High-Resolution Imaging Study on Photodissociation of OCS+ [A2ΠΩ=1/2,3/2 (ν1 0 ν3)].

The development of the velocity map ion imaging (VMI) technique has greatly advanced the study of photodissociation dynamics. The high-resolution imaging study of the photodissociation allows for the acquisition of precise and detailed information on the fragments. This information can further provide more insight into the energy partition and potential pathways involved in the photodissociation process. In this study, we report the investigation on the photodissociation of OCS+ via the A2ΠΩ=1/2,3/2 states following the excitation of A2Π (ν1 0 ν3) ← X2Π (0 0 0) by using time-sliced VMI techniques in the ultraviolet region. Our investigation revealed significant mode-dependent recoil anisotropies and branching ratios of two product channels for both Ω = 1/2 and Ω = 3/2. The photolysis products also exhibited dramatic deviation in angular distributions and generally comparable kinetic energy distributions following the excitation to the same vibrational modes of A2ΠΩ states with two separate spin-orbit components. According to the observation in this study and previously reported photodissociation mechanisms of the OCS+ cations, the decay from the A2Π3/2 state was more likely via the internal conversion to high rovibrational states of the X2Π state, in comparison to the A2Π1/2 state.

Vibrational state-specific nonadiabatic photodissociation dynamics of OCS+ via A2Π1/2 (ν1 0 ν3) states.

The identification and analysis of quantum state-specific effects can significantly deepen our understanding of detailed photodissociation dynamics. Here, we report an experimental investigation on the vibrational state-mediated photodissociation of the OCS+ cation via the A2Π1/2 (ν1 0 ν3) states by using the velocity map ion imaging technique over the photolysis wavelength range of 263-294 nm. It was found that the electronically excited S+ product channel S+(2Du) + CO (X1Σ+) was significantly enhanced when the ν1 and ν3 vibrational modes were excited. Clear deviations in the branching ratios of the electronically excited S+ channel were observed when the vibrational modes ν1 and ν3 were selectively excited. The results reveal that vibrationally excited states play a vital role in influencing the nonadiabatic couplings in the photodissociation process.

In Vitro Induction of Human Dental Pulp Stem Cells to Lymphatic Endothelial Cells.

Lymphedema is a progressive and irreversible disease due to the lymphatic system disorder. Conservative and surgical therapies are either ineffective or impractical. Currently, mesenchymal stem cells (MSCs)-based therapies seem to be the most promising treatment for lymphedema. The MSCs promote lymphangiogenesis through the paracrine approach or by directly differentiating into lymphatic endothelial cells (LECs) under the induction of growth factors. Human dental pulp stem cells (hDPSCs) have been suggested to play important roles in tissue regeneration, making it an attractive candidate for the lymphedema treatment. In this study, to evaluate the potential role of hDPSCs in the clinical application for lymphedema treatment, we induced the hDPSCs with vascular endothelial growth factor-C (VEGF-C) and investigated the lymphangiogenic differentiation potential of hDPSCs in vitro. We found that under the VEGF-C induction, hDPSCs demonstrated upregulated LECs specific markers, promoted cell proliferation and migration, and increased tube formation, all of which contributed to their differentiation into LECs in vitro.

Yes-associated protein promotes bone healing after tooth extraction in mice.

In this study, a tooth extraction socket model was established in vivo, and Lv-YAP1-GFP, Lv-GFP or saline was injected locally into the extraction socket. Expression of markers of osteogenesis, osteoclastogenesis, adipogenesis, proliferation and apoptosis explore whether YAP can promote bone formation in the process of tooth extraction socket healing. 66 BALB/c mice were divided into 3 groups and underwent left maxillary first molar extraction, Lv-YAP1-GFP, Lv-GFP or saline was injected into the tooth extraction socket. The maxilla was harvested 1, 3, 7, and 10 days after operation for subsequent analysis by Micro-CT and immunohistochemical analysis. Quantitative analysis of the expression of TRAP, ALP, BMP2, RUNX2, Osterix, OCN, RANKL, PPARγ, and PCNA was conducted. The results of immunofluorescence showed that the lentivirus was successfully transfected into the extraction socket. On the middle and last stage of tooth extraction healing, results of Micro-CT showed that the BV/TV, Tb.Th and Tb.N were significantly higher in the experimental group, results of immunohistochemistry showed that the overexpression of YAP increase in the expression of BMP2, ALP, RUNX2, Osterix, OCN, and PCNA. The expression of PPARγ and TUNEL staining results were significantly lower in the experimental group. The expression of TRAP and RANKL showed no significant differences among the 3 groups. We conclude that YAP could promote bone formation in the middle and late stages of tooth extraction socket healing. The overexpression of YAP increased bone formation and cell proliferation, decreased adipogenic differentiation and apoptosis.

