Identification of genomic regions controlling spikelet degeneration under FRIZZLE PANICLE (FZP) defect genetic background in rice.

The FZP gene plays a critical role in the formation of lateral branches and spikelets in rice panicle architecture. This study investigates the qSBN7 allele, a hypomorphic variant of FZP, and its influence on panicle architectures in different genetic backgrounds. We evaluated two backcross inbred lines (BILs), BC5_TCS10sbn and BC3_TCS10sbn, each possessing the homozygous qSBN7 allele but demonstrating differing degrees of spikelet degeneration. Our analysis revealed that BC5_TCS10sbn had markedly low FZP expression, which corresponded with an increase in axillary branches and severe spikelet degeneration. Conversely, BC3_TCS10sbn exhibited significantly elevated FZP expression, leading to fewer secondary and tertiary branches, and consequently decreased spikelet degeneration. Compared to BC5_TCS10sbn, BC3_TCS10sbn carries three additional chromosomal substitution segments from its donor parent, IR65598-112-2. All three segments significantly enhance the expression of FZP and reduce the occurrence of tertiary branch and spikelet degeneration. These findings enhance our understanding of the mechanisms regulating FZP and aid rice breeding efforts.

Translation, adaptation, and validation of a Chinese version of the Hypertension Self-Care Activity Level effects (H-SCALE) for patients with hypertension.

BACKGROUND: Lifestyle modification is an essential component of prevention and management of hypertension. Existing instruments in Taiwan focus on assessing lifestyle modifications by evaluating medication adherence or confidence in controlling blood pressure. However, other self-care activities, such as diet, physical activity, weight management, smoking, and alcohol consumption are also important. The Hypertension Self-Care Activity Level Effects (H-SCALE) is one such instrument, but there are no similar tools available in Taiwan. AIM: This study aimed to translate the H-SCALE into Chinese and test its validity, and reliability in a sample of adults with hypertension. METHODS: The English version of the 31-item H-SCALE was translated into Chinese using the forward-backward method. The content validity index (CVI) of the translated scale was determined by five experts in hypertension. Item analysis was conducted with a pilot sample of 20 patients with hypertension. Cronbach's α was used to establish the internal consistency reliability for the Chinese version of the H-SCALE (H-SCALE-C). Exploratory factor analysis (EFA) explored the structure of the H-SCALE-C. Additionally, construct validity was examined with confirmatory factor analysis (CFA). Patients with hypertension were recruited by convenience sampling from a cardiovascular outpatient clinic of a medical center in northern Taiwan. A total of 318 patients met the inclusion criteria and participated in factor analysis in the study. RESULTS: Pilot testing of the scale items indicated most patients could not accurately estimate the number of days of alcohol consumption for the previous week. Therefore, three alcohol-related items were removed. The adaptation resulted in a 28-item H-SCALE-C. EFA revealed a 4-factor solution with 13 items that explained 63.93% of the total variance. CFA indicated a good fit for a 4-factor model and construct validity was acceptable. Internal consistency reliability was acceptable (Cronbach's alpha for the four subscales ranged from 0.65 to 0.94). Convergent validity was acceptable, and discriminant validity was significant. CONCLUSIONS: The H-SCALE-C is a valid, reliable tool for promptly assessing life-style activities for patients with hypertension in Taiwan. The instrument is suitable for assisting healthcare providers in evaluating self-care activities, which could be used to facilitate lifestyle modifications for patients with hypertension.

WSSV early protein WSSV004 enhances viral replication by suppressing LDH activity.

White spot syndrome virus (WSSV) is known to upregulate glycolysis to supply biomolecules and energy for the virus's replication. At the viral genome replication stage, lactate dehydrogenase (LDH), a glycolytic enzyme, shows increased activity without any increase in expression. In the present study, yeast 2-hybrid screening was used to identify WSSV proteins that interacted with LvLDH isoform 1 and 2, and these included the WSSV early protein WSSV004. The interaction between WSSV004 and LvLDH1/2 was confirmed by co-immunoprecipitation. Immunofluorescence showed that WSSV004 co-localized with LvLDH1/2 in the cytoplasm. dsRNA silencing experiments showed that WSSV004 was crucial for WSSV replication. However, although WSSV004 silencing led to the suppression of total LvLDH gene expression during the viral late stage, there was nevertheless a significant increase in LvLDH activity at this time. We also used affinity purification-mass spectrometry to identify cellular proteins that interact with WSSV004, and found a total of 108 host proteins and 3 WSSV proteins with which it potentially interacts. Bioinformatics analysis revealed that WSSV004 and its interacting proteins might be responsible for various biological pathways during infection, including vesicular transport machinery and RNA-related functions. Collectively, our study suggests that WSSV004 serves as a multifunctional modulator to facilitate WSSV replication.

