Isocorydine Exerts Anticancer Activity by Disrupting the Energy Metabolism and Filamentous Actin Structures of Oral Squamous Carcinoma Cells.

Isocorydine (ICD) exhibits strong antitumor effects on numerous human cell lines. However, the anticancer activity of ICD against oral squamous cell carcinoma (OSCC) has not been reported. The anticancer activity, migration and invasion ability, and changes in the cytoskeleton morphology and mechanical properties of ICD in OSCC were determined. Changes in the contents of reactive oxygen species (ROS), the mitochondrial membrane potential (MMP), ATP, and mitochondrial respiratory chain complex enzymes Ⅰ-Ⅳ in cancer cells were studied. ICD significantly inhibited the proliferation of oral tongue squamous cells (Cal-27), with an IC50 of 0.61 mM after 24 h of treatment. The invasion, migration, and adhesion of cancer cells were decreased, and cytoskeletal actin was deformed and depolymerized. In comparison to an untreated group, the activities of mitochondrial respiratory chain complex enzymes I-IV were significantly decreased by 50.72%, 27.39%, 77.27%, and 73.89%, respectively. The ROS production increased, the MMP decreased by 43.65%, and the ATP content decreased to 17.1 ± 0.001 (mmol/mL); ultimately, the apoptosis rate of cancer cells increased up to 10.57% after 24 h of action. These findings suggest that ICD exerted an obvious anticancer activity against OSCC and may inhibit Cal-27 proliferation and growth by causing mitochondrial dysfunction and interrupting cellular energy.

Research on the visual location method for strawberry picking points under complex conditions based on composite models.

BACKGROUND: Strawberry, being an important economic crop, requires a large amount of human labor for harvesting operations. Efficient and non-destructive harvesting by strawberry harvesting robots requires the precise location of the picking points. Current algorithms for locating picking points encounter significant issues with location errors and minimal effective information in complex situations. RESULTS: To improve the accuracy of the location of picking points, this study proposes a visual location method based on composite models. This method employs object detection and instance segmentation models to detect fruits and segment peduncles sequentially, thereby enabling the identification of picking points and inclination on the peduncle. Different object detection algorithms and instance segmentation models were validated to explore the optimal model combination, and the Convolutional Block Attention Module (CBAM) was integrated into YOLOv8s-seg to construct YOLOv8s-seg-CBAM. Test results show that the composite model built with YOLOv8s and YOLOv8s-seg-CBAM achieved a peduncle detection accuracy of 86.2%, with an inference time of 30.6 ms per image. CONCLUSION: The picking point visual location method based on YOLOv8s and YOLOv8s-seg-CBAM composite models can better balance accuracy and efficiency and can provide more accurate guidance for automated harvesting. © 2024 Society of Chemical Industry.

Extracellular vesicles derived from PM2.5-exposed alveolar epithelial cells mediate endothelial adhesion and atherosclerosis in ApoE-/- mice.

Epidemiological studies suggested that PM2.5 (particle matters with an aerodynamic diameter ≤2.5 µm) exposure is associated with atherosclerosis. Extracellular vesicles (EVs) are messengers between intracellular communications which are important in diseases procession. At present, whether EVs derived from PM2.5-exposed alveolar epithelial cells (P-EVs) involve in atherosclerosis has not been clearly understood. This study is performed to investigate the effects of P-EVs on the development of endothelium adhesion and atherosclerosis. Here, ApoE-/- mice were randomized into different groups receiving one of the following treatments, filtered air (FA), PM2.5, PBS, PBS-treated alveolar epithelial cells-derived EVs (EVs), or P-EVs. Then the atherosclerosis level in aortas or aorta sections was evaluated by oil red O staining. The results indicated that ApoE-/- mice treated with P-EVs or PM2.5 showed more obvious atherosclerosis plaques in aortas and aortic arches than those treated with EVs or PBS. Endothelial cells (ECs) were treated with PBS, EVs, P-EVs, or PM2.5. The adhesion property, miRNAs level and expressions of IκBα, phosphorylated IκBα, NF-κB p65, phosphorylated NF-κB p65, and VCAM1 in ECs were determined. It was found that P-EVs activated IκBα-NF-κB-VCAM1 signaling and increased adhesion of ECs, and such effects could be reversed by adalimumab (the TNF-α inhibitor) or miR-326-3p inhibitor. Further study suggested that P-EVs induced upregulation of TNF-α and miR-326-3p in recipient ECs and contributed to the phosphorylation of NF-κB p65. Collectively, EVs derived from PM2.5-exposed alveolar epithelial cells played an important role in the development of atherosclerosis via activating IκBα-NF-κB-VCAM1 signaling.