Periosteal Skeletal Stem Cells and Their Response to Bone Injury.

Bone exhibits remarkable self-repair ability without fibrous scars. It is believed that the robust regenerative capacity comes from tissue-resident stem cells, such as skeletal stem cells (SSCs). Roughly, SSC has two niches: bone marrow (BM) and periosteum. BM-SSCs have been extensively studied for years. In contrast, our knowledge about periosteal SSCs (P-SSCs) is quite limited. There is abundant clinical evidence for the presence of stem cell populations within the periosteum. Researchers have even successfully cultured "stem-like" cells from the periosteum in vitro. However, due to the lack of effective markers, it is difficult to evaluate the stemness of real P-SSCs in vivo. Recently, several research teams have developed strategies for the successful identification of P-SSCs. For the first time, we can assess the stemness of P-SSCs from visual evidence. BM-SSCs and P-SSCs not only have much in common but also share distinct properties. Here, we provide an updated review of P-SSCs and their particular responses to bone injury.

Application of ultrasound guidance in the oral and maxillofacial nerve block.

INTRODUCTION: Nerve block technology is widely used in clinical practice for pain management. Conventional nerve localization methods, which only rely on palpation to identify anatomical landmarks, require experienced surgeons and can be risky. Visualization technologies like ultrasound guidance can help prevent complications by helping surgeons locate anatomical structures in the surgical area and by guiding the operation using different kinds of images. There are several important and complex anatomical structures in the oral and maxillofacial regions. The current article reviews the application of ultrasound guidance in oral and maxillofacial nerve blocks. METHODS: We searched the literature on the use of ultrasound guidance for the main nerve block techniques in the oral and maxillofacial regions using both PubMed and MEDLINE and summarized the findings. RESULTS AND DISCUSSION: A review of the literature showed that ultrasound guidance improves the safety and effectiveness of several kinds of puncture procedures, including nerve blocks. There are two approaches to blocking the mandibular nerve: intraoral and extraoral. This review found that the role of ultrasound guidance is more important in the extraoral approach. There are also two approaches to the blocking of the maxillary nerve and the trigeminal ganglion under ultrasound guidance: the superazygomatic approach and the infrazygomatic approach. The infrazygomatic approach can be further divided into the anterior approach and the posterior approach. It is generally believed that the anterior approach is safer and more effective. This review found that the effectiveness and safety of most oral and maxillofacial nerve block operations can be improved through the use of ultrasound guidance.

Dental follicles promote soft tissue management in surgical exposure of labially impacted maxillary canine.

BACKGROUND: The present study aimed to report a technically improved operation on the surgical exposure of labially impacted maxillary canine, elaborating the management of soft tissue to achieve better aesthetic results, and post-treatment periodontal health. METHODS: Patients sought orthodontic treatment with unilateral labially impacted maxillary canines were selected in this study. The impacted teeth were assigned to the experimental group and contralateral unimpacted canines were assigned to the control group. The impacted canines were surgically exposed with dissected dental follicle (DF) stitching to muscle and mucosa surrounding the crowns. The gingival index (GI), probing depth (PD), the width of the keratinized gingiva (WKG), gingival scars (GS), bone loss (BL), and apical root resorption (ARR) were recorded after the removal of the fixed appliance. A two-sample t-test was used for independent samples for parametric variables. RESULTS: A total of 24 patients with unilateral maxillary canine impaction were successfully treated. The outcomes of GI, WKG, GS, BL, and ARR did not indicate statistical significance between the experimental group and the control group. CONCLUSIONS: The preservation of DF promotes soft tissue management in combined surgical and orthodontic treatment of labially impacted maxillary canine to achieve better periodontal status. Trial Registration Chinese Clinical Trial Registry ChiCTR2000029091, 2020-01-12.

Wnt Signaling Regulates the Lymphatic Endothelial Transdifferentiation of Adipose-Derived Stromal Cells In Vitro.

