[Strolling through the glorious years of Alveolar Surgery, bravely stepping onto the path of practice and innovation]

This article summarizes and organizes relevant publications in journals, along with a review of medical history, systematically summarizing the development process of dental alveolar surgery in China. The initial establishment phase (1935-1952) marked the starting point of Chinese Alveolar Surgery. Despite the impact of wars, it laid the foundation for subsequent research and practice. During the early development phase (1953-1966), the "Chinese Journal of Stomatology" was founded, which promoted the development of Alveolar Surgery. Research focused on tooth extraction methods and complications. Tooth Transplantation and Preprosthetic Surgery gradually began to take off. The stagnant phase (1967-1977) occurred due to the interruption of international exchanges, leading to an almost complete halt in the development of Alveolar Surgery. Entering the rapid catch-up phase (1978-1985), Alveolar Surgery scholars in China began striving to overcome the stagnation of the previous decade. While some progress was made, no significant innovative achievements emerged. In the scientific development phase (1986-2010), clinical research, basic experiments, and paper writing in modern Chinese Alveolar Surgery began to adhere to scientific standards with the rise of experimental medicine. The exploration and innovation stage (2011-2023) is the current development phase, during which Chinese Aveolar Surgery has reached its peak, making substantial progress in technology, clinical practices, and basic research, gradually reaching or even surpassing international advanced levels. Looking back at the development history in China, we can find the wisdom and hard work of the older generation of Alveolar Surgery scholars. However, contemporary challenges and issues, such as standardizing technology, promoting clinical practices, and talent cultivation, need to be addressed by present-day Alveolar Surgery professionals as they forge ahead.

Influence of ligands on the optical properties of rod-shaped Au25 nanoclusters

In this study, we successfully synthesized rod-shaped [Au25(PPh3)10(S-Adm)5Cl2]2+ nanoclusters using kinetic controls. The complete molecular structure was determined by single-crystal X-ray crystallography and electrospray ionization mass spectrometry. In comparison with the previously reported [Au25(PPh3)10(PET)5Cl2]2+ clusters, both nanoclusters have an icosahedral composition of Au13 linked by Au atoms that share a vertex, but [Au25(PPh3)10(S-Adm)5Cl2]2+ clusters appear elongated due to the rigidity of adamantane. We conducted ultraviolet-visible spectrophotometry (UV-vis) measurements of [Au25(PPh3)10(PET)5Cl2]2+ and [Au25(PPh3)10(S-Adm)5Cl2]2+ in dichloromethane solvent to elucidate the modulation of the cluster properties of different ligands. The lowest energy absorption peak of [Au25(PPh3)10(S-Adm)5Cl2]2+ shifted to lower energies compared to the [Au25(PPh3)10(PET)5Cl2]2+ clusters in UV-vis measurements. Temperature-dependent absorption measurements revealed that [Au25(PPh3)10(S-Adm)5Cl2]2+ clusters were less affected by temperature compared to [Au25(PPh3)10(PET)5Cl2]2+. This result is attributed to the exciton phonon coupling of [Au25(PPh3)10(S-Adm)5Cl2]2+ clusters being weaker than [Au25(PPh3)10(PET)5Cl2]2+ clusters. Furthermore, the absorption spectra of [Au25(PPh3)10(PET)5Cl2]2+ and [Au25(PPh3)10(S-Adm)5Cl2]2+ clusters were measured using different types of solutions, and it was found that the lowest energy absorption peaks of [Au25(PPh3)10(S-Adm)5Cl2]2+ were shifted and affected by the solution at room temperature, which suggested that the [Au25(PPh3)10(S-Adm)5Cl2]2+ clusters with solution hydrogen bonds also interacted strongly at room temperature. Theoretical calculations show that changes in ligands affect the differences in the molecular orbitals and structures of the clusters, which cause changes in the optical properties.

Amorphous Metal-Organic Framework-Derived Electrocatalyst to Boost Water Oxidation

Amorphous metal-organic framework (MOF) materials have drawn extensive interest in the design of high-performance electrocatalysts for use in the electrochemical oxygen evolution reaction. However, there are limitations to the utilization of amorphous MOFs due to their low electrical conductivity and unsatisfactory stability. Herein, a novel amorphous-crystalline (AC) heterostructure is successfully constructed by synthesizing a crystalline metal sulfide (MS)-embedded amorphous Ni_0.67Fe_0.33-MOF, namely an MS/Ni_0.67Fe_0.33-MOF. It exhibits excellent catalytic performance (a low overpotential of 248 mV at 10 mA cm^-2 with a small Tafel slope of 50 mV decade^-1), durability, and stability (only 8% degradation of the current density at a constant voltage after 24 h). This work thus sheds light on the engineering of highly efficient catalysts with AC heterointerfaces for optimizing water-splitting systems.

