Objective : To investigate the effect of solasonine regulation of the STAT3 signaling pathway on the bio- logical behavior of lung adenocarcinoma cells． Methods : H1299 cells were treated with 0. 125，0. 25，0. 5 and 0. 75 mmol /L solasonine，respectively．The proliferative activity of H1299 cells was detected by CCK-8．The mi- gration and invasion ability of H1299 cells were detected by scratch，Transwell migration and invasion assay．The apoptosis level of H1299 cells was detected by flow cytometry and Hoechest 33258 /PI double staining．The protein expression levels of STAT3，p-STAT3 ，Bcl-2 ，Bax ，Caspase-3 ，Cl-Caspase-3 ，Snail ，Slug ，N-cadherin and E- cadherin in H1299 cells were detected by Western blot assay． Results: Solasonine at different concentrations sig- nificantly reduced the proliferation of H1299 cells (P＜0. 05) ．0. 125 and 0. 25 mmol /L solasonine promoted the apoptosis of H1299 cells (P＜0. 05) and inhibited the migration and invasion of H1299 cells (P＜0. 05) ．Solaso- nine inhibited the expression of STAT3，p-STAT3 and Bcl-2 proteins，enhanced the expression of Bax，Caspase-3 and Cl-Caspase-3 proteins．Solasonine inhibited the activation of STAT3 in cells，reduced Snail and Slug protein expression levels，enhanced E-cadherin，reduced N-cadherin(P＜0. 05) ． Conclusion Solasonine can inhibit the activation of STAT3 ，activate the Bcl-2 /Bax / Caspase3 apoptosis pathway ，inhibit the continuous proliferation of lung adenocarcinoma H1299 cells，and promote the apoptosis of lung adenocarcinoma H1299 cells．Meanwhile，it can inhibit the activation of STAT3，reduce the expression of Snail / Slug protein，affect the EMT transformation of lung adenocarcinoma H1299 cells，and inhibit the migration and invasion of lung adenocarcinoma H1299 cells．

Objective:To develop an artificial intelligence (AI)-based automatic scoring model for magnetic resonance imaging-detected extramural vascular invasion (AI-mrEMVI) and evaluate its performance and prognostic value in patients with rectal cancer.Methods:In this multicenter retrospective cohort study, a total of 2 501 rectal cancer patients from seven centers between November 2012 and December 2020 were included and divided into completely independent training ( n=1 830) and validation ( n=671) cohorts. A nnUNet-based AI-mrEMVI scoring model was constructed. Manual mrEMVI scores assigned by two radiologists served as the reference standard for accessing the accuracy of the AI-mrEMVI scoring. Kaplan-Meier survival analysis and Cox regression were used to evaluate the prognostic stratification ability of the AI-mrEMVI scores. The concordance index (C-index) was calculated to evaluate prognostic performance. Results:In the validation cohort, the manual mrEMVI scores were 0-2 in 425 patients (63.3%), 3 in 89 (13.4%), and 4 in 157 (23.4%). The AI-mrEMVI model identified 0-2 in 375 patients (55.9%), 3 in 95 (14.2%), and 4 in 201 (30.0%), with an overall accuracy of 81.1% (544/671, 95% CI 77.9%-84.0%). The 3-year disease-free survival (DFS) rates for patients with AI-mrEMVI scores of 0-2, 3, and 4 were 85.2%, 70.0%, and 58.2%, respectively, and the 5-year overall survival (OS) rates were 87.2%, 81.6%, and 62.6%, respectively (DFS: χ2=48.74, P<0.001; OS: χ2=30.04, P<0.001). Multivariable Cox regression showed that for DFS, AI-mrEMVI scores of 3 and 4 were associated with hazard ratios ( HR) of 1.75 (95% CI 1.11-2.77, P=0.016) and 2.65 (95% CI 1.86-3.78, P<0.001), respectively. For OS, an AI-mrEMVI score of 4 was associated with an HR of 2.56 (95% CI 1.62-4.03, P<0.001). The C-index values of the AI-mrEMVI scoring model for predicting DFS and OS were 0.647 (95% CI 0.608-0.686) and 0.650 (95% CI 0.598-0.702), respectively. Conclusion:The proposed AI-mrEMVI automatic scoring model demonstrated high diagnostic accuracy and performed favorably in predicting DFS and OS prognostic risk in patients with rectal cancer.

