Ultrafast photoinduced charge carrier dynamics of L-cysteine and oleylamine stabilized CsPbBr3 perovskite quantum dots coupled with gold nanoparticles.

We have synthesized L-cysteine and oleylamine stabilized CsPbBr3 perovskite quantum dots (PQDs) and coupled them with gold nanoparticles (AuNPs). The PQDs and AuNPs, as well as their hybrid nanostructures (HNS), were characterized using UV-visible (UV-vis) and photoluminescence (PL) spectroscopy. The UV-vis spectra show absorption bands of the HNS at 503 and 520 nm, attributed mainly to PQDs and AuNPs, respectively. The PQDs show a strong excitonic PL band peaked at 513 nm from PQDs. The HR-TEM results show the formation of hybrid structures between PQDs and AuNPs, which is also supported by the PL quenching of the PQDs by the coupled AuNPs. Ultrafast dynamics of the exciton and charge carriers in the HNS and pristine PQD were studied using femtosecond transient absorption. Multiexponential fitting of the dynamic data revealed the existence of shallow and deep trap states in pristine PQDs and ultrafast electron transfer from PQDs to AuNPs in the HNS. A kinetic model was proposed to account for the key dynamic processes involved and to extract the time for electron transfer from PQDs to AuNPs in the HNS, found to be ∼2 ps. Dynamic processes in pristine PQDs are largely unchanged by HNS formation with AuNPs.

[Early treatment of Class â ¢ malocclusion based on craniomaxillofacial growth and development].

More and more attention has been paid to the early treatment of malocclusion, especially the early treatment of class Ⅲ malocclusion. Class Ⅲ malocclusion not only affects maxillofacial growth and development, occlusal function and facial beauty, but also leads to serious physical and mental problems. Focusing on class Ⅲ malocclusion, the definition, classification, etiological mechanism, craniofacial growth and development rule, and the influence of early treatment on craniofacial growth and development were reviewed. In class Ⅲ patients, the craniofacial growth and development should be evaluated and analyzed when the early intervention carried out. The purpose of treatment of class Ⅲ malocclusion is achieved by using the appliance to affect the craniomaxillofacial growth.

[Effects of clear aligners combined with maxillary protractor on mixed dentition patient with skeletal class â ¢ malocclusion: a finite element study].

Objective: To compare the effects of expansion screw with maxillary protractor and clear aligners combined with maxillary protractor on the maxilla and maxillary dentition of mixed dentition patients with class Ⅲ skeletal malocclusion using finite element analysis, further providing clinical guidance for clear aligner treatment. Methods: A finite element model was established based on maxillofacial cone-beam CT data of a 10-year-old boy with mixed dentition, class Ⅲ skeletal malocclusion, who visited Department of Orthodontics, School of Stomatology, The Fourth Military Medical University in January, 2024. The expander with protractor group (group A) and the clear aligners with protractor group (group B) were divided. The arch was extended by 0.25 mm in both groups, and the forward pull force was 2.94 N (working condition 1) and 4.90 N (working condition 2), respectively. The initial displacement trend of maxilla and maxillary dentition in two groups under two working conditions were evaluated. Results: Under two working conditions, the maxilla of both groups showed clockwise rotation and labial inclination. The labial inclination of maxilla was more significant in clear aligners with protractor group, about 2.2-3.0 times that of expander with protractor group under the same working condition. Maxillary dentition showed mesial and buccal displacement, with anterior teeth extrusion and posterior teeth intrusion in two groups under two working conditions. Under the working condition 1 and 2, the labial displacement of central incisor of clear aligners with protractor group (-0.065, -0.089 mm) were greater than that in expander with protractor group (-0.024, -0.024 mm). Under two working conditions, the posterior teeth of expander with protractor group moved close to the buccal bodily direction, while those of clear aligners with protractor group moved tilted towards the buccal direction in the horizontal direction. The forward displacement trend of maxilla and maxillary dentition in clear aligners with protractor group was more obvious than expander with protractor group with the increase of the forward pull force. Under two working conditions, the anterior teeth' s hydrostatic stress of periodontal membrane and the equivalent stress of alveolar bone in clear aligners with protractor group were higher than those in expander with protractor group, mainly concentrated on the labial cervical region of the incisor. Conclusions: Clear aligners combined with maxillary protractor can produce forward force on the maxilla, but labial inclination occurs in the anterior teeth. It can be an effective orthopedic treatment strategy for mixed dentition patients with class Ⅲ skeletal malocclusion.

