RESUMO
Sodium alginate (SA) biopolymer has been recognized as an efficient adsorbent material owing to their unique characteristics, including biodegradability, non-toxic nature, and presence of abundant hydrophilic functional groups. Accordingly, in the current research work, UiO-66-OH and UiO-66-(OH)2 metal organic framework (MOF) nanoparticles (NPs) have been integrated into SA biopolymer-based three-dimensional (3-D) membrane capsules (MCs) via a simple and facile approach to remove toxic metal cations (Cu2+ and Cd2+) from water and real sewage. The newly configured capsules were characterized by FTIR, SEM, XRD, EDX and XPS analyses techniques. Exceptional sorption properties of the as-developed capsules were ensured by evaluation of the pertinent operational parameters, i.e., contents of MOF-NPs (1-100 wt%), adsorbent dosage (0.001-0.05 g), content time (0-360 h), pH (1-8), initial concentration of metal cations (5-1000 mg/L) and reaction temperature (298.15-333.15 K) on the eradication of Cu2+ and Cd2+ metal cations. It was found that hydrophilic functional groups (-OH and -COOH) have performed an imperative role in the smooth loading of MOF-NPs into 3-D membrane capsules via intra/inter-molecular hydrogen bonding and van der waals potencies. The maximum monolayer uptake capacities (as calculated by the Langmuir isotherm model) of Cd2+ and Cu2+ by 3-D SGMMCs-OH were 940 and 1150 mg/g, respectively, and by 3-D SGMMCs-(OH)2 were 1375 and 1575 mg/g, respectively, under optimum conditions. The as-developed capsules have demonstrated superior selectivity against targeted metal cations under designated pH and maintained >80 % removal efficiency up to six consecutive treatment cycles. Removal mechanisms of metal cations by the 3-D SGMMCs-OH/(OH)2 was proposed, and electrostatic interaction, ion-exchange, inner-sphere coordination bonds/interactions, and aromatic ligands exchange were observed to be the key removal mechanisms. Notably, FTIR and XPS analysis indicated that hydroxyl groups of Zr-OH and BDC-OH/(OH)2 aromatic linkers played vital roles in Cu2+ and Cd2+ adsorption by participating in inner-sphere coordination interactions and aromatic ligands exchange mechanisms. The as-prepared capsules indicated >70 % removal efficiency of Cu2+ from real electroplating wastewater in the manifestation of other competitive metal ions and pollutants under selected experimental conditions. Thus, it was observed that newly configured 3-D SGMMCs-OH/(OH)2 have offered a valuable discernment into the development of MOFs-based water decontamination 3-D capsules for industrial applications.
Assuntos
Alginatos , Estruturas Metalorgânicas , Esgotos , Poluentes Químicos da Água , Purificação da Água , Alginatos/química , Estruturas Metalorgânicas/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Purificação da Água/métodos , Biopolímeros/química , Esgotos/química , Cobre/química , Membranas Artificiais , Cápsulas/química , Nanopartículas/química , Cátions/química , Concentração de Íons de Hidrogênio , Cádmio/química , Cádmio/isolamento & purificação , Água/químicaRESUMO
To develop a C-reactive protein-to-albumin ratio (CAR)-based nomogram for predicting the risk of in-hospital death in sepsis patients. Sepsis patients were selected from the MIMIC-IV database. Independent predictors were determined by multiple Cox analysis and then integrated to predict survival. The performance of the model was evaluated using the concordance index (C-index), receiver operating characteristic curve (ROC) analysis, and calibration curve. The risk stratifications analysis and subgroup analysis of the model in overall survival (OS) were assessed by Kaplan-Meier (K-M) curves. A total of 6414 sepsis patients were included. C-index of the CAR-based model was 0.917 [standard error (SE): 0.112] for the training set and 0.935 (SE: 0.010) for the validation set. The ROC curve analysis showed that the area under the curve (AUC) of the nomogram was 0.881 in the training set and 0.801 in the validation set. And the calibration curve showed that the nomogram performs well in both the training and validation sets. K-M curves indicated that patients with high CAR had significantly higher in-hospital mortality than those with low CAR. The CAR-based model has considerably high accuracy for predicting the OS of sepsis patients.
