Novel Semiconductive Ternary Hybrid Heterostructures for Artificial Optoelectronic Synapses.

Synaptic devices that mimic biological synapses are considered as promising candidates for brain-inspired devices, offering the functionalities in neuromorphic computing. However, modulation of emerging optoelectronic synaptic devices has rarely been reported. Herein, a semiconductive ternary hybrid heterostructure is prepared with a D-D'-A configuration by introducing polyoxometalate (POM) as an additional electroactive donor (D') into a metalloviologen-based D-A framework. The obtained material features an unprecedented porous 8-connected bcu-net that accommodates nanoscale [α-SiW12 O40 ]4- counterions, displaying uncommon optoelectronic responses. Besides, the fabricated synaptic device based on this material can achieve dual-modulation of synaptic plasticity due to the synergetic effect of electron reservoir POM and photoinduced electron transfer. And it can successfully simulate learning and memory processes similar to those in biological systems. The result provides a facile and effective strategy to customize multi-modality artificial synapses in the field of crystal engineering, which opens a new direction for developing high-performance neuromorphic devices.

Donor-Acceptor Hybrid Heterostructures: An Emerging Class of Photoactive Materials with Inorganic and Organic Semiconductive Components.

Just as the heterojunctions in physics, donor-acceptor (D-A) heterostructures are an emerging class of photoactive materials fabricated from two semiconductive components at the molecular level. Among them, D-A hybrid heterostructures from organic and inorganic semiconductive components have attracted extensive attention in the past decades due to their combined advantages of high stability for the inorganic semiconductors and modifiability for the organic semiconductors, which are particularly beneficial to efficiently achieve photoinduced charge separation and transfer upon irradiations. In this review, by analogy with the heterojunctions in physics, a definition of the D-A heterostructures and their general design and synthetic strategies are given. Meanwhile, the D-A hybrid heterostructures are focused on and their recent advances in potential applications of photochromism, photomodulated luminescence, and photocatalysis summarized.

Molecular Dynamics, Phase Transition and Frequency-Tuned Dielectric Switch of an Ionic Co-Crystal.

Dielectric switches that can be converted between high and low dielectric states by thermal stimuli have attracted much interest owing to their many potential applications. Currently one main drawback for practical application lies in the non-tunability of their switch temperatures (TS ). We report here an ionic co-crystal (Me3 NH)4 [Ni(NCS)6 ] that contains a multiply rotatable Me3 NH+ ion and a solely rotatable one due to a more spacious supramolecular cage for the former one. This compound undergoes an isostructural order-disorder phase transition and it can function as a frequency-tuned dielectric switch with highly adjustable TS , which is further revealed by the variable-temperature structure analyses and molecular dynamics simulations. In addition, the distinct arrangements and molecular dynamics of two coexisting Me3 NH+ ions confined in different lattice spaces as well as the notable offset effect on the promoting/hindering of dipolar reorientation after dielectric transition provide a rarely observed but fairly good model for understanding and modulating the dipole motion in crystalline environment.

Tissue distribution and excretion study of neopanaxadiol in rats by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry.

Neopanaxadiol (NPD), a major ginsenoside in Panax ginseng C. A. Meyer (Araliaceae), was reported to have neuroprotective effect. In this study, a method of ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC/QTOF-MS) was developed and validated for quantitative analysis of NPD in tissues, urine and feces, using liquid-liquid extraction (LLE) to isolate NPD from different biological samples, and chromatographic separation was performed on an Agilent Zorbax Stable Bond C18 (2.1 × 50 mm, 1.8 µm) column with 0.1% formic acid in water and acetonitrile. All standard calibration curves were linear (all r(2) > 0.995) within the test range. After oral administration, NPD was extensively distributed to most of the tissues without long-term accumulation. The higher levels were observed in stomach and intestine, followed by kidney and liver. Approximately 64.56 ± 20.32% of administered dose in feces and 0.0233 ± 0.0356% in urine were found within 96 h, which indicated that the major elimination route was fecal excretion. This analytical method was applied to the study of NPD distribution and excretion in rats after oral intake for the first time. The results we found here are helpful for us to understand the pharmacological effects of NPD, as well as its toxicity.

[Preparation and Determination of Insulin-like Growth Factor I in Deer Antler, Heart and Blood].

