Emerging Artificial Neuron Devices for Probabilistic Computing.

In recent decades, artificial intelligence has been successively employed in the fields of finance, commerce, and other industries. However, imitating high-level brain functions, such as imagination and inference, pose several challenges as they are relevant to a particular type of noise in a biological neuron network. Probabilistic computing algorithms based on restricted Boltzmann machine and Bayesian inference that use silicon electronics have progressed significantly in terms of mimicking probabilistic inference. However, the quasi-random noise generated from additional circuits or algorithms presents a major challenge for silicon electronics to realize the true stochasticity of biological neuron systems. Artificial neurons based on emerging devices, such as memristors and ferroelectric field-effect transistors with inherent stochasticity can produce uncertain non-linear output spikes, which may be the key to make machine learning closer to the human brain. In this article, we present a comprehensive review of the recent advances in the emerging stochastic artificial neurons (SANs) in terms of probabilistic computing. We briefly introduce the biological neurons, neuron models, and silicon neurons before presenting the detailed working mechanisms of various SANs. Finally, the merits and demerits of silicon-based and emerging neurons are discussed, and the outlook for SANs is presented.

Spectroscopy, Thermodynamics and Molecular Docking of Fraxinellone with DNA.

Fraxinellone is an important botanical lactone compound and has been demonstrated to have insecticidal activity. To provide theoretical support to the assessment on the safety of utilizing fraxinellone as a natural insecticidal agent, the interactions between fraxinellone and armyworm DNA, salmon sperm DNA and calf thymus DNA were investigated using UV-Vis absorption spectroscopy, isothermal titration calorimetry, and molecular docking. Results showed that there were two types of combinations between fraxinellone and three kinds of DNA. Type I combination had an equilibrium constant of combination (Ka1) of about 105 and binding sites (n1) of 0.40-0.70, while type II combination had an equilibrium constant of combination (Ka2) of 103 and binding sites (n2) of 1.35-3.15. Results of molecular docking showed that there were non-classical embedding type interactions between fraxinellone and three kinds of DNA, with the reaction taking place in small groove areas of the DNA structure, resulting in relatively weak interactive forces.

Configurable multi-state non-volatile memory behaviors in Ti3C2 nanosheets.

MXenes have drawn considerable attention in both academia and industry due to their attractive properties, such as a combination of metallic conductivity and surface hydrophilicity. However, to the best of our knowledge, the potential use of MXenes in non-volatile resistive random access memories (RRAMs) has rarely been reported. In this paper, we first demonstrated a RRAM device with MXene (Ti3C2) as the active component. The Ti3C2-based RRAM exhibited typical bipolar switching behavior, long retention characteristics, low SET voltage, good mechanical stability and excellent reliability. By adjusting different compliance currents in the SET process, multi-state information storage was achieved. The charge trapping assisting hopping process is considered to be the main mechanism of resistive switching for this fabricated Ti3C2-based RRAM, which was verified by conductive atomic force microscopy (C-AFM) and Kelvin probe force microscopy (KPFM). Moreover, this flexible Ti3C2-based RRAM, with good mechanical stability and long retention properties, was successfully fabricated on a plastic substrate. Ti3C2-based RRAMs may open the door to additional applications and functionalities, with high potential for application in flexible electronics.

Near-Infrared Annihilation of Conductive Filaments in Quasiplane MoSe2 /Bi2 Se3 Nanosheets for Mimicking Heterosynaptic Plasticity.

It is desirable to imitate synaptic functionality to break through the memory wall in traditional von Neumann architecture. Modulating heterosynaptic plasticity between pre- and postneurons by another modulatory interneuron ensures the computing system to display more complicated functions. Optoelectronic devices facilitate the inspiration for high-performance artificial heterosynaptic systems. Nevertheless, the utilization of near-infrared (NIR) irradiation to act as a modulatory terminal for heterosynaptic plasticity emulation has not yet been realized. Here, an NIR resistive random access memory (RRAM) is reported, based on quasiplane MoSe2 /Bi2 Se3 heterostructure in which the anomalous NIR threshold switching and NIR reset operation are realized. Furthermore, it is shown that such an NIR irradiation can be employed as a modulatory terminal to emulate heterosynaptic plasticity. The reconfigurable 2D image recognition is also demonstrated by an RRAM crossbar array. NIR annihilation effect in quasiplane MoSe2 /Bi2 Se3 nanosheets may open a path toward optical-modulated in-memory computing and artificial retinal prostheses.