Assuntos
Proteína C-Reativa , Sepse , Humanos , Prognóstico , Nomogramas , Mortalidade Hospitalar , Biomarcadores , Albuminas , Sepse/diagnósticoRESUMO
Organic small-molecule semiconductor materials have attracted extensive attention because of their excellent properties. Due to the randomness of crystal orientation and growth location, however, the preparation of continuous and highly ordered organic small-molecule semiconductor nanocrystal arrays still face more challenges. Compared to organic macromolecules, organic small molecules exhibit better crystallinity, and therefore, they exhibit better semiconductor performance. The formation of organic small-molecule crystals relies heavily on weak interactions such as hydrogen bonds, van der Waals forces, and π-π interactions, which are very sensitive to external stimuli such as mechanical forces, high temperatures, and organic solvents. Therefore, nanocrystal array engineering is more flexible than that of the inorganic materials. In addition, nanocrystal array engineering is a key step towards practical application. To resolve this problem, many conventional nanocrystal array preparation methods have been developed, such as spin coating, etc. In this review, the typical and recent progress of nanocrystal array engineering are summarized. It is the typical and recent innovations that the array of nanocrystal array engineering can be patterned on the substrate through top-down, bottom-up, self-assembly, and crystallization methods, and it can also be patterned by constructing a series of microscopic structures. Finally, various multifunctional and emerging applications based on organic small-molecule semiconductor nanocrystal arrays are introduced.
RESUMO
Objective@# To compare the efficiency of four methods that remove calcium hydroxide in root canals and to guide clinical practice. @* Methods @# Sixty-five isolated mandibular single root canal premolars were collected. After crown cutting and root canal preparation, a tooth was randomly selected as the blank control group, and the remaining 64 teeth were equally divided into Groups A and B (n = 32). Group A was injected with water-soluble calcium hydroxide, and Group B was injected with oil-soluble calcium hydroxide. After 2 weeks of drug sealing, Groups A and B were randomly divided into 4 groups (n = 8), including the lateral opening syringe group, sonic vibration group, ultrasonic group, and Er: YAG laser group. Before and after calcium hydroxide removal, the samples were scanned by cone-beam CT, and the data were imported into Mimics for 3D reconstruction. The root canal was divided into the following segments: superior root segment, middle and apical, and the calcium hydroxide volume of each segment of the root canal was calculated. The volumes of calcium hydroxide before and after removal were V1 and V2, respectively, with a clearance rate = (V1-V2)/V1×100%. Three-factor ANOVA was used for statistical analysis. After Groups A and B were reconstructed, the apical region with residual calcium hydroxide was selected, and the blank control was observed by scanning electron microscopy (SEM). @*Results @# Two types of calcium hydroxide could not be completely removed by the four flushing methods. The clearance rate of water-soluble calcium hydroxide was higher than that of oil-soluble calcium hydroxide (P<0.001). Among the three segments of the root canal, the clearance rate of the apical segment was lower (P<0.05). The Er: YAG laser treatment group showed the highest removal efficiency of two kinds of calcium hydroxide, which was higher than that of the other groups, especially in apical of the root. Compared with the sonic wave washing group and the syringe washing group, the ultrasonic wave washing group exhibited significant advantages (P<0.05). The clearance rate of the sonic wave washing group was higher in the oily calcium hydroxide root middle group than in the syringe washing group (P<0.05). SEM showed that the two kinds of calcium hydroxide could not be completely removed, but the residual rate of oil-soluble calcium hydroxide was large.@*Conclusion @# Both types of calcium hydroxide could not be completely removed, and compared to water-soluble calcium hydroxide, oil-soluble calcium hydroxide was more difficult to remove. Among the four cleaning methods, Er:YAG laser swing washing showed the higher cleaning efficiency.
RESUMO
Thermal management is a critical task for highly integrated or high-power semiconductor devices. Low dimensional materials including graphene and single-layer hexagonal boron nitride (BN) are attractive candidates for this task because of their high thermal conductivity, semi-conductivity and other excellent physical properties. The similarities in crystal structure and chemistry between graphene and boron nitride provide the possibility of constructing graphene/BN heterostructures bearing unique functions. In this paper, we investigated the interfacial thermal transport properties of graphene/BN nanosheets via non-equilibrium molecular dynamics (NEMD) simulations. We observed a significant thermal rectification behavior of these graphene/BN nanosheets, and the rectification ratio increased with the system length increases up to 117%. This phenomenon is attributed to the mismatch of out-of-plane phonon vibration modes in two directions at the interface. In addition, we explored the underlying mechanism of the length dependence of the thermal transport properties. The results show promise for the thermal management of this two-dimensional heterostructure in an actively tunable manner.
