Study on the Sodium-Doped Titania Interface-Type Memristor.

Memristors integrated into a crossbar-array architecture (CAA) are promising candidates for analog in-memory computing accelerators. However, the relatively low reliability of the memristor device and sneak current issues in CAA remain the main obstacles. Alkali ion-based interface-type memristors are promising solutions for implementing highly reliable memristor devices and neuromorphic hardware. This interface-type device benefits from self-rectifying and forming-free resistive switching (RS), and exhibits relatively low variation from device to device and cycle to cycle. In a previous report, we introduced an in situ grown Na/TiO2 memristor using atomic layer deposition (ALD) and proposed a RS mechanism from experimentally measured Schottky barrier modulation. Self-rectifying RS characteristics were observed by the asymmetric distribution of Na dopants and oxygen vacancies as the Ti metal used as the adhesion layer for the bottom electrode diffuses over the Pt electrode at 250 °C during the ALD process and is doped into the TiO2 layer. Here, we theoretically verify the modulation of the Schottky barrier at the TiO2/Pt electrode interface by Na ions. This study fabricated a Pt/Na/TiO2/Pt memristor device and confirmed its self-rectifying RS characteristics and stable retention characteristics for 24 h at 85 °C. Additionally, this device exhibited relative standard deviations of 27 and 7% in the high and low resistance states, respectively, in terms of cycle-to-cycle variation. To verify the RS mechanism, we conducted density functional theory simulations to analyze the impact of Na cations at interstitial sites on the Schottky barrier. Our findings can contribute to both fundamental understanding and the design of high-performance memristor devices for neuromorphic computing.

High-Reliability and Self-Rectifying Alkali Ion Memristor through Bottom Electrode Design and Dopant Incorporation.

Ionic memristor devices are crucial for efficient artificial neural network computations in neuromorphic hardware. They excel in multi-bit implementation but face challenges like device reliability and sneak currents in crossbar array architecture (CAA). Interface-type ionic memristors offer low variation, self-rectification, and no forming process, making them suitable for CAA. However, they suffer from slow weight updates and poor retention and endurance. To address these issues, the study demonstrated an alkali ion self-rectifying memristor with an alkali metal reservoir formed by a bottom electrode design. By adopting Li metal as the adhesion layer of the bottom electrode, an alkali ion reservoir was formed at the bottom of the memristor layer by diffusion occurring during the atomic layer deposition process for the Na:TiO2 memristor layer. In addition, Al dopant was used to improve the retention characteristics by suppressing the diffusion of alkali cations. In the memristor device with optimized Al doping, retention characteristics of more than 20 h at 125 °C, endurance characteristics of more than 5.5 × 105, and high linearity/symmetry of weight update characteristics were achieved. In reliability tests on 100 randomly selected devices from a 32 × 32 CAA device, device-to-device and cycle-to-cycle variations showed low variation values within 81% and 8%, respectively.

Effect of music on colonoscopy performance: A propensity score-matched analysis.

BACKGROUND: Music has been used to reduce stress and improve task performance during medical therapy. AIM: To assess the effects of music on colonoscopy performance outcomes. METHODS: We retrospectively reviewed patients who underwent colonoscopy performed by four endoscopists with popular music. Colonoscopy performance outcomes, such as insertion time, adenoma detection rate (ADR), and polyp detection rate (PDR), were compared between the music and non-music groups. To reduce selection bias, propensity score matching was used. RESULTS: After one-to-one propensity score matching, 169 colonoscopies were selected from each group. No significant differences in insertion time (4.97 vs 5.17 min, P = 0.795) and ADR (39.1% vs 46.2%, P = 0.226) were found between the two groups. Subgroup analysis showed that the insertion time (3.6 vs 3.8 min, P = 0.852) and ADR (51.1% vs 44.7%, P = 0.488) did not significantly differ between the two groups in experts. However, in trainees, PDR (46.9% vs 66.7%, P = 0.016) and ADR (25.9% vs 47.6%, P = 0.006) were significantly lower in the music than in the non-music group. CONCLUSION: The current study found that listening to music during colonoscopy did not affect procedure performance. Moreover, it suggested that music may distract trainees from appropriately detecting adenomas and polyps.

