Detection of significant liver fibrosis in Chinese psoriasis patients receiving methotrexate: a comparison between transient elastography and liver histology

INTRODUCTION

Methotrexate (MTX) is effective for treating psoriasis and psoriatic arthritis, but its potential hepatoxicity remains a concern. Liver biopsy, the gold standard for detecting MTX-induced liver injury, is invasive and carries considerable risk. Transient elastography (TE) offers a non-invasive alternative for detecting advanced liver fibrosis. This study investigated the performance of TE in detecting MTX-induced liver fibrosis among Chinese psoriasis patients, compared with liver biopsy.

METHODS

This study included adult patients with clinical psoriasis. Liver stiffness measurement using TE was performed in patients receiving MTX. Exclusion criteria were known liver cirrhosis, positive viral hepatitis carrier status, or conditions influencing TE performance. Liver biopsy was performed when liver stiffness was ≥7.1 kilopascals (kPa) or when the total cumulative dose (TCD) of MTX was ≥3.5 g.

RESULTS

A total of 228 patients were screened; among 34 patients who met the inclusion criteria, nine (26.5%) had significant liver fibrosis (Roenigk grade ≥3a). The area under the receiver operating characteristic curve was 0.76 (95% confidence interval=0.59-0.93; P=0.021), indicating that TE had satisfactory performance in detecting liver fibrosis. A cut-off value of 7.1 kPa of liver stiffness yielded 100% sensitivity and 68% specificity. Liver fibrosis was not correlated with the TCD of MTX or the duration of MTX use; it was significantly correlated with obesity and diabetes status (body mass index ≥30 kg/m2, waist circumference ≥138 cm, and glycated haemoglobin level ≥7.8%).

CONCLUSION

Transient elastography is reliable and superior to the TCD for detecting liver fibrosis in Chinese psoriasis patients receiving MTX. Liver biopsy should be reserved for high-risk patients or patients with liver stiffness ≥11.7 kPa on TE.

Prediction model for haematoma after tissue expander placement: A retrospective cohort study of 7080 cases over 20 years

Haematoma is an early complication of tissue expander placement and can lead to infection, capsule contracture and various complications, hindering successful reconstruction. However, no scientific models can accurately predict the risk of haematoma following tissue expansion. Therefore, this study aimed to develop and validate a prediction model for haematoma following tissue expander placement. The medical records of patients who underwent expander placement between 2001 and 2021 were obtained from the clinical database of the Department of Plastic Surgery at the Xijing Hospital. A total of 4579 consecutive patients with 7080 expanders and 179 expanded pocket haematomas were analysed. Multivariate logistic regression analysis identified adult age (P = 0.006), male sex (P < 0.001), scar reconstruction (P = 0.019), perioperative hypertension (P < 0.001), face and neck location (P = 0.002) and activated partial thromboplastin time above the normal range (P < 0.001) as risk factors for haematoma. Therefore, these were included in the prediction model, and a nomogram was constructed. The discrimination of the nomogram was robust (area under the curve: 0.78; 95% confidence interval: 0.72-0.83). Further, the prediction model had a strong fit (Hosmer-Lemeshow test, P = 0.066) and maintained similar discrimination after considering performance optimism (bootstrapped area under the curve: 0.79; 95% confidence interval: 0.73-0.84). This clinical prediction model was created using a generalisable dataset and can be utilised to obtain valid haematoma predictions after expander placement, assisting surgeons in implementing preventive measures or interventions to reduce the occurrence of haematoma.

Itraconazole inhibits tumor growth via CEBPB-mediated glycolysis in colorectal cancer

Advanced colorectal cancer (CRC) is characterized by a high recurrence and metastasis rate, which is the primary cause of patient mortality. Unfortunately, effective anti-cancer drugs for CRC are still lacking in clinical practice. We screened FDA-approved drugs by utilizing targeted organoid sequencing data and found that the antifungal drug itraconazole had a potential therapeutic effect on CRC tumors. However, the effect and mechanism of itraconazole on CRC tumors have not been investigated. A cell line-derived xenograft model in tumor-bearing mice was established and single-cell RNA sequencing was performed on tumor samples from four mice with or without itraconazole treatment. The proportion of cell populations and gene expression profiles was significantly different between the two groups. We found that itraconazole could inhibit tumor growth and glycolysis. We revealed that CEBPB was a new target for itraconazole, and that silencing CEBPB could repress CRC glycolysis and tumor growth by inhibiting ENO1 expression. Clinical analysis showed that CEBPB expression was obviously elevated in CRC patients, and was associated with poor survival. In summary, itraconazole treatment remodeled cell composition and gene expression profiles. Itraconazole inhibited cell glycolysis and tumor growth via the CEBPB-ENO1 axis. In this study, we illustrate a new energy metabolism mechanism for itraconazole on tumor growth in CRC that will provide a theoretical basis for CRC targeting/combination therapy.

[Study of the predictive role of serum HBV RNA on HBeAg serological conversion in children with chronic hepatitis B]

Objective: To investigate the role of serum hepatitis B virus RNA (HBV RNA) in predicting HBeAg serological conversion in children with chronic hepatitis B. Methods: 175 children aged 1~17 years with chronic hepatitis B who received interferon α (IFNα) for 48 weeks were selected. Patients were divided into HBeAg seroconversion and non-conversion based on whether HBeAg seroconversion occurred at 48 weeks of treatment.T-test and Mann-Whitney U test were used to compare between groups; chisquare test or Fisher exact probability method was used to compare the frequency between groups of classified variables; and Pearson correlation was used to analyze the correlation between indicators. Univariate and multivariate logistic regression analyses were used to identify influencing factors associated with HBeAg serological conversion. The predictive effect of HBV RNA, HBV DNA, and HBsAg on HBeAg serological conversion was compared and analyzed by the receiver operating characteristic curve (ROC). Results: The seroconversion rate of HBeAg at 48 weeks was 36.0% (63/175). The reduction in HBVRNA levels from baseline to the 12th, 24th, 36th, and 48th weeks of antiviral therapy was significantly greater in the HBeAg serological conversion group than that in the non-conversion group, and the difference was statistically significant between the two groups (P < 0.05). Univariate and multivariate regression analyses showed that age and a decline in HBV RNA levels at week 12 were independent predictors of HBeAg serological conversion. The area under the ROC curve (AUROC) of HBV RNA decline at week 12 was 0.677(95% CI∶0.549-0.806, P = 0.012), which was significantly better than the same period of AUROC of HBV DNA (0.657, 95% CI∶0.527-0.788, P = 0.025) and HBsAg (0.660, 95% CI∶0.526-0.795, P = 0.023) decline. HBV RNA levels decreased (>1.385 log10 copies/ml) at week 12, with a positive predictive value of 53.2%, a negative predictive value of 72.2%, a sensitivity of 77.4%, and a specificity of 57.9% for HBeAg seroconversion. Conclusion: HBV RNA level lowering during the 12th week of antiviral therapy can serve as an early predictor marker for HBeAg serological conversion in children with chronic hepatitis B.