RESUMO
The stability and applicability of UiO-66-(NH2)2 metal-organic framework (MOF) nanoparticles (NPs) were successfully improved in this study by incorporating them into alginate biopolymer during the manifestation of crosslinking agents-calcium chloride and glutaraldehyde-via a simple, environment-friendly, and facile approach to eradicate potentially toxic metals (PTMs) such as Cr6+, Cr3+, Cu2+, and Cd2+ from water and real electroplating wastewater. Hydrophilic functional groups (i.e., -OH, -COOH, and -NH2) are imperative in the smooth loading of UiO-66-(NH2)2 MOF- NPs into three-dimensional (3-D) membrane capsules (MCs). The X-ray photoelectron spectroscopy (XPS) results suggested that UiO-66-(NH2)2 MOF was effectively bonded in/on the capsule via electrostatic crosslinking between -H3N+ and -COO-. Scanning electron microscopy results revealed a porous honeycomb configuration of the 3-D SGMMCs (S: sodium alginate, G: glutaraldehyde, M: MOF NPs, and MCs: membrane capsules). The maximum monolayer absorption capacities for Cr6+, Cr3+, Cu2+, and Cd2+ were 495, 975, 1295, and 1350 mg/g, respectively. The results of Fourier transform infrared spectroscopy and XPS analyses showed that electrostatic attraction and ion exchange were the main processes for PTM removal used by the as-developed 3-D SGMMCs. The as-developed 3-D SGMMCs exhibited outstanding selectivity for removing the targeted PTMs under the specified pH/conditions and maintained >80% removal efficiency for up to six consecutive treatment cycles. Notably, > 60% removal efficiencies for Cr6+ and Cu2+ were observed when treating real electroplating wastewater. Therefore, the as-developed 3-D SGMMCs can be used as an exceptional multifunctional sorbent to remove and recover PTMs from real electroplating wastewater.
Assuntos
Estruturas Metalorgânicas , Poluentes Químicos da Água , Adsorção , Alginatos , Cádmio , Cloreto de Cálcio , Cápsulas , Galvanoplastia , Glutaral , Concentração de Íons de Hidrogênio , Ácidos Ftálicos , Águas Residuárias/química , Água , Poluentes Químicos da Água/análiseRESUMO
The disinfection of root canal through minimally invasive access cavity remains questionable. This in vitro study compared the effectiveness of three disinfection measures including conventional irrigation, ultrasonic assisted irrigation, and erbium:yttrium-aluminum-garnet (Er:YAG) laser assisted irrigation through conventionally or minimally invasive access. Sixty-six extracted maxillary first molars were randomly divided into group 1 conventionally invasive access group (CIA) and group 2 computer-guided minimally invasive access group (MIA). Each group was further randomly divided into three subgroups, (A) conventional irrigation (CI), (B) passive ultrasonic agitation (PUI), and (C) Er:YAG laser activated irrigation (LAI). Enterococcus faecalis (E. faecalis) infection model was established inside all root canals after instrumentation was performed up to ProTaper Universal F2. After various disinfection methods, microbial samples were collected from root canals by paper tip method and cultured, and colony forming units (CFU) values of each sample were calculated. Then the root canals were enlarged to the size of F3, after which dentin debris was collected from the F3 file. After dilution and culturing, the CFU value was calculated for each group. Two-way analysis of variance (ANOVA) was performed to test the interaction. The results revealed a significant antagonism (F = 3.394, P = 0.043). The bacterial CFU counts of group B and group C were significantly less than that of group A (P < 0.05), and there was no significant difference between group B and C (P > 0.05). Additionally, group 2A was better than group 1A (P < 0.05); there was no significant difference between group 1B and group 2B, group 1C and group 2C (P > 0.05). Comparison of the bacterial CFU counts in dentin debris after disinfection, the results revealed a significant antagonism (F = 7.224, P = 0.002), and group C had the least. The disinfection effect of Er:YAG laser or ultrasonic assisted computer-guided minimally invasive access is similar to conventionally invasive access, and Er:YAG laser is better than ultrasonic in removing bacteria from dentinal tubules and is easy to operate, which is more suitable for minimally invasive root canal treatment.