Diverse long-term potentiation and depression based on multilevel LiSiOxmemristor for neuromorphic computing.

Memristor-based neuromorphic computing is expected to overcome the bottleneck of von Neumann architecture. An artificial synaptic device with continuous conductance variation is essential for implementing bioinspired neuromorphic systems. In this work, a memristor based on Pt/LiSiOx/TiN structure is developed to emulate an artificial synapse, which shows non-volatile multilevel resistance state memory behavior. Moreover, the high nonlinearity caused by abrupt changes in the set process is optimized by adjusting the initial resistance. 100 levels of continuously modulated conductance states are achieved and the nonlinearity factors are reduced to 1.31. The significant improvement is attributed to the decrease in the Schottky barrier height and the evolution of the conductive filaments. Finally, due to the improved linearity of the long-term potentiation/long-term depression behaviors in LiSiOxmemristor, a robust recognition rate (∼94.58%) is achieved for pattern recognition with the modified National Institute of Standards and Technology handwriting database. The Pt/LiSiOx/TiN memristor shows significant potential in high-performance multilevel data storage and neuromorphic computing systems.

Long non-coding RNAs MALAT1 and NEAT1 in non-syndromic orofacial clefts.

Long non-coding RNAs (lncRNAs) are thought to play important roles in non-syndromic orofacial clefts (NSOFC). Clinical diagnosis was categorized as either non-syndromic cleft lip with or without cleft palate (NSCL/P), or non-syndromic cleft palate only (NSCPO). Tissues excised from the trimmed wound edge were reserved as experimental samples; adjacent normal control was used as a positive control, and tissue from healthy individuals was used as a blank control. Target lncRNAs in the collected tissues were identified using microarrays and quantitative reverse transcription PCR (RT-qPCR). Immunohistochemical (IHC) staining and RT-qPCR were used to verify the target mRNAs. Pathway, gene ontology (GO) enrichment, and TargetScan predictions were employed to construct competing endogenous RNA networks (ceRNA networks) and explore their potential functions. RNA-Seq revealed 24 upregulated and 43 downregulated lncRNAs; MALAT1 and NEAT1 were screened and validated using RT-qPCR. Common NSOFC risk factors were positively correlated with MALAT1 and NEAT1 expression. Bioinformatics predicted four ceRNA networks; GO enrichment focused on their potential functions. RT-qPCR and IHC data were consistent with respect to expression levels of proteins and the mRNAs that encode them. As MALAT1 and NEAT1 are associated with the severity of NSOFC, they represent potential therapeutic targets and prognostic biomarkers.

Direct Electrochemistry of Glucose Dehydrogenase-Functionalized Polymers on a Modified Glassy Carbon Electrode and Its Molecular Recognition of Glucose.

A glucose biosensor was layer-by-layer assembled on a modified glassy carbon electrode (GCE) from a nanocomposite of NAD(P)+-dependent glucose dehydrogenase, aminated polyethylene glycol (mPEG), carboxylic acid-functionalized multi-wall carbon nanotubes (fMWCNTs), and ionic liquid (IL) composite functional polymers. The electrochemical electrode was denoted as NF/IL/GDH/mPEG-fMWCNTs/GCE. The composite polymer membranes were characterized by cyclic voltammetry, ultraviolet-visible spectrophotometry, electrochemical impedance spectroscopy, scanning electron microscopy, and transmission electron microscopy. The cyclic voltammogram of the modified electrode had a pair of well-defined quasi-reversible redox peaks with a formal potential of -61 mV (vs. Ag/AgCl) at a scan rate of 0.05 V s-1. The heterogeneous electron transfer constant (ks) of GDH on the composite functional polymer-modified GCE was 6.5 s-1. The biosensor could sensitively recognize and detect glucose linearly from 0.8 to 100 µM with a detection limit down to 0.46 µM (S/N = 3) and a sensitivity of 29.1 nA µM-1. The apparent Michaelis-Menten constant (Kmapp) of the modified electrode was 0.21 mM. The constructed electrochemical sensor was compared with the high-performance liquid chromatography method for the determination of glucose in commercially available glucose injections. The results demonstrated that the sensor was highly accurate and could be used for the rapid and quantitative determination of glucose concentration.

