A daily diary study of discrimination and distress in Mexican-origin adolescents: Testing mediating mechanisms.

The present 21-day daily diary study (conducted 2021-2022) tested anger and racism-related vigilance as potential transdiagnostic mediators linking exposure to racial and ethnic discrimination (RED) to distress (negative affect and stress, respectively). The data analytic sample included N = 317 Mexican-origin adolescents (Mage = 13.5 years; 50.8% male, 46.7% female; 2.5% non-binary) from the Midwestern United States. Results from longitudinal mediation models revealed significant mediation effects through anger and racism-related vigilance, respectively, in the association between daily RED and daily distress, both within and across adolescents. Implications for theory, research, and practice are discussed so that future work can leverage these novel findings toward promoting the well-being of Mexican-origin adolescents, especially those who live in contexts of ethnoracial adversity.

Investigating weight constraint methods for causal-formative indicator modeling.

Causal-formative indicators are often used in social science research. To achieve identification in causal-formative indicator modeling, constraints need to be applied. A conventional method is to constrain the weight of a formative indicator to be 1. The selection of which indicator to have the fixed weight, however, may influence statistical inferences of the structural path coefficients from the causal-formative construct to outcomes. Another conventional method is to use equal weights (e.g., 1) and assumes that all indicators equally contribute to the latent construct, which can be a strong assumption. To address the limitations of the conventional methods, we proposed an alternative constraint method, in which the sum of the weights is constrained to be a constant. We analytically studied the relations and interpretations of structural path coefficients from the constraint methods, and the results showed that the proposed method yields better interpretations of path coefficients. Simulation studies were conducted to compare the performance of the weight constraint methods in causal-formative indicator modeling with one or two outcomes. Results showed that higher biases in the path coefficient estimates were observed from the conventional methods compared to the proposed method. The proposed method had ignorable bias and satisfactory coverage rates in the studied conditions. This study emphasizes the importance of using an appropriate weight constraint method in causal-formative indicator modeling.

Non-contrast assessment of blood-brain barrier permeability to water in mice: An arterial spin labeling study at cerebral veins.

Blood-brain barrier (BBB) plays a critical role in protecting the brain from toxins and pathogens. However, in vivo tools to assess BBB permeability are scarce and often require the use of exogenous contrast agents. In this study, we aimed to develop a non-contrast arterial-spin-labeling (ASL) based MRI technique to estimate BBB permeability to water in mice. By determining the relative fraction of labeled water spins that were exchanged into the brain tissue as opposed to those that remained in the cerebral veins, we estimated indices of global BBB permeability to water including water extraction fraction (E) and permeability surface-area product (PS). First, using multiple post-labeling delay ASL experiments, we estimated the bolus arrival time (BAT) of the labeled spins to reach the great vein of Galen (VG) to be 691.2 ± 14.5 ms (N = 5). Next, we investigated the dependence of the VG ASL signal on labeling duration and identified an optimal imaging protocol with a labeling duration of 1200 ms and a PLD of 100 ms. Quantitative E and PS values in wild-type mice were found to be 59.9 ± 3.2% and 260.9 ± 18.9 ml/100 g/min, respectively. In contrast, mice with Huntington's disease (HD) revealed a significantly higher E (69.7 ± 2.4%, P = 0.026) and PS (318.1 ± 17.1 ml/100 g/min, P = 0.040), suggesting BBB breakdown in this mouse model. Reproducibility studies revealed a coefficient-of-variation (CoV) of 4.9 ± 1.7% and 6.1 ± 1.2% for E and PS, respectively. The proposed method may open new avenues for preclinical research on pathophysiological mechanisms of brain diseases and therapeutic trials in animal models.

[Effect of Suanzaoren Decoction on expression of ionotropic glutamate receptors and synaptic plasticity in hippocampus of anxiety rats].