Vaccination in patients with inflammatory bowel disease-Asian perspectives: the results of a multinational web-based survey in the 8th Asian Organization for Crohn's and Colitis meeting.

BACKGROUND/AIMS: Long-term immunosuppressive therapies used to treat inflammatory bowel disease (IBD) are associated with an increased risk of infections, many of which can be prevented by vaccination. We assessed physicians' current approaches and clinical practices regarding vaccinations for IBD patients in different Asian countries/regions. METHODS: An internet-based survey was conducted among members of the Asian Organization for Crohn's and Colitis from September 2020 to November 2020. The questionnaire consisted of 2 parts covering general opinion on the relevance of vaccinations and clinical practice of vaccination. RESULTS: Overall, 384 Asian medical doctors responded to the survey. The majority of respondents considered it very (57.6%) or sufficiently (39.6%) important to perform vaccinations as recommended by the guidelines. About half of the Asian physicians (52.6%) were usually or always performing vaccinations. The influenza vaccine was the most frequently recommended vaccine for IBD patients. Half of the respondents (51.3%) did not recommend hepatitis A vaccine, especially in China (61.6%) and Japan (93.6%). The diphtheria, tetanus, and pertussis vaccine were never (35.2%) or rarely (29.4%) recommended. CONCLUSIONS: The findings of this survey indicated similarities among countries/regions in terms of the current approaches and practices regarding vaccination of IBD patients; however, there are some differences that might reflect each country's domestic vaccination guidelines and health insurance particularly with certain vaccines in some countries/regions. Although Asian physicians largely recommend vaccination, more awareness among doctors and Asian consensus regarding differences in IBD vaccination among countries/regions may be required.

Survey-Based Analysis of the Clinical Treatment Status of Irritable Bowel Syndrome in Korea.

BACKGROUND: The quality-of-life of patients with irritable bowel syndrome is low; incorrect diagnosis/treatment causes economic burden and inappropriate consumption of medical resources. This survey-based study aimed to analyze the current status of irritable bowel syndrome treatment to examine differences in doctors' perceptions of the disease, and treatment patterns. METHODS: From October 2019 to February 2020, the irritable bowel syndrome and Intestinal Function Research Study Group of the Korean Society of Neurogastroenterology and Motility conducted a survey on doctors working in primary, secondary, and tertiary healthcare institutions. The questionnaire included 37 items and was completed anonymously using the NAVER platform (a web-based platform), e-mails, and written forms. RESULTS: A total of 272 doctors responded; respondents reported using the Rome IV diagnostic criteria (amended in 2016) for diagnosing and treating irritable bowel syndrome. Several differences were noted between the primary, secondary, and tertiary physicians' groups. The rate of colonoscopy was high in tertiary healthcare institutions. During a colonoscopy, the necessity of random biopsy was higher among physicians who worked at tertiary institutions. 'The patient did not adhere to the diet' as a reason for ineffectiveness using low-fermentable oligo-, di-, and mono-saccharides, and polyols diet treatment was higher among physicians in primary/secondary institutions, and 'There are individual differences in terms of effectiveness' was higher among physicians in tertiary institutions. In irritable bowel syndrome constipation predominant subtype, the use of serotonin type 3 receptor antagonist (ramosetron) and probiotics was higher in primary/secondary institutions, while serotonin type 4 receptor agonist was used more in tertiary institutions. In irritable bowel syndrome diarrhea predominant subtype, the use of antispasmodics was higher in primary/secondary institutions, while the use of serotonin type 3 receptor antagonist (ramosetron) was higher in tertiary institutions. CONCLUSION: Notable differences were observed between physicians in primary/secondary and tertiary institiutions regarding the rate of colonoscopy, necessity of random biopsy, the reason for the ineffectiveness of low-fermentable oligo-, di-, and mono-saccharides, and polyols diet, and use of drug therapy in irritable bowel syndrome. In South Korea, irritable bowel syndrome is diagnosed and treated according to the Rome IV diagnostic criteria, revised in 2016.

