Distinct Phenotypes Induced by Different Degrees of Transverse Aortic Constriction in C57BL/6N Mice

The transverse aortic constriction (TAC) model surgery is a widely used disease model to study pressure overload–induced cardiac hypertrophy and heart failure in mice. The severity of adverse cardiac remodeling of the TAC model is largely dependent on the degree of constriction around the aorta, and the phenotypes of TAC are also different in different mouse strains. Few studies focus on directly comparing phenotypes of the TAC model with different degrees of constriction around the aorta, and no study compares the difference in C57BL/6N mice. In the present study, C57BL/6N mice aged 10 weeks were subjected to sham, 25G TAC, 26G TAC, and 27G TAC surgery for 4 weeks. We then analyzed the different phenotypes induced by 25G TAC, 26G TAC, and 27G TAC in c57BL/6N mice in terms of pressure gradient, cardiac hypertrophy, cardiac function, heart failure situation, survival condition, and cardiac fibrosis. All C57BL/6N mice subjected to TAC surgery developed significantly hypertrophy. Mice subjected to 27G TAC had severe cardiac dysfunction, severe cardiac fibrosis, and exhibited characteristics of heart failure at 4 weeks post-TAC. Compared with 27G TAC mice, 26G TAC mice showed a much milder response in cardiac dysfunction and cardiac fibrosis compared to 27G TAC, and a very small fraction of the 26G TAC group exhibited characteristics of heart failure. There was no obvious cardiac dysfunction, cardiac fibrosis, and characteristics of heart failure observed in 25G TAC mice. Based on our results, we conclude that the 25G TAC, 26G TAC, and 27G TAC induced distinct phenotypes in C57BL/6N mice.

Narrative therapy to relieve stigma in oral cancer patients: A randomized controlled trial

AIMS AND OBJECTIVES

This study aimed to evaluate the efficacy of narrative therapy in relieving stigma in oral cancer patients who underwent major surgical treatment.

BACKGROUND

Health-related stigma compromises mental health and life quality in people with physical or mental abnormalities. Narrative therapy has been implemented to overcome stigma among populations in a diversity of disease states. However, the effectiveness of narrative therapy in relieving stigma among patients with oral cancer is not known.

DESIGN

This study was a randomized controlled trial, in which 100 oral cancer patients were selected and randomly assigned to the 'narrative therapy' group, who received narrative therapy treatment in addition to standard care, and the 'control' group, who was provided standard care only.

METHODS

This research combined measurement of several questionnaires to evaluate stigma. Analysis of variance and paired t tests were employed for data analysis.

RESULTS

Findings in this study demonstrated that narrative therapy treatment effectively relieved oral cancer patients' sense of shame, reducing overall stigma and significantly improving self-esteem and social relationships.

CONCLUSIONS

Narrative therapy was demonstrated to be a promising therapeutic intervention for stigma relief in oral cancer patients.

SUMMARY STATEMENT

What is already known about this topic? Stigma is common among oral cancer patients, especially those who undergo major surgical resection. Psychological intervention is highly recommended in addition to postsurgical care. Narrative therapy might help relieve stigma among oral cancer patients. What this paper adds? Conventional postsurgical care did not improve oral cancer patients' psychological situation. A 7-week intervention of narrative therapy treatment significantly reduced stigma and enhanced sense of self-worth and social support among oral cancer patients. The implications of this paper: Narrative therapy can be clinically accepted as a therapeutic approach to assist oral cancer patients with stigma after major surgery. Tailored approaches, including patient-customized methods, should be encouraged in conducting narrative therapy.

[Risk factors of postoperative complication after total gastrectomy in advanced gastric cancer patients receiving neoadjuvant chemotherapy]