Reconstruction of Hemifacial Congenital Giant Nevus with Pre-expanded Scalp Flaps and Deltopectoral Skin Flaps

BACKGROUND

The hemifacial congenital giant nevus impacts both physical and mental health of the patients. Excision is typically the most suitable option in these situations, but reconstructing the subsequent surgical defects is always a serious challenge.

METHODS

Between February 2012 and January 2021, a retrospective review of 4 patients who suffered from hemifacial congenital giant nevus was conducted, and they were treated by pre-expanded scalp flap and deltopectoral flap simultaneously. All patients receive tissue expansion, nevus resection, expanded skin flap transfer, and pedicle division.

RESULTS

Four patients with hemifacial congenital giant nevi were successfully treated with no major complications. One patient with a transferred deltopectoral flap experienced distal necrosis of the flap, and healed after dressing changes. No recurrence of the nevus was found during the follow-up period, and the transferred skin flaps match well with facial skin in contour and color.

CONCLUSION

This modified pre-expanded scalp flap combined with a deltopectoral flap provides an easy and reliable way for hemifacial reconstruction in patients with a congenital giant nevus.

Multi-camera imaging to characterize jet and liner uniformity on the Plasma Liner Experiment (PLX)

At Plasma Liner Experiment, a set of 36 coaxial plasma guns are deployed quasi-uniformly over a 9 ft diameter spherical chamber and are used to form a high-Z spherically compressive plasma liner. Simulations indicate that for the concept to ultimately achieve optimal target density and temperature, a high degree of timing uniformity is required between all guns. To aid in quantifying and correcting gun-to-gun nonuniformities, a key diagnostic will consist of up to six fisheye-view CCD cameras positioned inside the main chamber such that each has all plasma guns within its view. The individual cameras can be triggered at different times to determine each plasma jet's muzzle velocity and structure for different operating conditions. This camera array is currently under development, and the implementation needs and challenges for this camera array are discussed here. Additionally, we detail the analysis methodology for determining jet-to-jet uniformity deviations and how we can correct them, thereby improving overall liner uniformity.

Experimental Measurements of Ion Diffusion Coefficients and Heating in a Multi-Ion-Species Plasma Shock

Collisional plasma shocks generated from supersonic flows are an important feature in many astrophysical and laboratory high-energy-density plasmas. Compared to single-ion-species plasma shocks, plasma shock fronts with multiple ion species contain additional structure, including interspecies ion separation driven by gradients in species concentration, temperature, pressure, and electric potential. We present time-resolved density and temperature measurements of two ion species in collisional plasma shocks produced by head-on merging of supersonic plasma jets, allowing determination of the ion diffusion coefficients. Our results provide the first experimental validation of the fundamental inter-ion-species transport theory. The temperature separation, a higher-order effect reported here, is valuable for advancements in modeling HED and ICF experiments.

The tumor microenvironment in gastrointestinal adenocarcinomas revealed a prognostic and immunotherapeutic biomarker

Accumulated evidence has elucidated that the tumor microenvironment (TME) is great of clinical significance in predicting survival outcomes and therapeutic efficacy. Nonetheless, few studies have investigated the prognostic and immunotherapeutic signature correlated with TME phenotypes in gastrointestinal adenocarcinomas (GIAC). Here, by estimating the TME pattern of immune infiltration and expression in over 1,000 GIAC patients, we revealed three TME subgroups and identified six key differential genes. To predict the TME phenotypes, TMEscore was established and validated to be an independent prognostic factor, where the high TMEscore was characterized by immune activation and response to immunotherapy and accompanied with favorable prognosis in GIAC. Furthermore, TMEscore was confirmed to predict prognosis and immunotherapeutic response in six datasets. In summary, depicting TME landscape of GIAC patients may be beneficial for interpreting survival and immunotherapeutic response, and provide new strategies for clinical treatment of GIAC.

circ-LDLRAD3 Knockdown Reduces Cisplatin Chemoresistance and Inhibits the Development of Gastric Cancer with Cisplatin Resistance through miR-588 Enrichment-Mediated SOX5 Inhibition

Background/Aims

Chemoresistance is a common event after cancer chemotherapy, which is associated with the deregulation of circular RNAs (circRNAs). The objective of this study was to clarify the role of circ-LDLRAD3 in cisplatin (DDP)-resistant gastric cancer (GC).

Methods

The expression of circ-LDLRAD3, miR-588, and SRY-box transcription factor 5 (SOX5) mRNA was detected by quantitative real-time polymerase chain reaction. Cell viability and the half maximal inhibitory concentration (IC₅₀) value were measured by CCK8 assay. Cell proliferation was assessed by colony formation and EdU assays. Cell apoptosis and cell invasion were assessed by flow cytometry assay and transwell assay, respectively. The expression of SOX5 protein was detected by Western blotting. A xenograft model was established to verify the role of circ-LDLRAD3 in vivo. Exosomes were isolated by differential centrifugation and identified by transmission electron microscopy and the expression of exosome-related proteins.

Results

circ-LDLRAD3 was overexpressed in DDP-resistant GC tissues and cells. circ-LDLRAD3 knockdown decreased the IC₅₀ of DDP-resistant cells and suppressed cell proliferation, survival and invasion. miR-588 was a target of circ-LDLRAD3, and miR-588 inhibition attenuated the inhibition of DDP resistance, proliferation, survival and invasion in DDP-resistant GC cells caused by circ-LDLRAD3 knockdown. SOX5 was a target of miR-588, and the inhibition of the DDP resistance, proliferation, survival and invasion of DDP-resistant GC cells by miR-588 restoration was largely rescued SOX5 overexpression. circ-LDLRAD3 knockdown inhibited DDP resistance and tumor growth in vivo. circ-LDLRAD3 was overexpressed in exosomes isolated from DDP-resistant GC cells.

