Photoswitchable Azobispyrazole Crystals Achieving Near-Quantitative Crystalline-State Bidirectional E ⇆ Z Conversions.

Azo molecules, being extensively studied as photoswitches, have demonstrated versatile photoswitching performance and applications in solution-phase systems. However, the dense molecular packing and insufficient conformational freedom in the solid/crystalline state typically pose a challenge to their E ⇆ Z isomerization. This study presents a breakthrough in solid-state azo chemistry, where the investigated azobispyrazole molecules are capable of achieving high E → Z photoconversion, ranging from 85% to nearly quantitative (96%), and quantitative Z → E photoswitching in their crystalline states. To the best of our knowledge, azobispyrazoles are the first photoswitchable azo crystals that achieve high-yield bidirectional conversions, particularly the challenging thermodynamically stable-to-metastable E → Z transformation. Crystallographic and computational analyses provide in-depth insights into the photoswitching mechanism and propose that locally distributed free spaces and weak intermolecular interactions within the crystal structures are key factors contributing to the crystalline-state conversion. This work opens up new avenues for the development of promising photoswitchable azo crystals and also underscores the potential application of azobispyrazole crystals as light-responsive materials.

Type-II IFN inhibits SARS-CoV-2 replication in human lung epithelial cells and ex vivo human lung tissues through indoleamine 2,3-dioxygenase-mediated pathways.

Interferons (IFNs) are critical for immune defense against pathogens. While type-I and -III IFNs have been reported to inhibit SARS-CoV-2 replication, the antiviral effect and mechanism of type-II IFN against SARS-CoV-2 remain largely unknown. Here, we evaluate the antiviral activity of type-II IFN (IFNγ) using human lung epithelial cells (Calu3) and ex vivo human lung tissues. In this study, we found that IFNγ suppresses SARS-CoV-2 replication in both Calu3 cells and ex vivo human lung tissues. Moreover, IFNγ treatment does not significantly modulate the expression of SARS-CoV-2 entry-related factors and induces a similar level of pro-inflammatory response in human lung tissues when compared with IFNß treatment. Mechanistically, we show that overexpression of indoleamine 2,3-dioxygenase 1 (IDO1), which is most profoundly induced by IFNγ, substantially restricts the replication of ancestral SARS-CoV-2 and the Alpha and Delta variants. Meanwhile, loss-of-function study reveals that IDO1 knockdown restores SARS-CoV-2 replication restricted by IFNγ in Calu3 cells. We further found that the treatment of l-tryptophan, a substrate of IDO1, partially rescues the IFNγ-mediated inhibitory effect on SARS-CoV-2 replication in both Calu3 cells and ex vivo human lung tissues. Collectively, these results suggest that type-II IFN potently inhibits SARS-CoV-2 replication through IDO1-mediated antiviral response.

Utility of covered stents as a bypass for the treatment of central venous occlusion: a case report.

BACKGROUND: Central venous occlusion (CVO) is difficult to treat with percutaneous transluminal angioplasty because the guidewire cannot pass through the occluded segments. In this study, we devised a new method for establishing an extra-anatomic bypass between the right subclavian vein and the superior vena cava via a covered stent to treat whole-segment occlusion of the right brachiocephalic vein (BCV) with calcification. CASE PRESENTATION: We present the case of a 58-year-old female patient who complained of right arm swelling present for 1.5 years. Twelve years prior, the patient began hemodialysis because chronic glomerulonephritis had progressed to end-stage renal disease. During the first 3 years, a right internal jugular vein (IJV)-tunneled cuffed catheter was used as the dialysis access, and the catheter was replaced once. A left arteriovenous fistula (AVF) was subsequently established. Owing to occlusion of the left AVF, a new fistula was established on the right upper extremity 1.5 years prior to this visit. Angiography of the right upper extremity revealed complete occlusion of the right BCV and IJV with calcification. Because of the failure to pass the guidewire across the lesion, we established an extra-anatomic bypass between the right subclavian vein and the superior vena cava with a covered stent. Angiography confirmed the patency of whole vascular access system. After 3 months of follow-up, the patient's AVF function and the bypass patency were satisfactory. CONCLUSIONS: As a new alternative for the treatment of long, angled CVO with or without calcification, a covered stent can be used to establish an extravascular bypass between central veins.

Urbanization and weather dynamics co-dominated the spatial-temporal variation in pCO2 and CO2 fluxes in small montanic rivers draining diverse landscapes.

