Bioinspired Passive Tactile Sensors Enabled by Reversible Polarization of Conjugated Polymers.

Tactile perception plays a vital role for the human body and is also highly desired for smart prosthesis and advanced robots. Compared to active sensing devices, passive piezoelectric and triboelectric tactile sensors consume less power, but lack the capability to resolve static stimuli. Here, we address this issue by utilizing the unique polarization chemistry of conjugated polymers for the first time and propose a new type of bioinspired, passive, and bio-friendly tactile sensors for resolving both static and dynamic stimuli. Specifically, to emulate the polarization process of natural sensory cells, conjugated polymers (including poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), polyaniline, or polypyrrole) are controllably polarized into two opposite states to create artificial potential differences. The controllable and reversible polarization process of the conjugated polymers is fully in situ characterized. Then, a micro-structured ionic electrolyte is employed to imitate the natural ion channels and to encode external touch stimulations into the variation in potential difference outputs. Compared with the currently existing tactile sensing devices, the developed tactile sensors feature distinct characteristics including fully organic composition, high sensitivity (up to 773 mV N-1), ultralow power consumption (nW), as well as superior bio-friendliness. As demonstrations, both single point tactile perception (surface texture perception and material property perception) and two-dimensional tactile recognitions (shape or profile perception) with high accuracy are successfully realized using self-defined machine learning algorithms. This tactile sensing concept innovation based on the polarization chemistry of conjugated polymers opens up a new path to create robotic tactile sensors and prosthetic electronic skins.

Accurate Boron Determination in Tourmaline by Inductively Coupled Plasma Mass Spectrometry: An Insight into the Boron-Mannitol Complex-Based Wet Acid Digestion Method.

Tourmaline, a boron-bearing mineral, has been extensively applied as a geothermometer, provenance indicator, and fluid-composition recorder in geological studies. In this paper, the decomposition capability of an HF-HNO3-mannitol mixture for a tourmaline sample was investigated in detail for the first time, and a wet acid digestion method based on the boron-mannitol complex for accurate boron determination in tourmaline by inductively coupled plasma mass spectrometry (ICP-MS) was proposed. With a digestion temperature of 140 °C, tourmaline samples of 25 mg (±0.5 mg) can be completely decomposed by a ternary mixture, which consisted of 0.6 mL of HF, 0.6 mL of HNO3, and 0.7 mL of 2% mannitol (wt.), via a continuous heating treatment of 36 h. Following gentle evaporation at 100 °C, the sample residues were re-dissolved using 2 mL of 40% HNO3 solution (wt.) and diluted to about 2.0 × 105-fold by a two-step method using 2% HNO3 solution (wt.). The boron contents in a batch of parallel tourmaline samples were then determined by ICP-MS, and results showed that the boron concentration levels were in a range of 3.20-3.44% with determination RSDs less than 4.0% (n = 5). It was found that the boron concentrations obtained at the mass of 10B were comparable with results from the measurements at the mass of 11B. This revealed that the usage of 2% mannitol with a quantity as high as 0.7 mL in this developed approach did not exhibit significant effect on the quantification accuracy of boron at the mass of 11B. It was also found that the processes including fluoride-forming prevention and fluoride decomposition deteriorated the boron-reserving efficiency of mannitol for tourmaline, causing the averaged boron contents to vary from 2.25% to 3.57% (n = 5). Furthermore, the stability of the boron-mannitol complex under 185 °C by applying the laboratory high pressure-closed digestion method was evaluated, which showed that there existed a 60.36% loss of boron compared to that under 140 °C by using this proposed approach. For this ternary mixture, the tourmaline decomposing efficiency was found to be weakened prominently using 100 °C as the digestion temperature, and tourmaline powders can be observed even after 72 h of continuous heating with B contents within 1.09-1.23% (n = 5). To assess the accuracy of this developed method, the boron recovery of anhydrous lithium tetraborate was studied. It was found that the boron recoveries were within 96.59-102.12% (RSD < 1%, n = 5), demonstrating the accuracy and reliability of this proposed method, which exhibits advantages of high B preserving efficiency, and giving concentration information of both B and trace elements simultaneously. By applying such a boron-mannitol complex-based wet acid digestion method, the chemical composition of boron and trace elements in three tourmaline samples from different pegmatites were quantified, which provided valuable information to distinguish regional deposits and the associated evolution stages.

In-Depth Method Investigation for Determination of Boron in Silicate Samples Using an Improved Boron-Mannitol Complex Digestion Method by Inductively Coupled Plasma Mass Spectrometry.