Conclusions

circ-LDLRAD3 knockdown reduced DDP resistance and blocked the malignant development of DDP-resistant GC by modulating the miR-588/SOX5 pathway.

Identification and Validation of an m6A-Related LncRNA Signature to Predict Progression-Free Survival in Colorectal Cancer

The RNA methylation of N6 adenosine (m6A) plays a crucial role in various biological processes. Strong evidence reveals that the dysregulation of long non-coding RNAs (lncRNA) brings about the abnormality of downstream signaling in multiple ways, thus influencing tumor initiation and progression. Currently, it is essential to discover effective and succinct molecular biomarkers for predicting colorectal cancer (CRC) prognosis. However, the prognostic value of m6A-related lncRNAs for CRC remains unclear, especially for progression-free survival (PFS). Here, we screened 24 m6A-related lncRNAs in 622 CRC patients and identified five lncRNAs (SLCO4A1-AS1, MELTF-AS1, SH3PXD2A-AS1, H19 and PCAT6) associated with patient PFS. Compared to normal samples, their expression was up-regulated in CRC tumors from TCGA dataset, which was validated in 55 CRC patients from our in-house cohort. We established an m6A-Lnc signature for predicting patient PFS, which was an independent prognostic factor by classification analysis of clinicopathologic features. Moreover, the signature was validated in 1,077 patients from six independent datasets (GSE17538, GSE39582, GSE33113, GSE31595, GSE29621, and GSE17536), and it showed better performance than three known lncRNA signatures for predicting PFS. In summary, our study demonstrates that the m6A-Lnc signature is a promising biomarker for forecasting patient PFS in CRC.

Reconstruction of facial defects using a pre-expanded scalp flap: A description of the method used and outcomes of 43 patients

Background

A technique for reconstructing facial units with matching colour, similar texture and sufficient contour is ideal for patients with various facial defects. The current report aimed to present the experience of the authors in facial reconstruction using pre-expanded scalp flaps combined with laser hair removal.

Methods

From January 2014 to August 2021, 43 patients with different facial defects, such as post-burn scar and congenital nevus, were treated using this surgical technique that involved tissue expansion, scalp flap transfer and laser hair removal. Facial defects were artificially classified into three regions (forehead, n = 19; cheek, n = 15; and lips and chin, n = 9). Pedicle delaying and division were performed in patients who underwent reconstruction with pedicled flaps.

Results

Of the included patients, one presented with haematoma, one with infection and three had distal necrosis after expanded scalp flap transfer. The donor site was primarily closed in all patients. Further, all patients were successfully treated without major complications. The texture, colour and contour of the scalp flap after laser hair removal matched well with the surrounding skin tissues at 2–30-month follow-up.

Conclusion

Reconstruction using pre-expanded scalp flaps combined with laser hair removal is an effective and reliable option for facial reconstruction with excellent colour and texture match.

Induction of lncRNA NORAD accounts for hypoxia-induced chemoresistance and vasculogenic mimicry in colorectal cancer by sponging the miR-495-3p/ hypoxia-inducible factor-1α (HIF-1α)

Hypoxic microenvironment represents the hallmark of solid tumors including colorectal cancer (CRC) and facilitates angiogenesis and chemoresistance, leading to poor prognosis. lncRNA NORAD acts as an oncogenic gene to orchestrate cancer progression by regulating cell proliferation and migration. Notably, an emerging study corroborates the elevation of NORAD during hypoxic conditions in pancreatic cancer. Nevertheless, its biological role in hypoxia-evoked CRC remains unclear. Herein, enhanced expression of NORAD and hypoxia-inducible factor-1α (HIF-1α) was validated in CRC tissues. Furthermore, there was a positive association between NORAD and HIF-1α in CRC tissues. CRC cells exposed to hypoxia exhibited a stronger ability to form vasculogenic mimicry (VM) and resistance to 5-fluorouracil (5-FU), concomitant with higher expression of NORAD. NORAD knockdown restrained hypoxia-induced VM formation and VM marker VE-cadherin expression. Moreover, knockdown of NORAD counteracted CRC cell resistance to 5-FU by decreasing cell viability and increasing cell apoptosis. Additionally, NORAD loss reduced hypoxia-induced HIF-1α expression and subsequent epithelial-mesenchymal transition (EMT) by increasing E-cadherin and inhibiting N-cadherin expression. Intriguingly, HIF-1α overexpression reversed NORAD downregulation-mediated inhibition of VM formation and 5-FU resistance. There was a low expression of miR-495-3p in CRC tissues. Furthermore, NORAD could act as a competitive endogenous RNA of miR-495-3p to regulate HIF-1α. Importantly, inhibition of miR-495-3p muted the efficacy of NORAD loss in hypoxia-induced EMT, VM, and chemoresistance. Thus, the current data highlight that NORAD knockdown may antagonize hypoxia-triggered CRC malignancy by suppressing VM formation and chemoresistance by sponging miR-495-3p/HIF-1α to regulate EMT, supporting a promising therapeutic target for refractory hypoxia in CRC.

Step-by-step illustrated guide to central neck dissection

BACKGROUND

The incidence of thyroid carcinoma has been increasing worldwide and surgery is the primary treatment. Central compartment dissection of the neck is a very delicate procedure given the risks of recurrent laryngeal nerve injury and hypoparathyroidism.

METHODS

This paper gives a detailed description of this surgical technique in a patient affected by papillary carcinoma of the thyroid gland, supported by highly representative iconographic materials from a tertiary department.

RESULTS

A stepwise description is provided, along with high-quality pictures and specific tips and tricks. Although neck dissection is a well-codified procedure, the fine details of this surgical technique are not currently available and are still the prerogative of the expert surgeon.

CONCLUSION

The central neck compartment contains several vulnerable structures; damage to these structures would affect patients' lives, possibly permanently. Anatomical knowledge and standardisation are needed for all surgeons, particularly new surgeons (such as residents) who cannot rely simply on experience.