Rivers have been widely reported as important CO2 emitters to the atmosphere. Rapid urbanization has a profound impact on the carbon biogeochemical cycle of rivers, leading to enhanced riverine CO2 evasions. However, it is still unclear whether the spatial-temporal patterns of CO2 emissions in the rivers draining diverse landscapes dominated by urbanization were stable, especially in mountainous areas. This study carried out a two-year investigation of water environmental hydrochemistry in three small mountainous rivers draining urban, suburban and rural landscapes in southwestern China, and CO2 partial pressure (pCO2) and fluxes (fCO2) in surface water were measured using headspace equilibrium method and classical thin boundary layer model. The average pCO2 and fCO2 in the highly urbanized river were of 4783.6 µatm and 700.0 mmol m-2 d-1, conspicuously higher than those in the rural river (1525.9 µatm and 123.2 mmol m-2 d-1), and the suburban river presented a moderate level (3114.2 µatm and 261.2 mmol m-2 d-1). It provided even clearer evidence that watershed urbanization could remarkably enhance riverine CO2 emissions. More importantly, the three rivers presented different longitudinal variations in pCO2, implying diversified spatial patterns of riverine CO2 emissions as a result of urbanization. The urban land can explain 49.6-69.1% of the total spatial variation in pCO2 at the reach scale, indicating that urban land distribution indirectly dominated the longitudinal pattern of riverine pCO2 and fCO2. pCO2 and fCO2 in the three rivers showed similar temporal variability with higher warm-rainy seasons and lower dry seasons, which are significantly controlled by weather dynamics, including monthly temperature and precipitation, but seem to be impervious to watershed urbanization. High temperature-stimulated microorganisms metabolism and riched-CO2 runoff input lead much higher pCO2 in warm-rainy seasons. However, it showed more sensitivity of pCO2 to monthly weather dynamics in urbanized rivers than that in rural rivers, and warm-rainy seasons showed hot moments of CO2 evasion for urban rivers. TOC, DOC, TN, pH and DO were the main controls on pCO2 in the urban and suburban rivers, while only pH and DO were connected with pCO2 in the rural rivers. This indicated differential controls and regulatory processes of pCO2 in the rivers draining diverse landscapes. Furthermore, it suggested that pCO2 calculated by the pH-total alkalinity method would obviously overestimate pCO2 in urban polluted rivers due to the inevitable influence of non-carbonate alkalinity, and thus, a relatively conservative headspace method should be recommended. We highlighted that urbanization and weather dynamics co-dominated the multiformity and uncertainty in spatial-temporal patterns of riverine CO2 evasions, which should be considered when modeling CO2 dynamics in urbanized rivers.

[Research Progress of Transcatheter Tricuspid Regurgitation Repair Device].

The tricuspid valve has been nicknamed the "forgotten valve" and is often neglected by clinicians. However, tricuspid regurgitation is a common clinical heart valve disease. With the continuous development of transcatheter interventional medical device technology, the treatment of tricuspid regurgitation has gradually attracted attention, and more and more companies are developing interventional medical devices for treating this disease. This review will provide an overview of the current research progress on transcatheter therapy for tricuspid regurgitation repair devices at home and abroad, including the design principles, operational steps, clinical outcomes, and the advantages and disadvantages of these devices.

Microcystins-Loaded Aged Nanoplastics Provoke a Metabolic Shift in Human Liver Cells.

Studies concerning the toxicity of pollutant-loaded nanoplastics (NPs) toward humans are still in their infancy. Here, we evaluated the adsorption of microcystins (MCs) by pristine and aged polystyrene nanoplastics (PSNPs), prepared MCs-loaded aged PSNPS (1, 5, 10, 15, and 19 µg/mg), and systematically mapped the key molecular changes induced by aged and MCs-loaded PSNPs to human hepatoblastoma (HepG2) cells. According to the results, MC-LR adsorption is increased 2.64-fold by aging, and PSNP accumulation is detected in HepG2 cells. The cytotoxicity of the MC-LR-loaded aged PSNPs showed a positive relationship with the MC-LR amount, as the cell viability in the 19 µg/mg loading treatment (aPS-MC19) was 10.84% lower than aged PSNPs; meanwhile, more severe oxidative damage was observed. Primary approaches involved stressing the endoplasmic reticulum and reducing protein synthesis that the aged PSNPs posed for HepG2 cells, while the aggravated cytotoxicity in aPS-MC19 treatment was a combined result of the metabolic energy disorder, oxidative damage, endoplasmic reticulum stress, and downregulation of the MC-LR target protein. Our results confirm that the aged PSNPs could bring more MC-LR into the HepG2 cells, significantly interfere with biological processes, and provide new insight into deciphering the risk of NPs to humans.