ATP synthase inhibitory factor subunit 1 regulates islet ß-cell function via repression of mitochondrial homeostasis.

Mitochondrial homeostasis is crucial for the function of pancreatic ß-cells. ATP synthase inhibitory factor subunit 1 (IF1) is a mitochondrial protein interacting with ATP synthase to inhibit its enzyme activity. IF1 may also play a role in maintaining ATP synthase oligomerization and mitochondrial inner membrane formation. A recent study confirmed IF1 expresses in ß-cells. IF1 knockdown in cultured INS-1E ß-cells enhances glucose-induced insulin release. However, the role of IF1 in islet ß-cells remains little known. The present study investigates islets freshly isolated from mouse lines with global IF1 knockout (IF1-/-) and overexpression (OE). The glucose-stimulated insulin secretion was increased in islets from IF1-/- mice but decreased in islets from IF1 OE mice. Transmitted Electronic Microscopic assessment of isolated islets revealed that the number of matured insulin granules (with dense core) was relatively higher in IF1-/-, but fewer in IF1 OE islets than those of controlled islets. The mitochondrial ultrastructure within ß-cells of IF1 overexpressed islets was comparable with those of wild-type mice, whereas those in IF1-/- ß-cells showed increased mitochondrial mass. Mitochondrial network analysis in cultured INS-1 ß-cells showed a similar pattern with an increased mitochondrial network in IF1 knockdown cells. IF1 overexpressed INS-1 ß-cells showed a compromised rate of mitochondrial oxidative phosphorylation with attenuated cellular ATP content. In contrast, INS-1 cells with IF1 knockdown showed markedly increased cellular respiration with improved ATP production. These results support that IF1 is a negative regulator of insulin production and secretion via inhibiting mitochondrial mass and respiration in ß-cells. Therefore, inhibiting IF1 to improve ß-cell function in patients can be a novel therapeutic strategy to treat diabetes.

Self-Assembly of Metal-Organic Frameworks on Graphene Oxide Nanosheets and In Situ Conversion into a Nickel Hydroxide/Graphene Oxide Battery-Type Electrode.

Graphene oxide (GO) has been widely reported as a supercapacitor electrode. Especially, GO is usually utilized to composite with electrochemical active materials, such as transition-metal oxide/hydroxide/sulfide, due to its considerable conductivity and mechanical strength. However, the ideal design and treatment for compositing GO with active materials are still challenging. Herein, an Ni-metal-organic framework (MOF) was self-assembled on GO nanosheets via the solvothermal method and was subsequently etched into the Ni(OH)2-GO composite electrode material through a gentle hydrolysis strategy. The GO support enables fast electron transport within the composite material, and the nickel hydroxide growth on GO nanosheets can prevent their aggregation, guaranteeing rapid ion migration. The improved Ni(OH)2-GO battery-type electrode features outstanding stability (capacity retention of 108% at 8000 cycles) and a considerable specific capacity (SC) of 1007.5 C g-1 at a current density of 0.5 A g-1. Compared with MOF-derived Ni(OH)2 obtained through hydrolysis, Ni(OH)2-GO only contains 7.41% wt GO, while its SC is almost 50% higher. An asymmetric supercapacitor has an energy density of 65.22 W h kg-1 and a power density of 395.27 W kg-1 utilizing p-phenylenediamine-functional reduced GO as the negative electrode, and it can maintain 73.08% capacity during 8000 cycles at a current density of 5 A g-1.

Flexible Microswimmer Manipulation in Multiple Microfluidic Systems Utilizing Thermal Buoyancy-Capillary Convection.