OBJECTIVE: To optimize the method for preparation of the insulin-like growth factor I (IGF-I ) in deer antler, and to determine the IGF-I in deer antler, heart and blood. METHODS: Ultrasonic extraction was used to extract IGF-I from different tissues of deer with ammonia-ammonium acetate buffer, followed by ultrafiltration and solid phase extraction to concentrate and purify the samples. At the same time, ethanol precipitation method was carried out in the purification of IGF-I ultrafiltratein deer antler, a parallel test proceeded and radio immune assay (RIA) was set to determine the IGF-I in deer antler, heart and blood. RESULTS: The IGF-I (60.8 ng/g) in deer antler by solid phase extraction was only existed in 30% methanol aqueous solution which was much higher than that (46.1 ng/g) by ethanol precipitation method. The quantities of IGF-I in deer antler, heart and blood were significantly different, it was 61.9 ng/g in antler and 21.9 ng/mL in blood, while there was no IGF-I tested in deer heart. CONCLUSION: Solid phase extraction is superior to ethanol precipitation method in preparing IGF-I in deer antler and it is clear that the IGF-I contained in deer antler is significantly higher than that in deer heart and blood, so it is the best choice to take IGF-I from deer antler.

Deep learning-assisted ultrasonic diagnosis of cervical lymph node metastasis of thyroid cancer: a retrospective study of 3059 patients.

Objective: This study aimed to develop a deep learning system to identify and differentiate the metastatic cervical lymph nodes (CLNs) of thyroid cancer. Methods: From January 2014 to December 2020, 3059 consecutive patients with suspected with metastatic CLNs of thyroid cancer were retrospectively enrolled in this study. All CLNs were confirmed by fine needle aspiration. The patients were randomly divided into the training (1228 benign and 1284 metastatic CLNs) and test (307 benign and 240 metastatic CLNs) groups. Grayscale ultrasonic images were used to develop and test the performance of the Y-Net deep learning model. We used the Y-Net network model to segment and differentiate the lymph nodes. The Dice coefficient was used to evaluate the segmentation efficiency. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were used to evaluate the classification efficiency. Results: In the test set, the median Dice coefficient was 0.832. The sensitivity, specificity, accuracy, PPV, and NPV were 57.25%, 87.08%, 72.03%, 81.87%, and 66.67%, respectively. We also used the Y-Net classified branch to evaluate the classification efficiency of the LNs ultrasonic images. The classification branch model had sensitivity, specificity, accuracy, PPV, and NPV of 84.78%, 80.23%, 82.45%, 79.35%, and 85.61%, respectively. For the original ultrasonic reports, the sensitivity, specificity, accuracy, PPV, and NPV were 95.14%, 34.3%, 64.66%, 59.02%, 87.71%, respectively. The Y-Net model yielded better accuracy than the original ultrasonic reports. Conclusion: The Y-Net model can be useful in assisting sonographers to improve the accuracy of the classification of ultrasound images of metastatic CLNs.

Differential Diagnosis of DCIS and Fibroadenoma Based on Ultrasound Images: a Difference-Based Self-Supervised Approach.

Differentiation of ductal carcinoma in situ (DCIS, a precancerous lesion of the breast) from fibroadenoma (FA) using ultrasonography is significant for the early prevention of malignant breast tumors. Radiomics-based artificial intelligence (AI) can provide additional diagnostic information but usually requires extensive labeling efforts by clinicians with specialized knowledge. This study aims to investigate the feasibility of differentially diagnosing DCIS and FA using ultrasound radiomics-based AI techniques and further explore a novel approach that can reduce labeling efforts without sacrificing diagnostic performance. We included 461 DCIS and 651 FA patients, of whom 139 DCIS and 181 FA patients constituted a prospective test cohort. First, various feature engineering-based machine learning (FEML) and deep learning (DL) approaches were developed. Then, we designed a difference-based self-supervised (DSS) learning approach that only required FA samples to participate in training. The DSS approach consists of three steps: (1) pretraining a Bootstrap Your Own Latent (BYOL) model using FA images, (2) reconstructing images using the encoder and decoder of the pretrained model, and (3) distinguishing DCIS from FA based on the differences between the original and reconstructed images. The experimental results showed that the trained FEML and DL models achieved the highest AUC of 0.7935 (95% confidence interval, 0.7900-0.7969) on the prospective test cohort, indicating that the developed models are effective for assisting in differentiating DCIS from FA based on ultrasound images. Furthermore, the DSS model achieved an AUC of 0.8172 (95% confidence interval, 0.8124-0.8219), indicating that our model outperforms the conventional radiomics-based AI models and is more competitive.

[Influence factors for prognosis in patients with acute oral poisoning with paraquat].