Infrared-Sensitive Memory Based on Direct-Grown MoS2 -Upconversion-Nanoparticle Heterostructure.

Photonic memories as an emerging optoelectronic technology have attracted tremendous attention in the past few years due to their great potential to overcome the von Neumann bottleneck and to improve the performance of serial computers. Nowadays, the decryption technology for visible light is mature in photonic memories. Nevertheless, near-infrared (NIR) photonic memristors are less progressed. Herein, an NIR photonic memristor based on MoS2 -NaYF4 :Yb3+ , Er3+ upconversion nanoparticles (UCNPs) nanocomposites is designed. Under excitation by 980 nm NIR light, the UCNPs show emissions well overlapping with the absorption band of the MoS2 nanosheets. The heterostructure between the MoS2 and the UCNPs acting as excitons generation/separation centers remarkably improves the NIR-light-controlled memristor performance. Furthermore, in situ conductive atomic force microscopy is employed to elucidate the photo-modulated memristor mechanism. This work provides novel opportunities for NIR photonic memory that holds promise in future multifunctional robotics and electronic eyes.

[Value of indoleamine 2,3-dioxygenase in diagnosis of systemic inflammatory response syndrome after cardiopulmonary bypass in children with congenital heart disease].

OBJECTIVE: To study the value of indoleamine 2,3-dioxygenase (IDO) in the early diagnosis of systemic inflammatory response syndrome (SIRS) after cardiopulmonary bypass in children with congenital heart disease. METHODS: A total of 90 children with congenital heart disease who underwent cardiopumonary bypass surgery between May 2012 and January 2016 were enrolled. According to the prsence or absence of SIRS after surgery, they were divided into SIRS group (n=43) and control group (n=47). Peripheral blood samples were collected before surgery, during surgery, and after surgery. Serum levels of IDO, C-reactive protein (CRP), and interleukin-6 (IL-6) were measured and compared between the two groups. The receiver operating characteristic (ROC) curve was used to evaluate their diagnostic efficiency. RESULTS: Compared with the control group, the SIRS group had higher serum CRP levels at 72 hours after surgery, higher IL-6 levels during surgery and at 72 hours after surgery, and higher IDO levels at 24 and 72 hours after surgery. IDO had a certain value in the diagnosis of SIRS at 24 hours after surgery with an area under the ROC curve (AUC) of 0.793, a specificity of 100%, and a sensitivity of 58.14%. CRP, IL-6, and IDO had a certain value in the diagnosis of SIRS at 72 hours after surgery. IDO had the highest diagnostic efficiency with an AUC of 0.927, a specificity of 95.74%, and a sensitivity of 76.74% at 72 hours after surgery. CONCLUSIONS: IL-6, CRP, and IDO have a certain value in the diagnosis of SIRS after surgery for congenital heart disease, and IDO has a higher diagnostic efficiency. IDO can predict the development of SIRS in children after surgery for congenital heart disease earlier.

[Diagnostic significance of urinary neutrophil gelatin enzyme-related lipid delivery protein and kidney injury molecule-1 in acute kidney injury after cardiac operation with cardiopulmonary bypass operation in children].