The Prognostic Value of D-Dimer in Patients with Acute Myocardial Infarction: A Retrospective Longitudinal Cohort Study in Taiwan.

Background: Serum D-dimer level has been associated with worsening outcomes in patients with acute myocardial infarction. This study aimed to explore the association between serum D-dimer level and clinical outcomes in Taiwanese patients with acute myocardial infarction. Methods: We analyzed Tri-Service General Hospital-Coronary Heart Disease registry data related to patients with acute myocardial infarction who were admitted between January 2014 and December 2018. A total of 748 patients were enrolled and categorized into high (≥ 495 ng/ml) and low (< 495 ng/ml) D-dimer groups. The primary endpoint was in-hospital mortality, and secondary endpoints were post-discharge mortality and post-discharge major adverse cardiovascular events. Results: Overall, 139 patients died, with 77 from cardiovascular causes and 62 from non-cardiovascular causes. In-hospital mortality was higher in the high D-dimer group than in the low D-dimer group. Among the patients alive at discharge, those with a high D-dimer level had higher cardiovascular mortality and future major adverse cardiovascular events than those with a low D-dimer level. Multivariate Cox regression analysis revealed that higher serum D-dimer levels were significantly associated with higher risks of in-hospital mortality [hazard ratio (HR) = 1.11; 95% confidence interval (CI), 1.06-1.16, p < 0.001], subsequent cardiovascular mortality after discharge (HR = 1.15; 95% CI, 1.08-1.22, p < 0.001), and major adverse cardiovascular events (HR = 1.10; 95% CI, 1.04-1.16, p < 0.001). Conclusions: This is the first study in Taiwan to demonstrate that a higher baseline serum D-dimer level was independently associated with higher risks of in-hospital mortality, post-discharge mortality, and major adverse cardiovascular events in patients with acute myocardial infarction.

Licochalcone D ameliorates lipid metabolism in hepatocytes by modulating lipogenesis and autophagy.

Metabolic dysfunction-associated fatty liver disease is a metabolic disease caused by abnormal lipid accumulation in the liver. Excessive lipid accumulation results in liver inflammation and fibrosis. Previous studies have demonstrated that the chalcone licochalcone D, which is isolated from Glycyrrhiza inflata Batal, has anti-tumor and anti-inflammatory effects. The present study explored whether licochalcone D can regulate lipid accumulation in fatty liver cells. FL83B hepatocytes were incubated with oleic acid to establish a fatty liver cell model, and then treated with licochalcone D to evaluate the molecular mechanisms underlying the regulation of lipid metabolism. In addition, male C57BL/6 mice were fed a methionine/choline-deficient diet to induce an animal model of metabolic dysfunction-associated steatohepatitis (MASH) and given 5 mg/kg licochalcone D by intraperitoneal injection. In cell experiments, licochalcone D significantly reduced lipid accumulation in fatty liver cells and reduced sterol regulatory element-binding protein 1c expression, blocking fatty acid synthase production. Licochalcone D increased adipose triglyceride lipase and carnitine palmitoyltransferase 1 expression, enhancing lipolysis and fatty acid ß-oxidation, respectively. Licochalcone D also significantly increased SIRT-1 and AMPK phosphorylation, reducing acetyl-CoA carboxylase phosphorylation and inhibiting fatty acid synthesis. Licochalcone D also increased the fusion of autophagosomes and lysosomes to promote autophagy, reducing oil droplet accumulation in fatty liver cells. In the animal experiments, licochalcone D effectively reduced the number of lipid vacuoles and degree of fibrosis in liver tissue and inhibited liver inflammation. Thus, licochalcone D can improve MASH by reducing lipid accumulation, inhibiting inflammation, and increasing autophagy.

Lead Isolation and Capture in Perovskite Photovoltaics toward Eco-Friendly Commercialization.