Objective:To develop an artificial intelligence (AI)-based automatic scoring model for magnetic resonance imaging-detected extramural vascular invasion (AI-mrEMVI) and evaluate its performance and prognostic value in patients with rectal cancer.Methods:In this multicenter retrospective cohort study, a total of 2 501 rectal cancer patients from seven centers between November 2012 and December 2020 were included and divided into completely independent training ( n=1 830) and validation ( n=671) cohorts. A nnUNet-based AI-mrEMVI scoring model was constructed. Manual mrEMVI scores assigned by two radiologists served as the reference standard for accessing the accuracy of the AI-mrEMVI scoring. Kaplan-Meier survival analysis and Cox regression were used to evaluate the prognostic stratification ability of the AI-mrEMVI scores. The concordance index (C-index) was calculated to evaluate prognostic performance. Results:In the validation cohort, the manual mrEMVI scores were 0-2 in 425 patients (63.3%), 3 in 89 (13.4%), and 4 in 157 (23.4%). The AI-mrEMVI model identified 0-2 in 375 patients (55.9%), 3 in 95 (14.2%), and 4 in 201 (30.0%), with an overall accuracy of 81.1% (544/671, 95% CI 77.9%-84.0%). The 3-year disease-free survival (DFS) rates for patients with AI-mrEMVI scores of 0-2, 3, and 4 were 85.2%, 70.0%, and 58.2%, respectively, and the 5-year overall survival (OS) rates were 87.2%, 81.6%, and 62.6%, respectively (DFS: χ2=48.74, P<0.001; OS: χ2=30.04, P<0.001). Multivariable Cox regression showed that for DFS, AI-mrEMVI scores of 3 and 4 were associated with hazard ratios ( HR) of 1.75 (95% CI 1.11-2.77, P=0.016) and 2.65 (95% CI 1.86-3.78, P<0.001), respectively. For OS, an AI-mrEMVI score of 4 was associated with an HR of 2.56 (95% CI 1.62-4.03, P<0.001). The C-index values of the AI-mrEMVI scoring model for predicting DFS and OS were 0.647 (95% CI 0.608-0.686) and 0.650 (95% CI 0.598-0.702), respectively. Conclusion:The proposed AI-mrEMVI automatic scoring model demonstrated high diagnostic accuracy and performed favorably in predicting DFS and OS prognostic risk in patients with rectal cancer.

Objective : To investigate the effects of immunoglobulin gene superfamily 10 (IGSF10) on prolifera- tion，migration and invasion of lung adenocarcinoma cells． Methods : ioinformatics was applied to study the ex- pression levels of IGSF10 in tumor tissues and normal tissues． Western blot and quantitative real-time PCR ( qPCR) were used to detect the expression level of IGSF10 in lung adenocarcinoma cell lines and normal lung epi- thelial cells．Knockdown of IGSF10，the effect of knockdown of IGSF10 on proliferation，migration and invasion of lung adenocarcinoma A549 cells was examined using cell counting kit-8 ( CCK-8) ，Transwell migration and inva- sion assay，scratch assay and plate cloning assay．The effects of knockdown of IGSF10 on the expression of invasion and migration-related genes in A549 cells were examined by Western blot and qPCR assays. Results : IGSF10 ex- pression in lung adenocarcinoma tissues was lower than that in normal tissues (P ＜0. 05) ．IGSF10 expression in lung adenocarcinoma cell lines was lower than that in lung epithelial cells (P＜0. 05) ．Knockdown of IGSF10 pro- moted the ability of lung adenocarcinoma A549 cells to proliferate ，proliferation ，migration and invasion ( P < 0. 05) ．Knockdown of IGSF10 promoted the expression of regulatory epithelial-mesenchymal transition marker Neu- ral-cadherin (N-cadherin) and key transcription factors Snail family transcriptional repressor 1 (Snail) and Snail family transcriptional repressor 2 (Slug) (P＜0. 05) and inhibited the expression of Epithelial-cadherin (E-cad- herin) (P＜0. 05) ． Conclusion Knockdown of IGSF10 may promote proliferation，migration and invasion of lung adenocarcinoma cells through activation of Snail，Slug / E-cadherin signaling axis，and this result may provide a po- tential new target for clinical diagnosis and treatment of lung adenocarcinoma.