Clinical outcomes and risk factors associated with poor prognosis after endoscopic resection of 10-20 mm rectal neuroendocrine tumors: a multicenter, retrospective study of 10-year experience.

BACKGROUND: The efficacy of endoscopic resection for of 10-20 mm rectal neuroendocrine tumor (NET) remains controversial. We aimed to evaluate the clinical outcomes and risk factors associated with poor prognosis after endoscopic resection of 10-20 mm rectal NET and to determine the optimal treatment. METHODS: Patients who underwent endoscopic resection for rectal NET in four tertiary hospitals were enrolled, and data on with the clinical outcomes and risk factors related to poor prognosis were retrospectively analyzed. RESULTS: A total of 105 patients who underwent endoscopic submucosal resection (ESD; n = 65, 61.9%), modified endoscopic mucosal resection (mEMR; n = 31, 29.5%), and conventional EMR (cEMR; n = 9, 8.6%) were enrolled. The mean follow-up period was 41.2 ± 21.9 months. In the morphologic findings, the mean diameter was 11.6 mm (range 10-19); the shape was sessile (50.5%) and mixed type (49.5%), and surface depression was observed in 41.9% of patients. In the histologic findings, 87.6% of patients had G1 and 12.4% G2 tumor grade, and 3.8% of patients had lymphovascular invasion. The overall en bloc and histologically complete (R0) resections were 99.1% and 76.2%, respectively. cEMR was a less-frequently developed R0 resection. In the univariate and multivariate analyses for R0 resection, only surface depression was significantly associated. Regional or distant organs metastasis during follow-up developed in three patients (2.9%) and was significantly associated with female sex, redness, G2 tumor grade, and non-ESD methods. CONCLUSION: Patients who underwent endoscopic resection of 10-20 mm rectal NET had good prognosis; therefore, endoscopic resection can be considered as the first-line treatment, particularly for 10-14 mm rectal NET. However, the risk factors, such as female sex, redness, G2 tumor grade and non-ESD methods, were associated with regional or distant metastases during follow-up. Therefore, patients with these risk factors should be carefully monitored.

The effect of biological agent on body composition in patients with Crohn's disease.

BACKGROUND: Crohn's disease (CD) is associated with altered body composition, affecting clinical outcomes. We evaluated the impact of biologics on body composition in CD patients. METHODS: This multicenter longitudinal study across four Korean university hospitals conducted from January 2009 to August 2021 retrospectively reviewed data of CD patients with abdominal computed tomography (CT) before and after the biologic treatment. Skeletal muscle area (SMA), visceral fat area (VFA), and subcutaneous fat area (SFA) of the third lumbar vertebra (L3) on CT were measured. Myopenia was defined as L3 skeletal muscle index (SMI) of < 49 and < 31 cm2/m2 for men and women, respectively. RESULTS: Among 112 participants, 79 (70.5%) had myopenia. In the myopenia group, all body composition parameters were significantly increased after the biologic treatment: SMI (37.68 vs. 39.40 cm2/m2; P < 0.001), VFA (26.12 vs. 54.61 cm2; P < 0.001), SFA (44.29 vs. 82.42 cm2; P < 0.001), while no significant differences were observed in the non-myopenia group. In multivariate analysis, penetrating CD (hazard ratio, 5.40; P = 0.020) was the independent prognostic factor for surgery. Operation-free survival rate tended to decrease in the myopenia group (Log-rank test, P = 0.090). CONCLUSIONS: Biological agents can increase all body composition parameters in CD patients with myopenia. These patients are more likely to experience surgery.

Outcomes according to treatment modalities as a bridge to curative surgery for malignant obstruction of the proximal colon: stent versus stoma.