OBJECTIVE: To investigate the diagnostic value of urinary neutrophil gelatin enzyme-related lipid delivery protein (NGAL) and kidney injury molecule-1 (KIM-1) in the acute kidney injury (AKI) after cardiopulmonary bypass (CPB) operation in children with non-cyanotic congenital heart disease (CHD). METHODS: A retrospective analysis was conducted. 200 CPB undergoing cardiac surgery in children with non-cyanotic CHD admitted to Tianjin Children's Hospital from June 2015 to May 2017 were enrolled. All patients were divided into AKI group and non-AKI group within 48 hours after operation, and the two groups matched with age, sex, weight, basic complications, operation time and other factors. The differences in serum creatinine (SCr), urinary NGAL and KIM-1 [corrected for urinary creatinine (UCr)] between the two groups before and after operation were compared. The early diagnosis value of urinary NGAL and KIM-1 on AKI was analyzed by the receiver operating characteristic curve (ROC). RESULTS: There were 32 patients with different degrees of AKI 48 hours post operation, and the incidence was 16.0%; 60 cases were enrolled in non-AKI group. Compared with non-AKI group, urinary NGAL at 2 hours after operation, urine KIM-1 at 4 hours after operation, and SCr at 10 hours after operation in AKI group were significantly increased, which decreased gradually after reaching peak at 6, 8, 24 hours respectively. It was shown by ROC curve analysis that the area under ROC curve (AUC) and 95% confidence interval (95%CI) of postoperative 2-hour urine NGAL, 4-hour urine KIM-1 and 10-hour SCr for diagnosis of AKI were 0.940 (95%CI = 0.890-0.990), 0.939 (95%CI = 0.891-0.986) and 0.959 (95%CI = 0.916-1.000) respectively. When the cut-off value of postoperative 2-hour urine NGAL was 588.0 µg/g, the sensitivity was 87.5%, the specificity was 95.0%, the accuracy was 93.5%; when the cut-off value of postoperative 4-hour urine KIM-1 was 9.55 ng/mg, the sensitivity was 87.5%, the specificity was 91.7%, the accuracy was 90.2%; and when the cut-off value of postoperative 10-hour SCr was 61.90 µmol/L, the sensitivity was 90.6%, the specificity was 95.0%, and the accuracy was 95.7%. CONCLUSIONS: Urine NGAL and KIM-1 can be used as biomarkers for early diagnosis of AKI after CPB for the non-cyanotic CHD in children.

Coexistence of multiple coronaviruses in several bat colonies in an abandoned mineshaft.

Since the 2002-2003 severe acute respiratory syndrome (SARS) outbreak prompted a search for the natural reservoir of the SARS coronavirus, numerous alpha- and betacoronaviruses have been discovered in bats around the world. Bats are likely the natural reservoir of alpha- and betacoronaviruses, and due to the rich diversity and global distribution of bats, the number of bat coronaviruses will likely increase. We conducted a surveillance of coronaviruses in bats in an abandoned mineshaft in Mojiang County, Yunnan Province, China, from 2012-2013. Six bat species were frequently detected in the cave: Rhinolophus sinicus, Rhinolophus affinis, Hipposideros pomona, Miniopterus schreibersii, Miniopterus fuliginosus, and Miniopterus fuscus. By sequencing PCR products of the coronavirus RNA-dependent RNA polymerase gene (RdRp), we found a high frequency of infection by a diverse group of coronaviruses in different bat species in the mineshaft. Sequenced partial RdRp fragments had 80%-99% nucleic acid sequence identity with well-characterized Alphacoronavirus species, including BtCoV HKU2, BtCoV HKU8, and BtCoV1, and unassigned species BtCoV HKU7 and BtCoV HKU10. Additionally, the surveillance identified two unclassified betacoronaviruses, one new strain of SARS-like coronavirus, and one potentially new betacoronavirus species. Furthermore, coronavirus co-infection was detected in all six bat species, a phenomenon that fosters recombination and promotes the emergence of novel virus strains. Our findings highlight the importance of bats as natural reservoirs of coronaviruses and the potentially zoonotic source of viral pathogens.

Temperature-Dependent Photoluminescence Property of Self-Assembly ZnO Nanowires via Chemical Vapor Deposition Combined with Hydrothermal Pretreatment.