Objective:To explore the risk factors associated with the clinical progression of COVID-19 infection in kidney transplant(KT)recipients during the spread of Omicron variant and evaluate the effectiveness of anti-RNA virus agents in blocking the clinical progression of COVID-19 in these recipients.Methods:Retrospective analysis was conducted for the clinical data on COVID-19 infection in 232 KT recipients followed up from December 4, 2022 to January 31, 2023 at Department of Renal Transplantation, Organ Transplantation Center, Beijing Tsinghua Changgung Hospital.Inclusion criteria were age ≥18 years and stable kidney function without renal replacement therapy.The follow-up time was 30 days after COVID-19 infection.Based upon whether or not there was an infection of COVID-19, KT recipients were divided into two groups of infection(181 cases)and non-infection(51 cases). In infection group, recipients were further assigned into two sub-groups of disease progression(n=23)and stable(158 cases)according to whether or not there was a progression to severe disease.Various factors such as gender, age, body mass index(BMI), time after transplantation, underlying diseases(history of hypertension, diabetes mellitus, coronary heart disease & chronic lung disease), smoking history and dosing of anti-RNA virus agents were collected.Pearson χ2 test or Fisher's exact probability method was utilized for examining enumeration data while Mann-Whitney U test for measurement data.Univariate Logistic regression analysis was conducted and variables with P<0.05 were included into multifactorial Logistic regression analysis to identify independent risk factors for clinical progression of COVID-19 infection in KT recipients. Results:Among 232 KT recipients, infection rate of COVID-19 was 78.0%(181/232). The clinical classification was mild(112 cases), moderate(46 cases), severe(21 cases)and critical(n=2 cases). The severe rate was 12.7%(23/181). After infection with COVID-19, the proportion of KT recipients aged ≥65 years progressing from mild/moderate to severe was higher than those aged<65 years[38.5%(5/13)vs 10.7%(18/168)]. The difference was statistically significant( P=0.014); The proportion of diabetic KT recipients progressing from mild/moderate to severe was higher than those without diabetes[19.1%(13/68)vs 8.8%(10/113)]. The difference was statistically significant( P=0.045). Univariate Logistic analysis showed similar results.Age≥65 years( OR=5.21, 95% CI: 1.54-17.64, P=0.008)or diabetes mellitus( OR=2.44, 95% CI: 1.003-5.911, P=0.049)were the risk factors for COVID-19 infection recipients progressing from mild/moderate to severe disease.Multivariate Logistic analysis revealed that age ≥65 years( OR=4.03, 95% CI: 1.14-14.34, P=0.031)was an independent risk factor for COVID-19 infection recipients progressing from mild/moderate to severe.Among 181 cases of COVID-19 mild/medium infected patients, 18 cases received nimativir/ritonavir and 10 cases had azvudine for anti-RNA virus treatment.However, none of them progressed to severe; 153 cases did not use anti-RNA virus drugs and 23 cases(15.0%)progressed to severe disease and the difference was statistically significant( P=0.028). Among 23 severe cases, 14 cases received nirmatrelvir/ritonavir and 2 cases had azivudine for anti-RNA virus treatment.The former did not progress to critical disease while 1 case in the latter progressed to critical illness and death; 1/7 recipients not using anti-RNA virus agents progressed to critical illness and died while another 6 cases did not progress to critical illness. Conclusions:KT recipients aged ≥65 years or diabetes mellitus have a greater risk of progression from mild/moderate to severe disease after COVID-19 infection.Among them, age ≥65 years is an independent risk factor for patients with COVID-19 infection to progress from mild/moderate to severe.Antiviral treatment with nirmatrelvir/ritonavir or azivudine in KT recipients during mild/moderate stage of COVID-19 infection can significantly reduce the rate of severe disease.Treatment with Nirmatrelvir/Ritonavir is still effective in the severe stage.