Lymphedema is a chronic, progressive disease that causes pain as well as heavy economic burdens to patients. Reconstruction of the impaired lymphatic system is the key to treat lymphedema. Currently, there is no cure, but mesenchymal stromal cells show promising potential for lymphatic endothelial regeneration. Adipose-derived stromal cells (ADSCs) have been proved to support lymphangiogenesis both in vivo and in vitro. However, the mechanism in vascular endothelial growth factor C-induced (VEGF-C-induced) lymphatic endothelial transdifferentiation of ADSCs remains unknown. In this study, we show a novel link between the Wingless and int-1 (Wnt) pathway and the lymphatic endothelial differentiation process. We used LiCl to activate Wnt and DKK-1 to inhibit Wnt. Compared with the Wnt inhibition group and the control groups, the Wnt activation group produced more lymphatic endothelial cell (LEC)-related mRNA and proteins. Besides, Wnt-activated ADSCs formed longer tubes in two-dimensional culture and promoted the growth of lymphatic vessels in a three-dimensional transwell ADSC-LEC co-culture system. Our results demonstrated that activation of Wnt during the lymphatic endothelial transdifferentiation of ADSCs would enhance the efficacy of VEGF-C treatment. We anticipate our assay to expand our knowledge of Wnt in cell transdifferentiation and lay a foundation for future efforts to explore a novel and effective ADSC-based therapy for lymphedema.

Trajectories of Idea Emergence in Dialogic Collaborative Problem Solving: Toward a Complex Dynamic Systems Perspective.

According to the complex dynamic systems (CDS) perspective, learning emerges at various system levels. This study built a coherent theoretical framework based on CDS and Bakhtinian dialogic theory and further employed the concept of attractor (i.e., certain stable states that recur over time) in CDS theory to investigate the trajectories of idea emergence and how they diversified group outcomes in dialogic collaborative problem solving (D-CPS). Two contrasting groups were compared using visual and qualitative analysis approaches. The analysis based on idea tree diagrams showed that new ideas emergent in group discussion tended to attract local utterances and performed features of attractors in CDS in both high-performing and low-performing groups. The analysis based on idea hierarchy diagrams revealed how ideas emerged at various system levels. It was also found that status problems were likely to affect the functioning of regulative feedback loops, which might give rise to different structures of idea evolution. This study proposed CDS theory as an alternative perspective, augmented by the ethical considerations of Bakhtinian dialogism, for examining the dynamics of D-CPS.

Interleukin-4-loaded hydrogel scaffold regulates macrophages polarization to promote bone mesenchymal stem cells osteogenic differentiation via TGF-ß1/Smad pathway for repair of bone defect.

OBJECTIVE: Tissue engineering is a promising strategy for repair of large bone defect. However, the immune system reactions to biological scaffold are increasingly being recognized as a crucial factor influencing regeneration efficacy. In this study, a bone-bioactive hydrogel bead loaded with interleukin-4 (IL-4) was used to regulate macrophages polarization and accelerate bone regeneration. METHODS: IL-4-loaded calcium-enriched gellan gum (Ca-GG + IL-4) hydrogel beads were synthesised. And the effect on cell behaviour was detected. Furthermore, the effect of the Ca-GG + IL-4 hydrogel bead on macrophage polarization and the effect of macrophage polarization on bone mesenchymal stem cells (BMSCs) apoptosis and osteogenic differentiation were evaluated in vitro and in vivo. RESULTS: BMSCs were able to survive in the hydrogel regardless of whether IL-4 was incorporated. Immunofluorescence staining and qPCR results revealed that Ca-GG + IL-4 hydrogel bead could promote M2 macrophage polarization and increase transforming growth factor (TGF)-ß1 expression level, which activates the TGF-ß1/Smad signalling pathway in BMSCs and promotes osteogenic differentiation. Moreover, immunohistochemical analysis demonstrated Ca-GG + IL-4 hydrogel bead could promote M2 macrophage polarization and reduce cell apoptosis in vivo. In addition, micro-CT and immunohistochemical analysis at 12 weeks post-surgery showed that Ca-GG + IL-4 hydrogel bead could achieve superior bone defect repair efficacy in vivo. CONCLUSIONS: The Ca-GG + IL-4 hydrogel bead effectively promoted bone defect regeneration via regulating macrophage polarization, reducing cell apoptosis and promoting BMSCs osteogenesis through TGF-ß1/Smad pathway. Therefore, it is a promising strategy for repair of bone defect.

Adipose-derived stem cell therapy shows promising results for secondary lymphedema.