Formation of Linear Plasmonic Heterotrimers Using Nanoparticle Docking to DNA Origami Cages.

The fabrication of complex assemblies with interesting collective properties from plasmonic nanoparticles (NPs) is often challenging. While DNA-directed self-assembly has emerged as one of the most promising approaches to forming such complex assemblies, the resulting structures tend to have large variability in gap sizes and shapes, as the DNA strands used to organize these particles are flexible, and the polydispersity of the NPs leads to variability in these critical structural features. Here, we use a new strategy termed docking to DNA origami cages (D-DOC) to organize spherical NPs into a linear heterotrimer with a precisely defined geometrical arrangement. Instead of binding NPs to the exterior of the DNA templates, D-DOC binds the NPs to either the interior or the opening of a 3D cage, which significantly reduces the variability of critical structural features by incorporating multiple diametrically arranged capture strands to tether NPs. Additionally, such a spatial arrangement of the capture strand can work synergistically with shape complementarity to achieve tighter confinement. To assemble NPs via D-DOC, we developed a multistep assembly process that first encapsulates an NP inside a cage and then binds two other NPs to the openings. Microscopic characterization shows low variability in the bond angles and gap sizes. Both UV-vis absorption and surface-enhanced Raman scattering (SERS) measurements showed strong plasmonic coupling that aligned with predictions by electrodynamic simulations, further confirming the precision of the assembly. These results suggest D-DOC could open new opportunities in biomolecular sensing, SERS and fluorescence spectroscopies, and energy harvesting through the self-assembly of NPs into more complex 3D assemblies.

[Development and evaluation of the simplified Chinese versions of motion sickness susceptibility questionnaire].

Objective: To develop and evaluate the simplified Chinese versions of motion sickness susceptibility questionnaire (MSSQ)-long (MSSQ-L) and MSSQ-short (MSSQ-S). Methods: A cross-sectional study was conducted in May 2023 among 3 426 university students at North China University of Science and Technology. The Chinese versions of MSSQ-L and MSSQ-S were distributed, and item selection for Simplified Chinese versions of MSSQ-L and MSSQ-S was performed based on item response rates, item-total correlations, Cronbach's alpha coefficients, and standard deviations. Forty-five male and forty-five female participants were recruited from the initial survey population to complete Coriolis acceleration endurance testing and fill out the simplified Chinese versions of MSSQ-L and MSSQ-S, and Graybiel symptom severity score questionnaire. Internal consistency, external consistency, criterion validity, discriminant validity, and predictive accuracy for motion sickness severity were assessed. Results: A total of 3 111 valid responses were received for the Chinese versions of MSSQ, yielding an effective response rate of 90.8% (3 111/3 426). Among the 3 111 students surveyed, there were 965 males and 2 146 females, with a mean age of (19.5±1.4) years. The highest usage rates for item were observed for cars (98.9%, 3 077/3 111) and buses (98.8%, 3 073/3 111). The simplified Chinese versions of MSSQ-L and MSSQ-S consisted of four and eight items, respectively. The Cronbach's alpha coefficients were 0.900 and 0.953 for the simplified Chinese versions of MSSQ-S and MSSQ-L, respectively, with test-retest reliabilities of 0.895 and 0.908. Criterion validity coefficients were 0.814 and 0.765 for the simplified Chinese versions of MSSQ-S and MSSQ-L, respectively. In terms of discriminant validity, significant differences were observed between mild and moderate susceptibility groups [0(0, 3) vs 6(2, 10), P=0.006] and between moderate and severe susceptibility groups [6(2, 10) vs 9(6, 13), P=0.030] for the simplified Chinese version of MSSQ-S. Significant differences were also observed between mild and moderate susceptibility groups [5(0, 3) vs 7(3, 10), P=0.001], but not between moderate and severe susceptibility groups [7(3, 10) vs 7(3, 10), P=0.081] for simplified Chinese version of MSSQ-L. The overall predictive accuracy for motion sickness severity improved from 55.6% (50/90) to 62.2% (56/90) for the simplified Chinese version of MSSQ-S and from 54.4% (49/90) to 58.9% (53/90) for the simplified Chinese version of MSSQ-L, but with no statistically significant differences (both P>0.05). Conclusions: The simplified Chinese versions of MSSQ-L and MSSQ-S demonstrates good reliability and validity. The simplified Chinese version of MSSQ-S exhibits satisfactory discriminant validity, and can serve as a simple and efficient tool for assessing motion sickness susceptibility.

