Reconfigurable logic in nanosecond Cu/GeTe/TiN filamentary memristors for energy-efficient in-memory computing.

Owing to the capability of integrating the information storage and computing in the same physical location, in-memory computing with memristors has become a research hotspot as a promising route for non von Neumann architecture. However, it is still a challenge to develop high performance devices as well as optimized logic methodologies to realize energy-efficient computing. Herein, filamentary Cu/GeTe/TiN memristor is reported to show satisfactory properties with nanosecond switching speed (<60 ns), low voltage operation (<2 V), high endurance (>104 cycles) and good retention (>104 s @85 °C). It is revealed that the charge carrier conduction mechanisms in high resistance and low resistance states are Schottky emission and hopping transport between the adjacent Cu clusters, respectively, based on the analysis of current-voltage behaviors and resistance-temperature characteristics. An intuitive picture is given to describe the dynamic processes of resistive switching. Moreover, based on the basic material implication (IMP) logic circuit, we proposed a reconfigurable logic method and experimentally implemented IMP, NOT, OR, and COPY logic functions. Design of a one-bit full adder with reduction in computational sequences and its validation in simulation further demonstrate the potential practical application. The results provide important progress towards understanding of resistive switching mechanism and realization of energy-efficient in-memory computing architecture.

Citrobacter freundii induces sepsis with new-onset status seizure in an adult: A case report and literature review.

RATIONALE: Sepsis with brain abscess induced by Citrobacter freundii in adults has rarely been reported and is extremely pathogenic with a high mortality rate. Early diagnosis of the infection still remains challenging. PATIENT CONCERNS: A 27-year-old woman was transferred to our emergency department for fever, status seizure and refractory hypotension. Administration of midazolam, propofol and sodium valproate could not attenuate the seizure except for the addition of vecuronium. The blood white blood cell count was 42.91 (109/L) with 80% neutrophils, and procalcitonin was 22.46ng/mL. DIAGNOSES: Both deoxyribonucleic acid and ribonucleic acid of C freundii were detected in blood by metagenomic next-generation sequencing of pathogens,the diagnosis of septic shock and brain abscess caused by C freundii was highly suspected. INTERVENTIONS: On day 1, antibiotics of cefoperazone sodium and sulbactam sodium 6g/day, immunoglobulin, and hydrocortisone were used with suspected septic shock. Continuous renal replacement therapy was used to eliminate excessive lactate, ammonia, myohemoglobin and creatinine. On day 2, a brain computed tomography scan revealed multiple patchy slightly low densities in the brain, antibiotics were adjusted to meropenem intravenously 3g/day. OUTCOMES: On day 2, a brain computed tomography scan revealed multiple patchy slightly low densities in the brain, she died on day 3. LESSONS: Clinicians should consider the possibility of brain abscess when evaluating a patient with new-onset dizziness, fever, seizure, or other neurologic symptoms or signs, especially for patients whose mental status changes. metagenomic next generation sequencing and resistance genes could be considered when cerebrospinal fluid or blood results are negative and clinical manifestations are highly suspected of infection or when the treatment time is limited.

[The effect of different methods of counting of rescue crew on the quality of cardiopulmonary resuscitation].

OBJECTIVE: To compare the effective power of external chest compression and degree of exhaustion of rescue crew using different methods of counting, in order to establish a more appropriate and standard method of counting. METHODS: Forty-eight subjects who had received formal training in basic life support (BLS) and advanced life support (ALS) were recruited randomly from doctors and nurses working in the emergency departments. The methods of counting were randomly selected which was performed first, and then they performed continuous chest compressions for 3 minutes using two different methods of counting with 30 minutes apart on the manikin, which was used in the hospital for cardiopulmonary resuscitation (CPR) training. The total number of compressions was recorded, and the number of those which were considered satisfactory, the peak heart rate of the performer and the time to reach peak heart were all recorded. Feeling of fatigue and discomfort was evaluated by self-reported survey results with the use of a visual analogue scale (VAS). RESULTS: The total number of compressions attempted, the effective power of external chest compression and the mean compression depth when rescuers counted form 1 to 10, which were repeated for 3 times, were greater than those when rescuers counted from 1 to 30 during 3 minutes of CPR [(202.40+/-6.52) times vs. (173.50+/-5.68) times, (67.48+/-2.00)% vs. (57.81+/-2.00)%, (4.45+/-0/.34) cm vs. (4.05+/0.21) cm, all P<0.01]. The VAS scores (22.15+/-3.09) was lower than that when rescuers counted them from 1 to 30 (31.10+/-4.09, P<0.01). The time to reach peak heart rate [(124.88+/-5.40) s] was longer than that when rescuers counted them from 1 to 30 [(106.15+/-6.80) s, P<0.01]. There was no difference in peak heart rate between two methods of counting. CONCLUSION: The effective power of external chest compression is greater when rescuers counted from 1 to 10 with repetition for 3 times than that when rescuers counted continuously from 1 to 30 during CPR. The method of counting from 1 to 10 with repetition for 3 times can save physical energy of rescue crew, so it can improve the quality of CPR to some extent.

An electro-photo-sensitive synaptic transistor for edge neuromorphic visual systems.