This study investigated the effect of Suanzaoren Decoction on the expression of N-methyl-D-aspartate receptors(NMDAR) and α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptors(AMPAR) in the hippocampus and synaptic plasticity in rats with conditioned fear-induced anxiety. The effect of Suanzaoren Decoction on rat behaviors were evaluated through open field experiment, elevated plus maze experiment, and light/dark box experiment. Enzyme-linked immunosorbent assay(ELISA) was used to measure the levels of glutamate(Glu) and γ-aminobutyric acid(GABA) in the rat hippocampus. Real-time fluorescence quantitative PCR(qRT-PCR) and Western blot were employed to assess the gene and protein expression of ionotropic glutamate receptors in the hippocampal region. Transmission electron microscopy was utilized to observe the changes in the ultrastructure of synaptic neurons in the hippocampal region. Long-term potentiation(LTP) detection technique was employed to record the changes in population spike(PS) amplitude in the hippocampal region of mice in each group. The behavioral results showed that compared with the model group, the Suanzaoren Decoction group effectively increased the number of entries into open arms, time spent in open arms, percentage of time spent in open arms out of total movement time, number of entries into open arms out of total entries into both arms(P<0.01), and significantly increased the time spent in the light box and the number of shuttle crossings(P<0.01). There was an increasing trend in the number of grid crossings, entries into the center grid, and time spent in the center grid, indicating a significant anxiolytic effect. ELISA results showed that compared with the model group, the Suanzaoren Decoction group exhibited significantly reduced levels of Glu, Glu/GABA ratio(P<0.01), and significantly increased levels of GABA(P<0.01) in the rat hippocampus. Furthermore, Suanzaoren Decoction significantly decreased the gene and protein expression of NMDAR(GluN2B and GluN2A) and AMPAR(GluA1 and GluA2) compared with the model group. Transmission electron microscopy results demonstrated improvements in synapses, neuronal cells, and organelles in the hippocampal region of the Suanzaoren Decoction group compared with the model group. LTP detection results showed a significant increase in the PS amplitude changes in the hippocampal region of Suanzaoren Decoction group from 5 to 35 min compared with the model group(P<0.05, P<0.01). In conclusion, Suanzaoren Decoction exhibits significant anxiolytic effects, which may be attributed to the reduction in NMDAR and AMPAR expression levels and the improvement of synaptic plasticity.

Orrella daihaiensis sp. nov., a bacterium isolated from Daihai Lake in Inner Mongolia.

A novel aerobic, Gram-staining-negative, non-motile, short-rod-shaped strain, designated f23T, was obtained from Daihai Lake, Inner Mongolia, Republic of China. 16S rRNA gene sequences analysis showed that f23T belongs to the genus Orrella and is most closely related to Orrella marina H-Z20T with 98.35% sequence similarity. The strain was oxidase positive, catalase positive and had well growth at pH 6.5-8.5, at temperature 28-40 °C and at 0-4.5% (w/v) NaCl. Colonies incubated at 37 °C on marine 2216 agar for 3 days were white, smooth, transparent, circular and less than 1.0 mm in diameter. The total genome size of f23T was 2,803,849 bp with a G + C content of 52.79%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain f23T and O. marina H-Z20T were 69.62% and 20.5%, which both below the species delineation threshold. Chemotaxonomic analysis showed that C16:0, cyclo-C17:0, C18:0, Sum Feature 3 (C16:1ω7c and/or C16:1ω6c) and Sum Feature 8 (C18:1ω6c and C18:1ω7c) as the major fatty acids, ubiquinone-8 as the major isoprenoid quinone, phosphatidylethanolamine as the major cellular polar lipids. Based on the polyphasic analysis, f23T represents a novel species within the genus Orrella, for which the name Orrella daihaiensis sp. nov. is proposed. The type strain is f23T (= CGMCC 1.18761 T = KCTC 82425 T).

Low-cost and efficient confocal imaging method for arabidopsis flower.

For an extensive period of time apical meristem (SAM) has been considered as a mysterious organ, due to its small, hidden and dynamic structure. Confocal imaging, combined with fluorescent reporters, enables researchers to unveil the mechanisms underlying cellular activities, such as gene expression, cell division, growth patterns and cell-cell communications. Recently, a series of protocols were developed for confocal imaging of inflorescence meristem (IM) and floral meristem (FM). However, the requirement of high configuration, such as the need of a water-dipping lens without coverslip and the specialized turrets associated with fixed-stage microscopes, impedes the wide adoption of these methods. We exploited an improved object slide and matching method aiming to decrease the configuration requirement. Following this protocol, various dry microscope lenses can be selected with flexibility for building 3D images of IM and FM.

