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Background/Purpose: This study reports the long‐term results of a phase II trial evaluating the clinical efficacy of neoadjuvant gemcitabine, nab‐paclitaxel, and S1 (GAS) in borderline resectable pancreatic cancer with arterial contact (BRPC‐A). Methods: A multicenter, single‐arm, phase II trial was conducted. Patients received six cycles of GAS and patients without progressive disease were intended for R0 resection. Results: Of the 47 patients, 45 (96%) underwent pancreatectomy. At the time of this analysis, all patients were updated with no loss to follow‐up. A total of 30 patients died, while the remaining 17 patients were followed for a median of 68.1 months. The updated median overall survival (OS) was 41.0 months, with 2‐ and 5‐year OS rates of 68.0% and 44.6%, respectively. Multivariate analysis in the preoperative model showed that a tumor diameter reduction rate ≥10% and a CA19‐9 reduction rate ≥95% after neoadjuvant chemotherapy remained independently associated with favorable survival. In the postoperative multivariate model, no lymph node metastasis, no major surgical complications, and completion of adjuvant chemotherapy were independently associated with improved OS. Conclusions: This long‐term evaluation of the neoadjuvant GAS trial demonstrated the high efficacy of the regimen, suggesting that it is a promising treatment option for patients with BRPC‐A. [ABSTRACT FROM AUTHOR]

Suprapancreatic lymph node dissection for patients with gastric cancer in whom the common hepatic artery is located neither at the suprapancreatic margin nor in front of the portal vein is a more difficult procedure than when the common hepatic artery is in a more typical position. There is an increased risk of injury to the vessels that need to be preserved and inadequate lymph node dissection. Measures that have been reported for use in this situation are preoperative diagnosis with three‐dimensional computed tomography angiography, dissection using the portal vain as a guide, and safe exposure of the portal vein with dissection to preserve the nerves at the suprapancreatic margin and in front of the portal vein. We review the literature and report our experience with a patient whose common hepatic artery was not located in the suprapancreatic margin who safely underwent suprapancreatic lymph node dissection using these methods. [ABSTRACT FROM AUTHOR]

Circulating tumor cells (CTCs) derived from any tumor tissue could contribute to metastasis and resistance to cancer treatments. In this study, we performed single‐cell next‐generation sequencing of CTCs and evaluated their usefulness for characterizing tumor biology and the mechanisms of metastasis in neuroblastomas (NB). We aimed to isolate CTCs from 10 patients with NB at diagnosis before any treatments and four patients at relapse. GD2+CD90+CD45−CD235a−DAPI− cells were isolated as neuroblastoma CTCs using fluorescence‐activated cell sorting. In five patients with advanced stages (M stage), DNA and RNA sequencing of CTCs at single‐cell level were performed. NB CTCs were isolated from eight of the 10 patients at diagnosis and three of the four patients at relapse. More CTCs could be isolated from patients with advanced stages. In one patient, ALK mutation (p.F1174L), was identified in both tumor tissue and a CTC. In patients with MYCN amplification, this gene was amplified in 12 of 13 CTCs. Using single‐cell RNA sequencing, angiogenesis‐related and cell cycle‐related genes together with CCND1 and TUBA1A genes were found to be upregulated in CTCs. In one patient, CTCs were divided into two subgroups showing different gene expression profiles. In one subgroup, cell cycle‐related and proliferation‐related genes were differentially upregulated compared with the other group. In conclusion, next‐generation sequencing of CTCs at single‐cell level might help to characterize the tumor biology and the mechanisms of metastasis in NB. [ABSTRACT FROM AUTHOR]

Background/Purpose: The aim of this study was to assess whether the duration of adjuvant gemcitabine plus S‐1 (GS) chemotherapy has any effect on survival in patients with pancreatic ductal adenocarcinoma (PDAC). Methods: Of the 290 patients who received adjuvant GS chemotherapy, 100 (34%) received the standard duration (20‐29 weeks) and 190 (66%) received an extended duration (≥30 weeks). To reduce selection bias, the prognostic impact (recurrence‐free survival [RFS] and overall survival [OS]) based on the duration of adjuvant GS chemotherapy was analyzed using inverse probability of treatment weighting (IPTW). Moreover, to reduce immortal time bias, time‐dependent multivariate analyses in which implementation of adjuvant GS chemotherapy was treated as time‐varying covariate was also performed. Results: Extended duration of adjuvant GS chemotherapy was significantly correlated with prolonged RFS (P <.001) and OS (P <.001) after IPTW adjustment. Time‐dependent multivariate analyses revealed that extended duration of adjuvant GS chemotherapy was an independent prognostic factor for prolonged RFS (hazard ratio [HR], 0.58, P =.002) and OS (HR, 0.56, P =.005). Conclusion: Extended duration (≥30 weeks) of adjuvant GS chemotherapy in patients with PDAC was associated with an improved prognosis. These findings warrant a further prospective trial on PDAC to investigate the survival benefit of extended adjuvant chemotherapy. [ABSTRACT FROM AUTHOR]