Perovskite solar cells (PSCs) are developed rapidly in efficiency and stability in recent years, which can compete with silicon solar cells. However, an important obstacle to the commercialization of PSCs is the toxicity of lead ions (Pb2+) from water-soluble perovskites. The entry of free Pb2+ into organisms can cause severe harm to humans, such as blood lead poisoning, organ failure, etc. Therefore, this work reports a "lead isolation-capture" dual detoxification strategy with calcium disodium edetate (EDTA Na-Ca), which can inhibit lead leakage from PSCs under extreme conditions. More importantly, leaked lead exists in a nontoxic aggregation state chelated by EDTA. For the first time, in vivo experiments are conducted in mice to systematically prove that this material has a significant inhibitory effect on the toxicity of perovskites. In addition, this strategy can further enhance device performance, enabling the optimized devices to achieve an impressive power conversion efficiency (PCE) of 25.19%. This innovative strategy is a major breakthrough in the research on the prevention of lead toxicity in PSCs.

Prognostic and Immunotherapeutic Predictive Value of CAD Gene in Hepatocellular Carcinoma: Integrated Bioinformatics and Experimental Analysis.

Hepatocellular carcinoma (HCC) is a common type of cancer that ranks first in cancer-associated death worldwide. Carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase (CAD) are the key components of the pyrimidine pathway, which promotes cancer development. However, the function of CAD in HCC needs to be clarified. In this study, the clinical and transcriptome data of 424 TCGA-derived HCC cases were analyzed. The results demonstrated that high CAD expression was associated with poor prognosis in HCC patients. The effect of CAD on HCC was then investigated comprehensively using GO annotation analysis, KEGG enrichment analysis, Gene Set Enrichment Analysis (GSEA), and CIBERSORT algorithm. The results showed that CAD expression was correlated with immune checkpoint inhibitors and immune cell infiltration. In addition, low CAD levels in HCC patients predicted increased sensitivity to anti-CTLA4 and PD1, while HCC patients with high CAD expression exhibited high sensitivity to chemotherapeutic and molecular-targeted agents, including gemcitabine, paclitaxel, and sorafenib. Finally, the results from clinical sample suggested that CAD expression increased remarkably in HCC compared with non-cancerous tissues. Loss of function experiments demonstrated that CAD knockdown could significantly inhibit HCC cell growth and migration both in vitro and in vivo. Collectively, the results indicated that CAD is a potential oncogene during HCC metastasis and progression. Therefore, CAD is recommended as a candidate marker and target for HCC prediction and treatment.

Mediating Effect of Heart Rate Variability on the Relationship Between Anxiety Symptoms and Blood Pressure in Patients with Primary Hypertension.

Patients with hypertension (HTN) are at increased risk of developing cardiovascular disease, which can be reduced with blood pressure (BP) control. Anxiety can contribute to high BP and low heart rate variability (HRV). Although relationships between social support, self-rated health-status (SRHS), anxiety and measures of HRV and BP have been suggested, they have not been clearly established. This cross-sectional correlational study aimed to 1) examine relationships between social support, SRHS, and anxiety; and 2) examine if HRV mediated relationships between anxiety symptoms and BP. Patients with primary HTN were recruited from a cardiovascular outpatient clinic using convenience sampling (N = 300). Data included scale scores for SRHS, social support, and anxiety (Hospital Anxiety and Depression Scale). A handheld limb-lead electrocardiogram monitor measured HRV, using the ratio of low-frequency bands to high-frequency bands; an automatic sphygmomanometer measured systolic and diastolic blood pressure (SBP and DBP, respectively). Path analysis of structural equation models examined relationships between variables; the bootstrap method examined the mediating effects of HRV. Analysis showed scores for SRHS and social support had a direct effect on anxiety scores. Scores for anxiety directly affected HRV and BP. HRV also had a direct effect on BP. Bootstrapping indicated HRV mediated the relationship between anxiety symptoms and BP. The final model indicated SRHS, social support, and anxiety symptoms together explained 80% of SBP and 33% of DBP. These findings suggest HRV could be used to measure the effectiveness of strategies aimed at reducing anxiety and improving control of BP.

Mitomycin C and its analog trigger cytotoxicity in MCF-7 and K562 cancer cells through the regulation of RAS and MAPK/ERK pathways.