Assuntos
Lasers de Estado Sólido , Cavidade Pulpar , Desinfecção/métodos , Enterococcus faecalis , Érbio , Lasers de Estado Sólido/uso terapêutico , Irrigantes do Canal Radicular/farmacologia , Preparo de Canal Radicular/métodos , Hipoclorito de Sódio/farmacologia , UltrassomRESUMO
PURPOSE: To obtain an efficient and simple root canal disinfection method based on minimally invasive root canal treatment by comparing different root canal disinfection methods between minimally invasive root canal treatment and conventional root canal treatment. METHODS: Sixty-six extracted maxillary first molars were randomly divided into experimental group (computer-guided precision minimally invasive root canal treatment) and control group (conventional root canal treatment). All teeth were prepared to ProTaper universal F2, and Enterococcus faecalis infection models were established.Each group was randomly divided into three subgroups, sodium hypochlorite+EDTA root canal irrigation, sodium hypochlorite+EDTA+ultrasonic and sodium hypochlorite +EDTA +Er: YAG laser. After root canal disinfection,the samples were collected by paper tip method and cultured, and colony forming units (CFU) values of each sample were calculated. Then dentin debris was prepared and collected with F3 file. After being diluted and cultured, the CFU value was calculated. Statistical analysis was performed by SPSS 26.0 software package. RESULTS: Comparison of the amount of bacterial inner wall of root canal between the experimental group and the control group showed that the germicidal efficacy of group C and group B were significantly better than that of group A (Pï¼0.05), but there was no significant difference between group B and group C(Pï¼0.05). In the experimental group, there was significant difference between group B1, C1 and A1 (Pï¼0.05). The results of group B1 and C1 were lower than that of group A1, but there was no significant difference between group B1 and group C1(Pï¼0.05). In the control group, there were significant differences between group B2, C2 and A2 (Pï¼0.05). The results of group B2 and C2 were lower than that of group A2, but there was no significant difference between group B2 and C2(Pï¼0.05). Comparison of the amount of bacteria in dentin debris between the experimental group and the control group showed that the effect of group C was the best, followed by group B, and group A, and there were significant differences between three groups(Pï¼0.05). CONCLUSIONS: The disinfection effect of Er:YAG laser or ultrasound assisted computer-guided precision minimally invasive root canal treatment is similar to conventional root canal treatment, and Er:YAG laser is better than ultrasound in removing bacteria from dentinal tubules, which is more suitable for minimally invasive root canal treatment.
Assuntos
Enterococcus faecalis , Hipoclorito de Sódio , Cavidade Pulpar/microbiologia , Desinfecção/métodos , Ácido Edético , Irrigantes do Canal Radicular , Preparo de Canal Radicular/métodos , Hipoclorito de Sódio/farmacologiaRESUMO
After removal of a large frontal sinus osteoma in this case, the contralateral nasofrontal canal was opened to drain the intraoperative fluid and prevent infection, and the defect in the orbitofrontal area was restored using a titanium mesh designed with 3D printing technology.
RESUMO
Organic smart fluorophores (OSFs) are highly desirable over the past decades because of their potential applications in advanced photonic devices. However, it is still difficult and challenging to obtain such materials with tunable photophysical properties and high emission efficiency based on robust construction strategies. Therefore, we proposed a simple and efficient strategy for constructing OSFs by balancing the competition between intermolecular interactions and external stimuli via molecular structure design. In this work, four pyrene derivatives (T1-Py, T4-Py, T12-Py, and S12-Py) with tunable stimuli-responsive properties were designed and synthesized. The tunable intermolecular interactions in solution states were successfully demonstrated by the molecular structure and solution concentration-dependent luminescence properties. The effect of alkyl chain length on molecular packing in solid states was investigated by polarized optical microscopy and powder and single-crystal X-ray diffraction; the results show that with the increase in molecular chain length, the molecular packing of the compounds gradually changed from π-π stacked compact mode to X-crossing stacked loose mode, which leads to different stimuli-responsive phenomena of these compounds. The strategy provided herein facilitates the construction of multistimuli-responsive (thermochromism, mechanochromism, and vapochromism) OSFs with adjustable emission color. Harnessing the heat-responsive luminescence properties and great solubility of T12-Py, the optical information anticounterfeiting based on temperature was demonstrated by printing different concentrations of T12-Py solution on filter papers. Much more, this research may provide broad implications for the design of organic smart materials based on intermolecular interactions.