Objective: At present, there are few studies focusing on the factors short-term complications after total gastrectomy in patients with advanced gastric cancer receiving neoadjuvant chemotherapy (NACT). The purpose of this study is to provide a reference for clinical prevention of complications in these patients. Methods: A retrospective case-control study was conducted. Case inclusion criteria: (1) clinical stage II-III gastric cancer diagnosed by preoperative gastroscopy, pathology, abdominal CT, EUS or PET-CT; (2) evaluated suitable for NACT by MDT discussion; (3) no previous history of other malignant tumors and no concurrent tumor; (4) undergoing total gastrectomy+ D2 lymphadenectomy after NACT. Exclusion criteria: (1) age <18 or >80 years old; (2) severe concurrent diseases, and ASA classification>grade III; (3) stump gastric cancer or history of gastric surgery; (4) incomplete clinicopathological data. According to the above criteria, clinicopathological data of 140 advanced gastric cancer patients who underwent total gastrectomy after NACT in Chinese PLA General Hospital between June 2012 and June 2019 were collected, including 109 males and 31 females with mean age of (56.9±11.4) years and body mass indey (BMI) of (23.3±3.1) kg/m(2). Logistic analysis was used to analyze the relationship between postoperative complication and clinicopathological data. Factors in univariate analysis with P<0.05 were included in the multivariate analysis. Results: Postoperative complications (Clavien-Dindo classification ≥ II) occurred in 35 cases (25.0%) and severe complications (Clavien-Dindo classification ≥ IIIa) occurred in 4 cases (2.9%), including 1 case of esophago-jejunal anastomotic leakage, 1 case of vena cava thrombosis, 1 case of pleural effusion, 1 case of septic shock during perioperative days resulting in death. Univariate analysis showed that BMI (P=0.011), cycle of NACT (P=0.027), tumor diameter (P=0.021), and vascular invasion (P=0.033) were associated with postoperative complication within 30 days, while open/laparoscopic total gastrectomy were not associated with postoperative complication (P=0.926). Multivariate analysis revealed that BMI ≥ 25 kg/m(2) (OR=3.294, 95% CI: 1.343-8.079, P=0.009) and < 4 cycles of NACT (OR=2.922, 95% CI: 1.217-7.016, P=0.016) were independent risk factors for postoperative complication. The 3-year overall survival rates of patients with or without complication were 54.4% and 64.0%, respectively (P=0.395), and 3-year disease-free survival rates were 47.4% and 52.9%, respectively (P=0.587). Conclusions: Higher BMI and fewer cycles of NACT are independent risk factors of postoperative complication in advanced gastric cancer patients undergoing total gastrectomy after NACT. No obvious association is found between postoperative complication and surgical approaches.

Tafolecimab, a novel potential long-acting PCSK9 monoclonal antibody: efficacy and safety in healthy and hypercholesterolemia subjects

Background

LDL cholesterol (LDL-C) is a well-established risk factor for cardiovascular disease. PCSK9 binds LDL receptors, targeting them for degradation. The dosing intervals for currently available PCSK9 monoclonal antibodies are once every 2 or 4 weeks. Tafolecimab, a novel recombinant human PCSK9 monoclonal antibody, was found to have higher affinity with PCSK9 and show longer LDL-C reduction compared to evolocumab in preclinical studies.

Purposes

The objectives for the SAD and MAD studies were to investigate the safety and efficacy of tafolecimab and explore the optimal dosing schedule.

Methods

The phase 1 study was a randomized, placebo-controlled, double-blind, single-ascending dose study (SAD) in Chinese healthy subjects, who were randomized 3:1 to tafolecimab and placebo (n=58). SAD subjects received tafolecimab subcutaneously at 25/75/150/300/450/600mg, or intravenously at 75/450mg, monitored up to day 84. The phase 2 study was a randomized, double-blind, placebo-controlled, repeated-dosing, multiple ascending dose (MAD) study in patients with hypercholesterolemia, who were randomized 4:1 to tafolecimab and placebo (n=60). MAD subjects received tafolecimab subcutaneously at 75/140mg every 2 weeks, 300/420mg every 4weeks, 450/600mg every 6 weeks up to day 84 or 98 with 3 months follow-up.

Results

In the SAD, the maximum mean reduction in LDL-C ranged from 52.2% to 72.1% and was achieved as early as 5 days (figure 1a). The duration of LDL-C reduction was tafolecimab dose dependent. In the MAD, the mean LDL-C concentrations were reduced by tafolecimab for each dose at 12 weeks relative to baseline (ranging from 54.30% to 72.26%; p&lt;0.001). Particularly, a 56.52% (−72.50%, −40.54%) reduction of LDL-C was observed in the cohort of 600mg Q6W. The effect sustained till week 14 (8 weeks after the last dose) where there was still a 43.46% (−60.96%, −25.96%) reduction from baseline (figure 1b). The mean reduction of Lp(a) at week 12 ranged from 24.04% to 50.59% relative to baseline. Tafolecimab reduced the other lipids when comparing with placebo. The pharmacokinetics/pharmadynamics (LDL-C) profiles of tafolecimab were well characterised and support the potential dosing interval of 6–8 weeks subcutaneously.