Fecitrate converted from Fe2O3 particles in coal-fired flue gas promoted microalgal biomass and lipid productivities

In order to reutilize Fe₂O₃ particles in flue gas from coal-fired power plant as a ferrum nutrient for improving microalgae growth, Na-Citrate was proposed to chelate FeCl₃ derived from Fe₂O₃ and HCl reactions to promote biomass and lipid productivities of Chlorella PY-ZU1. Fe-Citrate gave much higher biomass and lipid productivities than FeCl₃, Fe-EDTA, Fe-DTPA and Fe-HEDTA, because organic chelator prevented Fe³⁺ from depositing, lower stability constant resulted in easier dissociation of ferric chelate, smaller chelate facilitated Fe²⁺ (reduced from Fe³⁺) transportation through cell membranes. The biomass growth and photosynthetic capacity of Chlorella PY-ZU1 cultivated with Fe-Citrate (converted from Fe₂O₃ particles) medium were similar to those with commercial ferric ammonium citrate medium. The biomass and lipid productivities of Chlorella PY-ZU1 cultivated with 5 mg L^-1 Fe-Citrate medium were 1.30 and 1.72 times, respectively, higher than those with FeCl₃ growth medium.

Adoptive transfer of immunomodulatory M2 macrophages suppresses experimental autoimmune encephalomyelitis in C57BL/6 mice via blockading NF-κB pathway

Macrophages play important roles in multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), and M2 macrophage may have anti-inflammatory effects. In this study, we elucidated the roles of M1 and M2 macrophages in the pathogenesis of EAE and the effects of treatment with M2 macrophages that target certain proinflammatory cytokines and with immunomodulatory preparations that beneficially influence the disease course. We found macrophages increased at the onset of clinical signs in the EAE group, consistent with an increased proportion of M1 macrophages and low numbers of M2 macrophages. As the disease progressed and the symptoms worsened, M1 macrophages decreased and M2 macrophages gradually increased until the peak. In the recovery stage, M2 macrophages gradually decreased. Treatment with M2 macrophages inhibited the nuclear factor kappa B (NF-κB) pathway, alleviated the symptoms of EAE, reduced inflammatory cell infiltration and demyelination in the central nervous system and decreased the numbers of macrophages in the spleens. BAY-11-7082, an NF-κB blocking agent, could reduce the total number of macrophages both in vivo and in vitro, effectively prevented EAE development and significantly inhibited EAE symptoms in mice. Our study demonstrates that macrophages may play a crucial role in the pathogenesis of EAE, while M2 macrophages have anti-inflammatory effects. Transfer of M2 macrophages to EAE mice can block the NF-κB pathway successfully and relieve EAE symptoms. Application of NF-κB blockers is useful in the prevention and treatment of EAE.

Knockdown of circ_0000512 Inhibits Cell Proliferation and Promotes Apoptosis in Colorectal Cancer by Regulating miR-296-5p/RUNX1 Axis

Background

Colorectal cancer (CRC) is one of the leading causes of cancer-related death worldwide. Increasing evidence showed that circular RNAs (circRNAs) played critical roles in the progression of CRC. However, the effects and underlying mechanisms of circ_0000512 in CRC progression remain unclear.

Methods

The expression levels of circ_0000512, microRNA-296-5p (miR-296-5p) and runt-related transcription factor 1 (RUNX1) were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability, colony formation, cell cycle distribution and cell apoptosis were detected by Cell Counting Kit-8 (CCK-8) assay, colony formation assay and flow cytometry analysis, respectively. Western blot assay was utilized to measure the protein expression of Cyclin D1, Cleaved Caspase-3 and RUNX1. The interaction between miR-296-5p and circ_0000512 or RUNX1 was predicted by starBase and verified by dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay and RNA pull-down assay. The mice xenograft model was established to explore the function of circ_0000512 in vivo.

Results

The expression of circ_0000512 was increased in CRC tissues and cells. Knockdown of circ_0000512 suppressed cell viability and colony formation and arrested the cells at the G0/G1 phase while it accelerated apoptosis in CRC cells. Mechanistically, circ_0000512 could increase RUNX1 expression by acting as a molecular sponge of miR-296-5p in CRC cells. Furthermore, miR-296-5p downregulation or RUNX1 overexpression reversed the anti-proliferation and pro-apoptosis effects caused by circ_0000512 knockdown in CRC cells. In addition, circ_0000512 interference inhibited tumor growth by upregulating miR-296-5p and downregulating RUNX1 in vivo.

Conclusion

Knockdown of circ_0000512 inhibited cell proliferation and induced apoptosis in CRC cell by regulating miR-296-5p/RUNX1 axis, which might provide a potential therapeutic target for CRC treatment.

Long noncoding RNA THOR is highly expressed in colorectal cancer and predicts a poor prognosis

Aim: Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. This study aimed to investigate the role of long noncoding RNA THOR in CRC. Materials & methods: The expression of THOR in 103 cases of CRC tissues and four CRC cell lines was examined by quantitative real-time PCR. Cell counting kit-8 and colony formation assays were applied to detect cell proliferation, and flow cytometry was used for testing cell cycle and apoptosis of CRC. Results: We found that THOR was highly expressed in CRC and correlated with tumor node metastasis stage, histological subtype, tumor size and differentiation and survival in CRC patients. Meanwhile, knockdown of THOR significantly suppressed cell proliferation and cell cycle of CRC, whereas promoted cell apoptosis. Conclusion: Our findings suggest that THOR is an oncogenic long noncoding RNA in CRC and a potential prognostic biomarker for this cancer.

Policy on Characterization of Antibodies Used in Immunochemical Methods of Analysis for Mycotoxins and Phycotoxins

The purpose of this document is to provide a policy on antibody characterization for conducting AOAC collaborative studies for immunochemical methods submitted for AOAC®Official MethodsSM Program status. The policy defines recommended information and characteristics to be provided by the Study Director, in the protocol of the collaborative study, for approval by AOAC. The document specifies parameters for characterization of antibodies used as biological reagent in the protocol of validation of immunochemical methods for the determination of mycotoxins and phycotoxins. These recommendations are applicable to the validation of any method, whether proprietary or non-proprietary, that is submitted to AOAC for Official Methods of AnalysisSM status recognition.

Determining Metastable Ion Lifetime and History through Wave-Particle Interaction

Laser-induced fluorescence (LIF) performed on metastable ions is frequently used to probe the dynamics of ground-state ion motions in many laboratory plasmas. However, these measurements place restrictions on the metastable ion lifetime. Metastable states are produced from direct ionization of neutral atoms as well as ions in other electronic states, of which the former will only faithfully represent processes that act on the ion dynamics in a time shorter than the metastable lifetime. We present here the first experimental study of this type of systematic effect using wave-particle interaction in an argon multidipole plasma. The metastable lifetime and relative fraction of metastables produced from preexisting ions, necessary for correcting the LIF measurement errors, can be determined by fitting the experimental results with the theory we propose.