Lymphedema is mainly identified by progressive soft tissue swelling in impaired lymphatic system. Secondary lymphedema attributed to cancer therapy, parasite infection, and trauma remains a serious global disease. Patients with lymphedema suffer swelling, pain, and fatigue, with the dysfunction of the deformed extremities reducing the quality of life and increasing the risk of infection and lymphangiosarcoma. Adipose-derived stem cells (ADSCs) possess prominent regenerative potential to differentiate into multilineage cells, and produce various lymphangiogenic factors, making ADSC therapy a promising approach for lymphedema. The development of lymphedema consists of local inflammation, the fibrosis of lymphatic vessels, and the deposition of adipose fat. Existing animal models do not mimic the chronic inflammation environment, therefore suitable models are required in further studies. Some signal pathways and molecular mechanisms in physiological and pathological lymphagiogenesis remain unclear. In previous animal and human trials, ADSC therapy reduced edema in varying degrees. A larger number of trials with larger samples and longer follow-up periods are required to verify the efficiency and feasibility of ADSC therapy. ADSCs are of easy availability and immune exemption, making them a candidate for lymphedema treatment. Whether ADSCs enhance malignant characteristics or trigger the malignant change deserves further exploration and study before ADSC therapy can be made widely available.

Tumor characteristics and surgical outcome in incidentally discovered pheochromocytomas and paragangliomas.

OBJECTIVE: The proportion of incidentally discovered pheochromocytomas and paragangliomas(PPGL) has increased over time. However, our knowledge of them is quite limited. The purpose of this retrospective study is to generalize the commonalities in incidentally discovered PPGL, offer evidences for clinical diagnosis and management. METHODS: 526 patients were included in our study after filtration from the database of West China Hospital of Sichuan University between May, 2007 and December, 2016.Among the patients, 148 of them were incidental findings and 378 of them were suspected findings. All patients' demography and tumor characteristics were recorded in detail, especially hemodynamic records and hormonal assays. The reasons for taking radiography were also collected. Most patients received preoperative medical preparation . Intraoperative and postoperative courses as well as surgical outcomes were also analyzed to identify differences between incidental findings and suspected findings. RESULTS: Incidentally discovered PPGL took up 28.1% of the study population. Suspected PPGLs had a higher prevalence of hypertension, lower proportion of non-functioning PPGL, higher prevalence of MEN2 and better post-surgical blood pressure recovery than incidental finding group. However, patients in the incidental finding group showed no significant difference in preoperative blood pressure and hormonal assays with suspected findings in metaphrine and normetaphrine in plasma and urine (P>0.05). CONCLUSIONS: Due to the development of technology, more PPGLs are discovered incidentally. Considering the tumor characteristics and surgical outcome, surgical decisions should be made more cautiously.

Preoperative selective vs non-selective α-blockade in PPGL patients undergoing adrenalectomy.

PURPOSE: Preoperative preparation for adrenalectomy for pheochromocytomas and paragangliomas (PPGL) is universally recognized as necessary, while the optimal strategy remains controversial. Our aims were to increase intraoperative hemodynamic stability, expedite postoperative recovery, decrease side effects and reduce costs for patients with PPGL undergoing adrenalectomy. METHODS: We identified 526 patients undergoing open adrenalectomy for PPGL in the West China Hospital of Sichuan University between May, 2007 and December, 2016. 149 patients received preoperative selective α-blockade with phenoxybenzamine, and 377 patients received non-selective α-blockade with prazosin, doxazosin or terazosin. There were no statistical differences between groups regarding preoperative patient and tumor characteristics. Operations were planned once hypertensive patients were well-controlled with blood pressure ≤130/85 mmHg. Intraoperatively, all patients received arterial blood pressure monitoring, and indwelling urinary catheters to record urine output. We recorded intraoperative hemodynamics, status in the postanesthesia or intensive care unit, postoperative recovery and complications. RESULTS: Patients in the non-selective group showed a more significant decline in postoperative systolic blood pressure than the selective group (P = 0.041). Also, patients in the non-selective group appeared to receive a long-term anti-hypertensive effect, especially for diastolic blood pressure (P = 0.037), which was a novel finding, based on the current literature. CONCLUSIONS: Our results confirmed that non-selective α-blockade produced a more significant anti-hypertensive effect than selective α-blockade. However, we found no significant difference in intraoperative hemodynamic instability, postoperative recovery and postoperative complications between groups.