Both healthy and hypercholesterolemia subjects are generally tolerable to tafolecimab. Reported treatment-emergent adverse events (TEAEs) were: tafolecimab 23 (52.3%) vs. placebo 8 (57.1%); tafolecimab 34 (70.8%) vs. placebo 9 (75.0%) in the SAD and MAD respectively. There were no serious TEAEs or events leading to death or treatment discontinuation in both SAD and MAD.

Conclusions

Tafolecimab was well tolerated in both healthy and hypercholesterolemia in Chinese subjects, and improved lipid profile including LDL-C, Lp(a) and other lipids. The sustained effects on LDL-C suggests the potential of tafolecimab as a long-lasting PCSK9 inhibitor with dosing interval of 6–8 weeks or beyond.

Figure 1. LDL-C: Percent change from baseline

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Innovent Biologics (Suzhou), China

Plasma mtDNA copy numbers are associated with GSTK1 expression and inflammation in type 2 diabetes

AIMS

Mitochondrial dysfunction is involved in the pathogenesis of type 2 diabetes. Glutathione S-transferase kappa 1 (GSTK1) is critical to maintain mitochondrial function and homeostasis. We aimed to investigate whether a potential link exists between mitochondrial DNA (mtDNA) copy numbers and inflammation, non-esterified fatty acids (NEFA) and GSTK1 expression in type 2 diabetes.

METHODS

We assessed mtDNA copy numbers in plasma and GSTK1 expression in white blood cells in 123 people with type 2 diabetes and in 121 healthy controls using a quantitative polymerase chain reaction (qPCR). An automatic chemistry or immunoassay analyser was used to determine serum glucose, lipids and inflammatory markers. Multiple linear regression and multivariable logistic regression models were used to evaluate associations and risks.

RESULTS

Compared with healthy controls, individuals with diabetes showed higher mtDNA copy numbers (t = -3.938, P < 0.001) and lower GSTK1 expression (Z = -2.985, P = 0.002). mtDNA copy number was associated with type 2 diabetes risk [odds ratio (OR) = 1.80, 95% confidence intervals (CI) 1.25-2.58, P = 0.001] after controlling for confounding factors. In individuals with diabetes, mtDNA copy number was negatively associated with GSTK1 expression (β = -0.235, P = 0.036) and positively associated with serum high-sensitive C-reactive protein (hsCRP) (β = 0.839, P < 0.001), tumour necrosis factor alpha (TNF-α) (β = 0.549, P < 0.001), interleukin-6 (IL-6) (β = 0.589, P = 0.006) and NEFA (β = 0.001, P = 0.020). In the diabetic group, individuals with an abnormal increase in NEFA, hsCRP, TNF-α and IL-6 showed significantly elevated mtDNA copy numbers (all P < 0.05).

CONCLUSIONS

mtDNA copy numbers in plasma might have an important role in the progression of diabetic chronic inflammation via inhibition of GSTK1 and could be a potential biomarker for type 2 diabetes.

Meta-analysis of the effects of helmet-assisted non-invasive ventilation in the treatment of acute respiratory failure

OBJECTIVE

To study the efficacy of helmet-assisted non-invasive ventilation and conventional ventilation in the treatment of acute respiratory failure (ARF).

MATERIALS AND METHODS

Cochrane Library, PubMed, Embase and CNKI databases were searched for randomized controlled trials and case-control trials of helmet-assisted noninvasive ventilation in the treatment of ARF. The outcome measures included respiratory rate, intubation rate, complication rate, mortality rate and arterial blood gas analysis of the commonly used indicators (PaCO2/ PaO2 / pH). The results of the included studies' odds ratio (OR) and its 95% confidential interval (CI) were analyzed using Stata software.

RESULTS

The results of the analysis showed that the in-hospital mortality, intubation rate and complication rate were all significantly decreased with the p-value less than 0.05, which was statistically significant.

CONCLUSIONS

Helmet-assisted noninvasive ventilation can significantly reduce hospital mortality, intubation rate and complication rate, improving the survival rate and prognosis of patients with ARF.

