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Brain-like energy-efficient computing has remained elusive for neuromorphic (NM) circuits and hardware platform implementations despite decades of research. In this work we reveal the opportunity to significantly improve the energy efficiency of digital neuromorphic hardware by introducing NM circuits employing two-dimensional (2D) transition metal dichalcogenide (TMD) layered channel material-based tunnel-field-effect transistors (TFETs). Our novel leaky-integrate-fire (LIF) based digital NM circuit along with its Hebbian learning circuitry operates at a wide range of supply voltages, frequencies, and activity factors, enabling two orders of magnitude higher energy-efficient computing that is difficult to achieve with conventional material and/or device platforms, specifically the silicon-based 7 nm low-standby-power FinFET technology. Our innovative 2D-TFET based NM circuit paves the way toward brain-like energy-efficient computing that can unleash major transformations in future AI and data analytics platforms.

The negative-capacitance field-effect transistor(NC-FET) has attracted tremendous research efforts. However, the lack of a clear physical picture and design rule for this device has led to numerous invalid fabrications. In this work, we address this issue based on an unexpectedly concise and insightful analytical formulation of the minimum hysteresis-free subthreshold swing (SS), together with several important conclusions. Firstly, well-designed MOSFETs that have low trap density, low doping in the channel, and excellent electrostatic integrity, receive very limited benefit from NC in terms of achieving subthermionic SS. Secondly, quantum-capacitance is the limiting factor for NC-FETs to achieve hysteresis-free subthermionic SS, and FETs that can operate in the quantum-capacitance limit are desired platforms for NC-FET construction. Finally, a practical role of NC in FETs is to save the subthreshold and overdrive voltage losses. Our analysis and findings are intended to steer the NC-FET research in the right direction.

The autoionization dynamics of the (2P1/2)ns/d Rydberg states in krypton are investigated using spatially isolated wave-mixing signals generated with a short train of subfemtosecond extreme ultraviolet (XUV) pulses and noncollinear, few-cycle near infrared pulses. Despite ubiquitous quantum beat oscillations from XUV-induced coherences within the excited-state manifold, these wave-mixing spectra allow for the simultaneous evaluation of autoionization lifetimes from a series of Rydberg states above the first ionization potential. Experimentally measured lifetimes of 22 ± 8 fs, 33 ± 6 fs, and 49 ± 6 fs for the wave-mixing signals emitting from the (2P1/2)6d/8s, (2P1/2)7d/9s, and (2P1/2)8d/10s resonances compare favorably with lifetimes for the (2P1/2)6d, 7d, and 8d Rydberg states determined from spectral linewidths. Analysis of the quantum beats reveals that the enhancement of wave-mixing pathways that couple the (2P1/2)nd states to themselves leads to individual reporter state-dependent decays in the wave-mixing signals. The results demonstrate the promise of wave-mixing spectroscopies with subfemtosecond XUV pulses to provide valuable insights into processes governed by electronic dynamics.

The complex behavior of a molecular wave packet initiated by an extreme ultraviolet (XUV) pulse is investigated with noncollinear wave mixing spectroscopy. A broadband XUV pulse spanning 12-16 eV launches a wave packet in H2 comprising a coherent superposition of multiple electronic and vibrational levels. The molecular wave packet evolves freely until a delayed few-cycle optical laser pulse arrives to induce nonlinear signals in the XUV via four-wave mixing (FWM). The angularly resolved FWM signals encode rich energy exchange processes between the optical laser field and the XUV-excited molecule. The noncollinear geometry enables spatial separation of ladder and V- or Λ-type transitions induced by the optical field. Ladder transitions, in which the energy exchange with the optical field is around 3 eV, appear off axis from the incident XUV beam. Each vibrationally revolved FWM line probes a different part of the wave packet in energy, serving as a promising tool for energetic tomography of molecular wave packets. V- or Λ-type transitions, in which the energy exchange is well under 1 eV, result in on-axis nonlinear signals. The first-order versus third-order interference of the on-axis signal serves as a mapping tool of the energy flow pathways. Intra- and interelectronic potential energy curve transitions are decisively identified. The current study opens possibilities for accessing complete dynamic information in XUV-excited complex systems.

Nuclear and electronic dynamics in a wavepacket comprising bound Rydberg and valence electronic states of nitrogen from 12 to 15 eV are investigated using attosecond transient absorption. Vibrational quantum beats with a fundamental period of 50 femtoseconds persist for a picosecond in the b′ 1Σ+u valence state. Multi-state calculations show that these coherences result primarily from near infrared-induced coupling between the inner and outer regions of the b′ 1Σ+u state potential and the dark a″ 1Σ+g state. The excellent spectral and temporal resolution of this technique allows measurement of the anharmonicity of the b′ 1Σ+u potential directly from the observed quantum beats.

