Mitochondria-Targetable Near-Infrared Fluorescent Probe for Visualization of Hydrogen Peroxide in Lung Injury, Liver Injury, and Tumor Models.

Hydrogen peroxide (H2O2) overexpressed in mitochondria has been regarded as a key biomarker in the pathological processes of various diseases. However, there is currently a lack of suitable mitochondria-targetable near-infrared (NIR) probes for the visualization of H2O2 in multiple diseases, such as PM2.5 exposure-induced lung injury, hepatic ischemia-reperfusion injury (HIRI), nonalcoholic fatty liver (NAFL), hepatic fibrosis (HF), and malignant tumor tissues containing clinical cancer patient samples. Herein, we conceived a novel NIR fluorescent probe (HCy-H2O2) by introducing pentafluorobenzenesulfonyl as a H2O2 sensing unit into the NIR hemicyanine platform. HCy-H2O2 exhibits good sensitivity and selectivity toward H2O2, accompanied by a remarkable "turn-on" fluorescence signal at 720 nm. Meanwhile, HCy-H2O2 has stable mitochondria-targetable ability and permits monitoring of the up-generated H2O2 level during mitophagy. Furthermore, using HCy-H2O2, we have successfully observed an overproduced mitochondrial H2O2 in ambient PM2.5 exposure-induced lung injury, HIRI, NAFL, and HF models through NIR fluorescence imaging. Significantly, the visualization of H2O2 has been achieved in both tumor-bear mice as well as surgical specimens of cancer patients, making HCy-H2O2 a promising tool for cancer diagnosis and imaging-guided surgery.

Proapoptotic effect of nonthermal pulsed ultrasound on prostate cancer cells in a nude mouse model.

BACKGROUND: Ultrasound (US) can induce cell injury, and we have previously reported that adjusting the pulse repetition frequency (PRF) of ultrasound output can induce prostate cancer cell destruction without causing a rise in the temperature of the irradiated area. In this study, we examined the mechanism of nonthermal ultrasound cell destruction, which was not fully clarified in our previous reports. METHODS: In vitro, we evaluated postirradiation cells immediately after treatment and examined membrane disruption by proliferation assay, LDH assay, and apoptosis assay. In vivo, we injected mice with human LNCaP and PC-3 prostate cancer cells and evaluated the therapeutic effects of US irradiation by H-E staining and immunostaining. RESULTS: Proliferation assays showed inhibition at 3 h postirradiation independently of PRF and cell line (p < 0.05). Quantitative assessment of apoptosis/necrosis by flow cytometry showed widely varying results depending on cell type. LNCaP showed an increase in late apoptosis at 0 h independent of PRF (p < 0.05), while PC-3 showed no significant difference at 0 h. The LDH assay showed an increase in LDH independent of PRF in LNCaP (p < 0.05 respectively), but no significant difference in PC-3. In vivo, tumor volume was compared and a significant reduction was observed at 10 Hz for LNCaP (p < 0.05) and 100 Hz for PC-3 (p < 0.001) at 3 weeks after the start of irradiation. The excised tumors were evaluated with Ki-67, Caspase-3, and CD-31 and showed a significant treatment effect independent of cell type and PRF (p < 0.001 respectively). CONCLUSION: Examining the mechanism behind the therapeutic effect of US irradiation revealed that the main effect was achieved by apoptosis induction rather than necrosis.

Rational Design of Orange-Red Emissive Carbon Dots for Tracing Lysosomal Viscosity Dynamics in Living Cells and Zebrafish.

Lysosomal viscosity is an essential microenvironment parameter in lysosomes, which is closely associated to the occurrence and development of various diseases, including cancer. Thus, accurately quantifying lysosomal viscosity changes is highly desirable for a better understanding of the dynamics and biological functions of lysosomes. In this study, lysosome self-targetable orange-red emissive carbon dots (OR-CDs) were rationally designed and developed for monitoring lysosomal viscosity fluctuations. The enhanced fluorescence of OR-CDs could be obviously observed as the viscosity increased from 1.07 to 950 cP. Moreover, the as-prepared OR-CDs could quickly enter cells for lysosome-targeting imaging and visualize viscosity variations in living cells and zebrafish. More importantly, by utilizing OR-CDs, we successfully achieved tracing the variations in lysosomal viscosity during the autophagy process. Additionally, as cancer cells possess high viscosity than normal cells, the OR-CDs have been effectively utilized for cancer imaging from cell, tissue, and organ to in vivo levels. It is expected that the developed OR-CDs not only provide a meaningful tool for visualizing investigations of lysosome viscosity-related diseases but also shed light on the development based on the nanomaterial for the clinical diagnosis of cancer.

