M2 macrophages secrete glutamate-containing extracellular vesicles to alleviate osteoporosis by reshaping osteoclast precursor fate.

Osteoclast precursors (OCPs) are thought to commit to osteoclast differentiation, which is accelerated by aging-related chronic inflammation, thereby leading to osteoporosis. However, whether the fate of OCPs can be reshaped to transition into other cell lineages is unknown. Here, we showed that M2 macrophage-derived extracellular vesicles (M2-EVs) could reprogram OCPs to downregulate osteoclast-specific gene expression and convert OCPs to M2 macrophage-like lineage cells, which reshaped the fate of OCPs by delivering the molecular metabolite glutamate. Upon delivery of glutamate, glutamine metabolism in OCPs was markedly enhanced, resulting in the increased production of α-ketoglutarate (αKG), which participates in Jmjd3-dependent epigenetic reprogramming, causing M2-like macrophage differentiation. Thus, we revealed a novel transformation of OCPs into M2-like macrophages via M2-EVs-initiated metabolic reprogramming and epigenetic modification. Our findings suggest that M2-EVs can reestablish the balance between osteoclasts and M2 macrophages, alleviate the symptoms of bone loss, and constitute a new approach for bone-targeted therapy to treat osteoporosis.

A Spatiotemporal Controllable Biomimetic Skin for Accelerating Wound Repair.

Skin injury repair is a dynamic process involving a series of interactions over time and space. Linking human physiological processes with materials' changes poses a significant challenge. To match the wound healing process, a spatiotemporal controllable biomimetic skin is developed, which comprises a three-dimensional (3D) printed membrane as the epidermis, a cell-containing hydrogel as the dermis, and a cytokine-laden hydrogel as the hypodermis. In the initial stage of the biomimetic skin repair wound, the membrane frame aids wound closure through pre-tension, while cells proliferate within the hydrogel. Next, as the frame disintegrates over time, cells released from the hydrogel migrate along the residual membrane. Throughout the process, continuous cytokines release from the hypodermis hydrogel ensures comprehensive nourishment. The findings reveal that in the rat full-thickness skin defect model, the biomimetic skin demonstrated a wound closure rate eight times higher than the blank group, and double the collagen content, particularly in the early repair process. Consequently, it is reasonable to infer that this biomimetic skin holds promising potential to accelerate wound closure and repair. This biomimetic skin with mechanobiological effects and spatiotemporal regulation emerges as a promising option for tissue regeneration engineering.

A Cyclical Magneto-Responsive Massage Dressing for Wound Healing.

Tissue development is mediated by a combination of mechanical and biological signals. Currently, there are many reports on biological signals regulating repair. However, insufficient attention is paid to the process of mechanical regulation, especially the active mechanical regulation in vivo, which has not been realized. Herein, a novel dynamically regulated repair system for both in vitro and in vivo applications is developed, which utilizes magnetic nanoparticles as non-contact actuators to activate hydrogels. The magnetic hydrogel can be periodically activated and deformed to different amplitudes by a dynamic magnetic system. An in vitro skin model is used to explore the impact of different dynamic stimuli on cellular mechano-transduction signal activation and cell differentiation. Specifically, the effect of mechanical stimulation on the phenotypic transition of fibroblasts to myofibroblasts is investigated. Furthermore, in vivo results verify that dynamic massage can simulate and enhance the traction effect in skin defects, thereby accelerating the wound healing process by promoting re-epithelialization and mediating dermal contraction.

Roles of SP/KLF transcription factors in odontoblast differentiation: From development to diseases.