Controlling internal nutrients loading at low temperature using oxygen-loading zeolite and submerged macrophytes enhances environmental resilience to subsequent high temperature.

Nutrients releasing from anoxic sediment can be enhanced in summer because the dissolved oxygen (DO) consumption, nitrogen (N) and phosphorus (P) migration are susceptible to temperature. Herein, we proposed a method to hinder the aquatic environmental deterioration in warm seasons through consecutive application of oxygen- and lanthanum-modified zeolite (LOZ) and submerged macrophytes (V. natans) at low temperature scenario (5 °C, with depleted DO in water), and the effect was examined with drastic increasing the ambient temperature to 30 °C. The investigation was conducted in a microcosm scale including sediment cores (with a diameter of 11 cm, height of 10 cm) and overlying water (with depth of 35 cm). During the 60 days experiment, application of LOZ at 5 °C facilitated slower releasing and diffusion of oxygen from LOZ and the growth of V. natans. Thereby, when the temperature was increased to 30 °C and maintained for 35 days, the DO reached 10.01 mg/L, and the release of P and N from the sediment was reduced by 86% and 92%, respectively. This was achieved from the joint efforts of adsorption, biological conversion, chemical inactivation, and assimilation. Also, the LOZ inhibited 80% N2O, 75% CH4, and 70% CO2 emissions primary by promoting V. natans growth and reshaping microbiota. Meanwhile, the colonization of V. natans benefited the sustainable improvement in the water quality. Our results addressed the time that the remediation of anoxic sediment can be applied.

Thiazolylazopyrazoles as Nonsymmetric Bis-Heteroaryl Azo Switches: High-Yield Visible-Light Photoisomerization and Increased Z-Isomer Stability by o-Carbonylation.

Following the progress on mono-heteroaryl azo switches (Het-N=N-Ph), a few bis-heteroaryl azo switches (Het-N=N-Het) have been studied recently, whereas the nonsymmetric bis-heteroaryl ones (Het1 -N=N-Het2 ) that can combine the respective merits of each heterocycle, have received little attention. Here we report thiazolylazopyrazoles as nonsymmetric bis-heteroaryl azo switches that combine the visible-light switching character of the thiazole ring and the ease of o-substitution of the pyrazole ring. Thiazolylazopyrazoles can achieve (near-)quantitative visible-light isomerization in both directions and long Z-isomer thermal half-lives of several days. In contrast to the drastically destabilizing effect of o-methylation, o-carbonylation of the pyrazole ring can remarkably stabilize Z isomers by inducing attractive intramolecular interactions (dispersion, C-H⋅⋅⋅N bond, and lone-pair⋅⋅⋅π interaction). Our work highlights the importance of the rational combination of two heterocycles and suitable structural substitution in developing bis-heteroaryl azo switches.

Hypoxia-inducible factor protects against acute kidney injury via the Wnt/ß-catenin signaling pathway.

Promoting adaptive repair in acute kidney injury (AKI) is an effective strategy to prevent the progression from AKI to chronic kidney disease. However, the mechanisms involved in renal repair after AKI remain unclear. In this study, we investigated the role of hypoxia-inducible factor (HIF), an important regulator of ischemic and hypoxic injury, in AKI during the repair phase. We established mouse models of ischemia-reperfusion injury-induced AKI with adaptive repair or maladaptive repair. We found that after injury, activation of HIF in the adaptive repair group was rapid, whereas in the maladaptive repair group HIF activation was relatively delayed, and its expression was significantly lower than that in the adaptive repair group during the early repair phase. To further investigate the mechanism of HIF, we regulated the expression of HIF-1α and HIF-2α in HK-2 cells and EA.hy926 cells, respectively. Silencing HIF expression reduced proliferation and increased apoptosis in cells injured by hypoxia/reoxygenation. Self-healing ability was further reduced due to the downregulation of HIF. Moreover, HIF overexpression had the opposite effect. HIF increased the expression of ß-catenin and its downstream target genes. Activation of Wnt/ß-catenin by the small-molecule activator SKL2001 mitigated the damaging effect of HIF knockdown, whereas blockade of ß-catenin with the inhibitor IWR-1-endo reduced the protective effects of HIF. In conclusion, HIF, which is highly expressed in the early stage after AKI, promotes renal repair by interacting with the Wnt/ß-catenin signaling pathway.NEW & NOTEWORTHY We investigated the role of hypoxia-inducible factor (HIF) in acute kidney injury in vivo and in vitro. Expression of HIF in the adaptive repair group was more rapid and sufficient than that in the maladaptive repair group during the early repair phase. HK-2 and EA.hy926 cells treated with hypoxia/reoxygenation were used to elucidate the cross talk between HIF and the Wnt/ß-catenin signaling pathway by which HIF played a renoprotective role in acute kidney injury.