Electrical devices designed based on inorganic clusters

The idea of exploring the bottom brink of material science has been carried out for more than two decades. Clusters science is the frontmost study of all nanoscale structures. Being an example of 0-dimensional quantum dot, nanocluster serves as the bridge between atomic and conventionally understood solid-state physics. The forming mechanism of clusters is found to be the mutual effects of electronic and geometric configuration. It is found that electronic shell structure influences the properties and geometric structure of the cluster until its size becomes larger, where electronic effects submerge in geometric structure. The discrete electronic structures depend on the size and conformation of clusters, which can be controlled artificially for potential device applications. Especially, small clusters with a size of 1-2 nm, whose electronic states are possibly discrete enough to overcome thermal fluctuations, are expected to build a single-electron transistor with room temperature operation. However, exciting as the progress may be seen, cluster science still falls within the territory of merely the extension of atomic and molecular science. Its production rate limits the scientific and potential application research of nanoclusters. It is suggested in this review that the mass-produce ability without losing the atomic precision selectivity would be the milestone for nanoclusters to advance to material science.

Enhanced Methanol Electro-Oxidation Activity of Nanoclustered Gold

Size-selected 3 nm gas-phase Au clusters dispersed by cluster beam deposition (CBD) on a conducting fluorine-doped tin oxide template show strong enhancement in mass activity for the methanol electro-oxidation (MEO) reaction compared to previously reported nanostructured gold electrodes. Density functional theory-based modeling on the corresponding Au clusters guided by experiments attributes this high MEO activity to the high density of exposed under-coordinated Au atoms at their faceted surface. In the description of the activity trends, vertices and edges are the most active sites due to their favorable CO and OH adsorption energies. The faceted structures occurring in this size range, partly preserved upon deposition, may also prevent destructive restructuring during the oxidation-reduction cycle. These results highlight the benefits of using CBD in fine-tuning material properties on the nanoscale and designing high-performance fuel cell electrodes with less material usage.

[Effects of interpregnancy interval on pregnancy outcomes of subsequent pregnancy: a multicenter retrospective study]

Objective: To explore the effects of interpregnancy interval (IPI) on pregnancy outcomes of subsequent pregnancy. Methods: A multicenter retrospective study was conducted in 21 hospitals in China. Information of age, height, pre-pregnancy weight, IPI, history of diseases, complications of pregnancy, gestational age of delivery, delivery mode, and pregnancy outcomes of the participants were collected by consulting medical records of pregnant women who had two consecutive deliveries in the same hospital during 2011 to 2018. The participants were divided into 4 groups according to IPI:<18 months, 18-23 months, 24-59 months and ≥60 months. According to the WHO's recommendation, with the IPI of 24-59 months group as a reference, to the effects of IPI on pregnancy outcomes of subsequent pregnancy were analyzed. Stratified analysis was further carried out based on age, history of gestational diabetes mellitus (GDM), macrosomia, and premature delivery, to explore the differences in the effects of IPI on pregnancy outcomes among women with different characteristics. Results: A total of 8 026 women were included in this study. There were 423, 623, 5 512 and 1 468 participants in <18 months group, 18-23 months group, 24-59 months group and ≥60 months group, respectively. (1) The age, pre-pregnancy body mass index (BMI), history of cesarean section, GDM, gestational hypertension and cesarean section delivery rate of <18 months group, 18-23 months group, 24-59 months group and ≥60 months group were gradually increased, and the differences were statistically significant (P<0.05). (2) After adjusting for potential confounding factors, compared with women in the IPI of 24-59 months group, the risk of premature delivery, premature rupture of membranes, and oligohydramnios were increased by 42% (OR=1.42, 95%CI: 1.07-1.88, P=0.015), 46% (OR=1.46, 95%CI: 1.13-1.88, P=0.004), and 64% (OR=1.64, 95%CI: 1.13-2.38, P=0.009) respectively for women in the IPI≥60 months group. No effects of IPI on other pregnancy outcomes were found in this study (P>0.05). (3) After stratified by age and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would significantly increase the risk of oligohydramnios for women with advanced age (OR=2.87, 95%CI: 1.41-5.83, P=0.004); and <18 months could increase the risk of premature rupture of membranes for women under the age of 35 (OR=1.59, 95%CI: 1.04-2.43, P=0.032). Both the risk of premature rupture of membranes (OR=1.58, 95%CI: 1.18-2.13, P=0.002) and premature delivery (OR=1.52, 95%CI: 1.07-2.17, P=0.020) were significantly increased in the IPI≥60 months group. After stratified by history of GDM and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would lead to an increased risk of postpartum hemorrhage for women with a history of GDM (OR=5.34, 95%CI: 1.45-19.70, P=0.012) and an increased risk of premature rupture of membranes for women without a history of GDM (OR=1.44, 95%CI: 1.10-1.90, P=0.009). After stratified by history of macrosomia and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months could increase the proportion of cesarean section for women with a history of macrosomia (OR=4.11, 95%CI: 1.18-14.27, P=0.026) and the risk of premature rupture of membranes for women without a history of macrosomia (OR=1.46, 95%CI: 1.12-1.89, P=0.005). After stratified by history of premature delivery and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would significantly increase the risk of premature rupture of membranes for women without a history of premature delivery (OR=1.47, 95%CI: 1.13-1.92, P=0.004). Conclusions: Both IPI≥60 months and <18 months would increase the risk of adverse pregnancy outcomes in the subsequent pregnancy. Healthcare education and consultation should be conducted for women of reproductive age to maintain an appropriate IPI when they plan to pregnant again, to reduce the risk of adverse pregnancy outcomes in the subsequent pregnancy.