Multi-pulse dynamic patterns in a mode-locked erbium-doped fiber laser based on an Sb2S3-PVA saturable absorber.

Multi-pulse dynamic patterns have been experimentally documented in a passively mode-locked (PML) erbium-doped fiber (EDF) laser using an Sb2S3-PVA saturable absorber (SA). The fundamental mode-locking operation, with a repetition rate of ∼3.22 MHz, a pulse width of ∼2.5 ps, a signal-to-noise ratio (SNR) of ∼50 dB and a peak power over 200 W, was achieved under a pump power from 280 to 360 mW with appropriate polarization states introduced by the polarization controllers (PCs). By rotating the orientation of the intra-cavity PCs carefully and slowly at a pump power of 350 mW, it was found that a multi-pulse bunch was transformed gradually from a single-pulse to a twelve-pulse bunch, with several intermediate transition states of multi-pulse bunches being observed. In addition, other characteristic modes including disordered multi-pulses and soliton rains have been experimentally observed by meticulously adjusting the polarization states of PCs at a pump power of 350 mW. Our systematic study clearly demonstrates that Sb2S3has potential as an effective SA for generating different operation states of multi-pulses in PML anomalous-dispersion EDF lasers.

Brazilin Inhibits the Invasion and Metastasis of Breast Cancer.

This study aimed to determine the effect of brazilin on the invasion and metastasis of breast cancer. The breast cancer MDA-MB-231 and 4T1 cells were treated with brazilin to investigate proliferation and invasion using cell proliferation assay, wound healing assay, transwell assay. BALB/C mice were randomized into normal, model, positive control, and Sappan L. extract groups (n = 6/group). The mice were injected with 4T1 cells via caudal veins to establish a lung metastasis model and via subcutaneous injection to establish a xenograft model. Metastatic nodules on the lung surface, survival rates and visceral indices were evaluated. Subcutaneous tumor volumes and weights were measured. Brazilin inhibited the proliferation of breast cancer cells and significantly inhibited the wound healing, migration, and invasion of MDA-MB-231 and 4T1 cells. Compared with the normal group, the average survival days and spleen index in the model group were significantly decreased, but the lung index and number of pulmonary metastatic nodules were significantly increased. Compared with the model group, the average survival and spleen index of dose groups were significantly increased, and the lung index, the number of pulmonary metastatic nodules, and tumor volume and weight were significantly decreased. Brazilin significantly inhibits the proliferation and metastasis of breast cancer. This study might suggest a new therapeutic agent for breast cancer.

Brazilin inhibits bladder cancer by promoting cell necroptosis.

Brazilin possesses anticancer effects, but the mechanisms are poorly understood. This study investigated the mechanisms of brazilin-induced cell death in the T24 human bladder cancer cell line. Low serum cell culture and the lactate dehydrogenase assay were used to confirm the antitumor effect of brazilin. Annexin V and propidium iodide double staining, transmission electron microscopy, fluo-3-AM assay for Ca2+ mobilization and caspase activity assay were performed to identify the type of cell death after brazilin treatment. Mitochondria membrane potentials were measured using JC-1. Quantitative real-time polymerase chain reaction and western blot analyses were performed to verify the expression of the necroptosis-related genes and proteins receptor interacting protein 1 (RIP1), RIP3 and mixed lineage kinase domain-like (MLKL). The results showed that brazilin induced necrosis in T24 cells and upregulated the mRNA and protein levels of RIP1, RIP3 and MLKL and Ca2+ influx. The necroptosis-mediated cell death was rescued by the necroptosis inhibitor necrostatin-1 (Nec-1), but not by the apoptosis inhibitor z-VAD-fmk. Brazilin repressed caspase 8 expression and decreased the mitochondrial membrane potentials; both effects were partially reversed by Nec-1. Brazilin induced physiological and morphological changes in T24 cells and RIP1/RIP3/MLKL-mediated necroptosis might be involved. In conclusion, the results confirm the involvement of necroptosis in brazilin-induced cell death and suggest that brazilin could be explored as an anticancer agent against bladder cancer.

Sub-5 nm Gate-Length Monolayer Selenene Transistors.