Introduction: Although recent echocardiographic studies have suggested that left atrial appendage (LAA) remodeling contributes to the development of LAA thrombus (LAAT), histological evidence is absent. The objective of this study was to examine clinical parameters and histological findings to clarify the factors involved in LAAT formation. Methods: A total of 64 patients (no atrial fibrillation [AF], N = 22; paroxysmal AF, N = 16; nonparoxysmal AF, N = 26) who underwent LAA excision during surgery were enrolled. Transthoracic and transesophageal echocardiography were performed before surgery. We evaluated the fibrosis burden (%) in the excised LAA sections with Azan–Mallory staining in patients with a LAAT compared with those without. Results: Patients with paroxysmal and non‐paroxysmal AF had a higher LAA fibrosis burden than those without AF (p =.005 and p <.0001, respectively). Among the patients enrolled, 16 had a LAAT and 15 of them had nonparoxysmal AF. Among the nonparoxysmal AF patients, those with a LAAT had significantly higher LAA fibrosis burden than those without (23.8% [14.8%–40.3%] vs. 12.8% [7.4%–18.2%], p =.004) and echocardiographic parameters of the left atrial volume index (R = 0.543, p =.01), LAA depth (R = 0.452, p =.02), and LAA flow velocity (R = − 0.487, p =.01) were correlated with the LAA fibrosis burden. Conclusion: This study provided histological evidence that LAA fibrosis is related to LAAT formation. Echocardiographic parameters of LAA remodeling and function were correlated with the LAA fibrosis burden. [ABSTRACT FROM AUTHOR]

Summary: The generative adversarial network is widely used in image generation, and the generation of images with different styles is applied to underwater image enhancement. The existing underwater image generative adversarial network does not realize color correction when processing underwater images Therefore, we propose an improved generative adversarial network for image color restoration. Firstly, the loss function in the network is improved to train the dataset. Then the improved network is used to detect the underwater image. After network testing, the underwater image is more satisfactory than the traditional image. Numerical results show that this method has a good color restoration and sharpening effects. [ABSTRACT FROM AUTHOR]

Objective: Whether oral health care during the perioperative period can lead to a better outcome after heart valve surgery has not been adequately elucidated. We examined the effects of perioperative oral care on postoperative inflammation response in patients who underwent heart valve surgery. Materials and Methods: In this retrospective cohort study, 223 patients scheduled for single valve heart surgery were divided into the oral care, who underwent professional teeth cleaning or scaling within 3 days prior to surgery, and also following surgery at least twice a week (n = 111), and non‐oral care (n = 112) groups. After propensity score matching, records of both groups (80:80) were examined after surgery to evaluate inflammation markers (white blood cell count [WBC], neutrophil/white blood cell ratio [NWR], C‐reactive protein [CRP] level, body temperature [BT]). Results: WBC, NWR, CRP level, and BT were increased in both groups the day following surgery. Thereafter, CRP level, WBC, NWR, and BT on various days after surgery in the oral care group showed greater decreases as compared to the non‐oral care group. Conclusions: Perioperative oral health care can decrease postoperative inflammation in patients undergoing heart valve surgery and may be important to ensure a better outcome in those patients. [ABSTRACT FROM AUTHOR]