OBJECTIVE: To investigate the influential factors for the prognosis in patients with paraquat poisoning. METHODS: Retrospective analysis was performed on 40 patients with acute paraquat poisoning to evaluate serum urea nitrogen, creatinine, alanine aminotransferase, and aspartate aminotransferase levels and organ injuries. RESULTS: Among the patients, 21 had lung injury, 26 had kidney injury, 13 had multiple organ dysfunction syndrome, and 12 died. The factors associated with lung injury were kidney injury and serum urea nitrogen and creatinine levels within 24 hours after paraquat poisoning. CONCLUSION: The renal function in early stage of paraquat poisoning is related to lung injury and thus can be used asa predictor for the incidence of lung injury.

Impact of diffusion methods and metal cations on photochromic three-component D-A hybrid heterostructures.

D-A hybrid heterostructures are an attractive class of hybrid complexes composed of semiconducting organic and inorganic components, which make them potential candidates for applications in the photoelectric fields, particularly as photochromic materials. Herein, we report that the combination of metal cations (M = Zn2+ or Cd2+), silicomolybdic anions, and N,N-di(4-pyridyl)-1,4,5,8-naphthalene diimide (DPNDI) via two diffusion methods (A and B) led to four three-component D-A hybrid heterostructures with silicomolybdic anions as electron donors, and one-dimensional (1-D) naphthalenediimide coordination networks of different metal cations, [Zn2(DPNDI)2(H2O)4]·(SiMo12O40) (1-A and 1-B) and [Cd2(DPNDI)2(H2O)4]·(SiMo12O40) (2-A and 2-B), as electron acceptors. Although the different diffusion methods, 1-B, 2-A and 2-B, are isostructures with close cell parameters. Due to the different ionic radii and electronegativity of metal cations in isostructural 1-B and 2-B, they exhibit different electron-transfer photochromic behaviors. This study paves a new path for designing novel photochromic materials through such third-component metal cations.

Partially cystic thyroid cancer on conventional and elastographic ultrasound: a retrospective study and a machine learning-assisted system.

BACKGROUND: Thyroid carcinoma constitutes the vast majority of all thyroid cancer, most of which is the solid nodule type. No previous studies have examined combining both conventional and elastic sonography to evaluate the diagnostic performance of partially cystic thyroid cancer (PCTC). This retrospective study was designed to evaluate differentiation of PCTC from benign partially cystic nodules with a machine learning-assisted system based on ultrasound (US) and elastography. METHODS: Patients with suspicious partially cystic nodules and finally confirmed were included in the study. We performed conventional US and real-time elastography (RTE). The US features of nodules were recorded. The data set was entered into 6 machine-learning algorithms. Sensitivity, specificity, accuracy, and area under the curve (AUC) were calculated. RESULTS: A total of 177 nodules were included in this study. Among these nodules, 81 were malignant and 96 were benign. Wreath-shaped feature, micro-calcification, and strain ratio (SR) value were the most important imaging features in differential diagnosis. The random forest classifier was the best diagnostic model. CONCLUSIONS: US features of PCTC exhibited unique characteristics. Wreath-shaped partially cystic nodules, especially with the appearance of micro-calcifications and larger SR value, are more likely to be malignant. The random forest classifier might be useful to diagnose PCTC.

[The regulatory mechanism of Raf/MEK/ERK pathway on the rat cardiac hypertrophy induced by transverse aortic constriction].

OBJECTIVE: To investigate the mRNA, protein expression levels and the phosphorylation levels of key factors in rapidly accelerated fibrosarcoma/mitogen-activated protein kinase kinase/extracellular regulated protein kinases (Raf/MEK/ERK) pathway, and to clarify the regulatory function of Raf/MEK/ERK pathway in myocardial hypertrophy. METHODS: Twenty SD rats were divided into sham-operated group and model group. The myocardial hypertrophy model was established by transverse aortic constriction (TAC). At 12 weeks after TAC, blood samples were collected from the submandibular vein, and the serum was separated to detect the content of N terminal pro B type natriuretic peptide (NT-proBNP). After that, the rats were subjected to echocardiography and hemodynamic measurement. Then the pathological changes of myocardial tissue were observed. And the levels of mRNA, protein expression and the phosphorylation of key factors in Raf/MEK/ERK pathway were detected in myocardial tissue. RESULTS: Compared with sham-operated group, left ventricular end-diastolic interventricular septal thickness (IVSd), left ventricular end-systolic interventricular septal thickness (IVSs), left ventricular end-diastolic posterior wall thickness (LVPWd) and left vebtricular end-systolic posterior wall thickness (LVPWs) in TAC model group were increased significantly (P＜0.05,P＜0.01), left ventricular end-systolic diameter (LVIDs) was decreased significantly (P＜0.01), LV Mass and LW(LV Mass/Weight)were increased significantly (P＜0.05, P＜0.01). The levels of heart rate (HR), left ventricular pressure maximal rate of rise (+dp/dtmax), left ventricular pressure maximal rate of fall (-dp/dtmax) were decreased significantly (P＜0.01). The serum level of NT-proBNP in TAC rat was increased significantly (P＜0.01). The myocardial cells in TAC model group were arranged disorderly, myocardial cell hypertrophy, cytoplasm were increased significantly, and inflammatory cells infiltrated. A large amount of collagen fibers were deposited and large area of myocardial cells were stained blue in TAC rat. The expression levels of phospho-c-Raf (Ser259) and phospho-c-Raf (Ser338) in myocardial tissue were significantly increased (P＜0.01), meanwhile the expression levels of phospho- MEK1/2(Ser217/Ser221) and phospho-ERK1/2 (Thr202/Tyr204) were also significantly increased (P＜0.01). CONCLUSION: The regulatory role of Raf / MEK / ERK pathway in cardiac hypertrophy may be through the activation of phosphorylation of c-raf, MEK1, Mek2, ERK1 and ERK2 at specific sites.