Vertically aligned ZnO nanowires with high aspect ratio were prepared by chemical vapor deposition on Si substrate, which had been catalyzed by the polar plane in [0001] direction of ZnO nanorods prepared by the hydrothermal method. Morphology and structure characterizations showed that the as-grown nanowires had the single-crystal hexagonal wurtzite structure with a [0001] growth direction. Energy Dispersive X-ray (EDX) measurement indicated the as-grown ZnO nanowires had a good deal of oxygen vacancies owing to the high operation temperature. Temperature-dependent photoluminescence measurement revealed that the peak of near-band-edge emission shifted from 380 to 387 nm with the increase of temperature from 150 to 300 K. The high intensity of the green peak at 525 nm highlighted the potential application in visible light emitting diodes.

Surgical treatment of tricuspid regurgitation after mitral valve surgery: a retrospective study in China.

BACKGROUND: Functional tricuspid regurgitation (TR) occurs in patients with rheumatic mitral valve disease even after mitral valve surgery. The aim of this study was to analyze surgical results of TR after previous successful mitral valve surgery. METHODS: From September 1996 to September 2008, 45 patients with TR after previous mitral valve replacement underwent second operation for TR. In those, 43 patients (95.6%) had right heart failure symptoms (edema of lower extremities, ascites, hepatic congestion, etc.) and 40 patients (88.9%) had atrial fibrillation. Twenty-six patients (57.8%) were in New York Heart Association (NYHA) functional class III, and 19 (42.2%) in class IV. Previous operations included: 41 for mechanical mitral valve replacement (91.1%), 4 for bioprosthetic mitral valve replacement (8.9%), and 7 for tricuspid annuloplasty (15.6%). RESULTS: The tricuspid valves were repaired with Kay's (7 cases, 15.6%) or De Vega technique (4 cases, 8.9%). Tricuspid valve replacement was performed in 34 cases (75.6%). One patient (2.2%) died. Postoperative low cardiac output (LCO) occurred in 5 patients and treated successfully. Postoperative echocardiography showed obvious reduction of right atrium and ventricle. The anterioposterior diameter of the right ventricle decreased to 25.5 ± 7.1 mm from 33.7 ± 6.2 mm preoperatively (P < 0. 05). CONCLUSION: TR after mitral valve replacement in rheumatic heart disease is a serious clinical problem. If it occurs or progresses late after mitral valve surgery, tricuspid valve annuloplasty or replacement may be performed with satisfactory results. Due to the serious consequence of untreated TR, aggressive treatment of existing TR during mitral valve surgery is recommended.

The current strategy of repair of tetralogy of Fallot in children and adults.

OBJECTIVES: The strategies of repair of tetralogy of Fallot change with the age of patients. In children older than 4 years and adults, the optimal strategy may be to use different method of reconstruction of the right ventricular outflow tract from those followed in younger children, so as to avoid, or reduce, the pulmonary insufficiency that is increasingly known to compromise right ventricular function. METHODS: From April, 2001, through May, 2008, we undertook complete repair in 312 patients, 180 male and 132 female, with a mean age of 11.3 years +/-0.4 years, and a range from 4 to 48 years, with typical clinical and morphological features of tetralogy of Fallot, including 42 patients with the ventriculo-arterial connection of double outlet right ventricle. The operation was performed under moderate hypothermia using blood cardioplegia. The ventricular septal defect was closed with a Dacron patch. When it was considered necessary to resect the musculature within the right ventricular outflow tract, or perform pulmonary valvotomy, we sought to preserve the function of the pulmonary valve by protecting as far as possible the native leaflets, or creating a folded monocusp of autologous pericardium. RESULTS: The repair was achieved completely through right atrium in 192, through the right ventricular outflow tract in 83, and through the right atrium, the outflow tract, and the pulmonary trunk in 36 patients. A transjunctional patch was inserted in 169 patients, non-valved in all but 9. There were no differences regarding the periods of aortic cross-clamping or cardiopulmonary bypass. Of the patients, 5 died (1.6%), with no influence noted for the transjunctional patch. Of those having a non-valved patch inserted, three-tenths had pulmonary regurgitation of various degree, while those having a valved patch had minimal pulmonary insufficiency and good right ventricular function postoperatively, this being maintained after follow-up of 8 to 24-months. CONCLUSIONS: Based on our experience, we suggest that the current strategy of repair of tetralogy of Fallot in older children and adults should be based on minimizing the insertion of transjunctional patches, this being indicated only in those with very small ventriculo-pulmonary junctions. If such a patch is necessary, then steps should be taken to preserve the function of the pulmonary valve.