RESUMO
With large interstitial space volumes and fast ion diffusion pathways, amorphous metal oxides as cathodic intercalation materials for electrochromic devices have attracted attention. However, these incompact thin films normally suffer from two inevitable imperfections: self-deintercalation of guest ions and poor stability of the structure, which constitute a big obstacle toward the development of high-stable commercial applications. Here, we present a low-cost, eco-friendly hybrid cation 1,2-PG-AlCl3·6H2O electrolyte, in which the sputter-deposited a-WO3-x thin film can exhibit both the long-desired excellent open-circuit memory (>100 h, with zero optical loss) and super-long cycling lifetime (â¼20,000 cycles, with 80% optical modulation), benefiting from the formation of unique Al-hydroxide-based solid electrolyte interphase during electrochromic operations. In addition, the optical absorption behaviors in a-WO3-x caused by host-guest interactions were elaborated. We demonstrated that the intervalence transfers are primarily via the "corner-sharing" related path (W5+ â W6+) but not the "edge-sharing" related paths (W4+ â W6+ and/or W4+ â W5+), and the small polaron/electron transfers taking place at the W-O bond-breaking positions are not allowed. Our findings might provide in-depth insights into the nature of electrochromism and provide a significant step in the realization of more stable, more excellent electrochromic applications based on amorphous metal oxides.
RESUMO
A study was carried out to determine systematically the key aroma-active compounds of Langyatai Baijiu with Jian flavour (LBJF) using sensory omics analysis (SOA). A total of 56 odorants were screened out using gas chromatography-olfactometry-mass spectrometry (GC-O-MS)/Osme analysis. Among them, 15 aroma-active components were first identified. After quantitation, 30 odorants had odour activity values (OAVs) > 1.0 in LBJF. Recombinant and omission experiments proved that the esters, alcohols, acids, especially ethyl hexanoate, γ-nonalactone, and dimethyl trisulfide, were critical to the flavour of LBJF. The basic and commercial liquors had obvious differences in the skeleton compositions of esters and acids. This study uncovers the characteristics of Jian flavour Baijiu (JFB) and provides a scientific basis for the quality control of JFB, which is helpful for the development of Chinese Baijiu flavour styles.
Assuntos
Bebidas Alcoólicas/análise , Análise de Alimentos/métodos , Odorantes/análise , Paladar , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Olfatometria , Compostos Orgânicos Voláteis/análiseRESUMO
Two-photon absorption spectra are difficult to observe using direct absorption spectroscopy especially in the near-infrared region. Cavity ring-down spectroscopy is a promising absorption spectroscopy technique which has been widely applied to linear and saturated single-photon absorption spectra. In the present study, we report the observation of a possible two-photon absorption in the near-infrared using cavity ring-down spectroscopy, namely a two-photon resonance of methane. Using an optical frequency comb, the single-photon wavenumber of the double-quantum transition has been determined to be 182 207 682.645 MHz with a standard deviation of 75 kHz.
RESUMO
In this study, an image registration algorithm was applied to calculate the rotation angle of objects when matching images. Some commonly used image feature detection algorithms such as features from accelerated segment test (FAST), speeded up robust features (SURF) and maximally stable extremal regions (MSER) algorithms were chosen as feature extraction components. Comparing the running time and accuracy, the image registration algorithm based on SURF has better performance than the other algorithms. Accurately obtaining the roll angle is one of the key technologies to improve the positioning accuracy and operation quality of agricultural equipment. To acquire the roll angle of agriculture machinery, a roll angle acquisition model based on the image registration algorithm was built. Then, the performance of the model with a monocular camera was tested in the field. The field test showed that the average error of the rolling angle was 0.61°, while the minimum error was 0.08°. The field test indicated that the model could accurately obtain the attitude change trend of agricultural machinery when it was working in irregular farmlands. The model described in this paper could provide a foundation for agricultural equipment navigation and autonomous driving.