Photocycloaddition of Zero-Dimensional Metal Halide Hybrids with Reversible Photochromism.

In this work, two zero-dimensional (0D) metal halide hybrids L2ZnBr4 [1, L = (E)-4-(2-(1H-pyrrol-3-yl)vinyl)-1-methylpyridin-1-ium] and L6Pb3Br12 (2) were prepared, which demonstrated photochromism and photoinduced cracking. Upon irradiation at 450 nm, a single crystal-to-single crystal transformation occurred as a result of the [2 + 2] photocycloaddition of L. Interestingly, compared to the complete photocycloaddition of L in 1, only two-thirds of L monomers could be photodimerized in 2 because of the difference in L orientation. 1 shows reversible photochromic behavior including rapid response time, few cracks, high conversion rate, and good reaction reversibility, while 2 exhibits no significant color change but distinct photoinduced cracking because of the large local lattice strain induced by inhomogeneous and anisotropic deformation. Moreover, the photocycloaddition of L results in the distinct shift of photoluminescence of 1 and 2, attributed to the variation in conjugation of π electrons and distortion of metal halide clusters. As a proof-of-concept, reversible optical writing is demonstrated for 1. These findings provide new insights into the design of stimuli-responsive multifunctional materials.

Efficacy and safety of total glucosides of paeony in treating primary Sjögren's syndrome: a propensity-matched study.

OBJECTIVE: This study aimed to evaluate the efficacy and safety of total glucosides of paeony (TGP) in patients with primary Sjögren's syndrome (pSS). PATIENTS AND METHODS: This study included 236 patients with pSS, including 118 TGP users and 118 non-users. Propensity score matching and Binary logistic regression analyses were used to minimize confounding factors and determine the association between TGP treatment and clinical variables. RESULTS: The baseline indexes of TGP users and non-users were basically the same. The median time of follow-up in the two groups was also similar (p < 0.05). Compared with non-users, TGP users showed higher rates of improvement in dry mouth and eyes and musculoskeletal involvement, as well as more significant reductions in serum alanine aminotransferase (ALT) and direct bilirubin (DBIL) levels after treatment. Logistic regression confirmed that the use of TGP was negatively correlated with the increase of ALT and DBIL in pSS patients, and the reduction in these variables was more pronounced after 2 years of treatment. The incidence of adverse reactions in the TGP users was 11.9%, which was compatible with those in non-users. CONCLUSIONS: TGP is often a safe option for treating pSS patients with musculoskeletal features and abnormal ALT levels. Besides, it can help improve dry mouth and dry eyes and decrease DBIL levels.

[A survey on the implementation of cardiovascular surgery for congenital heart disease in China between 2017 and 2021].