Ultrafast nonlinear spectroscopy, which records transient wave-mixing signals in a medium, is a powerful tool to access microscopic information using light sources in the radio-frequency and optical regimes. The extension of this technique towards the extreme ultraviolet (XUV) or even x-ray regimes holds the promise to uncover rich structural or dynamical information with even higher spatial or temporal resolution. Here, we demonstrate noncollinear wave mixing between weak XUV attosecond pulses and a strong near-infrared (NIR) few-cycle laser pulse in gas phase atoms (one photon of XUV and two photons of NIR). In the noncollinear geometry the attosecond and either one or two NIR pulses interact with argon atoms. Nonlinear XUV signals are generated in a spatially resolved fashion as required by phase matching. Different transition pathways can be identified from these background-free nonlinear signals according to the specific phase-matching conditions. Time-resolved measurements of the spatially gated XUV signals reveal electronic coherences of Rydberg wave packets prepared by a single XUV photon or XUV-NIR two-photon excitation, depending on the applied pulse sequences. These measurements open possible applications of tabletop multidimensional spectroscopy to the study of dynamics associated with valence or core excitation with XUV photons.

Coherent narrow-band extreme-ultraviolet (EUV) light is generated by a near-resonant four-wave mixing (FWM) process between attosecond pulse trains and near-infrared pulses in neon gas. The near-resonant FWM process involves one vacuum-ultraviolet (VUV) photon and two near-infrared (NIR) photons and produces new higher-energy frequency components corresponding to the ns/nd to ground-state (2s22p6) transitions in the neon atom. The EUV emission exhibits small angular divergence (2 mrad) and monotonically increasing intensity over a pressure range of 0.5-16 Torr, suggesting phase matching in the production of the narrow-bandwidth coherent EUV light. In addition, time-resolved scans of the NIR nonlinear mixing process reveal the detection of a persistent, ultrafast bound electronic wave packet based on a coherent superposition initiated by the VUV pulse in the neon atoms. This FWM process using attosecond pulses offers a means for both efficient narrow-band EUV source generation and time-resolved investigations of ultrafast dynamics.

An attosecond pulse is used to create a wavepacket in molecular nitrogen composed of multiple bound and autoionizing electronic states of Rydberg and valence character between 12 and 16.7 eV. A time-delayed, few-femtosecond, near-infrared (NIR) laser pulse is used to couple individual states in the wavepacket to multiple neighboring states, resulting in time-dependent modification of the absorption spectrum and revealing both individual quantum beats of the wavepacket and the energy shifts of the excited states in the presence of the strong NIR field. The broad bandwidth of the attosecond pulse and high energy resolution of the extreme ultraviolet spectrometer allow the simultaneous observation of time-dependent dynamics for many individual vibrational levels in each electronic state. Quantum beating with periods from 1.3 to 12 fs and transient line shape changes are observed among vibrational levels of a progression of electronically autoionizing Rydberg states leading to the excited A (2)Πu N2(+) ion core. Vibrational levels in the valence b (1)Πu state exhibit 50 fs oscillation periods, revealing superpositions between individual vibrational levels within this state. Comparisons are made to previous studies of electronic wavepackets in atoms that highlight similarities to atomic behavior yet illustrate unique contributions of the diatomic molecular structure to the wavepacket, including the influence of different electronic potentials and vibrational-level-specific electronic dynamics.

Using attosecond transient absorption, the dipole response of an argon atom in the vacuum ultraviolet (VUV) region is studied when an external electromagnetic field is present. An isolated attosecond VUV pulse populates Rydberg states lying 15 eV above the argon ground state. A synchronized few-cycle near infrared (NIR) pulse modifies the oscillating dipoles of argon impulsively, leading to alterations in the VUV absorption spectra. As the NIR pulse is delayed with respect to the VUV pulse, multiple features in the absorption profile emerge simultaneously including line broadening, sideband structure, sub-cycle fast modulations, and 5-10 fs slow modulations. These features indicate the coexistence of two general processes of the light-matter interaction: the energy shift of individual atomic levels and coherent population transfer between atomic eigenstates, revealing coherent superpositions. An intuitive formula is derived to treat both effects in a unifying framework, allowing one to identify and quantify the two processes in a single absorption spectrogram.