Fast physical random bit generation using a millimeter-wave white noise source.

A broadband millimeter-wave (MMW) white noise signal generated by optical heterodyning of two Fabry-Perot laser diodes (FP-LDs) subject to optical feedback is demonstrated and employed for fast physical random bit generation with a simple least significant bits (LSBs) retaining method. Firstly, under suitable feedback conditions, two external-cavity feedback FP-LDs can be easily driven into chaotic states. In this process, the optical spectra of multi-longitudinal modes are significantly broadened. Then, two spectral broadening multi-longitudinal chaotic signals are mixed and converted into an MMW white noise signal through the heterodyne beating technique combined with a fast photodetector. With such an approach, a high dimensional broadband chaos with perfect characteristics of MMW white noise (3-dB bandwidth beyond 50 GHz without any time-delay signature) is experimentally achieved. Finally, taking the generated MMW white noise as the entropy source, 640 Gb/s physical random bit generation is realized by directly selecting 4-LSBs at 160 GS/s sampling rate after an 8-bit analog-digital-convertor.

(Hetero)arylazo-1,2,3-triazoles: "Clicked" Photoswitches for Versatile Functionalization and Electronic Decoupling.

The development of light-responsive chemical systems often relies on the rational design and suitable incorporation of molecular photoswitches such as azobenzenes. Linking a photoswitch core with another π-conjugated molecular entity may give rise to intramolecular electronic coupling, which can dramatically impair the photoswitch function. Decoupling strategies have been developed based on additionally inserting a linker that can disrupt the through-bond electronic communication. Here we show that 1,2,3-triazole-a commonly used decoupling spacer-can be directly merged into the azoswitch core to construct a class of "self-decoupling" azoswitches called (hetero)arylazo-1,2,3-triazoles. Such azotriazole photoswitches are easily accessed and modularly functionalized by click chemistry. Their photoswitch property can be optimized by rational design of the substituent groups or heteroaryl rings, allowing (near-)quantitative E⇆Z photoisomerization yields and tunable Z-isomer thermal half-lives from days to years. Combined experimental and theoretical results demonstrate that the electronic structure of the photoswitch core is not substantially affected by various substituents attached to the 1,2,3-triazole unit, benefiting from its cross-conjugated nature. The combination of clickable synthesis, tunable photoswitch property, and self-decoupling ability makes (hetero)arylazo-1,2,3-triazoles intriguing molecular tools in developing photoresponsive systems with desired performance.

Azobispyrazole Family as Photoswitches Combining (Near-) Quantitative Bidirectional Isomerization and Widely Tunable Thermal Half-Lives from Hours to Years*.

Azobenzenes are classical molecular photoswitches that have been widely used. In recent endeavors of molecular design, replacing one or both phenyl rings with heteroaromatic rings has emerged as a strategy to expand molecular diversity and access improved photoswitching properties. Many mono-heteroaryl azo molecules with unique structures and/or properties have been developed, but the potential of bis-heteroaryl architectures is far from fully exploited. We report a family of azobispyrazoles, which combine (near-)quantitative bidirectional photoconversion and widely tunable Z-isomer thermal half-lives from hours to years. The two five-membered rings remarkably weaken the intramolecular steric hindrance, providing new possibilities for engineering the geometric and electronic structure of azo photoswitches. Azobispyrazoles generally exhibit twisted Z-isomers that facilitate complete Z→E photoisomerization, and their thermal stability can be broadly adjusted regardless of the twisted shape, overcoming the conflict between photoconversion (favored by the twisted shape) and Z-isomer stability (favored by the orthogonal shape) encountered by mono-heteroaryl azo switches.