Thermal and Quantum Melting Phase Diagrams for a Magnetic-Field-Induced Wigner Solid

A sufficiently large perpendicular magnetic field quenches the kinetic (Fermi) energy of an interacting two-dimensional (2D) system of fermions, making them susceptible to the formation of a Wigner solid (WS) phase in which the charged carriers organize themselves in a periodic array in order to minimize their Coulomb repulsion energy. In low-disorder 2D electron systems confined to modulation-doped GaAs heterostructures, signatures of a magnetic-field-induced WS appear at low temperatures and very small Landau level filling factors (ν≃1/5). In dilute GaAs 2D hole systems, on the other hand, thanks to the larger hole effective mass and the ensuing Landau level mixing, the WS forms at relatively higher fillings (ν≃1/3). Here we report our measurements of the fundamental temperature vs filling phase diagram for the 2D holes' WS-liquid thermal melting. Moreover, via changing the 2D hole density, we also probe their Landau level mixing vs filling WS-liquid quantum melting phase diagram. We find our data to be in good agreement with the results of very recent calculations, although intriguing subtleties remain.

Novel GLI3 Mutations in Chinese Patients with Non-syndromic Post-axial Polydactyly

BACKGROUND

Polydactyly, characterized by supernumerary digits in the upper or lower extremities, is the most common congenital digital abnormalities. It derives from the defective patterning of anteroposterior axis of the developing limb, with various etiology and clinical heterogeneity. The patients with post-axial polydactyly type A (PAPA) have the typical symptom of a well-formed supernumerary digit outside the fifth digit.

OBJECTIVE

The aim of present study was to identify the causative mutations of two unrelated Han Chinese patients with non-syndromic PAPA.

METHODS

Two unrelated Han Chinese patients and 100 ethnicity-matched, unrelated normal controls were recruited for this study. BGISEQ-500 exome sequencing was performed in the two patients, followed by validation in the patients and 100 controls by using Sanger sequencing.

RESULTS

Two mutations in the GLI family zinc finger 3 gene (GLI3), including a frameshift mutation c.3437_3453delTCGAGCAGCCCTGCCCC (p.L1146RfsX95) and a nonsense mutation c.3997C>T (p.Q1333X), were identified in two patients but were absent in the 100 healthy controls.

CONCLUSION

The two GLI3 mutations, p.L1146RfsX95 and p.Q1333X, may account for non-syndromic PAPA in the two patients, respectively. The findings of this study may expand the mutational spectrum of GLI3-PAPA and provide novel insights into the genetic basis of polydactyly.

Gender and age differences in the association between sleep characteristics and fasting glucose levels in Chinese adults

AIM

The present study examined the associations between night-time sleep duration, midday napping duration and bedtime, and fasting glucose levels, and whether or not such associations are dependent on gender and age.

METHODS

This study was a cross-sectional analysis of 172,901 adults aged≥40 years living in mainland China. Sleep duration was obtained by self-reports of bedtime at night, waking-up time the next morning and average napping duration at midday. Fasting plasma glucose (FPG)≥7.0mmol/L was defined as hyperglycaemia. Independent associations between night-time sleep duration, midday naptime duration and bedtime with hyperglycaemia were evaluated using regression models.

RESULTS

Compared with night-time sleep durations of 6-7.9h, both short (<6h) and long (≥8h) night-time sleep durations were significantly associated with an increased risk of hyperglycaemia in women [odds ratio (OR): 1.12, 95% confidence interval (CI): 1.01-1.29 and OR: 1.14, 95% CI: 1.08-1.21, respectively], and revealed a U-shaped distribution of risk in women and no significant association in men. Long midday nap durations (≥1h) were significantly but weakly associated with hyperglycaemia (OR: 1.04, 95% CI: 1.01-1.09) compared with no napping without interactions from gender or age, whereas the association between bedtime and fasting glucose levels did vary according to gender and age.

CONCLUSION

Night-time sleep duration, midday napping duration and bedtime were all independently associated with the risk of hyperglycaemia, and some of the associations between these sleep characteristics and hyperglycaemia were gender- and age-dependent.

A prospective observational study to investigate the correlation analysis between neonatal hyperbilirubinemia and deafness gene: Study protocol clinical trial (SPIRIT compliant)

INTRODUCTION

There are many studies on the relationship between serum levels of hyperbilirubinemia and hearing impairment. However, the mechanism of hyperbilirubinemia on auditory impairment is not clear.