OBJECTIVES: A zinc-finger transcription factor family comprising specificity proteins (SPs) and Krüppel-like factor proteins (KLFs) plays an important role in dentin development and regeneration. However, a systematic regulatory network involving SPs/KLFs in odontoblast differentiation has not yet been described. This review examined the expression patterns of SP/KLF gene family members and their current known functions and mechanisms in odontoblast differentiation, and discussed prospective research directions for further exploration of mechanisms involving the SP/KLF gene family in dentin development. MATERIALS AND METHODS: Relevant literature on SP/KLF gene family members and dentin development was acquired from PubMed and Web of Science. RESULTS: We discuss the expression patterns, functions, and related mechanisms of eight members of the SP/KLF gene family in dentin development and genetic disorders with dental problems. We also summarize current knowledge about their complementary or synergistic actions. Finally, we propose future research directions for investigating the mechanisms of dentin development. CONCLUSIONS: The SP/KLF gene family plays a vital role in tooth development. Studying the complex complementary or synergistic interactions between SPs/KLFs is helpful for understanding the process of odontoblast differentiation. Applications of single-cell and spatial multi-omics may provide a more complete investigation of the mechanism involved in dentin development.

A prospective, randomized, single-blinded study comparing the efficacy and safety of dexmedetomidine and propofol for sedation during endoscopic retrograde cholangiopancreatography.

BACKGROUND: Balanced propofol sedation is extensively used in endoscopic retrograde cholangiopancreatography (ERCP), but sedation-related adverse events (SRAEs) are common. In various clinical settings, the combination of dexmedetomidine with opioids and benzodiazepines has provided effective sedation with increased safety. The aim of this investigation was to compare the efficacy and safety of dexmedetomidine and propofol for sedation during ERCP. METHODS: Forty-one patients were randomly divided into two groups: the dexmedetomidine (DEX) group and the propofol (PRO) group. Patients in the DEX group received an additional bolus of 0.6 µg kg-1 dexmedetomidine followed by a dexmedetomidine infusion at 1.2 µg kg-1 h-1, whereas the PRO group received 1-2 mg kg-1 of propofol bolus followed by a propofol infusion at 2-3 mg kg-1 h-1. During ERCP, the primary outcome was the incidence of hypoxemia (SpO2 < 90% for > 10 s). Other intraoperative adverse events were also recorded as secondary outcomes, including respiratory depression (respiratory rate of < 10 bpm min-1), hypotension (MAP < 65 mmHg), and bradycardia (HR < 45 beats min-1). RESULTS: The incidence of hypoxemia was significantly reduced in the DEX group compared to the PRO group (0% versus 28.6%, respectively; P = 0.032). Patients in the PRO group exhibited respiratory depression more frequently than patients in the DEX group (35% versus 81%, respectively; P = 0.003). There were no significant differences in terms of hypotension and bradycardia episodes between groups. During the procedures, the satisfaction scores of endoscopists and patients, as well as the pain and procedure memory scores of patients were comparable between groups. CONCLUSION: In comparison with propofol, dexmedetomidine provided adequate sedation safety with no adverse effects on sedation efficacy during ERCP. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2200061468, 25/06/2022.

A novel simplified approach for endodontic retrograde surgery in short single-rooted teeth.

BACKGROUND: High technical thresholds, long operative times, and the need for expensive and specialized equipment impede the widespread adoption of endodontic microsurgery in many developing countries. This study aimed to compare the effects of a simplified, cost-effective, and time-efficient surgical approach involving orthograde obturation using biological ceramic material greater than 6 mm combined with apicoectomy for single-rooted teeth with short lengths with those of the conventional and current standard methods. MATERIALS AND METHODS: Forty-five premolars equally categorized into three groups: conventional surgery group, standard surgery group, and modified surgery group. A µCT scan was used to calculate the volume of voids. A micro-leakage test and scanning electron microscope (SEM) were performed to assess the sealing effect. Additionally, four cases of chronic periapical periodontitis in the anterior region were selected, and the patients received either the modified approach or the standard surgery for endodontic microsurgery. RESULTS: The volumes of voids in the apical 0-3 mm of the modified group and the standard group were comparable. The micro-leakage test and SEM examination demonstrated closely bonded fillings in the dentinal walls in both the modified surgery group and standard surgery group. The outcomes of the preliminary application of this modified procedure on patients were successful at the time of the follow-up cutoff. CONCLUSIONS: The modified surgery group exhibited similar root canal filling and apical sealing abilities with the standard procedure for single-rooted teeth with short lengths (< 20 mm). The preliminary application of this modified surgical procedure achieved favorable results.