The practical application of optoelectronic artificial synapses in neuromorphic visual systems is still hindered by their limited functionality, reliability and the challenge of mass production. Here, an electro-photo-sensitive synapse based on a highly reliable amorphous InGaZnO thin-film transistor is demonstrated. Not only does the synapse respond to electrical voltage spikes due to charge trapping/detrapping, but also the weight is modified directly by persistent photocurrent effects under UV-light stimulation. Representative forms of synaptic plasticity, including inhibitory and excitatory postsynaptic currents, frequency-dependent characteristics, short-term to long-term plasticity transitions, and summation effects, are successfully demonstrated. In particular, optoelectronic synergetic modulation leads to reconfigurable excitatory and inhibitory synaptic behaviors, which provides a promising way to achieve the homeostatic regulation of synaptic weights. Moreover, the analogue channel conductance with 100 states is used as the weight update rule to perform MNIST handwritten digit recognition, using system-level LeNet-5 convolutional neural network simulations. The network shows a high recognition accuracy of 95.99% and good tolerance to noisy input patterns. This study highlights the commercial potential of mature optoelectronic InGaZnO transistor technology in edge neuromorphic systems.

Nonvolatile reconfigurable sequential logic in a HfO2 resistive random access memory array.

Resistive random access memory (RRAM) based reconfigurable logic provides a temporal programmable dimension to realize Boolean logic functions and is regarded as a promising route to build non-von Neumann computing architecture. In this work, a reconfigurable operation method is proposed to perform nonvolatile sequential logic in a HfO2-based RRAM array. Eight kinds of Boolean logic functions can be implemented within the same hardware fabrics. During the logic computing processes, the RRAM devices in an array are flexibly configured in a bipolar or complementary structure. The validity was demonstrated by experimentally implemented NAND and XOR logic functions and a theoretically designed 1-bit full adder. With the trade-off between temporal and spatial computing complexity, our method makes better use of limited computing resources, thus provides an attractive scheme for the construction of logic-in-memory systems.

[Pharmacokinetic characteristics of ferulic acid in patients with different syndromes of deficiency of spleen qi, stagnation of liver qi and spleen deficiency, and excess of stomach heat].

OBJECTIVE: To investigate the nature of syndrome of traditional Chinese medicine by means of pharmacokinetic (PK) method. METHODS: Twenty-one healthy volunteers, 20 patients with syndrome of stagnation of liver qi and spleen deficiency, 22 patients with syndrome of deficiency of spleen qi and 19 patients with syndrome of excess of stomach heat were included and administered to take Jiawei Xiaoyaosan Recipe (JWXYSR). The serum PK parameters of ferulic acid (FA) were examined by high performance liquid chromatography (HPLC) method. RESULTS: The absorption rate constant (alpha) and the elimination rate constant (beta) were both decreased while the apparent first-order absorption constant (K(a)) was enhanced significantly in the patients with syndrome of deficiency of spleen qi; the alpha, beta and Ka were all reduced in the patients with syndrome of stagnation of liver qi and spleen deficiency; the beta and K(a) were increased in the patients with syndrome of excess of stomach heat, as compared with the corresponding PK parameters in the healthy volunteers (P<0.01). CONCLUSION: The PK analysis of FA in the patients with syndrome of deficiency of spleen qi shows that the absorption rate is accelerated, and both the distribution and elimination rates are slowed down. The absorption, distribution and elimination rates of AF are all slowed down in the patients with syndrome of stagnation of liver-qi and spleen deficiency, while the absorption and elimination rates of AF are both accelerated in the patients with syndrome of excess of stomach heat. There are obvious differences in the PK characteristics among these three syndromes.

Realization of Functional Complete Stateful Boolean Logic in Memristive Crossbar.

Nonvolatile stateful logic computing in memristors is a promising paradigm with which to realize the unity of information storage and processing in the same physical location that has shown great feasibility for breaking the von Neumann bottleneck in traditional computing architecture. How to reduce the computational complexity of memristor-based logic functions is a matter of concern. Here, based on a general logic expression, we proposed a method to implement the arbitrary logic of complete 16 Boolean logic in two steps with one memristor in the crossbar architecture. A representative functional complete NAND logic is successfully experimentally demonstrated in the filamentary Ag-AgGeTe-Ta memristors to prove the validity of our method. We believe our work may promote the development of the revolutionary logic in memory architectures.

CFP10 and ESAT6 aptamers as effective Mycobacterial antigen diagnostic reagents.

The development of effective Mycobacterial antigen diagnostic reagents remains a high priority. The 6-kDa early secreted antigenic target (ESAT6) and 10-kDa culture filtrate protein (CFP10) are secreted early by virulent Mycobacterium tuberculosis (M. tb) and are not present in the non-virulent Bacillus Calmette-Guerin (BCG). In this study, we used a Systematic Evolution of Ligands by Exponential Enrichment (SELEX) technique to screen for a functional ssDNA aptamer "antibody" that specifically bound to ESAT6-CFP10 (CE) protein. The selected single ssDNA aptamers (CE24 and CE15) demonstrated the highest specificity and binding affinity to CFP10 (CE24: Kd = 3.75 × 10(-7) M) and ESAT6 (CE15: Kd = 1.6 × 10(-7) M). We further detected CFP10 and ESAT6 proteins in serum samples from active pulmonary tuberculosis (TB) patients, extrapulmonary TB patients and healthy donors by using an enzyme-linked oligonucleotide assay (ELONA). The results showed that the sensitivity and specificity were 100% and 94.1% (using CE24 aptamer-based ELONA) and 89.6% and 94.1% (using CE15 aptamer-based ELONA), respectively. A good correlation was observed between aptamer-based ELONA and T-SPOT TB assay. Thus, our study suggests that CE24 and CE15 have potentially broad applications as early antigen diagnostic agents not only for active pulmonary TB, extrapulmonary TB, but also possibly for latent TB infection and TB with immune-deficiency.