Mitomycin C (MC) is an anti-cancer drug which functions by forming interstrand crosslinks (ICLs) between opposing DNA strands. MC analog, 10-decarbamoyl mitomycin C (DMC), unlike MC, has stronger cytotoxic effects on cancer cells with TP53 mutation. We previously demonstrated that MC/DMC could activate p21WAF1/CIP1 in MCF-7 (TP53-proficient) and K562 (TP53 deficient) cells in a TP53-independent mode. We also found that MC/DMC regulate AKT activation in a TP53-dependent manner and that AKT deactivation is not associated with the activation of p21WAF1/CIP1 in response to MC/DMC treatment. RAS proteins are known players in the upstream mediated signaling of p21WAF1/CIP1 activation that leads to control of cell proliferation and cell death. Thus, this prompted us to investigate the effect of both drugs on the expression of RAS proteins and regulation of the MAPK/ERK signaling pathways in MCF-7 and K562 cancer cells. To accomplish this goal, we performed comparative label free proteomics profiling coupled to bioinformatics/complementary phosphoprotein arrays and Western blot validations of key signaling molecules. The MAPK/ERK pathway exhibited an overall downregulation upon MC/DMC treatment in MCF-7 cells but only DMC exhibited a mild downregulation of that same pathway in TP53 mutant K562 cells. Furthermore, treatment of MCF-7 and K562 cell lines with oligonucleotides containing the interstrand crosslinks (ICLs) formed by MC or DMC shows that both ICLs had a stronger effect on the downregulation of RAS protein expression in mutant TP53 K562 cells. We discuss the implication of this regulation of the MAPK/ERK pathway in relation to cellular TP53 status.

The A subunit of vacuolar H+-ATPase gene (CmVHA-A) plays opposite roles in plant growth and drought tolerance of chrysanthemum under different growing conditions.

As the most prominent proton pumps in plants, vacuolar H+-ATPases (VHAs) comprise multiple subunits that are important for physiological processes and stress tolerance in plants. However, few studies on the roles of subunit genes of VHAs in chrysanthemum have been reported to date. In this study, the gene of A subunit of V-ATPase in chrysanthemum (CmVHA-A) was cloned and identified. CmVHA-A was conserved with VHA-A proteins from other plants. Expression analysis showed that CmVHA-A was highly expressed in most tissues of chrysanthemum except for the flower bud, and was readily induced by polyethylene glycol (PEG) treatment. Functional analysis demonstrated that CmVHA-A exerted a negative influence on the growth and development of shoot and root of chrysanthemum under normal conditions. RNA-sequencing (RNA-seq) analysis revealed the possible explanations for phenotypic differences between transgenic and wild-type (WT) plants. Under drought conditions, CmVHA-A positively affected the drought tolerance of chrysanthemum by enhancing antioxidase activity and alleviating photosynthetic disruption. Overall, CmVHA-A plays opposite roles in plant growth and drought tolerance of chrysanthemums under different growing conditions.

Anti-metabolic agent pegaspargase plus PD-1 antibody sintilimab for first-line treatment in advanced natural killer T cell lymphoma.

Natural killer T cell lymphoma (NKTCL) is highly aggressive, with advanced stage patients poorly responding to intensive chemotherapy. To explore effective and safe treatment for newly diagnosed advanced stage NKTCL, we conducted a phase II study of anti-metabolic agent pegaspargase plus PD-1 antibody sintilimab (NCT04096690). Twenty-two patients with a median age of 51 years (range, 24-74) were enrolled and treated with induction treatment of pegaspargase 2500 IU/m2 intramuscularly on day 1 and sintilimab 200 mg intravenously on day 2 for 6 cycles of 21 days, followed by maintenance treatment of sintilimab 200 mg for 28 cycles of 21 days. The complete response and overall response rate after induction treatment were 59% (95%CI, 43-79%) and 68% (95%CI, 47-84%), respectively. With a median follow-up of 30 months, the 2 year progression-free and overall survival rates were 68% (95%CI, 45-83%) and 86% (95%CI, 63-95%), respectively. The most frequently grade 3/4 adverse events were neutropenia (32%, n = 7) and hypofibrinogenemia (18%, n = 4), which were manageable and led to no discontinuation of treatment. Tumor proportion score of PD-L1, peripheral blood high-density lipoprotein cholesterol, and apolipoprotein A-I correlated with good response, while PD-1 on tumor infiltrating lymphocytes and peripheral Treg cells with poor response to pegaspargase plus sintilimab treatment. In conclusion, the chemo-free regimen pegaspargase plus sintilimab was effective and safe in newly diagnosed, advanced stage NKTCL. Dysregulated lipid profile and immunosuppressive signature contributed to treatment resistance, providing an alternative therapeutic approach dual targeting fatty acid metabolism and CTLA-4 in NKTCL.

