Diabetic macular edema(DME)may occur at any stage of diabetic retinopathy(DR)and represents a significant cause of visual impairment in patients with DR. The pathogenesis of DME is complex, involving numerous risk factors. Recent studies have increasingly revealed that the occurrence and development of DME represents an intertwined pathophysiological process involving metabolic disorders, disruption of the blood-retinal barrier, amplified inflammatory responses, hemodynamic alterations, and the formation of hypoxic microenvironments. Multiple risk factors, including hyperglycaemia, dyslipidaemia, and genetic factors, synergistically drive this process. Risk factors and pathogenesis are a dynamic, interactive relationship in the progression of disease. Comprehensive management of risk factors such as blood glucose and blood lipids, along with multi-target interventions on core pathogenic mechanisms—such as combined anti-vascular endothelial growth factor(VEGF)and anti-inflammatory treatments, exploration of gene therapy and regulation of metabolic pathways—are expected to become key strategies for delaying the progression of DME.

ObjectiveTo observe the clinical effectiveness and safety of Xiaozhong Zhitong Mixture （消肿止痛合剂） combined with antibiotic bone cement in the treatment of diabetic foot ulcer （DFU） with damp-heat obstructing syndrome. MethodsA total of 72 DFU patients with damp-heat obstructing syndrome were randomly assigned to treatment group （36 cases） and the control group （36 cases）. Both groups received standard treatment and topical antibiotic bone cement for ulcer wounds， while the treatment group received oral Xiaozhong Zhitong Mixture （50 ml per time， three times daily） in additionally. Both groups underwent daily wound dressing changes for 21 consecutive days. Ulcer healing rate， serum levels of tumor necrosis factor-alpha （TNF-α）， interleukin-1 beta （IL-1β）， malondialdehyde （MDA）， superoxide dismutase （SOD）， C-reactive protein （CRP）， and white blood cell （WBC） count were observed before and after treatment， and visual analog scale （VAS） scores for wound pain， traditional Chinese medicine （TCM） syndrome scores， and the DFU Healing Scale （DMIST scale） were also compared. Liver and kidney function were evaluated before and after treatment， and adverse events such as allergic reactions， worsening ulcer pain were recorded. ResultsTotally 35 patients in the treatment group and 33 in the control group were included in the final analysis. The ulcer healing rate in the treatment group was （87.93±9.34）%， significantly higher than （81.82±12.02）% in the control group （P = 0.035）. Compared to pre-treatment levels， both groups showed significant reductions in serum CRP， WBC， MDA， IL-1β， and TNF-α levels， with an increase in SOD level （P＜0.05）. TCM syndrome scores， VAS， and DMIST scores also significantly decreased in both groups （P＜0.05）， with greater improvements in the treatment group （P＜0.05）. No significant adverse reactions were observed in either group during treatment. ConclusionXiaozhong Zhitong Mixture combined with antibiotic bone cement has significant advantages in promoting DFU healing， reducing inflammatory response， and alleviating oxidative stress in DFU patients with damp-heat obstructing syndrome， with good safety for DFU patients with damp-heat obstructing syndrome.

Thyroid-associated ophthalmopathy(TAO), the most common orbital disease in adults, is characterized by a rising incidence globally. TAO typically presents with clinical features such as proptosis, upper eyelid retraction, ocular motility dysfunction, and diplopia. Additionally, it significantly compromises the integrity of ocular surface structures, leading to symptoms including dryness, foreign body sensation, photophobia and epiphora, which severely impair patients' visual function and quality of life. Recent studies have increasingly highlighted the roles of ocular surface inflammation, immune dysregulation and ocular surface exposure in the pathogenesis of TAO-related ocular surface damage. These factors collectively contribute to pathological changes in ocular surface structures, such as the conjunctiva, cornea, lacrimal gland and meibomian glands. This review comprehensively summarizes the latest research progress on ocular surface structural damage in TAO patients, aiming to provide a theoretical foundation and novel insights for the early diagnosis, disease evaluation and individualized treatment of TAO.

