High-accuracy heart rate detection using multispectral IPPG technology combined with a deep learning algorithm.

Image Photoplethysmography (IPPG) technology is a noncontact physiological parameter detection technology, which has been widely used in heart rate (HR) detection. However, traditional imaging devices still have issues such as narrower receiving spectral range and inferior motion detection performance. In this paper, we propose a HR detection method based on multi-spectral video. Our method combining multispectral imaging with IPPG technology provides more accurate physiological information. To realize real-time evaluation of HR directly from facial multispectral videos, we propose a new end-to-end neural network, namely IPPGResNet18. The IPPGResNet18 model was trained on the multispectral video dataset from which better results were achieved: MAE = 2.793, RMSE = 3.695, SD = 3.707, p = 0.304. The experimental results demonstrate a high accuracy of HR detection under motion state using this detection method. In respect of real-time monitoring of HR during movement, our method is obviously superior to the conventional technical solutions.

Tunable extraordinary optical transmission spectrum properties of long-wavelength infrared metamaterials.

Metamaterial filters represent an essential method for researching the miniaturization of infrared spectral detectors. To realize an 8-2 µm long-wave infrared tunable transmission spectral structure, an extraordinary optical transmission metamaterial model was designed based on the grating diffraction effect and surface plasmon polariton resonance theory. The model consisted of an Al grating array in the upper layer and a Ge substrate in the lower layer. We numerically simulated the effects of different structural parameters on the transmission spectra, such as grating height (h), grating width (w), grating distance (d), grating constant (p), and grating length (S 1), by utilizing the finite-difference time-domain method. Finally, we obtained the maximum transmittance of 81.52% in the 8-12 µm band range, with the corresponding structural parameters set to h=50n m, w=300n m, d=300n m, and S 1=48µm, respectively. After Lorentz fitting, a full width at half maximum of 0.94±0.01µm was achieved. In addition, the Ge substrate influence was taken into account for analyzing the model's extraordinary optical transmission performance. In particular, we first realized the continuous tuning performance at the transmission center wavelength (8-12 µm) of long-wave infrared within the substrate tuning thickness (D) range of 1.9-2.9 µm. The structure designed in this paper features tunability, broad spectral bandwidth, and miniaturization, which will provide a reference for the development of miniaturized long-wave infrared spectral filter devices.

High efficiency stimulated rotational Raman scattering of hydrogen pumped by 1064 nm.

Laser-induced breakdown (LIB) and the competition of other Raman processes are major reasons restricting photon conversion efficiency (PCE) of Raman lasers. In this work, 1064 nm was used as the pump source, and stimulated rotational Raman scattering of hydrogen was investigated. The configuration of zooming out and focusing pump beam was applied, and the dimension of the pump beam at the focus spot increased significantly; consequently, LIB was suppressed, and Raman PCE was improved dramatically. With the help of the Raman gas pressure optimization, vibrational Raman could be fully suppressed, and other competition Raman processes could be well controlled. The optimal PCEs of different rotational Raman lasers could be achieved under different conditions. The maximum PCE of the first rotational Stokes (RS1) was improved to 60.7%, and the maximum energy of RS1 reached 204.5 mJ. With the increment of hydrogen pressure, the maximum PCE of the second rotational Stokes (RS2) was improved to 28.2%, and the maximum energy of RS2 reached 123.9 mJ. Furthermore, a 2.1 µm Raman laser was also generated, the maximum PCE of 2.1 µm reached 44.8%, and its pulse energy reached 106.1 mJ.

Lead Chalcogenide Colloidal Quantum Dots for Infrared Photodetectors.

Infrared detection technology plays an important role in remote sensing, imaging, monitoring, and other fields. So far, most infrared photodetectors are based on InGaAs and HgCdTe materials, which are limited by high fabrication costs, complex production processes, and poor compatibility with silicon-based readout integrated circuits. This hinders the wider application of infrared detection technology. Therefore, reducing the cost of high-performance photodetectors is a research focus. Colloidal quantum dot photodetectors have the advantages of solution processing, low cost, and good compatibility with silicon-based substrates. In this paper, we summarize the recent development of infrared photodetectors based on mainstream lead chalcogenide colloidal quantum dots.

Maresin1 alleviates liver ischemia/reperfusion injury by reducing liver macrophage pyroptosis.