An inferior vena cava-priority approach in laparoscopic isolated hepatic caudate lobectomy.

PURPOSE: Laparoscopic isolated caudate lobectomy is still a challenging operation for surgeons. The access route of the operation plays a vital role during laparoscopic caudate lobectomy. There are few references regarding this technique. Here, we introduce a preferred inferior vena cava (IVC) approach in laparoscopic caudate lobectomy. METHODS: Twenty-one consecutive patients with caudate hepatic tumours between June 2016 and December 2021 were included in this study. All of them received laparoscopic caudate lobectomy involving an IVC priority approach. The IVC priority approach refers to prioritizing the dissection of the IVC from the liver parenchyma before proceeding with the conventional left or right approach. It emphasizes the importance of the IVC dissection during process. Clinical data, intraoperative parameters and postoperative results were evaluated. Sixteen patients were performed pure IVC priority approach, while 5 patients underwent a combined approach. We subsequently compared the intraoperative and postoperative between the two groups. RESULTS: All 21 patients were treated with laparoscopic technology. The operative time was 190.95 ± 92.65 min. The average estimated blood loss was 251.43 ± 247.45 ml, and four patients needed blood transfusions during the perioperative period. The average duration of hospital stay was 8.43 ± 2.64 (range from 6.0 to 16.0) days. Patients who underwent the pure inferior vena cava (IVC) approach required a shorter hepatic pedicle clamping time (26 vs. 55 min, respectively; P < 0.001) and operation time (150 vs. 380 min, respectively; P = 0.002) than those who underwent the combined approach. Hospitalization (7.0 vs. 9.0 days, respectively; P = 0.006) was shorter in the pure IVC group than in the combined group. CONCLUSIONS: Laparoscopic caudate lobectomy with an IVC priority approach is safe and feasible for patients with caudate hepatic tumours.

Development of the Low-Temperature Inducible System for Recombinant Protein Production in Escherichia coli Nissle 1917.

The pET system is commonly used for producing foreign proteins in Escherichia coli, but its reliance on the costly and metabolically demanding inducer IPTG limits its industrial use. This study engineered a low-temperature inducible system (LTIS) in E. coli Nissle 1917 (EcN) by combining the T7 expression system with the thermal inducible mechanism CI857-λPRPL to generate the new LTIS strain, ENL7P. The strain ENL7P-sfGFP-Km underwent overnight culture at 37 °C for 14-16 h, followed by subculturing at 30 °C for 24 h. This resulted in a notable 5.53-fold increase in the sfGFP induction rate when the strain was cultivated under 37-30 °C conditions. Moreover, gene expression was induced using a two-stage strategy. Initially, the strain was cultured overnight at 39 °C for 14-16 h, followed by a subculture at 30 °C for 6 h, and finally, another subculture at 30 °C for 24 h. This cultivation strategy led to an impressive 158.37-fold induction rate for sfGFP. Similar effects could be achieved through utilization of the LTIS system for inducing the production of thermophilic trehalose synthase from Thermus antranikianii (TaTS). The results of this study proved that the LTIS system has the potential for industrial applications.

A new scoring system for predicting the outcome of hepatocellular carcinoma patients without microvascular invasion-a large-scale multicentre study.