The relationships among parental psychological control/autonomy support, self-trouble, and internalizing problems across adolescent genders.

This study aimed to explore the relationships among early adolescents' perceived parental psychological control/autonomy support, self-trouble, and internalizing problems as well as the potential gender differences in these relationships. Multiple-group path analysis was performed on the data collected from 1,089 adolescents in Beijing junior high schools. Results revealed that parental psychological control (autonomy support) was associated with adolescents' more (fewer) internalizing problems, and self-trouble acted as a mediator in these two relationships. Moreover, only the indirect relationship between parental autonomy support and internalizing problems via self-trouble was moderated by gender, with girls showing a little stronger indirect effect than boys, and specifically, it was the relationship between autonomy support and self-trouble that existed gender differences, with girls showing higher coefficient than boys. The relationship between parental psychological control/autonomy support and early adolescents' internalizing problems was discussed with regard to self-trouble and gender differences.

[Development of Portable Anesthesia Video Laryngoscope Based on ARM].

In the process of tracheal intubation, the anesthesia video laryngoscope is used to lift up the patient's epiglottis to expose the glottis, and thus guiding the medical staff to perform anesthesia intubation accurately. This paper describes the method and significance of video laryngoscope in the process of guiding anesthesia intubation, introduces the overall structure and function of portable anesthesia video laryngoscope, the design is mainly focused on image acquisition module, core board circuit, video decoding circuit, lithium battery charging circuit and external storage circuit, at last briefly introduces work process of the video laryngoscope.

Comparison on emulsifying and emulgelling properties of low methoxyl pectin with varied degree of methoxylation from different de-esterification methods.

Low methoxyl pectin (LMP) with different degree of methoxylation (DM, 40-50 %, 20-30 % and 5-10 %) were prepared from commercially available citrus pectin using high hydrostatic pressure assisted enzymatic (HHP-pectin) and traditional alkaline (A-pectin) de-esterification method. The results showed that both de-esterification methods and DM exhibited LMPs with varied physicochemical, structural, and functional properties. As the DM decreased, LMP showed a decrease in molecular weight (Mw), while an increase in negative charges and rhamnogalacturonan I (RG-I) ratio, accompanied with better emulsion stability, emulsion gel strength and water-holding properties. Relative to A-pectin, HHP-pectin had higher Mw and lower RG-I side chain ratio, contributing to its better thermal stability, apparent viscosity, and emulgelling properties. HHP-pectin with lower DM (5-10 %) showed superior thickening, emulsifying and emulgelling properties, while that with higher DM (40-45 %) had superior thermal stability, which provided alternative for de-esterification and targeted structural modification of pectin.

Senolytic therapy preserves blood-brain barrier integrity and promotes microglia homeostasis in a tauopathy model.

Cellular senescence, characterized by expressing the cell cycle inhibitory protein p21/CDKN1A, is evident in driving age-related diseases. Senescent cells play a crucial role in the initiation and progression of tau-mediated pathology, suggesting that targeting cell senescence offers a therapeutic potential for treating tauopathy associated diseases. This study focuses on identifying non-invasive biomarkers and validating their responses to a well-characterized senolytic therapy combining dasatinib and quercetin (D+Q), in a widely used tauopathy mouse model, PS19. We employed human-translatable MRI measures, including water extraction with phase-contrast arterial spin tagging (WEPCAST) MRI, T2 relaxation under spin tagging (TRUST), and structural MRI, and longitudinally assessed brain physiology and regional volumes in PS19 mice. Our data reveal increased BBB permeability, decreased oxygen extraction fraction, and brain atrophy in 9-month-old PS19 mice compared to their littermate controls. (D+Q) treatment effectively preserves BBB integrity, rescues cerebral oxygen hypometabolism, attenuates brain atrophy, and alleviates tau hyperphosphorylation in PS19 mice. Mechanistically, D+Q treatment induces a shift of microglia from a disease-associated to a homeostatic state, reducing a senescence-like microglial phenotype marked by increased p21/CDKN1A. D+Q-treated PS19 mice exhibit enhanced cue-associated cognitive performance in the tracing fear conditioning test compared to the vehicle-treated littermates, implying improved cognitive function by D+Q treatment. Our results pave the way for application of senolytic treatment as well as these noninvasive MRI biomarkers in clinical trials in tauopathy associated neurological disorders.