Flexible and accurate control of microswimmers is significant for lots of applications. Herein, we present a method for effective microswimmer manipulation in multiple microfluidic systems by thermal buoyancy-capillary convection. In the microdevice, four strips of microheaters arranged at the bottom of the microchannel are used to unevenly heat microfluids, and the convection flow forms under the influence of gravity and interfacial tension gradient. By adjusting the DC signals applied on these four heating elements, the intensity and direction of convection flow can be flexibly adjusted. Accordingly, granular samples dispersed in liquid buffer can be controllably driven to the target position by the Stokes drag. The swimming behavior of polystyrene (PS) microspheres at the solid-liquid interface of the device is first investigated. It shows that the PS microswimmers can migrate along various geometrical patterns by powering the microheaters with designed voltage combinations, and the migration velocity is positively affected by the increased voltage. Then, the butyl acrylate (BA) microswimmers are manipulated at the gas-liquid interface of the microchip. It turns out that the BA microswimmers migrate oppositely compared with PS swimmers under the same energization strategy. Additionally, the translation direction of BA swimmers can be changed over a 360° range by different voltage combinations. The multifunctionality of our approach is further demonstrated by conveniently driving the trimethylolpropane triacrylate microswimmers at the liquid-liquid interface of the microplatform along different directions and pathlines. Therefore, this technique can be promising for many cases needing granular sample control, such as cargo delivery and sensing.

The lipid-lowering drug fenofibrate combined with si-HOTAIR can effectively inhibit the proliferation of gliomas.

BACKGROUND: Fenofibrate is a fibric acid derivative known to have a lipid-lowering effect. Although fenofibrate-induced peroxisome proliferator-activated receptor alpha (PPARα) transcription activation has been shown to play an important role in the malignant progression of gliomas, the underlying mechanisms are poorly understood. METHODS: In this study, we analyzed TCGA database and found that there was a significant negative correlation between the long noncoding RNA (lncRNA) HOTAIR and PPARα. Then, we explored the molecular mechanism by which lncRNA HOTAIR regulates PPARα in cell lines in vitro and in a nude mouse glioma model in vivo and explored the effect of the combined application of HOTAIR knockdown and fenofibrate treatment on glioma invasion. RESULTS: For the first time, it was shown that after knockdown of the expression of HOTAIR in gliomas, the expression of PPARα was significantly upregulated, and the invasion and proliferation ability of gliomas were obviously inhibited. Then, glioma cells were treated with both the PPARα agonist fenofibrate and si-HOTAIR, and the results showed that the proliferation and invasion of glioma cells were significantly inhibited. CONCLUSIONS: Our results suggest that HOTAIR can negatively regulate the expression of PPARα and that the combination of fenofibrate and si-HOTAIR treatment can significantly inhibit the progression of gliomas. This introduces new ideas for the treatment of gliomas.

Combination LSD1 and HOTAIR-EZH2 inhibition disrupts cell cycle processes and induces apoptosis in glioblastoma cells.

Glioblastoma (GBM) is the most common primary central nervous system tumor and has a poor prognosis, with a median survival time of only 14 months from diagnosis. Abnormally expressed long noncoding RNAs (lncRNAs) are important epigenetic regulators of chromatin modification and gene expression regulation in tumors, including GBM. We previously showed that the lncRNA HOTAIR is related to the cell cycle progression and can be used as an independent predictor in GBM. Lysine-specific demethylase 1 (LSD1), binding to 3' domain of HOTAIR, specifically removes mono- and di-methyl marks from H3 lysine 4 (H3K4) and plays key roles during carcinogenesis. In this study, we combined a HOTAIR-EZH2 disrupting agent and an LSD1 inhibitor, AC1Q3QWB (AQB) and GSK-LSD1, respectively, to block the two functional domains of HOTAIR and potentially provide therapeutic benefit in the treatment of GBM. Using an Agilent Human ceRNA Microarray, we identified tumor suppressor genes upregulated by AQB and GSK-LSD1, followed by Chromatin immunoprecipitation (ChIP) assays to explore the epigenetic mechanisms of genes activation. Microarray analysis showed that AQB and GSK-LSD1 regulate cell cycle processes and induces apoptosis in GBM cell lines. Furthermore, we found that the combination of AQB and GSK-LSD1 showed a powerful effect of inhibiting cell cycle processes by targeting CDKN1A, whereas apoptosis promoting effects of combination therapy were mediated by BBC3 in vitro. ChIP assays revealed that GSK-LSD1 and AQB regulate P21 and PUMA, respectively via upregulating H3K4me2 and downregulating H3K27me3. Combination therapy with AQB and GSK-LSD1 on tumor malignancy in vitro and GBM patient-derived xenograft (PDX) models shows enhanced anti-tumor efficacy and appears to be a promising new strategy for GBM treatment through its effects on epigenetic regulation.