RESUMO
OBJECTIVES: Previous cohort studies have reported the significant association between tooth loss and functional disability in aging adults. This study aimed to examine whether eating and communication difficulties mediate this association. METHODS: Data from wave 7 (2014-2015) to wave 8 (2016-2017) of the English Longitudinal Study of Ageing (ELSA) were analyzed. Severe tooth loss was defined as "< 20 teeth remaining" at baseline. Eating and communication difficulties were assessed through a questionnaire. Onset of functional disability 2-year later was assessed by activities of daily living (ADL) scale and instrumental ADL (IADL) scale. Baron and Kenny's causal steps and Karlson/Holm/Breen (KHB) method were used to examine the mediating effect. RESULTS: At baseline, 7,830 participants had no ADL disability and 7,678 participants had no IADL disability. The 2-year cumulative incidence of ADL disability and IADL disability were 7.5 % and 9.0 %, respectively. Severe tooth loss was associated with both incidence of ADL disability (ORâ¯=â¯1.40; 95 % CIâ¯=â¯1.13-1.74) and incidence of IADL disability (ORâ¯=â¯1.24; 95 % CIâ¯=â¯1.01-1.52). The mediating effect of eating difficulty on the association between severe tooth loss and ADL disability was 1.04 (95 % CI: 1.01, 1.06). The mediating effect of communication difficulty on the association between severe tooth loss and IADL disability was 1.05 (95 % CI: 1.02, 1.07). CONCLUSION: Severe tooth loss is associated with incidence of functional disability in middle-aged and older English adults. Eating and communication difficulties play the role as mediators in these associations. CLINICAL SIGNIFICANCE: This prospective study contributes to elucidating parts of biological mechanism underlying tooth loss and functional disability in middle-aged and older adults. It suggests that oral health strategies aimed to protect teeth may be important in reducing the risk of functional disability.
Assuntos
Pessoas com Deficiência , Perda de Dente , Atividades Cotidianas , Idoso , Avaliação da Deficiência , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Estudos Prospectivos , Perda de Dente/epidemiologiaRESUMO
PURPOSE: To assess the effect of oral comprehensive healthcare on the prevalence of early childhood caries in urban areas of China. MATERIALS AND METHODS: A total of 398 children aged 4-5 years from six different kindergartens in Qingdao were recruited to participate in a 1-year single-blind randomised controlled clinical trial. They were randomly assigned into either an experimental group (187 children) or a control group (211 children). The experimental group received comprehensive oral healthcare including oral health examinations, oral health education for children and their guardians, and local fluoride application and dental treatment, whereas children in the control group only received oral health examinations twice a year. The children's parents finished a comprehensive oral health questionnaire before and after the experiment. After a year, the oral health status of two groups of children was statistically analysed to determine the effect of oral comprehensive healthcare on early childhood caries. RESULTS: After 1 year, the numbers of decayed teeth (dt), decayed tooth surfaces (ds), filled teeth (ft), and filled tooth surfaces (fs) in the experimental group were significantly lower than the control group (p <0.001). The dmft and dmfs were also significantly different between the two groups (p <0.05). Statistically significant differences were additionally shown in oral hygiene habits and eating habits of both the children and their parents in the two groups compared with 1 year before (all p <0.001). CONCLUSION: Implementation of comprehensive oral healthcare measures both prevents and reduces early childhood caries.
Assuntos
Cárie Dentária , Criança , Pré-Escolar , China , Assistência Integral à Saúde , Índice CPO , Seguimentos , Humanos , Método Simples-Cego , Inquéritos e QuestionáriosRESUMO
Accurately obtaining roll angles is one of the key technologies to improve the positioning accuracy and operation quality of agricultural equipment. Given the demand for the acquisition of agricultural equipment roll angles, a roll angle monitoring model based on Kalman filtering and multi-source information fusion was established by using the MTi-300 AHRS inertial sensor (INS) and XW-GI 5630 BeiDou Navigation Satellite System (BDS), which were installed on agricultural equipment. Data of the INS and BDS were fused by MATLAB; then, Kalman filter was used to optimize the data, and the state equation and measurement equation of the integrated system were established. Then, an integrated monitoring terminal man-machine interactive interface was designed on MATLAB GUI, and a roll angle monitoring system based on the INS and BDS was designed and applied into field experiments. The mean absolute error of the integrated monitoring system based on multi-source information fusion during field experiments was 0.72°, which was smaller compared with the mean absolute errors of roll angle monitored by the INS and BDS independently (0.78° and 0.75°, respectively). Thus, the roll angle integrated model improves monitoring precision and underlies future research on navigation and independent operation of agricultural equipment.