Hospitalization ; Humans ; Infant, Newborn ; Intensive Care Units, Neonatal ; Reproductive Techniques, Assisted ; Retrospective Studies

Objective: To explore the effects and mechanism of water-soluble chitosan hydrogel on infected full-thickness skin defect wounds in diabetic mice. Methods: The experimental research method was adopted. The control hydrogel composed of polyvinyl alcohol and gelatin, and the water-soluble chitosan hydrogel composed of the aforementioned two materials and water-soluble chitosan were prepared by the cyclic freeze-thaw method. The fluidity of the two dressings in test tube before and after the first freeze-thawing was generally observed, and the difference in appearance of the final state of two dressings in 12-well plates were compared. According to random number table (the same grouping method below), the cell strains of L929 and HaCaT were both divided into water-soluble chitosan hydrogel group and control hydrogel group, respectively. After adding corresponding dressings and culturing for 24 h, the cell proliferation activity was measured using cell counting kit 8. Rabbit blood erythrocyte suspensions were divided into normal saline group, polyethylene glycol octyl phenyl ether (Triton X-100) group, water-soluble chitosan hydrogel group, and control hydrogel group, which were treated accordingly and incubated for 1 hour, and then the hemolysis degree of erythrocyte was detected by a microplate reader. Twenty-four female db/db mice aged 11-14 weeks were selected, and full-thickness skin defect wounds on their backs were inflicted and inoculated with the methicillin-resistant Staphylococcus aureus (MRSA), 72 h later, the mice were divided into blank control group, sulfadiazine silver hydrogel group, control hydrogel group, and water-soluble chitosan hydrogel group, which were treated accordingly. On post injury day (PID) 0 (immediately), 7, 14, and 21, the healing of the wound was observed. On PID 14 and 21, the wound healing rate was calculated. On PID 14, MRSA concentration in wounds was determined. On PID 21, the wounds were histologically analyzed by hematoxylin and eosin staining; the expression of CD31 in the wounds was detected by immunofluorescence method, and its positive percentage was calculated. Raw264.7 cells were taken and divided into interleukin-4 (IL-4) group, blank control group, control hydrogel group, and water-soluble chitosan hydrogel group, which were treated accordingly. At 48 h of culture, the percentages of CD206 positive cells were detected by flow cytometry. The number of samples was all 3. Data were statistically analyzed with independent sample t test, one-way analysis of variance, analysis of variance for repeated measurement, least significant difference test, and Dunnett T3 test. Results: Two dressings in test tube had certain fluidity before freeze-thawing and formed semi-solid gels after freeze-thawing for once. The final forms of two dressings in 12-well plates were basically stable and translucent sheets, with little difference in transparency. At 24 h of culture, the cell proliferation activities of L929 and HaCaT in water-soluble chitosan hydrogel group were significantly higher than those in control hydrogel group (with t values of 6.37 and 7.50, respectively, P<0.01). At 1 h of incubation, the hemolysis degree of erythrocyte in water-soluble chitosan hydrogel group was significantly lower than that in Triton X-100 group (P<0.01), but similar to that in normal saline group and control hydrogel group (P>0.05). On PID 0, the traumatic conditions of mice in the 4 groups were similar. On PID 7, more yellowish exudates were observed inside the wound in blank control group and control hydrogel group, while a small amount of exudates were observed in the wound in sulfadiazine silver hydrogel group and water-soluble chitosan hydrogel group. On PID 14, the wounds in blank control group and control hydrogel group were dry and crusted without obvious epithelial coverage; in sulfadiazine silver hydrogel group, the scabs fell off and purulent exudate was visible on the wound; in water-soluble chitosan hydrogel group, the base of wound was light red and obvious epithelial coverage could be observed on the wound. On PID 14, the wound healing rate in water-soluble chitosan hydrogel group was significantly higher than that in the other 3 groups (all P<0.01). On PID 21, the wound in water-soluble chitosan hydrogel group was completely closed, while the wounds in the other 3 groups were not completely healed; the wound healing rate in water-soluble chitosan hydrogel group was significantly higher than that in the other 3 groups (all P<0.01). On PID 14, the concentration of MRSA in the wound in water-soluble chitosan hydrogel group was significantly lower than that in blank control group (P<0.01), but similar to that in control hydrogel group and sulfadiazine silver hydrogel group (P>0.05). On PID 21, the new epidermis was severely damaged in blank control group; the epidermis on the wound in control hydrogel group also had a large area of defect; complete new epidermis had not yet being formed on the wound in sulfadiazine silver hydrogel group; the wound in water-soluble chitosan hydrogel group was not only completely covered by the new epidermis, the basal cells of the new epidermis were also regularly aligned. On PID 21, the percentage of CD31 positivity in the wound in water-soluble chitosan hydrogel group was (2.19±0.35)%, which was significantly higher than (0.18±0.05)% in blank control group, (0.23±0.06)% in control hydrogel group, and (0.62±0.25)% in sulfadiazine silver hydrogel group, all P<0.01. At 48 h of culture, the percentage of CD206 positive Raw264.7 cells in water-soluble chitosan hydrogel group was lower than that in IL-4 group (P>0.01) but significantly higher than that in blank control group and control hydrogel group (P<0.05 or P<0.01). Conclusions: The water-soluble chitosan hydrogel has good biosafety and can induce higher level of macrophage M2 polarization than control hydrogel without water-soluble chitosan, so it can enhance the repair effect of MRSA-infected full-thickness skin defect wounds in diabetic mice and promote rapid wound healing.