Two-dimensional (2D) semiconductors are being considered as alternative channel materials as silicon-based field-effect transistors (FETs) have reached their scaling limits. Recently, air-stable 2D selenium nanosheet FETs with a gate length of 5 µm were experimentally produced. In this study, we used an ab initio quantum transport approach to simulate sub-5 nm gate-length double-gate monolayer (ML) selenene FETs. When considering negative-capacitance technology and underlap, we found that 3 nm gate-length p-type ML selenene FETs can meet the 2013 ITRS standards for high-performance applications along the armchair and zigzag directions in the 2028 horizon. Therefore, ML selenene has the potential to be a channel material that can scale Moore's law down to a gate length of 3 nm.

Lipid Droplet-Specific Fluorescent Probe for In Vivo Visualization of Polarity in Fatty Liver, Inflammation, and Cancer Models.

Elucidating the intrinsic relationship between diseases and lipid droplet (LD) polarity remains a great challenge owing to the lack of the research on multiple disease models. Until now, the visualization of abnormal LD polarity in models of inflammation and clinical cancer patient samples has not been achieved. To meet the urgent challenge, we facilely synthesized a robust LD-specific and polarity-sensitive fluorescent probe (LD-TTP), which consists of a triphenylamine segment as an electron-donor group (D) and a pyridinium as an electron-acceptor moiety (A), forming a typical D-π-A molecular configuration. Owing to the unique intramolecular charge transfer effect, LD-TTP exhibits high sensitivity to polarity change in the linear range from Δf = 0.258 to 0.312, with over 278-fold fluorescence enhancement. Moreover, we revealed that LD-TTP possessed satisfactory ability for sensitively monitoring LD-polarity changes in living cells. Using LD-TTP, we first demonstrated the detection of LD-polarity changes in fatty liver tissues and inflammatory living mice via confocal laser scanning fluorescence imaging. Surprisingly, the visualization of LD polarity has been achieved not only at the cellular levels and living organs but also in surgical specimens from cancer patients, thus holding great potential in the clinical diagnosis of human cancer. All these features render LD-TTP an effective tool for medical diagnosis of LD polarity-related diseases.

Can ultrasound irradiation be a therapeutic option for prostate cancer?

BACKGROUND: Focal therapies for prostate cancer (PC) can reduce adverse events and do not lead to androgen-independent progression. Ultrasound could be used for cancer treatments if the repetition frequency is fitted to the purpose. We investigated the possible therapeutic effect of ultrasound irradiation on PC cells. MATERIALS AND METHODS: We irradiated two PC cell lines, androgen-dependent LNCaP and -independent PC-3 with ultrasound (3.0 W/cm2 , 3 MHz, irradiation time rate: 20%) for 2 minutes for 1 day or 3 consecutive days at a repetition frequency of 1, 10, or 100 Hz in vitro. Cell proliferation and apoptosis were determined after irradiation. RESULTS: Cell proliferation of PC-3 was significantly inhibited after 1 day (P < .0001) and 3 days (P < .0001) of 10 Hz ultrasound irradiation, and that of LNCaP after 1 day (P < .0001) and 3 days (P < .0001) of irradiation. LNCaP was more sensitive to ultrasound at both lower and higher cell density but PC-3 was only sensitive at a lower cell density (P < .01). Irradiation with 10 Hz ultrasound-induced significantly more PC-3 apoptotic cells than control (1 day, P = .0137; 3 days, P = .0386) rather than irradiation with 1 Hz. Apoptosis via caspase-3 was induced at 10 Hz in 1-day (P < .05) irradiation in both cell lines. CONCLUSIONS: Ultrasound irradiation with even 1 day of 10 Hz significantly inhibited cell proliferation in both LNCaP and PC-3, especially by the remarkable induction of apoptosis in vitro. Our study indicated that ultrasound irradiation can be a therapeutic option for PC and further studies in vivo will be undertaken.

High Performance Both in Low-Speed Tracking and Large-Angle Swing Scanning Based on Adaptive Nonsingular Fast Terminal Sliding Mode Control for a Three-Axis Universal Inertially Stabilized Platform.