In this paper, a boron-mannitol complex wet acid digestion method proposed for the accurate determination of boron in silicate samples by inductively coupled plasma mass spectrometry (ICP-MS) was investigated in detail for the first time. With the addition of 50 µL of mannitol (2% wt.) into the mixture of 0.6 mL of concentrated HF and 30 µL of concentrated HNO3, the 50 mg of silicate sample was effectively decomposed after being heated overnight with optional pre-ultrasonic treatment. Following fluoride formation prevention by 8% HNO3 (wt.) and fluoride decomposition using 6% HCl (wt.), the samples were fluxed in 2.0 mL of 40% HNO3 (wt.) for 4 h and aged overnight. By diluting 1000-fold using 2% HNO3 (wt.) solution, the samples were directly quantified by an ICP-MS, showing boron recoveries of the standard materials including diabase W-2, basalt JB-2a, and rhyolite JR-2 in the range of 95.5-105.5% (n = 5). For this wet acid method, it was found that the contents of boron had no obvious difference under digestion temperatures of 65, 100, and 140 °C. It was also found that the ICP-MS quantification accuracy deteriorated at the mass of 11B when boron content was about 7250 ng yielding positive bias with average recoveries of 115.5-119.8% (n = 5), while the determination results remained unaffected at the mass of 10B. Furthermore, the digestion efficiency of boron by laboratory high-pressure closed digestion method was assessed. The boron recoveries with samples treated by the high-pressure closed digestion method were found to vary within 49.5-98.0% (n = 5) and even lowered down to 31.1% when skipping pressure relief procedure. The long-term quantification stability study showed that the boron content generally declined in one month for the high-pressure closed digestion method and exhibited no significant changes for the proposed method. By applying such an improved boron-mannitol complex digestion method, the boron concentration in the studied silicate standard materials were accurately determined, providing critical data for further boron isotope analyses and associated geochemical studies. This in-depth method investigation for silicate boron determination demonstrates the feasibility of this boron-mannitol complex strategy under a wide digestion temperature of 65-140 °C, and also sheds light on the extensive applications of boron as a geological tracer.

Assessing Chinese governance low-carbon economic peer effects in local government and under sustainable environmental regulation.

The current study developed a systematic analytical framework to explore the logic of forming the cohort effect of green governance and green development in China in the new era. Based on provincial panel data from 2008 to 2018, this paper examines the existence, scope, and induced control of the green governance peer effects using a spatial econometric approach. The study found that the following: (1) Influenced by the top-level design of the central government and the contradictory governance of regional development, the local governments form the peer effects in green governance activities. The existence of spatial relationships makes local governments dependent on a solid financial support system and a basis for industrial transformation, thus counteracting regional competition for green governance. (2) The green governance peer effects tend to decay with increasing geographical distance but do not disappear across regional boundaries under either spatial interaction framework. (3) Considering the impact of green governance policy systems and regional heterogeneity, the green governance peer effects decrease in the eastern, western, and central regions in that order. (4) Further, the influencing factors show that the green governance peer effects arise from intra-local government competition under the decentralization of power between the central and local governments. The competition for scales and the relative performance appraisal system reinforces the peer motivation of each subject. (5) The strong correlation of green governance willingness indicates that local governments cannot escape from will-led emotional behavior, and personal interests and governance motivation further drive the formation of pseudo-rational decisions, ultimately leading to irrational group decisions.

Gold Nanorods-Based Photothermal Therapy: Interactions Between Biostructure, Nanomaterial, and Near-Infrared Irradiation.

Gold nanorods (AuNRs) are ideal inorganic nanophotothermal agents with unique characteristics, including local surface plasmon resonance effects, easy scale preparation and functional modification, and good biocompatibility. This review summarizes several recent advances in AuNRs-based photothermal therapy (PTT) research. Functionalized AuNRs photothermal agents have optimized biocompatibility and targeting properties. The multifunctional AuNRs nanoplatform composite structure meets the requirements for synergistic effects of PTT, photoacoustic imaging, and other therapeutic methods. Photothermal therapy with AuNRs (AuNRs-PTT) is widely used to treat tumors and inflammatory diseases; its tumor-targeting, tumor metastasis inhibition, and photothermal tumor ablation abilities have remarkable curative effects. An in-depth study of AuNRs in living systems and the interactions between biological structure, nanomaterial, and near-infrared irradiation could lay the foundation for further clinical research and the broad application of AuNRs in PTT.

Development and validation of an ultrasound-based nomogram for preoperative prediction of cervical central lymph node metastasis in papillary thyroid carcinoma.