Enhanced photothermal signal detection by graphene oxide integrated long period fiber grating for on-site quantification of sodium copper chlorophyllin.

An enhanced photothermal signal detection method based on graphene oxide (GO) integrated long period fiber grating (LPFG) for on-site sodium copper chlorophyllin (SCC) quantification is proposed. SCC, as a porphyrin compound, can be photonically excited to induce a stronger photothermal effect. GO offers superior molecular adsorption and thermal conductivity properties; depositing it on the LPFG surface significantly improves the sensitivity and detection efficiency of the SCC photothermal signal, when irradiated with a 405 nm laser. The experimental results showed improved performance compared with those from uncoated LPFG, with a sensitivity of 0.0587 dB (mg L-1)-1 and a limit of detection (LOD) of 0.17 mg kg-1, which is also an order of magnitude lower than that of traditional high-performance liquid chromatography. The proposed method has potential applications in the fields of real-time food safety monitoring, environmental pollutant detection, and disease diagnosis.

Transparent HfO x -based memristor with robust flexibility and synapse characteristics by interfacial control of oxygen vacancies movement.

Hafnium oxides (HfO x ) based flexible memristors were fabricated on polyethylene naphtholate (PEN) substrates to simulate a variety of bio-synapse functions. By optimizing the manufacturing conditions of electrode and active films, it is proved that the TiN/HfO x /W/ITO/PEN bilayer device has robust flexibility and can still be modulated after 2000 times of bending. The memristor device exhibits better symmetrical and linear characteristics with excellent uniformity at lower programming power consumption (∼38 µW). In addition, the essential synaptic behaviors have further been achieved in the devices, including the transition from short-term plasticity to long-term plasticity and spike time-dependent plasticity. Through the analysis of I-V curves and XPS data, a switching mechanism based on HfO x /W interface boundary drift is constructed. It is revealed that the redox reaction caused by W intercalation can effectively regulate the content of oxygen vacancy in HfO x . At the same time, bias-induced interfacial reactions will regulate the movement of oxygen vacancies, which emulates bio-synapse functions and improves the electrical properties of the device.

Effectiveness of virtual simulation and jaw model for undergraduate periodontal teaching.

BACKGROUND: The current study explored the effect of virtual simulation and jaw model on development of preclinical periodontal skills in undergraduate students. The study also sought to explore effectiveness of VR in periodontal preclinical training and determine adequate performance mode in basic periodontal education to improve future preclinical training strategies. METHODS: Sixty volunteer sophomores and juniors from the stomatology department in Lanzhou university were enrolled to the current study. Participants were randomly assigned into four groups (each group, n = 15) including the traditional jaw model group (Group J) which was the control group, virtual reality group (Group V), virtual-jaw group (Group V-J), and jaw-virtual group (Group J-V). Participants received training on uniform basic periodontal knowledge before completing the first theoretical assessment. Participants further underwent a total 8 h of operation training and completed a second theoretical assessment. Performance of participants was evaluated using the supragingival scaling processes, and clinical operation scores were graded by a blinded professional using an established standard scoring system. RESULTS: The findings showed no significant difference in the first theoretical outcomes between the four groups (P > 0.05). The scores of the second theoretical assessment were significantly improved for the V-J and J-V groups (60.00 ± 4.47, 58.33 ± 4.35) compared with the scores of the first theoretical exam (49.67 ± 4.81, 48.00 ± 4.93, P < 0.05). The operation process scores of students in Group V-J and J-V (72.00 ± 5.92; 70.00 ± 3.05) were significantly higher compared with the scores in the other two groups (V: 61.67 ± 7.85; J: 60.67 ± 2.58). The scaling process performance of students in Group V-J and J-V (53.00 ± 3.05; 63.40 ± 4.39) was improved compared with that of students in the other two groups (V: 41.90 ± 5.23; J: 47.40 ± 4.31). CONCLUSION: The findings show that combination of virtual reality and jaw model during periodontal preclinical training increases students' grades and improves acquiring of professional skills. Findings from the current study indicate that the jaw model should be applied prior to virtual reality to ensure high efficacy.