Spermidine enhanced resistance of Chlorella to high levels of CO2 and light intensity for improving photosynthetic growth rate

In order to promote the photosynthetic growth rate of Chlorella in the presence of flue gas CO₂ from coal-fired power plants, spermidine was first used to enhance cellular resistance to a high CO₂ concentration (15%) and high light intensity (30 000 lux). It was found that low concentrations (100–300 μM) of spermidine significantly enhanced the photosynthetic growth rate of Chlorella. The accelerated cell division decreased the cell diameter from 3.64 μm to 2.71 μm and the fractal dimension from 1.60 to 1.49, and the activity of total superoxide dismutase (T-SOD) increased from 0.48 U mL⁻¹ to 5.33 U mL⁻¹. Expression levels of key enzymes of photosystems I and II, ATP synthase and transportase markedly increased, thereby enhancing the electron transport and energy supply that reduced oxidative damage. Finally, an enhanced cellular resistance to the high CO₂ concentration and high light intensity increased the biomass yield from 0.11 g L⁻¹ to 1.71 g L⁻¹ (300 μM).

Spermidine enhanced resistance of Chlorella to high levels of CO₂ and light intensity.

Evaluating the effectiveness of a preclinical practice of tooth preparation using digital training system: A randomised controlled trial

PURPOSE

This study aimed to evaluate the effectiveness of preclinical training on ceramic crown preparation using digital training system compared with traditional training method.

MATERIALS AND METHODS

A sample of 66 participating fourth-year undergraduate dental students were randomly assigned to one of two groups for ceramic crown preparation: experimental group as trained using digital method with Online Peer-Review System (OPRS) and Real-time Dental Training and Evaluation System (RDTES); control group as trained using traditional method with instructor demonstration and evaluation. At the completion of training periods, both groups performed the preparation of ceramic crown of upper left central incisor, which were blindly scored by the experienced instructors under the pre-defined assessment criteria. The results of both were compared using Student's t-test or Wilcoxon signed rank test. The level of significance was P < .05. The questionnaires regarding the benefits or drawbacks of digital training system were answered by the students of experimental group.

RESULTS

Five of 15 items in the assessment outcome of the digital group were significantly better than the traditional group. The questionnaire results from the students of the experimental group indicated 96.97% of the students agreed or strongly agreed that using digital training system could better improve the practical ability than traditional method. The total scores of practical results were significantly positively correlated with the points of the questionnaires.

CONCLUSION

The digital training system with OPRS and RDTES might be a good alternative to the traditional training method in the preclinical course of dental practice.

Appropriate cyclic tensile strain promotes biological changes of cranial base synchondrosis chondrocytes

OBJECTIVES

This study was designed to clarify biological changes of cranial base synchondrosis chondrocytes (CBSCs) upon cyclic tensile strain (CTS) loading which simulated orthopaedic mechanical protraction on cranial base synchondroses (CBS).

MATERIAL AND METHODS

A two-step digestion method was used to isolate CBSCs obtained from 1-week-old Sprague Dawley rats. Immunohistochemical staining of type II collagen and Sox9 was conducted to identify chondrocytes. A CTS of 1 Hz and 10% elongation was applied to the second passage of CBSCs by FX-5000™ Tension System for 24 hours. The control group kept static at the same time. The expression levels of extracellular matrix (Acan, Col1a1, Col2a1 and Col10a1) and key regulatory factors (Sox9, Ihh and PTHrP) were detected by quantitative real-time RT-PCR.

RESULTS

Positive staining of type II collagen and Sox9 was detected in the isolated CBSCs. The relative expression level of Acan, Col2a1, Col10a1, Sox9 and Ihh in the CTS-loading group was 1.85-fold, 2.19-fold, 1.53-fold, 6.62-fold, and 1.39-fold, respectively, as much as that in the control group, which had statistical significance (P<.05). There was no statistical difference (P>.05) in the expression of Col1a1 and PTHrP.

CONCLUSIONS

A CTS of 1 Hz and 10% elongation for 24 hours had positive effects on chondrocyte proliferation, phenotype maintenance and cartilage matrix synthesis.

MicroRNA-126 deficiency enhanced the activation and function of CD4+ T cells by elevating IRS-1 pathway

Recent evidence has shown that microRNA-126 (miR-126) has been involved in the development and function of immune cells, which contributed to the pathogenesis of related clinical diseases. However, the potential role of miR-126 in the development and function of CD4+ T cells remains largely unknown. Here we first found that the activation and proliferation, as well as the expression of interferon (IFN)-γ, of CD4+ T cells from miR-126 knock-down (KD) mice using the miRNA-sponge technique were enhanced significantly in vitro, compared with those in CD4+ T cells from wild-type (WT) mice. To monitor further the possible effect of miR-126 deficiency on the function of CD4+ T cells in vivo, we used dextran sulphate sodium (DSS)-induced murine model of acute autoimmune colitis and found that miR-126 deficiency could elevate the pathology of colitis. Importantly, the proportion of CD4+ T cells in splenocytes increased significantly in miR-126KD mice. Moreover, the expression levels of CD69 and CD44 on CD4+ T cells increased significantly and the expression level of CD62L decreased significantly. Of note, adoptive cell transfer assay showed that the pathology of colitis was more serious in carboxyfluorescein succinimidyl ester (CFSE)-labelled miR-126KD CD4+ T cell-transferred group, compared with that in the CFSE-labelled WT CD4+ T cells transferred group. Consistently, the expression levels of CD69 and CD44 on CFSE+ cells increased significantly. Furthermore, both the proliferation and IFN-γ secretion of CFSE+ cells also increased significantly in the CFSE-labelled miR-126KD CD4+ T cell-transferred group. Mechanistic evidence showed that the expression of insulin receptor substrate 1 (IRS-1), as a functional target of miR-126, was elevated in CD4+ T cells from miR-126KD mice, accompanied by altered transduction of the extracellular regulated kinase, protein B (AKT) and nuclear factor kappa B (NF-κB) pathway. Our data revealed a novel role in which miR-126 was an intrinsic regulator in the function of CD4+ T cells, which provided preliminary basis for exploring further the role of miR-126 in the development, function of CD4+ T cells and related clinical diseases.