Objective:To explore the morphological characteristics of the corpus callosum (CC) in patients with unilateral medial temporal lobe epilepsy (mTLE) with hippocampal sclerosis (HS), and their correlation with hippocampal volume and clinical indicators.Methods:This was a cross-sectional study. Clinical (age of onset, disease duration, seizure frequency, seizure duration, etc.) and imaging data of 44 patients mTLE with unilateral HS confirmed by postoperative pathology and 42 healthy controls (HCs) recruited at West China Hospital of Sichuan University from June 2017 to May 2023 were analyzed retrospectively. Among the 44 patients, 19 had left-sided HS and 25 had right-sided HS. All subjects underwent high-resolution 3D T 1WI. Hippocampal volumes were obtained using FreeSurfer. ART was used to measure the morphological parameters of the CC for each participant, including total CC area, volume, perimeter, length, thickness, circularity, and the area of seven CC subregions defined by Witelson: rostrum, genu, body, anterior midbody, posterior midbody, isthmus and splenium. Differences in these metrics between two or three groups were compared using independent samples t-test or one-way ANOVA. Pearson or Spearman correlation analysis was used to observe the correlation between morphological features of the CC and hippocampal volume and other clinical indicators in patients with mTLE with unilateral HS. Results:Compared with HCs, patients with mTLE with unilateral HS had significantly reduced total CC area, CC circularity, as well as the area and thickness of the genu, anterior midbody, posterior midbody, isthmus, splenium, and the area of the rostrum ( P<0.05). Significant differences were observed in the total area, circularity, and subregional areas (genu, rostrum, anterior midbody, posterior midbody, splenium), as well as thickness (genu, anterior midbody, posterior midbody, isthmus) of the CC among mTLE with left-sided HS, mTLE with right-sided HS, and HCs ( P<0.05). When compared to HCs, the total area of the CC, circularity and the areas of the genu, rostrum, anterior midbody, posterior midbody, and splenium, and the thicknesses of the genu, anterior midbody, posterior midbody, and isthmus of the CC were significantly reduced in patients with mTLE with right-sided HS ( P<0.05), and the thicknesses of the midbody and isthmus of the CC were significantly reduced in patients with mTLE with left-sided HS compared to HCs ( P<0.05), and the two-by-two comparison of the rest of the indicators did not show statistically significant differences ( P>0.05). Correlation analysis showed that some morphological abnormalities in the CC in mTLE with unilateral HS patients were significantly correlated with age of onset, disease duration, seizure frequency, seizure duration, and hippocampal volume. Conclusions:mTLE with unilateral HS patients can exhibit morphological abnormalities in the CC, particularly in those with right-sided lesions. These abnormalities are significantly associated with seizure-related factors and hippocampal atrophy.

Objective:To investigate the imaging characteristics of small intestinal epithe-lioid angiosarcoma.Methods:The retrospective and descriptive study was conducted. The clinical data of 5 male patients with small intestinal epithelioid angiosarcoma who were admitted to 3 medical centers, including Yantaishan Hospital of Yantai et al, from January 2013 to December 2023 were collected. The age of 5 patients was 54 (range, 36-73)years. All 5 patients underwent computer tomography (CT) plain scan and dynamic contrast-enhanced scan, with 1 patient also undergoing magnetic resonance imaging (MRI) plain scan. Observation indicators: (1) results of CT and MRI examination; (2) surgical conditions and postoperative pathological examination; (3) follow-up. Measurement data with skewed distribution were represented as M(range), and count data were described as absolute numbers. Results:(1) Results of CT and MRI examination. Of the 5 patients with small intestinal epithelioid angiosarcoma, two cases were primary small intestinal epithelioid angiosarcoma and the other three cases were metastatic small intestinal epithelioid angiosarcoma. None of the five patients exhibited metastasis to other solid organs, and no significant ascites or peritoneal metastases. ① In two cases of primary small intestinal epithelioid angiosarcoma, three tumors were identified, appearing as round soft tissue nodules on CT plain scan, primarily growing intraluminally. The CT value for tumors of those two cases on plain scan were 30, 35, 32 HU, respec-tively. During the arterial phase of enhanced CT scan, moderate enhancement was observed for tumors of those two cases, with CT value of 57, 72, 65 HU, respectively. During the venous phase of enhanced CT scan, significant enhancement was observed for tumors of those two cases, with CT value of 76, 86, 88 HU, respectively. During the delayed phase of enhanced CT scan, slightly decreased enhancement was observed for tumors of those two cases, with CT value of 74, 79, 72 HU, showing no significant necrosis or cystic changes within the tumors. ② In three cases of metastatic small intestinal epithelioid angiosarcoma, four