BACKGROUND/AIMS: The optimal treatment for acute malignant obstruction of the proximal colon (MOPC, proximal to the splenic flexure) remains challenging. Emergency resection, the traditional modality for MOPC, has shown significantly high mortality and morbidity rates, according to recent studies. This study aimed to investigate the clinical outcomes of stent vs stoma as a bridge to curative surgery for MOPC. METHODS: This retrospective cohort study included 72 patients who underwent endoscopic placement of a self-expanding metallic stent (SEMS) or loop ileostomy for MOPC at six referral centers between January 2011 and July 2021. Clinical and pathological characteristics, procedure-related complications, and long-term mortality rates after curative surgery were analyzed. RESULTS: During a mean follow-up period of 32 months, 30 patients (41.7%) underwent ileostomy preferentially for more proximal cancer, complete obstruction, and advanced tumor stage compared to the SEMS group. No difference was found in procedure-related complications, but five deaths were observed after ileostomy. Survival analysis for 5-year mortality after curative surgery showed no significant difference between the bridge modalities (log-rank p = 0.253). CONCLUSION: In this study, SEMS as a bridge to surgery showed relatively safe results in terms of post-procedural mortality. However, these results should be considered when performing ileostomy in patients with more advanced malignant obstruction.

Gastric wall abscess after endoscopic submucosal dissection.

Gastric wall abscess, a localized form of phlegmonous gastritis, is a rare complication of endoscopic resection. We report the first case of gastric wall abscess developing after endoscopic submucosal dissection in Korea. A 72-year-old woman visited our clinic to receive treatment for gastric adenoma. The patient successfully underwent endoscopic submucosal dissection with no complications. The final diagnosis was well-differentiated tubular adenocarcinoma. We performed follow-up endoscopy 10 weeks later and found a large subepithelial lesion on the posterior wall of the gastric antrum. Abdominal computed tomography revealed hypodense wall thickening and a 5 cm heterogenous multilobular mass in the submucosal layer of the gastric antrum. Submucosal invasion with mucin-producing adenocarcinomas could therefore not be excluded. The patient agreed to undergo additional gastrectomy due to the possibility of a highly malignant lesion. The final diagnosis was acute suppurative inflammation with the formation of multiple abscesses in the mural layers and omentum. The patient was discharged with no complications.

Korean clinical practice guidelines on biologics for moderate to severe Crohn's disease.

Crohn's disease (CD) is a relapsing and progressive condition characterized by diarrhea, abdominal pain, weight loss, and hematochezia that results in serious complications such as perforations, fistulas, and abscesses. Various medications, interventions, and surgical treatments have been used to treat CD. The Korean guidelines for CD management were distributed in 2012 and revised in 2017 by the Inflammatory Bowel Disease (IBD) Research Group of the Korean Association for the Study of Intestinal Diseases. Substantial progress in mucosal immunologic research has elucidated the pathophysiology of IBD, leading to development of biological agents for treatment of CD. The first developed biologic agent, tumor necrosis factor-α agents, were shown to be efficacious in CD, heralding a new era in management of CD. Subsequently, vedolizumab, a monoclonal antibody against integrin α4ß7, and ustekinumab, a human monoclonal antibody that inhibits the common p40 subunit of interleukin-12 and interleukin-23, were both approved for clinical use and are efficacious and safe for both induction and maintenance of remission in moderate-to-severe CD patients. Moreover, a recent study showed the non-inferiority of CT-P13, an infliximab biosimilar, compared with infliximab in CD patients. The third Korean guidelines for CD management provide updated information regarding treatment of moderate-to-severe CD patients with biologic agents.

Gastric CD56-negative Extranodal Natural Killer/T-cell Lymphoma: A Case Report.

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKTCL-NT) is the most common subtype of Epstein-Barr virus-associated NK/T-cell lymphomas. ENKTCL-NT occurs infrequently in the gastrointestinal tract. In particular, reports of ENKTCL-on NT arising from the stomach are extremely rare. Several clusters of differentiation (CDs) have been useful in recognizing NK-cells, T-cells, and tumor cells of NK/T-cell lymphomas. Among them, the CD56 antigen is considered the most sensitive marker for ENKTCL-NT and is expressed in almost all cases of ENKTCL-NT. Thus, the development of CD56-negative ENKTCL-NT is highly atypical. This paper reports a case of a young Asian female who presented with gastric ulcer bleeding. The patient was histologically diagnosed with ENKTCL-NT. No tumor cells for CD56 were observed, whereas no monoclonality of the T-cell receptor gamma gene rearrangement was detected in the tumor cells. The patient was scheduled for systemic chemotherapy six times and achieved complete remission. Peripheral blood-hematopoietic stem cell transplantation was performed later.