Clinical phenotypic characteristics in patients carrying MYH7-R143Q mutation with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) represents one of the most common inherited cardiac conditions, and more than 50 % have a tendency of familial aggregation. However, there is a lack of plenty pedigrees to analyze the clinical characteristics. This study collected 1023 unrelated HCM probands, conducted Sanger sequencing on whom carrying MYH7-R143Q and analyzed the clinical data. The detection rate of MYH7-R143Q was 2.54 % (26/1023). In patients with HCM carrying MYH7-R143Q, the diagnosis age is often concentrated in 31-40 years with moderate hypertrophy and fibrosis, which usually concentrate in the anterior and inferior septum of the basal and mid regions, representing moderate risk of SCD. Besides, this variant represented different genetic characteristics, including incomplete penetrance of autosomal dominant inheritance, polygenic cumulative effect and et al. It is the first time to investigate clinical phenotypes in multiple families carrying the same variant locus MYH7-R143Q, providing a theoretical basis for genetic counseling in clinical practice.

A widely conserved protein Rof inhibits transcription termination factor Rho and promotes Salmonella virulence program.

Transcription is crucial for the expression of genetic information and its efficient and accurate termination is required for all living organisms. Rho-dependent termination could rapidly terminate unwanted premature RNAs and play important roles in bacterial adaptation to changing environments. Although Rho has been discovered for about five decades, the regulation mechanisms of Rho-dependent termination are still not fully elucidated. Here we report that Rof is a conserved antiterminator and determine the cryogenic electron microscopy structure of Rho-Rof antitermination complex. Rof binds to the open-ring Rho hexamer and inhibits the initiation of Rho-dependent termination. Rof's N-terminal α-helix undergoes conformational changes upon binding with Rho, and is key in facilitating Rof-Rho interactions. Rof binds to Rho's primary binding site (PBS) and excludes Rho from binding with PBS ligand RNA at the initiation step. Further in vivo analyses in Salmonella Typhimurium show that Rof is required for virulence gene expression and host cell invasion, unveiling a physiological function of Rof and transcription termination in bacterial pathogenesis.

Research on user's highly sensitive privacy disclosure intention in home intelligent health service system: A perspective from trust enhancement mechanism.

Objective: The aim is to investigate the determinants and mechanisms that influence user's highly sensitive privacy disclosure intention (HSPDI) in home intelligent health service system (HIHSS). Methods: This study improves the privacy calculus theory by considering the influence of service providers' trust enhancement mechanism besides benefit and risk factors and investigates their impact on users' HSPDIs. This study takes perceived valence and perceived security as the trade-off result among perceived benefits, perceived risks, financial trust enhancement mechanism, and the technical trust enhancement mechanism and suggests that perceived valence and perceived security further affect users' HSPDI in HIHSS. Moreover, the common and differential effects of the perceived justice of privacy violation compensation (PJOPVC) and the perceived effectiveness of privacy protection technologies (PEOPPTs) are studied. The structural equation model is used to analyze 204 valid samples to test the proposed model. Results: The results show that perceived benefits and perceived risks are important predictors of perceived valence and perceived security, and further affect users' HSPDI. We find PJOPVC has a greater impact on perceived valence while PEOPPT has a greater impact on perceived security. Conclusions: We recommend that the HSPDI of users with low perceived valence can be improved by providing privacy violation compensation while the HSPDI of users with low perceived security can be enhanced by popularizing relevant knowledge of privacy protection technologies.

Potential role of cell wall pectin polysaccharides, water state, and cellular structure on twice "increase-decrease" texture changes during kohlrabi pickling process.

Pickled kohlrabi is a traditional and favored vegetable product in China. During pickling, the hardness, springiness, and chewiness of kohlrabi all experienced a typical change with twice "increase-decrease" trend. However, little is known about its mechanism. In this study, in situ analysis including immunofluorescence, low field nuclear magnetic, and transmission electron microscopy were used to explore the effects of cell wall pectin, water state, and cellular structure on kohlrabi texture changes during pickling. Results revealed that at the early stage, due to the rapid loss of water after three times salting, the cells shrank and the interstitial space reduced, resulting in the first increase on kohlrabi texture. Subsequently, the dehydration-rehydration caused by the first brine processing resulted in the first decrease on kohlrabi texture. Then under the action of PME enzyme, more low-esterified pectin was produced, and chelate-soluble pectin with more branched structure was further formed, leading to another elevation of the sample texture. As the pickling continued, under the combined action of PG and PME, the molecular weight of pectin was decreased and the rigidity of the cell tissue was destroyed, caused kohlrabi texture continued to decline. These researches could provide important information and guidance for better maintaining the texture of pickled vegetables during processing.