BACKGROUND: Cell pyroptosis has a strong proinflammatory effect, but it is unclear whether pyroptosis of liver macrophages exacerbates liver tissue damage during liver ischemia‒reperfusion (I/R) injury. Maresin1 (MaR1) has a strong anti-inflammatory effect, and whether it can suppress liver macrophage pyroptosis needs further study. METHODS: This study aimed to investigate whether MaR1 can alleviate liver I/R injury by inhibiting macrophage pyroptosis. The effects of MaR1 on cell pyroptosis and mitochondrial damage were studied by dividing cells into control, hypoxia/reoxygenation, and hypoxia/reoxygenation + MaR1 groups. Knocking out RORa was used to study the mechanism by which MaR1 exert its protective effects. Transcriptome analysis, qRT‒PCR and Western blotting were used to analyze gene expression. Untargeted metabolomics techniques were used to analyze metabolite profiles in mice. Flow cytometry was used to assess cell death and mitochondrial damage. RESULTS: We first found that MaR1 significantly reduced liver I/R injury. We observed that MaR1 decreased liver I/R injury by inhibiting liver macrophage pyroptosis. Then, we discovered that MaR1 promotes mitochondrial oxidative phosphorylation, increases the synthesis of ATP, reduces the generation of ROS, decreases the impairment of mitochondrial membrane potential and inhibits the opening of mitochondrial membrane permeability transition pores. MaR1 inhibits liver macrophage pyroptosis by protecting mitochondria. Finally, we found that MaR1 exerts mitochondrial protective effects through activation of its nuclear receptor RORa and the PI3K/AKT signaling pathway. CONCLUSIONS: During liver I/R injury, MaR1 can reduce liver macrophage pyroptosis by reducing mitochondrial damage, thereby reducing liver damage.

The effect of chronic alcohol exposure on spatial memory and BDNF-TrkB- PLCγ1 signaling in the hippocampus of male and female mice.

Alcohol is a commonly used drug worldwide, and abuse of alcohol has become a serious public health problem. Alcohol consumption over time can cause cognitive deficits and memory impairment, which is thought to be associated with changes in the hippocampus. Given previously known effects of brain-derived neurotrophic factor (BDNF) in regulating synaptic plasticity and learning and memory, we investigated the effect of chronic alcohol consumption on spatial memory impairment in both sexes and changes in BDNF signaling in the hippocampus. After 4 weeks of intermittent access to 20% alcohol, memory impairment in both male and female mice was evaluated using the Morris water maze and the expression of BDNF, TrkB, phosphorylation of PLCγ1 (p-PLCγ1) and PLCγ1 in the hippocampus was examined using Western blot. As expected, females spent longer escape latencies during the training phase, and both sexes spent shorter time in the target quadrant. Furthermore, after 4 weeks 20% alcohol exposure, we found significantly decreased expression levels of BDNF in the hippocampus of female mice but increased levels in male mice. TrkB and PLCγ1 expression showed no significant change in the hippocampus of both sexes. These findings suggest that chronic alcohol exposure may induce spatial memory impairment in both sexes and opposite changes in expression of BDNF and p-PLCγ1 in the hippocampus of males and females.

Progranulin inhibits fibrosis by interacting with and up-regulating DNAJC3 during mouse skin wound healing.

Scars place a heavy burden on both individuals and society. Our previous study found that reduction of progranulin (PGRN) promotes fibrogenesis in mouse skin wound healing. However, the underlying mechanisms have not been elucidated. Here, we report that PGRN overexpression decreases the expression of profibrotic genes alpha-smooth muscle actin (αSMA), serum response factor (SRF), and connective tissue growth factor (CTGF), thereby inhibiting skin fibrosis during wound repair. Bioinformatics analysis suggested that the heat shock protein (Hsp) 40 superfamily C3 (DNAJC3) is a potential downstream molecule of PGRN. Further experiments showed that PGRN interacts with and upregulates DNAJC3. Moreover, this antifibrotic effect was rescued by DNAJC3 knockdown. In summary, our study suggests that PGRN inhibits fibrosis by interacting with and upregulating DNAJC3 during wound healing in mouse skin. Our study provides a mechanistic explanation of the effect of PGRN on fibrogenesis in skin wound healing.

Stimulated vibrational-rotational Raman scattering of hydrogen pumped at a 1064-nm laser.