Structural Transformation and Photoluminescent Property of Manganese-Doped Bismuth-Based Perovskites.

Here, we synthesized pure Cs3Bi2Cl9 (CBC) and manganese (Mn)-doped crystals with different feeding ratios, leading to changes in structure and luminescence. The crystals Cs3Bi2Cl9-Mn (CBCM) formed by doping a minor amount of Mn2+ (Bi/Mn = 8:1) maintain the orthorhombic phase structure of the host, but when Bi/Mn = 2:1, the crystal structure is more inclined to form Cs4MnBi2Cl12 (CMBC) of a trigonal phase. Combined with density functional theory (DFT) calculation, the results demonstrate that a moderate amount of Mn2+ doping can create impurity energy levels in the forbidden band. However, as the structure transitions, the type of energy band structure changes from indirect to direct, with completely different electronic orbital features. Temperature-dependent time-resolved and steady-state photoluminescence spectroscopies are used to explore the structure-related thermal properties and transitional process. Differences energy transfer routes are revealed, with CBCM relying on intersystem energy transfer and CMBC mainly depending on direct excitation of Mn2+ to produce d-d transitions. Furthermore, since CMBC is temperature-sensitive, we perform the first photoluminescent (PL) lifetime temperature measurement using CBMC and obtain a maximum relative sensitivity of 1.7 %K-1 and an absolute sensitivity of 0.0099 K-1. Our work provides insight into the mechanism of Mn2+ doping-induced luminescence and offers a potentially effective doping strategy for improving the PL properties of lead-free metal halide perovskites.

Coagulation after paediatric miniaturised versus conventional cardiopulmonary bypass: Retrospective cohort study.

BACKGROUND: Cardiopulmonary bypass (CPB) causes coagulation disorders after surgery. This study aimed to compare the coagulation parameters after congenital cardiac surgery with miniaturised CPB (MCPB) versus conventional CPB (CCPB). METHODS: We gathered information about children who underwent cardiac surgery between 1/1/2016 and 12/31/2019. Using propensity score-matched data, we compared the coagulation parameters and postoperative outcomes of the MCPB and CCPB groups. RESULTS: A total of 496 patients (327 with MCPB, 169 withCCPB) underwent congenital cardiac surgery, and 160 matched pairs in each group were enrolled in the analysis. Compared with CCPB children, MCPB children had a lowermean prothrombin time (14.9 ± 2.0 vs 16.4 ± 4.1; p < 0.001)and international normalised ratio (1.3 ± 0.2 vs. 1.4 ± 0.3; p < 0.001), but higher thrombin time (23.4 ± 20.4 vs 18.2 ± 4.4; p = 0.002). The CCPB group had greaterperioperative changes inprothrombin time, international normalised ratio, fibrinogen, and antithrombin III activity (all p < 0.01) but lower perioperative changesin thrombin time (p = 0.001) thanthe MCPB group. Ultra-fasttrack extubation and blood transfusionrates, postoperative blood loss, and intensive care unitlength of stay were considerably decreased in the MCPB group. There were no considerable intergroup differences in the activated partial thromboplastin time or platelet count. CONCLUSIONS: Compared with CCPB, MCPB was associated with lower coagulation changes and better early outcomes, including shorter intensive care unit stay and less postoperative blood loss.

Size effect on nonlinear optical properties and ultrafast dynamics of silver nanoparticles.

Z-scan technology was used to study the nonlinear absorption (NLA) and nonlinear refraction (NLR) of silver nanoparticles (Ag NPs) with various sizes under different laser intensities. The results demonstrate that the NLA and NLR of Ag NPs were size-dependent. Specifically, the 10 nm Ag NPs exhibit saturation absorption (SA) and insignificant NLR. The 20 and 40 nm Ag NPs show the coexistence of SA and reverse saturation absorption (RSA). SA is believed to result from ground-state plasma bleaching, whereas RSA originates from excited state absorption (ESA). The 20 nm and 40 nm Ag NPs shows increasing self-defocusing with the increase of laser intensity. It was observed that the energy relaxation of Ag NPs mainly includes two processes of electron-phonon and phonon-phonon couplings on the order of picoseconds.