tumors were identified with uneven thickening of the intestinal wall appeared on CT plain scan. The CT value for tumors of those three cases on plain scan were 39, 37, 38, 28 HU, respectively. During the arterial phase of enhanced CT scan, mild to moderate enhancement was observed for tumors of those three cases, with CT value of 57, 56, 52, 45 HU, respectively. During the venous phase of enhanced CT scan, significant enhancement was observed for tumors of those three cases, with CT value of 84, 88, 82, 77 HU, respectively. During the delayed phase of enhanced CT scan, further changes of increased or decreased enhancement was observed for tumors of those three cases, with CT value of 95, 78, 72, 70 HU. One case of those three patients had thickened intestinal wall with low signal on T1-weighted imaging, heterogeneous high signal on fat-suppressed T2-weighted imaging, significant high signal on diffusion-weighted imaging and low signal on apparent diffusion coefficient imaging on MRI scan. (2) Surgical conditions and post-operative pathological examination. All five cases underwent complete tumor resection. In two cases of primary epithelioid angiosarcoma with three small intestinal tumor foci, there were two tumors invading the serosa and one tumor invading the submucosa. All three metastatic epithelioid angio-sarcoma cases showed four tumors invasion through the serosa, with one case exhibiting mesenteric lymph node metastasis. Microscopic examination revealed hemorrhagic necrosis on the tumor mucosal surface, with tumor cells located in the submucosa or throughout the intestinal wall, displaying infiltrative growth patterns. The distribution was diffuse, with local networks forming irregularly sized vascular-like structures, containing red blood cells and forming blood sinuses and vascular networks. Tumor cells were arranged in solid sheets, strands, and nests, exhibiting spindle-shaped or epithelioid characteristics, with marked atypia, large nuclei, prominent nucleoli, and mitotic figures. Immunohistochemical analysis showed diffuse strong positivity for CD31, Fli-1, and Vim in all five patients. (3) Follow-up. All five patients were followed up postoperatively for 6(range, 3?48)months. During the follow-up period, four patients succumbed to widespread metastasis. One patient with metastatic small intestinal epithelioid angiosarcoma underwent six cycles of chemotherapy and remained in good condition four years post-surgery.Conclusion:The imaging characteristics of small intestinal epithelioid angiosarcoma include abnormal thickening or masses of the intestinal wall.

Objective:To investigate the imaging characteristics of small intestinal epithe-lioid angiosarcoma.Methods:The retrospective and descriptive study was conducted. The clinical data of 5 male patients with small intestinal epithelioid angiosarcoma who were admitted to 3 medical centers, including Yantaishan Hospital of Yantai et al, from January 2013 to December 2023 were collected. The age of 5 patients was 54 (range, 36-73)years. All 5 patients underwent computer tomography (CT) plain scan and dynamic contrast-enhanced scan, with 1 patient also undergoing magnetic resonance imaging (MRI) plain scan. Observation indicators: (1) results of CT and MRI examination; (2) surgical conditions and postoperative pathological examination; (3) follow-up. Measurement data with skewed distribution were represented as M(range), and count data were described as absolute numbers. Results:(1) Results of CT and MRI examination. Of the 5 patients with small intestinal epithelioid angiosarcoma, two cases were primary small intestinal epithelioid angiosarcoma and the other three cases were metastatic small intestinal epithelioid angiosarcoma. None of the five patients exhibited metastasis to other solid organs, and no significant ascites or peritoneal metastases. ① In two cases of primary small intestinal epithelioid angiosarcoma, three tumors were identified, appearing as round soft tissue nodules on CT plain scan, primarily growing intraluminally. The CT value for tumors of those two cases on plain scan were 30, 35, 32 HU, respec-tively. During the arterial phase of enhanced CT scan, moderate enhancement was observed for tumors of those two cases, with CT value of 57, 72, 65 HU, respectively. During the venous phase of enhanced CT scan, significant enhancement was observed for tumors of those two cases, with CT value of 76, 86, 88 HU, respectively. During the delayed phase of enhanced CT scan, slightly decreased enhancement was observed for tumors of those two cases, with CT value of 74, 79, 72 HU, showing no significant necrosis or cystic changes within the tumors. ② In three cases of metastatic small intestinal epithelioid angiosarcoma, four tumors were identified with uneven thickening of the intestinal wall appeared on CT plain scan. The CT value for tumors of those three cases on plain scan were 39, 37, 38, 28 HU, respectively. During the arterial phase of enhanced CT scan, mild to moderate enhancement was observed for tumors of those three cases, with CT value of 57, 56, 52, 45 HU, respectively. During the venous phase of enhanced CT scan, significant enhancement was observed for tumors