A ∼2.1-µm laser is within an atmospheric transmission window and can be used in remote sensing. In this work, a 1064-nm laser was used as the pump source, pressurized hydrogen was used as the Raman active medium, and a dual-wavelength ∼2.1-µm Raman laser was generated. The 2147-nm laser was generated by a combination processes of stimulated vibrational Raman scattering and stimulated rotational Raman scattering, while a 2132-nm laser was generated by stimulated S-branch vibrational Raman scattering. Optimizing experimental conditions yielded a maximum pulse energy of 76.1 mJ, a peak power of ∼9.2M W, and a photon conversion efficiency of 29.8%.

Super diffraction limit spectral imaging detection and material type identification of distant space objects.

The image information of distant objects shows a diffuse speckle pattern due to diffraction limit, non-uniform scattering, etc., which is difficult to achieve object discrimination. In this study, we have developed a staring spectral video imaging system mounted on a ground-based telescope observation platform to detect the high orbit space objects and gain their spectral images for six groups of GEO targets. The speckle remains basically the same characteristic as the projection structure of the object due to "the balloon inflation phenomenon of near parallel light during long-distance atmospheric transmission" under the premise of considering the bi-directional reflection distribution function (BRDF), Rayleigh scattering theory, and the memory effect. Based on this phenomenon, a mathematical model of remote target scattering spectrum imaging is established where the speckle can be treated as both a global speckle and speckle combination of texture blocks caused by various components of the target. The radial basis function (RBF) neural network is separately used to invert the global speckle and the speckle combination of the texture blocks on account of the typical target material database. The results show that the target materials are of relatively fewer kinds in the global inversion with only including gallium arsenide panel (GaAs) and carbon fiber (CF), for which the highest goodness of curve fitting is only 77.97. An improved algorithm makes their goodness of fit reach 90.29 and 93.33, respectively, in view of one conjecture that the target surface contains unknown materials. The spectral inversion result of the texture blocks shows that the types of materials in each target texture block increase significantly, and that the area ratio of different materials inverted in the block is different from each other. It is further confirmed that the speckle image contains the overall projection structure of distant target and the spectral image projection of each component is relatively fixed, which is the result of the comprehensive action of various mechanisms of ultra-long-haul atmospheric transmission and optical system focusing imaging after BRDF spectral scattering. The spectral image fine inversion is expected to restore the clear structure of the target. This discovery provides important support for the remote imaging and identification of distant and ultra-diffractive targets.

Research on NCFCP compact broadband NIR detector imaging and energy transfer function.

Nonlinear crystal frequency conversion imaging with direct detection by silicon-based detectors is an effective way to break through the limitations for existing near-infrared (NIR) detectors with expensive cost and high noise. In this paper, a broadband NIR detector imaging scheme based on the principle of nonlinear crystal frequency conversion (NCFCP) was proposed. A thin film of nonlinear crystal frequency conversion material (NCFCM) combined with a silicon-based detector was used to form a broadband NIR detector. The theoretically investigated energy transfer function was used as a guidance for experiment. Meanwhile, the relationship between the imaging effect and the energy transfer of the NCFCP-based compact broadband NIR detector in the NIR band was measured experimentally. The accuracy of the theoretical study had been verified by the measured transfer results.

Enhancement of the frequency conversion film imaging effect based on a cascade material fusion method.

Frequency conversion imaging technology can provide an effective way for infrared detection against the limitations of conventional infrared detectors, such as expense and cooling requirements, but the converted luminescence intensity of frequency conversion materials limits the application of this technology. In this paper, a cascade material (CM) fusion method is proposed to improve the conversion luminous intensity and thus enhance the frequency conversion imaging effect at 1550 nm near infrared (NIR) excitation. First, we derived from the energy level transition mechanism of CM that the CM fusion method can achieve three excitations of substrate materials (SMs). It can improve the conversion luminescence intensity of SM in CM. Then, we experimentally prepared CM and SM films and simultaneously measured the frequency conversion imaging effect of the two films at 1550 nm NIR excitation. It was found that the weight ratio of doped material (DM) to SM affects the imaging enhancement of CM films. Therefore, we compared the imaging grayscale value intensity of CM films with different weight ratios under the same detection conditions. Finally, it was concluded that the best enhancement of frequency conversion imaging was achieved with a DM to SM weight ratio of 0.25 for this mechanism. The enhancement was about 3.11 times compared to SM films.