Introduction: The International Guidelines for Groin Hernia Management recommends an anterior repair after a failed posterior repair, and laparoscopic repair after a failed anterior tissue repair or Lichtenstein repair. However, there are not enough studies to guide decision‐making for patients with recurrent hernia patients after combined anterior‐posterior repair. We investigate the safety and usefulness of transabdominal preperitoneal repair (TAPP) for recurrent hernia patients after failed anterior‐posterior repair. Methods: We conducted a retrospective analysis of 13 consecutive patients with recurrent groin hernia who underwent TAPP after prior anterior preperitoneal mesh repair (that created anterior and posterior scarring) between September 2013 and October 2018. The control group comprised 45 patients who underwent TAPP for recurrent hernia after anterior repair (43 nonmesh repairs and two Lichtenstein repairs). Results: There were no intraoperative complications, and chronic pain was not reported by the patients with prior anterior preperitoneal mesh repair. The mean operative time was 113 ± 31.3 minutes, and the mean postoperative stay was 1.62 ± 0.87 days. The Wong–Baker FACES rating scale score for pain on postoperative day 1 was 1.91 ± 1.5; on postoperative day 7, the score was 1.0 ± 0.89. None of these findings was significantly different from the findings in patients who had a prior anterior repair. A single patient experienced a further recurrence and underwent repeat TAPP. Conclusions: The use of TAPP after failed combined anterior‐posterior mesh repair may be feasible and safe for recurrent groin hernia. Further study is needed to determine long‐term outcomes. [ABSTRACT FROM AUTHOR]

Open heart transcatheter mitral valve implantation using the Edwards‐Sapien 3 for mitral annular calcification is a safe procedure, because surgeons do not have to decalcify. And also, surgeons can resect the anterior mitral leaflet to prevent left ventricular outflow tract obstruction and deploy the valve under direct visualization. [ABSTRACT FROM AUTHOR]

A 55‐year‐old woman with a history of right hepatic lobectomy via a Benz incision presented for evaluation of a new abdominal bulge in the right upper quadrant. We diagnosed an incisional hernia, but because we could neither reduce the hernia contents nor locate the orifice, we performed a laparoscopic evaluation. Laparoscopy revealed subcostal herniation of the greater omentum via a 2‐cm defect on the caudal side of the right ribs, which we repaired using a Ventralex ST Hernia Patch. Laparoscopic placement of this mesh with straps allowed for reliable deployment, fixation, and confirmation of defect closure, including the cranial aspect—often a major challenge in subcostal hernia repair. [ABSTRACT FROM AUTHOR]

Background: One of the most severe pancreatic surgery complications is post-pancreatectomy hemorrhage (PPH). This study's aim was to evaluate the efficacy of flooring the major vessels with falciform ligament in preventing PPH after pancreatoduodenectomy (PD). Methods: This study was a retrospective review of 500 consecutive patients who underwent PD between Jan 2010 and Dec 2019 at Hiroshima University. Morbidities, including postoperative pancreatic fistula (POPF) or PPH and 90-day mortality, were analyzed. The study cohort was divided into two groups based on the time of surgery (2010–2016 and 2017–2019), i.e., before and after implementation of falciform ligament flooring method. The patient characteristics, operative parameters, clinicopathological factors, morbidity, and mortality were compared between the two periods. Results: Morbidity and mortality rates in the entire cohort were 21% and 1.4%, respectively. The incidence of Grade B/C POPF and PPH was 9.0% and 3.8%, respectively. There was no significant difference between the two periods with respect to Grade B/C POPF, morbidity rate, and mortality rate; however, the rate of Grade B/C PPH significantly decreased from 5.2 to 1.6% p =.027. On multivariate analysis, the absence of the falciform ligament flooring method was an independent PPH risk factor p =.003. Conclusions: Falciform ligament flooring method may help decrease the incidence of PPH after PD. [ABSTRACT FROM AUTHOR]

Background: The frequency and prognosis of resected deficient mismatch repair (dMMR) pancreatic ductal adenocarcinoma (PDAC) remain unclear. This study was designed to assess the frequency of dMMR and its clinicopathological relevance in Japanese patients with PDAC treated with surgical resection. Methods: A total of 400 consecutive patients with PDAC who underwent surgical resection at Hiroshima University were enrolled. Immunohistochemical staining with four antibodies including MLH1, MSH2, MSH6, and PMS2 was used to determine the presence of dMMR in PDAC specimens. Statistical analyses were applied to evaluate the frequency and clinical outcomes of these patients. Results: Of these 400 patients, five (1.3%) had dMMR (two had MLH1 deficiency, two had PMS2 deficiency, and one had MSH2 deficiency). We found a significantly different histological differentiation pattern between patients with dMMR and those with proficient mismatch repair (pMMR) (P =.03). Univariate survival analysis revealed no significant differences between dMMR and pMMR in recurrence‐free survival (P =.268) or overall survival (P =.173). Conclusions: The incidence of dMMR in Japanese patients with resected PDAC is low, and we found no ethnic‐specific differences when comparing the incidence to that in Caucasian patients. In the current study, no significant difference was found in recurrence‐free and overall survival between patients with dMMR and pMMR. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to assess the validity of surgical resection for patients with pancreatic ductal adenocarcinoma (PDAC) aged ≥80 years stratified by resectability status. Methods: Medical records of 245 patients with resectable (R) and 169 with borderline resectable/unresectable (BR/UR) PDAC were reviewed retrospectively. Of the total of 414 patients, 56 (14%) were ≥80 years. The prognostic impact of age ≥80 years was analyzed with stratification by resectability status. Results: No significant difference was found in the incidence of major complications between patients aged ≥80 versus <80 years (12% vs. 16% respectively; P = 0.53). However, patients aged ≥80 years were significantly less likely to receive adjuvant gemcitabine + S‐1 chemotherapy than those <80 years (39% vs. 83%, respectively; P < 0.001). Multivariate analyses identified age ≥80 years as an independent risk factor for poor survival in the BR/UR group (P = 0.01), whereas it did not affect survival in the R group. Conclusion: Patients aged ≥80 years had a similar prognosis to <80 years in R PDAC, whereas they had significantly worse prognosis in BR/UR PDAC. These findings suggest that surgical resection for patients with PDAC aged ≥80 years is validated in R PDAC, whereas its survival benefit might be limited in BR/UR PDAC. [ABSTRACT FROM AUTHOR]