METHODS AND ANALYSIS

A total of 1000 children with hyperbilirubinemia who are mainly indirectly elevated bilirubin in the full-term neonatal ward of Xiamen Children's Hospital from March 2020 to September 2020 will be enrolled. Using second-generation high-throughput sequencing technology, 127 deaf-related genes were sequenced from the collected samples. At the same time, physical audiometry was performed on the selected persons and audiometry data were recorded.

DISCUSSION

In this study, we will combine gene sequencing with clinical indications of hyperbilirubinemia to find the loci suitable for high-frequency pathogenic deafness related to hyperbilirubinemia, so as to provide early guidance for deafness gene screening in children with hyperbilirubinemia.

TRIAL REGISTRATION

Chinese Clinical trial registry: ChiCTR2000030075.

[Effects of parental rearing patterns and their consistency on the emotional and behavioral problems of preschool children]

Objective: To explore the effect of parental rearing patterns and their consistency on the emotional and behavioral problems of preschool children. Methods: From October to November 2017, 27 987 children aged 3 to 6 years old from 109 kindergartens in 11 cities of Hubei, Anhui and Jiangsu Provinces were selected by using the cluster sampling method. A total of 27 200 valid questionnaires which were completed by subjects' parents were collected. The emotional and behavioral problems of preschool children were collected by "strengths and difficulties questionnaire" and the parental rearing patterns were evaluated by the "Parental Behavior Scale". The differences in emotional and behavioral abnormality rates of preschool children with different characteristics were analyzed; with emotional and behavioral problems as dependent variables and parental support/participation and compulsion/hostility as independent variables, the multivariate logistic regression model was used to analyze the effect of parental rearing patterns and their consistency on the emotional and behavioral problems of preschool children. Results: The age of children was (4.35±0.96) years old, and 51.4% of children were 13 975 males. There were 24 634 (90.6%) urban children and 17 916 (65.9%) only children. Both parents with strong support/participation accounted for 14.9%, and those with poor support/participation accounted for 11.9%; both parents with strong compulsion/hostility accounted for 15.2%, and those with low compulsion/hostility accounted for 11.3%. The rates of emotional symptoms, conduct behavior, hyperactive behavior, peer interaction, total difficulty score, and abnormal prosocial behavior of preschool children were 9.5%, 9.5%, 18.2%, 24.5%, 11.2%, and 10.2%, respectively. The multivariate logistic regression model analysis showed that after adjusting for gender, only child, living area, family economic status, mother's age and education level, father's education level, and other factors, compared with fathers/mothers with strong support/participation and low compulsion/hostility and parents with strong support/participation and low compulsion/hostility, preschool children who had fathers/mothers with poor support/participation and strong compulsion/hostility or parents with poor support/participation and strong compulsion/hostility were more likely to have emotional symptoms, conduct behavior, hyperactive behavior, peer interaction, total difficulty score, and abnormal prosocial behavior (P<0.05). Conclusions: Parental rearing patterns and their consistency are related to the emotional and behavioral problems of preschool children.

A social cost-benefit analysis of two One Health interventions to prevent toxoplasmosis

Background

In the Netherlands, toxoplasmosis ranks third in disease burden among foodborne pathogens, with an estimated health loss of 1,900 Disability Adjusted Life Years and a cost-of-illness estimated at €44 million annually. We performed a Social Cost-Benefit Analysis (SCBA) to evaluate the net value of two potential interventions, freezing meat and improving biosecurity in pig farms, for the Dutch society.

Methods

We assessed the costs and benefits of the two interventions and compared them with the current practice of education, especially during pregnancy. A ‘minimum scenario’ and a ‘maximum scenario’ was assumed, using input parameters with least benefits to society and input parameters with most benefits to society, respectively.

Results

The freezing meat intervention was far more effective than the biosecurity intervention. Despite high freezing costs, freezing two meat products: steak tartare and mutton leg yielded net social benefits in both the minimum and maximum scenario, ranging from €10.6 million to €31 million for steak tartare and €0.6 million to €1.5 million for mutton leg. The biosecurity intervention would result in net costs in all scenarios ranging from €1 million to €2.5 millions.

Conclusions

From a public health perspective (i.e. reducing the burden of toxoplasmosis) freezing steak tartare and leg of mutton is to be considered.