Flexible Particle Focusing and Switching in Continuous Flow via Controllable Thermal Buoyancy Convection.

We present a novel approach that utilizes thermal buoyancy convection to achieve flexible particle focusing and switching in continuous flow of a microfluidic system. In this platform, three strip microheaters, A, B, and C, are symmetrically distributed at the bottom of microchannel, and they are isolated from the particle suspension by a thin glass slide. Continual transverse convection flow forms when the microheaters are energized by dc signals. The flow patterns are readily tuned by changing the energization strategies of the microheater array, leading to the modulation of the position of flow stagnation region. Accordingly, microparticles dispersed in fluids are rapidly focused to the flow stagnation region by the Stokes drag and thus form a continuous particle beam. The particle beam can also be switched to different lateral positions by adjusting the control voltages. This particle manipulation method is first demonstrated by respectively energizing these three microheaters and subsequently switching silica particles into different outlets. The lateral position of the particle beam then is flexibly controlled by simultaneously energizing microheaters A and B (or B and C) and adjusting the voltage applied on microheater A (or C). Furthermore, the versatility of this approach is proved by focusing and switching of microsized droplets, that is, oil-in-water and water-in-oil-in-water emulsion droplets. Finally, we use poly(ethylene glycol) diacrylate microgels, excellent reactant carriers, as an experimental sample and flexibly manipulate them in this microdevice, demonstrating this strategy's applicability for the cargo delivery. Therefore, this technique can be attractive for many particle preprocessing applications.

Tissue mechanics and expression of TROP2 in oral squamous cell carcinoma with varying differentiation.

BACKGROUND: Trophoblast cell surface antigen 2 (TROP2) is overexpressed in many squamous cell carcinomas and promotes tumor development and invasion. The association between TROP2 expression and occurrence and development of oral squamous cell carcinoma (OSCC) remains to be understood. METHODS: We investigated the role of TROP2 in OSCC patients using a combination of biophysical approaches. A total of 108 OSCC patient specimens with varying degrees of differentiation were subjected to hematoxylin and eosin staining, immunohistochemistry, Kaplan-Meier survival curve analysis, and atomic force microscopy to analyze TROP2 expression, morphology, and mechanical properties of OSCC tissues. RESULTS: TROP2 was overexpressed in 34% of poorly differentiated OSCC samples. High levels of TROP2 were associated with 10.2% survival rate lower than 45.4% and patient age (odds ratio [OR] = 0.437, P = 0.039, 95% confidence interval [CI, 0.198-0.966]), tumor size (OR = 13.148, P = 0.000, 95% CI [5.060-34.168]), and TNM stage (OR = 0.141, P = 0.000, 95% CI [0.082-0.244]). Average surface roughness of low, medium, and highly differentiated OSCC tissues were 448.9 ± 54.8, 792.7 ± 83.6, and 993.0 ± 104.3 nm, respectively. The Pearson coefficient revealed a negative association between tumor stiffness and TROP2 expression (r = - 0.84, P < 0.01). CONCLUSION: Overexpression of TROP2 negatively associated with patient survival, degree of tumor differentiation, and tissue mechanics. Taken together, our findings demonstrated that TROP2 may be an indicator of OSCC differentiation leading to the altered mechanical properties of OSCC tissues.

Low consumption two-terminal artificial synapse based on transfer-free single-crystal MoS2 memristor.

Both synaptic emulators and brain-like calculation demand an energy-efficient and bio-realistic device where two-dimensional materials have been proven as a promising competitor. Lateral memristors based on transfer-free single-crystal MoS2 with single layer grown by chemical vapor deposition (CVD) were fabricated. Here the MoS2 memristor successfully emulates typical biological synaptic behaviors including excitatory/inhibitory post-synaptic current (EPSC/IPSC), spike timing-dependent plasticity (STDP), spike rate-dependent plasticity (SRDP) and long-term plasticity (LTP). Moreover, an interesting multi-state LTP and a low consumption of 1.8 pJ after LTP process are achieved which is attributed to the high resistance of transfer-free single-crystal monolayer MoS2, representing a low value among previous MoS2 devices. The migration of Sulfur vacancies lead the conductance modulation by changing the Schottky barrier instead of forming a filament. Our work demonstrates that MoS2 memristors can more flexibly satisfy the demands of complex artificial synaptic/neuron applications.