In order to improve the performance in the practical engineering applications including so called low-speed video tracking and large-angle swing scanning imaging at the same time for a three-axis universal inertially stabilized platform (UISP), we propose an adaptive nonsingular fast terminal sliding mode control (ANFTSMC) strategy subjected to the uncertain disturbances and input saturation constraints. First of all, a second-order dynamic model is established with uncertain disturbances and input saturation constraints. Secondly, a nonsingular fast terminal sliding mode controller (NTSMC) is constructed to ensure the system error converges to zero fast in a finite time; meanwhile, a novel reaching law based on a modified normal distribution function is designed to adjust the control gain. Thirdly, an adaptive control law is designed to online estimate the parameters of the lumped uncertain disturbances. Additionally, the stability of the control system is proved by Lyapunov theory. Finally, extensive comparative simulations and experiments are carried out, the results comprehensively show the effectiveness and superiority of the proposed control method, which can accelerate convergence, weaken the chattering, and has the better control accuracy and robust performance both in the low-speed tracking and large-angle swing scanning applications. Moreover, the exact dynamic model and the prior knowledge of the upper bounds of the disturbances are not required during the procedure of the controller design, which make it have more extensive application value in practical engineering.

Design and Simulation Test of an Open D-Dot Voltage Sensor.

Nowadays, sensor development focuses on miniaturization and non-contact measurement. According to the D-dot principle, a D-dot voltage sensor with a new structure was designed based on the differential D-dot sensor with a symmetrical structure, called an asymmetric open D-dot voltage sensor. It is easier to install. The electric field distribution of the sensor was analyzed through Ansoft Maxwell and an open D-dot voltage sensor was designed. This open D-voltage sensor is characteristic of accessible insulating strength and small electric field distortion. The steady and transient performance test under 10 kV-voltage reported satisfying performances of the designed open D-dot voltage sensor. It conforms to requirements for a smart grid measuring sensor in intelligence, miniaturization and facilitation.

Silencing p75NTR regulates osteogenic differentiation and angiogenesis of BMSCs to enhance bone healing in fractured rats.

BACKGROUND: Fractures heal through a process that involves angiogenesis and osteogenesis but may also lead to non-union or delayed healing. Bone marrow mesenchymal stem cells (BMSCs) have been reported to play a pivotal role in bone formation and vascular regeneration and the p75 neurotrophin receptor (p75NTR) as being an important regulator of osteogenesis. Herein, we aim to determine the potential mediation of BMSCs by p75NTR in bone healing. METHODS: Rat BMSCs were identified by flow cytometry (FCM) to detect cell cycle and surface markers. Then transfection of si/oe-p75NTR was performed in BMSCs, followed by Alizarin red staining to detect osteogenic differentiation of cells, immunofluorescence double staining was performed to detect the expression of p75NTR and sortilin, co-immunoprecipitation (CO-IP) was conducted to analyze the interaction between p75NTR and sortilin, and EdU staining and cell scratch assay to assess the proliferation and migration of human umbilical vein endothelial cells (HUVECs). The expression of HIF-1α, VEGF, and apoptosis-related proteins were also detected. In addition, a rat fracture healing model was constructed, and BMSCs-si-p75NTR were injected, following which the fracture condition was observed using micro-CT imaging, and the expression of platelet/endothelial cell adhesion molecule-1 (CD31) was assessed. RESULTS: The results showed that BMSCs were successfully isolated, p75NTR inhibited apoptosis and the osteogenic differentiation of BMSCs, while si-p75NTR led to a decrease in sortilin expression in BMSCs, increased proliferation and migration in HUVECs, and upregulation of HIF-1α and VEGF expression. In addition, an interaction was observed between p75NTR and sortilin. The knockdown of p75NTR was found to reduce the severity of fracture in rats and increase the expression of CD31 and osteogenesis-related proteins. CONCLUSION: Silencing p75NTR effectively modulates BMSCs to promote osteogenic differentiation and angiogenesis, offering a novel perspective for improving fracture healing.

Low-Dose CT Image Super-resolution Network with Noise Inhibition Based on Feedback Feature Distillation Mechanism.

Low-dose computed tomography (LDCT) has been widely used in medical diagnosis. In practice, doctors often zoom in on LDCT slices for clearer lesions and issues, while, a simple zooming operation fails to suppress low-dose artifacts, leading to distorted details. Therefore, numerous LDCT super-resolution (SR) methods have been proposed to promote the quality of zooming without the increase of the dose in CT scanning. However, there are still some drawbacks that need to be addressed in existing methods. First, the region of interest (ROI) is not emphasized due to the lack of guidance in the reconstruction process. Second, the convolutional blocks extracting fix-resolution features fail to concentrate on the essential multi-scale features. Third, a single SR head cannot suppress the residual artifacts. To address these issues, we propose an LDCT CT joint SR and denoising reconstruction network. Our proposed network consists of global dual-guidance attention fusion modules (GDAFMs) and multi-scale anastomosis blocks (MABs). The GDAFM directs the network to focus on ROI by fusing the extra mask guidance and average CT image guidance, while the MAB introduces hierarchical features through anastomosis connections to leverage multi-scale features and promote the feature representation ability. To suppress radial residual artifacts, we optimize our network using the feedback feature distillation mechanism (FFDM) which shares the backbone to learn features corresponding to the denoising task. We apply the proposed method to the 3D-IRCADB and PANCREAS datasets to evaluate its ability on LDCT image SR reconstruction. The experimental results compared with state-of-the-art methods illustrate the superiority of our approach with respect to peak signal-to-noise (PSNR), structural similarity (SSIM), and qualitative observations. Our proposed LDCT joint SR and denoising reconstruction network has been extensively evaluated through ablation, quantitative, and qualitative experiments. The results demonstrate that our method can recover noise-free and detail-sharp images, resulting in better reconstruction results. Code is available at https://github.com/neu-szy/ldct_sr_dn_w_ffdm .