Mice ; Female ; Animals ; Rabbits ; Interleukin-4 ; Hydrogels/pharmacology* ; Wound Healing ; Chitosan/pharmacology* ; Diabetes Mellitus, Experimental ; Water ; Methicillin-Resistant Staphylococcus aureus ; Gelatin ; Polyvinyl Alcohol ; Hemolysis ; Saline Solution ; Eosine Yellowish-(YS) ; Hematoxylin ; Octoxynol ; Silver ; Phenyl Ethers ; Sulfadiazine

Objective: To explore and clarify the correlation between short-term aggressive intrasegmental recurrence (AIR) and functional magnetic resonance imaging after radiofrequency ablation of hepatocellular carcinoma (HCC). Methods: A retrospective analysis of 1 262 patients with HCC who underwent radiofrequency ablation (RFA) in our hospital from January 2012 to June 2018, all patients were confirmed by pathology as HCC, of which 30 patients were found to have AIR during radiographic follow-up within 3 months after surgery, another 35 patients with disease progression who were controlled in a short period of time were randomly selected as the control group. All the enrolled patients underwent dynamic enhanced magnetic resonance imaging (DCE-MRI) and diffusion weighted imaging (DWI) scanning before surgery, and the differences in clinical data, lesion location, and functional magnetic resonance parameters between the two groups were compared, and their correlation with AIR after RFA was analyzed. Chi-square test, t test and Pearson test were used. Results: The lesions in the AIR group were significantly more in the Ⅰand Ⅳsegments than that in the control group (P<0.05), and there was no significant difference in other liver segments (P>0.05). There was no significant difference in the lesion morphology between the two groups (P>0.05), and there was a significant difference in the early enhancement pattern of the lesions (P<0.05), and the early arterial enhancement rate and apparent diffusion coefficient (ADC) value of the AIR group were significantly lower than the control group (P<0.05). Further correlation analysis found that early enhancement of the arterial artery, early arterial enhancement rate, ADC value and lesion location were associated with AIR and were positively correlated, r values were 0.455, 0.633, 0.518, 0.375 and 0.287 (P<0.05). Conclusion The short-term AIR and functional imaging parameters (arterial early enhancement, early arterial enhancement rate, ADC value) and the liver segment (Ⅰ and Ⅳ) were highly correlated with radiofrequency ablation.