Magnetic sensor based on serial-tilted-tapered optical fiber for weak-magnetic-field measurement.

An optical fiber magnetic field sensor based on serial-tilted-tapered fiber (STTF) integrated with magnetic fluid is proposed. The compact STTF structure consists of two closely tilted-tapered fibers with a length of approximately 836 µm, which results in stronger mode coupling. The transmission characteristics of the proposed sensor under different magnetic field intensities (MFIs) have been studied. The results show that the proposed structure has an outstanding response to MFI and that the highest sensitivity is 32.67 pm/Oe in wavelength and 0.0336 dB/Oe in transmission in the range of 0-75 Oe. The minimum resolution of the proposed sensor is up to 0.6734 Oe. These types of sensors have great potential application in weak magnetic field measurements due to their compact structure and good sensing performance.

Simultaneous measurement of the BOD concentration and temperature based on a tapered microfiber for water pollution monitoring.

An optical sensor that simultaneously measures the concentration of the biochemical oxygen demand (BOD) and temperature in water based on a tapered microfiber is proposed for environmental monitoring. The sensor is characterized by a strong evanescent field, which is more sensitive to liquids with a low refractive index and a low transmission loss. The results show that as the BOD concentration increases, the interference spectrum shifts toward longer wavelengths, the spectral loss decreases, and the sensitivities of the BOD are 12.17 nm/mg/mL and -2.387dB/mg/mL in the range of 0.25-1 mg/mL, which indicates the extent of the water pollution. The detection limit for the BOD concentration is as low as 0.0016 mg/mL. As the ambient temperature increases, the interference spectrum shifts toward shorter wavelengths, the spectral loss decreases, and the temperature sensitivities are -0.339nm/∘C and -0.031dB/∘C in the range of 30°C-60°C. The matrix method can be used to achieve the simultaneous measurement of the BOD concentration and environmental temperature because the spectral interference peaks have different responses to these two parameters. The sensor can not only be used for detecting water pollution in rivers, drinking water, and groundwater but can also be utilized for other types of environmental monitoring. This sensor has great potential to act as a basic sensing unit in fiber-optic sensor networks for multiparameter measurements and intelligent monitoring.

Virtual versus jaw simulation in Oral implant education: a randomized controlled trial.

BACKGROUND: This research aims to investigate the evaluation methods of teaching oral implant clinical courses and estimate the effectiveness of a virtual simulation platform. METHODS: Eighty second- and third-year undergraduates in Lanzhou University were recruited and randomized to either three experimental groups or one control group. The subjects undertook theoretical examinations to test their basic level of knowledge after training in similarly unified knowledge courses. Each student group then participated in an eight-hour operating training session. An operation test on pig mandible was conducted, followed by a second theoretical examination. The assessment consists of three distinct parts: a subjective operating score by a clinical senior teacher, an implant accuracy analysis in cone-beam computed tomography (angular, apical, and entrance deviation), and comparison of the two theoretical examinations. Finally, students completed a questionnaire gauging their understanding of the virtual simulation. RESULTS: There was no significant difference between the four groups in first theoretical examination (P > 0.05); the second theoretical scores of the V-J and J-V group (62.90 ± 3.70, 60.05 ± 2.73) were significantly higher than the first time (57.05 ± 3.92, P < 0.05), while no difference between the V (57.10 ± 3.66) and J (56.89 ± 2.67) groups was found. Thus, the combination of V-J was effective in improving students' theoretical scores. The V-J and J-V groups had higher scores on operation (73.98 ± 4.58, 71.85 ± 4.67) and showed better implant precision. CONCLUSION: Virtual simulation education, especially with a jaw simulation model, could improve students' implantology achievements and training. Currently study found that the V-J group may performed better than the J-V group in oral implant teaching.