of those three cases, with CT value of 84, 88, 82, 77 HU, respectively. During the delayed phase of enhanced CT scan, further changes of increased or decreased enhancement was observed for tumors of those three cases, with CT value of 95, 78, 72, 70 HU. One case of those three patients had thickened intestinal wall with low signal on T1-weighted imaging, heterogeneous high signal on fat-suppressed T2-weighted imaging, significant high signal on diffusion-weighted imaging and low signal on apparent diffusion coefficient imaging on MRI scan. (2) Surgical conditions and post-operative pathological examination. All five cases underwent complete tumor resection. In two cases of primary epithelioid angiosarcoma with three small intestinal tumor foci, there were two tumors invading the serosa and one tumor invading the submucosa. All three metastatic epithelioid angio-sarcoma cases showed four tumors invasion through the serosa, with one case exhibiting mesenteric lymph node metastasis. Microscopic examination revealed hemorrhagic necrosis on the tumor mucosal surface, with tumor cells located in the submucosa or throughout the intestinal wall, displaying infiltrative growth patterns. The distribution was diffuse, with local networks forming irregularly sized vascular-like structures, containing red blood cells and forming blood sinuses and vascular networks. Tumor cells were arranged in solid sheets, strands, and nests, exhibiting spindle-shaped or epithelioid characteristics, with marked atypia, large nuclei, prominent nucleoli, and mitotic figures. Immunohistochemical analysis showed diffuse strong positivity for CD31, Fli-1, and Vim in all five patients. (3) Follow-up. All five patients were followed up postoperatively for 6(range, 3?48)months. During the follow-up period, four patients succumbed to widespread metastasis. One patient with metastatic small intestinal epithelioid angiosarcoma underwent six cycles of chemotherapy and remained in good condition four years post-surgery.Conclusion:The imaging characteristics of small intestinal epithelioid angiosarcoma include abnormal thickening or masses of the intestinal wall.

Objective:To explore the morphological characteristics of the corpus callosum (CC) in patients with unilateral medial temporal lobe epilepsy (mTLE) with hippocampal sclerosis (HS), and their correlation with hippocampal volume and clinical indicators.Methods:This was a cross-sectional study. Clinical (age of onset, disease duration, seizure frequency, seizure duration, etc.) and imaging data of 44 patients mTLE with unilateral HS confirmed by postoperative pathology and 42 healthy controls (HCs) recruited at West China Hospital of Sichuan University from June 2017 to May 2023 were analyzed retrospectively. Among the 44 patients, 19 had left-sided HS and 25 had right-sided HS. All subjects underwent high-resolution 3D T 1WI. Hippocampal volumes were obtained using FreeSurfer. ART was used to measure the morphological parameters of the CC for each participant, including total CC area, volume, perimeter, length, thickness, circularity, and the area of seven CC subregions defined by Witelson: rostrum, genu, body, anterior midbody, posterior midbody, isthmus and splenium. Differences in these metrics between two or three groups were compared using independent samples t-test or one-way ANOVA. Pearson or Spearman correlation analysis was used to observe the correlation between morphological features of the CC and hippocampal volume and other clinical indicators in patients with mTLE with unilateral HS. Results:Compared with HCs, patients with mTLE with unilateral HS had significantly reduced total CC area, CC circularity, as well as the area and thickness of the genu, anterior midbody, posterior midbody, isthmus, splenium, and the area of the rostrum ( P<0.05). Significant differences were observed in the total area, circularity, and subregional areas (genu, rostrum, anterior midbody, posterior midbody, splenium), as well as thickness (genu, anterior midbody, posterior midbody, isthmus) of the CC among mTLE with left-sided HS, mTLE with right-sided HS, and HCs ( P<0.05). When compared to HCs, the total area of the CC, circularity and the areas of the genu, rostrum, anterior midbody, posterior midbody, and splenium, and the thicknesses of the genu, anterior midbody, posterior midbody, and isthmus of the CC were significantly reduced in patients with mTLE with right-sided HS ( P<0.05), and the thicknesses of the midbody and isthmus of the CC were significantly reduced in patients with mTLE with left-sided HS compared to HCs ( P<0.05), and the two-by-two comparison of the rest of the indicators did not show statistically significant differences ( P>0.05). Correlation analysis showed that some morphological abnormalities in the CC in mTLE with unilateral HS patients were significantly correlated with age of onset, disease duration, seizure frequency, seizure duration, and hippocampal volume. Conclusions:mTLE with unilateral HS patients can exhibit morphological abnormalities in the CC, particularly in those with right-sided lesions. These abnormalities are significantly associated with seizure-related factors and hippocampal atrophy.