RESUMO
PURPOSE: In order to achieve accurate and minimally invasive root canal treatment and enhance the fracture resistance of tooth tissue after root canal therapy, this study explores digital guided mediated minimally invasive root canal treatment and compares it with conventional root canal treatment to provide a more favorable method for clinical practice. METHODS: Forty freshly extracted first permanent molars were randomly divided into control group and experimental group. Teeth in the control group were treated with conventional root canal treatment, while teeth in the experimental group were treated with precise minimally invasive root canal treatment. The difference between the time of opening of the pulp chamber and the area of the open pores on the total area of the occlusal surface was compared. Loading test was carried out on the subjects using a universal testing machine, and the fracture resistence of the tooth tissues of the two groups were measured. Statistical analysis was performed using SPSS 24.0 software package. RESULTS: In the control group, the time required for opening the pulp chamber was (1.85±0.05) min, the open pore area was (9.18±0.48)% of the total occlusal area, and the load of the tooth tissue was (1.48±0.07) kN. In the experimental group, the time required was (0.72±0.10) min, the open pore area was (3.53±0.13)% of the total occlusal area, and the load of the tooth tissue was (1.81±0.03) kN. The higher the loading value, the stronger the fracture resistance of the tooth tissue. Compared with traditional root canal treatment, digital guided plate mediated minimally invasive root canal treatment had the advantages of short time, small access cavity and strong fracture resistance of tooth tissue. The difference between the two groups was significant (P<0.01). CONCLUSIONS: Digital guided plate-mediated accurate minimally invasive root canal treatment can reduce the occlusal area, shorten the operation time beside the chair, retain more healthy tooth tissue, enhance the fracture resistance of tooth tissue after root canal treatment, and improve the retention rate of affected teeth.
Assuntos
Fraturas dos Dentes , Dente não Vital , Cavidade Pulpar , Humanos , Dente Molar , Preparo de Canal Radicular , Tratamento do Canal RadicularRESUMO
Cell-based tissue engineering is a promising alternative for periodontal regeneration as current therapies fail to reconstitute tissue damage caused by periodontitis. As newly identified postnatal stem cells, gingiva-derived mesenchymal stem cells (GMSCs) have been focused on for isolation and expansion in vitro of cells with multi-differentiation potential and immunomodulatory capacities. It has been demonstrated that systemically delivered GMSCs can home to the mandibular bone defect sites and promote bone regeneration. However, the role of transplanted GMSCs in the treatment of periodontitis has not been reported. In the present study, GMSCs were transplanted into C57BL/6J mice with periodontitis via the tail vein to investigate the contribution of GMSCs to periodontal tissue regeneration. Results demonstrated that the alveolar bone heights of mice with transplanted GMSCs were significantly increased compared with the control groups and GMSCs were detected in newly formed periodontal ligament and alveolar bone. The results of the present study implied that systemically transplanted GMSCs could home to periodontal injury sites and promote periodontal tissue regeneration.
RESUMO
Deep ultraviolet (DUV) photodetectors have wide-range applications in satellite communications, air purification, and missile-plume detection. However, the critical barriers for the currently available wide-band gap semiconductor film-based DUV photodetectors are their low efficiency, complicated processes, and lattice mismatch with the substrate. Quantum dot (QD) devices prepared using solution-based methods can solve these problems. However, so far, there are no reports on photovoltaic-type DUV photodetectors using QDs. In this study, we propose a novel methodology to construct a hybrid zero-/two-dimensional DUV photodetector (p-type graphene/ZnS QDs/4H-SiC) with photovoltaic characteristics. The device exhibits excellent selectivity for the DUV light and has an ultrafast response speed (rise time: 28 µs and decay time: 0.75 ms), which are much better than those reported for conventional photoconductive photodetectors.