In our study, we identified 288 vascular endothelial cells (VECs) in lung tissue samples, and the abundance of VECs was similar between the RP (184 cells, 1.36%) and control (104 cells, 0.014%) groups. We found that macrophages, mixed lymphocytes, NK cells, and neutrophils are dominant in the cell-cell communication network, which indicates the important roles of those cells in RP development. The severity of pneumonia was scored double-blinded with optical microscopy based on Acute Lung Injury in Animals Study Group [[16]], which scored from 0 to 8: 0, normal; 1-2, alveolar walls slightly broadening, and less than 10 inflammatory cells in high power field of vision; 3-4, alveolar walls significantly broadening, 10-20 inflammatory cells under high power field of vision; 5-6, alveolar walls significantly broadening, inflammatory cells infiltration full of alveolar walls; 7-8, in addition to inflammatory cell infiltration full of alveolar walls, obvious alveolar infiltration. The damaged alveolar cells secrete cytokines, recruit inflammatory cells such as macrophages and lymphocytes to the alveoli and lung interstitium, and induce acute pneumonia, indicating that the development of RP involves an interaction network among multiple types of cells within the microenvironment. A Fabp4 SP high sp macrophage cluster that likely played a fundamental role in normal lung functions enriched in the control lung tissue but largely decreased in the RP lungs, which may be associated with lung injuries caused by irradiation. [Extracted from the article]

Rac GTPases act as master switches to coordinate multiple interweaved signaling pathways. A major function for Rac GTPases is to control neurite development by influencing downstream effector molecules and pathways. In Caenorhabditis elegans, the Rac proteins CED-10, RAC-2 and MIG-2 act in parallel to control axon outgrowth and guidance. Here, we have identified a single glycine residue in the CED-10/Rac1 Switch 1 region that confers a non-redundant function in axon outgrowth but not guidance. Mutation of this glycine to glutamic acid (G30E) reduces GTP binding and inhibits axon outgrowth but does not affect other canonical CED-10 functions. This demonstrates previously unappreciated domain-specific functions within the CED-10 protein. Further, we reveal that when CED-10 function is diminished, the adaptor protein NAB-1 (Neurabin) and its interacting partner SYD-1 (Rho-GAP-like protein) can act as inhibitors of axon outgrowth. Together, we reveal that specific domains and residues within Rac GTPases can confer context-dependent functions during animal development. [ABSTRACT FROM AUTHOR]

Sonodynamic therapy (SDT) with exogenous protoporphyrin IX (PpIX) or endogenous PpIX derived from 5-aminolevulinic acid (ALA) has been carried out to produce apoptotic effects on macrophages, indicating a potential treatment methodology for atherosclerosis. Our previous studies have found that mitochondria damage by reactive oxygen species (ROS) plays a major role in the SDT-induced apoptosis. This study aimed at investigating the potential involvement of the mitochondrial 18 kDa translocator protein (TSPO) and ROS in the pro-apoptotic effects of SDT on THP-1 macrophages. THP-1 macrophages were divided into control and SDT groups, and went through pretreatment of the specific TSPO ligand PK11195 and ROS scavengers N-Acetyl Cysteine (NAC), then compared with groups without pretreatment. Application of PK11195 reduced intracellular accumulation of endogenous PpIX. PK11195 and NAC reduced the generation of intracellular ROS and oxidation of cardiolipin induced by SDT, respectively. PK11195 and NAC also reduced SDT-induced mitochondrial membrane potential (ΔΨm) loss, the translocation of cytochrome c and cell apoptosis. PpIX accumulation, ROS generation and cell apoptosis were also attenuated by siTSPO. Our findings indicate the pivotal role of TSPO and ROS in SDT-induced cardiolipin oxidation, ΔΨm collapse, cytochrome c translocation and apoptosis in THP-1 macrophages. [ABSTRACT FROM AUTHOR]

In this paper, based on our previous multi-pattern uniform resource locator (URL) binary-matching algorithm called HEM, we propose an improved multi-pattern matching algorithm called MH that is based on hash tables and binary tables. The MH algorithm can be applied to the fields of network security, data analysis, load balancing, cloud robotic communications, and so on—all of which require string matching from a fixed starting position. Our approach effectively solves the performance problems of the classical multi-pattern matching algorithms. This paper explores ways to improve string matching performance under the HTTP protocol by using a hash method combined with a binary method that transforms the symbol-space matching problem into a digital-space numerical-size comparison and hashing problem. The MH approach has a fast matching speed, requires little memory, performs better than both the classical algorithms and HEM for matching fields in an HTTP stream, and it has great promise for use in real-world applications. [ABSTRACT FROM AUTHOR]

Exact prediction of Hemorrhagic fever with renal syndrome (HFRS) epidemics must improve to establish effective preventive measures in China. A Seasonal Autoregressive Integrated Moving Average (SARIMA) model was applied to establish a highly predictive model of HFRS. Meteorological factors were considered external variables through a cross correlation analysis. Then, these factors were included in the SARIMA model to determine if they could improve the predictive ability of HFRS epidemics in the region. The optimal univariate SARIMA model was identified as (0,0,2)(1,1,1)12. The R2 of the prediction of HFRS cases from January 2014 to December 2014 was 0.857, and the Root mean square error (RMSE) was 2.708. However, the inclusion of meteorological variables as external regressors did not significantly improve the SARIMA model. This result is likely because seasonal variations in meteorological variables were included in the seasonal characteristics of the HFRS itself. [ABSTRACT FROM AUTHOR]