Objective:To explore the clinical data of patients with metastatic pheochromocytoma/paraganglioma (PPGL).Methods:The clinical data of 57 patients with metastatic pheochromocytoma/paraganglioma diagnosed and treated at Peking Union Medical College Hospital from January 2016 to June 2022 were reviewed, including 28 cases of pheochromocytoma(PCC) and 29 cases of paraganglioma(PGL). The clinical manifestations, biochemical indexes, tumour characteristics, and metastatic characteristics of the 57 patients were analysed.Results:There were 34 males and 23 females. The median age at the time of initial diagnosis was 34 (20, 54) years, 17 (29.3%) presented with concurrent metastases, and 40 (70.7%) with heterochronous metastases. The median time to presentation of metastases was 2.2 (0, 5.0) years (range 0-22 years). Adrenergic symptoms were present in 45 cases (78.6%) at the time of initial diagnosis, and the median size of the primary tumour was 6.7 (5.0, 9.0) cm. Excessive catecholamine secretion was present in 48 cases (81.4%). The most common locations of metastasis were lymph nodes (71.9%, 41/57), bone (47.3%, 27/57), lung (38.6%, 20/57), and liver (35.1%, 20/57). Metastatic PGL had more multifocal metastases than PCC [10 (34.5%) vs. 2 (7.1%), P=0.011)], was more frequently associated with SDHB mutations [13 (42.9%) vs. 3 (10.7%), P=0.008], and was more likely to have concurrent metastases [12 (41.3%) vs. 5 (17.9%), P=0.005]. Metastatic PCC primary tumours were larger compared to PGL [median length 8.9 (4.0, 17.0) cm vs. 6.1 (1.0, 15.8) cm, P=0.020]. Conclusions:Patients with PGL present with metastases over an extremely wide time span, and patients diagnosed with PPGL should be followed throughout their lives. PGL is more prone to multifocal metastases and simultaneous metastases than PCC, and PGL is more highly correlated with the SDHB mutation.

Objective To explore the mechanism of Nuanxinkang Powder(aka.NXK,composed of Ginseng Radix et Rhizoma Rubra and Ilex Pubescens Radix)on improving ventricular remodeling in post-infarction mice based on the"metabolic-inflammatory"network regulating macrophage polarization.Methods ①Thirty C57BL/6J male mice were randomly divided into three groups:sham-operation group,model group,and NXK group(1.65 g·kg-1),with 10 mice in each group;the mouse model of myocardial infarction was replicated using left anterior descending coronary artery ligation;and the drug was administered by gavage once a day for 4 consecutive weeks.Masson staining was used to detect collagen deposition in myocardial tissue;ultrasound was used to detect cardiac function in mice:left ventricular ejection fraction(LVEF),left ventricular anterior wall thickness at end-systole(LVAWS)and left ventricular anterior wall thickness at end-diastole(LVAWD);flow cytometry was used to detect distribution of cardiac macrophages in mice;qPCR was used to detect mRNA expressions of lactate dehydrogenase A(LDHA),carnitine palmitoyltransferase 1(CPT-1),glucose transport protein 4(GLUT4),isocitrate dehydrogenase(IDH),and succinate dehydrogenase(SDHa)in heart tissue.②NXK was given 1.15 g·kg-1 NXK suspension to rats by gavage twice a day for 5 consecutive days to prepare NXK-containing serum.Lipopolysaccharide(LPS)-induced RAW 264.7 cells were used to construct a pro-inflammatory macrophage model.The cells were grouped into the following groups:blank serum control group(medium containing 5%blank serum+5%fetal bovine serum),NXK drug-containing serum group(medium containing 5%NXK drug-containing serum+5%fetal bovine serum),lipopolysaccharide group(medium containing 5%blank serum+5%fetal bovine serum+200 μg·mL-1 lipopolysaccharide),NXK drug-containing serum+ lipopolysaccharide group(medium containing 5%NXK drug-containing serum+5%fetal bovine serum+200 μ g·mL-1 lipopolysaccharide),all the groups were intervened for 16 hours.Glycolysis