Breast cancer is associated with coronary heart disease: a cross-sectional survey of NHANES 1999-2018.

Background: Understanding the correlation between female breast cancer (BC) and the prevalence of coronary heart disease (CHD) is important for developing prevention strategies and reducing the burden of female social disease. This study aimed to evaluate the relationship between BC and CHD using data from the National Health and Nutrition Examination Survey (NHANES) database from 1999 to 2018. Methods: The study cohort included 16,149 eligible non-pregnant female participants aged 20 years or older. Logistic regression was used to analyze the relationship between BC and CHD, excluding the interaction between covariates and BC through hierarchical subgroup analysis. Results: The study found that participants with BC had a 2.30 times greater risk of developing CHD compared to those without BC [95% confidence interval (CI): 2.29-2.31]. After adjusting for all included covariates, BC was still significantly associated with CHD risk (odds ratio: 1.11, 95% CI: 1.10-1.12). When participants were stratified by age, education level, and prevalence of hypertension, it was evident that participants with BC had a higher risk of developing CHD compared to those without BC, although the effect of BC on CHD varied across stratification. Conclusions: Our study demonstrates the close relationship between CHD and female BC. Therefore, it is necessary to screen patients with CHD for BC and monitor BC survivors for the long-term risk of developing CHD.

Excipient emulsion prepared with pectin and sodium caseinate to improve the bioaccessibility of carotenoids in mandarin juice: The effect of emulsifier and polymer concentration.

Excipient emulsions were prepared using different emulsifiers (pectin and sodium caseinate, individually or compositely) to study the emulsifying properties and their co-digested effects on the retention and bioaccessibility of carotenoids in mandarin juice, which is a good source of carotenoids in people's diet. Results showed that both pectin (PC) and pectin-sodium caseinate (PC-SC) emulsion significantly increased the carotenoids retention and bioaccessibility of mandarin juice, with the effects depending on both emulsifiers and polymer concentration. Whether for PC or PC-SC emulsion, lower pectin content accompanied with lower viscosity showed higher carotenoids bioaccessibility. And for the complexed emulsions, appropriate sodium caseinate addition could be more beneficial in improving carotenoids bioaccessibility. It had been found that the viscosity comparing with particle size seemed to play a more important role in affecting carotenoid bioaccessibility during the co-digestion. This study could provide a basis for improving the carotenoids bioaccessibility in the real system of fruits and vegetables with excipient emulsions.

Magnetic bead-based salivary peptidome profiling for periodontal-orthodontic treatment.

BACKGROUND: Patients with periodontitis seek periodontal-orthodontic treatment to address certain functional and aesthetic problems. However, little is known of the effect of periodontitis on orthodontic treatment. Thus, we compared the differences in peptide mass fingerprints of orthodontic patients with and without periodontitis by MALDI-TOF MS using a magnetic bead-based peptidome analysis of saliva samples. In this way, we aimed to identify and explore a panel of differentially-expressed specific peptides. RESULTS: Saliva samples from 24 patients (eight orthodontic patients without periodontitis, eight with periodontitis and another eight with periodontitis but no orthodontic treatment) were analyzed, and peptide mass fingerprints were created by scanning MS signals using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) combined with magnetic beads. Nine mass peaks showed significant differences. Orthodontic patients in the group without periodontal disease showed higher mass peaks for seven peptides of the nine, whereas the mass peaks for the other two peptides were higher in the periodontal-orthodontic patients. Besides, these differentially-expressed peptides were sequenced. CONCLUSIONS: The elucidated candidate biomarkers indicated interactions between periodontal condition and orthodontic treatment and their contributions to the changes of saliva protein profiles. Our results provide novel insight into the altered salivary protein profile during periodontal-orthodontic treatment, and may lead to the development of a therapeutic monitoring strategy for periodontics and orthodontics.