Photochemical Phase Transitions Enable Coharvesting of Photon Energy and Ambient Heat for Energetic Molecular Solar Thermal Batteries That Upgrade Thermal Energy.

Discovering physicochemical principles for simultaneous harvesting of multiform energy from the environment will advance current sustainable energy technologies. Here we explore photochemical phase transitions-a photochemistry-thermophysics coupled regime-for coharvesting of solar and thermal energy. In particular, we show that photon energy and ambient heat can be stored together and released on demand as high-temperature heat, enabled by room-temperature photochemical crystal↔liquid transitions of engineered molecular photoswitches. Integrating the two forms of energy in single-component molecular materials is capable of providing energy capacity beyond that of traditional solar or thermal energy storage systems based solely on molecular photoisomerization or phase change, respectively. Significantly, the ambient heat that is harvested during photochemical melting into liquid of the low-melting-point, metastable isomer can be released as high-temperature heat by recrystallization of the high-melting-point, parent isomer. This reveals that photon energy drives the upgrading of thermal energy in such a hybrid energy system. Rationally designed small-molecule azo switches achieve high gravimetric energy densities of 0.3-0.4 MJ/kg with long-term storage stability. Rechargeable solar thermal battery devices are fabricated, which upon light triggering provide gravimetric power density of about 2.7 kW/kg and temperature increases of >20 °C in ambient environment. We further show their use as deicing coatings. Our work demonstrates a new concept of energy utilization-combining solar energy and low-grade heat into higher-grade heat-which unlocks the possibility of developing sustainable energy systems powered by a combination of natural sunlight and ambient heat.

High-energy, tunable, long-wave mid-infrared optical parametric oscillator based on BaGa4Se7 crystal.

A high-energy, tunable, long-wave mid-infrared optical parametric oscillator (OPO) based on the BaGa4Se7 crystal was demonstrated in this Letter with 1064 nm laser pumping. The mid-infrared OPO was designed as a double-pass single resonant oscillator (DP-SRO) to reduce the threshold and improve the outputs. Further optimization on the cavity length was theoretically and experimentally studied. With a short cavity length of 30 mm, the output energy of over 1 mJ/pulse at 11 µm was obtained with the pump energy of 39.5 mJ/pulse. In addition, a wide tuning range of 8-14 µm was experimentally achieved by rotating the BaGa4Se7 crystal.

Injection pulse-seeded terahertz-wave parametric generator with gain enhancement in wide frequency range.

An injection pulse-seeded terahertz-wave parametric generator (ips-TPG) has been demonstrated with gain enhancement in wide tuning range. Theoretical analysis denotes that the compensation of initial Stokes energy is favorable to the THz gain enhancement in wide frequency range, which is attributed to the improvement on interaction of stimulated polariton scattering (SPS) and difference frequency generation (DFG) processes. In the experiment, the THz frequency tuning range from 1.04 THz to 5.15 THz was achieved based on near-stoichiometric LiNbO3 (SLN) crystal. Compared with the traditional terahertz parametric oscillator (TPO) under the same experimental conditions, a significant enhancement of THz output energy was occurred in high frequency range. As the THz frequency increased from 1.9 THz to 3.6 THz, the enhancement ratios from 1.6 times to 34.7 times were obtained. Besides, the 3dB bandwidth of ips-TPG was measured to be 2.1 THz, which was about 2.6 times that of SLN-TPO. This THz parametric source with a relative flat gain in wide frequency range is suitable to a variety of practical applications.

High energy and tunable mid-infrared source based on BaGa4Se7 crystal by single-pass difference-frequency generation.

A high-energy and tunable mid-infrared source based on BaGa4Se7 crystal was demonstrated by single-pass difference-frequency generation (DFG). Orthogonally polarized wave at 1064 nm (λ1) and tunable idler wave (λ2) generated by KTP-OPO, which could be tuned in the wavelength range of 1360-1600 nm, were used as the DFG dual-wavelength pump. The pump parameters including total pump energy and energy ratio were studied. Maximum pulse energy of 5.72 mJ at 3.58 µm was obtained at the dual-wavelength pump energy of 58.4 mJ/pulse. The wavelength tuning range was 3.36-4.27 µm with a flat tunability. Moreover, a saturation phenomenon of DFG output was observed and experimentally inferred to be related to the input energy of λ2 in the BaGa4Se7 crystal.