BACKGROUND Physical activity (PA) has long been acknowledged to contribute health benefits among children. However, research has consistently shown that PA declines as children grow older. Thus, this study examined the factors which are associated to children's PA in order to identify potential barriers to PA. METHODS: Using data from the KidQuest Program, we conducted bivariate and multivariate analyses on survey data collected from fifth to seventh grade students in a small Midwestern city. RESULTS: We found that food knowledge, eating breakfast, and talking with family about eating healthy foods, are positively related to PA. On the other hand, screen time is negatively related to PA. In addition, our results evinced differences between ethnicities and found that Latino children's screen time affects their PA levels more than their white counterpart. CONCLUSIONS: There are different factors which can be tapped to increase PA among middle school‐aged children. Given the differences between the Latino and white samples especially in screen time, schools should consider individualized intervention, rather than a "one size fits all" program, to increase PA participation. [ABSTRACT FROM AUTHOR]

Abstract: A series of ester‐linked tetracarboxylic dianhydrides (TA‐X) were synthesized from trimellitic anhydride chloride and 4,4′‐biphenol analogs containing different numbers and positions of methyl substituents. Aromatic poly(ester imide)s (PEsIs) were polymerized from TA‐Xs and 2,2′‐bis(trifluoromethyl)benzidine to investigate the film properties systematically. A significant substituent effect on the target properties (Tg, optical transparency, the linear coefficient of thermal expansion (CTE) and ductility) was observed. A PEsI containing 2,2′,3,3′,5,5′‐hexamethyl‐substituted p‐biphenylene units was chemically imidized in a homogeneous state. It was highly soluble at room temperature, even in less hygroscopic non‐amide solvents such as cyclopentanone (CPN), and provided a stable CPN solution with a high solid content. The CPN‐cast PEsI film was almost colorless as suggested from the rather low yellowness index (3.2), high light transmittance at 400 nm (71.5%) and very low haze (1.15%). This PEsI film also had a high Tg (294 °C, determined by thermomechanical analysis) in addition to a low CTE (21.7 ppm K−1), moderate film ductility and very low water uptake. A structural modification of the PEsI by copolymerization with a tetracarboxylic dianhydride with a rigid/linear structure was effective in further reducing the CTE while maintaining the other excellent target properties. Thus, some of the PEsIs developed in this work are promising candidates as novel plastic substrates for use in image display devices. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

During cardiopulmonary bypass (CPB), blood viscosity conspicuously increases and decreases due to changes in hematocrit and blood temperature. Nevertheless, blood viscosity is typically not evaluated, because there is no technology that can provide simple, continuous, noncontact monitoring. We modeled the pressure-flow characteristics of an oxygenator in a previous study, and in that study we quantified the influence of viscosity on oxygenator function. The pressure-flow monitoring information in the oxygenator is derived from our model and enables the estimation of viscosity. The viscosity estimation method was proposed and investigated in an in vitro experiment. Three samples of whole bovine blood with different hematocrit levels (21.8, 31.0, and 39.8%) were prepared and perfused into the oxygenator. As the temperature changed from 37°C to 27°C, the mean inlet pressure ( Pin) and outlet pressure ( Pout) of the oxygenator and the flow (Q) and viscosity of the blood were measured. The estimated viscosity was calculated from the pressure gradient (Δ P = Pin − Pout) and Q and was compared to the measured blood viscosity. A strong correlation was found between the two methods for all samples. Bland-Altman analysis revealed a mean bias of −0.0263 mPa.s, a standard deviation of 0.071 mPa.s, limits of agreement of −0.114-0.166 mPa.s, and a percent error of 5%. Therefore, this method is considered compatible with the torsional oscillation viscometer that has plus or minus 5% measurement accuracy. Our study offers the possibility of continuously estimating blood viscosity during CPB. [ABSTRACT FROM AUTHOR]