Germline transformation of the western corn rootworm, Diabrotica virgifera virgifera

The western corn rootworm (WCR), a major pest of maize, is notorious for rapidly adapting biochemically, behaviourally and developmentally to a variety of control methods. Despite much effort, the genetic basis of WCR adaptation remains a mystery. Since transformation-based applications such as transposon tagging and enhancer trapping have facilitated genetic dissection of model species such as Drosophila melanogaster, we developed a germline-transformation system for WCR in an effort to gain a greater understanding of the basic biology of this economically important insect. Here we report the use of a fluorescent-marked Minos element to create transgenic WCR. We demonstrate that the transgenic strains express both an eye-specific fluorescent marker and piggyBac transposase. We identified insertion-site junction sequences via inverse PCR and assessed insertion copy number using digital droplet PCR (ddPCR). Interestingly, most WCR identified as transgenic via visual screening for DsRed fluorescence proved to carry multiple Minos insertions when tested via ddPCR. A total of eight unique insertion strains were created by outcrossing the initial transgenic strains to nontransgenic WCR mates. Establishing transgenic technologies for this beetle is the first step towards bringing a wide range of transformation-based tools to bear on understanding WCR biology.

Determination of an optimal dosing schedule for combining Irinophore C™ and temozolomide in an orthotopic model of glioblastoma

Our laboratory reported that Irinophore C™ (IrC™; a lipid-based nanoparticulate formulation of irinotecan) is effective against an orthotopic model of glioblastoma (GBM) and that treatment with IrC™ was associated with vascular normalization within the tumor. Here, the therapeutic effects of IrC™ when used in combination with temozolomide (TMZ) in concurrent and sequential treatment schedules were tested. It was anticipated that IrC™ engendered vascular normalization would increase the delivery of TMZ to the tumor and that this would be reflected by improved treatment outcomes. The approach compared equally efficacious doses of irinotecan (IRN; 50 mg/kg) and IrC™ (25 mg/kg) in order to determine if there was a unique advantage achieved when combining TMZ with IrC™. The TMZ sensitive U251MG(O) cell line (null expression of O-6-methylguanine-DNA methyltransferase (MGMT)) modified to express the fluorescent protein mKate2 was inoculated orthotopically into NOD.CB17-SCID mice and treatment was initiated 14 days later. Our results demonstrated that IrC™ and TMZ administered concurrently resulted in optimal treatment outcomes, with 50% long term survivors (>180 days) in comparison to 17% long term survivors in animals treated with IRN and TMZ or TMZ alone. Indeed, the different treatments resulted in a 353%, 222% and 280% increase in median survival time (MST) compared to untreated animals for, respectively, IrC™ combined with TMZ, IRN combined with TMZ, and TMZ alone. When TMZ was administered after completion of IRN or IrC™ dosing, an increase in median survival time of 167-174% was observed compared to untreated animals and of 67% and 74%, respectively, when IRN (50 mg/kg) and IrC™ (25mg/kg) were given as single agents. We confirmed in these studies that after completion of the Q7D×3 dosing of IrC™, but not IRN, the tumor-associated vascular was normalized as compared to untreated tumors. Specifically, reductions in the fraction of collagen IV-free CD31 staining (p<0.05) and reductions in tumor vessel diameter were observed in tumors from IrC™-treated animals when compared to tumors from untreated or IRN treated animals. Analysis by transmission electron microscopy of the ultra-structure of tumors from IrC™-treated and untreated animals revealed that tumor-associated vessels from treated animals were smaller, more organized and exhibited a morphology comparable to normal blood vessels. In conclusion, optimal treatment outcomes were achieved when IrC™ and TMZ were administered concurrently, whereas IrC™ followed by TMZ treatment given sequentially did not confer any therapeutic advantage.

Abstract P5-08-09: Synergistic cytotoxicity of digoxin and 5-fluorouracil in doxorubicin-resistant breast cancer cell lines

BACKGROUND: Metastatic breast cancer is the leading cause of cancer death for women in the US. Cytotoxic chemotherapy remains one of the most important systemic treatment options for breast cancer patients. To enhance the tumor response to chemotherapy, attention has been focused on agents that reverse multidrug resistance (MDR) and increase the sensitivity of tumor cells to chemical drugs. Although many reversal drugs have been identified in vitro, their clinical application has been limited due to their own toxicity. It was reported that 5 years after mastectomy, the recurrence rate of breast cancer among patients on cardiac glycoside therapy, namely digoxin or digitoxin, was almost 10 times lower as compared with those who were not on cardiac glycoside therapy. Digoxin has also been shown to inhibit hypoxia-inducible factors (HIF) and block lung metastasis in a breast cancer model. Interestingly, digoxin was demonstrated to stimulate cell death in various cell lines including breast cancer. Therefore the aim of this study was to examine the reversal effect of combined digoxin and 5-fluorouracil (5-FU) on MDR resistance in human breast cell lines MCF-7 and MDA-MB-231 in vitro, as well as its mechanism of action.

METHODS: Wild-type and doxorubicin-resistant ER-positive (MCF-7 and MCF-7/DoxR) and triple negative (MDA-MB-231 and MDA-231/DoxR) breast cancer lines were used for this study. We have previously shown that both doxorubicin-resistant cell lines are also cross-resistant to 5-FU. Cell viability of both resistant cancer cell lines to 5-FU, digoxin, and both 5-FU with digoxin were compared to control at 96 hours of incubation both in normoxia and hypoxia using MTT assay. Western blot was used to quantify the level of HIF-1α and p-glycoprotein (P-gP).

RESULTS: In both doxorubicin-resistant cell lines, sub-IC50 concentration of digoxin together with 5-FU significantly decreased the cell viabilities at 96 hours compared to single agent digoxin and 5-FU. Under both normoxic and hypoxic conditions, the same synergistic cytotoxic effects were demonstrated. Western blot revealed that HIF-1α and P-gP were decreased in both doxorubicin-resistant breast cancer cells treated with the digoxin and 5-FU combination compared to single agent digoxin or 5-FU.