Curcumin loading and colon release of pectin gel beads: Effect of different de-esterification method.

Low methoxyl citrus pectin (LMP) de-esterified from high hydrostatic pressure assisted enzymatic (HHP-pectin) and two other traditional methods was characterized, and curcumin-pectin calcium gel beads were prepared to study curcumin-loading and colon-targeted delivery abilities. It was found there was no significant difference among different LMP on amorphous structure, while significantly higher Rha/GalA ratio of HHP-pectin indicated higher rhamnogalacturonan Ⅰ (RG-I) proportion and branching extent. Curcumin was well embedded in LMP beads with improved stability. HHP-pectin beads showed significantly higher hardness, chewiness and encapsulation efficiency, while lower swelling ratio. Moreover, in vitro simulated digestion showed gel beads can deliver curcumin to colon and inhibit premature release. HHP-pectin beads could release curcumin more quickly in colon, probably because of differences on texture properties, which may be depended on molecular structure. Thus, LMP especially HHP-pectin calcium gel as colon-targeted delivery system for curcumin may have potential application in function food and drug delivery.

Cytogenetic identification and molecular marker development of a novel wheat-Leymus mollis 4Ns(4D) alien disomic substitution line with resistance to stripe rust and Fusarium head blight.

Leymus mollis (Trin.) Pilg. (2n = 4x = 28, NsNsXmXm) potentially harbours useful genes that might contribute to the improvement of wheat. We describe M862 as a novel wheat-L. mollis alien disomic substitution line from a cross between wheat cv. 7182 and octoploid Tritileymus M47. Cytological observations indicate that M862 has a chromosome constitution of 2n = 42 = 21II. Two 4D chromosomes of wheat substituted by two L. mollis Ns chromosomes were observed, using the GISH and ND-FISH analyses. Molecular marker, 55K SNP array and wheat-P. huashanica liquid array (GenoBaits®WheatplusPh) analyses further indicate that the alien chromosomes are L. mollis 4Ns. Therefore, it was deduced that M862 was a wheat-L. mollis 4Ns(4D) alien disomic substitution line. There were also changes in chromosomes 1A, 1D, 2B and 5A detected by ND-FISH analysis. Transcriptome sequencing showed that the structural variation of 1D, 1A and 5A may have smaller impact on gene expression than that for 2B. In addition, a total of 16 markers derived from Lm#4Ns were developed from transcriptome sequences, and these proved to be highly effective for tracking the introduced chromosome. M862 showed reduced height, larger grains (weight and width), and was highly resistance to CYR32 and CYR34 stripe rust races at the seedling stage and mixed stripe rust races (CYR32, CYR33 and CYR34) at the adult stage. It was also resistance to Fusarium head blight (FHB). This alien disomic substitution line M862 may be exploited as an important genetic material in the domestication of stipe rust and FHB resistance wheat varieties.

Correlation between US-FNAC with BRAF V600E Mutation Analysis and Central Neck Lymph Node Metastasis in cN0 Papillary Thyroid Cancer.

The aim of this study was to explore the correlation between ultrasound-guided fine-needle aspiration cytology(US-FNAC) combined with BRAF V600E mutation analysis and central neck lymph node metastasis in cN0 papillary thyroid cancer, so as to provide reliable molecular evidence to use it for preoperative evaluation, operation procedure design, and postoperative follow-up planning in clinic. Specimens were obtained from 250 patients with cN0 thyroid cancer (TI-RADS≥4a, highly suspected of PTC by US-FNAC) after bilateral thyroidectomy and central neck lymph node dissection with accessible postoperative pathologic results of PTC and central neck lymph nodes and used for cytological diagnosis by H&E stain and BRAF V600E mutation detection. Single-factor analysis showed that differences between the central neck lymph node metastasis and nonmetastasis groups were statistically significant in gender, BRAF V600E mutation, and extracapsular extension. Logistic multivariate regression analysis showed significant differences in gender, BRAF V600E mutation, and extracapsular extension. Positive BRAF V600E mutations by US-FNAC, extracapsular extension, and male gender are risk factors of central neck lymph node metastasis in cN0 PTC metastatic PTC to central neck lymph node. Patients with those factors should undergo prophylactic central neck lymph node dissection.