ABSTRACT Periodic crazes are caused in a polymer film by the unique mechanical method using bending. Generation of a craze depends on entanglements of the molecular chains of a polymer. Therefore, control of composite morphology of periodic crazes was attempted by varying the entanglements of molecular chains. An effective entanglement network became sparse by polymer blends of an ultra-high molecular weight polymethylmethacrylate (PMMA) and a low molecular weight PMMA. Consequently, the composite morphology of periodic crazes caused in the blend film varied. In other words, the periodic craze can be used for the evaluation of the effective entanglements. In addition, it was figured out that PMMA of which the number-average molecular weight ( Mn) is less than twice of the effective entanglement molecular weight ( Me*) works as a plasticizer in the blend film. And also, it was revealed that the mechanical properties of the blend film decreased dramatically at Mn ≒ 6 Me*. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44332. [ABSTRACT FROM AUTHOR]

Ectopic gene expression, or the gain-of-function approach, has the advantage that once the function of a gene is known the gene can be transferred to many different plants by transformation. We previously reported a method, called FOX hunting, that involves ectopic expression of Arabidopsis full-length cDNAs in Arabidopsis to systematically generate gain-of-function mutants. This technology is most beneficial for generating a heterologous gene resource for analysis of useful plant gene functions. As an initial model we generated more than 23 000 independent Arabidopsis transgenic lines that expressed rice fl-cDNAs (Rice FOX Arabidopsis lines). The short generation time and rapid and efficient transformation frequency of Arabidopsis enabled the functions of the rice genes to be analyzed rapidly. We screened rice FOX Arabidopsis lines for alterations in morphology, photosynthesis, element accumulation, pigment accumulation, hormone profiles, secondary metabolites, pathogen resistance, salt tolerance, UV signaling, high light tolerance, and heat stress tolerance. Some of the mutant phenotypes displayed by rice FOX Arabidopsis lines resulted from the expression of rice genes that had no homologs in Arabidopsis . This result demonstrated that rice fl-cDNAs could be used to introduce new gene functions in Arabidopsis. Furthermore, these findings showed that rice gene function could be analyzed by employing Arabidopsis as a heterologous host. This technology provides a framework for the analysis of plant gene function in a heterologous host and of plant improvement by using heterologous gene resources. [ABSTRACT FROM AUTHOR]

This paper discusses a noise suppressor for use in the standard AMR (adaptive multi-rate) voice codec in 3GPP (3rd Generation Partnership Project). The performance standards (TS 26.077) for 3GPP noise suppressors require both high quality and high noise suppression performance with limited computational complexity. This paper is based on the spectral subtraction method, and discusses the configuration in which spectral subtraction and amplitude suppression are mutually controlled according to the state of the input signal. The improved estimation of the subband S/N (signal-to-noise ratio) for use in the control of spectral subtraction and amplitude suppression is also discussed. The proposed method is evaluated through simulation experiments, and its effectiveness is verified. Subjective evaluation tests (evaluation by third parties) and objective evaluation tests were performed in accordance with 3GPP TS 26.077, and all 3GPP performance requirement standards were met. The system obtained the first performance endorsement from 3GPP in March 2002. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(14): 90–102, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20212 [ABSTRACT FROM AUTHOR]

In this paper, the authors propose three new excitation codebook search methods for suppressing the selection of an excitation code vector that has a high likelihood of producing pulse-like degraded sound in a low-bit-rate CELP coder that uses a pulse-like excitation code vector. The proposed methods are (1) adaptive weighting for coding distortion based on the state of the input speech, (2) weighting for coding distortion due to amplitude distribution distortion in the time direction, and (3) setting an upper limit for the coding distortion rate for pulse-like excitation codebook searches. Although an excitation code vector with large coding distortion is selected if these proposed methods are set from the coding distortion minimization standard that is used in a conventional CELP excitation code vector search, there is an improvement in the quality that is perceived by the sense of hearing. The authors applied the proposed methods to a 4-kbps CELP coder to verify their effectiveness according to subjective quality evaluation experiments. The results verified the effectiveness of the proposed methods by showing that the introduction of the proposed methods improved the MOS value by approximately 0.3 for clean speech and by approximately 0.4 for noise-added speech. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(8): 1–10, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20739 [ABSTRACT FROM AUTHOR]