BACKGROUND: The prognosis of HCC patients without MVI (so called M0) is highly heterogeneous and the need for adjuvant therapy is still controversial. METHODS: Patients with HCC with M0 who underwent liver resection (LR) or liver transplantation (LT) as an initial therapy were included. The Eastern Hepatobiliary Surgery Hospital (EHBH)-M0 score was developed from a retrospective cohort to form the training cohort. The classification which was developed using multivariate cox regression analysis was externally validated. RESULTS: The score was developed using the following factors: α-fetoprotein level, tumour diameter, liver cirrhosis, total bilirubin, albumin and aspartate aminotransferase. The score differentiated two groups of M0 patients (≤3, >3 points) with distinct long-term prognoses outcomes (median overall survival (OS), 98.0 vs. 46.0 months; p < 0.001). The predictive accuracy of the score was greater than the other commonly used staging systems for HCC. And for M0 patients with a higher score underwent LR. Adjuvant transcatheter arterial chemoembolization (TACE) was effective to prolong OS. CONCLUSIONS: The EHBH M0 scoring system was more accurate in predicting the prognosis of HCC patients with M0 after LR or LT. Adjuvant therapy is recommended for HCC patients who have a higher score.

Salvage Surgery for Initially Unresectable HCC With PVTT Converted by Locoregional Treatment Plus Tyrosine Kinase Inhibitor and Anti-PD-1 Antibody.

BACKGROUND: This study aimed to compare the survival outcomes of patients with initially unresectable hepatocellular carcinoma (HCC) and portal vein tumor thrombus (PVTT) who underwent or did not undergo salvage surgery followed by a triple combination conversion treatment consisted of locoregional treatment (LRT), tyrosine kinase inhibitors (TKIs), and anti-PD-1 antibodies. METHODS: The data from 93 consecutive patients with initially unresectable HCC and PVTT across 4 medical centers were retrospectively reviewed. They were converted successfully by the triple combination treatment and underwent or did not undergo salvage resection. The baseline characteristics, conversion schemes, conversion treatment-related adverse events (CTRAEs), overall survival (OS), and progression-free survival (PFS) of the salvage surgery and non-surgery groups were compared. Multivariate Cox regression analysis was performed to identify independent risk factors for OS and PFS. Additionally, subgroup survival analysis was conducted by stratification of degree of tumor response and type of PVTT. RESULTS: Of the 93 patients, 44 underwent salvage surgery, and 49 did not undergo salvage surgery. The OS and PFS of the salvage surgery and non-surgery groups were not significantly different (P = .370 and .334, respectively). The incidence and severity of CTRAEs of the 2 groups were also comparable. Subgroup analyses revealed that for patients with complete response (CR) or types III-IV PVTT, there was a trend toward better survival in patients who did not undergo salvage surgery. Multivariate analysis showed that baseline α-fetoprotein and best tumor response per mRECIST criteria were independent prognostic factors for OS and PFS. CONCLUSIONS: For patients with initially unresectable HCC and PVTT who were successfully converted by the triple combination therapy, salvage liver resection may not be necessary, especially for the patients with CR or types III-IV PVTT.

Covalent organic framework reinforced hollow fiber bar for extraction and detection of bisphenols from beverages.

Bisphenols (BPs) can migrate from packaging materials into foods, resulting in potentially harmful residues. For example, accumulation of BPs is associated with endocrine disorders. Owing to matrix effects, development of an effective and eco-friendly sample pretreatment would be helpful for BPs detection in beverages packed in plastic containers. In this work, an extraction bar, composed of hollow fiber (HF) functionalized with covalent organic frameworks (COF@Tp-NDA) and 1-ocanol, was prepared for extraction of five BPs simultaneously. The synergistic effect of COF@Tp-NDA and 1-octanol improved the extraction efficiency of BPs from milk-based beverage, juice, and tea beverage. Under optimal conditions, limits of detection ranged from 0.10 to 2.00 ng mL-1 (R2 ≥ 0.9974) and recoveries ranged from 70.1 % to 106.8 %. This method has the potential to enrich BPs, supporting their accurate determination in complex beverages.

Palladium-Catalyzed Annulative π-Extension of Bay-Iodinated Triphenylenes to Access Polycyclic Aromatic Compounds.

A palladium-catalyzed annulative π-extension reaction of bay-iodinated triphenylenes with aryl iodides/o-chloroaromatic carboxylic acids was developed. This approach enabled the synthesis of diverse polycyclic aromatic compounds, including dibenzo[fg,op]tetracenes, azadibenzo[fg,op]tetracenes, and tribenzo[a,g,m]coronenes. Initial studies indicate that the resulting product, 2,3,8,9,14,15-hexakis(decyloxy)tribenzo[a,g,m]coronene, exhibits good liquid-crystalline properties.