Augmented-reality-based surgical navigation for endoscope retrograde cholangiopancreatography: A phantom study.

BACKGROUND: Endoscope retrograde cholangiopancreatography is a standard surgical treatment for gallbladder and pancreatic diseases. However, surgeons is at high risk and require sufficient surgical experience and skills. METHODS: (1) The simultaneous localisation and mapping technique to reconstruct the surgical environment. (2) The preoperative 3D model is transformed into the intraoperative video environment to implement the multi-modal fusion. (3) A framework for virtual-to-real projection based on hand-eye alignment. For the purpose of projecting the 3D model onto the imaging plane of the camera, it uses position data from electromagnetic sensors. RESULTS: Our AR-assisted navigation system can accurately guide physicians, which means a distance of registration error to be restricted to under 5 mm and a projection error of 5.76 ± 2.13, and the intubation procedure is done at 30 frames per second. CONCLUSIONS: Coupled with clinical validation and user studies, both the quantitative and qualitative results indicate that our navigation system has the potential to be highly useful in clinical practice.

Effects of porous structure on the deformation failure mechanism of cement sheaths for wellbores.

The influence and mechanism of porous structure on the deformation failure of cement sheaths under hydraulic pressure is still unclear. To solve this problem, a net slurry cement sheath and a liquid silicon cement sheath were prepared by using a cement material and a liquid silicon suspension. The distributions of the pore radius and spatial location were analyzed using computed tomography scanning and statistics to obtain their probability density distribution functions. Based on the distribution functions, the single-layer and double-layer porous reconstruction models of the net slurry cement sheath and liquid silicon cement sheath were constructed using a FLAC 3D program. A series of numerical simulations were conducted to study the deformation failure of the cement sheaths under in situ stress and hydraulic pressure. The effects of the porous and double-layer structures on the breakdown pressure, plastic failure zone, radial deformation, and stress distribution of the cement sheaths were analyzed. As a result, the mechanisms for the influence of the porous and double-layer structures on the failure mode, failure path, and interaction between the cement sheath and metal casing were revealed. The results of this research provide a theoretical basis for an in-depth understanding of the failure mechanisms of porous cement sheaths.

Enrichment of Isaria felina Culture with Selenium Enhances its in vivo Antitumor Effects on H22 Hepatoma via Decreasing the Expression of VEGF.

BACKGROUND: The polysaccharide extract of C. sinensis, Isaria felina (IF), has antitumor effects. Selenium (Se) can improve disease prevention and reduce the toxicity of toxic elements, but the effect of Se-enriched IF on hepatoma remains unknown. OBJECTIVE: To determine the organic transformation of Se and compare the antitumor effects between Se-enriched IF (IF-Se) and IF on xenograft H22 hepatoma-bearing mice. METHODS: Se was added to the solid-state culture medium, and the organic Se content was detected by HPLC-ICP-MS. Forty-two Kunming mice were randomly divided into seven groups to test the antitumor effects of low- (300 mg/kg) and high- (600 mg/kg) doses of IF-Se and IF through xenograft. Huai'er granules were administered as the positive control. In addition, interleukin (IL)-2 and vascular endothelial growth factor (VEGF) expressions were measured by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry method. RESULTS: The conversion rate in the IF-Se70, IF-Se140, and IF-Se280 groups were 91.5%, 93.4%, and 89.3%, respectively. Therefore, IF-Se140 was used to carry out the subsequent experiments. The tumor inhibition rates of IF-Se were significantly higher compared with IF (P < 0.05). Moreover, the spleen coefficient, IL-2, and VEGF expression levels significantly decreased (all Ps < 0.05), and the thymus coefficient significantly increased (P < 0.05) in the high-dose IF-Se group compared with the model control group. CONCLUSION: The inhibitory effects of IF on H22 hepatoma-bearing mice were enhanced after Se enrichment. Therefore, Se-enriched IF might be a new strategy for treating hepatoma.