[Expert consensus on the treatment of oral and maxillofacial space infections]

Oral and maxillofacial space infections (OMSI) are common diseases of the facial region involving fascial spaces. Recently, OMSI shows trends of multi drug-resistance, severe symptoms, and increased mortality. OMSI treatment principles need to be updated to improve the cure rate. Based on the clinical experiences of Chinese experts and with the incorporation of international counterparts' expertise, the principles of preoperative checklist, interpretation of examination results, empirical medication principles, surgical treatment principles, postoperative drainage principles, prevention strategies of wisdom teeth pericoronitis-related OMSI, blood glucose management, physiotherapy principles, Ludwig's angina treatment and perioperative care were systematically summarized and an expert consensus on the diagnosis and treatment of OMSI was reached. The consensus aims to provide criteria for the diagnosis and treatment of OMSI in China so as to improve the level of OMSI treatment.

A Gd@C82 single-molecule electret

Electrets are dielectric materials that have a quasi-permanent dipole polarization. A single-molecule electret is a long-sought-after nanoscale component because it can lead to miniaturized non-volatile memory storage devices. The signature of a single-molecule electret is the switching between two electric dipole states by an external electric field. The existence of these electrets has remained controversial because of the poor electric dipole stability in single molecules. Here we report the observation of a gate-controlled switching between two electronic states in Gd@C₈₂. The encapsulated Gd atom forms a charged centre that sets up two single-electron transport channels. A gate voltage of ±11 V (corresponding to a coercive field of ~50 mV Å^-1) switches the system between the two transport channels with a ferroelectricity-like hysteresis loop. Using density functional theory, we assign the two states to two different permanent electrical dipole orientations generated from the Gd atom being trapped at two different sites inside the C₈₂ cage. The two dipole states are separated by a transition energy barrier of 11 meV. The conductance switching is then attributed to the electric-field-driven reorientation of the individual dipole, as the coercive field provides the necessary energy to overcome the transition barrier.

[Anatomical study of rat trigeminal motor nucleus-lateral pterygoid muscle projection pathway]

Objective: To determine the opening and closing action of the external muscle, the projection pathway of the axon terminal of trigeminal motor nucleus (Vmo) neuron to the lateral pterygoid muscle was revealed. Methods: In this study, 10 SD rats of 8 weeks old were included. The left lateral pterygoid muscle of SD rats was surgically exposed, and the wound was closed after intramuscular injection of hydroxystilbamidine/fluorogold (FG) 3-5 μl. Seven days after the operation, the experimental animals were perfused, samples collected and sectioned for immunofluorescence staining. After FG injection into the lateral pterygoid muscle, the FG reversed in the Vmo neurons. Results: In the Vmo neurons on the FG injection side (left side), a large number of FG reversed neurons were found in the corpus luteum and dendrites. These neurons were not only distributed in the dorsolateral part of the trigeminal motor nucleus that innervated the closed muscle, but also in the ventral medial portion of the trigeminal nucleus of the open muscle. Conclusions: The neuronal conduction pathway between the Vmo and the lateral pterygoid muscle innervates the lateral pterygoid muscle. The neurons are distributed both in the dorsolateral and in the nucleus of the ventral ventricle. It is concluded that the lateral pterygoid muscle involve in the jaw closing and opening movement.