Aberrant mRNAs containing premature termination codons (PTC-mRNAs) are degraded by a conserved surveillance system, referred to as the nonsense-mediated decay (NMD) pathway. Although NMD is reported to operate on the decapping and 5'-to-3' exonucleolytic decay of PTC-mRNAs without affecting deadenylation, a role for an opposite 3'-to-S' decay pathway remains largely unexplored. In this study, we have characterized the 3'-to-5' directed mRNA degradation in the yeast NMD pathway. PTC-mRNAs are stabilized in yeast cells lacking the components of 3'-to-S' mRNA-decay machinery. The 3'-to-5' directed degradation of PTC-mRNAs proceeds more rapidly than that of the PTC-free transcript, in a manner dependent on the cytoplasmic exosome and Upf proteins. Moreover, Upf1p, but not Upf2p, interacts physically with an N-terminal domain of Ski7p, although the interaction requires Upf2p. The efficiency of 3'-to-5' directed degradation of PTC-mRNAs is impaired by overexpression of Ski7p N-domain fragments that contain a sequence of the Upf1p-interaction region. These data suggest that the activation of 3'-to-5' directed NMD is mediated through the interaction between Upf1p and the Ski7p N domain. [ABSTRACT FROM AUTHOR]

Two cytoplasmic mRNA-decay pathways have been characterized in yeast, and both are initiated by shortening of the 3'-poty(A) tail. In the major 5'-to-3' decay pathway, the deadenylation triggers removal of the 5'-cap, exposing the transcript body for 5'-to-3' degradation. An alternative 3'-to-5' decay pathway also follows the deadenylation and requires two multi- complexes: the exosome containing various 3'-exonucteases and the Ski complex consisting of the RNA helicase Ski2p, Ski3p and Ski8p. In addition, Ski7p, which has an N-terminal domain and a C-terminal elongation factor la-like GTP-binding domain, is involved in the 3'-to-5' decay. However, physical interaction between the exosome and the Ski complex, together with the function of Ski7p, has remained unknown. Here we report that the N domain of Ski7p is required and sufficient for the 3'-to-5' decay. Furthermore, the exosome and the Ski complex interact with the different regions of Ski7p N domain, and both interactions are required for the 3'-to-5' decay. Thus, Ski7p G protein appears to function as a signal- coupling factor between the two multi-complexes operating in the 3'-to-5' mRNA-decay pathway. [ABSTRACT FROM AUTHOR]

Information processing by humans within themselves, e.g., such as reading letter characters, recognizing patterns, and other objects, and discriminating what they hear depends largely on the cerebral nerve. The human cerebrum learns various subjects and self-organizes the human neural network with plastic changes of synapses that arc formed through learning. Based on this viewpoint, many studies on neural network models and synaptic transfer efficiency have been reported from the engineering field. In this paper, the authors propose pulse-type hardware neuron models. These models employ pulse-type hardware cell body models which exhibit negative resistance characteristics and also chaos phenomena as reported in their earlier papers. The authors analyze the characteristics of the models and discuss an application of the models to a recognition circuit. Thai is, considering the subject of neurons, they propose pulse-type hardware models taking into account that information transmission is in a form of pulse repetition rate and that the synaptic weight which is equivalent to the transmission efficiency of synapses is subject to plastic changes. The pulse-type hardware neuron models employ pulse-type input/output circuits. The models are of a simple circuitry, consisting of a cell body section and a synaptic section. The cell body section employs V-shaped transistors. The synaptic section employs a CR time constant circuit to simulate the synaptic weight and a MOS variable capacitance device to simulate plastic changes of synapses. The authors propose two models. One type changes depending on learning signals which include functions of external signals such as teacher signal, as an example of the plastic change of synaptic weight The other model is of a type that changes depending on the input signal. The learning functions of the models are discussed by applying Hebb's rule as a typical learning rule. It is concluded that the pulse-type hardware neuron models provide methods for plastic synapse models with learning and memory functions, and also for synapse models with square characteristics. The neural network models made of these pulse-type hardware neuron models are effective for pattern recognition circuits, including vowel speech pattern recognition circuits. [ABSTRACT FROM AUTHOR]