Filamentary and Interface-Type Memristors Based on Tantalum Oxide for Energy-Efficient Neuromorphic Hardware.

To implement artificial neural networks (ANNs) based on memristor devices, it is essential to secure the linearity and symmetry in weight update characteristics of the memristor, and reliability in the cycle-to-cycle and device-to-device variations. This study experimentally demonstrated and compared the filamentary and interface-type resistive switching (RS) behaviors of tantalum oxide (Ta2O5 and TaO2)-based devices grown by atomic layer deposition (ALD) to propose a suitable RS type in terms of reliability and weight update characteristics. Although Ta2O5 is a strong candidate for memristor, the filament-type RS behavior of Ta2O5 does not fit well with ANNs demanding analog memory characteristics. Therefore, this study newly designed an interface-type TaO2 memristor and compared it to a filament type of Ta2O5 memristor to secure the weight update characteristics and reliability. The TaO2-based interface-type memristor exhibited gradual RS characteristics and area dependency in both high- and low-resistance states. In addition, compared to the filamentary memristor, the RS behaviors of the TaO2-based interface-type device exhibited higher suitability for the neuromorphic, symmetric, and linear long-term potentiation (LTP) and long-term depression (LTD). These findings suggest better types of memristors for implementing ionic memristor-based ANNs among the two types of RS mechanisms.

Efficacy of a Restrictive Diet in Irritable Bowel Syndrome: A Systematic Review and Network Meta-analysis.

Background/Aims: Dietary factors can aggravate the symptoms of irritable bowel syndrome (IBS). Many IBS patients try restrictive diets to relieve their symptoms, but the types of diets with an exacerbating factor are unknown. Therefore, this paper reports the results of a systematic review and network meta-analysis of randomized-controlled trials (RCTs) reviewing the efficacy of food restriction diets in IBS. Methods: The MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Clinicaltrials.gov databases were searched until July 21, 2021, to retrieve RCTs assessing the efficacy of restriction diets in adults with IBS. Two independent reviewers performed the eligibility assessment and data abstraction. RCTs that evaluated a restriction diet versus a control diet and assessed the improvement in global IBS symptoms were included. These trials reported a dichotomous assessment of the overall response to therapy. Results: A total of 1,949 citations were identified. After full-text screening, 14 RCTs were considered eligible for the systematic review and network meta-analysis. A starch- and sucrose-reduced diet and a diet with low-fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) showed significantly better results than a usual diet. Symptom flare-ups in patients on a gluten- free diet were also significantly lower than in those on high-gluten diets. Conclusions: These findings showed that the starch- and sucrose-reduced, low FODMAP, and gluten-free diets had superior effects in reducing IBS symptoms. Further studies, including head-to-head trials will be needed to establish the effectiveness of dietary restrictions on IBS symptoms.

Role of multidetector computed tomography in patients with acute infectious colitis.