CONCLUSION: The combination of digoxin and 5-FU demonstrates a synergistic cytotoxic effect in doxorubicin-resistant breast cancer cell lines that is maintained under hypoxic conditions. This is, at least in part, via the inhibitory effects on both HIF-1α and P-gP. The combination of digoxin and 5-FU could be an effective clinical treatment strategy to overcome MDR in breast cancer. A phase II clinical trial is ongoing to test this hypothesis in patients with doxorubicin-resistant metastatic breast cancer.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-08-09.

Preparation and Characterization of Melamine Modified Urea-Formaldehyde Foam

Melamine-urea-formaldehyde (MUF) foam was prepared using melamine modified urea formaldehyde resin. The effects of blowing agent, curing agent and surfactant on the properties of MUF foam such as apparent densities, compression strength, microstructure, fragility, limited oxygen index, thermal conductivity and formaldehyde emission were investigated. The best performance of MUF was obtained as the composition of blowing agent, curing agent and surfactant were 2.5%, 18% and 12% respectively. The water resistance of MUF foam, contents of foam's burning gas, curing mechanism and physical properties were also studied by Contact angle analyzer, TGA-FT-IR, FT-IR and 13C NMR.

Differential effect of long-term drug selection with doxorubicin and vorinostat on neuroblastoma cells with cancer stem cell characteristics

Numerous studies have confirmed that cancer stem cells (CSCs) are more resistant to chemotherapy; however, there is a paucity of data exploring the effect of long-term drug treatment on the CSC sub-population. The purpose of this study was to investigate whether long-term doxorubicin treatment could expand the neuroblastoma cells with CSC characteristics and histone acetylation could affect stemness gene expression during the development of drug resistance. Using n-myc amplified SK-N-Be(2)C and non-n-myc amplified SK-N-SH human neuroblastoma cells, our laboratory generated doxorubicin-resistant cell lines in parallel over 1 year; one cell line intermittently treated with the histone deacetylase inhibitor (HDACi) vorinostat and the other without exposure to HDACi. Cells' sensitivity to chemotherapeutic drugs, the ability to form tumorspheres, and capacity for in vitro invasion were examined. Cell-surface markers and side populations (SPs) were analyzed using flow cytometry. Differentially expressed stemness genes were identified through whole genome analysis and confirmed with real-time PCR. Our results indicated that vorinostat increased the sensitivity of only SK-N-Be(2)C-resistant cells to chemotherapy, made cells lose the ability to form tumorspheres, and reduced in vitro invasion and the SP percentage. CD133 was not enriched in doxorubicin-resistant or vorinostat-treated doxorubicin-resistant cells. Nine stemness-linked genes (ABCB1, ABCC4, LMO2, SOX2, ERCC5, S100A10, IGFBP3, TCF3, and VIM) were downregulated in vorinostat-treated doxorubicin-resistant SK-N-Be(2)C cells relative to doxorubicin-resistant cells. A sub-population of cells with CSC characteristics is enriched during prolonged drug selection of n-myc amplified SK-N-Be(2)C neuroblastoma cells. Vorinostat treatment affects the reversal of drug resistance in SK-N-Be(2)C cells and may be associated with downregulation of stemness gene expression. This work may be valuable for clinicians to design treatment protocols specific for different neuroblastoma patients.

A D-psicose 3-epimerase with neutral pH optimum from Clostridium bolteae for D-psicose production: cloning, expression, purification, and characterization

D-Tagatose 3-epimerase family enzymes can efficiently catalyze the epimerization of free keto-sugars, which could be used for D-psicose production from D-fructose. In previous studies, all optimum pH values of these enzymes were found to be alkaline. In this study, a D-psicose 3-epimerase (DPEase) with neutral pH optimum from Clostridium bolteae (ATCC BAA-613) was identified and characterized. The gene encoding the recombinant DPEase was cloned and expressed in Escherichia coli. In order to characterize the catalytic properties, the recombinant DPEase was purified to electrophoretic homogeneity using nickel-affinity chromatography. Ethylenediaminetetraacetic acid was shown to inhibit the enzyme activity completely; therefore, the enzyme was identified as a metalloprotein that exhibited the highest activity in the presence of Co²⁺. Although the DPEase demonstrated the most activity at a pH ranging from 6.5 to 7.5, it exhibited optimal activity at pH 7.0. The optimal temperature for the recombinant DPEase was 55 °C, and the half-life was 156 min at 55 °C. Using D-psicose as the substrate, the apparent K(m), k(cat), and catalytic efficiency (k(cat)/K(m)) were 27.4 mM, 49 s⁻¹, and 1.78 s⁻¹ mM⁻¹, respectively. Under the optimal conditions, the equilibrium ratio of D-fructose to D-psicose was 69:31. For high production of D-psicose, 216 g/L D-psicose could be produced with 28.8 % turnover yield at pH 6.5 and 55 °C. The recombinant DPEase exhibited weak-acid stability and thermostability and had a high affinity and turnover for the substrate D-fructose, indicating that the enzyme was a potential D-psicose producer for industrial production.

Adenoid assessment in paediatric patients: the role of flexible nasal endoscopy

Adenoid hypertrophy is the most common cause of nasal obstruction in paediatric patients. Over the years, various methods to assess the adenoid size were proposed such as the posterior rhinoscopy and the radiological examination of the nasopharynx. Nasal endoscopy was introduced for children in the 80&#x0027;s, and nowadays this is a known and diffuse method in routine practice. The purpose of this article is to describe the personal experience in the assessment of the adenoid size in children, with a particular regard to the flexible nasal endoscopy, and to analyse the literature reports. The personal technique is described in performing nasal endoscopy in paediatric patients, reporting advantages and possible disadvantages of the procedure. A retrospective analysis was conducted on 6036 children since 1999 to 2010. In most cases children fully collaborated to complete the exam. No major or minor complications (such as nose bleedings or other traumatic injuries) were observed. No topical intranasal decongestant, local or general anaesthesia were used in our series. In our opinion, nasal endoscopy in children is a reliable, safe, accurate, easily tolerated and dynamic diagnostic method to assess the adenoid size.