Human beings are inevitably exposed to ubiquitous phthalate esters (PAEs). Processed, packaged foods are popular nowadays, in which emulsifiers are frequently added as food additives. It is unclear how emulsifiers affect the bioavailability of ingested PAEs contaminants and their toxicities. The purposes of our study were to explore whether food emulsifier Glycerin Monostearate (GMS) could increase the internal exposure levels of six priority controlled PAEs and affect their reproductive toxicities when male rats are exposed to PAEs mixture (MIXPs). The male rats were exposed to MIXPs by gavage for thirty days in combination with or without given GMS. Phthalate monoesters (MPAEs), primary metabolites of PAEs, in rat urine were used as biomarkers to predict the internal exposure levels of the six PAEs, and their concentrations were determined using UPLC-MS. The reproductive toxicity was evaluated using serum testosterone levels test and histopathology of testes. Results showed that compared to PAEs exposure alone, the internal exposure levels of PAEs increased by 30%-49% in the presence of GMS. PAEs exposure led to the reduction of testosterone level by 23.4%-42.1% in the presence and absence of GMS, respectively, compared to the baseline. Testosterone levels in MIXPs+GMS and DEHP+GMS group were decreased by 9.1% and 13.6%, respectively, compared with MIXPs and DEHP group. Histopathology showed that injuries of testis (deciduous spermatids) were observed, and GMS exacerbated the injuries. The results indicated food emulsifiers chronically taken up might increase safety risks of food PAEs contaminants. [ABSTRACT FROM AUTHOR]

Background and Purpose: The conflicting findings of previous morphological and hemodynamic studies on intracranial aneurysm rupture may be caused by the relatively small sample sizes and the variation in location of the patient-specific aneurysm models. We aimed to determine the discriminators for aneurysm rupture status by focusing on only posterior communicating artery (PCoA) aneurysms. Materials and Methods: In 129 PCoA aneurysms (85 ruptured, 44 unruptured), clinical, morphological and hemodynamic characteristics were compared between the ruptured and unruptured cases. Multivariate logistic regression analysis was performed to determine the discriminators for rupture status of PCoA aneurysms. Results: While univariate analyses showed that the size of aneurysm dome, aspect ratio (AR), size ratio (SR), dome-to-neck ratio (DN), inflow angle (IA), normalized wall shear stress (NWSS) and percentage of low wall shear stress area (LSA) were significantly associated with PCoA aneurysm rupture status. With multivariate analyses, significance was only retained for higher IA (OR = 1.539, p < 0.001) and LSA (OR = 1.393, p = 0.041). Conclusions: Hemodynamics and morphology were related to rupture status of intracranial aneurysms. Higher IA and LSA were identified as discriminators for rupture status of PCoA aneurysms. [ABSTRACT FROM AUTHOR]

Background: Pancreatitis is the most common complication of endoscopic retrograde cholangiopancreatography (ERCP) which can be severe and cause death in approximately 10% of cases. Up to now, six randomized controlled trials (RCTs) have been found relevant to the effect of allopurinol on prevention of Post-ERCP pancreatitis (PEP). However, these results remained controversial. Objective: To conduct a meta-analysis with RCTs published in full text to determine the effectiveness of prophylactic allopurinol of different dosages and administration time in the incidence and severity of PEP. Methods: Literature search was performed in PubMed, Embase, Web of Science and Cochrane Library from databases inception to May 2014. RCTs comparing the effect of allopurinol with placebo on prevention of PEP were included. Statistical heterogeneity was quantitatively evaluated byχ2 test with the significance set P<0.10 or I2>50%. Results: Six RCTs consisting of 1974 participants were eventually included. The incidences of PEP in allopurinol group and placebo group were 8.4%(83/986) and 9.9%(98/988) respectively. Meta-analysis showed no evident prevention effect of allopurinol on the incidence of PEP (RR 0.75, 95%CI 0.39–1.42) with significant heterogeneity (I2 = 70.4%, P = 0.005). When studies were stratified according to the dosages and administration time of allopurinol they applied, there was still no evident prevention effect of allopurinol on mild, moderate or severe PEP. However, statistically substantial heterogeneity was presented in the subgroup of moderate PEP when the effect of high dose of allopurinol was analyzed (Imoderate2 = 82.3%, Pmoderate = 0.018). Statistically significant heterogeneity was also observed in subgroup of mild PEP, when the effect of long adminstration time of allopurinol was investigated (Imild2 = 62.8%, Pmild = 0.068). Conclusion: The prophylactic use of allopurinol in different dosages and administration time had no effect in preventing incidence and severity of PEP. [ABSTRACT FROM AUTHOR]