Decreased Expression of TIM-3 on Th17 Cells Associated with Ophthalmopathy in Patients with Graves' Disease

Purpose:

Thyroid-associated Ophthalmopathy (TAO) is one of the most common orbital immunological diseases in adults. CD4+ helper T (Th) cells play important roles in the pathogenesis of TAO. But the mechanisms regulating CD4+ T cell activity is unclear. This study examines T cell immunoglobulin domain and mucin domain 3 (TIM-3) expression in helper T cell type 1 (Th1), Th17, and regulatory T cells in sufferers of TAO.

Methods:

Participants were divided into 3 groups: patients with TAO, patients with Graves’ disease but without orbitopathy (GD), and healthy control patients (HC). Peripheral blood samples were collected for each patient in the designated group. Flow cytometry methods assessed the frequency of Th1 (CD4+IFN-γ+), Th17 (CD4+IL-17+), regulatory T cells (CD4+CD25hiCD127lo), and TIM-3 protein expression. Mean fluorescence intensity (MFI) measured the magnitude of TIM-3 expression and the percentage of TIM-3+ cells for each patient.

Results:

Compared to the GD group, TAO patients possessed higher frequencies of Th1 and Th17 cells in peripheral blood samples. The percentage of TIM-3+ Th1 and Th17 cells was significantly lower in the TAO patients than the GD group. Across all patients sampled, TIM-3+ cell percentage negatively correlated with Th1 cell frequency. Th1 and Th17 cells exhibited significantly decreased expression of TIM-3 in TAO patients compared to healthy controls. Regulatory T cells showed little TIM-3 expression and we observed no significant differences in frequency between groups.

Conclusion:

These results suggest a role for TIM-3 in the regulation of Th1 and Th17 cells and the pathogenesis of Graves’ ophthalmopathy.

Vibrational spectroscopic study on feed molecular structure properties of oil-seeds and co-products from Canadian and Chinese bio-processing and relationship with protein and carbohydrate degradation fractions in ruminant systems

The objective of this study was to apply ATR-FTIR spectroscopy to reveal feed molecular structure properties of oil-seeds and co-products and relationship with protein and carbohydrate degradation fractions in ruminant systems. The oil-seeds and co-products were from both various bio-processing industries in Canada and China. The protein and carbohydrate degradation fractions were evaluated with updated CNCPS system. Results showed that in the co-products from canola processing industries there are strong relationship between 1) soluble true protein (PA2) fraction and the following protein molecular structure spectral characteristics; spectral peak area of amide I and amide II (r = 0.56, P = 0.001), area of amide I (r = 0.67, P < 0.001), height of amide I (r = 0.74, P < 0.001), amide I and II ratio (r = 0.57, P = 0.001), α-helix (r = 0.82, P < 0.001), and β-sheet (r = 0.61, P < 0.001), 2) slowly degradable true protein (PB2) fraction and height of amide I (r = -0.60, P = 0.001), α-helix (r = -0.72, P < 0.001), and β-sheet (r = -0.51, P = 0.004), 3) soluble fiber (CB2) fraction and α-helix and β-sheet height ratio (r = -0.63, P < 0.001), and 4) unavailable NDF (CC) fraction and height of amide I (r = 0.55, P = 0.002). These results indicated feed molecular structure spectral properties of the oil-seeds and co-products related to CNCPS protein and carbohydrate degradation fractions in ruminant systems.

Probing the Melting of a Two-Dimensional Quantum Wigner Crystal via its Screening Efficiency

One of the most fundamental and yet elusive collective phases of an interacting electron system is the quantum Wigner crystal (WC), an ordered array of electrons expected to form when the electrons' Coulomb repulsion energy eclipses their kinetic (Fermi) energy. In low-disorder, two-dimensional (2D) electron systems, the quantum WC is known to be favored at very low temperatures (T) and small Landau level filling factors (ν), near the termination of the fractional quantum Hall states. This WC phase exhibits an insulating behavior, reflecting its pinning by the small but finite disorder potential. An experimental determination of a T vs ν phase diagram for the melting of the WC, however, has proved to be challenging. Here we use capacitance measurements to probe the 2D WC through its effective screening as a function of T and ν. We find that, as expected, the screening efficiency of the pinned WC is very poor at very low T and improves at higher T once the WC melts. Surprisingly, however, rather than monotonically changing with increasing T, the screening efficiency shows a well-defined maximum at a T that is close to the previously reported melting temperature of the WC. Our experimental results suggest a new method to map out a T vs ν phase diagram of the magnetic-field-induced WC precisely.