2-Benzyl-imino-methyl-4-chloro-phenol.

The title compound, C(14)H(12)ClNO, is a Schiff base derived from the condensation of equimolar quanti-ties of 5-chloro-salicylaldehyde and 1-benzyl-amine. The mol-ecule has a trans configuration with respect to the imine C=N double bond. The N atom is involved in an intra-molecular O-H⋯N hydrogen bond.

(E)-4-[(2-Hydroxy-benzyl-idene)amino]benzene-sulfonic acid.

The title mol-ecule, C(13)H(11)NO(4)S, displays a trans configuration with respect to the imine C=N double bond. The central benzene ring directly linked to N and the hydroxyl group are disordered over two orientations [occupancies of 0.510 (16)/0.490 (16) and 0.528 (8)/0.472 (8), respectively]. The dihedral angle between the two aromatic rings is 23.3 (5)° for the major component and 18.3 (5)° for the minor component. There is an intra-molecular O-H⋯N hydrogen bond and mol-ecules are linked into chains along the a axis by O-H⋯O hydrogen bonds.

A novel fluorogenic coumarin substrate for monitoring acid phosphatase activity at low pH environment.

This article described the synthesis and application of 6-chloro-8-fluoro-4-methylumbelliferone phosphate (CF-MUP) in analyzing acid phosphatase activity. Compared to the existing MUP, the new coumarin phosphate, CF-MUP, demonstrateed much higher sensitivity and was more robust for detecting the activity of acid phosphatase than the classic substrate 4-methylumbelliferone phosphate (MUP). The product of enzyme reaction, 6-chloro-8-fluoro-4-methylumbelliferone (CF-MU) possesses strong fluorescence at approximately 450 nm with low pKa (4.7), high fluorescence quantum yield and pH independence in the physiological pH range. This new fluorescence dye, CF-MU, is a convenient tool for assays with buffer pH between 4.5 and 8.

8-demethoxyrunanine from Sinomenium acutum.

A new hasubanane-type alkaloid, named 8-demethoxyrunanine, was isolated from the rhizome of Sinomenium acutum. Its structure was determined by spectroscopic methods and X-ray diffraction analysis.

Bis[2-(benzyl-imino-meth-yl)-4-chloro-phenolato-κN,O]nickel(II).

In the mononuclear centrosymmetric title compound, [Ni(C(14)H(11)ClNO)(2)], the Ni(II) atom, lying on a center of symmetry, is four-coordinated by two O atoms and two N atoms from two Schiff base ligands, forming a slightly distorted square-planar environment. The dihedral angle between the two aromatic rings of the ligand is 72.0 (2)°. No significant hydrogen bonding or π-π stacking inter-actions are observed.

Bis(4-chloro-2-formyl-phenolato)nickel(II).

The asymmetric unit of the title compound, [Ni(C(7)H(4)ClO(2))(2)], contains one half-mol-ecule. The Ni(II) ion, lying on an inversion centre, is four-coordinated by O atoms of 5-chloro-salicylaldehydate ligands in a square-planar geometry.

Bis[µ-2-(benzyl-imino-meth-yl)-4-chloro-phenolato]bis[chloridocopper(II)].

The title complex, [Cu(2)(C(14)H(11)ClNO)(2)Cl(2)], has a centrosymmetric dinuclear structure where two symmetry-related copper(II) metal centres are bridged by the O atoms of two phen-oxy groups. Each copper(II) centre displays a distorted tetra-hedral coordination provided by one N atom and two O atoms from two Schiff base ligands and by one Cl atom. The Cu⋯Cu separation is 3.0702 (9) Å.

Trans-2,2',4,4'-tetramethyl-6,6'-dinitroazobenzene from Aconitum sungpanense.

Trans-2,2',4,4'-tetramethyl-6,6'-dinitroazobenzene from the leaves of Aconitum sungpanense was reported as a new compound. The structure was determined by spectroscopic methods and X-ray diffraction analysis.