Laser-induced crystal growth observed in CsPbBr3 perovskite nanoplatelets.

Benefiting from the easily adjustable optical properties of perovskite, CsPbBr3 nanocrystals (NCs) are considered to show their advantages in the field of display. Here, we report that a selective laser irradiation is used to induce CsPbBr3 nanostructural reshaping and then yielding a morphological change. Under 360 or 405 nm laser irradiation, a hierarchical crystal growth process occurs for the fabricated CsPbBr3 nanoplatelets (NPLs), which are first arranged in a side-by-side manner and reshaped into nanorods (NRs), and then NRs are arranged in the face-to-face manner to reshape into NCs. The entire process is monitored optically and microscopically, which showed that crystal growth relies on seeking a dynamic balance between heat dissipation and accumulation under laser irradiation. The heat on NPLs generated by laser irradiation dissipated with a low dissipation rate and thus led to temperature rising and lattice breaking, which turned out to be the driving force for the crystal growth in CsPbBr3 NPLs. This feasible laser irradiation-assisted method provides for crystal growth a reliable and scalable route toward the preparation of perovskite functional materials.

Empathy alleviates the learning burnout of medical college students through enhancing resilience.

OBJECTIVE: The problem of learning burnout of medical students is becoming prominent, and empathy can play a good predictive role in learning burnout. The present study aimed to investigate the relationship between empathy and learning burnout, as well as the mediation effect of resilience in this relation. METHODS: Five hundred and eighty-eighth college students from a key medical university in Yunnan Province was investigated using the Basic Empathy Scale, Learning Burnout Scale, and Connor-Davidson Resilience Scale. All the measures showed good reliability and validity in the present study. Data were analyzed using SPSS 23.0 and Amos 22.0. RESULTS: Using structural equation modeling, we tested a conceptual model indicated that: (1) medical students' empathy negatively and significantly predicted learning burnout; (2) medical students' empathy positively predicts mental resilience; (3) resilience of medical students negatively predicts learning burnout; (4) resilience partially mediated the relationship between empathy and learning burnout of medical students, while also controlling for family socioeconomic status. CONCLUSION: These findings highlight the mediating role of resilience in the effect of empathy on learning burnout of medical college students. It may contribute to a better understanding of the effect of empathy. Moreover, it can also provide constructive suggestions for protecting and improve empathy and resilience of medical college students.

Psychological stress of medical staffs during outbreak of COVID-19 and adjustment strategy.

COVID-19 has a significant impact on public health and poses a challenge to medical staffs, especially to front-line medical staffs who are exposed to and in direct contact with patients. To understand the psychological stress status of medical staffs during the outbreak of COVID-19, random sample questionnaire survey was conducted among 2110 medical staffs and 2158 college students in all provinces of China through a questionnaire, which was compiled and completed through the Questionnaire Star platform relying on Wechat, QQ, and other social software. The differences in psychological stress status of different groups were compared through the analysis of the questionnaire. Results revealed that in all provinces of China, medical staffs scored significantly higher on all items of psychological stress than college students (P < .001). In Wuhan, medical staffs scored significantly higher than college students in all items of psychological stress (P < .001). While among medical staffs, the group in Wuhan area scored significantly higher than the group outside Wuhan on the following items: "Thought of being in danger," "The possibility of self-illness," "Worrying about family infection" (P < .05), "Poor sleep quality," "Needing psychological guidance," and "Worrying about being infected" (P < .01) in the Psychological Stress Questionnaire, but on the item "Confidence in the victory of the epidemic," the group in Wuhan area scored significantly lower than the group outside Wuhan (P < .05). The emotion, cognition, physical, and mental response of front-line medical staff showed obvious "exposure effect", which calls for a psychological crisis intervention strategy that can be helpful.

Nonlinear optical properties of InP/ZnS core-shell quantum dots.