Objective: To investigate the inplementation of cardiovascular surgery for congenital heart disease (CHD) in China. Methods: A cross-sectional study was carried out. The CHD cardiovascular surgery data collected by the Chinese Society of Extracorporeal Circulation from 2017 to 2021 in 31 provinces (autonomous regions/municipalities) of China were retrospectively reviewed, the implementation of CHD cardiovascular surgery in different provinces, regions, general/specialized hospitals, and different age groups (whether≤18 years old) were summarized, and the correlation analysis between the number of surgeries carried out in each province/region and the gross regional product and the number of the regional population was performed. Results: Between 2017 and 2021, the annual volume of CHD cardiovascular surgery was 77 120, 77 634, 81 161, 62 663 and 71 492, respectively, showing a decreasing trend. Meanwhile, the proportion of CHD patients aged≤18 years who underwent cardiovascular surgery also showed a downward trend, from 79.8% (61 557/77 120) in 2017 to 58.6% (41 871/71 492) in 2021 (P=0.027). The number of surgical cases varied greatly among different provinces, including 4 provinces with≥5 000 cases and 9 provinces with 2 000-5 000 cases. In the five years, the number of CHD cardiovascular surgeries in Central and East China was the largest, accounting for 41.1%-45.5% of the total surgical cases. The proportion of CHD surgery cases≤18 years old was the highest in Southwest China (69.7%-87.4%) and the lowest in Northeast China (28.2%-68.9%). Except for 2021, the number of cases carried out by each region between 2017 and 2020 was correlated with the gross regional product (r=0.929, 0.929, 0.893 and 0.964, respectively, all P<0.05) and the population (r=0.821, 0.893, 0.821 and 0.857, respectively, all P<0.05). Hospitals that performed more than 100 operations (20.5%±1.2% of the total number of hospitals) completed 86.2%±1.2% of the total number of operations in China during the 5-year period. In 2017 and 2021, the number of CHD cardiovascular surgeries preformed in children's/women's and children's specialized hospitals accounted for 24.3% (18 772/77 120) and 23.8% (17 012/71 492) of the total number of cases in China, respectively. Conclusions: From 2017 to 2021, the number of cardiovascular surgery for CHD decreases slightly, but the proportion of surgery for adult CHD patients increases significantly.There is a strong correlation between the number of CHD operations in each region and their economic development status. The scale of CHD cardiovascular surgery performed in children's hospitals/women's and children's hospitals accounts for about a quarter of the total volume in China.

Ultrafast Exciton Dynamics of CH3NH3PbBr3 Perovskite Nanoclusters.

Exciton dynamics of perovskite nanoclusters has been investigated for the first time using femtosecond transient absorption (TA) and time-resolved photoluminescence (TRPL) spectroscopy. The TA results show two photoinduced absorption signals at 420 and 461 nm and a photoinduced bleach (PB) signal at 448 nm. The analysis of the PB recovery kinetic decay and kinetic model uncovered multiple processes contributing to electron-hole recombination. The fast component (∼8 ps) is attributed to vibrational relaxation within the initial excited state, and the medium component (∼60 ps) is attributed to shallow carrier trapping. The slow component is attributed to deep carrier trapping from the initial conduction band edge (∼666 ps) and the shallow trap state (∼40 ps). The TRPL reveals longer time dynamics, with modeled lifetimes of 6.6 and 93 ns attributed to recombination through the deep trap state and direct band edge recombination, respectively. The significant role of exciton trapping processes in the dynamics indicates that these highly confined nanoclusters have defect-rich surfaces.

Effect of Lattice Disorder on Exciton Dynamics in Copper-Doped InP/ZnSexS1-x Core/Shell Quantum Dots.