MiR-574-5p promotes cell proliferation by negatively regulating small C-terminal domain phosphatase 1 in esophageal squamous cell carcinoma.

Objectives: Esophageal cancer is one of the most common cancers with high incidence and mortality rates, especially in China. MicroRNA (miRNA) can be used as a prognostic marker for various human cancers. This study aims to detect suitable miRNA markers for esophageal squamous cell carcinoma (ESCC). Materials and Methods: Our previous gene expression data of ESCC cells and the data from GSE43732 and GSE112840 were analyzed. The expression of miR-574-5p in ESCC patients and controls was analyzed by real-time quantitative PCR. The effect of miR-574-5p on proliferation was detected by real-time cell analysis (RTCA) and EdU proliferation assay after cell transfections. The target gene small C-terminal domain phosphatase 1 (CTDSP1) of miR-574-5p was validated by luciferase reporter assay and western blotting. Results: In the current study, the bioinformatics analysis found miR-574-5p up-regulated in ESCC. The qPCR assay of 26 ESCC and 13 adjacent/ normal tissues confirmed these results. We further demonstrated that miR-574-5p overexpression promoted cell proliferation. Then the dual-luciferase reporter assay and the rescue experiment suggested that CTDSP1 was a direct target of miR-574-5p. Conclusion: MiR-574-5p played an oncological role in ESCC by interacting and negatively regulating CTDSP1. These results provided a deeper understanding of the effect of miR-574-5p on ESCC.

Safety and immunogenicity of inactivated SARS-CoV-2 vaccines in people with gastrointestinal cancer.

OBJECTIVES: This study aimed to evaluate the safety and immunogenicity of inactivated COVID-19 vaccines in patients with gastrointestinal cancer (GI) cancer. The role of memory B cells (MBCs) in the humoral response to COVID-19 vaccination was also investigated. METHODS: In this prospective observational study, GI cancer patients and healthy individuals who had received 2 doses of inactivated COVID-19 vaccines were included. The data regarding adverse effects, serum anti-receptor binding domain (RBD)-IgG, neutralizing antibodies (NAbs), and frequencies of MBCs were collected prospectively. RESULTS: The inactivated COVID-19 vaccines were safe and well tolerated. Serum anti-RBG-IgG and NAbs were lower for cancer patients. Old age, high ASA score, and receiving active chemotherapy were risk factors for lower antibody titers. The frequencies of activated and resting MBCs decreased in (17.45% vs 38.11%, P = 0.002; 16.98% vs 34.13%, P = 0.023), while the frequencies of intermediate and atypical MBCs increased in cancer patients (40.06% vs 19.87%, P = 0.010; 25.47% vs 16.61%, P = 0.025). The serum antibody titer decreased gradually during follow-up but increased when a booster vaccine was given. CONCLUSION: The inactivated COVID-19 vaccines were well tolerated in patients with GI cancer but with lower immunogenicity. The subpopulations of MBCs were disordered in cancer patients, and a booster vaccine may be prioritized for them.

The complete mitochondrial genome of Sarcophila rasnitzyni (Diptera: Sarcophagidae).

Sarcophila rasnitzyni Rohdendorf and Verves, 1985 (Diptera: Sarcophagidae) is of potential significance in medicine and epidemiology. In this study, we present the mitochondrial genome of S. rasnitzyni. The full length of the mitochondrial genome is 15,321 bp (GenBank accession no. MW592359), and 13 protein-coding genes (PCGs), two ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs), and a non-coding control region were identified. Nucleotide composition is A 38.0%, G 9.9%, C 14.9%, T 37.2%, respectively. It reveals a strong A + T bias (75.2%). Phylogenetic analysis indicates that the species-level relationship between S. rasnitzyni and S. mongolica closely clusters together, and separates clearly from the rest of species. This study provides important genetic data for further enriching our understanding of phylogenetic relationship of sarcophagids species.

Phase transition-induced changes in the Raman properties of DMSO/benzene binary systems.

