHODS: After all the superficial and part of the deep suspensory ligament amputation, we implanted the silicon sheet (the length 2.3-3.6 cm, the width 1.5-2.5 cm, the thickness 2-3 mm) and injected autologous granular fat (30-48 ml) into penis. RESULTS: 16 patients (age 22-63 years, averagely 38 years) underwent this kind operation, the prolongation length is 1.8-5.1 cm, the average was 2.91 cm, the increased diameter of penis was 0.6-1 cm, the average is 0.85 cm, the following period is 3 months to 2 years. The results are satisfactory with the penis retraction less than 8%, and less than 10% decrease in diameter. CONCLUSIONS: This method is an ideal way of the penis prolongation and augmentation, the implantation of the silicon sheet is effective way to prevent the retraction of the penis.

[Evaluation of the facial artery and vein using color Doppler imaging].

OBJECTIVE: The purpose of this study was to provide the guidelines with respect to the location of the facial vessels, observe the potential reversed flow of the facial artery, and reemphasize the value of color Doppler ultrasound studies in flap planning. METHODS: A study was carried out to investigate the location and dynamics of the facial artery and vein using color Doppler ultrasonography in 12 adults. RESULTS: The facial artery and the vein were located together at the lower border of the mandible. Around the oral commissure and under the nasal ala, they run apart from each other at variable distances. The reverse flow was observed in the 12 patients after the blood flow of the facial artery was blocked by applying pressure manually at the lower border of the mandible. CONCLUSIONS: The divergence of the facial vein from the artery is important information in planning of axial pattern flaps. Observation of the reversed flow confirms the possibility of safe elevation of a retrograde flow-arterialized flap based on the distal portion of the facial artery.