BACKGROUND: The role of multidetector computed tomography (MDCT) in patients with acute infectious colitis is still unclear. AIM: To examine the usefulness of MDCT in distinguishing the etiology of acute infectious colitis. METHODS: Overall, 244 patients who met the criteria for acute infectious colitis and visited the Hospital from February 2015 to 2018 were retrospectively enrolled and divided into two groups (bacterial: 204, viral: 40) according to causes of acute colitis, based on stool PCR. Eleven MDCT parameters, including wall thickening, submucosal edema, mucosal enhancement, serosa involvement, empty colon sign, small bowel involvement, comb sign, continuous distribution, accordion sign, mucosal thickening, and lymph node enlargement, were constructed in a blinded fashion. RESULTS: MDCT parameters of wall thickening (OR: 13.60; 95%CI: 5.80-31.88; P < 0.001), submucosal edema (OR: 36.08; 95%CI: 13.54-96.13; P < 0.001), mucosal enhancement (OR: 22.55; 95%CI: 9.28-54.81; P < 0.001), serosal involvement (OR: 14.50; 95%CI: 3.33-63.23; P < 0.001), empty colon sign (OR: 6.68; 95%CI: 2.44-18.32; P < 0.001), continuous distribution (OR: 24.09; 95%CI: 9.38-61.90; P < 0.001), accordion sign (OR: 9.02; 95%CI: 1.12-72.35; P = 0.038), mucosal thickening (OR: 46.41; 95%CI: 10.38-207.51; P < 0.001), and lymph node enlargement (OR: 4.39; 95%CI: 1.22-15.72; P = 0.023) were significantly associated with bacterial colitis. At least one positive finding in four CT outcomes (submucosal edema, mucosal enhancement, continuous distribution, mucosal thickening) in summer showed a high probability of bacterial colitis (sensitivity, 41.67; specificity, 92.50; OR: 24.95). CONCLUSION: MDCT provides many clues that can be useful in suggesting a specific etiology of acute infectious colitis.

Bipolar Resistive Switching in Lanthanum Titanium Oxide and an Increased On/Off Ratio Using an Oxygen-Deficient ZnO Interlayer.

The present study pioneered an oxygen migration-driven metal to insulator transition Mott memory, a new type of nonvolatile memory using lanthanum titanium oxide (LTO). We first show the reset first bipolar property without an initial electroforming process in LTO. We used oxygen-deficient ZnO as an interlayer between LTO and a W electrode to clarify whether oxygen migration activates LTO as the Mott transition. ZnO oxygen deficiency provides oxygen ion migration paths as well as a reservoir, facilitating oxygen migration from LTO to the W electrode. Thus, including the ZnO interlayer improved oxygen migration between LTO and the W electrode, achieving a 10-fold increased on/off current ratio. The current research contributes to a better understanding of valence change Mott memory by exploring the LTO resistive switching mechanism and ZnO interlayer influences on the oxygen migration process.

Morphologic Changes in Esophageal Body Movement During Bolus Transport After Peroral Endoscopic Myotomy in Type III Achalasia.

BACKGROUND/AIMS: The effect of peroral endoscopic myotomy (POEM) on esophageal body movement in achalasia is poorly understood. This study aims to evaluate morphological changes in esophageal body movement after POEM in type III achalasia by analyzing intraluminal ultrasound (US) images in comparison to type I and II achalasia. METHODS: Intraluminal US images and impedance values of the distal esophagus from 47 achalasia patients who underwent POEM or pneumatic dilatation (PD) (30 patients in the POEM group and 17 patients in the PD group) with pre- and post-procedural high-resolution impedance manometry and intraluminal US examinations were analyzed. The muscle thickness (MT), muscle cross-sectional area, lumen cross-sectional area (LCSA), contractility and distensibility indices, swallow-to-distension interval, and distension duration during each bolus transport were analyzed. RESULTS: The MT increased and LCSA decreased significantly (P < 0.001), but the contractility index was not improved after POEM or PD in type I achalasia. Baseline MT increased and LCSA decreased significantly after POEM and PD in type II achalasia (P < 0.001). In contrast, MT and the swallow-to-distension interval decreased and the distension LCSA/duration and contractility index increased after POEM in type III achalasia (P < 0.001). In contrast to type I and II achalasia, in type III achalasia, these effects were unique to the POEM group. CONCLUSIONS: POEM decreased the esophageal LCSA by decreasing intrabolus pressure without improving contractility in type I and II achalasia. In contrast, POEM increased esophageal body distension and contractility and improved the inhibitory process during bolus transport in type III achalasia.

Clinical Efficacy of Probiotic Therapy on Bowel-Related Symptoms in Patients with Ulcerative Colitis during Endoscopic Remission: An Observational Study.