The nonlinear optical properties of an InP/ZnS core-shell quantum dot toluene solution were investigated using a Z-scan and transient absorption technique with femtosecond pulses and nanosecond pulses at 532 nm wavelengths, respectively. The research results showed that InP/ZnS core-shell quantum dots exhibited saturated absorption under the excitation of femtosecond pulses, and the switch from saturated absorption to reverse saturated absorption was observed under the excitation of nanosecond pulses. The mechanism of the switch was attributed to excited-state absorption. Moreover, the nonlinear refraction was shown as self-focusing and self-defocusing under the excitation of femtosecond and nanosecond pulses, respectively, which were attributed to the Kerr effect of electrons and the thermal effect of InP/ZnS quantum dots, respectively. The investigations show that InP/ZnS core-shell quantum dots are good materials, and have many potential applications in optical and electrical fields.

Wavelength-dependent nonlinear absorption and ultrafast dynamics process of Au triangular nanoprisms.

The nonlinear absorption and ultrafast dynamics process of Au triangular nanoprisms were investigated by using broadband (ranging from 550 to 700 nm) nanosecond Z-scan measurements and femtosecond time-resolved transient absorption spectrum, respectively. We found that Au triangular nanoprisms exhibit saturation absorption (SA) at low excitation intensities. With the increase of incident intensity, a switch from SA to reverse saturation absorption (RSA) occurs. Photo-dynamics process was found to be a double-exponential energy relaxation with a fast and a slow decay component. Interestingly, when probe wavelength is away from the plasma resonance peak, the decay of relaxation also shows the modulation due to the vibration mode of the coherent excitation.

Ultrafast optical properties of type-II CdZnS/ZnSe core-shell quantum dots.

In this study, the ultrafast optical properties of type-II CdZnS/ZnSe core-shell quantum dots were investigated using the Z-scan and transient absorption technique with femtosecond pulses. With 800-nm wavelength excitation, the CdZnS/ZnSe quantum dots exhibited two-photon absorption, and the two-photon absorption cross section was obtained as about 3.37 × 106 GM. In addition, the transfer time of electrons and the recombination lifetime of a single exciton were obtained. For the photoluminescence of the CdZnS/ZnSe quantum dots at temperatures from 80 to 280 K, the peak position redshifted by 60 meV, width broadened by 3 meV, and intensity decreased by a factor of four.

Temperature and excitation wavelength-dependent photoluminescence of CH3NH3PbBr3 crystal.

We have investigated temperature and excitation wavelength-dependent luminescent properties of CH3NH3PbBr3 (MAPbBr3) perovskite crystal using steady-state and time-resolved photoluminescence (PL) spectroscopy. Optical spectroscopic results indicate that the PL intensity, peak wavelength, and full width at half maximum are jumped due to the phase transition from orthorhombic to tetragonal and cubic. As temperature increases, the peaks of above-bandgap and intrinsic PL have blueshift and redshift, respectively. The above-bandgap PL emerges under one-photon laser excitation and vanishes under the excitation of near-infrared femtosecond laser due to reabsorption. The initial redshift of PL peak and lifetime change at various wavelengths reveals the existence of a trap-assisted excitonic state. It is found that upconversion PL in all phases is composed of a photoinduced thermal-assisted and an intrinsic excitonic state, which produces the observation of biexponential dynamics. Our results can facilitate the understanding of the thermal effect of exciton recombination in hybrid perovskite crystal.

Ultrafast spectroscopic studies of composition-dependent near-infrared-emitting alloyed CdSeTe quantum dots.

In this study, optical and structural characterizations of near-infrared-emitting alloyed CdSeTe quantum dots (QDs) are measured after the dissolution in toluene. Luminescence spectra are obtained from alloyed CdSeTe QDs under 800 nm femtosecond laser excitation. With increasing pump fluence, the line width or full width at half maximum (FWHM) of photoluminescence (PL) spectrum becomes larger than 10 nm due to increasing temperature. Ultrafast spectroscopic properties of CdSeTe QDs are investigated by means of time-resolved PL, transient absorption (TA) and Z scan techniques. Moreover, open-aperture (OA) Z scan measurement is used to clarify the composition and pump fluence dependence of optical nonlinearity under femtosecond laser excitation. With increasing pump fluence, evolution from saturable absorption to reverse saturable absorption in CdSeTe QDs is observed. The transition process is analyzed via a phenomenological model based on nonlinear absorption coefficient and saturation intensity, which indicates that CdSeTe QDs have potential for applications in all-optical switching devices.