InP/ZnSexS1-x core/shell quantum dots (QDs) with varying Cu concentrations were synthesized by a one-pot hot-injection method. X-ray diffraction and high-resolution transmission electron microscopy results indicate that Cu doping did not alter the crystal structure or particle size of the QDs. The optical shifts in UV-visible absorption and photoluminescence (PL) suggest changes in the electronic structure and induction of lattice disorder due to Cu doping. Ultrafast transient absorption spectroscopy (TAS) reveled that a higher Cu-doping level leads to faster charge carrier recombination, likely due to increased nonradiative decay from defect states. Time-resolved PL (TRPL) studies show longer average lifetimes of charge carriers with increased Cu doping. These findings informed the development of a kinetic model to better understand how Cu-induced disorder affects charge carrier dynamics in the QDs, which is important for emerging applications of Cu-doped InP/ZnSexS1-x QDs in optoelectronics.

[The impact of augmented reality glasses on human visual efficiency and digital eye fatigue].

Objective: To investigate the differences in reading efficiency and visual fatigue between the use of augmented reality (AR) glasses and laptops. Methods: A prospective self-controlled study was conducted. Healthy students from Capital Medical University who frequently engaged in long-term near work and used laptops and other digital display devices were recruited as subjects at Beijing Tongren Hospital, Capital Medical University between November 1 and November 15, 2023. LogMAR visual acuity, visual functions (accommodation, convergence, and fusion), and visual fatigue scores (Likert visual fatigue scale) of the participants were assessed. The order of using the laptop and AR glasses for each participant was determined by a coin toss. Reading efficiency (reading speed and error rate multiplied by the detection rate of incorrect numbers) with different devices for 10 minutes at the same time on different dates and visual fatigue scores after watching a 20-minute video were measured. Statistical analyses were performed using paired t-tests and Wilcoxon signed-rank tests. Results: A total of 20 eligible subjects were included, comprising 7 males and 13 females, with a mean age of (25.45±2.27) years. There was no significant change in binocular visual acuity before and after using AR glasses and laptops (both P>0.05). The reading speed and reading efficiency of using AR glasses [(34.03±9.25) and (29.19±7.62) digits/min, respectively] were significantly lower than those of using laptops [(39.43±10.36) and (35.67±9.87) digits/min, respectively] (t=4.36, P<0.001), while the difference in error detection rate was not statistically significant (t=1.29, P=0.213). There was no statistically significant difference in visual fatigue scores before watching videos with the two devices (Z=-0.71, P=0.480). However, the visual fatigue score after watching videos with AR glasses [(20.55±5.04) points] was significantly higher than that with laptops [16.50 (13.00, 19.75) points] (Z=-2.85, P=0.004). The visual fatigue scores after watching videos with both devices were significantly higher than before (P<0.05), with a more significant increase observed with AR glasses [(6.05±3.50) points] (Z=-3.41, P<0.001). Conclusion: Compared with using laptops, the reading speed and efficiency were lower, and the visual fatigue was more pronounced with the use of AR glasses at the current technical level. Further optimization and improvement of AR glasses are warranted.

[New progress in the first-line treatment of advanced hepatocellular carcinoma].

Hepatocellular carcinoma is a kind of cancer with a strong invasion, a high incidence rate and mortality, and a poor prognosis. At the time of diagnosis, most patients are already in the advanced stages of a tumor and have lost the chance for radical surgical treatment. Advanced hepatocellular carcinoma treatment has a gradual transition from systemic chemotherapy to targeted therapy, immunotherapy, and combination therapy, especially immune checkpoint inhibitor-based immunotherapy combination therapy, such as combination with bevacizumab monoclonal antibodies and other drugs, or combination with TACE, HAIC, radiotherapy, ablation, and other treatment methods. Combination therapy has significant synergistic effects and thus has already become a future treatment trend for hepatocellular carcinoma. An immunotherapy-based combination therapy plan will run through the whole process of systemic therapy, which is expected to bring better survival benefits to patients with hepatocellular carcinoma. This article reviews the latest research progress in aspects of the first-line treatment of advanced hepatocellular carcinoma.

Photocatalytic CO2 Reduction Coupled with Oxidation of Benzyl Alcohol over CsPbBr3@PANI Nanocomposites.