Objective:To investigate the preliminary clinical and radiographic outcomes of percutaneous endoscopic lumbar discectomy (PELD) combined with oblique lateral interbody fusion (OLIF) for the degenerative lumbar spondylolisthesis, lumbar spine instability or lumbar spinal stenosis with ruptured disc herniation.Methods:Data of 11 patients with degenerative lumbar spondylolisthesis, lumbar spine instability or lumbar spinal stenosis with ruptured disc herniation who had undergone PELD combined with OLIF between March 2017 to July 2018 in our spine surgery center were retrospectively analyzed. There were 5 males and 6 females with an average age of 61.2±6.8 years old. All the patients were diagnosed with degenerative lumbar diseases including lumbar spondylolisthesis (7 cases), lumbar spinal stenosis (3 cases) and segmental instability (1 case). The patients were treated with PELD combined with OLIF. The visual analogue scale (VAS) scores of low back pain and lower limb pain and the Oswestry disability index (ODI) of lumbar function, spinal canal anteroposterior diameter, intervertebral disc height, vertical diameter of intervertebral foramen, segmental angle and the whole lumbar lordotic angle were collected.Results:All patients received PELD with local anesthesia before OLIF with general anesthesia. The mean operation time was 52.3±13.2 min and the mean blood loss was 10.9±4.7 ml for PELD. The mean operation time was 56.8±18.0 min and the mean blood loss was 65.5±24.6 ml for OLIF. All patients were followed up for an average of 11.2 months. At the latest follow-up, the mean VAS score for back pain was 1.3±0.8, the mean VAS score for leg pain 1.1±0.5, the mean ODI 14.6%±5.3%, thus all of those were improved significantly compared to those of pre-operation ( t=10.37, 16.49, 8.73; P< 0.05). The radiographic results showed the mean pre-operative intervertebral disc height, vertical diameter of intervertebral foramen, spinal canal anteroposterior diameter, segmental angle, and lumbar lordosis angle was 7.1±1.2 mm, 15.3±2.2 mm, 6.2±1.3 mm, 10.2°±3.5°, 16.2°±6.2°, and thus all of those were increased significantly to the latest follow-up 11.5±1.8 mm, 19.2±2.6 mm, 10.4±2.5 mm, 19.3°±7.8°, 27.4°±8.3°, respectively ( t=5.83, 4.21, 6.59, 10.32, 7.65; P< 0.05). One of the patients had weakness of flexor hip strength and one had a transient paresthesia immediately post-operation. All symptoms were relieved within 1 month. Another one case had cage subsidence and encountered serious back pain after 1 month, and alleviated after percutaneous pedicle screw fixation. Conclusion:PELD combined with OLIF can overcome the limitations of OLIF with indirect decompression effects, resulting in successful direct neural decompression without posterior decompressive procedures and providing a satisfactory outcome for the patients with degenerative lumbar diseases with ruptured disc herniation.

Objective To explore the application of double-parameter three-dimension arterial spin labeling (3D-ASL) in evaluating collateral circulation in patients with unilateral chronic middle cerebral artery (MCA) occlusion.Methods From May 2015 to November 2017,24 patients with unilateral chronic MCA occlusion were scanned in Yantaishan Hospital by conventional MRI,DWI,3D-TOF-MRA and 3D-ASL (post-labeling delays:1.5 s and 2.5 s respectively) using a 3.0 T MR scanner.The cerebral blood flow (CBF) values were measured in region of interest in the occlusive cortical area and in the contralateral normal cerebral area.The differences in CBF value measured by 3D-ASL (PLD=1.5 s and PLD=2.5 s) were analyzed by statistical methods.Results All the patients (n=24) on 3D-ASL (PLD=1.5 s) presented with apparent hypoperfusion in the MCA occlusion territory;but 3D-ASL (PLD=2.5 s) demonstrated the basically same perfusion in bilateral MCA territories,without apparent hypoperfusion in one cerebral hemisphere.The subtraction images of 3D-ASL (PLD 2.5 s-PLD 1.5 s)presented laminated high signal areas in the cortical region of MCA occlusion.There was no statistically significant difference in CBF value of the contralateral normal cerebral area between measurements by 3D-ASL (PLD=1.5 s) and by 3D-ASL (PLD=2.5 s) (6.39±5.01 mL/100 g·min versus 55.87±6.89 mL/100 g· min) (P＞0.05).The CBF value of region of interest in the occluded cortical area (23.34±4.53 mL/100 g· min) was significantly lower than that in the contralateral normal cerebral area (55.87±6.89 mL/100 g·min) by 3D-ASL (PLD=1.5 s) (P＜0.05).The CBF value of region of interest in the occluded cortical area (53.93±8.59 mL/100 g·min) by 3D-ASL (PLD=2.5 s) was significantly higher than that by 3D-ASL (PLD=1.5 s) (23.34±4.53 mL/100 g·min) (P＜0.05).There was no statistically significant difference between the CBF value of region of interest in the occluded cortical area and that in the contralateral normal cerebral area by 3D-ASL (PLD=2.5 s) (P＞0.05).Conclusions 3D-ASL (PLD=1.5 s and PLD=2.5 s) can noninvasively and intuitively demonstrate the collateral circulation compensation in patients with chronic MCA occlusion.3D-ASL (PLD=1.5 s) can reflect the first-order collateral circulation compensation while 3D-ASL (PLD=2.5 s) can reflect accurately the secondary collateral circulation compensation.