Dental Caries Status and Caries Risk Factors in Students Ages 12-14 Years in Zhejiang, China.

BACKGROUND An accurate and valid caries prevention policy is absent in Zhejiang because of insufficient data. Therefore, the aim of this study was to investigate oral health status and related risk factors in 12- to 14-year-old students in Zhejiang, China. MATERIAL AND METHODS Using multi-stage, stratified, random sampling, we recruited a total of 4860 students aged 12 to 14 years old from 6 regions in Zhejiang in this cross-sectional study. Dental caries was measured using the Decayed, Missing and Filled Teeth (DMFT) index and the Significant Caries Index (SiC). Information concerning family background and relevant behaviors was collected in a structured questionnaire. Logistic regression analysis was used to study risk factors related to dental caries. RESULTS The overall prevalence of dental caries was 44% and the mean DMFT and SiC scores were 1.14 and 3.11, respectively. Female students had a higher level of dental caries than male students (P<0.01). The annual increase in caries prevalence was 3% with increasing age, and the DMFT score was 0.15. The results of logistic regression analysis showed that female sex, older age, snacks consumption once or more per day, fair or poor self-assessment of dental health, toothache experience, and dental visits were the most significant risk factors for dental caries, with odds ratios ranging from 1.24 to 2.25 (P<0.01). CONCLUSIONS The prevalence of dental caries in 12- to 14-year-old students in Zhejiang was low, with a tendency to increase compared with previous oral surveys. Female sex, older age, increased sugar intake, poor oral health self-assessment, and bad dental experience were the most important factors increasing dental caries risks.

The combined effect of non-alcoholic fatty liver disease and metabolic syndrome on colorectal carcinoma mortality: a retrospective in Chinese females.

BACKGROUND: This research aimed to investigate whether metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD) had both individual and synergistic effects on the prognosis for female colorectal carcinoma (CRC) patients. METHODS: The relationship between CRC prognosis and NAFLD as well as MetS was evaluated in 764 female participants. Based on the NAFLD level, patients were divided into significant NAFLD (SNAFLD), "moderate" and "severe" level, and non-SNAFLD, "non" and "mild" level. All the patients were categorized into four subgroups according to the status of SNAFLD and MetS and then a comparison of CRC prognosis among those four groups was performed. RESULTS: NAFLD, SNAFLD, and MetS were independent factors for CRC-specific mortality with the adjustment of age and other confounders. The hazard ratio (HR) of CRC-specific mortality in MetS (+) SNAFLD (+) group was significantly higher than that in other three groups. Relative excess risk of interaction (RERI) was 2.203 with 95% CI ranged from 0.197 to 4.210, attributable proportion (AP) was 0.444 with range from 0.222 to 0.667, and synergy index (SI) of 2.256 with 95% CI from 1.252 to 4.065, indicating SNAFLD and MetS had a significant synergic effect on CRC-specific mortality. CONCLUSIONS: SNAFLD and MetS are independent risk factors for CRC-specific mortality in females. Moreover, those two diseases have a synergistic effect on promoting CRC-specific mortality.

Delayed Absorption of Oxidized Cellulose (Surgicel) in Post-Thyroidectomy Patients.

Delayed absorption of oxidized cellulose (Surgicel; Johnson & Johnson, New Brunswick, NJ) may mimic a pseudoabscess or a recurrent mass on sonography after tumor surgery. Here we present 3 cases of thyroidectomy in which Surgicel was still apparent on sonography after 26 to 47 months of follow-up. We show sonographic findings and discuss the utility of sonography for diagnosis of delayed absorption of Surgicel in post-thyroidectomy patients.