Herein, we successfully prepare conductive polyaniline (PANI)-encapsulated CsPbBr3 perovskite nanocrystals (PNCs) that demonstrate much improved photocatalytic performance and stability toward the CO2 reduction reaction (CRR) coupled with oxidation of benzyl alcohol (BA) to benzaldehyde. Due to the acid-base interaction between CO2 and PANI, CO2 molecules are selectively adsorbed on PANI in the form of carbamate. As a result, the rate of production of CO (rCO) reaches 26.1 µmol g-1 h-1 with a selectivity of 98.1%, which is in good agreement with the rate of oxidation (∼27.0 µmol g-1 h-1) of BA. Such a high reduction/oxidation rate is enabled by the fast electron transfer (∼2.2 ps) from PNCs to PANI, as revealed by femtosecond transient absorption spectroscopy. Moreover, because of the benefit of the encapsulation of PANI, no significant decrease in rCO is observed in a 10 h CRR test. This work offers insight into how to simultaneously achieve improved photocatalytic performance and stability of CsPbX3 PNCs.

[Technical specification for orthodontic transmission straight wire technique].

Malocclusion is an oral disease with a high prevalence. The goal of orthodontic treatment is health, aesthetics, function and stability. The transmission straight wire appliance and technique is an innovative orthodontic system with independent intellectual property rights invented by Professor Jiuxiang Lin's team based on decades of clinical experience, which provides a new solution for the non-surgical correction of skeletal malocclusions, especially class Ⅲ malocclusion, and it is also a good carrier for the implementation of the concept of healthy orthodontics. Due to the lack of guidelines, how to implement standardized application of transmission straight wire technique remains a problem to be solved. This technical specification was formed by combining the guidance from Professor Jiuxiang Lin and joint revision by a number of authoritative experts from the Orthodontic Special Committee, Chinese Stomatological Association, with reference to relevant literatures, and combined with abundant clinical experience of many experts. This specification aims to provide reference to standardize the clinical application of transmission straight wire technique, so as to reduce the risk and complications, and finally to improve the clinical application level of this technique.

[Clinical efficacy of antibiotic bone cement combined with vacuum sealing drainage in treating diabetes mellitus complicated with necrotizing fasciitis].

Objective: To explore the clinical efficacy of antibiotic bone cement combined with vacuum sealing drainage (VSD) in treating diabetes mellitus complicated with necrotizing fasciitis. Methods: The retrospective observational study approach was used. From January 2020 to March 2022, 12 patients with type 2 diabetes complicated with necrotizing fasciitis who met the inclusion criteria were admitted to Wuxi Ninth People's Hospital, including 7 males and 5 females, aged 27 to 76 years. The initial diagnosis of lesions was in the lower limbs. After admission, bedside incision and drainage were performed timely, and a sample of wound exudate was collected for microbial cultivation. At the same time, the comprehensive supportive treatment was performed. At stage Ⅰ, debridement was performed, and the skin and soft tissue defect area was 40 cm×15 cm to 80 cm×25 cm after debridement. The dead space was filled with bone cement containing gentamicin and vancomycin and VSD was performed. After there was no obvious infection on the wound, the antibiotic bone cement was removed and wound repair surgery was performed at stage Ⅱ. The times of debridement, amputation, infection control, wound treatment method and wound healing at stage Ⅱ, total hospitalization day, and recurrence of necrotizing fasciitis during follow-up after the stage Ⅱ surgery. At the last follow-up, the walking function of patients was evaluated according to the scoring standards of American Orthopedic Foot and Ankle Association (AOFAS). Results: Eleven patients had wound infection control with one debridement surgery and did not undergo amputation surgery; one patient had significant foot gangrene, and the infection was controlled after one debridement and amputation of the gangrenous limb. Blood routine and infection indicators gradually returned to normal within 7 days after surgery. At stage Ⅱ, the wounds in 4 patients were sutured directly, the wounds in 6 patients were repaired with full-thickness inguinal skin graft, while the wounds in 2 patients were repaired with pedicled or tongue-shaped flaps at the wound edge. The wounds healed well after surgery, with no ulceration. The total hospitalization day of patients was 20 to 45 days. Follow-up for 3 to 24 months after stage Ⅱ surgery showed no recurrence of necrotizing fasciitis in any patient. At the last follow-up, the walking function was evaluated as excellent in 10 cases and good in 2 cases according to the AOFAS scoring standard. Conclusions: Antibiotic bone cement combined with VSD used in treating type 2 diabetes complicated with necrotizing fasciitis can effectively control infection and reduce the times of debridement, with good wound healing and walking function after surgery.