A platinum-nickel bimetallic nanocluster ensemble-on-polyaniline nanofilm for enhanced electrocatalytic oxidation of dopamine

We report a new approach to design flexible functional material platforms based on electropolymerized polyaniline (PANI) polymer nanofilms modified with bimetallic nanoclusters (NCs) for efficient electro-oxidation of small organic molecules. Composition defined ligand free Pt_0.75Ni_0.25 NCs were synthesized in the gas phase using the Cluster Beam Deposition (CBD) technology and characterized using RToF, HAADF-STEM, XAFS and XPS. NCs were then directly deposited on PANI coated templates to construct electrodes. Dopamine (DP) molecules were used as a representative organic analyte and the influence of the NC-PANI hybrid atomistic structure on the electrochemical and electrocatalytic performance was investigated. The as prepared, nearly monodispersed, Pt_0.75Ni_0.25 NCs of ca. 2 nm diameter featuring a PtOx surface combined with a shallow platelet-like Ni-O(OH) phase formed a densely packed active surface on PANI at ultralow metal coverages. Electrochemical measurements (EIS and CV) show a 2.5 times decrease in charge transfer resistance and a remarkable 6-fold increase at lower potential in the mass activity for Pt_0.75Ni_0.25 NCs in comparison with their pure Pt counterparts. The enhanced electrochemical performance of the Pt_0.75Ni_0.25 NC hybrid's interface is ascribed to the formation of mixed Pt metal and Ni-O(OH) phases at the surface of the alloyed PtNi cores of the bimetallic NCs under electrochemical conditions combined with an efficient charge conduction pathway between NCs.

Unravelling the nucleation mechanism of bimetallic nanoparticles with composition-tunable core-shell arrangement

The structure and atomic ordering of Au-Ag nanoparticles grown in the gas phase are determined by a combination of HAADF-STEM, XPS and Refl-XAFS techniques as a function of composition. It is shown consistently from all the techniques that an inversion of chemical ordering takes place by going from Au-rich to Ag-rich compositions, with the minority element always occupying the nanoparticle core, and the majority element enriching the shell. With the aid of DFT calculations, this composition-tunable chemical arrangement is rationalized in terms of a four-step growth process in which the very first stage of cluster nucleation plays a crucial role. The four-step growth mechanism is based on mechanisms of a general character, likely to be applicable to a variety of binary systems besides Au-Ag.

[A retrospective analysis on the pernicious placenta previa from 2008 to 2014]

OBJECTIVE

To investigate the incidence changes, clinical characteristics and pregnant outcomes of pernicious placenta previa.

METHODS

A retrospective cohort analysis on 316 cases with placenta previa in the Peking University First Hospital from January 2008 to December 2014. The research group were 60 cases with the patients of placenta previa with the history of cesarean section, and the control group were placenta previa without the history of cesarean section. Compared with the incidence, intraoperative blood loss, the pregnancy outcomes and so on.

RESULTS

(1) The average incidence rate of placenta previa during the past 7 years was 10.96 ‰ (316/28 837). And the cases of pernicious placenta previa was 60 (2.08‰, 60/28 837), the incidence of pernicious placenta previa was rising from 2008 to 2014 (0.91‰-3.08‰). (2) There were 145 cases of placenta privia had been translation from other hospitals in the past 7 years. The referral rate of pregnant women with placenta previa was 45.9% (145/316), and the referral rate of pernicious placenta previa (63.3%, 38/60) was significantly higher than that of non-pernicious placenta previa group (41.8%, 107/256; χ(2)=9.080, P=0.003). Referral the outcomes of these patients were good, and no maternal death occurred. (3) The placenta in the research group were mainly adhered in the front wall of the uterine, and the incidence was 38.5% (15/39), higher than that in the group of non-pernicious placenta previa (12.1%, 21/174; χ(2)=57.636, P<0.01). The incidence rate of complicated placenta increased in research group was 53.3% (32/60), higher than that in the group of non-pernicious placenta previa, compared with the control group, there was significant difference (15.6%, 40/256; χ(2)= 39.041, P<0.01). (4) The incidence of blood loss was more than 1 000 ml, blood transfusion rate, the rate of hysterectomy and the rate of asphyxia of newborn in the research group were respectively 41.7% (25/60), 38.3% (23/60), 8.3% (5/60), 15.0% (9/60), and the incidence of the group of non-pernicious placenta previa were respectively 4.7% (12/256), 12.9% (33/256), 1.2% (3/256), 8.6% (22/256), compared those in other two groups, there were not significant difference (P<0.05).

CONCLUSIONS

The incidence rate of placenta previa increased year by year, patients with placenta previa has a history of cesarean section often combined with placenta in anterior wall of the uterus, and often with poor pregnancy outcomes. Hierarchical referral system is an effective means to reduce the mortality of the pernicious placenta previa.

Hybrid atomic structure of the Schmid cluster Au55(PPh3)12Cl6 resolved by aberration-corrected STEM

We have investigated the atomic structure of the Au55(PPh3)12Cl6 Schmid cluster by using aberration-corrected scanning transmission electron microscopy (STEM) combined with multislice simulation of STEM images. Atom counting was employed, with size-selected clusters as mass standards, to "fractionate" the correct cluster size in the image analysis. Systematic structure analysis shows that a hybrid structure, predicted by density functional theory, best matches nearly half the clusters observed. Most other clusters are amorphous. We believe our conclusions are consistent with all the previous, apparently contradictory structural studies of the Schmid cluster.