Cloning, expression, and characterization of a D-psicose 3-epimerase from Clostridium cellulolyticum H10

The noncharacterized protein ACL75304 encoded by the gene Ccel_0941 from Clostridium cellulolyticum H10 (ATCC 35319), previously proposed as the xylose isomerase domain protein TIM barrel, was cloned and expressed in Escherichia coli . The expressed enzyme was purified by nickel-affinity chromatography with electrophoretic homogeneity and then characterized as d-psicose 3-epimerase. The enzyme was strictly metal-dependent and showed a maximal activity in the presence of Co(2+). The optimum pH and temperature for enzyme activity were 55 °C and pH 8.0. The half-lives for the enzyme at 60 °C were 6.8 h and 10 min when incubated with and without Co(2+), respectively, suggesting that this enzyme was extremely thermostable in the presence of Co(2+) but readily inactivated without metal ion. The Michaelis-Menten constant (K(m)), turnover number (k(cat)), and catalytic efficiency (k(cat)/K(m)) values of the enzyme for substrate d-psicose were estimated to be 17.4 mM, 3243.4 min(-1), and 186.4 mM min(-1), respectively. The enzyme carried out the epimerization of d-fructose to d-psicose with a conversion yield of 32% under optimal conditions, suggesting that the enzyme is a potential d-psicose producer.

Comparison of NbCr2 and HfV2 C15 Laves Phases

The elastic properties, phase stability, and alloying behavior of NbCr2 and HfV2 C15 Laves phases have been investigated with a combined experimental and theoretical approach. Experimental results indicate that HfV2 has anomalous elastic properties as well as a structural instability, but NbCr2 does not. In addition, ternary phase fields of NbCr2 with V and HfV2 with Nb were examined experimentally, and they have substantially different alloying behavior. In order to understand these experimental phenomena, the total energy and electronic structure of C15 NbCr2 and HfV2 were calculated using the linear muffin-tin orbital method with the atomic sphere approximation. Calculation results suggest that the phase instability of HfV2 is induced by phonon softening, and the anomalous elastic properties of HfV2 appear to be attributed to a doubly degenerate electronic energy level with a linear dispersion relation very close to the Fermi level. Finally, density of states plots indicate that for HfV2, some bonding d-states are unoccupied while for NbCr2, all bonding and some anti-bonding d-states are occupied. The bonding difference may be responsible for the alloying behavior in the two Laves phase alloys. As a result, alloy design schemes are suggested for enhanced deformability in Laves phases.

The Effects of Film Thickness and Texture on the high and Low-Field stress Response of Lead Zirconate Titanate Thin Films

Lead zirconate titanate (PZT) thin films are currently employed in non-volatile ferroelectric memories (FRAM's) and are intended to be used as the active material in a number of microelectromechanical systems (MEMS). Several groups have reported that both the piezoelectric and dielectric characteristics of ferroelectric thin films improve with an increase of film thickness, though the reasons for those improvements are unclear. Previous investigations on the effects of biaxial mechanical stress indicate that non-180° domain wall motion is limited in PZT 52/48 films less than 0.5 μm thick. It is possible that some of the improvements of the dielectric and piezoelectric characteristics reported for thicker films (i.e. films thicker than 0.5 μm) are associated with an increase of extrinsic contributions to the properties. To evaluate domain wall mobility in thicker films, the high and low-field stress response of sol-gel PZT fabricated with either rapid thermal processing or conventional furnace annealing were investigated. Films with thicknesses ranging from 0.6 to 5.0 μm thick were measured as a function of applied biaxial stress (±110 MPa). It was found that for all films tested the changes of capacitance were on the order of 2–3%. High-field measurements showed: (1) the coercive field to be insensitive to applied stress, (2) remanent polarizations to decrease about 20% at the maximum applied tension, (3) remanent polarizations to increase less than 10% with applied compression, and (4) all changes to be reversible over the stress range investigated. These results suggest that extrinsic contributions are limited for the films tested.

Measurement of Effective Longitudinal Piezoelectric Coefficient of thin Films by Direct Piezoelectric Effect

This paper presents a new method for the measurement of the longitudinal piezoelectric coefficient of piezoelectric thin films using the direct piezoelectric effect. A uniform uniaxial stress was applied to the piezoelectric thin film by high-pressure gas and the induced charge was collected and measured by a charge integrator. The effective longitudinal piezoelectric coefficient of lead zirconate titanate (PZT) 52/48 thin films made by sol-gel processing was measured by this method. Undoped films typically have d33 values of ∼ 5 pC/N, while poled films have values up to 220 pC/N.

Processing and Properties of Mo5Si3 Single Crystals and Alloys

Among the high-temperature intermetallic systems, transition-metal silicides are attractive because of their high melting temperatures (many greater than 2273 K) and potential oxidation resistance. In particular, Mo5Si3 exhibits a very high melting point (2453 K) and also has a solubility range of 2 – 3 atomic percent, which can aid in processing and alloy design strategies. The focus of this study is to evaluate the processing and properties of Mo5Si3 and Mo5Si3-base ntermetallics. For the optimal baseline comparison, high-purity single crystals have been fabricated, and thermal and elastic properties have been experimentally measured. Although Mo5Si3 has a strong thermal expansion anisotropy, ts elastic anisotropy factors and the Poisson's ratios indicate that Mo5Si3 is less anisotropic in elasticity. The combination of the thermal and elastic properties has been employed to calculate the thermal residual stress and to explain the potential for grain boundary cracking during processing. Room temperature Vickers indentation tests of Mo5Si3 have been performed. The orientation dependence of hardness and fracture toughness of Mo5Si3 single crystals have been obtained. The corresponding deformation and fracture modes have been revealed by microscopy studies. Finally, micro- and macroalloyed Mo5Si3 with aluminum and boron will be briefly explored with property assessments.

Thickness Dependence of the Electrical Properties of Sol-Gel Derived Lead Zirconate Titanate Thin Films with (111) and (100) Texture

Crack-free (111) and (100)-textured Pb(Zr0.52Ti0.48)O3 films with thicknesses ranging from 0.25 to 2.5 μm were prepared using a methoxyethanol-based precursor solution, multiple spin-coating and multiple crystallization steps. The thickness dependence of the dielectric, ferroelectric and piezoelectric properties were investigated on both (111) and (100) oriented PZT films. In both cases, the degree of preferred orientation did not change with thickness. It is found that the dielectric constant, remanent polarization and piezoelectric coefficients (d33 and d31) increase with increasing film thickness. The (100)-textured film showed higher dielectric constant but lower remanent polarization relative to (111) textured film. 1 μm was identified to be a critical thickness that marks the change of dielectric, ferroelectric and piezoelectric behaviors as a function of thickness.