The Raman spectra of dimethylsulfoxide (DMSO)/benzene binary mixtures were studied by decreasing the temperature from 333 K to 263 K with the aim to reveal the molecular interaction properties during phase transition. The intensity of the Raman band for benzene at 992 cm-1 showed an increasing trend in the liquid and solid phases, while it exhibited a highly decreasing trend during the liquid-solid phase transition. The potential energy was calculated to study the effect of intermolecular interaction distance between DMSO and benzene on Raman intensity. The observations indicated that the blueshift of the low-frequency bands of DMSO was significantly different from the redshift of its high-frequency bands. The hydrogen bond generated between DMSO and benzene was well formed in the binary systems. This interaction inducing an enhanced hydrogen bond between the binary systems and attenuated C-H bonds led to opposite Raman shift variations with decreasing temperature. The Raman bands of DMSO at 1425 cm-1, 2899 cm-1, and 2992 cm-1 each split into two peaks after phase transition. The splitting of the Raman bands of DMSO at 1417 cm-1, 2895 cm-1, and 2982 cm-1 cropped up as the temperature dropped to the transformation point of 288 K. This is attributed to the phase transition-induced latent def.(C7) atomic vibrations corresponding to the individual methyl groups of DMSO. The implications of these analyses are expected to be helpful to understand the effect of phase transition on the Raman properties of binary solutions.

An enzyme-responsive Gp1a-hydrogel for skin wound healing.

Faster recovery and fewer scars are ideal wound healing. We have demonstrated that the cannabinoid receptor 2 (CB2) agonist Gp1a is beneficial to skin wound healing, which inhibits inflammation and fibrogenesis while promoting re-epithelialization. However, the systemic administration is imprecise and overqualified for a local skin wound. Herein, we prepared Gp1a-gel using triglycerol monostearate (Tm) hydrogel and detected whether the Gp1a-gel worked effectively on mouse skin excision wounds. The results showed that Gp1a-gel might sustainably increase the CB2 for at least 8 days. It decreased inflammation and fibrogenesis while promoting wound enclosure and re-epithelialization. These results suggested Gp1a-gel may utilize as a potential formulation strategy to treat the skin wound.

Inversion of spectral information obtained during hypersonic impact.

A large number of space activities are generating a high amount of undesirable space debris, which causes inevitable damage to spacecraft and satellites. Moreover, the damage assessment of ultrahigh-speed debris is a challenging task that requires both theoretical and ground-level experimental simulations. One should note that the location and damage degree can be preliminarily determined by measuring the impact flash spectrum, which provides basic data for damage assessment. Herein, the radiation spectrum of an ultrahigh-speed collision between plastic projectile and aluminum target is measured by using spectroscopic technology. The surface temperature of the colliding material, electron temperature, and electron density in the plasma are simultaneously retrieved by using a single-frame spectrum. The single-frame spectrum is separated into a continuous spectrum and a line spectrum by using continuous thermal radiation spectrum inversion material interface temperature and line spectrum inversion electron temperature and electron density in the plasma.

[Optimization of medical educational objectives by improving summative assessment system].

Summative assessment plays a decisive role in the educational assessment system, which is a yardstick to measure the cultivating goal of higher education. The rapid progress of modern society has put forward higher standard for higher medical education. Traditional summative assessment system with single dimension that focuses on evaluating the student's learning outcome via a standardized examination cannot meet the higher requirements for undergraduate medical education. We have improved the summative assessment system by optimizing the assessment content, criteria and method, as well as teachers' assessment skills and students' evaluation. The reform greatly increases the teaching quality and learning effect in our university.

Protective role of histone deacetylase 4 from ultraviolet radiation-induced DNA lesions.

Ultraviolet B (UVB) exposure is a core factor that leads to skin disease or carcinogenesis through the insufficient repair of DNA lesions. UVB-induced DNA lesions are mainly removed by the nucleotide excision repair (NER) mechanism. The expression of histone deacetylase 4 (HDAC4) is altered in the skin upon UVB exposure, indicating its possible implication in UVB-induced DNA lesions repair. Here, we investigated the role of HDAC4 in the NER removal of the main classes of UVB-induced DNA lesions consisting of cyclobutane pyrimidine dimers and pyrimidine (6-4) pyrimidone photoproducts (6-4PPs). We found that UVB irradiation increased HDAC4 expression at both the mRNA and protein levels. HDAC4 interacted with NER factor XPC, which played an important role in effectively removing the UVB-induced DNA lesions. This study provides an understanding of the HDAC4 function in DNA repair, which will allow the development of efficient strategies to protect the skin from UVR-induced diseases.