BACKGROUND: Preoperative prediction of central lymph node metastasis (CLNM) holds significant value in determining a patient's suitability for surgical resection and the need for adjuvant treatment, thereby contributing to better therapeutic strategies. This study aimed to build and confirm a nomogram that integrates ultrasound (US) characteristics with clinical features to predict CLNM in patients with papillary thyroid carcinoma (PTC) preoperatively. METHODS: The prediction model was set up with a training dataset that included 512 patients with histopathologically confirmed PTC. The least absolute shrinkage and selection operator (LASSO) regression method was applied to select US features in the development cohort. The patients' US characteristics and clinical features were incorporated into a multivariate logistic regression analysis to develop the nomogram. The clinical feasibility, calibration, and discriminatory ability of the nomogram were evaluated in an independent validation cohort of 306 patients. RESULTS: Age, sex, tumor size, multiple tumors, and US-based CLNM status were included as independent predictors in the personalized nomogram. The nomogram showed good calibration and discrimination in the training and validation datasets. The addition of the BRAF V600E mutation status did not improve the performance of the nomogram. The decision curve analysis showed the nomogram to have clinical feasibility. CONCLUSIONS: A nomogram that integrates US characteristics with patients' clinical features was built. This US-based nomogram can be expediently applied to promote the personalized preoperative prediction of CLNM and to develop surgical strategies, such as tailored central compartment neck dissection, in patients with PTC.

A retrospective analysis of kidney function and risk factors by Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation in elderly Chinese patients.

Chronic kidney disease accounts for much of the increased mortality, especially in the elder population. The prevalence of this disease is expected to increase significantly as the society ages. Our aim was to evaluate the kidney function and risk factors of reduced renal function among elderly Chinese patients. This study retrospectively collected clinical data from a total of 1062 inpatients aged 65 years or over. Estimated glomerular filtration rate (eGFR) was calculated with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Renal function and risk factors were also analyzed. For all 1062 subjects, the mean eGFR was 71.0 ± 24.8 mL/min/1.73 m(2), and the incidence rates of reduced renal function, proteinuria, hematuria and leukocyturia were 31.1%, 11.8%, 6.6% and 8.7%, respectively. The eGFR values were 83.4 ± 28.4, 72.2 ± 22.9, 67.8 ± 24.3 and 58.8 ± 29.1 mL/min/1.73 m(2) in the groups of 60-69, 70-79, 80-89 and ≥90 years age group (F = 15.101, p = 0.000), respectively; while the incidences of reduced renal function were 12.8%, 27.0%, 37.8% and 51.7% (χ(2) = 36.143, p = 0.000). Binary logistic regression analysis showed that hyperuricemia (OR = 4.62, p = 0.000), proteinuria (OR = 3.96, p = 0.000), urinary tumor (OR = 2.92, p = 0.015), anemia (OR = 2.45, p = 0.000), stroke (OR = 1.96, p = 0.000), hypertension (OR = 1.83, p = 0.006), renal cyst (OR = 1.64, p = 0.018), female (OR = 1.54, p = 0.015), coronary artery disease (OR = 1.53, p = 0.008) and age (OR = 1.05, p = 0.000) were the risk factors of reduced renal function. In conclusion, eGFR values decreased by age, while the incidence of reduced renal function, proteinuria, hematuria and leukocyturia increased with age. Treatment and control of comorbidities may slow the decline of renal function in elderly patients.

[Value of strain means of quantitative parameters in diagnosis of liver fibrosis].

OBJECTIVE: To explore the value of the strain means of the quantitative parameters of organization diffusion in determining the degree of liver fibrosis. METHODS: A total of 130 patients with chronic hepatitis B were examined for quantitative analysis of organization diffusion before liver biopsy to analyze the performance of the strain means in liver fibrosis of different degrees. All the cases were confirmed by pathology. RESULTS: The strain means differed significantly between different stages of liver fibrosis. Using the best cut-off values of 116.2, 111.4, 101.6 and 97.5 for diagnosis of S≥1, S≥2, S≥3 and S=4, the diagnostic sensitivities were 91.2%, 90.8%, 95.8% and 89.7%, with specificities of 90.4%, 98.6%, 93.8% and 95.6% and accuracies of 90.6%, 94.7%, 95.5% and 91.8%, respectively. CONCLUSION: The strain mean can provide specific numerical indicators to determine the degree of liver fibrosis.

[Age and prognosis: analysis of their association in 93 cases of cervical cancer].

OBJECTIVE: To investigate the relationship between the patient's age and clinical prognosis of cervical cancer. METHODS: Ninety-three patients with cervical cancer selected from those hospitalized in Nanfang Hospital from Jan 1997 to Dec 2002 were divided into younger age (less than 35 years old) and elder age group ( more than 35 years old). Comparison was made in the clinical stages, pathological grade and differentiation between the 2 groups. RESULTS: Statistical difference was found in the clinical stages and pathological grade between the 2 groups, and in patients below the age of 35 years, 82.61% were below stage II a and 17.39% above stage II b, had squamous cell carcinoma and 13.39% had adenocarcinoma; In those above 35 years, 51.43% were classified below stage II a stage and 48.73% above stage II b, and squamous cell carcinoma were identified in 82.98% and adenocarcinoma in 17.02% of these patients. However, no statistical difference was found in the cell differentiation between the two groups. CONCLUSIONS: Patients above 35 years have poorer prognosis than their younger counterparts, which might be due to more advanced clinical stage and higher rate of adenocarcinoma.