Tunable dual-color terahertz wave parametric oscillator based on KTP crystal.

A tunable dual-color KTP terahertz (THz) wave parametric oscillator (TPO) pumped by a dual-wavelength laser was proposed in this Letter. Theoretical analysis denotes that the emission of a tunable dual-color THz wave can be achieved by the simultaneous stimulated polariton scattering processes from multiple A1-symmetry phonon modes of the KTP crystal. The tunable dual-color THz wave emitted from KTP TPO was demonstrated in our experiment, where the THz frequencies simultaneously tuned from 3.15 THz to 11.63 THz and from 1.47 THz to 6.03 THz with some gaps. The maximum dual-color THz output energy of 1.31 µJ was obtained under the THz frequencies of 5.94 THz and 4.42 THz. Moreover, at a certain phase-matching angle, the THz output energies for the two frequencies were independent, which means that the dual-color THz wave emission with any energy ratio can be achieved by adjusting the pump energy ratio between a dual-wavelength laser.

Pyrazolylazophenyl Ether-Based Photoswitches: Facile Synthesis, (Near-)Quantitative Photoconversion, Long Thermal Half-Life, Easy Functionalization, and Versatile Applications in Light-Responsive Systems.

Molecular photoswitches (e.g., azobenzenes) can reversibly interconvert between their thermodynamically stable and metastable isomers upon light irradiations. However, it remains challenging to integrate both high bidirectional photoconversion and long metastable-state lifetime into a photoswitchable functionality. Here, we introduce pyrazolylazophenyl ethers (pzAzo ethers) as a class of azo photoswitches that provides quantitative (>98 %) trans-cis photoisomerization (365 nm light), near-quantitative (95-96 %) reverse isomerization (532 nm light), and a long cis-isomer half-life of three months. They can be easily synthesized in high yields and readily functionalized at one or both sides with a broad scope of substituent groups. Molecular systems incorporating pzAzo ethers can be endowed with high responsiveness, robust reversibility, and long persistent metastable states. Such superior yet pragmatic azo switches hold high promise for upgraded photoregulation in many light-responsive applications.

An Anti-Interference Scheme for UAV Data Links in Air-Ground Integrated Vehicular Networks.

As one of the main applications of the Internet of things (IoT), the vehicular ad-hoc network (VANET) is the core of the intelligent transportation system (ITS). Air-ground integrated vehicular networks (AGIVNs) assisted by unmanned aerial vehicles (UAVs) have the advantages of wide coverage and flexible configuration, which outperform the ground-based VANET in terms of communication quality. However, the complex electromagnetic interference (EMI) severely degrades the communication performance of UAV sensors. Therefore, it is meaningful and challenging to design an efficient anti-interference scheme for UAV data links in AGIVNs. In this paper, we propose an anti-interference scheme, named as Mary-MCM, for UAV data links in AGIVNs based on multi-ary (M-ary) spread spectrum and multi-carrier modulation (MCM). Specifically, the Mary-MCM disperses the interference power by expanding the signal spectrum, such that the anti-interference ability of AGIVNs is enhanced. Besides, by using MCM and multiple-input multiple-output (MIMO) technologies, the Mary-MCM improves the spectrum utilization effectively while ensuring system performance. The simulation results verify that the Mary-MCM achieves excellent anti-interference performance under different EMI combinations.

Automatic evaluation of traumatic brain injury based on terahertz imaging with machine learning.

The imaging diagnosis and prognostication of different degrees of traumatic brain injury (TBI) is very important for early care and clinical treatment. Especially, the exact recognition of mild TBI is the bottleneck for current label-free imaging technologies in neurosurgery. Here, we report an automatic evaluation method for TBI recognition with terahertz (THz) continuous-wave (CW) transmission imaging based on machine learning (ML). We propose a new feature extraction method for biological THz images combined with the transmittance distribution features in spatial domain and statistical distribution features in normalized gray histogram. Based on the extracted feature database, ML algorithms are performed for the classification of different degrees of TBI by feature selection and parameter optimization. The highest classification accuracy is up to 87.5%. The area under the curve (AUC) scores of the receiver operating characteristics (ROC) curve are all higher than 0.9, which shows this evaluation method has a good generalization ability. Furthermore, the excellent performance of the proposed system in the recognition of mild TBI is analyzed by different methodological parameters and diagnostic criteria. The system can be extensible to various diseases and will be a powerful tool in automatic biomedical diagnostics.