BACKGROUND: A substantial percentage of patients with ulcerative colitis (UC) have irritable bowel syndrome- (IBS-) like symptoms despite adequate treatment and endoscopic remission. In this study, we evaluated the clinical efficacy of probiotic therapy for residual IBS-like symptoms in patients with UC in endoscopic remission. METHODS: We conducted a multicenter, observational study between April 2018 and December 2020 across two university hospitals in Korea. Patients with UC whose IBS-like symptoms persisted during endoscopic remission were included in this study. Endoscopic remission was defined as a Mayo endoscopic score ≤ 1, and IBS-like symptoms were defined as those meeting the ROME-IV diagnostic criteria. A Biotop capsule® (Lactobacillus acidophilus, 75 mg; Clostridium butyricum TO-A, 25 mg; Bacillus mesentericus TO-A, 25 mg; and Streptococcus faecalis T-110, 5 mg) was administered three times daily for one month. All patients completed bowel-related symptom questionnaires and short inflammatory bowel disease questionnaires (SIBDQs) at the start and end of the 4-week treatment period. RESULTS: A total of 43 patients were enrolled and analyzed. Statistically significant improvements from baseline were observed at the end of the 4-week treatment. The total SIBDQ score improved from 50.6 to 53.6 (P = 0.005). SIBDQ scores of bowel function (P = 0.018), systemic function (P = 0.040), and social function (P = 0.005) improved. Stool frequency and Bristol stool scale scores improved after probiotic therapy (P < 0.05). CONCLUSION: This study showed that probiotic administration improved bowel-related symptoms and quality of life in patients with UC whose IBS-like symptoms persisted during endoscopic remission. As this is an observational study and has no placebo-controlled arm, further prospective randomized controlled trials are needed to confirm these results.

Linear and Symmetric Li-Based Composite Memristors for Efficient Supervised Learning.

Emerging energy-efficient neuromorphic circuits are based on hardware implementation of artificial neural networks (ANNs) that employ the biomimetic functions of memristors. Specifically, crossbar array memristive architectures are able to perform ANN vector-matrix multiplication more efficiently than conventional CMOS hardware. Memristors with specific characteristics, such as ohmic behavior in all resistance states in addition to symmetric and linear long-term potentiation/depression (LTP/LTD), are required in order to fully realize these benefits. Here, we demonstrate a Li-based composite memristor (LCM) that achieves these objectives. The LCM consists of three phases: Li-doped TiO2 as a Li reservoir, Li4Ti5O12 as the insulating phase, and Li7Ti5O12 as the metallic phase, where resistive switching correlates with the change in the relative fraction of the metallic and insulating phases. The LCM exhibits a symmetric and gradual resistive switching behavior for both set and reset operations during a full bias sweep cycle. This symmetric and linear weight update is uniquely enabled by the symmetric bidirectional migration of Li ions, which leads to gradual changes in the relative fraction of the metallic phase in the film. The optimized LCM in ANN simulation showed that exceptionally high accuracy in image classification is realized in fewer training steps compared to the nonlinear behavior of conventional memristors.

Sodium-Doped Titania Self-Rectifying Memristors for Crossbar Array Neuromorphic Architectures.

Memristors integrated into a crossbar-array architecture (CAA) are promising candidates for nonvolatile memory elements in artificial neural networks. However, the relatively low reliability of memristors coupled with crosstalk and sneak currents in CAAs have limited the realization of the full potential of this technology. Here, high-reliability Na-doped TiO2  memristors grown in situ by atomic layer deposition (ALD) are demonstrated, where reversible Na migration underlies the resistive-switching mechanism. By employing ALD growth with an aqueous NaOH reactant in deionized water, uniform implantation of Na dopants is achieved in the crystallized TiO2  thin films at 250 °C without post-annealing. The resulting Na-doped TiO2  memristors show electroforming-free and self-rectifying resistive-switching behavior, and they are ideally suited for selectorless CAAs. Effective addressing of selectorless nodes is demonstrated via electrical measurement of individual memristors in a 6 × 6 crossbar using a read current of less than 1 µA with negligible sneak current at or below the noise level of ≈100 pA. Finally, the long-term potentiation and depression synaptic behavior from these Na-doped TiO2  memristors achieves greater than 99.1% accuracy for image-recognition tasks using a convolutional neural network based on the selectorless of crossbar arrays.