Novel Chiral CsPbBr3 Metal Halide Perovskite Magic-Sized Clusters and Metal Halide Molecular Clusters with Achiral Ligands.

We have synthesized inherently chiral cesium lead halide perovskite magic-sized clusters (PMSCs) and ligand-assisted metal halide molecular clusters (MHMCs) using the achiral ligands octanoic acid (OCA) and octylamine (OCAm). UV-vis electronic absorption was used to confirm characteristic absorption bands while circular dichroism (CD) spectroscopy was utilized to determine their chiroptical activity in the 412-419 and 395-405 nm regions, respectively. In contrast, the larger sized counterpart of PMSCs, namely, perovskite quantum dots (PQDs), do not show chirality. The inherent chirality of the clusters is tentatively attributed to a twisted chiral layered structure, defect-induced chiral structure, or twisted Pb-Br octahedra.

Plasma position measurements by O-mode and X-mode reflectometry systems in tokamak plasmas.

Plasma Position Reflectometry (PPR) is planned to provide plasma position and shape information for plasma operation in future fusion reactors. Its primary function is to calibrate the drift of the magnetic signals due to the integral nature of magnetic measurement. Here, we attempt to measure plasma position using ordinary mode (O-mode) and extraordinary mode (X-mode) reflectometry systems on two tokamaks. A new physical model based on the phase shift is proposed to deduce the relative movement of the cut-off layer without density inversion. We demonstrate the plasma position measurements by absolute measurement from density profile inversion and relative measurement from phase shift. The combination of X-mode and O-mode reflectometers can minimize the limitations of single polarization reflectometry and further increase the accuracy of plasma position measurement. These results could provide an important technical basis for the further development of a real-time control system based on PPR.

[The necessity of the multidisciplinary comprehensive treatment of orthodontics].

The rapid development of orthodontics is based on the oral health. Healthy oral cavity includes teeth, alveolar bone, maxilla and mandible, periodontal tissue, dental body, temporomandibular joint and other structures, which should function with coordination, stability and esthetics. Based on the above requirements, the clinical treatment of orthodontics often needs multidisciplinary cooperation to obtain satisfactory results. This paper makes a review on the multidisciplinary collaborative treatment of orthodontics.

Ultrafast Study of Excited State Dynamics of Amino Metal Halide Molecular Clusters.

The excited state dynamics of ligand-passivated PbBr2 molecular clusters (MCs) in solution have been investigated for the first time using femtosecond transient absorption spectroscopy. The results uncover a transient bleach (TB) feature peaked around 404 nm, matching the ground state electronic absorption band peaked at 404 nm. The TB recovery signal can be fitted with a triple exponential with fast (10 ps), medium (350 ps), and long (1.8 ns) time constants. The medium and long time constants are very similar to those observed in the time-resolved photoluminescence (TRPL) decay monitored at 412 nm. The TB fast component is attributed to vibrational relaxation in the excited electronic state while the medium component with dominant amplitude is attributed to recombination between the relaxed electron and hole. The small amplitude slow component is assigned to electrons in a relatively long-lived excited electronic state, e.g., triplet state, or shallow trap state due to defects. This study provides new insights into the excited state dynamics of metal halide MCs.