Preparation and application of patient-derived xenograft mice model of colorectal cancer.

Objectives: Patient-derived xenograft (PDX) model becomes a more and more important tool for tumor research. This study aimed to establish a colorectal cancer PDX model and verify its applicability. Materials and Methods: Fresh human colorectal cancer tissue was surgically removed and subcutaneously inoculated into immunodeficient mice to establish the PDX model. Hematoxylin and eosin (HE) staining and immunohistochemical staining were used to evaluate the model. The successful PDX model was selected to study the efficacy of capecitabine in treating colorectal cancer. Results: HE staining showed that the PDX mice model of colorectal cancer could preserve the histological characteristics of the primary tumor. Immunohistochemistry staining showed α-fetoprotein (AFP), carcinoembryonic antigen (CEA), and E-cadherin were strongly positively expressed in primary human and PDX tumor tissues, with a high degree of similarity. Capecitabine significantly inhibited PDX tumor growth and reduced the expression of AFP and CEA proteins in the tumor tissues (all P s<0.05). Conclusion: We successfully established a colorectal cancer PDX model, and the PDX model could retain the histological and biological characteristics of the primary tumor. Using this PDX model, we revealed that capecitabine at a dose of 300-400 mg/kg can effectively treat colorectal cancer, and no significant difference in toxicity was found among different dose groups. The current work provides a feasible framework for establishing and validating the PDX tumor model to better facilitate the evaluation of drug efficacy and safety.

Ultrasound examination for the diagnosis of chronic anterior talofibular ligament injury.

BACKGROUND: Anterior talofibular ligament (ATFL) injury is a commonly seen sports-related injury and a major underlying pathology of chronic ankle instability. However, it is difficult to accurately identify chronic injury of the ATFL. PURPOSE: To investigate the value of ultrasound (US) examination in identifying chronic ATFL injury. MATERIAL AND METHODS: We evaluated 83 consecutive patients who underwent US examination for diagnosis of the ATFL injury and subsequent ankle arthroscopy. The arthroscopic findings were used as the reference standard. RESULTS: Forty-four patients were found to have ATFL injury on arthroscopy. The accuracy of US examination for the detection of ATFL injury was 95.2%, with sensitivity of 97.7%, specificity of 92.3%, positive predictive value of 93.5%, negative predictive value of 97.3%, positive likelihood ratio of 12.7, and negative likelihood ratio of 0.025. CONCLUSION: US examination is a reliable and accurate method to evaluate chronic ATFL injury.

[Diagnostic efficacy of an ultrasound quantitative method in a rat model of experimental liver fibrosis].

To evaluate the efficacy of an ultrasound-based quantitative method to diagnose liver fibrosis using a rat model. Ultrasonography was performed on the livers of 90 Sprague-Dawley rats with or without thioacetamide-induced fibrosis. The liver capsule thickness and 13 texture parameters of gray level co-occurrence matrix were extracted from the standard sonograms. After sacrifice, severity of liver fibrosis (S0-S4 classification) was diagnosed by histopathology. Analysis of variance and correlation statistical tests were used to analyze the differences between groups and determine the relationships between each of the 14 quantitative ultrasound index points and the histological results, respectively. Discriminant analysis models were developed for quantitative diagnosis of liver fibrosis, and the leave-one-case-out method was used to verify the efficiency of models. All 14 indices were significantly correlated with the histological stages of fibrosis (P less than 0.05). The accuracy of the discriminant model for S0, S1, S2, S3 and S4 was 83.3%, 84.2%, 70.0%, 50.0% and 88.2%, respectively. In addition, 73.3% of cross-validated rats were accurately classified. Grouping S0 as no fibrosis, S1 as mild fibrosis, S2 with S3 as moderate to severe fibrosis and S4 as early cirrhosis increased the accuracy of the discriminant model for these four groups (respectively, 91.7%, 84.2%, 69.0% and 88.2%) and allowed for 78.9% of cross-validated rats to be correctly identified. Ultrasonography combined with texture analysis was a novel and accurate method to diagnose liver fibrosis in a rat model; further studies may provide insights into its applicability for quantitating liver fibrosis in other animal models or in clinic.