Theoretical study on the reaction of SiH(CH(3))(3) with SiH(3) radical.

The multiple-channel reactions SiH(3) + SiH(CH(3))(3) --> products are investigated by direct dynamics method. The minimum energy path (MEP) is calculated at the MP2/6-31+G(d,p) level, and energetic information is further refined by the MC-QCISD (single-point) method. The rate constants for individual reaction channels are calculated by the improved canonical variational transition state theory with small-curvature tunneling correction over the temperature range of 200-2400 K. The theoretical three-parameter expression k(T) = 2.44 x 10(-23)T(3.94) exp(-4309.55/T) cm(3)/(molecule s) is given. Our calculations indicate that hydrogen abstraction channel R1 from SiH group is the major channel because of the smaller barrier height among five channels considered.

[Applied study on clustering of variables around latent components method in wavelength region selection with near-infrared spectroscopy].

The present paper introduced the principle of clustering of variables around latent components method, and used this method in selecting spectrum range of the NIR quantitative analysis models. Taking tobacco samples as experiment materials, we dealed with 107 sample spectra, divided the spectra into 5 clusters, and explained the information reflected by each of these 5 clusters in terms of chemistry. On this basis, we chose the corresponding wavelength range to set up the quantitative models of the total sugar, reducing sugar and nicotine by PLS method. Compared with the model based on the full NIR spectral range, Rtraining of the models based on the chosen spectral range rose from 0.977 1, 0.917 2 and 0.987 4 to 0.995 5, 0.975 1 and 0.994 4; Rtest rose from 0.977 8, 0.941 2 and 0.993 2 to 0.992 7, 0.967 9 and 0.994 0; RMSECV dropped from 1.09, 1.43, 0.14 to 1.05, 1.05 and 0.13, RMSEP dropped from 0.92, 1.17 and 0.16 to 0.39, 0.63 and 0.11 and the D value dropped from 1.274%, 1.972% and 0.829% to 0.711%, 0.843% and 0.768% for the total sugar, reducing sugar and nicotine, respectively. These data indicated that this method can improve the forecasting precision and stability of the model, so offers certain guidance on practical application.

Determination of noradrenaline and dopamine in Chinese herbal extracts from Portulaca oleracea L. by high-performance liquid chromatography.

A simple, rapid and accurate high-performance liquid chromatographic (HPLC) technique coupled with photodiode array (PDA) detection was developed for the simultaneous determination of noradrenaline (NA) and dopamine (DA) in Chinese herbal plant extracts from the different parts of Portulaca oleracea L. The effects of various parameters, such as sodium dodecyl sulfate (SDS) concentration, pH value and proportion of methanol on chromatographic behavior of the analytes (NA and DA) were investigated. Separation of NA and DA was achieved within 10 min by a mobile phase consisting of 70% (v/v) methanol and 0.02 M potassium dihydrogen phosphate solution, which contained 30 mM SDS and was adjusted to pH 3.0 with H3PO4. NA and DA showed good linear relationships in the range of 0.004-6.00 microg and 0.011-8.25 microg respectively. The correlation coefficients of the calibration curve for the analytes exceeded 0.999. The detection limits for NA and DA were 0.40 ng and 0.55 ng, at a signal-to-noise ratio of 3, respectively. Moreover, the optimized HPLC method was employed to analyze three different parts of Portulaca oleracea L.