stress test was used to detect the level of glycolysis in RAW 264.7 cells;qPCR was used to detect the mRNA expression of mitochondrial pyruvate carrier(MPC1)in RAW 264.7 cells;and MitoSox Red fluorescent staining was used to detect the level of oxidative stress damage in mitochondria of RAW 264.7 cells.Results ①Compared with the sham-operation group,the blue-stained area of cardiac collagen fibres in mice of the model group was significantly increased,accompanied by thinning of the ventricular wall and enlargement of the left ventricular cavity;cardiac function indexes,such as LVEF,LVAWS,LVAWD,etc.,were all significantly reduced(P＜0.01,P＜0.001);the mRNA expressions of LDHA and CPT-1 were significantly up-regulated in the cardiac tissues of mice(P＜0.05),and the mRNA expressions of GLUT4,IDH and SDHa were significantly down-regulated(P＜0.05,P＜0.01),and CD86 staining positive cell was significantly increased(P＜0.001).Compared with the model group,mice in the NXK group showed a significant decrease in cardiac collagen fiber deposition and an increase in the thickness of the ventricular wall;cardiac function indexes such as LVEF,LVAWS and LVAWD were significantly increased(P＜0.05,P＜0.01,P＜0.001);and the mRNA expressions of LDHA and CPT-1 in the cardiac tissues of the mice were significantly down-regulated(P＜0.01,P＜0.001),mRNA expressions of GLUT4,SDHa and IDH were significantly up-regulated(P＜0.01),and the number of CD86 positive cells was significantly reduced(P＜0.001).②Compared with the blank serum control group,the cytosolic glycolysis level and ROS level of macrophages in the NXK serum-containing group did not change significantly(P＞0.05),whereas the glycolysis level and ROS level of macrophages in the lipopolysaccharide group were significantly increased(P＜0.01),and the mRNA expression of MPC1 was significantly down-regulated(P＜0.001).Compared with the lipopolysaccharide group,the macrophage glycolysis level and ROS level were significantly reduced in the NXK serum-containing + lipopolysaccharide group(P＜0.05,P＜0.01),and mRNA expression of MPC1 was significantly up-regulated(P＜0.001).Conclusion NXK can reduce myocardial fibrosis and ventricular remodeling after myocardial infarction and improve cardiac function in mice,and its mechanism may be related to the down-regulation of mRNA expression of LDHA in cardiac tissues,the up-regulation of mRNA expression of GLUT4,the improvement of cardiac glucose uptake after myocardial infarction,the inhibition of pro-inflammatory macrophage glycolysis,the increase in the expressions of SDHa and IDH to alleviate the accumulation of succinate and citrate,and the reduction of reactive oxygen species(ROS)generation,thereby reducing pro-inflammatory macrophage hyperpolarisation.

Retinal vein occlusion(RVO)is the second most common cause of vision loss due to retinal vascular disease. Macular edema(ME)is a common complication of RVO and a major cause of central vision impairment. Optical coherence tomography(OCT)is a high-resolution imaging technique that can provide detailed cross-sectional images of the retina and choroid. OCT biomarkers play an important role in the early and accurate diagnosis of RVO-ME, prediction of disease progression, and assessment of visual prognosis. This article provides an overview of various OCT biomarkers for RVO-ME, including retinal thickness, disorganization of retinal inner layers, hyper-reflectivity of retinal inner layer, the integrity of external limiting membrane and ellipsoid zone, the third highest reflectance band of the fovea, hyperreflective dots, paracentral acute middle maculopathy, prominent middle limiting membrane sign, serous retinal detachment height, macular volume and choroidal thickness. These biomarkers serve as objective indicators for evaluating the severity of RVO-ME, guiding treatment decisions, and predicting visual outcomes.